Predisposing factors for critical illness polyneuromyopathy in a multidisciplinary intensive care unit

Advancing critical care recovery: The pivotal role of machine learning in early detection of intensive care unit-acquired weakness

This editorial explores the significant challenge of intensive care unit-acquired weakness (ICU-AW), a prevalent condition affecting critically ill patients, characterized by profound muscle weakness and complicating patient recovery. Highlighting the paradox of modern medical advances, it emphasizes the urgent need for early identification and intervention to mitigate ICU-AW's impact. Innovatively, the study by Wang et al is showcased for employing a multilayer perceptron neural network model, achieving high accuracy in predicting ICU-AW risk. This advancement underscores the potential of neural network models in enhancing patient care but also calls for continued research to address limitations and improve model applicability. The editorial advocates for the development and validation of sophisticated predictive tools, aiming for personalized care strategies to reduce ICU-AW incidence and severity, ultimately improving patient outcomes in critical care settings.

Safety and Feasibility of Neuromuscular Electrical Stimulation in Patients with Extracorporeal Membrane Oxygenation

Background/Objectives: The aim of this study was to investigate the feasibility and safety of neuromuscular electrical stimulation (NMES) in patients on extracorporeal membrane oxygenation (ECMO) and thoroughly assess any potential adverse events. Methods: We conducted a prospective observational study assessing safety and feasibility, including 16 ICU patients on ECMO support who were admitted to the cardiac surgery ICU from January 2022 to December 2023. The majority of patients were females (63%) on veno-arterial (VA)-ECMO (81%), while the main cause was cardiogenic shock (81%) compared to respiratory failure. Patients underwent a 45 min NMES session while on ECMO support that included a warm-up phase of 5 min, a main phase of 35 min, and a recovery phase of 5 min. NMES was implemented on vastus lateralis, vastus medialis, gastrocnemius, and peroneus longus muscles of both lower extremities. Two stimulators delivered biphasic, symmetric impulses of 75 Hz, with a 400 μsec pulse duration, 5 sec on (1.6 sec ramp up and 0.8 sec ramp down) and 21 sec off. The intensity levels aimed to cause visible contractions and be well tolerated. Primary outcomes of this study were feasibility and safety, evaluated by whether NMES sessions were successfully achieved, and by any adverse events and complications. Secondary outcomes included indices of rhabdomyolysis from biochemical blood tests 24 h after the application of NMES. Results: All patients successfully completed their NMES session, with no adverse events or complications. The majority of patients achieved type 4 and 5 qualities of muscle contraction. Conclusions: NMES is a safe and feasible exercise methodology for patients supported with ECMO.

Assessing the Diagnostic Efficacy of Handgrip Dynamometry and Diaphragmatic Ultrasound in Intensive Care Unit-Acquired Weakness

Objective

The aim of this study is to examine the diagnostic significance of using handgrip dynamometry and diaphragmatic ultrasound in intensive care unit-acquired weakness (ICU-AW).

Methods

This study included patients who received mechanical ventilation in the ICU at the Fourth Hospital of Hebei Medical University from July to December 2020. We collected comprehensive demographic data and selected conscious patients for muscle strength and ICU-AW assessments. The evaluation comprised grip strength measurement and bedside ultrasound for diaphragmatic excursion (DE) and thickening fraction (DTF). Results were documented for comparative analysis between patient groups, focusing on the diagnostic efficacy of grip strength, DE, DTF, and their combined application in diagnosing ICU-AW.

Results

A total of 95 patients were initially considered for inclusion in this study. Following the exclusion of 20 patients, a final cohort of 75 patients were enrolled, comprising of 32 patients (42.6%) diagnosed with ICU-AW and 43 patients (57.4%) classified as non-ICU-AW. Comparative analysis revealed that grip strength, DE, and DTF were significantly lower in the ICU-AW group (P < 0.05). Subgroup analysis specific to male patients demonstrated a noteworthy decrease in grip strength, DE, and DTF within the ICU-AW group (P < 0.05). Receiver operating characteristic curve analysis indicated statistically significant diagnostic value for ICU-AW with grip strength, DE, DTF, and grip strength and diaphragmatic ultrasound (P < 0.01). Furthermore, it was observed that the amalgamation of grip strength and diaphragmatic ultrasound significantly enhanced the diagnostic accuracy of ICU-AW in patients who are critically ill.

Conclusion

Grip strength, DE, DTF, and the combined use of grip strength with diaphragm ultrasound demonstrated diagnostic efficacy in ICU-AW. Notably, the integration of grip strength with diaphragm ultrasound exhibited a heightened capacity to enhance the diagnostic value specifically in patients diagnosed who are critically ill with ICU-AW.

Stress hyperglycaemia following trauma - a survival benefit or an outcome detriment?

PURPOSE OF REVIEW

Stress hyperglycaemia occur often in critically injured patients. To gain new consideration about it, this review compile current as well as known immunological and biochemical findings about causes and emergence.

RECENT FINDINGS

Glucose is the preferred energy substrate for fending immune cells, reparative tissue and the cardiovascular system following trauma. To fulfil these energy needs, the liver is metabolically reprogrammed to rebuild glucose from lactate and glucogenic amino acids (hepatic insulin resistance) at the expenses of muscles mass and - to a less extent - fat tissue (proteolysis, lipolysis, peripheral insulin resistance). This inevitably leads to stress hyperglycaemia, which is evolutionary preserved and seems to be an essential and beneficial survival response. It is initiated by damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns (PAMPs), intensified by immune cells itself and mainly ruled by tumour necrosis factor (TNF)α and catecholamines with lactate and hypoxia inducible factor (HIF)-1α as intracellular signals and lactate as an energy shuttle. Important biochemical mechanisms involved in this response are the Warburg effect as an efficient metabolic shortcut and the extended Cori cycle.

SUMMARY

Stress hyperglycaemia is beneficial in an acute life-threatening situation, but further research is necessary, to prevent trauma patients from the detrimental effects of persisting hyperglycaemia.

Deep Machine Learning Might Aid in Combating Intensive Care Unit-Acquired Weakness

Secondary muscle weakness in critically ill patients like intensive care unit (ICU)-associated weakness is frequently noted in patients with prolonged mechanical ventilation and ICU stay. It can be a result of critical illness, myopathy, or neuropathy. Although ICU-acquired weakness (ICU-AW) has been known for a while, there is still no effective treatment for it. Therefore, prevention of ICU-AW becomes the utmost priority, and knowing the risk factors is crucial. Nevertheless, the pathophysiology and the attributing causes are complex for ICU-AW, and proper delineation and formulation of a preventive strategy from such vast, multifaceted data are challenging. Artificial intelligence has recently helped healthcare professionals understand and analyze such intricate data through deep machine learning. Hence, using such a strategy also helps in knowing the risk factors and their weight as contributors, applying them in formulating a preventive path for ICU-AW worth trials.

Effects of the High-Intensity Early Mobilization on Long-Term Functional Status of Patients with Mechanical Ventilation in the Intensive Care Unit

Objective

Intensive care unit (ICU)-acquired weakness often occurs in patients with invasive mechanical ventilation (IMV). Early active mobility may reduce ICU-acquired weakness, improve functional status, and reduce disability. The aim of this study was to investigate whether high-intensity early mobility improves post-ICU discharge functional status of IMV patients.

Methods

132 adult patients in the ICU who were undergoing IMV were randomly assigned into two groups with a ratio of 1 : 1, with one group received high-intensity early mobility (intervention group, IG), while the other group received conventional treatment (control group, CG). The functional status (Barthel Index (BI)), capacity of mobility (Perme score and ICU Mobility Scale (IMS)), muscle strength (Medical Research Council sum scores (MRC-SS)), mortality, complication, length of ICU stay, and duration of IMV were evaluated at ICU discharge or after 3-month of ICU discharge.

Results

The patient's functional status was improved (BI scores 90.6 ± 18.0 in IG vs. 77.7 ± 27.9 in CG; p=0.005), and capacity of mobility was increased (Perme score 17.6 ± 7.1 in IG vs. 12.2 ± 8.5 in CG, p < 0.001; IMS 4.7 ± 2.6 in IG vs. 3.0 ± 2.6 in CG, p < 0.001). The IG had a higher muscle strength and lower incidence of ICU-acquired weakness (ICUAW) than that in the CG. The incidence of mortality and delirium was also lower than CG at ICU discharge. However, there were no differences in terms of length of ICU stay, duration of IMV, ventilator-associated pneumonia, and venous thrombosis.

Conclusions

High-intensity early mobility improved the patient's functional status and increased capacity of mobility with IMV. The benefits to functional status remained after 3 month of ICU discharge. Other benefits included higher muscle strength, lower incidence of ICUAW, mortality, and delirium in IG.

Incidence and risk factors of peripheral nerve injuries 3 months after ICU discharge: a retrospective study comparing COVID-19 and non-COVID-19 critically ill survivors

BACKGROUND

Peripheral nerve injuries (PNI) have been associated with prone positioning (PP) in mechanically ventilated (MV) patients with COVID-19 pneumonia. The aims of this retrospective study were to describe PNI prevalence 3 months (M3) after intensive care unit (ICU) discharge, whether patients survived COVID-19 or another critical illness, and to search for risk factors of PNI.

RESULTS

A total of 55 COVID (62 [54-69] years) and 22 non-COVID (61.5 [48-71.5] years) patients were followed at M3, after an ICU stay of respectively 15 [9-26.5] and 13.5 [10-19.8] days. PNI symptoms were reported by 23/55 (42.6%) COVID-19 and 8/22 (36%) non-COVID-19 patients (p = 0.798). As the incidence of PNI was similar in both groups, the entire population was used to determine risk factors. The MV duration predicted PNI occurrence (OR (CI95%) = 1.05 (1.01-1.10), p = 0.028), but not the ICU length of stay, glucocorticoids, or inflammation biomarkers.

CONCLUSION

In the present cohort, PNI symptoms were reported in at least one-third of the ICU survivors, in similar proportion whether patients suffered from severe COVID-19 or not.

Safety and effectiveness of neuromuscular electrical stimulation in cardiac surgery: A systematic review

BACKGROUND

Lack of mobilization and prolonged stay in the intensive care unit (ICU) are major factors resulting in the development of ICU-acquired muscle weakness (ICUAW). ICUAW is a type of skeletal muscle dysfunction and a common complication of patients after cardiac surgery, and may be a risk factor for prolonged duration of mechanical ventilation, associated with a higher risk of readmission and higher mortality. Early mobilization in the ICU after cardiac surgery has been found to be low with a significant trend to increase over ICU stay and is also associated with a reduced duration of mechanical ventilation and ICU length of stay. Neuromuscular electrical stimulation (NMES) is an alternative modality of exercise in patients with muscle weakness. A major advantage of NMES is that it can be applied even in sedated patients in the ICU, a fact that might enhance early mobilization in these patients.

AIM

To evaluate safety, feasibility and effectiveness of NMES on functional capacity and muscle strength in patients before and after cardiac surgery.

METHODS

We performed a search on Pubmed, Physiotherapy Evidence Database (PEDro), Embase and CINAHL databases, selecting papers published between December 2012 and April 2023 and identified published randomized controlled trials (RCTs) that included implementation of NMES in patients before after cardiac surgery. RCTs were assessed for methodological rigor and risk of bias via the PEDro. The primary outcomes were safety and functional capacity and the secondary outcomes were muscle strength and function.

RESULTS

Ten studies were included in our systematic review, resulting in 703 participants. Almost half of them performed NMES and the other half were included in the control group, treated with usual care. Nine studies investigated patients after cardiac surgery and 1 study before cardiac surgery. Functional capacity was assessed in 8 studies via 6MWT or other indices, and improved only in 1 study before and in 1 after cardiac surgery. Nine studies explored the effects of NMES on muscle strength and function and, most of them, found increase of muscle strength and improvement in muscle function after NMES. NMES was safe in all studies without any significant complication.

CONCLUSION

NMES is safe, feasible and has beneficial effects on muscle strength and function in patients after cardiac surgery, but has no significant effect on functional capacity.

Intensive care unit-acquired weakness: Recent insights

Intensive care unit-acquired weakness (ICU-AW) is a common complication in critically ill patients and is associated with a variety of adverse outcomes. These include the need for prolonged mechanical ventilation and ICU stay; higher ICU, in-hospital, and 1-year mortality; and increased in-hospital costs. ICU-AW is associated with multiple risk factors including age, underlying disease, severity of illness, organ failure, sepsis, immobilization, receipt of mechanical ventilation, and other factors related to critical care. The pathological mechanism of ICU-AW remains unclear and may be considerably varied. This review aimed to evaluate recent insights into ICU-AW from several aspects including risk factors, pathophysiology, diagnosis, and treatment strategies; this provides new perspectives for future research.

Intensive Care Unit Hyperglycemia After Cardiac Surgery: Risk Factors and Clinical Outcomes

OBJECTIVES

Patients with hyperglycemia after cardiac surgery face increased morbidity and mortality due to postoperative complications. The main purpose of this study was to evaluate the incidence of postoperative hyperglycemia, the hyperglycemia risk factors, and its association with clinical outcomes in patients admitted to the cardiac surgery intensive care unit after cardiac surgery.

DESIGN

Prospective, observational study.

SETTING

Single-center hospital.

PARTICIPANTS

Two hundred ten consecutive postoperative cardiac surgery patients admitted to the cardiac surgery intensive care unit.

INTERVENTIONS

Patients' blood glucose levels were evaluated immediately after cardiac surgery and every 3 hours daily for 7 days or earlier upon discharge. Intravenous insulin was administered as per the institution's protocol. Perioperative predisposing risk factors for hyperglycemia and clinical outcomes were assessed.

MEASUREMENTS AND MAIN RESULTS

Postoperative hyperglycemia, defined as glucose level ≥180 mg/dL, occurred in 30% of cardiac surgery patients. Diabetes mellitus (odds ratio [OR] 6.73; 95% CI [3.2-14.3]; p < 0.001), white blood cell count (OR 1.28; 95% CI [1.1-1.4]; p < 0.001), and EuroSCORE II (OR 1.20; 95% CI [1.1-1.4]; p = 0.004) emerged as independent prognostic factors for hyperglycemia. Moreover, patients with glucose ≥180 mg/dL had higher rates of acute kidney injury (34.9% v 18.9%, p = 0.013), longer duration of mechanical ventilation (959 v 720 min, p = 0.019), and sedation (711 v 574 min, p = 0.034), and higher levels of intensive care unit (ICU)-acquired weakness (14% v 5.5%, p = 0.027) and rate of multiorgan failure (6.3% v 0.7%, p = 0.02) compared with patients with glucose levels <180 mg/dL.

CONCLUSIONS

In the intensive care unit, hyperglycemia occurs frequently in patients immediately after cardiac surgery. Diabetes, high EuroSCORE II, and preoperative leukocytosis are independent risk factors for postoperative hyperglycemia. Hyperglycemia is associated with worse clinical outcomes, including a higher rate of acute kidney injury and ICU-acquired weakness, greater duration of mechanical ventilation, and a higher rate of multiorgan failure.

Facial nerve neurographies in intensive care unit-acquired weakness

BACKGROUND

Patients with an intensive care unit-acquired weakness (ICU-AW) often present clinically with severe paresis of the limb and trunk muscles while facial muscles appear less affected. To investigate whether the facial nerves are partially spared from this condition, we performed both peripheral and cranial nerve conduction studies in critically ill patients.

METHODS

In patients requiring prolonged ICU therapy, the motor and sensory nerve conduction velocities of the peroneal, ulnar and facial nerves and the muscle action potentials of the associated muscles, as well as the orbicularis oculi reflexes were assessed shortly after admission, and on ICU days 7 and 14.

RESULTS

Eighteen patients were included in the final data analysis (average age 54.2 ± 16.8 years, 8 females). The amplitudes of the peroneal nerve compound muscle action potentials (CMAPs) were reduced in all patients at ICU days 7 and 14 (F(1.39; 23.63) = 13.85; p < 0.001). There was no similar decrease in the CMAP amplitudes of the ulnar or facial nerve. Other parameters of nerve function (latencies, sensory and motor nerve conduction velocities, sensory nerve action potentials) remained unchanged. The reproducibility of the orbicularis oculi reflex was reduced during the disease course, while its latencies did not change significantly during the disease course.

CONCLUSIONS

There is a relative preservation of CMAPs in facial and hand as opposed to foot muscles. This is compatible with the clinical observation that the facial muscles in patients with ICU-AW are less severely affected. This may be primarily a function of the nerve length, and consequently more robust trophic factors in shorter nerves. Trial registration This study was prospectively registered in the German Clinical Trial Register on April 20th 2020 (DRKS00021467).

Serum Acylcarnitines Profile in Critically Ill Survivors According to Illness Severity and ICU Length of Stay: An Observational Study

The acylcarnitine (AC) profile has been shown to be altered in survivors of a prolonged stay in intensive care unit (ICU), with higher short-chain derivates compared to reference ranges. The present study aimed at describing the AC profile of patients surviving a short ICU stay versus patients surviving a >7-day multiple organ dysfunction. Patients discharged from ICU after an elective and non-complicated cardiac surgery (CS) were recruited. For each CS, one to two adults, matched for gender and age, were recruited among patients enrolled in our post-ICU follow-up program after an ICU stay ≥7 days (PS). In both groups, the AC profile was determined during the week following ICU discharge. A total of 50 CS patients (SAPS II 23 (18-27)) survived an ICU stay of 2 (2-3) days and were matched to 85 PS patients (SAPS II 36 (28-51), p < 0.001) who survived an ICU stay of 11 (8-15.5) days. No carnitine deficiency was observed in either group. Their total AC/C0 ratio was similar: 0.355 (0.268-0.415) and 0.358 (0.289-0.417), respectively (p = 0.391). A ratio >0.4 representing a disturbed mitochondrial metabolism was observed in 26/85 (30.6%) PS patients and in 15/50 (30%) CS patients (p > 0.999). The long-chain ACs were elevated in both groups, with a greater increase in the CS group. The short-chain ACs were higher in the PS group: 1.520 (1.178-1.974) vs. 1.185 (0.932-1.895) μmol/L (p < 0.001). The role of the AC profile as potential marker of catabolism and/or mitochondrial dysfunction during the critical illness trajectory should be further investigated.

Association between neuromuscular blocking agents and the development of intensive care unit-acquired weakness (ICU-AW): A systematic review with meta-analysis and trial sequential analysis

BACKGROUND

The present study aims to review the literature and synthesize evidence concerning the effects of the use of neuromuscular blocking agents (NMBA) regarding the development of intensive care unit-acquired weakness (ICU-AW).

METHODS

This study was registered in the PROSPERO database CRD42020142916. Systematic review in PubMed, Embase, and the Cochrane Central, Randomized clinical trials (RCTs), and cohort studies with adults that reported the use of NMBA and the development of ICU-AW were included. Pre-specified subgroup analyses were performed for presence of sepsis and type of NMBA used. The quality of evidence for intervention effects was summarized. The certainty of evidence was assessed using the GRADE approach.

RESULTS

We included 30 studies, four RCTs, 21 prospective and 5 retrospective cohorts, enrolling a total of 3839 patients. Most of the included studies were observational with high heterogeneity, whereas the RCTs had a high risk of bias. The use of NMBA increased the odds of developing ICU-AW (OR = 2.77 [95% CI 1.98-3.88], I² = 62%), with low-quality of evidence. A trial sequential analysis showed the need to include 22,330 patients in order to provide evidence for either beneficial or harmful intervention effects.

CONCLUSIONS

This meta-analysis suggests that the use of NMBA might be implicated in the development of ICU-AW. However, there is not enough evidence to definitively conclude about the association between the use of NMBA and the development of ICU-AW, as these results are based mostly on observational studies with high heterogeneity.

Characterization of muscle mass, strength and mobility of critically ill patients with SARS-CoV-2 pneumonia: Distribution by sex, age, days on mechanical ventilation, and muscle weakness

Objective: Quantify and categorize by sex, age, and time spent on mechanical ventilation (MV), the decline in skeletal muscle mass, strength and mobility in critically ill patients infected with SARS-CoV-2 and requiring mechanical ventilation while at intensive care unit (ICU). Design: Prospective observational study including participants recruited between June 2020 and February 2021 at Hospital Clínico Herminda Martin (HCHM), Chillán, Chile. The thickness of the quadriceps muscle was evaluated by ultrasonography (US) at intensive care unit admission and awakening. Muscle strength and mobility were assessed, respectively, through the Medical Research Council Sum Score (MRC-SS) and the Functional Status Score for the Intensive Care Unit Scale (FSS-ICU) both at awakening and at ICU discharge. Results were categorized by sex (female or male), age (<60 years old or ≥60 years old) and time spent on MV (≤10 days or >10 days). Setting: Intensive care unit in a public hospital. Participants: 132 participants aged 18 years old or above (women n = 49, 60 ± 13 years; men n = 85, 59 ± 12 years) admitted to intensive care unit with a confirmed diagnosis of severe SARS-CoV-2 and requiring MV for more than 48 h were included in the study. Patients with previous physical and or cognitive disorders were excluded. Interventions: Not applicable. Results: Muscle thickness have significantly decreased during intensive care unit stay, vastus intermedius (-11%; p = 0.025), rectus femoris (-20%; p < 0.001) and total quadriceps (-16%; p < 0.001). Muscle strength and mobility were improved at intensive care unit discharge when compared with measurements at awakening in intensive care unit (time effect, p < 0.001). Patients ≥60 years old or on MV for >10 days presented greater muscle loss, alongside with lower muscle strength and mobility. Conclusion: Critically ill patients infected with SARS-CoV-2 and requiring MV presented decreased muscle mass, strength, and mobility during their intensive care unit stay. Factors associated with muscle mass, such as age >60 years and >10 days of MV, exacerbated the critical condition and impaired recovery.

The rate and assessment of muscle wasting during critical illness: a systematic review and meta-analysis

BACKGROUND

Patients with critical illness can lose more than 15% of muscle mass in one week, and this can have long-term detrimental effects. However, there is currently no synthesis of the data of intensive care unit (ICU) muscle wasting studies, so the true mean rate of muscle loss across all studies is unknown. The aim of this project was therefore to systematically synthetise data on the rate of muscle loss and to identify the methods used to measure muscle size and to synthetise data on the prevalence of ICU-acquired weakness in critically ill patients.

METHODS

We conducted a systematic literature search of MEDLINE, PubMed, AMED, BNI, CINAHL, and EMCARE until January 2022 (International Prospective Register of Systematic Reviews [PROSPERO] registration: CRD420222989540. We included studies with at least 20 adult critically ill patients where the investigators measured a muscle mass-related variable at two time points during the ICU stay. We followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and assessed the study quality using the Newcastle-Ottawa Scale.

RESULTS

Fifty-two studies that included 3251 patients fulfilled the selection criteria. These studies investigated the rate of muscle wasting in 1773 (55%) patients and assessed ICU-acquired muscle weakness in 1478 (45%) patients. The methods used to assess muscle mass were ultrasound in 85% (n = 28/33) of the studies and computed tomography in the rest 15% (n = 5/33). During the first week of critical illness, patients lost every day -1.75% (95% CI -2.05, -1.45) of their rectus femoris thickness or -2.10% (95% CI -3.17, -1.02) of rectus femoris cross-sectional area. The overall prevalence of ICU-acquired weakness was 48% (95% CI 39%, 56%).

CONCLUSION

On average, critically ill patients lose nearly 2% of skeletal muscle per day during the first week of ICU admission.

A systematic review and meta-analysis of risk factors for intensive care unit acquired weakness

BACKGROUND

The aim of this meta-analysis is to systematically evaluate and summarize the risk factors of intensive care unit acquired weakness (ICU-AW), to provide evidence-based evidence for the formulation of prevention strategies for ICU-AW.

METHODS

PubMed, EMBASE, Web of Science, CBM (China Biology Medicine, China), Chinese National Knowledge Infrastructure, Chinese WANFANG, and VIP will be searched to define relevant risk factors for ICU-AW. The databases search period is from January 1, 2005 to August 13, 2021. The Newcastle Ottawa Scale (NOS) is used to evaluate the quality of the included studies. RevMan 5.3 analysis software will be used for meta-analysis.

RESULTS

This systematic review and meta-analysis included a total of 12 cohort studies, including 9 international journals and 3 Chinese journals, with a total of 1950 patients, of which 856 had ICU-AW. The results showed that the significant risk factors for ICU-AW included female (odds ratio [OR] = 1.34, 95% confidence interval [CI]: 1.06-1.71; P = .02), mechanical ventilation days (OR = 3.04, 95% CI: 1.82-4.26; P < .00001), age (OR = 6.33, 95% CI: 5.05-7.61; P < .00001), length of intensive care unit (ICU) stay (OR = 3.78, 95% CI: 2.06-5.51; P < .0001), infectious disease (OR = 1.67, 95% CI: 1.20-2.33; P = .002), renal replacement therapy (OR = 1.59, 95% CI: 1.11-2.28; P = .01), use of aminoglucoside drugs (OR = 2.51, 95% CI: 1.54-4.08; P = .0002), sepsis related organ failure assessment (SOFA) score (OR = 1.07, 95% CI: 0.24-1.90; P = .01), hyperglycemia (OR = 2.95, 95% CI: 1.70-5.11; P = .0001).

CONCLUSION

This meta-analysis provides comprehensive evidence-based on the assessment of the risk factors for ICU-AW, their multifactorial etiology was confirmed. This study indicated that female, mechanical ventilation days, age, length of ICU stay, infectious disease, renal replacement therapy, use of aminoglucoside drugs, SOFA score, and hyperglycemia are independent risk factors for ICU-AW. We have not found consistent evidence that corticosteroids, neuromuscular blockers, sepsis have any effect on ICU-AW risk.

Multimodal assessment of intensive care unit-acquired weakness in severe stroke patients

BACKGROUND

Intensive care unit-acquired weakness (ICUAW) defines generalized muscle weakness seen in critically ill patients in the absence of other causative factors. Herein, we aimed to evaluate ICUAW in stroke patients by electrodiagnostic testing, histopathology, and assessment of respiratory complex activities (RCA), to define the frequency of ICUAW in this patient group, and to reach new parameters for early prediction and diagnosis.

METHODS

We prospectively recruited twenty-four severe acute stroke patients during a sixteen-month period. In addition to serial nerve conduction studies (NCS), we performed muscle biopsy and RCA analysis on the non-paretic side when ICUAW developed. Patients undergoing orthopedic surgery without metabolic and neuromuscular diseases constituted the control group for RCA. Survival and longitudinal data were analyzed by joint modeling to determine the relationship between electrophysiological parameters and ICUAW diagnosis.

RESULTS

Eight patients (33%) developed ICUAW, and six of them within the first two weeks. Extensor digitorum brevis, abductor digiti minimi (ADM), rectus femoris and vastus medialis (VM) compound muscle action potential (CMAP) amplitudes showed a significant decrease in the ICUAW group. VM CMAP amplitude (BIC = 358.1574) and ADM CMAP duration (BIC = 361.1028) were the best-correlated parameters with ICUAW diagnosis. The most informative electrophysiological findings during the entire study were obtained within the first 11 days. Muscle biopsies revealed varying degrees of type 2 fiber atrophy. Complex I (p = 0.003) and IV (p = 0.018) activities decreased in patients with ICUAW compared to controls.

CONCLUSION

VM CMAP amplitude and ADM CMAP duration correlate well with ICUAW diagnosis, and may aid in the early diagnosis.

Development and early diagnosis of critical illness myopathy in COVID-19 associated acute respiratory distress syndrome

BACKGROUND

The COVID-19 pandemic has greatly increased the incidence and clinical importance of critical illness myopathy (CIM), because it is one of the most common complications of modern intensive care medicine. Current diagnostic criteria only allow diagnosis of CIM at an advanced stage, so that patients are at risk of being overlooked, especially in early stages. To determine the frequency of CIM and to assess a recently proposed tool for early diagnosis, we have followed a cohort of COVID-19 patients with acute respiratory distress syndrome and compared the time course of muscle excitability measurements with the definite diagnosis of CIM.

METHODS

Adult COVID-19 patients admitted to the Intensive Care Unit of the University Hospital Bern, Switzerland requiring mechanical ventilation were recruited and examined on Days 1, 2, 5, and 10 post-intubation. Clinical examination, muscle excitability measurements, medication record, and laboratory analyses were performed on all study visits, and additionally nerve conduction studies, electromyography and muscle biopsy on Day 10. Muscle excitability data were compared with a cohort of 31 age-matched healthy subjects. Diagnosis of definite CIM was made according to the current guidelines and was based on patient history, results of clinical and electrophysiological examinations as well as muscle biopsy.

RESULTS

Complete data were available in 31 out of 44 recruited patients (mean [SD] age, 62.4 [9.8] years). Of these, 17 (55%) developed CIM. Muscle excitability measurements on Day 10 discriminated between patients who developed CIM and those who did not, with a diagnostic precision of 90% (AUC 0.908; 95% CI 0.799-1.000; sensitivity 1.000; specificity 0.714). On Days 1 and 2, muscle excitability parameters also discriminated between the two groups with 73% (AUC 0.734; 95% CI 0.550-0.919; sensitivity 0.562; specificity 0.857) and 82% (AUC 0.820; CI 0.652-0.903; sensitivity 0.750; specificity 0.923) diagnostic precision, respectively. All critically ill COVID-19 patients showed signs of muscle membrane depolarization compared with healthy subjects, but in patients who developed CIM muscle membrane depolarization on Days 1, 2 and 10 was more pronounced than in patients who did not develop CIM.

CONCLUSIONS

This study reports a 55% prevalence of definite CIM in critically ill COVID-19 patients. Furthermore, the results confirm that muscle excitability measurements may serve as an alternative method for CIM diagnosis and support its use as a tool for early diagnosis and monitoring the development of CIM.

Critical Illness Myopathy: Diagnostic Approach and Resulting Therapeutic Implications

Purpose of review

Critical illness myopathy (CIM) is a common neuro-muscular complication of intensive care treatment associated with increased morbidity and mortality. The current guidelines for diagnosis include clinical and electrophysiological criteria as well as a muscle biopsy, and allow diagnosis only at an advanced stage of the disease. To date, there is no treatment for CIM available, apart from symptomatic and rehabilitative interventions. In this review, we discuss different diagnostic approaches and describe new treatment possibilities for CIM.

Recent findings

Of the diagnostic approaches evaluated, a new electrophysiological technique for measuring muscle excitability has the greatest potential to allow earlier diagnosis of CIM than the current guidelines do and thereby may facilitate the conduction of future pathophysiological and therapeutic studies. Although clinical trials are still lacking, in animal models, BGP-15, vamorolone, and ruxolitinib have been shown to have anti-inflammatory effects, to reduce muscle wasting and to improve muscle function and survival.

Summary

In recent years, promising methods for early and confirmatory diagnosis of CIM have been developed, but still need validation. Experimental studies on novel pharmacological interventions show promising results in terms of preventive CIM treatments, but future clinical studies will be needed to study the effectiveness and safety of these drugs.

Intensive Care Unit-Acquired Weakness in Patients With COVID-19: Occurrence and Associated Factors

OBJECTIVE

The primary objective of this study was to identify the occurrence and factors associated with intensive care unit (ICU)-acquired weakness (ICUAW) in patients with COVID-19. Secondarily, we monitored the evolution of muscle strength and mobility among individuals with ICUAW and those without ICUAW and the association of these variables with length of stay, mechanical ventilation (MV), and other clinical variables.

METHODS

In this prospective observational study, individuals admitted to the ICU for >72 hours with COVID-19 were evaluated for muscle strength and mobility at 3 times: when being weaned from ventilatory support, discharged from the ICU, and discharged from the hospital. Risk factors for ICUAW were monitored.

RESULTS

The occurrences of ICUAW at the 3 times evaluated among the 75 patients included were 52%, 38%, and 13%. The length of the ICU stay (29.5 [IQR = 16.3-42.5] vs 11 [IQR = 6.5-16] days), the length of the hospital stay (43.5 [IQR = 22.8-55.3] vs 16 [IQR = 12.5-24] days), and time on MV (25.5 [IQR = 13.8-41.3] vs 10 [IQR = 5-22.5] days) were greater in patients with ICUAW. Muscle strength and mobility were lower at all times assessed in patients with ICUAW. Bed rest time for all patients (relative risk = 1.14; 95% CI = 1.02 to 1.28) and use of corticosteroids (relative risk = 1.01; 95% CI = 1.00 to 1.03) for those who required MV were factors independently associated with ICUAW. Muscle strength was found to have a positive correlation with mobility and a negative correlation with lengths of stay in the ICU and hospital and time on MV.

CONCLUSION

The occurrence of ICUAW was high on patients' awakening in the ICU but decreased throughout hospitalization; however, strength and mobility remained compromised at hospital discharge. Bed rest time and use of corticosteroids (for those who needed MV) were factors independently associated with ICUAW in patients with COVID-19.

IMPACT

Patients who had COVID-19 and developed ICUAW had longer periods of ICU stay, hospital stay, and MV. Bed rest time and use of corticosteroids (for those who required MV) were factors independently associated with ICUAW.

Recovery and long term functional outcome in people with critical illness polyneuropathy and myopathy: a scoping review

BACKGROUND

Intensive care unit acquired weakness (ICUAW), embraces an array of disorders labeled "critical illness polyneuropathy" (CIP), "critical illness myopathy" (CIM) or "critical illness polyneuromyopathy" (CIPNM). Several studies have addressed the various characteristics of ICUAW, but the recovery is still unclear.

OBJECTIVE

The present review investigated the recovery and the long-term functional outcome of subjects with ICUAW, whether the types of ICUAW have different outcomes and whether there is any supporting evidence.

METHODS

Literature search was performed from MEDLINE/PubMed, CINAHL, EMBASE, PeDro, Web of Science and Scopus. Inclusion criteria were: i) sample size including five or more subjects; ii) subjects who suffered from ICUAW and/or CIP, CIM and CIP/CIM; iii) ICUAW ascertained by EMG. Follow-ups longer than one year were defined as long-term.

RESULTS

Twenty-nine studies met the inclusion criteria. In total, 788 subjects with ICUAW were enrolled: 159 (20.1%) died and 588 (74.6%) were followed. Of all the included patients, 613 (77.7%) had CIP, 82 (10.4%) CIM and 56 (7.1%) CIP/CIM. Overall, 70.3% of the subjects with ICUAW fully recovered. Seven (24.1%) studies had a follow-up longer than 1 year (range 2-8) with 173 (21.9%) subjects enrolled globally and 108 followed. Of these subjects, 88.8% gained full recovery. Most of the studies did not use proper functional scales and only 4 and 3 studies employed the Barthel scale and the Functional Independence Measure (FIM) scale. Differentiation between the types of ICUAW was performed in 7 studies, but only 3 studies reported that subjects with CIM had a better prognosis and earlier recovery than subjects with CIP/CIM.

CONCLUSIONS

Subjects with ICUAW could achieve good recovery and could improve at follow-up. However, the quality of the published studies due to short follow-ups and the paucity of defined outcome measures require confirms.

Post-Intensive Care Syndrome in Survivors from Critical Illness including COVID-19 Patients: A Narrative Review

Current achievements in medical science and technological advancements in intensive care medicine have allowed better support of critically ill patients in intensive care units (ICUs) and have increased survival probability. Post-intensive care syndrome (PICS) is a relatively new term introduced almost 10 years ago, defined as "new or worsening impairments in physical, cognitive, or mental health status arising after critical illness and persisting beyond acute care hospitalization". A significant percentage of critically ill patients suffer from PICS for a prolonged period of time, with physical problems being the most common. The exact prevalence of PICS is unknown, and many risk factors have been described well. Coronavirus disease 2019 (COVID-19) survivors seem to be at especially high risk for developing PICS. The families of ICU survivors can also be affected as a response to the stress suffered during the critical illness of their kin. This separate entity is described as PICS family (PICS-F). A multidisciplinary approach is warranted for the treatment of PICS, involving healthcare professionals, clinicians, and scientists from different areas. Improving outcomes is both challenging and imperative for the critical care community. The review of the relevant literature and the study of the physical, cognitive, and mental sequelae could lead to the prevention and timely management of PICS and the subsequent improvement of the quality of life for ICU survivors.

Intensive Care Unit-acquired Neuromuscular Weakness: A Prospective Study on Incidence, Clinical Course, and Outcomes

Background

Neuromuscular weakness may manifest subsequent to critical illness in intensive care unit (ICU) patients. This weakness termed as “ICU-acquired weakness” (ICUAW) has a significant bearing on the length of mechanical ventilation, duration of ICU stays, long-term disability, and survival rate. Early identification of ICUAW helps in planning appropriate strategies, as well as in predicting the prognosis and long-term outcomes of these patients.

Aims and objectives

To identify the incidence of new-onset neuromuscular weakness developing among patients admitted in the ICU (ICUAW) and study its clinical course and impact on the duration of ICU stay.

Methods

This prospective observational study evaluated patients admitted to the ICU over a period of 1 year and 3 months (November 1, 2015, to January 31, 2017). All patients fulfilling the inclusion and exclusion criteria were evaluated with the Medical Research Council (MRC) score for muscle strength. Patients with an average score <4 were diagnosed with ICUAW. Included patients were examined on alternate days to study the clinical progression of the weakness till ICU discharge or death of the patient. The duration of ICU stay was noted.

Results and conclusion

The study revealed a significant association of ICUAW with age, Acute Physiology And Chronic Health Evaluation (APACHE II) Score, duration of mechanical ventilation, and ICU mortality. The incidence of the weakness was found to be 7.83% among the patients who survived and 50% among those patients who did not survive critical illness.

How to cite this article

Baby S, George C, Osahan NM. Intensive Care Unit-acquired Neuromuscular Weakness: A Prospective Study on Incidence, Clinical Course, and Outcomes. Indian J Crit Care Med 2021;25(9):1006–1012.

Aerobic exercise capacity in long-term survivors of critical illness: secondary analysis of the post-EPaNIC follow-up study

Purpose

To evaluate aerobic exercise capacity in 5-year intensive care unit (ICU) survivors and to assess the association between severity of organ failure in ICU and exercise capacity up to 5-year follow-up.

Methods

Secondary analysis of the EPaNIC follow-up cohort (NCT00512122) including 433 patients screened with cardiopulmonary exercise testing (CPET) between 1 and 5 years following ICU admission. Exercise capacity in 5-year ICU survivors (N = 361) was referenced to a historic sedentary population and further compared to demographically matched controls (N = 49). In 5-year ICU survivors performing a maximal CPET (respiratory exchange ratio > 1.05, N = 313), abnormal exercise capacity was defined as peak oxygen consumption (VO₂peak) < 85% of predicted peak oxygen consumption (%predVO₂peak), based on the historic sedentary population. Exercise liming factors were identified. To study the association between severity of organ failure, quantified as the maximal Sequential Organ Failure Assessment score during ICU-stay (SOFA-max), and exercise capacity as assessed with VO₂peak, a linear mixed model was built, adjusting for predefined confounders and including all follow-up CPET studies.

Results

Exercise capacity was abnormal in 118/313 (37.7%) 5-year survivors versus 1/48 (2.1%) controls with a maximal CPET, p < 0.001. Aerobic exercise capacity was lower in 5-year survivors than in controls (VO₂peak: 24.0 ± 9.7 ml/min/kg versus 31.7 ± 8.4 ml/min/kg, p < 0.001; %predVO₂peak: 94% ± 31% versus 123% ± 25%, p < 0.001). Muscular limitation frequently contributed to impaired exercise capacity at 5-year [71/118 (60.2%)]. SOFA-max independently associated with VO₂peak throughout follow-up.

Conclusions

Critical illness survivors often display abnormal aerobic exercise capacity, frequently involving muscular limitation. Severity of organ failure throughout the ICU stay independently associates with these impairments.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-021-06541-9.

High-dose intravenous immunoglobulins as a therapeutic option in critical illness polyneuropathy accompanying SARS-CoV-2 infection: A case-based review of the literature (Review)

The still ongoing COVID-19 pandemic has exposed the medical community to a number of major challenges. A significant number of patients require admission to intensive care unit (ICU) services due to severe respiratory, thrombotic and septic complications and require long-term hospitalization. Neuromuscular weakness is a common complication in critically ill patients who are treated in ICUs and are mechanically ventilated. This complication is frequently caused by critical illness myopathy (CIM) or critical illness polyneuropathy (CIP) and leads to difficulty in weaning from the ventilator. It is thought to represent an important neurologic manifestation of the systemic inflammatory response syndrome (SIRS). COVID-19 infection is known to trigger strong immune dysregulation, with an intense cytokine storm, as a result, the frequency of CIP is expected to be higher in this setting. The mainstay in the diagnosis of this entity beside the high level of clinical awareness is the electrophysiological examination that provides evidence of axonal motor and sensory polyneuropathy. The present article presents the case of a 54-year-old woman with severe COVID 19 infection who developed neuromuscular weakness, which turned out to be secondary to CIP and was treated successfully with a high dose of human intravenous immunoglobulins. Related to this case, we reviewed the relevant literature data regarding the epidemiology, pathophysiology and clinical features of this important complication and discussed also the treatment options and prognosis.

Use of Organ Dysfunction as a Primary Outcome Variable Following Cecal Ligation and Puncture: Recommendations for Future Studies

Outcomes variables for research on sepsis have centered on mortality and changes in the host immune response. However, a recent task force (Sepsis-3) revised the definition of sepsis to "life-threatening organ dysfunction caused by a dysregulated host response to infection." This new definition suggests that human studies should focus on organ dysfunction. The appropriate criteria for organ dysfunction in either human sepsis or animal models are, however, poorly delineated, limiting the potential for translation. Further, in many systems, the difference between "dysfunction" and "injury" may not be clear. In this review, we identify criteria for organ dysfunction and/or injury in human sepsis and in rodents subjected to cecal ligation and puncture (CLP), the most commonly used animal model of sepsis. We further examine instances where overlap between human sepsis and CLP is sufficient to identify translational endpoints. Additional verification may demonstrate that these endpoints are applicable to other animals and to other sepsis models, for example, pneumonia. We believe that the use of these proposed measures of organ dysfunction will facilitate mechanistic studies on the pathobiology of sepsis and enhance our ability to develop animal model platforms to evaluate therapeutic approaches to human sepsis.

Muscle atrophy in critically ill patients : a review of its cause, evaluation, and prevention

Critically ill patients exhibit prominent muscle atrophy, which occurs rapidly after ICU admission and leads to poor clinical outcomes. The extent of atrophy differs among muscles as follows: upper limb: 0.7%-2.4% per day, lower limb: 1.2%-3.0% per day, and diaphragm 1.1%-10.9% per day. This atrophy is caused by numerous risk factors such as inflammation, immobilization, nutrition, hyperglycemia, medication, and mechanical ventilation. Muscle atrophy should be monitored noninvasively by ultrasound at the bedside. Ultrasound can assess muscle mass in most patients, although physical assessment is limited to almost half of all critically ill patients due to impaired consciousness. Important strategies to prevent muscle atrophy are physical therapy and electrical muscular stimulation. Electrical muscular stimulation is especially effective for patients with limited physical therapy. Regarding diaphragm atrophy, mechanical ventilation should be adjusted to maintain spontaneous breathing and titrate inspiratory pressure. However, the sufficient timing and amount of nutritional intervention remain unclear. Further investigation is necessary to prevent muscle atrophy and improve long-term outcomes. J. Med. Invest. 67 : 1-10, February, 2020.

Hyperlactacidemia as a risk factor for intensive care unit-acquired weakness in critically ill adult patients

INTRODUCTION/AIMS

Intensive care unit-acquired weakness (ICUAW) is a severe neuromuscular complication of critical illness. Serum lactate is a useful biomarker in critically ill patients. The relationship between serum lactate level and ICUAW remains controversial. This study evaluated whether hyperlactacidemia (lactate level >2 mmol/L) was an independent risk factor for ICUAW in critically ill adult patients.

METHODS

An observational cohort study was performed in a general multidisciplinary intensive care unit (ICU). Sixty-eight consecutive adult critically ill patients without preexisting neuromuscular disease or a poor pre-ICU functional status whose length of ICU stay was 7 or more days were evaluated. Patients were screened daily for signs of awakening. Muscle strength assessment using the Medical Research Council score was performed on the first day a patient was considered awake. Patients with clinical muscle weakness were considered to have ICUAW.

RESULTS

Among the 68 patients who achieved a satisfactory state of consciousness, the diagnosis of ICUAW was made in 30 patients (44.1%). After multivariate analysis, hyperlactacidemia (P = .02), Acute Physiology and Chronic Health Evaluation II score (P = .04), duration of mechanical ventilation (P = .02), and the use of norepinephrine (P = .04) were found to be significantly associated with the development of ICUAW in critically ill patients.

DISCUSSION

This study shows a number of risk factors to be significantly associated with the development of ICUAW in critically ill adults. These factors should be considered when building early prediction models or designing prevention strategies for ICUAW in future studies.

Pathophysiology and management of critical illness polyneuropathy and myopathy

Critical illness-associated weakness (CIAW) is an umbrella term used to describe a group of neuromuscular disorders caused by severe illness. It can be subdivided into three major classifications based on the component of the neuromuscular system (i.e. peripheral nerves or skeletal muscle or both) that are affected. This includes critical illness polyneuropathy (CIP), critical illness myopathy (CIM), and an overlap syndrome, critical illness polyneuromyopathy (CIPNM). It is a common complication observed in people with critical illness requiring intensive care unit (ICU) admission. Given CIAW is found in individuals experiencing grave illness, it can be challenging to study from a practical standpoint. However, over the past 2 decades, many insights into the pathophysiology of this condition have been made. Results from studies in both humans and animal models have found that a profound systemic inflammatory response and factors related to bioenergetic failure as well as microvascular, metabolic, and electrophysiological alterations underlie the development of CIAW. Current management strategies focus on early mobilization, achieving euglycemia, and nutritional optimization. Other interventions lack sufficient evidence, mainly due to a dearth of large trials. The goal of this Physiology in Medicine article is to highlight important aspects of the pathophysiology of these enigmatic conditions. It is hoped that improved understanding of the mechanisms underlying these disorders will lead to further study and new investigations for novel pharmacologic, nutritional, and exercise-based interventions to optimize patient outcomes.

Neuromuscular involvement in COVID-19 critically ill patients

OBJECTIVE

Coronavirus disease 2019 (COVID-19) has a high incidence of intensive care admittance due to the severe acute respiratory syndrome (SARS). Intensive care unit (ICU)-acquired weakness (ICUAW) is a common complication of ICU patients consisting of symmetric and generalised weakness. The aim of this study was to determine the presence of myopathy, neuropathy or both in ICU patients affected by COVID-19 and whether ICUAW associated with COVID-19 differs from other aetiologies.

METHODS

Twelve SARS CoV-2 positive patients referred with the suspicion of critical illness myopathy (CIM) or polyneuropathy (CIP) were included between March and May 2020. Nerve conduction and concentric needle electromyography were performed in all patients while admitted to the hospital. Muscle biopsies were obtained in three patients.

RESULTS

Four patients presented signs of a sensory-motor axonal polyneuropathy and seven patients showed signs of myopathy. One muscle biopsy showed scattered necrotic and regenerative fibres without inflammatory signs. The other two biopsies showed non-specific myopathic findings.

CONCLUSIONS

We have not found any distinctive features in the studies of the ICU patients affected by SARS-CoV-2 infection.

SIGNIFICANCE

Further studies are needed to determine whether COVID-19-related CIM/CIP has different features from other aetiologies. Neurophysiological studies are essential in the diagnosis of these patients.

Critical illness polyneuromyopathy: Functional impact after severe acquired brain injuries

OBJECTIVES

Critical illness polyneuropathy and myopathy (CIPNM) frequently affects critical patients and can occur after severe acquired brain injuries (sABI) influencing the functional recovery. We aimed to assess how the concomitance between CIPNM and sABI might influence the rehabilitative outcomes in terms of functional autonomy, oral feeding recovery and endotracheal tube weaning.

MATERIALS AND METHODS

Adult patients with sABI admitted to an intensive rehabilitation unit and underwent an electromyography examination within seven days after admission were included. Assessed rehabilitative outcomes at discharge were decannulation success and its timing, functional autonomy measured by the Functional Independence Measure (FIM) and the Glasgow outcome scale expanded (GOS-E) and oral feeding recovery assessed by the Functional Oral Intake Scale (FOIS) score.

RESULTS

Among the 224 included patients (81 (36%) females, age (median[IQR]): 68.73[21.66] years), 119 (53.1%) presented CIPNM at admission. Albeit the change of rehabilitative outcomes between admission and discharge was significant in all the sABI patients (P < .001 for ΔFOIS, ΔFIM and ΔGOS-E), those with a concomitant CIPNM achieved significantly lower scores as evaluated by Mann-Whitney tests (P < .001 for ΔFIM Δ and GOS-E; P < .005 for ΔFOIS). The CIPNM absence was associated with a higher probability to achieve functional autonomy (GOS-E > 4) (OR:4.57 (1.49/14.06); P < .01) and oral feeding recovery (FOIS ≥ 4) (OR:2.07 (1.07/3.99); P = .03) at discharge. CIPNM presence did not influence decannulation success but a longer time to cannula weaning was required (P < .01 in the log-rank test).

CONCLUSIONS

CIPMN significantly affects the rehabilitative outcomes after a sABI and should be taken into account for better rehabilitative handling.

Intensive Care Unit-Acquired Weakness: Not just Another Muscle Atrophying Condition

Intensive care unit-acquired weakness (ICUAW) occurs in critically ill patients stemming from the critical illness itself, and results in sustained disability long after the ICU stay. Weakness can be attributed to muscle wasting, impaired contractility, neuropathy, and major pathways associated with muscle protein degradation such as the ubiquitin proteasome system and dysregulated autophagy. Furthermore, it is characterized by the preferential loss of myosin, a distinct feature of the condition. While many risk factors for ICUAW have been identified, effective interventions to offset these changes remain elusive. In addition, our understanding of the mechanisms underlying the long-term, sustained weakness observed in a subset of patients after discharge is minimal. Herein, we discuss the various proposed pathways involved in the pathophysiology of ICUAW, with a focus on the mechanisms underpinning skeletal muscle wasting and impaired contractility, and the animal models used to study them. Furthermore, we will explore the contributions of inflammation, steroid use, and paralysis to the development of ICUAW and how it pertains to those with the corona virus disease of 2019 (COVID-19). We then elaborate on interventions tested as a means to offset these decrements in muscle function that occur as a result of critical illness, and we propose new strategies to explore the molecular mechanisms of ICUAW, including serum-related biomarkers and 3D human skeletal muscle culture models.

Critical Illness Myopathy

Critical illness myopathy (CIM) is a primary myopathy associated with increased mortality and morbidity, which frequently develops in severely ill patients. Several risk factors have been suggested for the development of critical illness myopathy. However, neither the exact etiology nor the underlying mechanisms are known in detail. Although for definite diagnosis muscle biopsy is needed, electrophysiological tests are crucial for the diagnosis of probable critical illness myopathy and differential diagnosis. In this review, conventional electrophysiological tests such as nerve conduction studies, needle electromyography, direct muscle stimulation, and repetitive stimulation for diagnosis of critical illness myopathy are summarized. Moreover, studies using the novel method of recording muscle velocity recovery cycles are addressed.

Aminoglycoside use and intensive care unit-acquired weakness: A systematic review and meta-analysis

Background

The relationship between aminoglycoside use and intensive care unit (ICU)-acquired weakness remains controversial. In the present study, we performed a systematic review and meta-analysis to examine the relationship between aminoglycoside use and ICU-acquired weakness in critically ill patients.

Methods

The PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials and Cumulative Index of Nursing and Allied Health Literature databases were searched from the earliest available date to July 10, 2019. Randomized controlled trials and prospective cohort studies examining the relationship between aminoglycosides and ICU-acquired weakness in adult ICU patients were included. Two authors independently screened titles/abstracts, reviewed full text and extracted data from the included studies. We performed the Meta-analysis using Stata version 15.0 and used the DerSimonian-Laird random effects model for data analyses. Heterogeneity was evaluated using the χ² statistic and I² statistic. Publication bias was evaluated with funnel plots qualitatively, the Begg’s test and Egger’s test quantitatively.

Results

Ten prospective cohort studies were included and analysed in this review. The overall effect sizes of the studies revealed a statistically significant relationship between aminoglycoside use and ICU-acquired weakness (OR, 2.06; 95%CI, 1.33–3.21; I² = 56%). Subgroup and sensitivity analyses suggested a significant association between aminoglycoside use and studies limited to patients with clinical weakness (OR, 2.74; 95%CI, 1.83–4.10; I² = 0%), and not to studies limited to patients with abnormal electrophysiology (OR, 1.78; 95%CI, 0.94–3.39; I² = 59%), a large sample size (OR, 1.81; 95%CI, 0.97–3.39; I² = 75%), or low risk of bias (OR, 1.59; 95%CI, 0.97–2.60; I² = 56%); however, statistical heterogeneity was obvious. There were no significant publication biases found in the review.

Conclusions

The review revealed a significant relationship between aminoglycoside use and ICU-acquired weakness.

Impact of Very Early Physical Therapy During Septic Shock on Skeletal Muscle: A Randomized Controlled Trial

Supplemental Digital Content is available in the text.

Objectives:

As the catabolic state induced by septic shock together with the physical inactivity of patients lead to the rapid loss of muscle mass and impaired function, the purpose of this study was to test whether an early physical therapy during the onset of septic shock regulates catabolic signals and preserves skeletal muscle mass.

Design:

Randomized controlled trial.

Setting:

Tertiary mixed ICU.

Patients:

Adult patients admitted for septic shock within the first 72 hours.

Interventions:

Patients were assigned randomly into two groups. The control group benefited from manual mobilization once a day. The intervention group had twice daily sessions of both manual mobilization and 30-minute passive/active cycling therapy.

Measurements and Main Results:

Skeletal muscle biopsies and electrophysiology testing were performed at day 1 and day 7. Muscle biopsies were analyzed for histology and molecular components of signaling pathways regulating protein synthesis and degradation as well as inflammation markers. Hemodynamic values and patient perception were collected during each session. Twenty-one patients were included. Three died before the second muscle biopsy. Ten patients in the control and eight in the intervention group were analyzed. Markers of the catabolic ubiquitin-proteasome pathway, muscle atrophy F-box and muscle ring finger-1 messenger RNA, were reduced at day 7 only in the intervention group, but without difference between groups (muscle atrophy F-box: –7.3% ± 138.4% in control vs –56.4% ± 37.4% in intervention group; p = 0.23 and muscle ring finger-1: –30.8% ± 66.9% in control vs –62.7% ± 45.5% in intervention group; p = 0.15). Muscle fiber cross-sectional area (µm²) was preserved by exercise (–25.8% ± 21.6% in control vs 12.4% ± 22.5% in intervention group; p = 0.005). Molecular regulations suggest that the excessive activation of autophagy due to septic shock was lower in the intervention group, without being suppressed. Markers of anabolism and inflammation were not modified by the intervention, which was well tolerated by the patients.

Conclusions:

Early physical therapy during the first week of septic shock is safe and preserves muscle fiber cross-sectional area.

Use of handgrip dynamometry for diagnosis and prognosis assessment of intensive care unit acquired weakness: A prospective study

OBJECTIVES

To test the agreement between handgrip dynamometry and Medical Research Council (MRC) criteria for the diagnosis of intensive care unit acquired weakness (ICUAW) and to evaluate if dynamometry findings are associated with morbidity and mortality.

METHODS

A prospective single center cohort study was conducted in a Brazilian ICU. Adults requiring at least 5 days of critical care were included. Primary outcome was the agreement between ICUAW diagnosis as assessed by the MRC score and the handgrip strength dynamometry. Exploratory outcomes were in-ICU, in-hospital, 6-month and one-year mortality, days of mechanical ventilation, length of ICU and hospital stay (in the present hospitalization and during the 6-month follow-up) and ICU readmission in six months.

RESULTS

We included 45 consecutive subjects, of which 18 of them had ICUAW according to MRC criteria. Using sex specific thresholds, handgrip strength had high agreement with MRC criteria for ICUAW diagnosis (100% accuracy; Kappa coefficient = 1; p<0,001). ICUAW was associated with more days of mechanical ventilation, longer length of ICU stay and hospital stay in six months. There were no differences regarding mortality.

CONCLUSIONS

Handgrip dynamometry may provide a simple and accurate alternative to the MRC examination for the diagnosis of ICUAW. ICUAW is associated with longer ICU and hospital stay and more requirement of mechanical ventilation.

Clinical review: peripheral muscular ultrasound in the ICU

Muscular weakness developing from critical illness neuropathy, myopathy and muscle atrophy has been characterized as intensive care unit-acquired weakness (ICUAW). This entity occurs commonly during and after critical care stay. Various causal factors for functional incapacity have been proposed. Among these, individual patient characteristics (such as age, comorbidities and nutritional status), acting in association with sustained bed rest and pharmacological interventions (included the metabolic support approach), seem influential in reducing muscular mass. Long-term outcomes in heterogeneous ICUAW populations include transient disability in 30% of patients and persistent disabilities that may occur even in patients with nearly complete functional recovery. Currently available tools for the assessment of skeletal muscle mass are imprecise and difficult to perform in the ICU setting. A valid alternative to these imaging modalities is muscular ultrasonography, which allows visualization and classification of muscle characteristics by cross-sectional area, muscle layer thickness, echointensity by grayscale and the pennation angle). The aim of this narrative review is to describe the current literature addressing muscular ultrasound for the detection of muscle weakness and its potential impact on treatment and prognosis of critically ill patients when combined with biomarkers of muscle catabolism/anabolism and bioenergetic state. In addition, we suggest a practical flowchart for establishing an early diagnosis.

Vamorolone treatment improves skeletal muscle outcome in a critical illness myopathy rat model

AIM

Critical illness myopathy (CIM) is a consequence of modern critical care, leading to skeletal muscle atrophy/paralysis with negative consequences for mortality/morbidity and health care costs. Glucocorticoids (GCs) have been proposed to trigger CIM. Here, we compare outcomes of two GCs, the commonly used prednisolone and the newly developed dissociative vamorolone in response to the intensive care unit (ICU) condition for 5 days, ie, sedation, immobilization, and mechanical ventilation.

METHODS

Rats were divided into a 0-day sham-operated control group, and three groups exposed to 5 days ICU condition during treatment with prednisolone (PRED) or vamorolone (VAM) or none of these GCs (ICU-group). Survival, body and muscle weights, cytokine concentrations, regulation of muscle contraction in single fast- and slow-twitch muscle fibres, myofibrillar protein expression and protein degradation pathways were studied.

RESULTS

Critical illness myopathy geno- and pheno-types were confirmed in the ICU group. However, VAM and PRED groups showed reduced atrophy/weakness than the ICU group, and muscle specific differences with more severe negative effects on fast-twitch muscle fibres in the PRED than the other groups.

CONCLUSION

These results show that vamorolone provides a GC intervention superior to typical GCs in improving CIM outcomes. Further, the findings do not support the notion that moderate-dose GC treatment represents a factor triggering CIM.

Early mobilization for mechanically ventilated patients in the intensive care unit: a systematic review and meta-analysis

Background

Early mobilization (EM) is a regimen that was carried out by physiotherapists in a relatively early stage. It has been investigated by an increasing number of researchers. However, there has not been a meta-analysis concerning whether EM could benefit the clinical outcomes of critically ill patients requiring mechanical ventilation (MV). The present systematic review aims to evaluate the effect of EM compared with immobilization for mechanically ventilated patients.

Methods

A computerized literature search was performed in six databases for related articles from inception to June 2017. We included randomized controlled trials and controlled clinical trials and used the Physiotherapy Evidence Database scale to assess the quality of included studies. Primary outcomes were measures of muscle function, duration of MV, and incidence of mortality. Secondary outcomes were adverse effects and length of stay (LOS) in intensive care unit (ICU) and hospital.

Results

Eight trials were included; of those, only one study without standard EM reported that the intervention was invalid to improve the outcomes. The result of meta-analysis indicated that EM shortened the duration of MV; however, it had no positive effect on mortality and LOS in ICU.

Conclusions

This review suggests that EM improves the muscle function and ventilation duration. Further research highlighting standard intervention and specific groups is needed.

Neuromuscular electrical stimulation combined with exercise decreases duration of mechanical ventilation in ICU patients: A randomized controlled trial

BACKGROUND

Early mobilization can be employed to minimize the duration of intensive care. However, a protocol combining neuromuscular electrical stimulation (NMES) with early mobilization has not yet been tested in ICU patients. Our aim was to assess the efficacy of NMES, exercise (EX), and combined therapy (NMES + EX) on duration of mechanical ventilation (MV) in critically ill patients.

METHODS

The participants in this randomized double-blind trial were prospectively recruited within 24 hours following admission to the intensive care unit of a tertiary hospital. Eligible patients had 18 years of age or older; MV for less than 72 hours; and no known neuromuscular disease. Computer-generated permuted block randomization was used to assign patients to NMES, EX, NMES + EX, or standard care (control group). The main endpoint was duration of MV. Clinical characteristics were also evaluated and intention to treat analysis was employed.

RESULTS

One hundred forty-four patients were assessed for eligibility to participate in the trial, 51 of whom were enrolled and randomly allocated into four groups: 11 patients in the NMES group, 13 in the EX group, 12 in the NMES + EX group, and 15 in the control group (CG). Duration of MV (days) was significantly shorter in the combined therapy (5.7 ± 1.1) and NMEN (9.0 ± 7.0) groups in comparison to CG (14.8 ± 5.4).

CONCLUSIONS

NMES + EX consisting of NMES and active EXs was well tolerated and resulted in shorter duration of MV in comparison to standard care or isolated therapy (NMES or EX alone).

Quantitative peripheral muscle ultrasound in sepsis: Muscle area superior to thickness

PURPOSE

The objective of this study is to describe the relationship between two quantitative muscle ultrasound measures, the rectus femoris cross-sectional area (RF-CSA) and quadriceps muscle thickness, with volitional measures of strength and function in critically ill patients with sepsis.

MATERIALS AND METHODS

We performed a prospective study of patients admitted to a medical ICU with sepsis and shock or respiratory failure. We examined the association of two ultrasound measurements - the RF-CSA and quadriceps muscle thickness - with strength and function at day 7. Strength was determined using the Medical Research Council Score and function using Physical Function in the ICU Test, scored.

RESULTS

Twenty-nine patients were enrolled; 19 patients had outcome testing performed. Over 7days, RF-CSA and thickness decreased by an average of 23.2% and 17.9%, respectively. The rate of change per day of RF-CSA displayed a moderate correlation with strength (ρ 0.51, p-value 0.03) on day 7. Baseline and day 7 RF-CSA did not show a significant correlation with either outcome. Quadriceps muscle thickness did not significantly correlate with either outcome.

CONCLUSIONS

Muscle atrophy as detected by the rate of change in RF-CSA moderately correlated with strength one week after sepsis admission.

Corticosteroid use and intensive care unit-acquired weakness: a systematic review and meta-analysis

Background

The association between corticosteroid use and intensive care unit (ICU)-acquired weakness remains unclear. We evaluated the relationship between corticosteroid use and ICU-acquired weakness in critically ill adult patients.

Methods

The PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials, and Cumulative Index of Nursing and Allied Health Literature databases were searched from database inception until October 10, 2017. Two authors independently screened the titles/abstracts and reviewed full-text articles. Randomized controlled trials and prospective cohort studies evaluating the association between corticosteroids and ICU-acquired weakness in adult ICU patients were selected. Data extraction from the included studies was accomplished by two independent reviewers. Meta-analysis was performed using Stata version 12.0. The results were analyzed using odds ratios (ORs) and 95% confidence intervals (CIs). Data were pooled using a random effects model, and heterogeneity was evaluated using the χ² and I² statistics. Publication bias was qualitatively analyzed with funnel plots, and quantitatively analyzed with Begg’s test and Egger’s test.

Results

One randomized controlled trial and 17 prospective cohort studies were included in this review. After a meta-analysis, the effect sizes of the included studies indicated a statistically significant association between corticosteroid use and ICU-acquired weakness (OR 1.84; 95% CI 1.26–2.67; I² = 67.2%). Subgroup analyses suggested a significant association between corticosteroid use and studies limited to patients with clinical weakness (OR 2.06; 95% CI 1.27–3.33; I² = 60.6%), patients with mechanical ventilation (OR 2.00; 95% CI 1.23–3.27; I² = 66.0%), and a large sample size (OR 1.61; 95% CI 1.02–2.53; I² = 74.9%), and not studies limited to patients with abnormal electrophysiology (OR 1.65; 95% CI 0.92–2.95; I² = 70.6%) or patients with sepsis (OR 1.96; 95% CI 0.61–6.30; I² = 80.8%); however, statistical heterogeneity was obvious. No significant publication biases were found in the review. The overall quality of the evidence was high for the randomized controlled trial and very low for the included prospective cohort studies.

Conclusions

The review suggested a significant association between corticosteroid use and ICU-acquired weakness. Thus, exposure to corticosteroids should be limited, or the administration time should be shortened in clinical practice to reduce the risk of ICU-acquired weakness.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-2111-0) contains supplementary material, which is available to authorized users.

Risk factors for intensive care unit-acquired weakness: A systematic review and meta-analysis

Intensive care unit-acquired weakness (ICUAW) occurs frequently in the context of critical illness without alternative plausible cause and specific treatment options, and it is important to identify and summarize the independent risk factors for ICUAW. PubMed, Embase, Central, China Biological Medicine, China National Knowledge Infrastructure, VIP and Wanfang databases were searched from database inception until 10 July 2017. Prospective cohort studies on adult ICU patients who were diagnosed with ICUAW using either clinical or electrophysiological criteria were selected. Meta-analysis was performed using Stata version 12.0. The results were analysed using odds ratios (OR) and 95% confidence intervals (CI). Data were pooled using a random-effects model, and heterogeneity was assessed using the I² statistic. Qualitative analysis and systematic review were used for risk factors that were deemed inappropriate to combine. Fourteen prospective cohort studies were included in this review. The meta-analysis showed that Acute Physiology and Chronic Health Evaluation II score (OR, 1.05; 95%CI, 1.01-1.10), neuromuscular blocking agents (OR, 2.03; 95%CI, 1.22-3.40) and aminoglycosides (OR, 2.27; 95%CI, 1.07-4.81) were found to be significantly associated with ICUAW. Other risk factors, including female, multiple organ failure, systemic inflammatory response syndrome, sepsis, electrolyte disturbances, hyperglycaemia, hyperosmolarity, high lactate level, duration of mechanical ventilation, parenteral nutrition and use of norepinephrine, were statistically significant on multivariable analysis in each single studies. This review provides a number of independent risk factors for ICUAW, which should be guided for early prediction and prevention of the disorder.

Intensive Care Unit-Acquired Weakness

Intensive care unit-acquired weakness (ICUAW) is a substantial contributor to long-term disability in survivors of critical illness. Critical illness polyneuropathy, critical illness myopathy, and muscle atrophy from disuse contribute in various proportions to ICUAW. ICUAW is a clinical diagnosis supported by electrophysiology and newer diagnostic tests, such as muscle ultrasound. Risk factor reduction, including the aggressive treatment of sepsis and early mobilization, improves outcome. Although some patients with ICUAW experience a full recovery, for others improvement is slow and incomplete and quality of life is adversely affected. This article examines aspects of ICUAW and identifies potential areas of further study.

Impact of limb weakness on extubation failure after planned extubation in medical patients

BACKGROUND AND OBJECTIVE

Limb muscle weakness is associated with difficult weaning. However, there are limited data on extubation failure. The objective of this cohort study was to evaluate the association between limb muscle weakness according to the Medical Research Council (MRC) scale and extubation failure rates among patients in a medical intensive care unit (ICU).

METHODS

All consecutive medical ICU patients who were mechanically ventilated for more than 24 h and who were weaned according to protocol were prospectively registered, and limb muscle weakness was assessed using the MRC scale on the day of planned extubation. Association of limb muscle weakness with extubation failure within 48 h following planned extubation was evaluated with logistic regression analysis.

RESULTS

Over the study period, 377 consecutive patients underwent planned extubation through a standardized weaning process. Extubation failure occurred in 106 (28.1%) patients. Median scores on the MRC scale for four limbs were lower in patients with extubation failure (14, interquartile range (IQR) 12-16) than in patients without extubation failure (16, IQR 12-18; P = 0.024). In addition, extubation failure rates decreased significantly with increasing quartiles of MRC scores (P for trend <0.001). In multivariable analysis, MRC scores ≤10 points were independently associated with extubation failure within 48 h (adjusted OR 2.131, 95% CI: 1.071-4.240, P = 0.031).

CONCLUSION

Limb muscle weakness assessed on the day of extubation was found to be independently associated with higher extubation failure rates within 48 h following planned extubation in medical patients.

Efficacy of early passive tilting in minimizing ICU-acquired weakness: A randomized controlled trial

Purpose

To investigate whether passive tilting added to a standardized rehabilitation therapy improved strength at Intensive Care Unit (ICU) discharge.

Material and methods

This single-center trial included patients admitted to an adult surgical ICU and ventilated for at least 3 days. Patients were randomized to daily standardized rehabilitation therapy alone or with tilting on a table for at least 1 h. The primary outcome was the Medical Research Council (MRC) sum score at ICU discharge. Muscular recovery was a secondary outcome.

Results

Of 145 included patients, 125 received mobilization, 65 in the Tilt group and 60 in the Control group. Total mobilization duration (median [25th–75th percentiles]) in the Tilt group was 1020 [580–1695] versus 1340 [536–2775] minutes in the Control group (p = 0.313). MRC sum scores at ICU discharge were not significantly different between groups (Tilt, 50 [45–56] versus 48 [45–54]; p = 0.555). However, the number of patients with weakness was higher in the Tilt group at baseline (Tilt: 60/65 versus 48/60, p = 0.045) and muscular recovery was better in the Tilt group (p = 0.004).

Conclusions

Passive tilting added to a standardized rehabilitation therapy did not improve muscle strength at ICU discharge in surgical patients even if a faster recovery with tilting is suggested.