Prolonged acute care and post-acute care admission and recovery of physical function in survivors of acute respiratory failure: a secondary analysis of a randomized controlled trial

Outcome Measures to Evaluate Functional Recovery in Survivors of Respiratory Failure: A Scoping Review

BACKGROUND

Respiratory failure is a life-threatening condition affecting millions of individuals in the United States annually. Survivors experience persistent functional impairments, decreased quality of life, and cognitive impairments. However, no established standard exists for measuring functional recovery among survivors of respiratory failure.

RESEARCH QUESTION

What outcomes are being used to measure and characterize functional recovery among survivors of respiratory failure?

STUDY DESIGN AND METHODS

In this scoping review, we developed a review protocol following International Prospective Register of Systematic Reviews (PROSPERO) guidelines. Two independent reviewers assessed titles and abstracts, followed by full-text review. Articles were included if study participants were aged 18 years or older, survived a hospitalization for acute respiratory failure, and received invasive mechanical ventilation as an intervention; identified function or functional recovery after respiratory failure as a study outcome; were peer-reviewed; and used any type of quantitative study design.

RESULTS

We reviewed 5,873 abstracts and identified 56 eligible articles. Among these articles, 28 distinct measures were used to assess functional recovery among survivors, including both performance-based measures (n = 8) and self-reported and proxy-reported measures (n = 20). Before 2019, 12 of the 28 distinct outcome measures (43%) were used, whereas 25 distinct measures (89%) were used from 2019 through 2024. The 6-min walk test appeared most frequently (46%) across the studies, and only 34 of 56 studies measured outcomes ≥ 6 months after discharge or study enrollment.

INTERPRETATION

Heterogeneity exists in how functional recovery is measured among survivors of respiratory failure, which highlights a need to establish a gold standard to ensure effective and consistent measurement. CHEST Critical Care 2024; 2(3):100084.

Responsiveness of Critically Ill Adults With Multimorbidity to Rehabilitation Interventions: A Patient-Level Meta-Analysis Using Individual Pooled Data From Four Randomized Trials

OBJECTIVE

To explore if patient characteristics (pre-existing comorbidity, age, sex, and illness severity) modify the effect of physical rehabilitation (intervention vs control) for the coprimary outcomes health-related quality of life (HRQoL) and objective physical performance using pooled individual patient data from randomized controlled trials (RCTs).

DATA SOURCES

Data of individual patients from four critical care physical rehabilitation RCTs.

STUDY SELECTION

Eligible trials were identified from a published systematic review.

DATA EXTRACTION

Data sharing agreements were executed permitting transfer of anonymized data of individual patients from four trials to form one large, combined dataset. The pooled trial data were analyzed with linear mixed models fitted with fixed effects for treatment group, time, and trial.

DATA SYNTHESIS

Four trials contributed data resulting in a combined total of 810 patients (intervention n = 403, control n = 407). After receiving trial rehabilitation interventions, patients with two or more comorbidities had HRQoL scores that were significantly higher and exceeded the minimal important difference at 3 and 6 months compared with the similarly comorbid control group (based on the Physical Component Summary score (Wald test p = 0.041). Patients with one or no comorbidities who received intervention had no HRQoL outcome differences at 3 and 6 months when compared with similarly comorbid control patients. No patient characteristic modified the physical performance outcome in patients who received physical rehabilitation.

CONCLUSIONS

The identification of a target group with two or more comorbidities who derived benefits from the trial interventions is an important finding and provides direction for future investigations into the effect of rehabilitation. The multimorbid post-ICU population may be a select population for future prospective investigations into the effect of physical rehabilitation.

Exercise for acutely hospitalised older medical patients

BACKGROUND

Approximately 30% of hospitalised older adults experience hospital-associated functional decline. Exercise interventions that promote in-hospital activity may prevent deconditioning and thereby maintain physical function during hospitalisation. This is an update of a Cochrane Review first published in 2007.

OBJECTIVES

To evaluate the benefits and harms of exercise interventions for acutely hospitalised older medical inpatients on functional ability, quality of life (QoL), participant global assessment of success and adverse events compared to usual care or a sham-control intervention.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was May 2021.

SELECTION CRITERIA

We included randomised or quasi-randomised controlled trials evaluating an in-hospital exercise intervention in people aged 65 years or older admitted to hospital with a general medical condition. We excluded people admitted for elective reasons or surgery.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our major outcomes were 1. independence with activities of daily living; 2. functional mobility; 3. new incidence of delirium during hospitalisation; 4. QoL; 5. number of falls during hospitalisation; 6. medical deterioration during hospitalisation and 7. participant global assessment of success. Our minor outcomes were 8. death during hospitalisation; 9. musculoskeletal injuries during hospitalisation; 10. hospital length of stay; 11. new institutionalisation at hospital discharge; 12. hospital readmission and 13. walking performance. We used GRADE to assess certainty of evidence for each major outcome. We categorised exercise interventions as: rehabilitation-related activities (interventions designed to increase physical activity or functional recovery, but did not follow a specified exercise protocol); structured exercise (interventions that included an exercise intervention protocol but did not include progressive resistance training); and progressive resistance exercise (interventions that included an element of progressive resistance training).

MAIN RESULTS

We included 24 studies (nine rehabilitation-related activity interventions, six structured exercise interventions and nine progressive resistance exercise interventions) with 7511 participants. All studies compared exercise interventions to usual care; two studies, in addition to usual care, used sham interventions. Mean ages ranged from 73 to 88 years, and 58% of participants were women. Several studies were at high risk of bias. The most common domain assessed at high risk of bias was measurement of the outcome, and five studies (21%) were at high risk of bias arising from the randomisation process. Exercise may have no clinically important effect on independence in activities of daily living at discharge from hospital compared to controls (16 studies, 5174 participants; low-certainty evidence). Five studies used the Barthel Index (scale: 0 to 100, higher scores representing greater independence). Mean scores at discharge in the control groups ranged from 42 to 96 points, and independence in activities of daily living was 1.8 points better (0.43 worse to 4.12 better) with exercise compared to controls. The minimally clinical important difference (MCID) is estimated to be 11 points. We are uncertain regarding the effect of exercise on functional mobility at discharge from the hospital compared to controls (8 studies, 2369 participants; very low-certainty evidence). Three studies used the Short Physical Performance Battery (SPPB) (scale: 0 to 12, higher scores representing better function) to measure functional mobility. Mean scores at discharge in the control groups ranged from 3.7 to 4.9 points on the SPPB, and the estimated effect of the exercise interventions was 0.78 points better (0.02 worse to 1.57 better). A change of 1 point on the SPPB represents an MCID. We are uncertain regarding the effect of exercise on the incidence of delirium during hospitalisation compared to controls (7 trials, 2088 participants; very low-certainty evidence). The incidence of delirium during hospitalisation was 88/1091 (81 per 1000) in the control group compared with 70/997 (73 per 1000; range 47 to 114) in the exercise group (RR 0.90, 95% CI 0.58 to 1.41). Exercise interventions may result in a small clinically unimportant improvement in QoL at discharge from the hospital compared to controls (4 studies, 875 participants; low-certainty evidence). Mean QoL on the EuroQol 5 Dimensions (EQ-5D) visual analogue scale (VAS) (scale: 0 to 100, higher scores representing better QoL) ranged between 48.9 and 64.7 in the control group at discharge from the hospital, and QoL was 6.04 points better (0.9 better to 11.18 better) with exercise. A change of 10 points on the EQ-5D VAS represents an MCID. No studies measured participant global assessment of success. Exercise interventions did not affect the risk of falls during hospitalisation (moderate-certainty evidence). The incidence of falls was 31/899 (34 per 1000) in the control group compared with 31/888 (34 per 1000; range 20 to 57) in the exercise group (RR 0.99, 95% CI 0.59 to 1.65). We are uncertain regarding the effect of exercise on the incidence of medical deterioration during hospitalisation (very low-certainty evidence). The incidence of medical deterioration in the control group was 101/1417 (71 per 1000) compared with 96/1313 (73 per 1000; range 44 to 120) in the exercise group (RR 1.02, 95% CI 0.62 to 1.68). Subgroup analyses by different intervention categories and by the use of a sham intervention were not meaningfully different from the main analyses.

AUTHORS' CONCLUSIONS

Exercise may make little difference to independence in activities of daily living or QoL, but probably does not result in more falls in older medical inpatients. We are uncertain about the effect of exercise on functional mobility, incidence of delirium and medical deterioration. Certainty of evidence was limited by risk of bias and inconsistency. Future primary research on the effect of exercise on acute hospitalisation could focus on more consistent and uniform reporting of participant's characteristics including their baseline level of functional ability, as well as exercise dose, intensity and adherence that may provide an insight into the reasons for the observed inconsistencies in findings.

Functional status recovery trajectories in hospitalised older adults with pneumonia

BACKGROUND AND OBJECTIVES

Pneumonia is associated with significant mortality and morbidity in older adults. We investigated changes in functional status over 6 months after pneumonia hospitalisation by frailty status.

METHODS AND MEASUREMENTS

This single-centre prospective cohort study enrolled 201 patients (mean age 79.4, 37.3% women) who were hospitalised with pneumonia. A deficit-accumulation frailty index (range: 0-1; robust <0.15, pre-frail 0.15-0.24, mild-to-moderately frail 0.25-0.44, severely frail ≥0.45) was calculated on admission. Functional status, defined as self-reported ability to perform 21 activities and physical tasks independently, was measured by telephone at 1, 3 and 6 months after discharge. Group-based trajectory model was used to identify functional trajectories. We examined the probability of each trajectory based on frailty levels.

RESULTS

On admission, 51 (25.4%) were robust, 43 (21.4%) pre-frail, 40 (20.0%) mild-to-moderately frail and 67 (33.3%) severely frail patients. Four trajectories were identified: excellent (14.4%), good (25.4%), poor (28.9%) and very poor (31.3%). The trajectory was more strongly correlated with frailty level on admission than pneumonia severity. The most common trajectory was excellent trajectory (59.9%) in robust patients, good trajectory (74.4%) in pre-frail patients, poor trajectory (85.0%) in mild-to-moderately frail patients and very poor trajectory (89.6%) in severely frail patients. The risk of poor or very poor trajectory from robust to severely frail patients was 11.8%, 25.6%, 92.5% and 100%, respectively.

CONCLUSIONS

Frailty was a strong determinant of lack of functional recovery over 6 months after pneumonia hospitalisation in older adults. Our results call for hospital-based and post-acute care interventions for frail patients.

Predictive variables for poor long-term physical recovery after intensive care unit stay: An exploratory study

BACKGROUND

Elucidating factors that influence physical recovery of survivors after an intensive care unit (ICU) stay is paramount in maximizing long-term functional outcomes. We examined potential predictors for poor long-term physical recovery in ICU survivors.

METHODS

Based on secondary analysis of a trial of 50 ICU patients who underwent mobilization in the ICU and were followed for one year, linear regression analysis examined the associations of exposure variables (baseline characteristics, severity of illness variables, ICU-related variables, and lengths of ICU and hospital stay), with physical recovery variables (muscle strength, exercise capacity, and self-reported physical function), measured one year after ICU discharge.

RESULTS

When the data were adjusted for age, female gender was associated with reduced muscle strength (P = .003), exercise capacity (P < .0001), and self-reported physical function (P = .01). Older age, when adjusted for gender, was associated with reduced exercise capacity (P < .001). After adjusting for gender and age, an association was observed between a lower score on one or two physical recovery variables and exposure variables, specifically, high body mass index, low functional independence, comorbidity and low self-reported physical function at baseline, muscle weakness at ICU discharge, and longer hospital stay. No adjustment was made for cumulative type I error rate due to small number of participants.

CONCLUSION

Elucidating risk factors for poor long-term physical recovery after ICU stay, including gender, may be critical if mobilization and exercise are to be prescribed expediently during and after ICU stay, to ensure maximal long-term recovery.

Searching for the Responder, Unpacking the Physical Rehabilitation Needs of Critically Ill Adults: A REVIEW

Survivors of critical illness can experience persistent deficits in physical function and poor health-related quality of life and utilize significant health care resources. Short-term improvements in these outcomes have been reported following physical rehabilitation. Safety and feasibility of delivering physical rehabilitation are established; however, low physical activity levels are observed throughout the recovery of patients. We provide examples on how physical activity may be increased through interdisciplinary models of service delivery. Recently, however, there has been an emergence of large randomized controlled trials reporting no effect on long-term patient outcomes. In this review, we use a proposed theoretical construct to unpack the findings of 12 randomized controlled trials that delivered physical rehabilitation during the acute hospital stay. We describe the search for the responder according to modifiers of treatment effect for physical function, health-related quality of life, and health care utilization outcomes. In addition, we propose tailoring and timing physical rehabilitation interventions to patient subgroups that may respond differently based on their impairments and perpetuating factors that hinder recovery. We examine in detail the timing, components, and dosage of the trial intervention arms. We also describe facilitators and barriers to physical rehabilitation implementation and factors that are influential in recovery from critical illness. Through this theoretical construct, we anticipate that physical rehabilitation programs can be better tailored to the needs of survivors to deliver appropriate interventions to patients who derive greatest benefit optimally timed in their recovery trajectory.

Physical Function Trajectories in Survivors of Acute Respiratory Failure

RATIONALE

Survivorship from critical illness has improved; however, factors mediating the functional recovery of persons experiencing a critical illness remain incompletely understood.

OBJECTIVES

To identify groups of acute respiratory failure (ARF) survivors with similar patterns of physical function recovery after discharge and to determine the characteristics associated with group membership in each physical function trajectory group.

METHODS

We performed a secondary analysis of a randomized controlled trial, using group-based trajectory modeling to identify distinct subgroups of patients with similar physical function recovery patterns after ARF. Chi-square tests and one-way analysis of variance were used to determine which variables were associated with trajectory membership. A multinomial logistic regression analysis was performed to identify variables jointly associated with trajectory group membership.

RESULTS

A total of 260 patients enrolled in a trial evaluating standardized rehabilitation therapy in patients with ARF and discharged alive (NCT00976833) were included in this analysis. Physical function was quantified using the Short Physical Performance Battery at hospital discharge and 2, 4, and 6 months after enrollment. Latent class analysis of the Short Physical Performance Battery scores identified four trajectory groups. These groups differ in both the degree and rate of physical function recovery. A multinomial logistic regression analysis was performed using covariates that have been previously identified in the literature as influencing recovery after critical illness. By multinomial logistic regression, age (P < 0.001), female sex (P = 0.001), intensive care unit (ICU) length of stay (LOS) (P = 0.003), and continuous intravenous sedation days (P = 0.004) were the variables that jointly influenced trajectory group membership. Participants in the trajectory demonstrating most rapid and complete functional recovery consisted of younger females with fewer continuous sedation days and a shorter LOS. The participant trajectory that failed to functionally recover consisted of older patients with greater sedation time and the longest LOS.

CONCLUSIONS

We identified distinct trajectories of physical function recovery after critical illness. Age, sex, continuous sedation time, and ICU length of stay impact the trajectory of functional recovery after critical illness. Further examination of these groups may assist in clinical trial design to tailor interventions to specific subgroups.

Response to physical rehabilitation and recovery trajectories following critical illness: individual participant data meta-analysis protocol

INTRODUCTION

The number of inconclusive physical rehabilitation randomised controlled trials for patients with critical illness is increasing. Evidence suggests critical illness patient subgroups may exist that benefit from targeted physical rehabilitation interventions that could improve their recovery trajectory. We aim to identify critical illness patient subgroups that respond to physical rehabilitation and map recovery trajectories according to physical function and quality of life outcomes. Additionally, the utilisation of healthcare resources will be examined for subgroups identified.

METHODS AND ANALYSIS

This is an individual participant data meta-analysis protocol. A systematic literature review was conducted for randomised controlled trials that delivered additional physical rehabilitation for patients with critical illness during their acute hospital stay, assessed chronic disease burden, with a minimum follow-up period of 3 months measuring performance-based physical function and health-related quality of life outcomes. From 2178 records retrieved in the systematic literature review, four eligible trials were identified by two independent reviewers. Principal investigators of eligible trials were invited to contribute their data to this individual participant data meta-analysis. Risk of bias will be assessed (Cochrane risk of bias tool for randomised trials). Participant and trial characteristics, interventions and outcomes data of included studies will be summarised. Meta-analyses will entail a one-stage model, which will account for the heterogeneity across and the clustering between studies. Multiple imputation using chained equations will be used to account for the missing data.

ETHICS AND DISSEMINATION

This individual participant data meta-analysis does not require ethical review as anonymised participant data will be used and no new data collected. Additionally, eligible trials were granted approval by institutional review boards or research ethics committees and informed consent was provided for participants. Data sharing agreements are in place permitting contribution of data. The study findings will be disseminated at conferences and through peer-reviewed publications.

PROSPERO REGISTRATION NUMBER

CRD42019152526.

Simple functional assessment at hospital discharge can predict long-term outcomes of ICU survivors

Recent studies showed that physical and/or neuropsychiatric impairments significantly affect long-term mortality of ICU survivors. We conducted this study to investigate that simplified measurement of physical function and level of consciousness at hospital discharge by attending nurses could predict long-term outcomes after hospital discharge. A retrospective analysis of prospectively and retrospectively collected data of 246 patients who received medical ICU treatment was conducted. We grouped patients according to physical function and level of consciousness measured by the simplified method at hospital discharge as follow; group A included patients with alert mental and capable of walking or moving by wheel chairs; group B included those with alert mental and bed-ridden status; and Group C included those with confused mental and bed-ridden status. The two-year survival rate after hospital discharge was compared. Of 246 patients, 157 patients were included in the analysis and there were 103 survivors after two-year follow up. Compared to non-survivors, survivors were more likely to be younger (P = 0.026) and have higher body mass index (P = 0.019) and no malignant disease (P = 0.001). There were no statistically significant differences in treatment modalities including medication, use of medical devices, and physical therapy between the survivors and non-survivors. The analysis showed significant differences in survival between the groups classified by physical function (P < 0.001) and level of consciousness (P < 0.01). Multivariate analysis showed that survival rate was significantly lower among the patients in group C than in those in group B or group A (P < 0.001). Simplified method to assess physical function and level of consciousness at hospital discharge can predict long-term outcomes of medical ICU survivors.

Can the critically ill patient generate sufficient energy to facilitate exercise in the ICU?

PURPOSE OF REVIEW

Trials of physical rehabilitation post critical illness have yet to deliver improved health-related quality of life in critical illness survivors. Muscle mass and strength are lost rapidly in critical illness and a proportion of patients continue to do so resulting in increased mortality and functional disability. Addressing this issue is therefore fundamental for recovery from critical illness.

RECENT FINDINGS

Altered mitochondrial function occurs in the critically ill and is likely to result in decreased adenosine tri-phosphate (ATP) production. Muscle contraction is a process that requires ATP. The metabolic demands of exercise are poorly understood in the ICU setting. Recent research has highlighted that there is significant heterogeneity in energy requirements between critically ill individuals undertaking the same functional activities, such as sit-to-stand. Nutrition in the critically ill is currently thought of in terms of carbohydrates, fat and protein. It may be that we need to consider nutrition in a more contextual manner such as energy generation or management of protein homeostasis.

SUMMARY

Current nutritional support practices in critically ill patients do not lead to improvements in physical and functional outcomes, and it may be that alternative methods of delivery or substrates are needed.