Relationship Between ICU Length of Stay and Long-Term Mortality for Elderly ICU Survivors

Association of social deprivation with 1-year outcome of ICU survivors: results from the FROG-ICU study

Purpose

Intensive care unit survivors suffer from prolonged impairment, reduced quality of life, and higher mortality rates after discharge compared to the general population. Socioeconomic status may play a partial but important role in mortality and recovery. Therefore, the detection of factors that are responsible for poor long-term outcomes would be beneficial in designing targeted interventions for at-risk populations.

Methods

For an endpoint analysis, 1834 intensive care unit patients with known French Deprivation Index (FDep) scores were included from the French and euRopean Outcome reGistry in Intensive Care Units (FROG-ICU) study, which was a prospective, observational, multicenter cohort study performed in 20 French intensive care units in 13 different hospitals. Socioeconomic status was defined by using the FDep score [represented as quintiles when referring to the general French population, as quintiles when referring to the FROG-ICU cohort, or as dichotomized data (which was defined as a FDep ≤ 0 for nondeprived patients)] and by using a detailed social questionnaire that was completed 3 months after discharge. The primary outcome included an all-cause, 1-year mortality after ICU discharge when regarding socioeconomic status. The secondary outcomes included both ICU and hospital lengths of stay, both short- and medium-term mortality, and the quality of life, as assessed during the 1-year follow-up by using the Medical Outcome Survey Short Form-36 (SF-36). The Revised Impact of Event Scale (IES-R) was used to evaluate the symptoms of post-traumatic stress disorder, and the Hospital Anxiety and Depression Scale (HADS) was used to screen for anxiety and depression.

Results

Of the 1447 patients who were discharged alive from the ICU, 19.2% died over the following year. No association was found between 1-year mortality and socioeconomic status, regardless of whether this association was analyzed in quintiles (p = 0.911 in the quintiles of the general French population; p = 0.589 in the quintiles of the FROG-ICU cohort itself) or as dichotomized data [nondeprived (n = 177; 1-year mortality of 18.2%) versus deprived (n = 97; 1-year mortality of 20.5%; p = 0.304)]. Moreover, no differences were found between the nondeprived and the deprived patients in the ICU and hospital lengths of stay, ICU mortalities, in-hospital mortalities, or 28-day mortalities. The SF-36 was below the score for the normal French population throughout the follow-up period. Socially deprived patients showed significantly lower median scores in the physical function subscale [55, interquartile range (IQR) (28.8–80) vs. 65, IQR (35–90); p = 0.014], the physical role subscale [25, IQR (0–75) vs. 33.3, IQR (0–100); p = 0.022], and the overall physical component scale [47.5, IQR (30–68.8) vs. 54.4, IQR (35–78.8); p = 0.010]. Up to 31.6% of survivors presented symptoms that indicated post-traumatic stress disorder, and up to 31.5% of survivors reported clinically meaningful symptoms of anxiety or depression.

Conclusions

A lower socioeconomic status was associated with lower self-reported physical component scores in the nondeprived patients. Psychiatric symptoms are frequently reported after an ICU stay, and subsequent interventions should target those fields.

Trial registration

ClinicalTrials.gov NCT01367093; registered on June 6, 2011.

Electronic supplementary material

The online version of this article (10.1007/s00134-018-5412-5) contains supplementary material, which is available to authorized users.

Implantable Wireless Intracranial Pressure Monitoring Based on Air Pressure Sensing

A wireless intracranial pressure (ICP) monitoring system based on the air pressure sensing is proposed in this work. The proposed system is composed of an implantable ICP sensing device and a portable wireless data recorder. The ICP sensing device consists of an air pressure sensor, an ultra-thin air pouch for pressure sensing, and a low-power dedicated system-on-a-chip (SoC) for the data acquisition control and wireless transmission. The SoC consists of a power management unit, a wake-up controller, the sensor interface, a wireless transmitter, and the workflow control logic. The SoC is fabricated in 0.18 μm CMOS technology with a die area of 3.04 mm × 2 mm. Experimental results show that the prototype implantable ICP device has achieved a resolution of 0.2 mmHg and a battery lifetime of 1 week with a 3 V 50 mAh battery. The ICP device has been tested in the liquid environment. The nonlinearity error is less than ±0.4 mmHg for the full measurement range of -20 to +150 mmHg. Compared to the other implantable wireless ICP solutions in the literature, the proposed system alleviates the biocompatibility issue and increases the measurement accuracy.

Frailty and the Association Between Long-Term Recovery After Intensive Care Unit Admission

Frailty is common, although infrequently screened for among patients admitted to intensive care. Frailty has been the focus of research in geriatric medicine; however, its epidemiology and interaction with critical illness have only recently been studied. Instruments to screen for and measure frailty require refinement in intensive care settings. Frail critically ill patients are at higher risk of poor outcomes. Frail survivors of critical illness are high users of health resources. Further research is needed to understand how frailty assessment can inform decision-making before and during an episode of critical illness and during an intensive care course for frail patients.

Investigation of the Relationship Between the Burden of Raised ICP and the Length of Stay in a Neuro-Intensive Care Unit

OBJECTIVES

Raised intracranial pressure (ICP) is well known to be indicative of a poor outcome in traumatic brain injury (TBI). This phenomenon was quantified using a pressure time index (PTI) model of raised ICP burden in a paediatric population. Using the PTI methodology, this pilot study is aimed at investigating the relationship between raised ICP and length of stay (LOS) in adults admitted to a neurological intensive care unit (neuro-ICU).

MATERIALS AND METHODS

In 10 patients admitted to the neuro-ICU following TBI, ICP was measured and data from the first 24 h were analysed. The PTI is a bounded area under the curve, where the bound is the threshold limit of interest for the signal. The upper bound of 20 mmHg for ICP is commonly used in clinical practice. To fully investigate the relationship between ICP and LOS, further bounds from 1 to 40 mmHg were used during the PTI calculations. A backwards step Poisson regression model with a log link function was used to find the important thresholds for the prediction of full LOS, measured in hours, in the neuro-ICU.

RESULTS

The fit was assessed using a Chi-squared deviance goodness of fit method, which showed a non-significant p value of 0.97, indicating a correctly specified model. The backwards step strategy, minimising the model's Akaike information criteria (AIC) at each change, found that levels 13-16, 18 and 20-21 combined were the most predictive. From this model it can be shown that for every 1 mmHg/h increase in burden, as measured by the PTI, the LOS has a base exponential increase of approximately 2 h, with the largest increases in the LOS given at the 20-mmHg threshold level.

CONCLUSIONS

This model demonstrates that increased duration of raised ICP in the early monitoring period is associated with a prolonged LOS in the neuro-ICU. Further validation of the PTI model in a larger cohort is currently underway as part of the CHART-ADAPT project. Second, further adjustment with known predictors of outcome, such as severity of injury, would help to improve the fit and validate the current combination of predictors.

One-year mortality after recovery from critical illness: A retrospective cohort study

Rationale

Factors associated with one-year mortality after recovery from critical illness are not well understood. Clinicians generally lack information regarding post-hospital discharge outcomes of patients from the intensive care unit, which may be important when counseling patients and families.

Objective

We sought to determine which factors among patients who survived for at least 30 days post-ICU admission are associated with one-year mortality.

Methods

Single-center, longitudinal retrospective cohort study of all ICU patients admitted to a tertiary-care academic medical center from 2001–2012 who survived ≥30 days from ICU admission. Cox’s proportional hazards model was used to identify the variables that are associated with one-year mortality. The primary outcome was one-year mortality.

Results

32,420 patients met the inclusion criteria and were included in the study. Among patients who survived to ≥30 days, 28,583 (88.2%) survived for greater than one year, whereas 3,837 (11.8%) did not. Variables associated with decreased one-year survival include: increased age, malignancy, number of hospital admissions within the prior year, duration of mechanical ventilation and vasoactive agent use, sepsis, history of congestive heart failure, end-stage renal disease, cirrhosis, chronic obstructive pulmonary disease, and the need for renal replacement therapy. Numerous effect modifications between these factors were found.

Conclusion

Among survivors of critical illness, a significant number survive less than one year. More research is needed to help clinicians accurately identify those patients who, despite surviving their acute illness, are likely to suffer one-year mortality, and thereby to improve the quality of the decisions and care that impact this outcome.

Developing a Research Agenda for Integrating Palliative Care into Critical Care and Pulmonary Practice To Improve Patient and Family Outcomes

BACKGROUND

Palliative care is a medical specialty and philosophy of care that focuses on reducing suffering among patients with serious illness and their family members, regardless of disease diagnosis or prognosis. As critical illness or moderate to severe pulmonary disease confers significant disease-related symptom burdens, palliative care and palliative care specialists can aid in reducing symptom burden and improving quality of life among these patients and their family members.

OBJECTIVE

The objective of this article is to review the existing gaps in evidence for palliative care in pulmonary disease and critical illness and to use an interdisciplinary working group convened by the National Institutes of Health and the National Palliative Care Research Center to develop a research agenda to address these gaps.

METHODS

We completed a narrative review of the literature concerning the integration of palliative care into pulmonary and/or critical care. The review was based on recent systematic reviews on these topics as well as a summary of relevant articles identified through hand search. We used this review to identify gaps in current knowledge and develop a research agenda for the future.

RESULTS

We identified key areas of need and knowledge gaps that should be addressed to improve palliative care for patients with pulmonary and critical illness. These areas include developing and validating patient- and family-centered outcomes, identifying the key components of palliative care that are effective and cost-effective, developing and evaluating different models of palliative care delivery, and determining the effectiveness and cost-effectiveness of palliative care interventions.

CONCLUSIONS

The goal of this research agenda is to encourage researchers, clinicians, healthcare systems, and research funders to identify research that can address these gaps and improve the lives of patients with pulmonary and critical illness and their family members.

Significance of green granules in neutrophils and monocytes

Intracytoplasmic green granules in neutrophils have been the subject of conjecture and discussion. Sometimes nicknamed "death cells," these granules are often associated with severe liver disease and have been said to predict acute bad outcomes in severely ill patients. Some recommend that the laboratory community report these granules to treating clinicians as an indication of poor prognosis. We report two patients presenting with secondary liver disease who were found to have blue-green neutrophilic inclusions on the peripheral blood smear. One patient died, while the other patient recovered. We propose that this morphologic finding is likely transient and is related to liver disease and that recovery is possible. Additionally, prognosis in intensive care units continues to be determined by a number of variables, such as age, comorbidities, and severity of illness.

Admission of tetanus patients to the ICU: a retrospective multicentre study

Background

An extended course of tetanus (up to 6 weeks) requiring ICU admission and protracted mechanical ventilation (MV) may have a significant impact on short- and long-term survival. The subject is noteworthy and deserves to be discussed.

Methods

Twenty-two ICUs in France performed tetanus screenings on patients admitted between January 2000 and December 2014. Retrospective data were collected from hospital databases and through the registers of the town hall of the patients.

Results

Seventy patients were included in 15 different ICUs. Sixty-three patients suffered from severe or very severe tetanus according to the Ablett classification. The median age was 80 years [interquartile range 73–84], and 86% of patients were women. Ninety per cent of patients (n = 63) required MV for a median of 36 days [26–46], and 66% required administration of a neuromuscular-blocking agent for 23 days [14–29]. A nosocomial infection occurred in 43 patients (61%). ICU and 1-year mortality rates were 14% (n = 10) and 16% (n = 11), respectively. Forty-five per cent of deaths occurred during the first week. Advanced age, a higher SAPS II, any infection, and the use of vasopressors were significantly associated with a lower number of days alive without ventilator support by day 90. Age was the only factor that significantly differed between deceased and survivors at 1 year (83 [81–85] vs. 79 [73–84] years, respectively; p = 0.03). Sixty-one per cent of survivors suffered no impairment to their functional status.

Conclusion

In a high-income country, tetanus mainly occurs in healthy elderly women. Despite prolonged MV and extended ICU length of stay, we observed a low 1-year mortality rate and good long-term functional status.

The long-term quality of life in patients with persistent inflammation-immunosuppression and catabolism syndrome after severe acute pancreatitis: A retrospective cohort study

PURPOSE

To explore clinical characteristics and long-term quality of life (QOL) in severe acute pancreatitis (SAP) patients with persistent inflammation-immunosuppression and catabolism syndrome (PICS).

MATERIALS AND METHODS

SAP patients admitted to ICU were eligible for the retrospective cohort study if they needed prolonged intensive care (>14days). Post-ICU QOL was assessed by a questionnaire, including 36-item Short Form Health Survey (SF-36) and record of re-work in a long-term follow-up.

RESULTS

214 SAP patients were enrolled, in which 149 (69.6%) patients met the criteria of PICS. PICS patients had more complications and ICU days compared to non-PICS patients (P<0.001), and their post-ICU mortality was higher (P=0.046). When adjusted for confounders, PICS was independently associated with higher post-ICU mortality (hazard ratio 4.5; 95% CI, 1.2 to 16.3; P=0.024). The 36-item Short Form Health Survey (SF-36) score was lower for PICS group in six subscales (P<0.001). Only 28.8% patients in the PICS group returned to work compared to 60% patients in the non-PICS group (P=0.001) CONCLUSIONS: SAP patients with prolonged ICU stay had a high morbidity of PICS, which was a risk factor for the post-ICU mortality and poor long-term QOL.

Modelling risk-adjusted variation in length of stay among Australian and New Zealand ICUs

PURPOSE

Comparisons between institutions of intensive care unit (ICU) length of stay (LOS) are significantly confounded by individual patient characteristics, and currently there is a paucity of methods available to calculate risk-adjusted metrics.

METHODS

We extracted de-identified data from the Australian and New Zealand Intensive Care Society (ANZICS) Adult Patient Database for admissions between January 1 2011 and December 31 2015. We used a mixed-effects log-normal regression model to predict LOS using patient and admission characteristics. We calculated a risk-adjusted LOS ratio (RALOSR) by dividing the geometric mean observed LOS by the exponent of the expected Ln-LOS for each site and year. The RALOSR is scaled such that values <1 indicate a LOS shorter than expected, while values >1 indicate a LOS longer than expected. Secondary mixed effects regression modelling was used to assess the stability of the estimate in units over time.

RESULTS

During the study there were a total of 662,525 admissions to 168 units (median annual admissions = 767, IQR:426-1121). The mean observed LOS was 3.21 days (median = 1.79 IQR = 0.92-3.52) over the entire period, and declined on average 1.97 hours per year (95%CI:1.76-2.18) from 2011 to 2015. The RALOSR varied considerably between units, ranging from 0.35 to 2.34 indicating large differences after accounting for case-mix.

CONCLUSIONS

There are large disparities in risk-adjusted LOS among Australian and New Zealand ICUs which may reflect differences in resource utilization.

Decreased transport time to the surgical intensive care unit

INTRODUCTION

Extended stay in the emergency department (ED) is associated with worse outcomes in critically ill trauma patients. We conducted a human factors analysis to better understand impediments for patient flow when a surgical ICU (SICU bed is available in order to reduce ED LOS.

METHODS

This is a retrospective review of all trauma patients admitted to a protected SICU through the ED during 2011 and 2014. In 2010, a 24-hour protected SICU bed protocol was implemented to make a bed readily available. During 2013 human factors analysis helped to describe flow disruptions; related interventions were introduced to facilitate rapid transport from the ED to SICU. The interventions required the following prior to CT scanning: immediate ICU bed orders placed by the ED physician and ED to ICU personnel communication. Direct transport from the CT scanner to the ICU was mandated. Data including patient demographics, injury severity, ED LOS, ICU LOS, and hospital LOS was collected and compared between 2011 (PRE) and 2014 (POST).

RESULTS

A total of 305 trauma patients admitted from the ED to the SICU were analyzed; 174 patients in 2011 (PRE) and 131 in 2014 (POST). Average age was 46 years and patients had a mean admission GCS and injury severity score (ISS) of 12.3 and 15.9, respectively. The cohorts were similar in age, mechanism of injury, initial vital signs, and injury severity. After implementing the human factors interventions, decreases were noted in the mean ED LOS (2.4 v. 3.0 hours, p=0.005) and ICU LOS (4.0 v. 4.8 days, p=0.023). No differences in hospital LOS or mortality were observed.

CONCLUSIONS

While an open SICU bed protocol may facilitate rapid transport of trauma patients from the ED to the ICU, additional human factors interventions emphasizing improved communication and coordination can further reduce time spent in the ED.

LEVEL OF EVIDENCE

Level IV, Economic/Decision.

The correlation between CVP-derived parameters and the prognosis of critically ill patients

OBJECTIVE

To investigate the effect of central venous pressure on the organ dysfunction and prognosis of critically ill patients.

METHODS

We conducted a retrospective observational cohort study of 488 ICU patients with central venous pressure and its derived parameters in a half-year period in one single ICU centre to compare the length of ICU stay, critical illness scores (SOFA and APACHE II), serum creatinine and lactate levels.

RESULTS

The initial, peak and mean CVP levels of critically ill patients and length of ICU stay, peak lactate levels and SOFA scores were significantly correlated. While the peak CVP and peak creatinine levels were significantly correlated, the correlation of initial and mean CVP levels with peak creatinine was not significant. Subgroup analysis showed that in the patients with a peak CVP value above 12mmHg, the length of stay was significantly prolonged, organ function was significantly worse, and the SOFA score was significantly higher. ROC analysis showed peak levels of CVP above 11.5mmHg had the greatest ability to predict mortality of critically ill patients.

CONCLUSION

Exposure to higher levels of central venous pressure in critically ill patients is associated with a poorer prognosis and worse organ function. Therefore, central venous pressure should be kept as low as possible during hemodynamic therapy in critically ill patients.

Timing of onset and burden of persistent critical illness in Australia and New Zealand: a retrospective, population-based, observational study

BACKGROUND

Critical care physicians recognise persistent critical illness as a specific syndrome, yet few data exist for the timing of the transition from acute to persistent critical illness. Defining the onset of persistent critical illness as the time at which diagnosis and illness severity at intensive care unit (ICU) arrival no longer predict outcome better than do simple pre-ICU patient characteristics, we measured the timing of this onset at a population level in Australia and New Zealand, and the variation therein, and assessed the characteristics, burden of care, and hospital outcomes of patients with persistent critical illness.

METHODS

In this retrospective, population-based, observational study, we used data for ICU admission in Australia and New Zealand from the Australian and New Zealand Intensive Care Society Adult Patient Database. We included all patients older than 16 years of age admitted to a participating ICU. We excluded patients transferred from another hospital and those admitted to an ICU for palliative care or awaiting organ donation. The primary outcome was in-hospital mortality. Using statistical methods in evenly split development and validation samples for risk score development, we examined the ability of characteristics to predict in-hospital mortality.

FINDINGS

Between Jan, 2000, and Dec, 2014, we studied 1 028 235 critically ill patients from 182 ICUs across Australia and New Zealand. Among patients still in an ICU, admission diagnosis and physiological derangements, which accurately predicted outcome on admission (area under the receiver operating characteristics curve 0·898 [95% CI 0·897-0·899] in the validation cohort), progressively lost their predictive ability and no longer predicted outcome more accurately than did simple antecedent patient characteristics (eg, age, sex, or chronic health status) after 10 days in the ICU, thus empirically defining the onset of persistent critical illness. This transition occurred between day 7 and day 22 across diagnosis-based subgroups and between day 6 and day 15 across risk-of-death-based subgroups. Cases of persistent critical illness accounted for only 51 509 (5·0%) of the 1 028 235 patients admitted to an ICU, but for 1 029 345 (32·8%) of 3 138 432 ICU bed-days and 2 197 108 (14·7%) of 14 961 693 hospital bed-days. Overall, 12 625 (24·5%) of 51 509 patients with persistent critical illness died and only 23 968 (46·5%) of 51 509 were discharged home.

INTERPRETATION

Onset of persistent critical illness can be empirically measured at a population level. Patients with this condition consume vast resources, have high mortality, have much less chance of returning home than do typical ICU patients, and require dedicated future research. ICU clinicians should be aware that the risk of in-hospital mortality can change quickly over the first 2 weeks of an ICU course and be sure to incorporate such changes in their decision making and prognostication.

FUNDING

None.