Patient-important upper gastrointestinal bleeding in the ICU: A mixed-methods study of patient and family perspectives

INTRODUCTION

The objective of this study was to create a definition of patient-important upper gastrointestinal bleeding during critical illness as an outcome for a randomized trial.

DESIGN

This was a sequential mixed-methods qualitative-dominant multi-center study with an instrument-building aim. In semi-structured individual interviews or focus groups we elicited views from survivors of critical illness and family members of patients in the intensive care unit (ICU) regarding which features indicate important gastrointestinal bleeding. Quantitative demographic characteristics were collected. We analyzed qualitative data using inductive content analysis to develop a definition for patient-important upper gastrointestinal bleeding.

SETTING

Canada and the United States.

PARTICIPANTS

51 ICU survivors and family members of ICU patients.

RESULTS

Participants considered gastrointestinal bleeding to be important if it resulted in death, disability, or prolonged hospitalization. The following also signaled patient-important upper gastrointestinal bleeding: blood transfusion, vasopressors, endoscopy, CT-angiography, or surgery. Whether an intervention evinced concern depended on its effectiveness, side-effects, invasiveness and accessibility; contextual influences included participant familiarity and knowledge of interventions and trust in the clinical team.

CONCLUSIONS

Survivors of critical illness and family members described patient-important upper gastrointestinal bleeding differently than current definitions of clinically-important upper gastrointestinal bleeding.

Models of intensive care unit follow-up care and feasibility of intervention delivery: A systematic review

BACKGROUND

The optimal model of outpatient intensive care unit (ICU) follow-up care remains uncertain, and there is limited evidence of benefit.

RESEARCH QUESTION

The objective of this research is to describe existing models of outpatient ICU follow-up care, quantify participant recruitment and retention, and describe facilitators of patient engagement.

STUDY DESIGN & METHODS

A systematic search of the MEDLINE and EMBASE databases was undertaken in June 2021. Two independent reviewers screened titles, abstracts, and full texts against eligibility criteria. Studies of adults with any outpatient ICU follow-up were included. Studies were excluded if published before 1990, not published in English, or of paediatric patients. Quantitative data were extracted using predefined data fields. Key themes were extracted from qualitative studies. Risk of bias was assessed.

RESULTS

A total of 531 studies were screened. Forty-seven studies (32 quantitative and 15 qualitative studies) with a total of 5998 participants were included. Of 33 quantitative study interventions, the most frequently reported model of care was in-person hospital-based interventions (n = 27), with 10 hybrid (part in-hospital, part remote) interventions. Literature was limited for interventions without hospital attendance (n = 6), including telehealth and diaries. The median ranges of rates of recruitment, rates of intervention delivery, and retention to outcome assessment for hospital-based interventions were 51.5% [24-94%], 61.9% [8-100%], and 52% [8.1-82%], respectively. Rates were higher for interventions without hospital attendance: 82.6% [60-100%], 68.5% [59-89%], and 75% [54-100%]. Facilitators of engagement included patient-perceived value of follow-up, continuity of care, intervention accessibility and flexibility, and follow-up design. Studies had a moderate risk of bias.

INTERPRETATION

Models of post-ICU care without in-person attendance at the index hospital potentially have higher rates of recruitment, intervention delivery success, and increased participant retention when compared to hospital-based interventions.

PROSPERO REGISTRATION

CRD42021260279.

Perioperative management of long-acting glucagon-like peptide-1 (GLP-1) receptor agonists: concerns for delayed gastric emptying and pulmonary aspiration

Prescriptions and use of glucagon-like peptide-1 (GLP-1) receptor agonists are increasing dramatically, as indications are expanding from the treatment of diabetes mellitus to weight loss for people with obesity. As GLP-1 receptor agonists delay gastric emptying, perioperative healthcare practitioners could be concerned about an increased risk for pulmonary aspiration during general anaesthesia. We summarise relevant medical literature and provide evidence-based recommendations for perioperative care for people taking GLP-1 receptor agonists. GLP-1 receptor agonists delay gastric emptying; however, ongoing treatment attenuates this effect. The risk of aspiration during general anaesthesia is unknown. However, we advise caution in patients who recently commenced on GLP-1 receptor agonists. After over 12 weeks of treatment, standard fasting times likely suffice to manage the risk of pulmonary aspiration for most otherwise low-risk patients.

Plasma beta-hydroxy-beta-methylbutyrate availability after enteral administration during critical illness after trauma: An exploratory study

BACKGROUND

During critical illness skeletal muscle wasting occurs rapidly. Although beta-hydroxy-beta-methylbutyrate (HMB) is a potential treatment to attenuate this process, the plasma appearance and muscle concentration is uncertain.

METHODS

This was an exploratory study nested within a blinded, parallel group, randomized clinical trial in which critically ill patients after trauma received enteral HMB (3 g daily) or placebo. Plasma samples were collected at 0, 60, and 180 min after study supplement administration on day 1. Needle biopsies of the vastus lateralis muscle were collected (baseline and day 7 of the HMB treatment intervention period). An external standard curve was used to calculate HMB concentrations in plasma and muscle.

RESULTS

Data were available for 16 participants (male n = 12 (75%), median [interquartile range] age 50 [29-58] years) who received placebo and 18 participants (male n = 14 (78%), age 49 [34-55] years) who received HMB. Plasma HMB concentrations were similar at baseline but increased after HMB (T = 60 min: placebo 0.60 [0.44-1.31]  µM; intervention 51.65 [22.76-64.72]  µM). Paired muscle biopsies were collected from 11 participants (placebo n = 7, HMB n = 4). Muscle HMB concentrations were similar at baseline between groups (2.35 [2.17-2.95]; 2.07 [1.78-2.31] µM). For participants in the intervention group who had the repeat biopsy within 4 h of HMB administration, concentrations were greater (7.2 and 12.3 µM) than those who had the repeat biopsy >4 h after HMB (2.7 and 2.1 µM).

CONCLUSION

In this exploratory study, enteral HMB administration increased plasma HMB availability. The small sample size limits interpretation of the muscle HMB findings.

Association between protocol change to a higher-protein formula with lower energy targets and nutrient delivery in critically ill patients with COVID-19: A retrospective cohort study

BACKGROUND

Guidelines recommend prioritizing protein provision while avoiding excessive energy delivery to critically ill patients with coronavirus disease 2019 (COVID-19), but there are no prospective studies evaluating such a targeted approach in this group. We aimed to evaluate the effect of a "higher-protein formula protocol" on protein, energy, and volume delivery when compared with standard nutrition protocol.

METHODS

This was a retrospective cohort study of adult patients with COVID-19 who received mechanical ventilation for >72 h and enteral nutrition. Before October 2021, the standard nutrition protocol for patients was 0.7 ml/kg/h ideal body weight (IBW) of a 63 g/L protein and 1250 kcal/L formula. From October 2021, we implemented a higher-protein formula protocol for patients with COVID-19. The initial prescription was 0.5 ml/kg/h IBW of a 100 g/L protein and 1260 kcal/L formula with greater emphasis on energy targets being directed by indirect calorimetry when possible. Measured outcomes included protein, energy, and volume delivered.

RESULTS

There were 114 participants (standard protocol, 48; higher-protein protocol, 66) with 1324 days of nutrition support. The median (95% CI) differences in protein, energy, and volume delivery between targeted and standard protocol periods were 0.08 g/kg/day (-0.02 to 0.18 g/kg/day), -1.71 kcal/kg/day (-3.64 to 0.21 kcal/kg/day) and -1.5 ml/kg/day (-2.9 to -0.1 ml/kg/day). Thirty-three patients (standard protocol, 7; higher-protein protocol, 26) had 44 indirect calorimetry assessments. There was no difference in measured energy expenditure over time (increased by 0.49 kcal/kg/day [-0.89 to 1.88 kcal/kg/day]).

CONCLUSION

Implementation of a higher-protein formula protocol to patients with COVID-19 modestly reduced volume administration without impacting protein and energy delivery.

Clinician- and Patient-Identified Solutions to Reduce the Fragmentation of Post-ICU Care in Australia

BACKGROUND

Critical care survivors experience multiple care transitions, with no formal follow-up care pathway.

RESEARCH QUESTION

What are the potential solutions to improve the communication between treating teams and integration of care following an ICU admission, from the perspective of patients, their caregivers, intensivists, and general practitioners (GPs) from diverse socioeconomic areas?

STUDY DESIGN AND METHODS

This study included a qualitative design using semi-structured interviews with intensivists, GPs, and patients and caregivers. Framework analysis was used to analyze data and to identify solutions to improve the integration of care following hospital discharge. Patients were previously mechanically ventilated for > 24 h in the ICU and had access to a video-enabled device. Clinicians were recruited from hospital networks and a state-wide GP network.

RESULTS

Forty-six interviews with clinicians, patients, and caregivers were completed (15 intensivists, 8 GPs, 15 patients, and 8 caregivers). Three higher level feedback loops were identified that comprised 10 themes. Feedback loop 1 was an ICU and primary care collaboration. It included the following: (1) developing collaborative relationships between the ICU and primary care; (2) providing interprofessional education and resources to support primary care; and (3) improving role clarity for patient follow-up care. Feedback loop 2 was developing mechanisms for improved communication across the care continuum. It included: (4) timely, concise information-sharing with primary care on post-ICU recovery; (5) survivorship-focused information-sharing across the continuum of care; (6) empowering patients and caregivers in self-management; and (7) creation of a care coordinator role for survivors. Feedback loop 3 was learning from post-ICU outcomes to improve future care. It included: (8) developing comprehensive post-ICU care pathways; (9) enhancing support for patients following a hospital stay; and (10) integration of post-ICU outcomes within the ICU to improve clinician morale and understanding.

INTERPRETATION

Practical solutions to enhance the quality of survivorship for critical care survivors and their caregivers were identified. These themes are mapped to a novel conceptual model that includes key feedback loops for health system improvements and foci for future interventional trials to improve ICU survivorship outcomes.

In-person peer support for critical care survivors: The ICU REcovery Solutions cO-Led through surVivor Engagement (ICURESOLVE) pilot randomised controlled trial

BACKGROUND

Peer support is a promising intervention to mitigate post-ICU disability, however there is a paucity of rigorously designed studies.

OBJECTIVES

The objective of this study was to establish feasibility of an in-person, co-designed, peer-support model.

METHODS

Prospective, randomised, adaptive, single-centre pilot trial with blinded outcome assessment, conducted at a university-affiliated hospital in Melbourne, Australia. Intensive care unit survivors (and their nominated caregiver, where survivor and caregiver are referred to as a dyad), >18 years of age, able to speak and understand English and participate in phone surveys, were eligible. Participants were randomised to the peer-support model (six sessions, fortnightly) or usual care (no follow-up or targeted information). Two sequential models were piloted: 1. Early (2-3 weeks post hospital discharge) 2. Later (4-6 weeks post hospital discharge). Primary outcome was feasibility of implementation measured by recruitment, intervention attendance, and outcome completion. Secondary outcomes included post-traumatic stress and social support.

RESULTS

Of the 231 eligible patients, 80 participants were recruited. In the early model we recruited 38 participants (28 patients, 10 carers; 18 singles, 10 dyads), with an average (standard deviation) age of 60 (18) years; 55 % were female. Twenty-two participants (58 %) were randomised to intervention. Participants in the early intervention model attended a median (interquartile range) of 0 (0-1) sessions (total 24 sessions), with 53% (n = 20) completing the main secondary outcome of interest (Impact of Event Scale) at the baseline and 37 % (n = 14) at the follow-up. For the later model we recruited 42 participants (32 patients, 10 carers; 22 singles, 10 dyads), with an average (standard deviation) age of 60.4 (15.4) years; 50 % were female. Twenty-one participants (50 %) were randomised to intervention. The later intervention model attended a median (interquartile range) of 1 (0-5) sessions (total: 44 sessions), with the main secondary outcome impact of events scale (IES-R) completed by 41 (98 %) participants at baseline and 29 (69 %) at follow-up.

CONCLUSIONS

In this pilot trial, a peer-support model that required in-person attendance delivered in a later posthospital phase of recovery appeared more feasible than an early model. Further research should investigate alternative modes of intervention delivery to improve feasibility (ACTRN12621000737831).

Feasibility of Embedding a Randomised Clinical Trial (RCT) into an Electronic Medical Record (EMR) for Patients Admitted to an Intensive Care Unit (ICU)

To establish the feasibility of embedding an RCT into EMR in the ICU, we evaluated the route of phosphate replacement. The EMR screened 207 patients who met the inclusion criteria from 20 April 2022 to 30 June 2022. 162 patients were randomised and 145 patients allocated to treatment. Our study showed that it was feasible to embed screening, randomisation, and treatment allocation for an RCT within an EMR in the ICU.

Angiotensin II treatment is associated with improved oxygenation in ARDS patients with refractory vasodilatory shock

BACKGROUND

The physiological effects of renin-angiotensin system modulation in acute respiratory distress syndrome (ARDS) remain controversial and have not been investigated in randomized trials. We sought to determine whether angiotensin-II treatment is associated with improved oxygenation in shock-associated ARDS.

METHODS

Post-hoc subgroup analysis of the Angiotensin Therapy for High Output Shock (ATHOS-3) trial. We studied patients who met modified Berlin ARDS criteria at enrollment. The primary outcome was PaO2/FiO2-ratio (P:F) at 48-h adjusted for baseline P:F. Secondary outcomes included oxygenation index, ventilatory ratio, PEEP, minute-ventilation, hemodynamic measures, patients alive and ventilator-free by day-7, and mortality.

RESULTS

Of 81 ARDS patients, 34 (42%) and 47 (58%) were randomized to angiotensin-II or placebo, respectively. In angiotensin-II patients, mean P:F increased from 155 mmHg (SD: 69) at baseline to 265 mmHg (SD: 160) at hour-48 compared with no change with placebo (148 mmHg (SD: 63) at baseline versus 164 mmHg (SD: 74) at hour-48)(baseline-adjusted difference: + 98.4 mmHg [95%CI 35.2-161.5], p = 0.0028). Similarly, oxygenation index decreased by - 6.0 cmH2O/mmHg at hour-48 with angiotensin-II versus - 0.4 cmH2O/mmHg with placebo (baseline-adjusted difference: -4.8 cmH2O/mmHg, [95%CI - 8.6 to - 1.1], p = 0.0273). There was no difference in PEEP, minute ventilation, or ventilatory ratio. Twenty-two (64.7%) angiotensin-II patients had sustained hemodynamic response to treatment at hour-3 versus 17 (36.2%) placebo patients (absolute risk-difference: 28.5% [95%CI 6.5-47.0%], p = 0.0120). At day-7, 7/34 (20.6%) angiotensin-II patients were alive and ventilator-free versus 5/47(10.6%) placebo patients. Day-28 mortality was 55.9% in the angiotensin-II group versus 68.1% in the placebo group.

CONCLUSIONS

In post-hoc analysis of the ATHOS-3 trial, angiotensin-II was associated with improved oxygenation versus placebo among patients with ARDS and catecholamine-refractory vasodilatory shock. These findings provide a physiologic rationale for trials of angiotensin-II as treatment for ARDS with vasodilatory shock.

TRIAL REGISTRATION

ClinicalTrials.Gov Identifier: NCT02338843 (Registered January 14th 2015).

Cerebrospinal fluid and plasma ascorbate concentrations following subarachnoid haemorrhage

Background

Ascorbate, the biologically active form of vitamin C, is the primary neural anti-oxidant. Ascorbate concentrations have never been quantified following aneurysmal subarachnoid haemorrhage (aSAH).

Objective

To quantify plasma and cerebrospinal fluid (CSF) ascorbate concentrations in patients following SAH.

Design Setting Participants Main Outcome Measures

Cohort study in which plasma and CSF ascorbate concentrations were measured longitudinally in 12 aSAH patients admitted to a quaternary referral intensive care unit and compared to one-off samples obtained from 20 pregnant women prior to delivery in a co-located obstetric hospital. Data are median [interquartile range] or median (95 % confidence intervals).

Results

Forty-eight plasma samples were obtained from the 12 aSAH patients (eight females, age 62 [53-68] years). Eight participants with extra-ventricular drains provided 31 paired CSF-plasma samples. Single plasma and CSF samples were obtained from 20 pregnant women (age 35 [31-37] years). Initial plasma and CSF ascorbate concentrations post aSAH were less than half those in pregnant controls (plasma: aSAH: 31 [25-39] μmol/L vs. comparator: 64 [59-77] μmol/L; P < 0.001 and CSF: 116 [80-142] μmol/L vs. 252 [240-288] μmol/L; P < 0.001). Post aSAH there was a gradual reduction in the CSF:plasma ascorbate ratio from ∼4:1 to ∼1:1. Six (50 %) patients developed vasospasm and CSF ascorbate concentrations were lower in these patients (vasospasm: 61 (25, 97) vs. no vasospasm: 110 (96, 125) μmol/L; P = 0.01).

Conclusion

Post aSAH there is a marked reduction in CSF ascorbate concentration that is most prominent in those who develop vasospasm.

REVISE: Re-Evaluating the Inhibition of Stress Erosions in the ICU: a randomised trial protocol

INTRODUCTION

The Re-Evaluating the Inhibition of Stress Erosions (REVISE) Trial aims to determine the impact of the proton pump inhibitor pantoprazole compared with placebo on clinically important upper gastrointestinal (GI) bleeding in the intensive care unit (ICU), 90-day mortality and other endpoints in critically ill adults. The objective of this report is to describe the rationale, methodology, ethics and management of REVISE.

METHODS AND ANALYSIS

REVISE is an international, randomised, concealed, stratified, blinded parallel-group individual patient trial being conducted in ICUs in Canada, Australia, Saudi Arabia, UK, US, Kuwait, Pakistan and Brazil. Patients≥18 years old expected to remain invasively mechanically ventilated beyond the calendar day after enrolment are being randomised to either 40 mg pantoprazole intravenously or an identical placebo daily while mechanically ventilated in the ICU. The primary efficacy outcome is clinically important upper GI bleeding within 90 days of randomisation. The primary safety outcome is 90-day all-cause mortality. Secondary outcomes include rates of ventilator-associated pneumonia, Clostridioides difficile infection, new renal replacement therapy, ICU and hospital mortality, and patient-important GI bleeding. Tertiary outcomes are total red blood cells transfused, peak serum creatinine level in the ICU, and duration of mechanical ventilation, ICU and hospital stay. The sample size is 4800 patients; one interim analysis was conducted after 2400 patients had complete 90-day follow-up; the Data Monitoring Committee recommended continuing the trial.

ETHICS AND DISSEMINATION

All participating centres receive research ethics approval before initiation by hospital, region or country, including, but not limited to - Australia: Northern Sydney Local Health District Human Research Ethics Committee and Mater Misericordiae Ltd Human Research Ethics Committee; Brazil: Comissão Nacional de Ética em Pesquisa; Canada: Hamilton Integrated Research Ethics Board; Kuwait: Ministry of Health Standing Committee for Coordination of Health and Medical Research; Pakistan: Maroof Institutional Review Board; Saudi Arabia: Ministry of National Guard Health Affairs Institutional Review Board: United Kingdom: Hampshire B Research Ethics Committee; United States: Institutional Review Board of the Nebraska Medical Centre. The results of this trial will inform clinical practice and guidelines worldwide.

TRIAL REGISTRATION NUMBER

NCT03374800.

Beta-hydroxy-beta-methylbutyrate supplementation and functional outcomes in multitrauma patients: A pilot randomized controlled trial

BACKGROUND

Beta-hydroxy-beta-methylbutyrate (HMB) is a nutrition supplement that may attenuate muscle wasting from critical illness. This trial aimed to determine feasibility of administering a blinded nutrition supplement in the intensive care unit (ICU) and continuing it after ICU discharge.

METHODS

Single-center, parallel-group, blinded, placebo-controlled, randomized feasibility trial. After traumatic injury necessitating admission to ICU, participants were randomized to receive an enteral study supplement of 3 g of HMB (intervention) or placebo daily for 28 days or until hospital discharge. Primary outcome was feasibility of administering the study supplement, quantified as protocol adherence. Secondary outcomes included change in quadriceps muscle thickness, measured weekly until day 28 or hospital discharge by using ultrasound and analyzed by using a linear mixed model.

RESULTS

Fifty randomized participants (intervention, n = 26; placebo, n = 24) showed comparable baseline characteristics. Participants received 862 (84.3%) of the 1022 prescribed supplements during hospitalization with 543 (62.8%) delivered via an enteral feeding tube. The median (IQR) number of study supplements successfully administered per participant was 19.5 (13.0-24.0) in the intervention group and 16.5 (8.5-23.5) in the placebo group. Marked loss of quadriceps muscle thickness occurred in both groups, with the point estimate favoring attenuated muscle loss with the intervention, albeit with wide CIs (mean intervention difference after 28 days, 0.26 cm [95% CI, -0.13 to 0.64]).

CONCLUSION

A blinded, placebo-controlled, randomized clinical trial of daily enteral HMB supplementation for up to 28 days in hospital is feasible. Any effect of HMB supplementation to attenuate muscle wasting after traumatic injury remains uncertain.

Study protocol for TARGET protein: The effect of augmented administration of enteral protein to critically ill adults on clinical outcomes: A cluster randomised, cross-sectional, double cross-over, clinical trial

Background

It is unknown whether increasing dietary protein to 1.2-2.0 g/kg/day as recommended in international guidelines compared to current practice improves outcomes in intensive care unit (ICU) patients. The TARGET Protein trial will evaluate this.

Objective

To describe the study protocol for the TARGET Protein trial.

Design setting and participants

TARGET Protein is a cluster randomised, cross-sectional, double cross-over, pragmatic clinical trial undertaken in eight ICUs in Australia and New Zealand. Each ICU will be randomised to use one of two trial enteral formulae for three months before crossing over to the other formula, which is then repeated, with enrolment continuing at each ICU for 12 months. All patients aged ≥16 years in their index ICU admission commencing enteral nutrition will be eligible for inclusion. Eligible patients will receive the trial enteral formula to which their ICU is allocated. The two trial enteral formulae are isocaloric with a difference in protein dose: intervention 100g/1000 ml and comparator 63g/1000 ml. Staggered recruitment commenced in May 2022.

Main outcomes measures

The primary outcome is days free of the index hospital and alive at day 90. Secondary outcomes include days free of the index hospital at day 90 in survivors, alive at day 90, duration of invasive ventilation, ICU and hospital length of stay, incidence of tracheostomy insertion, renal replacement therapy, and discharge destination.

Conclusion

TARGET Protein aims to determine whether augmented enteral protein delivery reduces days free of the index hospital and alive at day 90.

Trial registration

Australian New Zealand Clinical Trials Registry (ACTRN12621001484831).

Protocol summary and statistical analysis plan for the low oxygen intervention for cardiac arrest injury limitation (LOGICAL) trial

Background

The effect of conservative vs. liberal oxygen therapy on outcomes of intensive care unit (ICU) patients with hypoxic ischaemic encephalopathy (HIE) is uncertain and will be evaluated in the Low Oxygen Intervention for Cardiac Arrest injury Limitation (LOGICAL) trial.

Objective

The objective of this study was to summarise the protocol and statistical analysis plans for the LOGICAL trial.

Design setting and participants

LOGICAL is a randomised clinical trial in adults in the ICU who are comatose with suspected HIE (i.e., those who have not obeyed commands following return of spontaneous circulation after a cardiac arrest where there is clinical concern about possible brain damage). The LOGICAL trial will include 1400 participants and is being conducted as a substudy of the Mega Randomised registry trial comparing conservative vs. liberal oxygenation targets in adults receiving unplanned invasive mechanical ventilation in the ICU (Mega-ROX).

Main outcome measures

The primary outcome is survival with favourable neurological function at 180 days after randomisation as measured with the Extended Glasgow Outcome Scale (GOS-E). A favourable neurological outcome will be defined as a GOS-E score of lower moderate disability or better (i.e. a GOS-E score of 5-8). Secondary outcomes include survival time, day 180 mortality, duration of invasive mechanical ventilation, ICU length of stay, hospital length of stay, the proportion of patients discharged home, quality of life assessed at day 180 using the EQ-5D-5L, and cognitive function assessed at day 180 using the Montreal Cognitive Assessment (MoCA-blind).

Conclusions

The LOGICAL trial will provide reliable data on the impact of conservative vs. liberal oxygen therapy in ICU patients with suspected HIE following resuscitation from a cardiac arrest. Prepublication of the LOGICAL protocol and statistical analysis plan prior to trial conclusion will reduce the potential for outcome-reporting or analysis bias.

Trial registration

Australian and New Zealand Clinical Trials Registry (ACTRN12621000518864).

Relationship of blood thiamine pyrophosphate to plasma phosphate and the response to enteral nutrition plus co-administration of intravenous thiamine during critical illness

BACKGROUND

Hypovitamin B1 occurs frequently during critical illness but is challenging to predict or rapidly diagnose. The aim of this study was to evaluate whether plasma phosphate concentrations predict hypovitamin B1, enteral nutrition prevents hypovitamin B1 and intravenous thiamine supplementation achieves supraphysiological concentrations in critically ill patients.

METHODS

Thirty-two enterally fed critically ill patients, with a plasma phosphate concentration ≤0.65 mmol/L, formed a nested cohort within a larger randomised clinical trial. Patients were assigned to receive intravenous thiamine (200 mg) twice daily, and controls were not administered intravenous thiamine. Thiamine pyrophosphate concentrations were measured at four time points (pre- and post-infusion and 4- and 6-h post-infusion) on days 1 and 3 in those allocated to thiamine and once in the control group.

RESULTS

Baseline thiamine pyrophosphate concentrations were similar (intervention 88 [67, 93] vs. control 89 [62, 110] nmol/L, p = 0.49). Eight (25%) patients had hypovitamin B1 (intervention 3 vs. control 5), with two patients in the control group remaining insufficient at day 3. There was no association between baseline phosphate and thiamine pyrophosphate concentrations. Intravenous thiamine achieved supraphysiological concentrations 6 h post first infusion, with concentrations increasing to day 3. In the control group, thiamine pyrophosphate concentrations were not statistically different between baseline and day 3 (mean change: 8.6 [-6.0, 23.1] nmol/L, p = 0.25).

CONCLUSIONS

Phosphate concentrations did not predict hypovitamin B1, which was observed in 25% of the participants. Enteral nutrition alone prevented the development of new hypovitamin B1. Administration of a single 200-mg dose of intravenous thiamine achieved supraphysiological concentrations of thiamine pyrophosphate, with repeated dosing sustaining this effect.

Gastrointestinal function in critically ill patients

PURPOSE OF REVIEW

To summarize recent evidence regarding the diagnosis of acute gastrointestinal dysfunction and enteral feeding intolerance, and relationship of these to development of multiple organ dysfunction syndrome, during critical illness.

RECENT FINDINGS

Novel gastric feeding tubes that attenuate gastroesophageal regurgitation or facilitate continuous monitoring of gastric motility have been developed. The definition of enteral feeding intolerance remains controversial, which may be resolved using a consensus process. A novel scoring system for gastrointestinal dysfunction (GIDS - GastroIntestinal Dysfunction Score) was recently developed but it is not yet validated or tested to evaluate the effect of any interventions. Studies of biomarkers to identify gastrointestinal dysfunction have yet to yield a suitable biomarker for daily clinical use.

SUMMARY

The assessment of gastrointestinal function in critically ill patients continues to rely on complex daily clinical assessment. Scoring systems, consensus definitions and novel technology appear the most promising tools and interventions to improve patient care.

The impact of high versus standard enteral protein provision on functional recovery following intensive care admission (PRECISE trial): study protocol for a randomized controlled, quadruple blinded, multicenter, parallel group trial in mechanically ventilated patients

BACKGROUND

Critically ill patients are subject to severe skeletal muscle wasting during intensive care unit (ICU) stay, resulting in impaired short- and long-term functional outcomes and health-related quality of life. Increased protein provision may improve functional outcomes in ICU patients by attenuating skeletal muscle breakdown. Supporting evidence is limited however and results in great variety in recommended protein targets.

METHODS

The PRECISe trial is an investigator-initiated, bi-national, multi-center, quadruple-blinded randomized controlled trial with a parallel group design. In 935 patients, we will compare provision of isocaloric enteral nutrition with either a standard or high protein content, providing 1.3 or 2.0 g of protein/kg/day, respectively, when fed on target. All unplanned ICU admissions with initiation of invasive mechanical ventilation within 24 h of admission and an expected stay on ventilator support of at least 3 days are eligible. The study is designed to assess the effect of the intervention on functional recovery at 1, 3, and 6 months following ICU admission, including health-related quality of life, measures of muscle strength, physical function, and mental health. The primary endpoint of the trial is health-related quality of life as measured by the Euro-QoL-5D-5-level questionnaire Health Utility Score. Overall between-group differences will be assessed over the three time points using linear mixed-effects models.

DISCUSSION

The PRECISe trial will evaluate the effect of protein on functional recovery including both patient-centered and muscle-related outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04633421 . Registered on November 18, 2020. First patient in (FPI) on November 19, 2020. Expected last patient last visit (LPLV) in October 2023.

Sleep during and following critical illness: A narrative review

Sleep is a complex process influenced by biological and environmental factors. Disturbances of sleep quantity and quality occur frequently in the critically ill and remain prevalent in survivors for at least 12 mo. Sleep disturbances are associated with adverse outcomes across multiple organ systems but are most strongly linked to delirium and cognitive impairment. This review will outline the predisposing and precipitating factors for sleep disturbance, categorised into patient, environmental and treatment-related factors. The objective and subjective methodologies used to quantify sleep during critical illness will be reviewed. While polysomnography remains the gold-standard, its use in the critical care setting still presents many barriers. Other methodologies are needed to better understand the pathophysiology, epidemiology and treatment of sleep disturbance in this population. Subjective outcome measures, including the Richards-Campbell Sleep Questionnaire, are still required for trials involving a greater number of patients and provide valuable insight into patients’ experiences of disturbed sleep. Finally, sleep optimisation strategies are reviewed, including intervention bundles, ambient noise and light reduction, quiet time, and the use of ear plugs and eye masks. While drugs to improve sleep are frequently prescribed to patients in the ICU, evidence supporting their effectiveness is lacking.

Aggression, violence and threatening behaviour during critical illness

Objective

This article aims to quantify prevalence of patient aggression or threatened/actual violence during critical illness.

Design

This is a retrospective cohort study.

Setting

This study was conducted in single adult trauma intensive care unit (ICU).

Participants

Patients aged 18 years or over, admitted between January 2015 and December 2020, who triggered a "Code Grey" response due to aggression or threatened/actual violence.

Main outcome measure

The primary outcome was prevalence of Code Grey events. Secondary outcomes included unadjusted and adjusted (logistic mixed model) effects of patient demographics, diagnoses and severity of illness on Code Grey events.

Results

There were 16175 ICU admissions relating to 14085 patients and 807 Code Grey events involving 379 (2.7%) patients. The observed count of events increased progressively from 2015 (n = 77) to 2020 (n = 204). For patients with a Code Grey, the median count of events was 3 (range 1-33). Independent predictors of at least one ICU Code Grey event included male sex (OR 2.5; 95% CI 1.8 to 3.4), young age (most elevated odds ratio in patients 20-30 years), admission from the emergency department (OR 2.8, 95% CI 2.1 to 3.6) and a trauma diagnosis (OR 1.4, 95% CI 1.1 to 1.9). Code Grey patients had longer admissions with a reduced risk of death.

Conclusions

The prevalence of Code Grey events in ICU appears to be increasing. Patients may have repeated events. Younger male patients admitted to ICU via the emergency department with a trauma or medical diagnosis are at greatest risk of a Code Grey event.

What counts as patient-important upper gastrointestinal bleeding in the ICU? A mixed-methods study protocol of patient and family perspectives

INTRODUCTION

Clinically important upper gastrointestinal bleeding is conventionally defined as bleeding accompanied by haemodynamic changes, requiring red blood cell transfusions or other invasive interventions. However, it is unclear if this clinical definition reflects patient values and preferences. This protocol describes a study to elicit views from patients and families regarding features, tests, and treatments for upper gastrointestinal bleeding that are important to them.

METHODS AND ANALYSIS

This is a sequential mixed-methods qualitative-dominant multi-centre study with an instrument-building aim. We developed orientation tools and educational materials in partnership with patients and family members, including a slide deck and executive summary. We will invite intensive care unit (ICU) survivors and family members of former ICU patients to participate. Following a virtual interactive presentation, participants will share their perspectives in an interview or focus group. Qualitative data will be analysed using inductive qualitative content analysis, wherein codes will be derived directly from the data rather than using preconceived categories. Concurrent data collection and analysis will occur. Quantitative data will include self-reported demographic characteristics. This study will synthesise the values and perspectives of patients and family members to create a new trial outcome for a randomised trial of stress ulcer prophylaxis. This study is planned for May 2022 to August 2023. The pilot work was completed in Spring 2021.

ETHICS AND DISSEMINATION

This study has ethics approval from McMaster University and the University of Calgary. Findings will be disseminated via manuscript and through incorporation as a secondary trial outcome on stress ulcer prophylaxis.

TRIAL REGISTRATION NUMBER

NCT05506150.

Initiating angiotensin II at lower vasopressor doses in vasodilatory shock: an exploratory post-hoc analysis of the ATHOS-3 clinical trial

BACKGROUND

High dose vasopressors portend poor outcome in vasodilatory shock. We aimed to evaluate the impact of baseline vasopressor dose on outcomes in patients treated with angiotensin II (AT II).

METHODS

Exploratory post-hoc analysis of the Angiotensin II for the Treatment of High-Output Shock (ATHOS-3) trial data. The ATHOS-3 trial randomized 321 patients with vasodilatory shock, who remained hypotensive (mean arterial pressure of 55-70 mmHg) despite receiving standard of care vasopressor support at a norepinephrine-equivalent dose (NED) > 0.2 µg/kg/min, to receive AT II or placebo, both in addition to standard of care vasopressors. Patients were grouped into low (≤ 0.25 µg/kg/min; n = 104) or high (> 0.25 µg/kg/min; n = 217) NED at the time of study drug initiation. The primary outcome was the difference in 28-day survival between the AT II and placebo subgroups in those with a baseline NED ≤ 0.25 µg/kg/min at the time of study drug initiation.

RESULTS

Of 321 patients, the median baseline NED in the low-NED subgroup was similar in the AT II (n = 56) and placebo (n = 48) groups (median of each arm 0.21 µg/kg/min, p = 0.45). In the high-NED subgroup, the median baseline NEDs were also similar (0.47 µg/kg/min AT II group, n = 107 vs. 0.45 µg/kg/min placebo group, n = 110, p = 0.75). After adjusting for severity of illness, those randomized to AT II in the low-NED subgroup were half as likely to die at 28-days compared to placebo (HR 0.509; 95% CI 0.274-0.945, p = 0.03). No differences in 28-day survival between AT II and placebo groups were found in the high-NED subgroup (HR 0.933; 95% CI 0.644-1.350, p = 0.71). Serious adverse events were less frequent in the low-NED AT II subgroup compared to the placebo low-NED subgroup, though differences were not statistically significant, and were comparable in the high-NED subgroups.

CONCLUSIONS

This exploratory post-hoc analysis of phase 3 clinical trial data suggests a potential benefit of AT II introduction at lower doses of other vasopressor agents. These data may inform design of a prospective trial.

TRIAL REGISTRATION

The ATHOS-3 trial was registered in the clinicaltrials.gov repository (no. NCT02338843). Registered 14 January 2015.

Clearance of Piperacillin-Tazobactam and Vancomycin During Continuous Renal Replacement With Regional Citrate Anticoagulation

BACKGROUND

The use of regional citrate anticoagulation during continuous venovenous hemodiafiltration (CVVHDF) has increased worldwide. However, data on its effect on the pharmacokinetics of antibiotics are limited. In this study, the authors aimed to measure the clearance of piperacillin-tazobactam and vancomycin in patients receiving CVVHDF with regional citrate anticoagulation.

METHODS

This study measured piperacillin-tazobactam and vancomycin concentrations in patients receiving CVVHDF with regional citrate anticoagulation. Dosing regimens were independently selected by intensivists. Arterial blood and effluent fluid samples were obtained over a single dosing interval and analyzed using ultra-high-performance liquid chromatography with tandem mass spectrometry.

RESULTS

Seventeen sampling intervals in 15 patients (9 receiving piperacillin-tazobactam only, 4 receiving vancomycin only, and 2 receiving both) were used. The median overall clearance for piperacillin was 35.2 mL/min [interquartile range (IQR): 32.2-38.6], 70 mL/min (IQR: 62.7-76.2) for tazobactam, and 29.5 mL/min (IQR: 26.2-32) for vancomycin.

CONCLUSIONS

This is the first study to quantify the pharmacokinetics of vancomycin and piperacillin-tazobactam in patients receiving CVVHDF with regional citrate anticoagulation. These results indicate high clearance and provide key information to guide optimal dosing.

Study protocol and statistical analysis plan for the 20% Human Albumin Solution Fluid Bolus Administration Therapy in Patients after Cardiac Surgery-ll (HAS FLAIR-II) trial

Background: Fluid bolus therapy with 20% albumin may shorten the duration of vasopressor therapy in patients after cardiac surgery. Objective: To describe the study protocol and statistical analysis plan for the 20% Human Albumin Solution Fluid Bolus Administration Therapy in Patients after Cardiac Surgery-II (HAS FLAIR-II) trial. Design, setting, participants and intervention: HAS FLAIR-II is a phase 2b, multicentre, parallel group, openlabel, randomised controlled trial that will be conducted at six Australian intensive care units. Patients requiring fluid bolus therapy after cardiac surgery will be randomly assigned in a 1:1 ratio to the intervention of fluid bolus therapy with 20% albumin or a comparator of fluid bolus therapy with a crystalloid solution. Main outcome measures: The primary outcome measure is the cumulative duration of vasopressor therapy. Secondary outcomes include vasopressor use, service utilisation, and mortality. All analyses will be conducted on an intention-to-treat basis. Results and conclusion: The study protocol and statistical analysis plan will guide the conduct and analysis of the HAS FLAIR-II trial, such that analytical and reporting biases are minimised. Trial registration: This trial has been registered with the Australian New Zealand Clinical Trials Registry (ACTRN No. 12620000137998).

Modified low ratio ketogenic therapy in the treatment of adults with super-refractory status epilepticus

BACKGROUND

Induction of ketosis by manipulation of nutrition intake has been proposed as an adjunctive treatment for super-refractory status epilepticus (SRSE). However, the classical 4:1 ketogenic ratio may not meet the nutrition needs, specifically protein for critically ill adults. The aim of this study was to analyze the outcomes of adults with SRSE who received a lower ketogenic ratio of 2:1 grams of fat to non-fat grams, including 20%-30% of energy from medium chain triglycerides.

METHODS

We reviewed patients aged ≥18 years with SRSE treated with ketogenic therapy between July 2015 and December 2020 at two quaternary teaching hospitals in Melbourne, Australia. Data collected from medical records included patient demographics, nutrition prescription, clinical outcomes, and ketogenic therapy-related complications. The primary outcome of the study was to assess tolerability of ketogenic therapy.

RESULTS

Twelve patients (female = 7) were treated with ketogenic therapy for SRSE. Patients received between 4 and 8 antiseizure medications and 1-5 anesthetic agents prior to commencement of ketogenic therapy. Blood beta-hydroxybutyrate concentrations were variable (median = 0.5 mmol/L, range: 0.0-6.1 mmol/L). SRSE resolved in 10 cases (83%) after a median of 9 days (range: 2-21 days) following commencement of ketogenic therapy. Ketogenic therapy-associated complications were reported in five patients, leading to cessation in two patients.

CONCLUSION

Despite the challenge in maintaining ketosis during critical illness, low ratio 2:1 ketogenic therapy incorporating medium chain triglycerides is tolerable for adults with SRSE. Further studies are required to determine the optimal timing, nutrition prescription and duration of ketogenic therapy for SRSE treatment.

Machine learning predicts the short-term requirement for invasive ventilation among Australian critically ill COVID-19 patients

OBJECTIVE(S)

To use machine learning (ML) to predict short-term requirements for invasive ventilation in patients with COVID-19 admitted to Australian intensive care units (ICUs).

DESIGN

A machine learning study within a national ICU COVID-19 registry in Australia.

PARTICIPANTS

Adult patients who were spontaneously breathing and admitted to participating ICUs with laboratory-confirmed COVID-19 from 20 February 2020 to 7 March 2021. Patients intubated on day one of their ICU admission were excluded.

MAIN OUTCOME MEASURES

Six machine learning models predicted the requirement for invasive ventilation by day three of ICU admission from variables recorded on the first calendar day of ICU admission; (1) random forest classifier (RF), (2) decision tree classifier (DT), (3) logistic regression (LR), (4) K neighbours classifier (KNN), (5) support vector machine (SVM), and (6) gradient boosted machine (GBM). Cross-validation was used to assess the area under the receiver operating characteristic curve (AUC), sensitivity, and specificity of machine learning models.

RESULTS

300 ICU admissions collected from 53 ICUs across Australia were included. The median [IQR] age of patients was 59 [50-69] years, 109 (36%) were female and 60 (20%) required invasive ventilation on day two or three. Random forest and Gradient boosted machine were the best performing algorithms, achieving mean (SD) AUCs of 0.69 (0.06) and 0.68 (0.07), and mean sensitivities of 77 (19%) and 81 (17%), respectively.

CONCLUSION

Machine learning can be used to predict subsequent ventilation in patients with COVID-19 who were spontaneously breathing and admitted to Australian ICUs.

One-hour plasma glucose level after a 75 g oral glucose load and its relationship to gastric emptying in survivors of critical illness and stress hyperglycaemia

Objective: A 1-hour plasma glucose level ≥ 8.6 mmol/L in a 75 g oral glucose tolerance test has been strongly associated with increased morbidity and mortality in outpatients without diabetes. Our primary aim was to evaluate the 1-hour plasma glucose level in a 75 g glucose tolerance test in survivors of critical illness with stress hyperglycaemia at 3 months after intensive care unit (ICU) discharge, with the secondary aims to evaluate the 2-hour plasma glucose level, glycated haemoglobin (HbA1c), and gastric emptying. Design:Post hoc analysis of a single-centre, prospective cohort study. Setting: Single-centre, tertiary referral, mixed medical-surgical ICU. Participants: Consecutively admitted patients aged ≥ 18 years who developed stress hyperglycaemia and survived to hospital discharge were eligible. Interventions: Participants returned at 3 months after ICU discharge and underwent a 75 g oral glucose tolerance test. Main outcome measures: One- and 2-hour post load plasma glucose level, HbA1c, and assessment of gastric emptying via an isotope breath test. Results: Thirty-five patients (12 females; mean age, 58.5 years [SD, 10.5]; mean HbA1c, 37.4 mmol/mol [SD, 7.0]) attended the followup. In 32/35 patients (91%) the 1-hour post load plasma glucose level was ≥ 8.6 mmol/L. There was a positive correlation between the plasma glucose level at 1 hour (r2 = 0.21; P = 0.006), but no correlation between the 2-hour glucose level (r2 = 0.006; P = 0.63) and gastric emptying. Conclusion: Glucose intolerance, when defined as 1-hour glucose level ≥ 8.6 mmol/L following a 75 g oral glucose load, persists at 3 months in most survivors of stress hyperglycaemia and is dependent on the rate of gastric emptying. Longitudinal studies to characterise mechanisms underlying dysglycaemia and progression to diabetes in individuals with stress hyperglycaemia are indicated.

Is it time to personalise glucose targets during critical illness?

PURPOSE OF REVIEW

Dysglycaemia complicates most critical care admissions and is associated with harm, yet glucose targets, particularly in those with preexisting diabetes, remain controversial. This review will summarise advances in the literature regarding personalised glucose targets in the critically ill.

RECENT FINDINGS

Observational data suggest that the degree of chronic hyperglycaemia in critically ill patients with diabetes attenuates the relationship between mortality and several metrics of dysglycaemia, including blood glucose on admission, and mean blood glucose, glycaemic variability and hypoglycaemia in the intensive care unit. The interaction between acute and chronic hyperglycaemia has recently been quantified with novel metrics of relative glycaemia including the glycaemic gap and stress hyperglycaemia ratio. Small pilot studies provided preliminary data that higher blood glucose thresholds in critically ill patients with chronic hyperglycaemia may reduce complications of intravenous insulin therapy as assessed with biomakers. Although personalising glycaemic targets based on preexisting metabolic state is an appealing concept, the recently published CONTROLLING trial did not identify a mortality benefit with individualised glucose targets, and the effect of personalised glucose targets on patient-centred outcomes remains unknown.

SUMMARY

There is inadequate data to support adoption of personalised glucose targets into care of critically ill patients. However, there is a strong rationale empowering future trials utilising such an approach for patients with chronic hyperglycaemia.

Communication with bereaved family members after death in the ICU: the CATHARTIC randomised clinical trial

Objective: It is uncertain whether psychological distress in the family members of patients who die during an intensive care unit (ICU) admission may be improved by bereavement interventions. In this trial, relatives' symptoms of anxiety and depression after 6 months were measured when allocated to three commonly used bereavement follow-up strategies. Design: Single-centre, randomised, three parallel-group trial. Setting: A tertiary ICU in Australia. Participants: Relatives of patients who died in the ICU. Interventions: Relatives received bereavement follow-up 4 weeks after the death using a condolence letter, short telephone call or no contact. Main outcome measures: The primary outcome was the total Hospital Anxiety and Depression Scale (HADS-T) score. Secondary outcomes estimated anxiety, depression, complicated grief, post-traumatic stress, and satisfaction with ICU care. Results: Seventy-one relatives participated (24 had no contact, 19 were contacted by letter and 28 by telephone 4 weeks after the death). The mean HADS-T score for no contact was 16.1 (95% CI, 12.4-19.8). Receipt of a letter was associated with a mean HADS-T increase of 1.4 (4.0 decrease to 6.8 increase), and a condolence call was accompanied by a mean decrease of 1.6 (6.6 decrease to 3.4 increase; P > 0.5). Non-significant differences were observed for all secondary outcomes. Conclusions: Anxiety and depression at 6 months in the relatives of patients who died in the ICU was not meaningfully alleviated by receipt of either a condolence letter or telephone call. Trial registration: Australia New Zealand Clinical Trials Registry (ACTRN12619000917134).

Conservative or liberal oxygen therapy for mechanically ventilated adults with acute brain pathologies: A post-hoc subgroup analysis

PURPOSE

To compare the effect of conservative vs. liberal oxygen therapy in mechanically ventilated adults in the intensive care unit (ICU) with non-hypoxic ischemic encephalopathy (HIE) acute brain pathologies.

MATERIALS AND METHODS

Post-hoc analysis of data from 217 patients with non-HIE acute brain pathologies included in the ICU Randomized Trial Comparing Two Approaches to OXygen therapy (ICU-ROX).

RESULTS

Patients allocated to conservative oxygen spent less time with oxygen saturation ≥ 97% (50.5 [interquartile range (IQR), 18.5-119] vs. 82 h [IQR, 38-164], absolute difference, -31.5 h; 95%CI, -59.6 to -3.4). At 180 days, 38 of 110 conservative oxygen patients (34.5%) and 28 of 104 liberal oxygen patients (26.9%) had died (absolute difference, 7.6 percentage points; 95%CI, -4.7 to 19.9 percentage points; P = 0.23; interaction P = 0.02 for non-HIE acute brain pathologies vs. HIE; interaction P = 0.53 for non-HIE acute brain pathologies vs. non-neurological conditions).

CONCLUSIONS

In this post-hoc analysis, patients admitted to the ICU with non-HIE acute brain pathologies treated with conservative oxygen therapy did not have significantly lower mortality than those treated with liberal oxygen. A trial with adequate statistical power is needed to determine whether our day 180 mortality point estimate of treatment effect favoring liberal oxygen therapy indicates a true effect.

The Effect of a Liberal Approach to Glucose Control in Critically Ill Patients with Type 2 Diabetes: A multicenter, parallel-group, open-label, randomized clinical trial

Rationale Blood glucose concentrations affect outcomes in critically ill patients but the optimal target blood glucose range in those with type 2 diabetes is unknown. Objective To evaluate the effects of a 'liberal' approach to targeted blood glucose range during intensive care unit (ICU) admission. Methods This mutlicenter, parallel-group, open-label, randomized clinical trial included 419 adult patients with type 2 diabetes expected to be in the ICU on at least three consecutive days. In the intervention group intravenous insulin was commenced at a blood glucose >252 mg/dL and titrated to a target range of 180 to 252 mg/dL. In the comparator group insulin was commenced at a blood glucose >180 mg/dL and titrated to a target range of 108 to 180 mg/dL. The primary outcome was incident hypoglycemia (<72 mg/dL). Secondary outcomes included glucose metrics and clinical outcomes. Main Results At least one episode of hypoglycemia occurred in 10 of 210 (5%) patients assigned the intervention and 38 of 209 (18%) patients assigned the comparator (incident rate ratio: 0.21 (95% CI, 0.09 to 0.49); P<0.001). Those assigned the intervention had greater blood glucose concentrations (daily mean, minimum, maximum), less glucose variability and less relative hypoglycaemia (P<0.001 for all comparisons). By day 90, 62 of 210 (29.5%) in the intervention and 52 of 209 (24.9%) in the comparator group had died (absolute difference 4.6 percentage points (95%CI, -3.9 to 13.2%); P=0.29). Conclusions A liberal approach to blood glucose targets reduced incident hypoglycemia but did not improve patient-centered outcomes. Clinical trial registration available at www.anzctr.org.au, ID: ACTRN12616001135404.

Muscle Protein Synthesis Following Protein Administration in Critical Illness

Rationale Dietary protein may attenuate the muscle atrophy experienced by patients in the Intensive Care Unit (ICU), yet protein handling is poorly understood. Objective To quantify protein digestion and amino acid absorption, and fasting and postprandial myofibrillar protein synthesis during critical illness. Methods Fifteen mechanically ventilated adults (12M; age 50±17y, Body Mass Index (BMI) 27±5kg·m-2) and 10 healthy controls (6M; 54±23y, BMI 27±4kg·m-2) received a primed intravenous L-[ring-2H5]-phenylalanine, L-[3,5-2H2]-tyrosine, and L-[1-13C]-leucine infusion over 9.5h, and a duodenal bolus of intrinsically-labelled (L-[1-13C]-phenylalanine and L-[1-13C]-leucine) intact milk protein (20g protein) over 60min. Arterial blood and muscle samples were taken at baseline (fasting) and for 6h following duodenal protein administration. Data are mean±SD; analysed with 2-way repeated measures ANOVA and independent samples t-test. Measurements and main results Fasting myofibrillar protein synthesis rates did not differ between ICU patients and healthy controls (0.023±0.013 vs 0.034±0.016%/h; P=0.077). Following protein administration, plasma amino acid availability did not differ between groups (ICU patients 54.2±9.1 vs healthy controls 61.8±13.1%; P=0.12), and myofibrillar protein synthesis rates increased in both groups (0.028±0.010 vs 0.043±0.018 %/h, main time effect P=0.046, P-interaction=0.584) with lower rates in ICU patients compared to healthy controls (main group effect P=0.001). Incorporation of protein-derived phenylalanine into myofibrillar protein was ~60% lower in ICU patients (0.007±0.007 vs 0.017±0.009 mole % excess (MPE); P=0.007). Conclusion The capacity for critically ill patients to use ingested protein for muscle protein synthesis is markedly blunted despite relatively normal protein digestion and amino acid absorption.

Protocol summary and statistical analysis plan for ntensive utrition herapy compard to usual care i criically ill adults (INTENT): a phase II randomised controlled trial

INTRODUCTION

It is plausible that a longer duration of nutrition intervention may have a greater impact on clinical and patient-centred outcomes. The Intensive Nutrition care Therapy comparEd to usual care iN criTically ill adults (INTENT) trial will determine if a whole hospital nutrition intervention is feasible and will deliver more total energy compared with usual care in critically ill patients with at least one organ system failure.

METHODS AND ANALYSIS

This study is a prospective, multicentre, unblinded, parallel-group, phase II randomised controlled trial (RCT) conducted in 23 hospitals in Australia and New Zealand. Mechanically ventilated critically ill adult patients with at least one organ failure who have been in intensive care unit (ICU) for 72-120 hours and meet all of the inclusion and none of the exclusion criteria will be randomised to receive either intensive or usual nutrition care. INTENT started recruitment in October 2018 and a sample size of 240 participants is anticipated to be recruited in 2022. The study period is from randomisation to hospital discharge or study day 28, whichever occurs first, and the primary outcome is daily energy delivery from nutrition therapy. Secondary outcomes include daily energy and protein delivery during ICU and in the post-ICU period, duration of ventilation, ventilator-free days, total bloodstream infection rate and length of hospital stay. All other outcomes are considered tertiary and results will be analysed on an intention-to-treat basis.

ETHICS AND DISSEMINATION

Ethics approval has been received in Australia (Alfred Hospital Ethics Committee (HREC/18/Alfred/101) and Human Research Ethics Committee of the Northern Territory Department of Health (2019-3372)) and New Zealand (Northern A Health and Disability Ethics Committee (18/NTA/222). Results will be disseminated in an international peer-reviewed journal(s), at scientific meetings and via social media.

TRIAL REGISTRATION NUMBER

NCT03292237.

β-Hydroxy-β-methylbutyrate (HMB) supplementation and functional outcomes in multi-trauma patients: a study protocol for a pilot randomised clinical trial (BOOST trial)

Background

There are no therapies proven to diminish the muscle wasting that occurs in patients after major trauma who are admitted to the intensive care unit (ICU). β-Hydroxy-β-methylbutyrate (HMB) is a nutrition intervention that may attenuate muscle loss and, thereby, improve recovery. The primary aim of this study is to determine the feasibility of a blinded randomised clinical trial of HMB supplementation to patients after major trauma who are admitted to the ICU. Secondary aims are to establish estimates for the impact of HMB when compared to placebo on muscle mass and nutrition-related patient outcomes.

Methods

This prospective, single-centre, blinded, randomised, placebo-controlled, parallel-group, feasibility trial with allocation concealment will recruit 50 participants over 18 months. After informed consent, participants will be randomised [1:1] to receive either the intervention (three grams of HMB dissolved in either 150 ml of orange juice for those allowed oral intake or 150 ml of water for those being enterally fed) or placebo (150 ml of orange juice for those allowed oral intake or 150 ml of water for those being enterally fed). The intervention will be commenced in ICU, continued after ICU discharge and ceased at hospital discharge or day 28 post randomisation, whichever occurs first. The primary outcome is the feasibility of administering the intervention. Secondary outcomes include change in muscle thickness using ultrasound and other nutritional and patient-centred outcomes.

Discussion

This study aims to determine the feasibility of administering HMB to critically ill multi-trauma patients throughout ICU admission until hospital discharge. Results will inform design of a larger randomised clinical trial.

Trial registration

The protocol is registered with Australian New Zealand Clinical Trials Registry (ANZCTR) ANZCTR: 12620001305910. UTN: U1111-1259-5534.

Invasive pulmonary aspergillosis in critically ill patients with COVID-19 in Australia: implications for screening and treatment

We report four cases of invasive pulmonary aspergillus co-infection in patients with coronavirus disease 2019 (COVID-19) infection and acute respiratory distress syndrome requiring intensive care unit (ICU) admission. Aspergillus fumigatus and Aspergillus terreus were isolated, with early infection onset following ICU admission. Clinicians should be aware of invasive pulmonary aspergillosis in ICU patients with COVID-19 infection, particularly those receiving dexamethasone. We propose screening of these high-risk patients with twice-weekly fungal culture from tracheal aspirate and, if feasible, Aspergillus polymerase chain reaction. Diagnosis is challenging and antifungal treatment should be considered in critically ill patients who have new or worsening pulmonary changes on chest imaging and mycological evidence of infection.

Protein delivery in mechanically ventilated adults in Australia and New Zealand: current practice

Objective: To quantify current protein prescription and delivery in critically ill adults in Australia and New Zealand and compare it with international guidelines. Design: Prospective, multicentre, observational study. Setting: Five intensive care units (ICUs) across Australia and New Zealand. Participants: Mechanically ventilated adults who were anticipated to receive enteral nutrition for ≥ 24 hours. Main outcome measures: Baseline demographic and nutrition data in ICU, including assessment of requirements, prescription and delivery of enteral nutrition, parenteral nutrition and protein supplementation, were collected. The primary outcome was enteral nutrition protein delivery (g/kg ideal body weight [IBW] per day). Data are reported as mean ± standard deviation or n (%). Results: 120 patients were studied (sex, 60% male; mean age, 59 ± 16 years; mean admission APACHE II score, 20 ± 8). Enteral nutrition was delivered on 88%, parenteral nutrition on 6.8%, and protein supplements on 0.3% of 1156 study days. For the 73% (88/120) of patients who had a nutritional assessment, the mean estimated protein requirements were 99 ± 22 g/day (1.46 ± 0.55 g/kg IBW per day). The mean daily protein delivery was 54 ± 23 g (0.85 ± 0.35 g/kg IBW per day) from enteral nutrition and 56 ± 23 g (0.88 ± 0.35 g/kg IBW per day) from all sources (enteral nutrition, parenteral nutrition, protein supplements). Protein delivery was ≥ 1.2 g/kg IBW per day on 29% of the total study days per patient. Conclusions: Protein delivery as a part of current usual care to critically ill adults in Australia and New Zealand remains below that recommended in international guidelines.

The impact of a modified carbohydrate formula, and its constituents, on glycaemic control and inflammatory markers: A nested mechanistic sub-study

BACKGROUND

Hyperglycaemia occurs frequently in the critically ill. Dietary intake of advanced glycation end-products (AGEs), specifically Nε-(carboxymethyl)lysine (CML), may exacerbate hyperglycaemia through perturbation of insulin sensitivity. The present study aimed to determine whether the use of nutritional formulae, with varying AGE loads, affects the amount of insulin administered and inflammation.

METHODS

Exclusively tube fed patients (n = 35) were randomised to receive Nutrison Protein Plus Multifibre®, Diason® or Glucerna Select®. Insulin administration was standardised according to protocol based on blood glucose (<10 mmol L^-1 ). Samples were obtained at randomisation and 48 h later. AGEs in nutritional formula, plasma and urine were measured using mass spectrometry. Plasma inflammatory markers were measured using an enzyme-linked immunosorbent assay and multiplex bead-based assays.

RESULTS

AGE concentrations of CML in nutritional formulae were greatest with delivery of Nutrison Protein Plus® (mean [SD]; 6335 pmol mol^-1 [2436]) compared to Diason® (4836 pmol mol^-1 [1849]) and Glucerna Select® (4493 pmol mol^-1 [1829 pmol mol^-1 ]) despite patients receiving similar amounts of energy (median [interquartile range]; 12 MJ [8.2-13.7 MJ], 11.5 MJ [8.3-14.5 MJ], 11.5 MJ [8.3-14.5 MJ]). More insulin was administered with Nutrison Protein Plus® (2.47 units h^-1 [95% confidence interval (CI) = 1.57-3.37 units h^-1 ]) compared to Diason® (1.06 units h^-1 [95% CI = 0.24-1.89 units h^-1 ]) or Glucerna Select® (1.11 units h^-1 [95% CI = 0.25-1.97 units h^-1 ]; p = 0.04). Blood glucose concentrations were similar. There were associations between greater insulin administration and reductions in circulating interleukin-6 (r = -0.46, p < 0.01), tumour necrosis factor-α (r = -0.44, p < 0.05), high sensitivity C-reactive protein (r = -0.42, p < 0.05) and soluble receptor for advanced glycation end-products (r = -0.45, p < 0.01) concentrations.

CONCLUSIONS

The administration of greater AGE load in nutritional formula potentially increases the amount of insulin required to maintain blood glucose within a normal range during critical illness. There was an inverse relationship between exogenous insulin and plasma inflammatory markers.

Neutrophil kinetics and function after major trauma: A systematic review

BACKGROUND

Immune dysfunction following major traumatic injury is complex and strongly associated with significant morbidity and mortality through the development of multiple organ dysfunction syndrome (MODS), persistent inflammation, immunosuppression, and catabolism syndrome and sepsis. Neutrophils are thought to be a pivotal mediator in the development of immune dysfunction.

AIM

To provide a review with a systematic approach of the recent literature describing neutrophil kinetics and functional changes after major trauma in humans and discuss hypotheses as to the mechanisms of the observed neutrophil dysfunction in this setting.

METHODS

Medline, Embase and PubMed were searched on January 15, 2021. Papers were screened by two reviewers and those included had their reference list hand searched for additional papers of interest. Inclusion criteria were adults > 18 years old, with an injury severity score > 12 requiring admission to an intensive care unit. Papers that analysed major trauma patients as a subgroup were included.

RESULTS

Of 107 papers screened, 48 were included in the review. Data were heterogeneous and most studies had a moderate to significant risk of bias owing to their observational nature and small sample sizes. Key findings included a persistently elevated neutrophil count, stereotyped alterations in cell-surface markers of activation, and the elaboration of heterogeneous and immunosuppressive populations of cells in the circulation. Some of these changes correlate with clinical outcomes such as MODS and secondary infection. Neutrophil phenotype remains a promising avenue for the development of predictive markers for immune dysfunction.

CONCLUSION

Understanding of neutrophil phenotypes after traumatic injury is expanding. A greater emphasis on incorporating functional and clinically significant markers, greater uniformity in study design and assessment of extravasated neutrophils may facilitate risk stratification in patients affected by major trauma.

A Stabilizing Agent, PCA/DTPA, Improves Plasma Storage Life for the Chromsystems Vitamin C Assay up to Six Months

The commonly used Chromsystems vitamin C (ascorbate) assay (Munich, Germany) has a sample storage life of five days at -20°C. Stabilizing agents have been successfully used to increase longevity; however, their suitability with this commercial assay is unclear. We investigated the compatibility of a stabilizing agent, perchloric acid/diethylenetriaminepentaacetic acid (PCA/DTPA), with the Chromsystems assay. Plasma was stored at -80°C, with or without PCA/DTPA. Storage up to six months was assessed through baseline and repeat analyses, stability was assessed by comparing paired non-stabilized and PCA/DTPA-stabilized plasma, and performance was assessed using allowable performance specifications of an external quality assurance program. Ascorbate concentration was significantly lower in non-stabilized plasma than in paired PCA/DTPA-stabilized plasma, with a proportional difference of 11% (P=0.01). All storage analysis results were within the allowable performance specifications. Storage at -80°C prevented plasma ascorbate oxidation; however, substantial oxidation occurred during sample processing. In conclusion, PCA/DTPA significantly reduces ascorbate oxidation, and PCA/DTPA-stabilized ascorbate plasma is compatible with the Chromsystems assay and stable for up to six months, when stored at -80°C.

Administration of pharmacological sleep aids prior to, during and following critical illness

BACKGROUND

Sleep in the intensive care unit (ICU) is frequently disturbed and this may have a detrimental effect on recovery.

AIMS

To determine use of pharmacological sleep aids in critically ill patients prior to, during and after ICU admission.

METHODS

We conducted a single-centre period prevalence study of all adult patients admitted to a university-associated adult medical-surgical Intensive Care Unit (ICU) for more than two nights in a three-month period ending September 2019. The major outcome of interest was the proportion of ICU patients who had a pharmacological sleep aid administered prior to, during and after ICU admission. Associations of selected patient variables with sleep aid prescription in the ICU were summarized both as unadjusted univariable comparisons, and as adjusted effect estimates returned by a multivariable logistic regression model.

RESULTS

During the study period, 370 patients met all eligibility criteria. A pharmacological sleep aid was identified prior to hospital admission in 34 patients (9%) and in 62 patients (17%) during ICU admission. Of the 340 ICU survivors, 292 remained in the same hospital. Of these, 96 (33%) received a pharmacological sleep aid at least once during their post-ICU general hospital ward stay. Pre-hospital sleep aid use, male sex, longer ICU admission and higher APACHE III scores were associated with sleep aid prescription in the ICU.

CONCLUSIONS

Pharmacological sleep aids are administered frequently in the ICU with administration increasing substantially after ICU discharge. This article is protected by copyright. All rights reserved.

The use of smartphone-derived location data to evaluate participation following critical illness: A pilot observational cohort study

BACKGROUND

Disability is common following critical illness, impacting the quality of life of survivors, and is difficult to measure. 'Participation' can be quantified as involvement in life outside of their home requiring movement from their home to other locations. Participation restriction is a key element of disability, and following critical illness, participation may be diminished. It may be possible to quantify this change using pre-existing smartphone data.

OBJECTIVES

The feasibility of extracting location data from smartphones of survivors of intensive care unit (ICU) admission and assessing participation, using location-based outcomes, during recovery from critical illness was evaluated.

METHODS

Fifty consecutively admitted, consenting adult survivors of non-elective admission to ICU of greater than 48-h duration were recruited to a prospective observational cohort study where they were followed up at 3 and 6 months following discharge. The feasibility of extracting location data from survivors' smartphones and creating location-derived outcomes assessing participation was investigated over three 28-d study periods: pre-ICU admission and at 3 and 6 months following discharge. The following were calculated: time spent at home; the number of destinations visited; linear distance travelled; and two 'activity spaces', a minimum convex polygon and standard deviation ellipse.

RESULTS

Results are median [interquartile range] or n (%). The number of successful extractions was 9/50 (18%), 12/39 (31%), and 13/33 (39%); the percentage of time spent at home was 61 [56-68]%, 77 [66-87]%, and 67 [58-77]% (P = 0.16); the number of destinations visited was 34 [18-64], 38 [22-63], and 65 [46-88] (P = 0.02); linear distance travelled was 367 [56-788], 251 [114-323], and 747 [326-933] km over 28 d (P = 0.02), pre-ICU admission and at 3 and 6 months following ICU discharge, respectively. Activity spaces were successfully created.

CONCLUSION

Limited smartphone ownership, missing data, and time-consuming data extraction limit current implementation of mass extraction of location data from patients' smartphones to aid prognostication or measure outcomes. The number of journeys taken and the linear distance travelled increased between 3 and 6 months, suggesting participation may improve over time.

A multicenter randomized clinical trial of pharmacological vitamin B1 administration to critically ill patients who develop hypophosphatemia during enteral nutrition (The THIAMINE 4 HYPOPHOSPHATEMIA trial)

BACKGROUND

Hypophosphatemia may be a useful biomarker to identify thiamine deficiency in critically ill enterally-fed patients. The objective was to determine whether intravenous thiamine affects blood lactate, biochemical and clinical outcomes in this group.

METHOD

This randomized clinical trial was conducted across 5 Intensive Care Units. Ninety critically ill adult patients with a serum phosphate ≤0.65 mmol/L within 72 h of commencing enteral nutrition were randomized to intravenous thiamine (200 mg every 12 h for up to 14 doses) or usual care (control). The primary outcome was blood lactate over time and data are median [IQR] unless specified.

RESULTS

Baseline variables were well balanced (thiamine: lactate 1.2 [1.0, 1.6] mmol/L, phosphate 0.56 [0.44, 0.64] mmol/L vs. control: lactate 1.0 [0.8, 1.3], phosphate 0.54 [0.44, 0.61]). Patients randomized to the intervention received a median of 11 [7.5, 13.5] doses for a total of 2200 [1500, 2700] mg of thiamine. Blood lactate over the entire 7 days of treatment was similar between groups (mean difference = -0.1 (95 % CI -0.2 to 0.1) mmol/L; P = 0.55). The percentage change from lactate pre-randomization to T = 24 h was not statistically different (thiamine: -32 (-39, -26) vs. control: -24 (-31, -16) percent, P = 0.09). Clinical outcomes were not statistically different (days of vasopressor administration: thiamine 2 [1, 4] vs. control 2 [0, 5.5] days; P = 0.37, and deaths 9 (21 %) vs. 5 (11 %); P = 0.25).

CONCLUSIONS

In critically ill enterally-fed patients who developed hypophosphatemia, intravenous thiamine did not cause measurable differences in blood lactate or clinical outcomes.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry (ACTRN12619000121167).

A microcosting analysis of ICU expenditure in the interval between brain death and organ donation

Objective: The cost of providing care in an intensive care unit (ICU) after brain death to facilitate organ donation is unknown. The objective of this study was to estimate expenditure for the care delivered in the ICU between the diagnosis of brain death and subsequent organ donation. Design: Cohort study of direct and indirect costs using bottom-up and top-down microcosting techniques. Setting: Single adult ICU in Australia. Participants: All patients who met criteria for brain death and proceeded to organ donation during a 13-month period between 1 January 2018 and 31 January 2019. Main outcome measures: A comprehensive cost estimate for care provided in the ICU from determination of brain death to transfer to theatre for organ donation. Results: Forty-five patients with brain death became organ donors during the study period. The mean duration of postdeath care in the ICU was 37.9 hours (standard deviation [SD], 16.5) at a mean total cost of $7520 (SD, $3136) per donor. ICU staff salaries were the greatest contributor to total costs, accounting for a median proportion of 0.72 of total expenditure (interquartile range, 0.68-0.75). Conclusions: Substantial costs are incurred in ICU for the provision of patient care in the interval between brain death and organ donation.

The impact of bereavement support on psychological distress in family members: a systematic review and meta-analysis

Background: Persistent psychological distress occurs frequently in family members of patients who die in an intensive care unit (ICU). Objective: To determine the effectiveness of bereavement interventions in reducing persisting psychological distress in bereaved family members after death in an adult ICU. Design: Systematic review and meta-analysis of studies that assessed the effect of bereavement interventions on persisting psychological distress in bereaved family members of ICU patients. Data sources: MEDLINE and APA PsycInfo databases were searched until April 2020. Review methods: Two of us independently screened titles and abstracts of identified studies, and then completed full text evaluation of selected studies. We assessed risk of bias using version 2 of the Cochrane risk-of-bias tool for randomised trials and the Newcastle-Ottawa Scale, which is designed to assess the quality of non-randomised studies in meta-analyses. We also used random effects meta-analysis to assess the effect of various interventions on total Hospital Anxiety and Depression Scale (HADS) scores. Results: From 664 citations, five studies were included - three multicentre randomised clinical trials and two single centre observational studies. Three studies tested the intervention of written bereavement support materials and two studies used narration of family members' experiences in the ICU. All studies reported HADS scores. Scores for Impact of Event Scale, Impact of Event Scale-Revised and Inventory of Complicated Grief were measured in some but not all studies. There was no effect of an intervention on HADS scores (weighted mean difference, -0.79 [95% confidence interval, -3.81 to 2.23]; I2 = 65.8%). Conclusions: Owing to limited data, and clinical and statistical heterogeneity, there is considerable uncertainty regarding whether bereavement support strategies reduce, increase or have no effect on psychological distress in bereaved family members.

Pharmacological Management of Paroxysmal Sympathetic Hyperactivity: A Scoping Review

Paroxysmal sympathetic hyperactivity (PSH) occurs in ∼10% of patients following acute severe brain injury. While PSH is associated with worse outcomes, there are no clinical practice guidelines to inform treatment. We aimed to systematically review the literature on the pharmacological management of PSH. MEDLINE, Embase, and Cochrane library databases were searched from inception to August 2020. Eligible studies met the following criteria: 1) randomized controlled trials, non-randomized controlled trials (case control or controlled cohort), observational studies, case series, and case reports; 2) study population of adult and pediatric patients; 3) exposure to an acute neurological insult complicated by PSH (or historic synonym); 4) description of pharmacological treatment of PSH. Our search retrieved 2729 citations with 83 articles assessed for inclusion. After full text extraction, 56 manuscripts inclusive of 459 patients met eligibility criteria. We identified 31 case reports, 15 case series (152 patients), seven retrospective case control or cohort studies (212 patients), and three prospective observational studies (52 patients). Traumatic brain injury was the most common precipitating insult (407 patients), followed by hypoxic encephalopathy (72 patients) and intracranial hemorrhage (10 patients). There were 48 drugs from 22 classes prescribed for the management of PSH. The most frequently prescribed agents were benzodiazepines, β-blockers, opioids, α-2 agonists, and baclofen. However, route and dose of drug and subsequent outcome were inconsistently reported, such that no summary was possible. While a wide variety of drugs have been reported to treat PSH, there is a lack of even moderate-quality evidence to inform clinical decision making.

Effects of Standard vs Energy-Dense Formulae on Gastric Retention, Energy Delivery, and Glycemia in Critically Ill Patients

BACKGROUND

Energy-dense formulae are often provided to critically ill patients with enteral feed intolerance with the aim of increasing energy delivery, yet the effect on gastric emptying is unknown. The rate of gastric emptying of a standard compared with an energy-dense formula was quantified in critically ill patients.

METHODS

Mechanically ventilated adults were randomized to receive radiolabeled intragastric infusions of 200 mL standard (1 kcal/mL) or 100 mL energy-dense (2 kcal/mL) enteral formulae on consecutive days in this noninferiority, blinded, crossover trial. The primary outcome was scintigraphic measurement of gastric retention (percentage at 120 minutes). Other measures included area under the curve (AUC) for gastric retention and intestinal energy delivery (calculated from gastric retention of formulae over time), blood glucose (peak and AUC), and intestinal glucose absorption (using 3-O-methyl-D-gluco-pyranose [3-OMG] concentrations). Comparisons were undertaken using paired mixed-effects models. Data presented are mean ± SE.

RESULTS

Eighteen patients were studied (male/female, 14:4; age, 55.2 ± 5.3 years). Gastric retention at 120 minutes was greater with the energy-dense formula (standard, 17.0 ± 5.9 vs energy-dense, 32.5 ± 7.1; difference, 12.7% [90% confidence interval, 0.8%-30.1%]). Energy delivery (AUC₁₂₀ , 13,038 ± 1119 vs 9763 ± 1346 kcal/120 minutes; P = 0.057), glucose control (peak glucose, 10.1 ± 0.3 vs 9.7 ± 0.3 mmol/L, P = 0.362; and glucose AUC₁₂₀ 8.7 ± 0.3 vs 8.5 ± 0.3 mmol/L.120 minutes, P = 0.661), and absorption (3-OMG AUC₁₂₀ , 38.5 ± 4.0 vs 35.7 ± 4.0 mmol/L.120 minutes; P = .508) were not improved with the energy-dense formula.

CONCLUSION

In critical illness, administration of an energy-dense formula does not reduce gastric retention, increase energy delivery to the small intestine, or improve glucose absorption or glucose control; instead, there is a signal for delayed gastric emptying.

Nocturnal Hypoglycemia in Patients With Diabetes Discharged From ICUs: A Prospective Two-Center Cohort Study

OBJECTIVES

There is very limited information about glycemic control after discharge from the ICU. The aims of this study were to evaluate the prevalence of hypoglycemia in ICU survivors with type-2 diabetes and determine whether hypoglycemia is associated with cardiac arrhythmias.

DESIGN

Prospective, observational, two-center study. Participants underwent up to 5 days of simultaneous blinded continuous interstitial glucose monitoring and ambulatory 12-lead electrocardiogram monitoring immediately after ICU discharge during ward-based care. Frequency of arrhythmias, heart rate variability, and cardiac repolarization markers were compared between hypoglycemia (interstitial glucose ≤ 3.5 mmol/L) and euglycemia (5-10 mmol/L) matched for time of day.

SETTING

Mixed medical-surgical ICUs in two geographically distinct university-affiliated hospitals.

PATIENTS

Patients with type-2 diabetes who were discharged from ICU after greater than or equal to 24 hours with greater than or equal to one organ failure and were prescribed subcutaneous insulin were eligible.

MEASUREMENTS AND MAIN RESULTS

Thirty-one participants (mean ± sd, age 65 ± 13 yr, glycated hemoglobin 64 ± 22 mmol/mol) were monitored for 101 ± 32 hours post-ICU (total 3,117 hr). Hypoglycemia occurred in 12 participants (39%; 95% CI, 22-56%) and was predominantly nocturnal (40/51 hr) and asymptomatic (25/29 episodes). Participants experiencing hypoglycemia had 2.4 ± 0.7 discrete episodes lasting 45 minutes (interquartile range, 25-140 min). Glucose nadir was less than or equal to 2.2 mmol/L in 34% of episodes. The longest episode of nocturnal hypoglycemia was 585 minutes with glucose nadir less than 2.2 mmol/L. Simultaneous electrocardiogram and continuous interstitial glucose monitoring recordings were obtained during 44 hours of hypoglycemia and 991 hours of euglycemia. Hypoglycemia was associated with greater risk of bradycardia but did not affect atrial or ventricular ectopics, heart rate variability, or cardiac repolarization.

CONCLUSIONS

In ICU survivors with insulin-treated type-2 diabetes, hypoglycemia occurs frequently and is predominantly nocturnal, asymptomatic, and prolonged.