Timing of onset of persistent critical illness: a multi-centre retrospective cohort study

The interplay between frailty status and persistent critical illness on the outcomes of patients with critical COVID-19: A population-based retrospective cohort study

OBJECTIVES

Persistent critical illness (PerCI) occurs when the patient's prolonged intensive care unit (ICU) stay results in complications that become the primary drivers of their condition, rather than the initial reason for their admission. Patients with frailty have a higher risk of developing and dying from PerCI. We aimed to investigate the interplay of frailty and PerCI in critically ill patients with COVID-19.

METHOD

We conducted a retrospective multicentre cohort study including 103 Australian and New Zealand ICUs over the period of January 2020 to December 2021. We included all adult patients with COVID-19 and documented the Clinical Frailty Scale (frail ≥ 5). PerCI is defined as an ICU length of stay of ≥10 days. We aimed to investigate the hospital mortality with and without PerCI across varying degrees of frailty and examined the potential interaction effect between frailty status and PerCI.

RESULTS

The prevalence of PerCI was similar between patients with and without frailty (25.4% vs. 27.9%; p = 0.44). Hospital mortality was higher in patients with PerCI than in those without (28.8% vs. 9.3%; p < 0.001). Mortality in patients with PerCI also increased with increasing frailty (p < 0.001). Frailty independently predicted hospital mortality. When adjusted for Australia and New Zealand risk of death mortality prediction model and sex, the impact of frailty was no different in patients with and without PerCI (odds ratio = 1.30 [95% confidence interval: 1.14-1.49] vs. (odds ratio = 1.46 [95% confidence interval: 1.29-1.64]). Furthermore, increasing frailty did not influence mortality in patients with PerCI more (or less) than in those without PerCI (pinteraction = 0.82).

CONCLUSIONS

The presence of frailty independently predicted hospital mortality in patients with PerCI with COVID-19, but the impact of frailty on mortality was no different in those who developed PerCI from those without PerCI.

Lower gastrointestinal tract dysbiosis in persistent critical illness: a systematic review

Introduction. The human lower gastrointestinal tract microbiome is complex, dynamic and prone to disruption occurring during critical illness.Hypothesis or gap statement. The characteristics of lower gastrointestinal tract microbiome disruption and its association with clinical outcomes in patients with prolonged intensive care stay remain uncertain.Aim. To systematically review studies describing lower gastrointestinal tract molecular sequencing in patients with prolonged intensive care stay and explore associations with clinical outcomes.Methodology. This systematic review was prospectively registered and follows the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. OVID MEDLINE, EMBASE and The Cochrane Central Register of Controlled Trials databases were searched for eligible studies describing adults and/or children who underwent molecular sequencing of stool or rectal samples taken on or after 10 days of intensive care.Results. There were 13 studies with 177 patients included. The overall certainty of evidence was low, and no studies reported mortality. Reduced alpha diversity was observed in nine out of nine studies but was not associated with clinical outcomes in four out of four studies. Longitudinal alpha diversity decreased in five out of six studies, and inter-individual beta diversity increased in five out of five studies. After approximately one week of intensive care unit admission, rapid fluctuations in dominant taxa stabilized with trajectories of either recovery or deterioration in five studies. Pathogenic enrichment and commensal depletion were reported in all 13 studies and associated with clinical outcomes in two studies.Conclusion. Lower gastrointestinal tract microbiome disruption is highly prevalent and has consistent characteristics in patients with prolonged intensive care stay. Amongst reported metrics, only relative taxon abundance was associated with clinical outcomes.

Urea to creatinine ratio as a predictor of persistent critical illness

INTRODUCTION

Persistent critical illness (PCI) is a syndrome in which the acute presenting problem has been stabilized, but the patient's clinical state does not allow ICU discharge. The burden associated with PCI is substantial. The most obvious marker of PCI is prolonged ICU length of stay (LOS), usually greater than 10 days. Urea to Creatinine ratio (UCr) has been suggested as an early marker of PCI development.

METHODS

A single-center retrospective study. Data of patients admitted to a general mixed medical-surgical ICU during Jan 1st 2018 till Dec 31st 2022 was extracted, including demographic data, baseline characteristics, daily urea and creatinine results, renal replacement therapy (RRT) provided, and outcome measures - length of stay, and mortality (ICU, and 90 days). Patients were defined as PCI patients if their LOS was >10 days. We used Fisher exact test or Chi-square to compare PCI and non-PCI patients. The association between UCr with PCI development was assessed by repeated measures linear model. Multivariate Cox regression was used for 1 year mortality assessment.

RESULTS

2098 patients were included in the analysis. Patients who suffered from PCI were older, with higher admission prognostic scores. Their 90-day mortality was significantly higher than non-PCI patients (34.58% vs 12.18%, p < 0.0001). A significant difference in UCr was found only on the first admission day among all patients. This was not found when examining separately surgical, trauma, or transplantation patients. We did not find a difference in UCr in different KDIGO (Kidney Disease Improving Global Outcomes) stages. Elevated UCr and PCI were found to be significantly associated with 1 year mortality.

CONCLUSION

In this single center retrospective cohort study, UCr was not found to be associated with PCI development.

Nutritional and metabolic modulation of inflammation in critically ill patients: a narrative review of rationale, evidence and grey areas

BACKGROUND

Inflammation is the hallmark of critical illness and triggers the neuro-endocrine stress response and an oxidative stress. Acute inflammation is initially essential for patient's survival. However, ongoing or exaggerated inflammation, due to persistent organ dysfunction, immune dysfunction or poor inflammation resolution, is associated to subsequent hypermetabolism and hypercatabolism that severely impact short and long-term functional status, autonomy, as well as health-related costs. Modulation of inflammation is thus tempting, with the goal to improve the short- and long-term outcomes of critically ill patients.

FINDINGS

Inflammation can be modulated by nutritional strategies (including the timing of enteral nutrition initiation, the provision of some specific macronutrients or micronutrients, the use of probiotics) and metabolic treatments. The most interesting strategies seem to be n-3 polyunsaturated fatty acids, vitamin D, antioxidant micronutrients and propranolol, given their safety, their accessibility for clinical use, and their benefits in clinical studies in the specific context of critical care. However, the optimal doses, timing and route of administration are still unknown for most of them. Furthermore, their use in the recovery phase is not well studied and defined.

CONCLUSION

The rationale to use strategies of inflammation modulation is obvious, based on critical illness pathophysiology and based on the increasingly described effects of some nutritional and pharmacological strategies. Regretfully, there isn't always substantial proof from clinical research regarding the positive impacts directly brought about by inflammation modulation. Some arguments come from studies performed in severe burn patients, but such results should be transposed to non-burn patients with caution. Further studies are needed to explore how the modulation of inflammation can improve the long-term outcomes after a critical illness.

Nutrition considerations for patients with persistent critical illness: A narrative review

Critically ill patients experience high rates of malnutrition and significant muscle loss during their intensive care unit (ICU) admission, impacting recovery. Nutrition is likely to play an important role in mitigating the development and progression of malnutrition and muscle loss observed in ICU, yet definitive clinical trials of nutrition interventions in ICU have failed to show benefit. As improvements in the quality of medical care mean that sicker patients are able to survive the initial insult, combined with an aging and increasingly comorbid population, it is anticipated that ICU length of stay will continue to increase. This review aims to discuss nutrition considerations unique to critically ill patients who have persistent critical illness, defined as an ICU stay of >10 days. A discussion of nutrition concepts relevant to patients with persistent critical illness will include energy and protein metabolism, prescription, and delivery; monitoring of nutrition at the bedside; and the role of the healthcare team in optimizing nutrition support.

CHRONIC CRITICAL ILLNESS-INDUCED MUSCLE ATROPHY: INSIGHTS FROM A TRAUMA MOUSE MODEL AND POTENTIAL MECHANISM MEDIATED VIA SERUM AMYLOID A

ABSTRACT

Background: Chronic critical illness (CCI), which was characterized by persistent inflammation, immunosuppression, and catabolism syndrome (PICS), often leads to muscle atrophy. Serum amyloid A (SAA), a protein upregulated in critical illness myopathy, may play a crucial role in these processes. However, the effects of SAA on muscle atrophy in PICS require further investigation. This study aims to develop a mouse model of PICS combined with bone trauma to investigate the mechanisms underlying muscle weakness, with a focus on SAA. Methods: Mice were used to examine the effects of PICS after bone trauma on immune response, muscle atrophy, and bone healing. The mice were divided into two groups: a bone trauma group and a bone trauma with cecal ligation and puncture group. Tibia fracture surgery was performed on all mice, and PICS was induced through cecal ligation and puncture surgery in the PICS group. Various assessments were conducted, including weight change analysis, cytokine analysis, hematological analysis, grip strength analysis, histochemical staining, and immunofluorescence staining for SAA. In vitro experiments using C2C12 cells (myoblasts) were also conducted to investigate the role of SAA in muscle atrophy. The effects of inhibiting receptor for advanced glycation endproducts (RAGE) or JAK2 on SAA-induced muscle atrophy were examined. Bioinformatic analysis was conducted using a dataset from the GEO database to identify differentially expressed genes and construct a coexpression network. Results: Bioinformatic analysis confirmed that SAA was significantly upregulated in muscle tissue of patients with intensive care unit-induced muscle atrophy. The PICS animal models exhibited significant weight loss, spleen enlargement, elevated levels of proinflammatory cytokines, and altered hematological profiles. Evaluation of muscle atrophy in the animal models demonstrated decreased muscle mass, grip strength loss, decreased diameter of muscle fibers, and significantly increased expression of SAA. In vitro experiment demonstrated that SAA decreased myotube formation, reduced myotube diameter, and increased the expression of muscle atrophy-related genes. Furthermore, SAA expression was associated with activation of the FOXO signaling pathway, and inhibition of RAGE or JAK2/STAT3-FOXO signaling partially reversed SAA-induced muscle atrophy. Conclusions: This study successfully develops a mouse model that mimics PICS in CCI patients with bone trauma. Serum amyloid A plays a crucial role in muscle atrophy through the JAK2/STAT3-FOXO signaling pathway, and targeting RAGE or JAK2 may hold therapeutic potential in mitigating SAA-induced muscle atrophy.

Persistent Critical Illness and Long-Term Outcomes in Patients With COVID-19: A Multicenter Retrospective Cohort Study

OBJECTIVES

A nontrivial number of patients in ICUs experience persistent critical illness (PerCI), a phenomenon in which features of the ICU course more consistently predict mortality than the initial indication for admission. We aimed to describe PerCI among patients with critical illness caused by COVID-19, and these patients' short- and long-term outcomes.

DESIGN

Multicenter retrospective cohort study.

SETTING

Australian and New Zealand Intensive Care Society Adult Patient Database of 114 Australian ICUs between January 1, 2020, and March 31, 2022.

PATIENTS

Patients 16 years old or older with COVID-19, and a documented ICU length of stay.

EXPOSURE

The presence of PerCI, defined as an ICU length of stay greater than or equal to 10 days.

MEASUREMENTS

We compared the survival time up to 2 years from ICU admission using time-varying robust-variance estimated Cox proportional hazards models. We further investigated the impact of PerCI in subgroups of patients, stratifying based on whether they survived their initial hospitalization.

MAIN RESULTS

We included 4961 patients in the final analysis, and 882 patients (17.8%) had PerCI. ICU mortality was 23.4% in patients with PerCI and 6.5% in those without PerCI. Patients with PerCI had lower 2-year (70.9% [95% CI, 67.9-73.9%] vs. 86.1% [95% CI, 85.0-87.1%]; p < 0.001) survival rates compared with patients without PerCI. Patients with PerCI had higher mortality (adjusted hazards ratio: 1.734; 95% CI, 1.388-2.168); this was consistent across several sensitivity analyses. When analyzed as a nonlinear predictor, the hazards of mortality were inconsistent up until 10 days, before plateauing.

CONCLUSIONS

In this multicenter retrospective observational study patients with PerCI tended to have poorer short-term and long-term outcomes. However, the hazards of mortality plateaued beyond the first 10 days of ICU stay. Further studies should investigate predictors of developing PerCI, to better prognosticate long-term outcomes.

Survivorship outcomes for critically ill patients in Australia and New Zealand: A scoping review

INTRODUCTION

Impairments after critical illness, termed the post-intensive care syndrome, are an increasing focus of research in Australasia. However, this research is yet to be cohesively synthesised and/or summarised.

OBJECTIVE

The aim of this scoping review was to explore patient outcomes of survivorship research, identify measures, methodologies, and designs, and explore the reported findings in Australasia.

INCLUSION CRITERIA

Studies reporting outcomes for adult survivors of critical illness from Australia and New Zealand in the following domains: physical, functional, psychosocial, cognitive, health-related quality of life (HRQoL), discharge destination, health care use, return to work, and ongoing symptoms/complications of critical illness.

METHODS

The Joanna Briggs Institute scoping review methodology framework was used. A protocol was published on the open science framework, and the search used Ovid MEDLINE, Scopus, ProQuest, and Google databases. Eligible studies were based on reports from Australia and New Zealand published in English between January 2000 and March 2022.

RESULTS

There were 68 studies identified with a wide array of study aims, methodology, and designs. The most common study type was nonexperimental cohort studies (n = 17), followed by studies using secondary analyses of other study types (n = 13). HRQoL was the most common domain of recovery reported. Overall, the identified studies reported that impairments and activity restrictions were associated with reduced HRQoL and reduced functional status was prevalent in survivors of critical illness. About 25% of 6-month survivors reported some form of disability. Usually, by 6 to12 months after critical illness, impairments had improved.

CONCLUSIONS

Reports of long-term outcomes for survivors of critical illness in Australia highlight that impairments and activity limitations are common and are associated with poor HRQoL. There was little New Zealand-specific research related to prevalence, impact, unmet needs, ongoing symptoms, complications from critical illness, and barriers to recovery.

Long-stay ICU patients with frailty: mortality and recovery outcomes at 6 months

BACKGROUND

Prolonged intensive care unit (ICU) stay is associated with physical, cognitive, and psychological disabilities. The impact of baseline frailty on long-stay ICU patients remains uncertain. This study aims to investigate how baseline frailty influences mortality and post-ICU disability 6 months after critical illness in long-stay ICU patients.

METHODS

In this retrospective cohort study, we assessed patients hospitalized for ≥ 7 days in the ICU between May 2018 and May 2021, following them for up to 6 months or until death. Based on the Clinical Frailty Scale (CFS) at ICU admissions, patients were categorized as frail (CFS ≥ 5), pre-frail (CFS 3-4) and non-frail (CFS 1-2). Kaplan-Meier curves and a multivariate Cox model were used to examine the association between frailty and mortality. At the 6 month follow-up, we assessed psychological, physical, cognitive outcomes, and health-related quality of life (QoL) using descriptive statistics and linear regressions.

RESULTS

We enrolled 531 patients, of which 178 (33.6%) were frail, 200 (37.6%) pre-frail and 153 (28.8%) non-frail. Frail patients were older, had more comorbidities, and greater disease severity at ICU admission. At 6 months, frail patients presented higher mortality rates than pre-frail and non-frail patients (34.3% (61/178) vs. 21% (42/200) vs. 13.1% (20/153) respectively, p < 0.01). The rate of withdrawing or withholding of care did not differ significantly between the groups. Compared with CFS 1-2, the adjusted hazard ratios of death at 6 months were 1.7 (95% CI 0.9-2.9) for CFS 3-4 and 2.9 (95% CI 1.7-4.9) for CFS ≥ 5. At 6 months, 192 patients were seen at a follow-up consultation. In multivariate linear regressions, CFS ≥ 5 was associated with poorer physical health-related QoL, but not with poorer mental health-related QoL, compared with CFS 1-2.

CONCLUSION

Frailty is associated with increased mortality and poorer physical health-related QoL in long-stay ICU patients at 6 months. The admission CFS can help inform patients and families about the complexities of survivorship during a prolonged ICU stay.

Chronic critical illness after trauma injury: outcomes and experience in a trauma center

OBJECTIVE

To determine the prevalence, risk factors and functional results of chronic critical illness (CCI) in polytrauma patients.

DESIGN

Single-center observational retrospective study.

SETTING

ICU at a tertiary hospital in Santander, Spain, between 2015 and 2019.

PATIENTS

Adult trauma patients who survived beyond 48 h after injury. CCI was defined as the need for mechanical ventilation for at least 14 days or tracheostomy for difficult weaning.

MEASUREMENTS AND MAIN RESULTS

About 62/575 developed CCI. These patients were characterized by higher ISS score [17 (SD 10) vs. 13.8 (SD 8.2); p < 0.001] and higher NISS (26 (SD 11) vs. 19.2 (SD 10.5); p = 0.001). CCI group had greater proportion of hospital-acquired infections (100% vs. 18.1%; p < 0.001), and acute kidney failure (33.9% vs. 22.8% p < 0.001). During the first 24 h of admission, CCI group required in a greater proportion surgical intervention (50% vs. 29%; p = 0.001), and blood products (31.3% vs. 20.5%; p < 0.047). Hospital ward stay was longer in CCI patients [9.5 days (IQR 5-16.9) vs. 43.9 (IQR 30.3-53) p < 0.001]. The CCI mortality was higher (19.5% vs. 8.1%; p = 0.004). Surgical intervention in the first 24 h (OR 2.5 95% CI 1.1-4.1), age (> 55 years) (OR 2.1 95%CI 1.1-4.2), ISS score (OR 1.1 95%CI 1.02-1.3), GCS score (OR 0.8 95%CI 0.4-23.2) and multiple organ failure (OR 9.5 95%CI 3.9-23.2) were predictors of CCI in the multivariate analysis.

CONCLUSIONS

CCI after severe trauma appears in a considerable proportion of patients. Early identification and implementation of specific interventions could change the evolution of this process.

Body composition and muscle strength at the end of ICU stay are associated with 1-year mortality, a prospective multicenter observational study

BACKGROUND & AIMS

After a prolonged intensive care unit (ICU) stay patients experience increased mortality and morbidity. The primary aim of this study was to assess the prognostic value of nutritional status, body mass composition and muscle strength, as assessed by body mass index (BMI), bioelectrical impedance analysis (BIA), handgrip (HG) test, and that of the biological features to predict one-year survival at the end of a prolonged ICU stay.

METHODS

This was a multicenter prospective observational study. Survivor patients older than 18 years with ICU length of stay >72 h were eligible for inclusion. BIA and HG were performed at the end of the ICU stay. Malnutrition was defined by BMI and fat-free mass index (FFMI). The primary endpoint was one-year mortality. Multivariable logistic regression was performed to determine parameters associated with mortality.

RESULTS

572 patients were included with a median age of 63 years [53.5; 71.1], BMI of 26.6 kg/m2 [22.8; 31.3], SAPS II score of 43 [31; 58], and ICU length of stay of 9 days [6; 15]. Malnutrition was observed in 142 (24.9%) patients. During the 1-year follow-up after discharge, 96 (18.5%) patients died. After adjustment, a low HG test score (aOR = 1.44 [1.11; 1.89], p = 0.01) was associated with 1-year mortality. Patients with low HG score, malnutrition, and Albuminemia <30 g/L had a one-year death rate of 41.4%. Conversely, patients with none of these parameters had a 1-year death rate of 4.1%.

CONCLUSION

BIA to assess FFMI, HG and albuminemia at the end of ICU stay could be used to predict 1-year mortality. Their ability to identify patients eligible for a structured recovery program could be studied.

Prior physical illness predicts death better than acute physiological derangement on intensive care unit admission in COVID-19: A Swedish registry study

COVID-19 is associated with prolonged intensive care unit (ICU) stay and considerable mortality. The onset of persistent critical illness, defined as when prior illness predicts death better than acute physiological derangement, has not been studied in COVID-19. This national cohort study based on the Swedish Intensive Care Registry (SIR) included all patients admitted to a Swedish ICU due to COVID-19 from 6 March 2020 to 9 November 2021. Simplified Acute Physiology Score-3 (SAPS3) Box 1 was used as a measure of prior illness and Box 3 as a measure of acute derangement to evaluate the onset and importance of persistent critical illness in COVID-19. To compare predictive capacity, the area under receiver operating characteristic (AUC) of SAPS3 and its constituent Box 1 and 3 was calculated for 30-day mortality. In 7 969 patients, of which 1 878 (23.6%) died within 30 days of ICU admission, the complete SAPS3 score had acceptable discrimination: AUC 0.75 (95% CI 0.74 to 0.76) but showed under prediction in low-risk patients and over prediction in high-risk patients. SAPS3 Box 1 showed markedly better discrimination than Box 3 (AUC 0.74 vs 0.65, P<0,0001). Using custom logistic models, the difference in predictive performance of prior and acute illness was validated, AUC 0.76 vs AUC 0.69, p<0.0001. Prior physical illness predicts death in COVID-19 better than acute physiological derangement during ICU stay, and the whole SAPS3 score is not significantly better than just prior illness. The results suggests that COVID-19 may exhibit similarities to persistent critical illness immediately from ICU admission, potentially because of long median ICU length-of-stay. Alternatively, the variables in the acute physiological derangement model may not adequately capture the severity of illness in COVID-19.

The Good, the Bad, and the Serum Creatinine: Exploring the Effect of Muscle Mass and Nutrition

Muscle wasting (sarcopenia) is one of the hallmarks of critical illness. Patients admitted to intensive care unit develop sarcopenia through increased protein catabolism, a decrease in protein syntheses, or both. Among the factors known to promote wasting are chronic inflammation and cytokine imbalance, insulin resistance, hypermetabolism, and malnutrition. Moreover, muscle wasting, known to develop in chronic kidney disease patients, is a harmful consequence of numerous complications associated with deteriorated renal function. Plenty of published data suggest that serum creatinine (SCr) reflects increased kidney damage and is also related to body weight. Based on the concept that urea and creatinine are nitrogenous end products of metabolism, the urea:creatinine ratio (UCR) could be applied but with limited clinical usability in case of kidney damage, hypovolemia, excessive, or protein intake, where UCR can be high and independent of catabolism. Recent data suggest that the sarcopenia index should be considered an alternative to serum creatinine. It is more reliable in estimating muscle mass than SCr. However, the optimal biomarker of catabolism is still an unresolved issue. The SCr is not a promising biomarker for renal function and muscle mass based on the influence of several factors. The present review highlights recent findings on the limits of SCr as a surrogate marker of renal function and the assessment modalities of nutritional status and muscle mass measurements.

Comparison of Cystatin C and Creatinine in the Assessment of Measured Kidney Function during Critical Illness

BACKGROUND

Incomplete recovery of kidney function is an important adverse outcome in survivors of critical illness. However, unlike eGFR creatinine, eGFR cystatin C is not confounded by muscle loss and may improve identification of persistent kidney dysfunction.

METHODS

To assess kidney function during prolonged critical illness, we enrolled 38 mechanically ventilated patients with an expected length of stay of >72 hours near admission to intensive care unit (ICU) in a single academic medical center. We assessed sequential kidney function using creatinine, cystatin C, and iohexol clearance measurements. The primary outcome was difference between eGFR creatinine and eGFR cystatin C at ICU discharge using Bayesian regression modeling. We simultaneously measured muscle mass by ultrasound of the rectus femoris to assess the confounding effect on serum creatinine generation.

RESULTS

Longer length of ICU stay was associated with greater difference between eGFR creatinine and eGFR cystatin C at a predicted rate of 2 ml/min per 1.73 m 2 per day (95% confidence interval [CI], 1 to 2). By ICU discharge, the posterior mean difference between creatinine and cystatin C eGFR was 33 ml/min per 1.73 m 2 (95% credible interval [CrI], 24 to 42). In 27 patients with iohexol clearance measured close to ICU discharge, eGFR creatinine was on average two-fold greater than the iohexol gold standard, and posterior mean difference was 59 ml/min per 1.73 m 2 (95% CrI, 49 to 69). The posterior mean for eGFR cystatin C suggested a 22 ml/min per 1.73 m 2 (95% CrI, 13 to 31) overestimation of measured GFR. Each day in ICU resulted in a predicted 2% (95% CI, 1% to 3%) decrease in muscle area. Change in creatinine-to-cystatin C ratio showed good longitudinal, repeated measures correlation with muscle loss, R =0.61 (95% CI, 0.50 to 0.72).

CONCLUSIONS

eGFR creatinine systematically overestimated kidney function after prolonged critical illness. Cystatin C better estimated true kidney function because it seemed unaffected by the muscle loss from prolonged critical illness.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Skeletal Muscle Wasting and Renal Dysfunction After Critical Illness Trauma - Outcomes Study (KRATOS), NCT03736005 .

Subphenotyping heterogeneous patients with chronic critical illness to guide individualised fluid balance treatment using machine learning: a retrospective cohort study

Background

The great heterogeneity of patients with chronic critical illness (CCI) leads to difficulty for intensive care unit (ICU) management. Identifying subphenotypes could assist in individualized care, which has not yet been explored. In this study, we aim to identify the subphenotypes of patients with CCI and reveal the heterogeneous treatment effect of fluid balance for them.

Methods

In this retrospective study, we defined CCI as an ICU length of stay over 14 days and coexists with persistent organ dysfunction (cardiovascular Sequential Organ Failure Assessment (SOFA) score ≥1 or score in any other organ system ≥2) at Day 14. Data from five electronic healthcare record datasets covering geographically distinct populations (the US, Europe, and China) were studied. These five datasets include (1) subset of Derivation (MIMIC-IV v1.0, US) cohort (2008-2019); (2) subset Derivation (MIMIC-III v1.4 'CareVue', US) cohort (2001-2008); (3) Validation I (eICU-CRD, US) cohort (2014-2015); (4) Validation II (AmsterdamUMCdb/AUMC, Euro) cohort (2003-2016); (5) Validation III (Jinling, CN) cohort (2017-2021). Patients who meet the criteria of CCI in their first ICU admission period were included in this study. Patients with age over 89 or under 18 years old were excluded. Three unsupervised clustering algorithms were employed independently for phenotypes derivation and validation. Extreme Gradient Boosting (XGBoost) was used for phenotype classifier construction. A parametric G-formula model was applied to estimate the cumulative risk under different daily fluid management strategies in different subphenotypes of ICU mortality.

Findings

We identified four subphenotypes as Phenotype A, B, C, and D in a total of 8145 patients from three countries. Phenotype A is the mildest and youngest subgroup; Phenotype B is the most common group, of whom patients showed the oldest age, significant acid-base abnormality, and low white blood cell count; Patients with Phenotype C have hypernatremia, hyperchloremia, and hypercatabolic status; and in Phenotype D, patients accompany with the most severe multiple organ failure. An easy-to-use classifier showed good effectiveness. Phenotype characteristics showed robustness across all cohorts. The beneficial fluid balance threshold intervals of subphenotypes were different.

Interpretation

We identified four novel phenotypes that revealed the different patterns and significant heterogeneous treatment effects of fluid therapy within patients with CCI. A prospective study is needed to validate our findings, which could inform clinical practice and guide future research on individualized care.

Funding

This study was funded by 333 High Level Talents Training Project of Jiangsu Province (BRA2019011), General Program of Medical Research from the Jiangsu Commission of Health (M2020052), and Key Research and Development Program of Jiangsu Province (BE2022823).

Timing and burden of persistent critical illnessin UK intensive care units: An observational cohort study

Background

Persistent critical illness is a recognisable clinical syndrome defined conceptually as when the patient's reason for being in the intensive care unit (ICU) is more related to their ongoing critical illness than their original reason for admission. Our objectives were: (1) to assess the day in ICU on which chronic factors (e.g., age, gender and comorbidities) were more predictive of survival than acute factors (e.g. admission diagnosis, physiological derangements) measured on the day of admission; (2) to assess the consistency of this finding across major patient subgroups and over time and (3) to compare case mix characteristics and outcomes for patients determined to develop persistent critical illness (based on ICU length of stay) with other patients.

Methods

Observational cohort study using a high-quality clinical database from the national clinical audit of adult critical care. 217 adult ICUs in England, Wales and Northern Ireland. 835,946 adult patients admitted to participating ICUs between 1 April 2009 and 31 March 2016. The main outcome measure was mortality at discharge from acute hospital.

Results

We fitted two statistical models ('chronic' and 'acute') and updated these based upon patients with an ICU length of stay of at least 1, 2, etc., up to 28 days. The discrimination of the chronic model first exceeded that of the acute model on day 11. Patients with longer stays (>10 days) comprised 9% of admissions but used 45% of ICU bed-days. After a mean ICU length of stay of 22 days and a subsequent 28 days in hospital, 30% died.

Conclusions

Persistent critical illness is commonly encountered in clinical practice and is associated with increased healthcare utilisation and adverse outcomes. Improvements in our understanding of the longer term outcomes and in the development of tools to aid prognostication are urgently required - for humane as well as health economic reasons.

Biological signatures and prediction of an immunosuppressive status-persistent critical illness-among orthopedic trauma patients using machine learning techniques

BACKGROUND

Persistent critical illness (PerCI) is an immunosuppressive status. The underlying pathophysiology driving PerCI remains incompletely understood. The objectives of the study were to identify the biological signature of PerCI development, and to construct a reliable prediction model for patients who had suffered orthopedic trauma using machine learning techniques.

METHODS

This study enrolled 1257 patients from the Medical Information Mart for Intensive Care III (MIMIC-III) database. Lymphocytes were tracked from ICU admission to more than 20 days following admission to examine the dynamic changes over time. Over 40 possible variables were gathered for investigation. Patients were split 80:20 at random into a training cohort (n=1035) and an internal validation cohort (n=222). Four machine learning algorithms, including random forest, gradient boosting machine, decision tree, and support vector machine, and a logistic regression technique were utilized to train and optimize models using data from the training cohort. Patients in the internal validation cohort were used to validate models, and the optimal one was chosen. Patients from two large teaching hospitals were used for external validation (n=113). The key metrics that used to assess the prediction performance of models mainly included discrimination, calibration, and clinical usefulness. To encourage clinical application based on the optimal machine learning-based model, a web-based calculator was developed.

RESULTS

16.0% (201/1257) of all patients had PerCI in the MIMIC-III database. The means of lymphocytes (%) were consistently below the normal reference range across the time among PerCI patients (around 10.0%), whereas in patients without PerCI, the number of lymphocytes continued to increase and began to be in normal range on day 10 following ICU admission. Subgroup analysis demonstrated that patients with PerCI were in a more serious health condition at admission since those patients had worse nutritional status, more electrolyte imbalance and infection-related comorbidities, and more severe illness scores. Eight variables, including albumin, serum calcium, red cell volume distributing width (RDW), blood pH, heart rate, respiratory failure, pneumonia, and the Sepsis-related Organ Failure Assessment (SOFA) score, were significantly associated with PerCI, according to the least absolute shrinkage and selection operator (LASSO) logistic regression model combined with the 10-fold cross-validation. These variables were all included in the modelling. In comparison to other algorithms, the random forest had the optimal prediction ability with the highest area under receiver operating characteristic (AUROC) (0.823, 95% CI: 0.757-0.889), highest Youden index (1.571), and lowest Brier score (0.107). The AUROC in the external validation cohort was also up to 0.800 (95% CI: 0.688-0.912). Based on the risk stratification system, patients in the high-risk group had a 10.0-time greater chance of developing PerCI than those in the low-risk group. A web-based calculator was available at https://starxueshu-perci-prediction-main-9k8eof.streamlitapp.com/.

CONCLUSIONS

Patients with PerCI typically remain in an immunosuppressive status, but those without PerCI gradually regain normal immunity. The dynamic changes of lymphocytes can be a reliable biomarker for PerCI. This work developed a reliable model that may be helpful in improving early diagnosis and targeted intervention of PerCI. Beneficial interventions, such as improving nutritional status and immunity, maintaining electrolyte and acid-base balance, curbing infection, and promoting respiratory recovery, are early warranted to prevent the onset of PerCI, especially among patients in the high-risk group and those with a continuously low level of lymphocytes.

Acquisition of new medical devices among the persistently critically ill: A retrospective cohort study in the Veterans Affairs

Patients who develop persistent critical illness remain in the ICU predominately because they develop new late-onset organ failure(s), which may render them at risk of acquiring a new medical device. The epidemiology and short-term outcomes of patients with persistent critical illness who acquire a new medical device are unknown. We retrospectively studied a cohort admitted to the Veterans Affairs (VA) ICUs from 2014 to 2019. Persistent critical illness was defined as an ICU length of stay of at least 14 days. Receipt of new devices was defined as acquisition of a new tracheostomy, feeding tube (including gastrostomy and jejunostomy tubes), implantable cardiac device, or ostomy. Logistic regression models were fit to identify patient factors associated with the acquisition of each new medical device. Among hospitalized survivors, 90-day posthospitalization discharge location and mortality were identified. From 2014 to 2019, there were 13,184 ICU hospitalizations in the VA which developed persistent critical illness. In total, 30.4% of patients (N = 3998/13,184) acquired at least 1 medical device during their persistent critical illness period. Patients with an initial higher severity of illness and prolonged hospital stay preICU admission had higher odds of acquiring each medical device. Among patients who survived their hospitalization, discharge location and mortality did not significantly differ among those who acquired a new medical device as compared to those who did not. Less than one-third of patients with persistent critical illness acquire a new medical device and no significant difference in short-term outcomes was identified. Future work is needed to understand if the acquisition of new medical devices is contributing to the development of persistent critical illness.

Prevalence, characteristics, and longer-term outcomes of patients with persistent critical illness attributable to COVID-19 in Scotland: a national cohort study

BACKGROUND

Patients with COVID-19 can require critical care for prolonged periods. Patients with persistent critical Illness can have complex recovery trajectories, but this has not been studied for patients with COVID-19. We examined the prevalence, risk factors, and long-term outcomes of critically ill patients with COVID-19 and persistent critical illness.

METHODS

This was a national cohort study of all adults admitted to Scottish critical care units with COVID-19 from March 1, 2020 to September 4, 20. Persistent critical illness was defined as a critical care length of stay (LOS) of ≥10 days. Outcomes included 1-yr mortality and hospital readmission after critical care discharge. Fine and Gray competing risk analysis was used to identify factors associated with persistent critical Illness with death as a competing risk.

RESULTS

A total of 2236 patients with COVID-19 were admitted to critical care; 1045 patients were identified as developing persistent critical Illness, comprising 46.7% of the cohort but using 80.6% of bed-days. Patients with persistent critical illness used more organ support, had longer post-critical care LOS, and longer total hospital LOS. Persistent critical illness was not significantly associated with long-term mortality or hospital readmission. Risk factors associated with increased hazard of persistent critical illness included age, illness severity, organ support on admission, and fewer comorbidities.

CONCLUSIONS

Almost half of all patients with COVID-19 admitted to critical care developed persistent critical illness, with high resource use in critical care and beyond. However, persistent critical illness was not associated with significantly worse long-term outcomes compared with patients who were critically ill for shorter periods.

Chronic critical illness in polytrauma. Results of the Spanish trauma in ICU registry

PURPOSE

Chronic critical illness after trauma injury has not been fully evaluated, and there is little evidence in this regard. We aim to describe the prevalence and risk factors of chronic critical illness (CCI) in trauma patients admitted to the intensive care unit.

MATERIAL AND METHODS

Retrospective observational multicenter study (Spanish Registry of Trauma in ICU (RETRAUCI)). Period March 2015 to December 2019. Trauma patients admitted to the ICU, who survived the first 48 h, were included. Chronic critical illness (CCI) was considered as the need for mechanical ventilation for a period greater than 14 days and/or placement of a tracheostomy. The main outcomes measures were prevalence and risk factors of CCI after trauma.

RESULTS

1290/9213 (14%) patients developed CCI. These patients were older (51.2 ± 19.4 vs 49 ± 18.9); p < .01) and predominantly male (79.9%). They presented a higher proportion of infectious complications (81.3% vs 12.7%; p < .01) and multiple organ dysfunction syndrome (MODS) (27.02% vs 5.19%; p < .01). CCI patients required longer stays in the ICU and had higher ICU and overall in-hospital mortality. Age, injury severity score, head injury, infectious complications, and development of MODS were independent predictors of CCI.

CONCLUSION

CCI in trauma is a prevalent entity in our series. Early identification could facilitate specific interventions to change the trajectory of this process.

Impact of frailty on persistent critical illness: a population-based cohort study

PURPOSE

Acute illness severity predicts mortality in intensive care unit (ICU) patients, however, its predictive value decreases over time in ICU. Typically after 10 days, pre-ICU (antecedent) characteristics become more predictive of mortality, defining the onset of persistent critical illness (PerCI). How patient frailty affects development and death from PerCI is unknown.

METHODS

We conducted a secondary analysis of data from a prospective binational cohort study including 269,785 critically ill adults from 168 ICUs in Australia and New Zealand, investigating whether frailty measured with the Clinical Frailty Scale (CFS) changes the timing of onset and risk of developing PerCI and of subsequent in-hospital mortality. We assessed associations between frailty (CFS ≥ 5) and mortality prediction using logistic regression and area under the receiver operating characteristics (AUROC) curves.

RESULTS

2190 of 50,814 (4.3%) patients with frailty (CFS ≥ 5) versus 6624 of 218,971 (3%) patients without frailty (CFS ≤ 4) developed PerCI (P < 0.001). Among patients with PerCI, 669 of 2190 (30.5%) with frailty and 1194 of 6624 without frailty (18%) died in hospital (P < 0.001). The time point defining PerCI onset did not vary with frailty degree; however, with increasing length of ICU stay, inclusion of frailty progressively improved mortality discrimination (0.1% AUROC improvement on ICU day one versus 3.6% on ICU day 17).

CONCLUSION

Compared to patients without frailty, those with frailty have a higher chance of developing and dying from PerCI. Moreover the importance of frailty as a predictor of mortality increases with ICU length of stay. Future work should explore incorporation of frailty in prognostic models, particularly for long-staying patients.

Catabolism in Critical Illness

OBJECTIVES

Ongoing risk of death and poor functional outcomes are important consequences of prolonged critical illness. Characterizing the catabolic phenotype of prolonged critical illness could illuminate biological processes and inform strategies to attenuate catabolism. We aimed to examine if urea-to-creatinine ratio, a catabolic signature of prolonged critical illness, was associated with mortality after the first week of ICU stay.

DESIGN

Reanalysis of multicenter randomized trial of glutamine supplementation in critical illness (REducing Deaths due to OXidative Stress [REDOXS]).

SETTING

Multiple adult ICUs.

PATIENTS

Adult patients admitted to ICU with two or more organ failures related to their acute illness and surviving to day 7.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The association between time-varying urea-to-creatinine ratio and 30-day mortality was tested using Bayesian joint models adjusted for prespecified-covariates (age, kidney replacement therapy, baseline Sequential Organ Failure Assessment, dietary protein [g/kg/d], kidney dysfunction, and glutamine-randomization). From 1,021 patients surviving to day 7, 166 (16.3%) died by day 30. After adjustment in a joint model, a higher time-varying urea-to-creatinine ratio was associated with increased mortality (hazard ratio [HR], 2.15; 95% credible interval, 1.66-2.82, for a two-fold greater urea-to-creatinine ratio). This association persisted throughout the 30-day follow-up. Mediation analysis was performed to explore urea-to-creatinine ratio as a mediator-variable for the increased risk of death reported in REDOXS when randomized to glutamine, an exogenous nitrogen load. Urea-to-creatinine ratio closest to day 7 was estimated to mediate the risk of death associated with randomization to glutamine supplementation (HR, 1.20; 95% CI, 1.04-1.38; p = 0.014), with no evidence of a direct effect of glutamine (HR, 0.90; 95% CI, 0.62-1.30; p = 0.566).

CONCLUSIONS

The catabolic phenotype measured by increased urea-to-creatinine ratio is associated with increased risk of death during prolonged ICU stay and signals the deleterious effects of glutamine administration in the REDOXS study. Urea-to-creatinine ratio is a promising catabolic signature and potential interventional target.

Chronic Critical Illness in Patients with COVID-19: Characteristics and Outcome of Prolonged Intensive Care Therapy

The spread of SARS-CoV-2 caused a worldwide healthcare threat. High critical care admission rates related to Coronavirus Disease 2019 (COVID-19) respiratory failure were observed. Medical advances helped increase the number of patients surviving the acute critical illness. However, some patients require prolonged critical care. Data on the outcome of patients with a chronic critical illness (CCI) are scarce. Single-center retrospective study including all adult critically ill patients with confirmed COVID-19 treated at the Department of Intensive Care Medicine at the University Medical Center Hamburg-Eppendorf, Germany, between 1 March 2020 and 8 August 2021. We identified 304 critically ill patients with COVID-19 during the study period. Of those, 55% (n = 167) had an ICU stay ≥21 days and were defined as chronic critical illness, and 45% (n = 137) had an ICU stay <21 days. Age, sex and BMI were distributed equally between both groups. Patients with CCI had a higher median SAPS II (CCI: 39.5 vs. no-CCI: 38 points, p = 0.140) and SOFA score (10 vs. 6, p < 0.001) on admission. Seventy-three per cent (n = 223) of patients required invasive mechanical ventilation (MV) (86% vs. 58%; p < 0.001). The median duration of MV was 30 (17-49) days and 7 (4-12) days in patients with and without CCI, respectively (p < 0.001). The regression analysis identified ARDS (OR 3.238, 95% CI 1.827-5.740, p < 0.001) and referral from another ICU (OR 2.097, 95% CI 1.203-3.654, p = 0.009) as factors significantly associated with new-onset of CCI. Overall, we observed an ICU mortality of 38% (n = 115) in the study cohort. In patients with CCI we observed an ICU mortality of 28% (n = 46) compared to 50% (n = 69) in patients without CCI (p < 0.001). The 90-day mortality was 28% (n = 46) compared to 50% (n = 70), respectively (p < 0.001). More than half of critically ill patients with COVID-19 suffer from CCI. Short and long-term survival rates in patients with CCI were high compared to patients without CCI, and prolonged therapy should not be withheld when resources permit prolonged therapy.

Outcomes of prolonged intensive care and rehabilitation at a specialized multidisciplinary center in Sweden

BACKGROUND

Specialized clinics may improve the outcome for patients with prolonged intensive care stays. Admission may depend on diagnosis, need of respiratory support and more. We report the results from a Swedish specialized center with a multidisciplinary team approach to continued intensive care and simultaneous rehabilitation regardless of patients' primary diagnosis or ventilator need.

METHODS

All patients admitted and discharged from 2015 to 2018 were included. Demographics, diagnoses, ventilatory support requirement, discharge destination and survival were retrieved from the center´s quality registry.

RESULTS

A total of 181 patients, mean age 61 ± 16 years, 64% men, were analyzed. A neurological diagnosis was the cause for hospitalization in 46% of patients. Of the 55 patients admitted to the center for weaning from mechanical ventilation, 89% were successfully weaned within a median of 25 (interquartile range (IQR) 16-45) days. Decannulation was intended in 117 patients of which 90% were successful within a median of 25 (IQR 13-43) days. Readmission to intensive care was 4%. Most patients were discharged to their home or to rehabilitation clinics with a lower level of care. In-clinic mortality was 3%. Survival beyond 1 and 2 years after discharge was 79% and 70%, respectively.

CONCLUSION

Patients with prolonged intensive care and complex medical needs treated at a specialized center in Sweden had weaning and decannulation rates comparable to or better than previously reported. Mortality was low, and most patients were discharged home or for further rehabilitation. This was achieved with a multidisciplinary team approach to continued intensive care and simultaneous rehabilitation.

Specific nutritional and metabolic characteristics of COVID‐19 persistent critically ill patients

Background

Little is known about metabolic and nutrition characteristics of patients with coronavirus disease 2019 (COVID‐19) and persistent critical illness. We aimed to compare those characteristics in patients with PCI and COVID‐19 and patients without COVID‐19 infection (non‐CO)—primarily, their energy balance.

Methods

This is a prospective observational study including two consecutive cohorts, defined as needing intubation for >10 days. We collected demographic data, severity scores, nutrition variables, length of stay, and mortality.

Results

Altogether, 104 patients (52 per group) were included (59 ± 14 years old [mean ± SD], 75% men) between July 2019 and May 2020. SAPSII, Nutrition Risk Screening (NRS) score, proportion of obese patients, duration of intubation (18.2 ± 11.7 days), and mortality rates were similar. Patients with COVID‐19 (vs non‐CO) had lower SOFA scores (P = 0.013) and more frequently needed prone position (P < 0.0001) and neuromuscular blockade (P < 0.0001): lengths of ICU (P = 0.03) and hospital stays were shorter (P < 0.0001). Prescribed energy targets were below those of the ICU protocol. The energy balance of patients with COVID‐19 was significantly more negative after day 10. Enteral nutrition (EN) started earlier (P < 0.0001). During the first 10 days, COVID‐19 patients received more lipid (propofol sedation) and less protein. Higher admission C‐reactive protein (P = 0.002) decreased faster (P < 0.001). Whereas intestinal function was characterized by constipation in both groups during the first 10 days, diarrhea was less common in patients with COVID‐19 thereafter.

Conclusion

Compared with non‐CO patients, COVID‐19 patients were not more obese, had lower SOFA scores, and were fed more rapidly with EN, because of a more normal gastrointestinal function possibly due to fewer non–respiratory organ failures: their energy balances were more negative after the first 10 days. Propofol sedation reduced protein delivery.

SPLIT ENZ: Survivorship of Patients post Long Intensive care stay, Exploration/Experience in a New Zealand cohort (A mixed methods study protocol) (Preprint)

Background

Post Intensive Care Syndrome (PICS) was defined by the Society of Critical Care Medicine in 2012 with subsequent international research highlighting poor long-term outcomes; reduced quality of life; and impairments, for survivors of critical illness. To date, there has been no published research on the long-term outcomes of survivors of critical illness in New Zealand.

Objective

The aim of this study is to explore long-term outcomes after critical illness in New Zealand. The primary objectives are to describe and quantify symptoms and disability, explore possible risk factors, and to identify unmet needs in survivors of critical illness.

Methods

This will be a mixed methods study with 2 components. First, a prospective cohort study of approximately 100 participants with critical illness will be followed up at 1, 6, and 12 months after hospital discharge. The primary outcome will be disability assessed using the World Health Organization Disability Assessment Scale 2.0. Secondary outcomes will focus on mental health using the Hospital Anxiety and Depression Scale and the Impact of Events Scale-revised, cognitive function using the Montreal Cognitive Assessment (Montreal Cognitive Assessment–BLIND), and health-related quality of life using the European Quality of Life-Five Dimension-Five Level. The second element of the study will use qualitative grounded theory methods to explore participants experiences of recovery and highlight unmet needs.

Results

This study was approved by the New Zealand Northern A Health and Disability Ethics Committee on August 16, 2021 (21/NTA/107), and has been registered with the Australian New Zealand Clinical Trials Registry on October 5, 2021. SPLIT ENZ is due to start recruitment in early 2022, aiming to enroll 125 patients over 2 years. Data collection is estimated to be completed by 2024-2025 and will be published once all data are available for reporting.

Conclusions

Although international research has identified the prevalence of PICS and the extent of disability in survivors of critical illness, there is no published research in New Zealand. Research in this field is particularly pressing in the context of COVID-19, an illness that may include PICS in its sequelae.

Trial Registration

Australian New Zealand Clinical Trials Registry ACTRN1262100133588; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=382566&showOriginal=true&isReview=true

International Registered Report Identifier (IRRID)

PRR1-10.2196/35936

Improving nutritional therapy of persistent critically ill patients by organisational measures: A before and after study

BACKGROUND & AIMS

Critically ill patients requiring prolonged intensive care (ICU) treatment are at high risk of malnutrition, which latter contributes to worsening outcome. Having observed that despite the presence of a nutrition protocol and dieticians, the patients with persistent critical illness (PCI) had been underfed during their ICU stay and particularly during the first 10 days, the aim was to analyse the impact of the organisational changes that were proposed to prevent the observed malnutrition.

METHODS

Before (Period A) and after (Period B) study enrolling critically ill patients consecutively admitted, requiring >10 days of ICU treatment. The intervention consisted in increasing the early morning interactions between dieticians, nurses, and physicians, while modifying the computer visualisation of the dietician proposals. The primary endpoint was a reduction in the cumulative energy balance in period B. The ICU stay was divided in early ICU stay (first 10 days) and late ICU stay (day 11 to day 30). Other variables: protein, glucose, and prealbumin.

RESULTS

Altogether, 205 patients (150 and 55 in period A and B respectively) were enrolled in the PCI program. Patient characteristics were similar over both periods except for lower SAPSII score in period B. There was no difference in nutritional pattern in the first 10 days between periods. The cumulate energy balance was less negative from day 11-30 in period B than in A (-884 vs -1566 kcal; p = 0.033). There was a one-day reduction in the median duration of fasting in period B (p < 0.0001). Overall compliance with nutrition protocol improved in period B with an earlier first indirect calorimetry (p = 0.003) and prealbumin measurement (p < 0.001), the latter increasing significantly more during ICU stay.

CONCLUSION

Organizational changes that allowed an early identification of patients at nutritional risk, an increased targeted dieticians intervention and a better inter-disciplinary work was associated with a reduction in undue fasting, and significantly improved energy balances.

The long-term ICU patient: Which definition?

AIMS AND OBJECTIVES

To offer a review of the differing terminologies used by clinicians and researchers to describe the long-term intensive care unit (ICU) patient and the underlying propositions that align with this terminology.

BACKGROUND

Ongoing medical and technological advances in emergency and intensive care have resulted in improved survival of critically ill patients in recent decades. In addition, these advancements have also resulted in improved survival of complex critically ill patients who progress to a trajectory of prolonged critical illness, having protracted stays in the ICU. There is great variability in terminology used to define the long-term ICU patient. This lack of a common definition for long-term ICU patients is problematic, increasing their vulnerability and risk of care not being centred about their unique needs.

DESIGN

In this discursive article, we explore the terminology used to define the long-term ICU patient. An initial broad search of the literature across four electronic databases was conducted to identify common terminology used to define the long-term ICU patient. From here, seven definitions were identified and chosen for inclusion in the review as they meet inclusion criteria and clearly described a group of patients who have an extended ICU stay. The seven selected terms are as follows: prolonged mechanical ventilation; failure to wean; insertion of tracheostomy; chronically critically ill; persistent critical illness; persistent inflammatory-immunosuppressive and catabolic syndrome; and frailty. Following this a focused review of the literature with the selected terms was conducted to explore in greater detail the terminology.

DISCUSSION

The lack of clear definition for this patient group can potentiate their care needs being unmet. Acknowledgement of the need to clearly define this patient group is the first step to improve outcomes. Nursing is well positioned to recognise the different terminologies use to describe this group of patients and implement care to suit their unique clinical characteristics.

CONCLUSION AND RELEVANCE TO CLINICAL PRACTICE

Recognition and standardisation of these terms are an important priority to pave the way to improve care pathways and outcomes for this group of patients and their family.

Identification of the toxic threshold of 3-hydroxybutyrate-sodium supplementation in septic mice

BACKGROUND

In septic mice, supplementing parenteral nutrition with 150 mg/day 3-hydroxybutyrate-sodium-salt (3HB-Na) has previously shown to prevent muscle weakness without obvious toxicity. The main objective of this study was to identify the toxic threshold of 3HB-Na supplementation in septic mice, prior to translation of this promising intervention to human use.

METHODS

In a centrally-catheterized, antibiotic-treated, fluid-resuscitated, parenterally fed mouse model of prolonged sepsis, we compared with placebo the effects of stepwise escalating doses starting from 150 mg/day 3HB-Na on illness severity and mortality (n = 103). For 5-day survivors, also the impact on ex-vivo-measured muscle force, blood electrolytes, and markers of vital organ inflammation/damage was documented.

RESULTS

By doubling the reference dose of 150 mg/day to 300 mg/day 3HB-Na, illness severity scores doubled (p = 0.004) and mortality increased from 30.4 to 87.5 % (p = 0.002). De-escalating this dose to 225 mg still increased mortality (p ≤ 0.03) and reducing the dose to 180 mg/day still increased illness severity (p ≤ 0.04). Doses of 180 mg/day and higher caused more pronounced metabolic alkalosis and hypernatremia (p ≤ 0.04) and increased markers of kidney damage (p ≤ 0.05). Doses of 225 mg/day 3HB-Na and higher caused dehydration of brain and lungs (p ≤ 0.05) and increased markers of hippocampal neuronal damage and inflammation (p ≤ 0.02). Among survivors, 150 mg/day and 180 mg/day increased muscle force compared with placebo (p ≤ 0.05) up to healthy control levels (p ≥ 0.3).

CONCLUSIONS

This study indicates that 150 mg/day 3HB-Na supplementation prevented sepsis-induced muscle weakness in mice. However, this dose appeared maximally effective though close to the toxic threshold, possibly in part explained by excessive Na+ intake with 3HB-Na. Although lower doses were not tested and thus might still hold therapeutic potential, the current results point towards a low toxic threshold for the clinical use of ketone salts in human critically ill patients. Whether 3HB-esters are equally effective and less toxic should be investigated.

Talking to multi-morbid patients about critical illness: an evolving conversation

Conversations around critical illness outcomes and benefits from intensive care unit (ICU) treatment have begun to shift away from binary discussions on living versus dying. Increasingly, the reality of survival with functional impairment versus survival with a late death is being recognised as relevant to patients. Most ICU admissions are associated with new functional and cognitive disabilities that are significant and long lasting. When discussing outcomes, clinicians rightly focus on patients' wishes and the quality of life (QoL) that they would find acceptable. However, patients' views may encompass differing views on acceptable QoL post-critical illness, not necessarily reflected in standard conversations. Maintaining independence is a greater priority to patients than simple survival. QoL post-critical illness determines judgments on the benefits of ICU support but translating this into clinical practice risks potential conflation of health outcomes and QoL. This article discusses the concept of response shift and the implication for trade-offs between number/length of invasive treatments and change in physical function or death. Conversations need to delineate how health outcomes (e.g. tracheostomy, muscle wasting, etc.) may affect individual outcomes most relevant to the patient and hence impact overall QoL. The research strategy taken to explore decision-making for critically ill patients might benefit from gathering qualitative data, as a complement to quantitative data. Patients, families and doctors are motivated by far wider considerations, and a consultation process should relate to more than the simple likelihood of mortality in a shared decision-making context.

Variation in Pediatric Palliative Care Allocation Among Critically Ill Children in the United States

OBJECTIVES

The objectives are as follows: 1) estimate palliative care consult rates and trends among critically ill children and 2) characterize which children receive palliative care consults, including those meeting previously proposed ICU-specific palliative care screening criteria.

DESIGN

Retrospective cohort.

SETTING

Fifty-two United States children's hospitals participating in the Pediatric Health Information Systems database.

PATIENTS

Hospitalized children with nonneonatal ICU admissions from 2007 to 2018.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was palliative care consultation, as identified by the palliative care International Classification of Disease code. Patient characteristics and outcomes were compared between those with and without palliative care. We used a mixed-effects multivariable model to estimate the independent association between the palliative care and patient characteristics accounting for institution and subject clustering. Hospitalizations were categorized into three mutually exclusive groups for comparative analyses: 1) meeting ICU-specific palliative care criteria, 2) presence of a complex chronic condition not in ICU-specific palliative care criteria, or 3) not meeting ICU-specific palliative care or complex chronic condition criteria. Rates and trends of palliative care consultation were estimated including variation among institutions and variation among subcategories of ICU-specific palliative care criteria. The study cohort included 740,890 subjects with 1,024,666 hospitalizations. About 1.36% of hospitalizations had a palliative care consultation. Palliative care consult was independently associated with older age, female sex, government insurance, inhospital mortality, and ICU-specific palliative care or complex chronic condition criteria. Among the hospitalizations, 30% met ICU-specific palliative care criteria, 40% complex chronic condition criteria, and 30% neither. ICU-specific palliative care patients received more mechanical ventilation and cardiopulmonary resuscitation, had longer hospital and ICU lengths of stay, and had higher inhospital mortality (p < 0.001). Palliative care utilization increased over the study period with considerable variation between the institutions especially in the ICU-specific palliative care cohort and its subgroups.

CONCLUSIONS

Palliative care consultation for critically ill children in the United States is low. Palliative care utilization is increasing but considerable variation exists across institutions, suggesting inequity in palliative care allocation among this vulnerable population. Future studies should evaluate factors influencing allocation of palliative care among critically ill children in the United States and the drivers of differences between the institutional practices.

Long-term outcome of prolonged critical illness: A multicentered study in North Brisbane, Australia

Background

Although critical illness is usually of high acuity and short duration, some patients require prolonged management in intensive care units (ICU) and suffer long-term morbidity and mortality.

Objective

To describe the long-term survival and examine determinants of death among patients with prolonged ICU admission.

Methods

A retrospective cohort of adult Queensland residents admitted to ICUs for 14 days or longer in North Brisbane, Australia was assembled. Comorbid illnesses were classified using the Charlson definitions and all cause case fatality established using statewide vital statistics.

Results

During the study a total of 28,742 adult Queensland residents had first admissions to participating ICUs of which 1,157 (4.0%) had prolonged admissions for two weeks or longer. Patients with prolonged admissions included 645 (55.8%), 243 (21.0%), and 269 (23.3%) with ICU lengths of stay lasting 14–20, 21–27, and ≥28 days, respectively. Although the severity of illness at admission did not vary, pre-existing comorbid illnesses including myocardial infarction, congestive heart failure, kidney disease, and peptic ulcer disease were more frequent whereas cancer, cerebrovascular accidents, and plegia were less frequently observed among patients with increasing ICU lengths of stay lasting 14–20, 21–27, and ≥28 days. The ICU, hospital, 90-day, and one-year all cause case-fatality rates were 12.7%, 18.5%, 20.2%, and 24.9%, respectively, and were not different according to duration of ICU stay. The median duration of observation was 1,037 (interquartile range, 214–1888) days. Although comorbidity, age, and admitting diagnosis were significant, neither ICU duration of stay nor severity of illness at admission were associated with overall survival outcome in a multivariable Cox regression model.

Conclusions

Most patients with prolonged stays in our ICUs are alive at one year post-admission. Older age and previous comorbidities, but not severity of illness or duration of ICU stay, are associated with adverse long-term mortality outcome.

Epidemiology of Chronic Critical Illness in Japan: A Nationwide Inpatient Database Study

OBJECTIVES

The epidemiology of chronic critical illness is not well known. We aimed to estimate the prevalence, mortality, and costs associated with chronic critical illness in Japan.

DESIGN

A nationwide inpatient administrative database study in Japan from April 2011 to March 2018.

SETTING

Six hundred seventy-nine acute-care hospitals with ICU beds in Japan.

PATIENTS

Adult patients who met our definition for chronic critical illness: one of six eligible clinical conditions (prolonged acute mechanical ventilation, tracheotomy, stroke, traumatic brain injury, sepsis, and severe wound) plus at least 8 consecutive days in an ICU.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Among 2,395,016 ICU admissions during the study period, 216,434 (9.0%) met the definition for chronic critical illness. The most common eligible condition was prolonged acute mechanical ventilation (73.9%), followed by sepsis (50.6%), tracheostomy (23.8%), and stroke (22.8%). Overall inhospital mortality was 28.6%. The overall age-specific population prevalence was 42.0 per 100,000. The age-specific population prevalence steadily increased with age, reaching 109.6 per 100,000 in persons aged greater than 85 years. With extrapolation to national estimates in Japan, there were 47,729 chronic critical illness cases in 2011 and the number remained similar at 46,494 cases in 2017. Hospitalization costs increased gradually, rising from U.S.$2.3 billion in 2011 to U.S.$2.7 billion in 2017. Inhospital mortality decreased from 30.6% to 28.2%, whereas the proportion of patients with total/severe dependence increased from 29.6% to 33.2% and the proportion of patients with decreased consciousness at discharge increased from 18.7% to 19.6%.

CONCLUSIONS

Using a nationwide inpatient database in Japan, we found substantial clinical and economic burdens of chronic critical illness in Japan. Chronic critical illness was particularly common in elderly people. Although inhospital mortality of chronic critical illness patients continues to decrease, costs and patients with dependence for activities of daily living or decreased consciousness at discharge are increasing.

Interrater Reliability of the Clinical Frailty Scale by Geriatrician and Intensivist in Patients Admitted to the Intensive Care Unit

Background

The Clinical Frailty Scale (CFS) is a commonly used frailty measure in intensive care unit (ICU) settings. We are interested in the test characteristics, especially interrater reliability, of the CFS in ICU by comparing the scores of intensivists to geriatricians.

Methods

We conducted a prospective cohort study on a convenience sample of newly admitted patients to an ICU in Edmonton, Canada. An intensivist and a resident in Geriatric Medicine (GM) independently assigned a CFS score on 158 adults within 72 hours of admission. A specialist in Geriatric Medicine assigned a CFS score independently of 20 of the 158 patients to assess agreement between the two raters trained in geriatrics. Predictive validity was captured using mortality and length of stay.

Results

Agreement on CFS score was fair for intensivists vs. GM resident (kappa 0.32) and for intensivists vs. GM specialist (0.29), but substantial for GM resident vs. staff (0.79). Despite this, the CFS remained prognostically relevant, regardless of rater background. Frailty (CFS ≥ 5) as assessed by either intensivist or GM resident was a strong predictor of in-hospital mortality (odds ratio [OR] 3.6; 95% CI, 1.6–8.4, p = .003 and OR 3.0; 95% CI 1.3–6.9; p = .01, respectively). Frailty was also positively correlated with age, illness severity measured by APACHE II score, and length of hospital stay.

Conclusions

The interrater reliability of the CFS in ICU settings is fair for intensivists vs. geriatricians.

Assessment of Costs of Avoidable Delays in Intensive Care Unit Discharge

IMPORTANCE

Delays in transfer for discharge-ready patients from the intensive care unit (ICU) are increasingly described and contribute to strained capacity.

OBJECTIVE

To describe the epidemiological features and health care costs attributable to potentially avoidable delays in ICU discharge in a large integrated health care system.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study was performed in 17 adult ICUs in Alberta, Canada, from June 19, 2012, to December 31, 2016. Participants were patients 15 years or older admitted to a study ICU during the study period. Data were analyzed from October 19, 2018, to May 20, 2020.

EXPOSURES

Avoidable time in the ICU, defined as the portion of total ICU patient-days accounted for by avoidable delay in ICU discharge (eg, waiting for a ward bed).

MAIN OUTCOMES AND MEASURES

The primary outcome was health care costs attributable to avoidable time in the ICU. Secondary outcomes were factors associated with avoidable time, in-hospital mortality, and measures of use of health care resources, including the number of hours in the ICU and the number of days of hospitalization. Multilevel mixed multivariable regression was used to assess associations between avoidable time and outcomes.

RESULTS

In total, 28 904 patients (mean [SD] age, 58.3 [16.8] years; 18 030 male [62.4%]) were included. Of these, 19 964 patients (69.1%) had avoidable time during their ICU admission. The median avoidable time per patient was 7.2 (interquartile range, 2.4-27.7) hours. In multivariable analysis, male sex (odds ratio [OR], 0.92; 95% CI, 0.87-0.98), comorbid hemiplegia or paraplegia (OR 1.47; 95% CI, 1.23-1.75), liver disease (OR 1.20; 95% CI, 1.04-1.37), admission Acute Physiology and Chronic Health Evaluation II score (OR, 1.03; 95% CI, 1.02-1.03), surgical status (OR, 0.90; 95% CI, 0.82-0.98), medium community hospital type (OR, 0.12; 95% CI, 0.04-0.32), and admission year (OR, 1.16; 95% CI, 1.13-1.19) were associated with avoidable time. The cumulative avoidable time was 19 373.9 days, with estimated attributable costs of CAD$34 323 522. Avoidable time accounted for 12.8% of total ICU bed-days and 6.4% of total ICU costs. Patients with avoidable time before ICU discharge showed higher unadjusted in-hospital mortality (1115 [5.6%] vs 392 [4.4%]; P < .001); however, in multivariable analysis, avoidable time was associated with reduced in-hospital mortality (adjusted hazard ratio, 0.74; 95% CI, 0.64-0.85). Results were similar in sensitivity analyses.

CONCLUSIONS AND RELEVANCE

In this study, potentially avoidable discharge delay occurred for most patients admitted to ICUs across a large integrated health system and translated into substantial associated health care costs.

Late Vasopressor Administration in Patients in the ICU: A Retrospective Cohort Study

BACKGROUND

Little is known about the prevalence, predictors, and outcomes of late vasopressor administration which evolves after admission to the ICU.

RESEARCH QUESTION

What is the epidemiology of late vasopressor administration in the ICU?

STUDY DESIGN AND METHODS

We retrospectively studied a cohort of veterans admitted to the Veterans Administration ICUs for ≥ 4 days from 2014 to 2017. The timing of vasopressor administration was categorized as early (only within the initial 3 days), late (on day 4 or later and none on day 3), and continuous (within the initial 2 days through at least day 4). Regressions were performed to identify patient factors associated with late vasopressor administration and the timing of vasopressor administration with posthospitalization discharge mortality.

RESULTS

Among the 62,206 hospitalizations with at least 4 ICU days, late vasopressor administration occurred in 5.5% (3,429 of 62,206). Patients with more comorbidities (adjusted OR [aOR], 1.02 per van Walraven point; 95% CI, 1.02-1.03) and worse severity of illness on admission (aOR, 1.01 per percentage point risk of death; 95% CI, 1.01-1.02) were more likely to receive late vasopressor therapy. Nearly 50% of patients started a new antibiotic within 24 h of receiving late vasopressor therapy. One-year mortality after survival to discharge was higher for patients with continuous (adjusted hazard ratio [aHR], 1.48; 95% CI, 1.33-1.65) and late vasopressor administration (aHR, 1.26; 95% CI, 1.15-1.38) compared with only early vasopressor administration.

INTERPRETATION

Late vasopressor administration was modestly associated with comorbidities and admission illness severity. One-year mortality was higher among those who received late vasopressor administration compared with only early vasopressor administration. Research to understand optimization of late vasopressor therapy administration may improve long-term mortality.

Characteristics and predictors of chronic critical illness in the intensive care unit

Objective

To characterize patients with chronic critical illness and identify predictors of development of chronic critical illness.

Methods

Prospective data was collected for 1 year in the intensive care unit of a general hospital in Southern Brazil. Three logistic regression models were constructed to identify factors associated with chronic critical illness.

Results

Among the 574 subjects admitted to the intensive care unit, 200 were submitted to mechanical ventilation. Of these patients, 85 (43.5%) developed chronic critical illness, composing 14.8% of all the patients admitted to the intensive care unit. The regression model that evaluated the association of chronic critical illness with conditions present prior to intensive care unit admission identified chronic renal failure in patients undergoing hemodialysis (OR 3.57; p = 0.04) and a neurological diagnosis at hospital admission (OR 2.25; p = 0.008) as independent factors. In the model that evaluated the association of chronic critical illness with situations that occurred during intensive care unit stay, muscle weakness (OR 2.86; p = 0.01) and pressure ulcers (OR 9.54; p < 0.001) had the strongest associations. In the global multivariate analysis (that assessed previous factors and situations that occurred in the intensive care unit), hospital admission due to neurological diseases (OR 2.61; p = 0.03) and the development of pressure ulcers (OR 9.08; p < 0.001) had the strongest associations.

Conclusion

The incidence of chronic critical illness in this study was similar to that observed in other studies and had a strong association with the diagnosis of neurological diseases at hospital admission and chronic renal failure in patients undergoing hemodialysis, as well as complications developed during hospitalization, such as pressure ulcers and muscle weakness.

Effective Care Practices in Patients Receiving Prolonged Mechanical Ventilation. An Ethnographic Study

Rationale: Patients receiving prolonged mechanical ventilation experience low survival rates and incur high healthcare costs. However, little is known about how to optimally organize and manage their care.Objectives: To identify a set of effective care practices for patients receiving prolonged mechanical ventilation.Methods: We performed a focused ethnographic evaluation at eight long-term acute care hospitals in the United States ranking in either the lowest or highest quartile of risk-adjusted mortality in at least four of the five years between 2007 and 2011.Measurements and Main Results: We conducted 329 hours of direct observation, 196 interviews, and 39 episodes of job shadowing. Data were analyzed using thematic content analysis and a positive-negative deviance approach. We found that high- and low-performing hospitals differed substantially in their approach to care. High-performing hospitals actively promoted interdisciplinary communication and coordination using a range of organizational practices, including factors related to leadership (e.g., leaders who communicate a culture of quality improvement), staffing (e.g., lower nurse-to-patient ratios and ready availability of psychologists and spiritual care providers), care protocols (e.g., specific yet flexible respiratory therapy-driven weaning protocols), team meetings (e.g., interdisciplinary meetings that include direct care providers), and the physical plant (e.g., large workstations that allow groups to interact). These practices were believed to facilitate care that is simultaneously goal directed and responsive to individual patient needs, leading to more successful liberation from mechanical ventilation and improved survival.Conclusions: High-performing long-term acute care hospitals employ several organizational practices that may be helpful in improving care for patients receiving prolonged mechanical ventilation.

The performance of acute versus antecedent patient characteristics for 1-year mortality prediction during intensive care unit admission: a national cohort study

Background

Multiple factors contribute to mortality after ICU, but it is unclear how the predictive value of these factors changes during ICU admission. We aimed to compare the changing performance over time of the acute illness component, antecedent patient characteristics, and ICU length of stay (LOS) in predicting 1-year mortality.

Methods

In this retrospective observational cohort study, the discriminative value of four generalized mixed-effects models was compared for 1-year and hospital mortality. Among patients with increasing ICU LOS, the models included (a) acute illness factors and antecedent patient characteristics combined, (b) acute component only, (c) antecedent patient characteristics only, and (d) ICU LOS. For each analysis, discrimination was measured by area under the receiver operating characteristics curve (AUC), calculated using the bootstrap method. Statistical significance between the models was assessed using the DeLong method (p value < 0.05).

Results

In 400,248 ICU patients observed, hospital mortality was 11.8% and 1-year mortality 21.8%. At ICU admission, the combined model predicted 1-year mortality with an AUC of 0.84 (95% CI 0.84–0.84). When analyzed separately, the acute component progressively lost predictive power. From an ICU admission of at least 3 days, antecedent characteristics significantly exceeded the predictive value of the acute component for 1-year mortality, AUC 0.68 (95% CI 0.68–0.69) versus 0.67 (95% CI 0.67–0.68) (p value < 0.001). For hospital mortality, antecedent characteristics outperformed the acute component from a LOS of at least 7 days, comprising 7.8% of patients and accounting for 52.4% of all bed days. ICU LOS predicted 1-year mortality with an AUC of 0.52 (95% CI 0.51–0.53) and hospital mortality with an AUC of 0.54 (95% CI 0.53–0.55) for patients with a LOS of at least 7 days.

Conclusions

Comparing the predictive value of factors influencing 1-year mortality for patients with increasing ICU LOS, antecedent patient characteristics are more predictive than the acute component for patients with an ICU LOS of at least 3 days. For hospital mortality, antecedent patient characteristics outperform the acute component for patients with an ICU LOS of at least 7 days. After the first week of ICU admission, LOS itself is not predictive of hospital nor 1-year mortality.

Hospital-level variation in the development of persistent critical illness

PURPOSE

Patients with persistent critical illness may account for up to half of all intensive care unit (ICU) bed-days. It is unknown if there is hospital variation in the development of persistent critical illness and if hospital performance affects the incidence of persistent critical illness.

METHODS

This is a retrospective analysis of Veterans admitted to the Veterans Administration (VA) ICUs from 2015 to 2017. Hospital performance was defined by the risk- and reliability-adjusted 30-day mortality. Persistent critical illness was defined as an ICU length of stay of at least 11 days. We used 2-level multilevel logistic regression models to assess variation in risk- and reliability-adjusted probabilities in the development of persistent critical illness.

RESULTS

In the analysis of 100 hospitals which encompassed 153,512 hospitalizations, 4.9% (N = 7640/153,512) developed persistent critical illness. There was variation in the development of persistent critical illness despite controlling for patient characteristics (intraclass correlation: 0.067, 95% CI 0.049-0.091). Hospitals with higher risk- and reliability-adjusted 30-day mortality had higher probabilities of developing persistent critical illness (predicted probability: 0.057, 95% CI 0.051-0.063, p < 0.01) compared to those with lower risk- and reliability-adjusted 30-day mortality (predicted probability: 0.046, 95% CI 0.041-0.051, p < 0.01). The median odds ratio was 1.4 (95% CI 1.33-1.49) implying that, for two patients with the same physiology on admission at two different VA hospitals, the patient admitted to the hospital with higher adjusted mortality would have 40% greater odds of developing persistent critical illness.

CONCLUSION

Hospitals with higher risk- and reliability-adjusted 30-day mortality have a higher probability of developing persistent critical illness. Understanding the drivers of this variation may identify modifiable factors contributing to the development of persistent critical illness.

Timing of Onset, Burden, and Postdischarge Mortality of Persistent Critical Illness in Scotland, 2005-2014: A Retrospective, Population-Based, Observational Study

We aimed to understand the prevalence, timing of onset, resource use, and long-term outcomes of patients who developed persistent critical illness in a national dataset.

Design

Retrospective cohort. Using a physiologic risk adjustment model from ICU admission, we examined the relative ability of acute (related to reason for ICU presentation) and antecedent (demographics, comorbidities) characteristics to discriminate hospital mortality models. Persistent critical illness was defined as the point during an ICU stay when, at the population-level, patients' acute diagnoses and physiologic disturbance are no longer more accurate at discriminating who survives than are baseline demographics and comorbidity. We examined the change across ICU stay in the relative discrimination of those characteristics, and short-term (in-hospital and 30 d after admission) and medium-term (90 d after admission) survival. Finally, we analyzed the changes in the population definition of persistent critical illness over time.

Setting

Patients admitted as level 3 to Scottish ICUs between 2005 and 2014.

Patients

Seventy-two-thousand two-hundred fifty-three adult level 3 ICU admissions in 23 ICUs across Scotland.

Interventions

None.

Measurements and Main Results

The onset of persistent critical illness, occurs at an average of 5.0 days (95% CI, 3.9-6.4 d) across this dataset. The crossing point increased across the decade, by an average of 0.36 days (95% CI, 0.22-0.50 d) per year. In this dataset, 24,425 (33.8%) remained in the ICU long enough to meet this greater than 5-day definition of persistent critical illness. The care of such patients involved 72.3% ICU days used by any level 3 patient; 46.5% of all Scottish ICU bed-days were after day 5. Although rates of 30 days after admission survival rose dramatically during the decade under study, these rates were similar for those with shorter or longer ICU stays, as were the rates of 90-day survival among those who survived at least 30 days.

Conclusions

Persistent critical illness occurred in one in three ICU patients in Scotland. These minority of patients accounted for disproportionate hospital resources but did not have worse 30- or 90-day postadmission survival.

Effect of Intermittent or Continuous Feed on Muscle Wasting in Critical Illness: A Phase 2 Clinical Trial

BACKGROUND

Acute skeletal muscle wasting in critical illness is associated with excess morbidity and mortality. Continuous feeding may suppress muscle protein synthesis as a result of the muscle-full effect, unlike intermittent feeding, which may ameliorate it.

RESEARCH QUESTION

Does intermittent enteral feed decrease muscle wasting compared with continuous feed in critically ill patients?

STUDY DESIGN AND METHODS

In a phase 2 interventional single-blinded randomized controlled trial, 121 mechanically ventilated adult patients with multiorgan failure were recruited following prospective informed consultee assent. They were randomized to the intervention group (intermittent enteral feeding from six 4-hourly feeds per 24 h, n = 62) or control group (standard continuous enteral feeding, n = 59). The primary outcome was 10-day loss of rectus femoris muscle cross-sectional area determined by ultrasound. Secondary outcomes included nutritional target achievements, plasma amino acid concentrations, glycemic control, and physical function milestones.

RESULTS

Muscle loss was similar between arms (-1.1% [95% CI, -6.1% to -4.0%]; P = .676). More intermittently fed patients received 80% or more of target protein (OR, 1.52 [1.16-1.99]; P < .001) and energy (OR, 1.59 [1.21-2.08]; P = .001). Plasma branched-chain amino acid concentrations before and after feeds were similar between arms on trial day 1 (71 μM [44-98 μM]; P = .547) and trial day 10 (239 μM [33-444 μM]; P = .178). During the 10-day intervention period the coefficient of variation for glucose concentrations was higher with intermittent feed (17.84 [18.6-20.4]) vs continuous feed (12.98 [14.0-15.7]; P < .001). However, days with reported hypoglycemia and insulin usage were similar in both groups. Safety profiles, gastric intolerance, physical function milestones, and discharge destinations did not differ between groups.

INTERPRETATION

Intermittent feeding in early critical illness is not shown to preserve muscle mass in this trial despite resulting in a greater achievement of nutritional targets than continuous feeding. However, it is feasible and safe.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT02358512; URL: www.clinicaltrials.gov.

Data initiatives supporting critical care research and quality improvement in Canada: an environmental scan and narrative review

PURPOSE

Collection and analysis of health data are crucial to achieving high-quality clinical care, research, and quality improvement. This review explores existing hospital, regional, provincial and national data platforms in Canada to identify gaps and barriers, and recommend improvements for data science.

SOURCE

The Canadian Critical Care Trials Group and the Canadian Critical Care Translational Biology Group undertook an environmental survey using list-identified names and keywords in PubMed and the grey literature, from the Canadian context. Findings were grouped into sections, corresponding to geography, purpose, and patient sub-group initiatives, using a narrative qualitative approach. Emerging themes, impressions, and recommendations towards improving data initiatives were generated.

PRINCIPAL FINDINGS

In Canada, the Canadian Institute for Health Information Discharge Abstract Database contains high-level clinical data on every adult and child discharged from acute care facilities; however, it does not contain data from Quebec, critical care-specific severity of illness risk-adjustment scores, physiologic data, or data pertaining to medication use. Provincially mandated critical care platforms in four provinces contain more granular data, and can be used to risk adjust and link to within-province data sets; however, no inter-provincial collaborative mechanism exists. There is very limited infrastructure to collect and link biological samples from critically ill patients nationally. Comprehensive international clinical data sets may inform future Canadian initiatives.

CONCLUSION

Clinical and biological data collection among critically ill patients in Canada is not sufficiently coordinated, and lags behind other jurisdictions. An integrated and inclusive critical care data platform is a key clinical and scientific priority in Canada.

Defining persistent critical illness based on growth trajectories in patients with sepsis

BACKGROUND

Persistent critical illness is common in critically ill patients and is associated with vast medical resource use and poor clinical outcomes. This study aimed to define when patients with sepsis would be stabilized and transitioned to persistent critical illness, and whether such transition time varies between latent classes of patients.

METHODS

This was a retrospective cohort study involving sepsis patients in the eICU Collaborative Research Database. Persistent critical illness was defined at the time when acute physiological characteristics were no longer more predictive of in-hospital mortality (i.e., vital status at hospital discharge) than antecedent characteristics. Latent growth mixture modeling was used to identify distinct trajectory classes by using Sequential Organ Failure Assessment score measured during intensive care unit stay as the outcome, and persistent critical illness transition time was explored in each latent class.

RESULTS

The mortality was 16.7% (3828/22,868) in the study cohort. Acute physiological model was no longer more predictive of in-hospital mortality than antecedent characteristics at 15 days after intensive care unit admission in the overall population. Only a minority of the study subjects (n = 643, 2.8%) developed persistent critical illness, but they accounted for 19% (15,834/83,125) and 10% (19,975/198,833) of the total intensive care unit and hospital bed-days, respectively. Five latent classes were identified. Classes 1 and 2 showed increasing Sequential Organ Failure Assessment score over time and transition to persistent critical illness occurred at 16 and 27 days, respectively. The remaining classes showed a steady decline in Sequential Organ Failure Assessment scores and the transition to persistent critical illness occurred between 6 and 8 days. Elevated urea-to-creatinine ratio was a good biochemical signature of persistent critical illness.

CONCLUSIONS

While persistent critical illness occurred in a minority of patients with sepsis, it consumed vast medical resources. The transition time differs substantially across latent classes, indicating that the allocation of medical resources should be tailored to different classes of patients.

The chronic ICU patient: Is intensive care worthwhile for patients with very prolonged ICU-stay (≥ 90 days)?

BACKGROUND

Due to medical advances, an increasing number of patients are surviving the acute critical illness. However, some patients require a prolonged critical care treatment. Data on outcome and functional status of patients with an ICU-stay ≥90 days are scarce.

METHODS

Single-center retrospective study including all adult patients with ICU stay ≥90 days treated at the department of intensive care medicine at the university medical center Hamburg-Eppendorf, Germany, between January 1st 2008 and December 31st 2016.

RESULTS

Out of 65,249 patients, we identified 96 (0.1%) patients with a very prolonged ICU stay. Median age was 61 (49.8-67) years, 30 (31%) patients were female. Patients were admitted to ICU due to abdominal (28%) reasons, followed by sepsis (23%) and transplantation (15%). Fourteen patients received organ-transplantation: 9 received liver-, 4 lung- and 1 heart-transplantation. All patients needed mechanical ventilation (MV), median duration was 74.1 (55-95.1) days. Sixty-Three (66%) patients survived the ICU-stay and 1-Year survival rate was 28%. Overall eight (8%) patients had a favourable outcome after 1-Year. Severity of illness (SOFA, SAPS II) on admission were comparable. Length of MV, use of renal replacement therapy (both p < .01) and maximum lactate (5.3 vs 11.5 mmol/l; p < .001) were significantly higher in ICU non-survivors. ICU-stay was significantly longer in ICU non-survivors (137 vs 107 days; p < .05). Cox-regression-model revealed age (HR 1.02, 95% CI 1.00-1.04, p < .05) and surgical admission (HR 0.50, 95% CI 0.28-0.90, p < .05) as independent predictors of 1-year mortality.

CONCLUSIONS

Only a small number of patients requires a very prolonged ICU stay. Two-third of patients survive the ICU stay and about one-third 1-Year. However, about 10% of patients have a remarkable recovery with a favourable overall outcome after 1-Year.

Long-stay patients in pediatric intensive care unit: Diagnostic-specific definition and predictors

Aims

To stipulate a new definition for long-stay patients (LSPs) in pediatric intensive care unit (PICU). We defined LSPs as the 10% of patients with the longest PICU length-of-stay (LOS) for each age and diagnostic group. To assess whether the thresholds (days of PICU stay) for the definition of LSPs in PICU significantly differ among diagnostic and age categories. To determine whether independent associations exist between patients’ characteristics at admission and LSPs diagnosis in pre-specified diagnostic and age groups.

Methods

This was a multicenter retrospective cohort study including all PICUs in Switzerland. Multivariable regression analysis was used to seek for association between patients’ variables at admission and LSPs

Results

We included 22,284 patients with a median (IQR) age of 12 (1–84) months. Significantly different thresholds across diagnostic and age subgroups are identified. Readmission to PICU, higher PIM2 and NEMS (a score used to quantify nursing workload at intensive care unit level) at admission were associated with higher likelihood of becoming LSPs.

Conclusions

Our results showed a significantly different definitions of LSPs for specific diagnoses and age categories. Readmission to PICU and higher acuity at admission are associated with longer PICU length-of-stay in the majority of diagnostic groups. A more personalized definition of LSPs in children based on actual patients’ characteristics should probably be used in an effort to optimize care and reduce costs.

Performance of SAPS II according to ICU length of stay: A Danish nationwide cohort study

BACKGROUND

Intensive care unit (ICU) severity scores use data available at admission or shortly thereafter. There are limited contemporary data on how the prognostic performance of these scores is affected by ICU length of stay (LOS).

METHODS

We conducted a nationwide cohort study using routinely collected health data from the Danish Intensive Care Database. We included adults with ICU admissions ≥24 hours between 1 January 2012 and 30 June 2016, who survived to ICU discharge and had valid ICU LOS and vital status data registered. We assessed discrimination of the Simplified Acute Physiology Score (SAPS) II for predicting mortality 90 days after ICU discharge, followed by recalibration of the model and assessment of standardized mortality ratios (SMRs) and calibration. Performance was assessed in the entire cohort and stratified by ICU LOS quartiles.

RESULTS

We included 44 523 patients. Increasing SAPS II was associated with increasing ICU LOS. Overall discrimination (area under the receiver-operating characteristics curve) of SAPS II was 0.70 (95% CI: 0.70-0.71), with decreasing discrimination from the first (0.75, 95% CI: 0.73-0.76) to the last (0.64, 95% CI: 0.63-0.65) ICU LOS quartile. SMRs were lower (less deaths) than expected in the first ICU LOS quartile and higher (more deaths) than expected in the last two ICU LOS quartiles. Calibration decreased with increasing ICU LOS.

CONCLUSIONS

We observed that discrimination and calibration of SAPS II decreased with increasing ICU LOS, and that this affected SMRs. These findings should be acknowledged when using SAPS II for clinical, research and administrative purposes.