Pharmacological Therapy for the Prevention and Treatment of Weakness After Critical Illness: A Systematic Review

Weakness acquired in the cardiac intensive care unit: still the elephant in the room?

Over the past two decades, the cardiac critical care population has shifted to increasingly comorbid and elderly patients often presenting with nonprimary cardiac conditions that exacerbate underlying advanced cardiac disease. Consequently, the modern cardiac intensive care unit (CICU) patient has poor outcome regardless of left ventricular ejection fraction. Importantly, delayed liberation from organ support, independent from premorbid health status and admission severity of illness, has been associated with increased morbidity and mortality up to years post-general critical care. Although a constellation of several acquired morbidities is at play, the most prominent enactor of poor long-term outcome in this population appears to be intensive care unit acquired weakness. Although the specific burden of ICU-acquired morbidities in CICU patients is yet to be clearly defined, it seems unfathomable that patients will not accrue some sort of ICU-related morbidity. There is hence an urgent need to better establish the exact benefit and cost of resource-intensive strategies in both short- and long-term survival of the CICU patient. Consequent and standardized documentation of admission comorbidities, severity of illness indicators, relevant ICU-related complications including weakness, and long-term post-ICU morbidity outcomes can help our understanding of the disease continuum and how to better care for the CICU survivor and their families and caregivers. Given increasing budgetary pressure on healthcare systems worldwide, interventions targeting CICU patients should focus on improving patient-centred long-term outcomes in a cost-effective manner. It will require a holistic and transmural continuity of care model to meet the challenges associated with treating critically ill cardiac patients in the future.

Muscle Dysfunction and Physical Recovery After Critical Illness

During critical illness, patients experience significant and rapid onsets of muscle wasting and dysfunction with loss of strength, mass, and power. These deficits often persist long after the ICU, leading to impairments in physical function including reduced exercise capacity and increased frailty and disability. While there are numerous studies describing the epidemiology of impaired muscle and physical function in the ICU, there are significantly fewer data investigating mechanisms of prolonged and persistent impairments in ICU survivors. Additionally, while several potential clinical risk factors associated with poor physical recovery have been identified, there remains a dearth of interventions that have effectively improved outcomes long-term among survivors. In this article, we aim to provide a thorough, evidence-based review of the current state of knowledge regarding muscle dysfunction and physical function after critical illness with a focus on post-ICU and post-hospitalization phase of recovery.

Growth differentiation factor-15 as a biomarker for intensive care unit-acquired weakness: a meta-analysis

Background

Growth differentiation factor-15 (GDF-15) may be a potential biomarker for intensive care unit-acquired weakness (ICU-AW). In this study, we aimed to quantitative analysis the levels of GDF-15 in patients with ICU-AW and in non-ICU-AW, and then to determine its potential diagnostic utility.

Methods

Two researchers separately conducted a systematic search of the relevant studies up to May 2023 in various literature databases (PubMed, Cochrane, Web of Science, Embase, and CINAHL). Studies were selected according to the inclusion and exclusion criteria, and quality evaluation of the included studies was conducted by using QUADAS-2 provided by Review Manager 5.3. The software packages Meta Disc (C1.4) and Stata17.0 were used for the meta-analysis. The data were combined with fixed-effects model, and the summary receiver operating characteristic curve was drawn to evaluate the overall diagnostic accuracy of GDF-15.

Results

We identified 6 eligible studies comprising 401 patients with ICU-AW. The sensitivity, specificity, diagnostic odds ratio (DOR), and area under the curve (AUC) for the discriminative performance of GDF-15 as a diagnostic biomarker were 0.82 (95% confidence interval (CI):0.78-0.86), 0.83 (95% CI: 0.61-0.88), 21.39 (95% CI: 13.36-34.24), and 0.88 (95% CI: 0.85-0.91), respectively.

Conclusion

GDF-15 is a candidate biomarker in diagnosing of ICU-AW from non-ICU-AW.

Early urea-to-creatinine ratio to predict rapid muscle loss in critically ill patients with sepsis: a single-center retrospective observational study

BACKGROUND

Patients with sepsis in the intensive care unit (ICU) often experience rapid muscle loss. The urea-to-creatinine ratio (UCR) is thought to reflect muscle breakdown (creatinine) and catabolism (urea) and is commonly used to assess nutritional and metabolic status. This study aimed to investigate whether changes in UCR (ΔUCR) can predict the development of rapid muscle loss in patients with sepsis.

METHODS

This retrospective observational study was conducted in a university ICU between 2014 and 2021, involving adult patients (≥ 18 years) diagnosed with sepsis. The primary outcome was the incidence of rapid muscle loss during ICU hospitalization. Changes in the cross-sectional muscle area at the third lumbar vertebra (L3SMA) were measured using CT images to evaluate muscle loss. Rapid muscle loss was defined as a change in ΔL3SMA greater than 2% per day. Multivariable logistic regression was used to examine the association between UCR or ΔUCR and rapid muscle loss. The area under the receiver operating characteristic curve (AUC) was calculated to assess the predictive performance of UCR or ΔUCR for rapid muscle loss.

RESULTS

Of the 482 patients, 141 (29.2%) experienced rapid muscle loss during their ICU stay. Multivariable logistic regression analysis revealed that ΔUCR was significantly associated with an increased risk of rapid muscle loss, with an odds ratio (OR) of 1.02 [95% CI: 1.01, 1.02]. The AUC for ΔUCR in predicting rapid muscle loss was 0.76 [95% CI: 0.68-0.83], with a threshold value of 19.4 µmol urea/µmol creatinine for ΔUCR.

CONCLUSION

The results demonstrate that ΔUCR is independently associated with rapid muscle loss in patients with sepsis and the AUC of the ROC curve for the ability of ΔUCR to predict rapid muscle loss was 0.76. Though additional prospective data are needed, our results suggest that ΔUCR may be useful in the early identification of critically ill patients with sepsis at risk of rapid muscle loss.

Roles of programmed death-1 and muscle innate lymphoid cell-derived interleukin 13 in sepsis-induced intensive care unit-acquired weakness

BACKGROUND

Intensive care unit-acquired weakness (ICU-AW) is a syndrome characterized by a long-term muscle weakness often observed in sepsis-surviving patients during the chronic phase. Although ICU-AW is independently associated with increased mortality, effective therapies have yet to be established. Programmed death-1 (PD-1) inhibitors have attracted attention as potential treatments for reversing immune exhaustion in sepsis; however, its impact on ICU-AW remains to be elucidated. Here, we study how PD-1 deficiency affects sepsis-induced skeletal muscle dysfunction in a preclinical sepsis model.

METHODS

Chronic sepsis model was developed by treating wild-type (WT) and PD-1 knockout (KO) mice with caecal slurry, followed by resuscitation with antibiotics and saline. Mice were euthanized on days 15-17. Body weights, muscle weights, and limb muscle strengths were measured. Interleukin 13 (IL-13) and PD-1 expressions were examined by flow cytometry. Messenger RNA (mRNA) expressions of slow-twitch muscles were measured by reverse transcription and quantitative polymerase chain reaction (RT-qPCR). In an in vitro study, C2C12 myotubes were treated with lipopolysaccharide (LPS) and recombinant IL-13 followed by gene expression measurements.

RESULTS

WT septic mice exhibited decreased muscle weight (quadriceps, P < 0.01; gastrocnemius, P < 0.05; and tibialis anterior, P < 0.01) and long-term muscle weakness (P < 0.0001), whereas PD-1 KO septic mice did not exhibit any reduction in muscle weights and strengths. Slow-twitch specific mRNAs, including myoglobin (Mb), troponin I type 1 (Tnni1), and myosin heavy chain 7 (Myh7) were decreased in WT skeletal muscle (Mb, P < 0.0001; Tnni1, P < 0.05; and Myh7, P < 0.05) after sepsis induction, but mRNA expressions of Tnni1 and Myh7 were increased in PD-1 KO septic mice (Mb, not significant; Tnni1, P < 0.0001; and Myh7, P < 0.05). Treatment of C2C12 myotube cells with LPS decreased the expression of slow-twitch mRNAs, which was restored by IL-13 (Mb, P < 0.0001; Tnni1, P < 0.001; and Myh7, P < 0.05). IL-13 production was significantly higher in ILC2s compared to T cells in skeletal muscle (P < 0.05). IL-13-producing ILC2s in skeletal muscle were examined and found to increase in PD-1 KO septic mice, compared with WT septic mice (P < 0.05). ILC2-derived IL-13 was increased by PD-1 KO septic mice and thought to protect the muscles from experimental ICU-AW.

CONCLUSIONS

Long-term muscle weakness in experimental ICU-AW was ameliorated in PD-1 KO mice. ILC2-derived IL-13 production in skeletal muscles was increased in PD-1 KO mice, thereby suggesting that IL-13 alleviates muscle weakness during sepsis. This study demonstrates the effects of PD-1 blockade in preserving muscle strength during sepsis through an increase in ILC2-derived IL-13 and may be an attractive therapeutic target for sepsis-induced ICU-AW.

From the Intensive Care Unit to Recovery: Managing Post-intensive Care Syndrome in Critically Ill Patients

Post-intensive care syndrome (PICS) is the term used to describe the decline in the physical, cognitive, and/or mental condition of individuals who have been discharged from the intensive care unit (ICU). This complication could result in a significant reduction in quality of life, with some patients experiencing symptoms of prolonged weakness, depression, anxiety, and post-traumatic stress disorder (PTSD). Intensive care advancement over the years has resulted in an increase in ICU survival rates and a proportional increase in PICS, creating a need for more in-depth research into the prevention and management of the disease. Hence, this study aims to examine the present body of literature on PICS, encompassing its underlying physiological processes and elements that contribute to its development, methods for evaluating and diagnosing the condition, current treatment choices as well as potential new approaches, and the constraints in managing PICS and the necessity for further investigation. In this article, studies were compiled from several databases, including, but not limited to, Google Scholar, PubMed, and Cochrane Library. These studies were reviewed, and their data were used to highlight important aspects regarding the efficacy of current PICS screening tools, the optimization and limitations of both pharmacologic and non-pharmacologic treatment methods, and the feasibility and safety of emerging treatments and technologies. The major conclusions of this review were centered around the need for multidisciplinary management of PICS. From pharmacological management using analgesia to non-pharmacological management using early mobilization and exercise therapy, the effective treatment of PICS requires a multifaceted approach. Patient follow-up and its importance were touched upon, including strategies and policies to bolster proper follow-up, thereby increasing favorable outcomes. Lastly, the importance of family involvement and the increased need for research into this topic were highlighted.

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.

Early detection and assessment of intensive care unit-acquired weakness: a comprehensive review

Intensive care unit-acquired weakness (ICU-AW) is a serious complication in critically ill patients. Therefore, timely and accurate diagnosis and monitoring of ICU-AW are crucial for effectively preventing its associated morbidity and mortality. This article provides a comprehensive review of ICU-AW, focusing on the different methods used for its diagnosis and monitoring. Additionally, it highlights the role of bedside ultrasound in muscle assessment and early detection of ICU-AW. Furthermore, the article explores potential strategies for preventing ICU-AW. Healthcare providers who manage critically ill patients utilize diagnostic approaches such as physical exams, imaging, and assessment tools to identify ICU-AW. However, each method has its own limitations. The diagnosis of ICU-AW needs improvement due to the lack of a consensus on the appropriate approach for its detection. Nevertheless, bedside ultrasound has proven to be the most reliable and cost-effective tool for muscle assessment in the ICU. Combining the Sequential Organ Failure Assessment (SOFA) score, Acute Physiology and Chronic Health Evaluation (APACHE) II score assessment, and ultrasound can be a convenient approach for the early detection of ICU-AW. This approach can facilitate timely intervention and prevent catastrophic consequences. However, further studies are needed to strengthen the evidence.

Intensive care unit-acquired weakness: From molecular mechanisms to its impact in COVID-2019

Intensive Care Unit-Acquired Weakness (ICU-AW) is a generalized and symmetric neuromuscular dysfunction associated with critical illness and its treatments. Its incidence is approximately 80% in intensive care unit patients, and it manifests as critical illness polyneuropathy, critical illness myopathy, and muscle atrophy. Intensive care unit patients can lose an elevated percentage of their muscle mass in the first days after admission, producing short- and long-term sequelae that affect patients’ quality of life, physical health, and mental health. In 2019, the world was faced with coronavirus disease 2019 (COVID-19), caused by the acute respiratory syndrome coronavirus 2. COVID-19 produces severe respiratory disorders, such as acute respiratory distress syndrome, which increases the risk of developing ICU-AW. COVID-19 patients treated in intensive care units have shown early diffuse and symmetrical muscle weakness, polyneuropathy, and myalgia, coinciding with the clinical presentation of ICU-AW. Besides, these patients require prolonged intensive care unit stays, invasive mechanical ventilation, and intensive care unit pharmacological therapy, which are risk factors for ICU-AW. Thus, the purposes of this review are to discuss the features of ICU-AW and its effects on skeletal muscle. Further, we will describe the mechanisms involved in the probable development of ICU-AW in severe COVID-19 patients.

Chronic critical illness and post-intensive care syndrome: from pathophysiology to clinical challenges

Background

Post‐intensive care syndrome (PICS) encompasses physical, cognition, and mental impairments persisting after intensive care unit (ICU) discharge. Ultimately it significantly impacts the long‐term prognosis, both in functional outcomes and survival. Thus, survivors often develop permanent disabilities, consume a lot of healthcare resources, and may experience prolonged suffering. This review aims to present the multiple facets of the PICS, decipher its underlying mechanisms, and highlight future research directions.

Main text

This review abridges the translational data underlying the multiple facets of chronic critical illness (CCI) and PICS. We focus first on ICU-acquired weakness, a syndrome characterized by impaired contractility, muscle wasting, and persisting muscle atrophy during the recovery phase, which involves anabolic resistance, impaired capacity of regeneration, mitochondrial dysfunction, and abnormalities in calcium homeostasis. Second, we discuss the clinical relevance of post-ICU cognitive impairment and neuropsychological disability, its association with delirium during the ICU stay, and the putative role of low-grade long-lasting inflammation. Third, we describe the profound and persistent qualitative and quantitative alteration of the innate and adaptive response. Fourth, we discuss the biological mechanisms of the progression from acute to chronic kidney injury, opening the field for renoprotective strategies. Fifth, we report long-lasting pulmonary consequences of ARDS and prolonged mechanical ventilation. Finally, we discuss several specificities in children, including the influence of the child’s pre-ICU condition, development, and maturation.

Conclusions

Recent understandings of the biological substratum of the PICS’ distinct features highlight the need to rethink our patient trajectories in the long term. A better knowledge of this syndrome and precipitating factors is necessary to develop protocols and strategies to alleviate the CCI and PICS and ultimately improve patient recovery.

Perceived utility of electrodiagnostic testing in critical illness myopathy and polyneuropathy: A survey of intensive care unit providers

INTRODUCTION/AIMS

Critical illness myopathy (CIM) and critical illness polyneuropathy (CIP) are common disorders associated with substantial morbidity. Electrodiagnostic studies (EDx) are effective in diagnosing CIM/CIP and identifying mimicking conditions. We surveyed intensive care unit (ICU) providers to better understand their approach to ICU-acquired weakness (ICU-AW) and the perceived utility of EDx.

METHODS

This was a single health system, Web-based survey of ICU providers.

RESULTS

Survey responses were received from 52 providers with a response rate of 22.1%. Most providers were somewhat familiar with CIM/CIP and median perceived prevalence was 30-49%. The majority (92.3%) of providers had no standard evaluation approach for ICU-AW. Electrodiagnostic testing was commonly considered, but many providers obtained it infrequently in presumed CIM/CIP cases. Electrodiagnostic studies were used to rule out other causes of weakness or to confirm the diagnosis of CIM/CIP. Many providers ordered EDx within 1 wk of identifying weakness. Finally, EDx were overshadowed by personal experience as the most helpful management tool for ICU-AW.

DISCUSSION

Overall, ICU providers perceive that CIM/CIP are commonly encountered, but they may not have a standard approach to evaluation. Clinical experience increased familiarity of ICU-AW and is central to management. EDx results are usually thought to be helpful, albeit not often ordered, and more study is needed to determine when implementation is of most assistance. Increasing education and developing institutional standards may lead to increased awareness and improved evaluation of CIM/CIP, but more study is needed to determine if algorithmic approaches would change patient outcomes.

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.

Intensive care unit-acquired weakness: Questions the clinician should ask

Intensive care unit (ICU)-acquired weakness (ICU-AW) is defined as clinically detected weakness in critically ill patients in whom there is no plausible etiology other than critical illness. Using electrophysiological methods, patients with ICU-AW are classified in three subcategories: critical illness polyneuropathy, critical illness myopathy and critical illness neuromyopathy. ICU-AW is a frequent complication occurring in critical ill patients. Risk factors include illness severity and organ failure, age, hyperglycemia, parenteral nutrition, drugs and immobility. Due to short- and long-term complications, ICU-AW results in longer hospital stay and increased mortality. Its management is essentially preventive avoiding modifiable risk factors, especially duration of sedation and immobilization that should be as short as possible. Pharmacological approaches have been studied but none have proven efficacy. In the present review, we propose practical questions that the clinician should ask in case of acquired weakness during ICU stay: when to suspect ICU-AW, what risk factors should be identified, how to diagnose ICU-AW, what is the prognosis and how can recovery be improved?

Association of Diabetes Mellitus and Alcohol Abuse with Cancer: Molecular Mechanisms and Clinical Significance

Diabetes mellitus (DM), one of the metabolic diseases which is characterized by sustained hyperglycemia, is a life-threatening disease. The global prevalence of DM is on the rise, mainly in low- and middle-income countries. Diabetes is a major cause of blindness, heart attacks, kidney failure, stroke, and lower limb amputation. Type 2 diabetes mellitus (T2DM) is a form of diabetes that is characterized by high blood sugar and insulin resistance. T2DM can be prevented or delayed by a healthy diet, regular physical activity, maintaining normal body weight, and avoiding alcohol and tobacco use. Ethanol and its metabolites can cause differentiation defects in stem cells and promote inflammatory injury and carcinogenesis in several tissues. Recent studies have suggested that diabetes can be treated, and its consequences can be avoided or delayed with proper management. DM has a greater risk for several cancers, such as breast, colorectal, endometrial, pancreatic, gallbladder, renal, and liver cancer. The incidence of cancer is significantly higher in patients with DM than in those without DM. In addition to DM, alcohol abuse is also a risk factor for many cancers. We present a review of the recent studies investigating the association of both DM and alcohol abuse with cancer incidence.

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.

Chinesisation, adaptation and validation of the Chelsea Critical Care Physical Assessment Tool in critically ill patients: a cross-sectional observational study

PURPOSE

To translate and adapt the Chelsea Critical Care Physical Assessment Tool (CPAx) into Chinese version ('CPAx-Chi'), test the reliability and validity of CPAx-Chi, and verify the cut-off point for the diagnosis of intensive care unit-acquired weakness (ICU-AW).

STUDY DESIGN

Cross-sectional observational study.

METHODS

Forward and back translation, cross-cultural adaptation and pretesting of CPAx into CPAx-Chi were based on the Brislin model. Participants were recruited from the general ICU of five third-grade class-A hospitals in western China. Two hundred critically ill adult patients (median age: 53 years; 64% men) with duration of ICU stay ≥48 hours and Glasgow Coma Scale ≥11 were included in this study. Two researchers simultaneously and independently assessed eligible patients using the Medical Research Council Muscle Score (MRC-Score) and CPAx-Chi.

RESULTS

The content validity index of items was 0.889. The content validity index of scale was 0.955. Taking the MRC-Score scale as standard, the criterion validity of CPAx-Chi was r=0.758 (p<0.001) for researcher A, and r=0.65 (p<0.001) for researcher B. Cronbach's α was 0.939. The inter-rater reliability was 0.902 (p<0.001). The area under the receiver operating characteristic curves of CPAx-Chi for diagnosing ICU-AW based on MRC-Score ≤48 were 0.899 (95% CI 0.862 to 1.025) and 0.874 (95% CI 0.824 to 0.925) for researcher B. The best cut-off point for CPAx-Chi for the diagnosis of ICU-AW was 31.5. The sensitivity was 87% and specificity was 77% for researcher A, whereas it was 0.621, 31.5, 75% and 87% for researcher B, respectively. The consistency was high when taking CPAx-Chi ≤31 and MRC-Score ≤48 as the cut-off points for the diagnosis of ICU-AW. Cohen's kappa=0.845 (p=0.02) in researcher A and 0.839 (p=0.04) for researcher B.

CONCLUSIONS

CPAx-Chi demonstrated content validity, criterion-related validity and reliability. CPAx-Chi showed the best accuracy in assessment of patients at risk of ICU-AW with good sensitivity and specificity at a recommended cut-off of 31.

Prolonged Hypophosphatemia and Intensive Care After Curative Surgery of Tumor Induced Osteomalacia: A Case Report

INTRODUCTION

Rare FGF23-producing mesenchymal tumors lead to paraneoplastic tumor-induced osteomalacia (TIO) presenting with phosphate wasting, hypophosphatemia, chronic hypomineralization of the bone, fragility fractures and muscle weakness. Diagnosis of TIO requires exclusion of other etiologies and careful search for a mesenchymal tumor that often is very small and can appear anywhere in the body. Surgical removal of the tumor is the only definitive treatment of TIO. Surgical complications due to chronic hypophosphatemia are not well recognized.

CASE DESCRIPTION

The current case describes severe fragility fractures in a 58-year-old woman, who lost her ability to walk and was bedridden for two years. First, the initial diagnostic laboratory work-up did not include serum phosphorus measurements, second, the suspicion of adverse effects of pioglitazone as an underlying cause delayed correct diagnosis for at least two years. After biochemical discovery of hyperphosphaturic hypophosphatemia at a tertiary referral centre, a FGF23-producing tumor of the mandible was discovered on physical examination, and then surgically removed. Postoperatively, severe hypophosphatemia and muscle weakness prolonged the need for ventilation support, intensive care and phosphate supplementation. After two years of rehabilitation, the patient was able to walk short distances. The tumor has not recurred, and serum phosphate concentration has remained within normal limits during 3.5 years of follow-up.

CONCLUSIONS

The case report illustrates knowledge gaps in the diagnostic work-up of rare causes of low bone mass and fragility fractures. Compared to other low phosphate conditions, surgical recovery from TIO-induced hypophosphatemia warrants special attention. Increased alkaline phosphatase concentration may indicate impaired postsurgical recovery due to prolonged hypophosphatemia, underlining the need for proactive perioperative correction of hypophosphatemia.

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.

New Approaches to Critical Illness Polyneuromyopathy: High-Resolution Neuromuscular Ultrasound Characteristics and Cytokine Profiling

Background

Diagnosis of intensive care unit acquired weakness (ICUAW) is challenging. Pathogenesis of underlying critical illness polyneuromyopathy (CIPNM) remains incompletely understood. This exploratory study investigated whether longitudinal neuromuscular ultrasound examinations and cytokine analyses in correlation to classical clinical and electrophysiological assessment contribute to the understanding of CIPNM.

Methods

Intensive care unit patients were examined every 7 days until discharge from hospital. Clinical status, nerve conduction studies, electromyography as well as ultrasound of peripheral nerves and tibial anterior muscle were performed. Cytokine levels were analyzed by a bead-based multiplex assay system.

Results

Of 248 screened patients, 35 patients were included at median of 6 days (IQR: 8) after admission to intensive care unit. Axonal damage was the main feature of CIPNM. At the peak of CIPNM (7 days after inclusion), nerve ultrasound showed cross-sectional area increase of tibial nerve as a sign of inflammatory edema as well as hypoechoic nerves as a possible sign of inflammation. Cytokine analyses showed signs of monocyte and macrophage activation at this stage. Fourteen days after inclusion, cytokines indicated systemic immune response as well as profiles associated to neovascularization and regeneration.

Conclusions

Exploratory neuromuscular ultrasound and cytokine analyses showed signs of inflammation like macrophage and monocyte activation at the peak of CIPNM followed by a systemic immune response parallel to axonal damage. This underlines the role of both axonal damage and inflammation in pathogenesis of CIPNM.

Electronic supplementary material

The online version of this article (10.1007/s12028-020-01148-2) contains supplementary material, which is available to authorized users.

ICU-acquired weakness

Critically ill patients often acquire neuropathy and/or myopathy labeled ICU-acquired weakness. The current insights into incidence, pathophysiology, diagnostic tools, risk factors, short- and long-term consequences and management of ICU-acquired weakness are narratively reviewed. PubMed was searched for combinations of “neuropathy”, “myopathy”, “neuromyopathy”, or “weakness” with “critical illness”, “critically ill”, “ICU”, “PICU”, “sepsis” or “burn”. ICU-acquired weakness affects limb and respiratory muscles with a widely varying prevalence depending on the study population. Pathophysiology remains incompletely understood but comprises complex structural/functional alterations within myofibers and neurons. Clinical and electrophysiological tools are used for diagnosis, each with advantages and limitations. Risk factors include age, weight, comorbidities, illness severity, organ failure, exposure to drugs negatively affecting myofibers and neurons, immobility and other intensive care-related factors. ICU-acquired weakness increases risk of in-ICU, in-hospital and long-term mortality, duration of mechanical ventilation and of hospitalization and augments healthcare-related costs, increases likelihood of prolonged care in rehabilitation centers and reduces physical function and quality of life in the long term. RCTs have shown preventive impact of avoiding hyperglycemia, of omitting early parenteral nutrition use and of minimizing sedation. Results of studies investigating the impact of early mobilization, neuromuscular electrical stimulation and of pharmacological interventions were inconsistent, with recent systematic reviews/meta-analyses revealing no or only low-quality evidence for benefit. ICU-acquired weakness predisposes to adverse short- and long-term outcomes. Only a few preventive, but no therapeutic, strategies exist. Further mechanistic research is needed to identify new targets for interventions to be tested in adequately powered RCTs.

[Muscle in critically ill patients]

Introduction

Polyneuropathy in the critically ill patient was defined as a generalized weakness, acquired during Intensive Care Unit (ICU) admittance and attributed to lesion of the peripheral nerve. Research in this field progressed over time, revealing the crucial role of muscle injury in this disease, to the point of re-naming the disorder as ICU adquired weakness (ICUAW). Muscle damage is common in severe illness, and may be classified in qualitative (weakness) or quantitative (decrease in mass) muscle loss. The most frequent scenario in these patients, is simultaneous change in quality and quantity of muscle; resulting in a challenging and delayed recovery during hospital admittance and after discharge. Multiple causes have been identified in the pathogenesis of this disorder, such as: prolonged bed rest, inadequate intake of nutrients and exposure to drugs that affect muscle structure and contraction. The assessment of muscle mass using images provided by ultrasound or computerized tomography may guide follow up. The prevention and treatment of ICUAW requires a multimodal approach: early mobilization and exercise, appropriate nutritional prescription and, occasionally, muscle protein synthesis stimulants. Further studies will clarify more aspects regarding critically ill patients suffering from muscle injury, in order to better address prevention and treatment of ICUAW.

Nutrition therapy and critical illness: practical guidance for the ICU, post-ICU, and long-term convalescence phases

BACKGROUND

Although mortality due to critical illness has fallen over decades, the number of patients with long-term functional disabilities has increased, leading to impaired quality of life and significant healthcare costs. As an essential part of the multimodal interventions available to improve outcome of critical illness, optimal nutrition therapy should be provided during critical illness, after ICU discharge, and following hospital discharge.

METHODS

This narrative review summarizes the latest scientific insights and guidelines on ICU nutrition delivery. Practical guidance is given to provide optimal nutrition therapy during the three phases of the patient journey.

RESULTS

Based on recent literature and guidelines, gradual progression to caloric and protein targets during the initial phase of ICU stay is recommended. After this phase, full caloric dose can be provided, preferably based on indirect calorimetry. Phosphate should be monitored to detect refeeding hypophosphatemia, and when occurring, caloric restriction should be instituted. For proteins, at least 1.3 g of proteins/kg/day should be targeted after the initial phase. During the chronic ICU phase, and after ICU discharge, higher protein/caloric targets should be provided preferably combined with exercise. After ICU discharge, achieving protein targets is more difficult than reaching caloric goals, in particular after removal of the feeding tube. After hospital discharge, probably very high-dose protein and calorie feeding for prolonged duration is necessary to optimize the outcome. High-protein oral nutrition supplements are likely essential in this period. Several pharmacological options are available to combine with nutrition therapy to enhance the anabolic response and stimulate muscle protein synthesis.

CONCLUSIONS

During and after ICU care, optimal nutrition therapy is essential to improve the long-term outcome to reduce the likelihood of the patient to becoming a "victim" of critical illness. Frequently, nutrition targets are not achieved in any phase of recovery. Personalized nutrition therapy, while respecting different targets during the phases of the patient journey after critical illness, should be prescribed and monitored.

Repetitive vascular occlusion stimulus (RVOS) versus standard care to prevent muscle wasting in critically ill patients (ROSProx):a study protocol for a pilot randomised controlled trial

BACKGROUND

Forty per cent of critically ill patients are affected by intensive care unit-acquired weakness (ICU-AW), to which skeletal muscle wasting makes a substantial contribution. This can impair outcomes in hospital, and can cause long-term physical disability after hospital discharge. No effective mitigating strategies have yet been identified. Application of a repetitive vascular occlusion stimulus (RVOS) a limb pressure cuff inducing brief repeated cycles of ischaemia and reperfusion, can limit disuse muscle atrophy in both healthy controls and bed-bound patients recovering from knee surgery. We wish to determine whether RVOS might be effective in mitigating against muscle wasting in the ICU. Given that RVOS can also improve vascular function in healthy controls, we also wish to assess such effects in the critically ill. We here describe a pilot study to assess whether RVOS application is safe, tolerable, feasible and acceptable for ICU patients.

METHODS

This is a randomised interventional feasibility trial. Thirty-two ventilated adult ICU patients with multiorgan failure will be recruited within 48 h of admission and randomised to either the intervention arm or the control arm. Intervention participants will receive RVOS twice daily (except only once on day 1) for up to 10 days or until ICU discharge. Serious adverse events and tolerability (pain score) will be recorded; feasibility of trial procedures will be assessed against pre-specified criteria and acceptability by semi-structured interview. Together with vascular function, muscle mass and quality will be assessed using ultrasound and measures of physical function at baseline, on days 6 and 11 of study enrolment, and at ICU and hospital discharge. Blood and urine biomarkers of muscle metabolism, vascular function, inflammation and DNA damage/repair mechanism will also be analysed. The Health questionnaire will be completed 3 months after hospital discharge.

DISCUSSION

If this study demonstrates feasibility, the derived data will be used to inform the design (and sample size) of an appropriately-powered prospective trial to clarify whether RVOS can help preserve muscle mass/improve vascular function in critically ill patients.

TRIAL REGISTRATION

ISRCTN Registry, ISRCTN44340629. Registered on 26 October 2017.

Major publications in the critical care pharmacotherapy literature: January-December 2016

PURPOSE

To summarize select critical care pharmacotherapy guidelines and studies published in 2016.

SUMMARY

The Critical Care Pharmacotherapy Literature Update (CCPLU) Group screened 31 journals monthly for relevant pharmacotherapy articles and selected 107 articles for review over the course of 2016. Of those included in the monthly CCPLU, three guidelines and seven primary literature studies are reviewed here. The guideline updates included are as follows: hospital-acquired pneumonia and ventilator-associated pneumonia management, sustained neuromuscular blocking agent use, and reversal of antithrombotics in intracranial hemorrhage (ICH). The primary literature summaries evaluate the following: dexmedetomidine for delirium prevention in post-cardiac surgery, dexmedetomidine for delirium management in mechanically ventilated patients, high-dose epoetin alfa after out-of-hospital cardiac arrest, ideal blood pressure targets in ICH, hydrocortisone in severe sepsis, procalcitonin-guided antibiotic de-escalation, and empiric micafungin therapy.

CONCLUSION

The review provides a synopsis of select pharmacotherapy publications in 2016 applicable to clinical practice.

What factors influence protein synthesis and degradation in critical illness?

PURPOSE OF REVIEW

The optimal approach to improve protein metabolism in critical illness is not yet fully defined. Here, we have summarized recent literature dealing with the main catabolic and anabolic factors influencing protein kinetics in acute hypercatabolic patients.

RECENT FINDINGS

Protein/amino acid intake levels should be adapted to type and severity of illness, keeping in mind that energy overfeeding is associated with poor outcome. A number of anticatabolic nutraceuticals and drugs have been tested in acute patients. The encouraging results have been obtained with β-hydroxy-β-methylbutyrate, omega-3 fatty acids, oxandrolone, propranolol, and metformin. Their efficacy and lack of side-effects need to be confirmed. Physical therapy, including muscle electro-stimulation, appears a very promising intervention, both effective and safe.

SUMMARY

Protein catabolism can be minimized in acute patients by adequate nutritional support, early mobilization, and, possibly, pharmacological and nutraceutical interventions. A combination of these strategies should be tested in randomized controlled trials.

Interventions to reduce cognitive impairments following critical illness: a topical systematic review

BACKGROUND

Critical illness is associated with cognitive impairments. Effective treatment or prevention has not been established. The aim of this review was to create a systematic summary of the current evidence concerning clinical interventions during intensive care admission to reduce cognitive impairments after discharge.

METHODS

Medline, Embase, Cochrane Central, PsycInfo and Cinahl were searched. Inclusion criteria were studies assessing the effect of interventions during intensive care admission on cognitive function in adult patients. Studies were excluded if they were reviews or reported solely on survivors of cardiac arrest, stroke or traumatic brain injury.

RESULTS

Of 4877 records were identified. Seven studies fulfilled the eligibility criteria. The interventions described covered strategies for enteral nutrition, fluids, sedation, weaning, mobilization, cognitive activities, statins and sleep quality improvement. Data were synthesized to provide an overview of interventions, quality, follow-up assessments and neuropsychological outcomes.

CONCLUSION

None of the interventions had significant positive effects on cognitive impairments following critical illness. Quality was negatively affected by study limitations, imprecision and indirectness in evidence. Clinical research on cognition is feasible, but large, well designed trials with a specific aim at reducing cognitive impairments are needed.