The role of future longitudinal studies in ICU survivors: understanding determinants and pathophysiology of weakness and neuromuscular dysfunction

Factors Determining the Functional State of Cardiac Surgery Patients with Complicated Postoperative Period

The purpose of this work was to study the factors determining the functional state of cardiac surgery patients with a complicated postoperative period upon discharge from the hospital. This observational study included 60 patients who underwent cardiac surgery with a complicated postoperative course and with a prolonged intensive care unit stay of more than 72 h. We assessed handgrip and lower-extremity muscle strength and the six-minute walk test (6MWT) distance 3 days after the surgery and at discharge from the hospital. Some patients (53%) additionally underwent a course of neuromuscular electrostimulation (NMES). Two groups of patients were formed: first (6MWT distance at discharge of more than 300 m) and second groups (6MWT distance of 300 m or less). The patients of the second group had less lower-extremity muscle strength and handgrip strength on the third postoperative day, a longer aortic clamping time and a longer stay in the intensive care unit. Independent predictors of decreased exercise tolerance at discharge were body mass index, foot extensor strength and baseline 6MWT distance in the general group, duration of cardiopulmonary bypass in the NMES group and in the general group, and age in the NMES group. Thus, the muscle status on the third postoperative day was one of the independent factors associated with the 6MWT distance at discharge in the general group, but not in patients who received NMES. It is advisable to use these results in patients with complications after cardiac surgery with the use of NMES rehabilitation.

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.

Rehabilitation and early mobilization in the critical patient: systematic review

[Purpose] To review the literature that examines rehabilitation and early mobilization and that involves different practices (effects of interventions) for the critically ill patient. [Materials and Methods] A PRISMA-Systematic review has been conducted based on different data sources: Biblioteca Virtual en Salud, CINHAL, Pubmed, Scopus, and Web of Science were used to identify randomized controlled trials, crossover trials, and case-control studies. [Results] Eleven studies were included. Early rehabilitation had no significant effect on the length of stay and number of cases of Intensive Care Unit Acquired Weaknesses. However, early rehabilitation had a significant effect on the functional status, muscle strength, mechanical ventilation duration, walking ability at discharge, and health quality of life. [Conclusion] Rehabilitation and early mobilization are associated with an increased probability of walking more distance at discharge. Early rehabilitation is associated with an increase in functional capacity and muscle strength, an improvement in walking distance and better perception of the health-related quality of life. Cycloergometer and electrical stimulation can be used to maintain muscle strength. Further research is needed to establish stronger evidences.

Effectiveness of an early mobilization program on functional capacity after coronary artery bypass surgery: A randomized controlled trial protocol

Background:

Muscle atrophy and prolonged inactivity are associated with an increased sensation of fatigue and reduced functional capacity in the postoperative period in patients undergoing coronary artery bypass grafting. Cardiac rehabilitation after hospital discharge is highly recommended and contributes to improvement in functional capacity and quality of life. However, few studies have evaluated the effectiveness of early mobilization protocols during hospitalization on the patterns of physical activity and functional capacity after coronary artery bypass grafting.

Objective:

To investigate the effectiveness of an early mobilization program on the functional capacity of patients undergoing coronary artery bypass grafting in the short and long term.

Methods:

This is a prospective, randomized, controlled, single-blind trial protocol that will evaluate 66 consecutive patients undergoing coronary artery bypass grafting. Patients will be randomized into two training groups: the control group (N = 33), which will perform breathing exercises and the intervention group (N = 33), which will perform breathing exercises and aerobic exercises. The groups will receive treatment from first to the seventh postoperative day, twice daily. In the preoperative period, the following outcomes will be assessed: physical activity level (Baecke Questionnaire), Functional Independence Measure, and functional capacity (6-min walking test). Functional capacity will be reassessed after the 7th and 60th postoperative day. Pulmonary complications and length of hospital stay will also be evaluated. Statistical analysis will be calculated using linear mixed models and will be based on intention-to-treat. The level of significance will be set at α = 5%.

Quality of life of critically ill patients in a developing country: a prospective longitudinal study

[Purpose] To evaluate the quality of life of critical illness survivors in a developing country over the time after hospital discharge and to assess the influence of clinical variables on quality of life. [Subjects and Methods] A prospective longitudinal study was conducted in a large, tertiary, public hospital in Sao Paulo, Brazil. We included patients ≥18 years old, hospitalized in the intensive care unit with ≥24 hours of invasive mechanical ventilation. Quality of life was assessed using the Medical Outcomes Study 36-Item Short Form Health Survey, which was applied by telephone interview at the first, third and sixth months after hospital discharge. [Results] 75 patients were included in the study. Quality of life improved progressively after hospital discharge; role-physical was the most compromised domain. The physical component was influenced by the age. Quality of life was not influenced by Apache II categorization, length of invasive mechanical ventilation, intensive care unit stay or hospital stay. [Conclusion] Survivors of critical illness in a developing country present poor quality of life, which improves over time. Age influenced the physical component of quality of life.

Intensive care unit acquired weakness in children: Critical illness polyneuropathy and myopathy

BACKGROUND AND AIMS

Intensive care unit acquired weakness (ICUAW) is a common occurrence in patients who are critically ill. It is most often due to critical illness polyneuropathy (CIP) or to critical illness myopathy (CIM). ICUAW is increasingly being recognized partly as a consequence of improved survival in patients with severe sepsis and multi-organ failure, partly related to commonly used agents such as steroids and muscle relaxants. There have been occasional reports of CIP and CIM in children, but little is known about their prevalence or clinical impact in the pediatric population. This review summarizes the current understanding of pathophysiology, clinical presentation, diagnosis and treatment of CIP and CIM in general with special reference to published literature in the pediatric age group.

SUBJECTS AND METHODS

Studies were identified through MedLine and Embase using relevant MeSH and Key words. Both adult and pediatric studies were included.

RESULTS

ICUAW in children is a poorly described entity with unknown incidence, etiology and unclear long-term prognosis.

CONCLUSIONS

Critical illness polyneuropathy and myopathy is relatively rare, but clinically significant sequelae of multifactorial origin affecting morbidity, length of intensive care unit (ICU) stay and possibly mortality in critically ill children admitted to pediatric ICU.

A physical function test for use in the intensive care unit: validity, responsiveness, and predictive utility of the physical function ICU test (scored)

BACKGROUND

Several tests have recently been developed to measure changes in patient strength and functional outcomes in the intensive care unit (ICU). The original Physical Function ICU Test (PFIT) demonstrates reliability and sensitivity.

OBJECTIVE

The aims of this study were to further develop the original PFIT, to derive an interval score (the PFIT-s), and to test the clinimetric properties of the PFIT-s.

DESIGN

A nested cohort study was conducted.

METHODS

One hundred forty-four and 116 participants performed the PFIT at ICU admission and discharge, respectively. Original test components were modified using principal component analysis. Rasch analysis examined the unidimensionality of the PFIT, and an interval score was derived. Correlations tested validity, and multiple regression analyses investigated predictive ability. Responsiveness was assessed using the effect size index (ESI), and the minimal clinically important difference (MCID) was calculated.

RESULTS

The shoulder lift component was removed. Unidimensionality of combined admission and discharge PFIT-s scores was confirmed. The PFIT-s displayed moderate convergent validity with the Timed "Up & Go" Test (r=-.60), the Six-Minute Walk Test (r=.41), and the Medical Research Council (MRC) sum score (rho=.49). The ESI of the PFIT-s was 0.82, and the MCID was 1.5 points (interval scale range=0-10). A higher admission PFIT-s score was predictive of: an MRC score of ≥48, increased likelihood of discharge home, reduced likelihood of discharge to inpatient rehabilitation, and reduced acute care hospital length of stay.

LIMITATIONS

Scoring of sit-to-stand assistance required is subjective, and cadence cutpoints used may not be generalizable.

CONCLUSIONS

The PFIT-s is a safe and inexpensive test of physical function with high clinical utility. It is valid, responsive to change, and predictive of key outcomes. It is recommended that the PFIT-s be adopted to test physical function in the ICU.

Early Physical Rehabilitation in the ICU: A Review for the Neurohospitalist

Advances in critical care have resulted in improved intensive care unit (ICU) mortality. However, improved ICU survival has resulted in a growing number of ICU survivors living with long-term sequelae of critical illness, such as impaired physical function and quality of life (QOL). In addition to critical illness, prolonged bed rest and immobility may lead to severe physical deconditioning and loss of muscle mass and muscle weakness. ICU-acquired weakness is associated with increased duration of mechanical ventilation and weaning, longer ICU and hospital stay, and increased mortality. These physical impairments may last for years after ICU discharge. Early Physical Medicine and Rehabilitation (PM&R) interventions in the ICU may attenuate or prevent the weakness and physical impairments occurring during critical illness. This article reviews the evidence regarding safety, feasibility, barriers, and benefits of early PM&R interventions in ICU patients and discusses the limited existing data on early PM&R in the neurological ICU and future directions for early PM&R in the ICU.

Airflow distribution with manual hyperinflation as assessed through gamma camera imaging: a crossover randomised trial

OBJECTIVES

Manual hyperinflation (MHI) has been shown to improve lung compliance, reduce airway resistance, and enhance secretion removal and peak expiratory flow. The aims of this study were to investigate whether there is a difference in airflow distribution through patients' lungs when using the Laerdal and Mapleson-C circuits at a set level of positive end-expiratory pressure (PEEP), and to establish whether differences in lung compliance and haemodynamic status exist when patients are treated with both these MHI circuits.

DESIGN

Crossover randomised controlled trial.

SETTING

Adult multidisciplinary intensive care unit (ICU) at an academic hospital.

PARTICIPANTS

Fifteen adult patients were recruited and served as their own controls.

INTERVENTION

In the Nuclear Medicine Department, MHI with PEEP 7.5 cmH(2)O was performed in the supine position (Day 1) with either Laerdal or Mapleson-C circuits, in a random order, while technetium-99m (Tc-99m) aerosol was administered and images were taken with a gamma camera. Changes in heart rate (HR), mean arterial pressure (MAP) and dynamic lung compliance (C(D)) were documented at baseline, immediately after return to ICU, and 10, 20 and 30 minutes after return to ICU. The alternative circuit was used on Day 2.

RESULTS

Tc-99m deposition was greater in the right lung field (62% and 63% for Laerdal and Mapleson-C circuits, respectively) than the left lung field (38% and 37%, respectively) for all patients, and least deposition occurred in the left lower segments (6% and 6%, respectively). No differences in Tc-99m deposition in the lungs, HR, MAP or C(D) were noted between the two MHI circuits.

CONCLUSION

Airflow distribution through patients' lungs was similar when the Laerdal and Mapleson-C MHI circuits were compared using a set level of PEEP in the supine position.

Neuromuscular disorders in critically ill patients: review and update

Neuromuscular disorders that are diagnosed in the intensive care unit (ICU) usually cause substantial limb weakness and contribute to ventilatory dysfunction. Although some lead to ICU admission, ICU-acquired disorders, mainly critical illness myopathy (CIM) and critical illness polyneuropathy (CIP), are more frequent and are associated with considerable morbidity. Approximately 25% to 45% of patients admitted to the ICU develop CIM, CIP, or both. Their clinical features often overlap; therefore, nerve conduction studies and electromyography are particularly helpful diagnostically, and more sophisticated electrodiagnostic studies and histopathologic evaluation are required in some circumstances. A number of prospective studies have identified risk factors for CIP and CIM, but their limitations often include the inability to separate CIM from CIP. Animal models reveal evidence of a channelopathy in both CIM and CIP, and human studies also identified axonal degeneration in CIP and myosin loss in CIM. Outcomes are variable. They tend to be better with CIM, and some patients have longstanding disabilities. Future studies of well-characterized patients with CIP and CIM should refine our understanding of risk factors, outcomes, and pathogenic mechanisms, leading to better interventions.

Manual muscle strength testing of critically ill patients: feasibility and interobserver agreement

INTRODUCTION

It has been proposed that intensive care unit (ICU)-acquired weakness (ICUAW) should be assessed using the sum of manual muscle strength test scores in 12 muscle groups (the sum score). This approach has been tested in patients with Guillain-Barré syndrome, yet little is known about the feasibility or test characteristics in other critically ill patients. We studied the feasibility and interobserver agreement of this sum score in a mixed cohort of critically ill and injured patients.

METHODS

We enrolled patients requiring more than 3 days of mechanical ventilation. Two observers performed systematic strength assessments of each patient. The primary outcome measure was interobserver agreement of weakness as a binary outcome (ICUAW is sum score less than 48; "no ICUAW" is a sum score greater than or equal to 48) using the Cohen's kappa statistic.

RESULTS

We identified 135 patients who met the inclusion criteria. Most were precluded from study participation by altered mental status or polytrauma. Thirty-four participants were enrolled, and 30 of these individuals completed assessments conducted by both observers. Six met the criteria for ICUAW recorded by at least one observer. The observers agreed on the diagnosis of ICUAW for 93% of participants (Cohen's kappa = 0.76; 95% confidence interval (CI), 0.44 to 1.0). Observer agreement was fair in the ICU (Cohen's kappa = 0.38), and agreement was perfect after ICU discharge (Cohen's kappa = 1.0). Absolute values of sum scores were similar between observers (intraclass correlation coefficient 0.83; 95% CI, 0.67 to 0.91), but they differed between observers by six points or more for 23% of the participants.

CONCLUSIONS

Manual muscle testing (MMT) during critical illness was not possible for most patients because of coma, delirium and/or injury. Among patients who were able to participate in testing, we found that interobserver agreement regarding ICUAW was good, particularly when evaluated after ICU discharge. MMT is insufficient for early detection of ICU-acquired neuromuscular dysfunction in most patients and may be unreliable during critical illness.

Critical illness polyneuropathy and myopathy in the intensive care unit

Critical illness polyneuropathy (CIP) and critical illness myopathy (CIM) are major complications that occur in severely ill patients who require intensive care treatment. CIP and CIM affect the limb and respiratory muscles, and, as a consequence, they characteristically complicate weaning from the ventilator, increase the length of stay on the intensive care unit, and prolong physical rehabilitation. The basic pathophysiology of both disorders is complex and involves metabolic, inflammatory and bioenergetic alterations. It is unclear at present whether CIP and CIM are distinct entities, or whether they just represent different 'organ' manifestations of a common pathophysiological mechanism. This article provides an overview of the clinical and diagnostic features of CIP and CIM and discusses current pathophysiological and therapeutic concepts relating to these neuromuscular disorders.

Critical illness neuromyopathy and muscle weakness in patients in the intensive care unit

Neuromuscular complications of critical illness are common and can be severe and persistent in some patients. Neuromyopathy from critical illness and disuse atrophy from prolonged immobility contribute to muscle weakness acquired while in the intensive care unit. Although various risk factors (eg, severity of illness, corticosteroids, neuromuscular blocking agents) have been implicated in critical illness neuromyopathy (CINM), the evidence supporting these associations is inconsistent. Hyperglycemia may be an important risk factor for CINM, with tight glycemic control through intensive insulin therapy reducing the incidence of CINM. Early mobility in the intensive care unit may minimize disuse atrophy and possibly CINM, through exercise training and its anti-inflammatory effects. Although emerging data have demonstrated the safety, feasibility, and benefit of early mobility in critically ill patients, randomized controlled trials are needed to thoroughly evaluate its potential benefits on patients' muscle strength, physical function, and quality of life. Future studies are needed to elucidate the multiple mechanisms by which immobility, CINM, and other aspects of critical illness lead to muscle loss and neuromuscular dysfunction.

Measurement of muscle strength in the intensive care unit

Traditional (indirect) techniques, such as electromyography and nerve conduction velocity measurement, do not reliably predict intensive care unit-acquired muscle weakness and its clinical consequences. Therefore, quantitative assessment of skeletal muscle force is important for diagnosis of intensive care unit-acquired motor dysfunction. There are a number of ways for assessing objectively muscle strength, which can be categorized as techniques that quantify maximum voluntary contraction force and those that assess evoked (stimulated) muscle force. Important factors that limit the repetitive evaluation of maximum voluntary contraction force in intensive care unit patients are learning effects, pain during muscular contraction, and alteration of consciousness.The selection of the appropriate muscle is crucial for making adequate predictions of a patient's outcome. The upper airway dilators are much more susceptible to a decrease in muscle strength than the diaphragm, and impairment of upper airway patency is a key mechanism of extubation failure in intensive care unit patients. Data suggest that the adductor pollicis muscle is an appropriate reference muscle to predict weakness of muscles that are typically affected by intensive care unit-acquired weakness, i.e., upper airway as well as extremity muscles. Stimulated (evoked) force of skeletal muscles, such as the adductor pollicis, can be assessed repetitively, independent of brain function, even in heavily sedated patients during high acuity of their disease.

Bench-to-bedside review: mobilizing patients in the intensive care unit--from pathophysiology to clinical trials

As the mortality from critical illness has improved in recent years, there has been increasing focus on patient outcomes after hospital discharge. Neuromuscular weakness acquired in the intensive care unit (ICU) is common, persistent, and often severe. Immobility due to prolonged bed rest in the ICU may play an important role in the development of ICU-acquired weakness. Studies in other patient populations have demonstrated that moderate exercise is beneficial in altering the inflammatory milieu associated with immobility, and in improving muscle strength and physical function. Recent studies have demonstrated that early mobility in the ICU is safe and feasible, with a potential reduction in short-term physical impairment. However, early mobility requires a significant change in ICU practice, with reductions in heavy sedation and bed rest. Further research is required to determine whether early mobility in the ICU can improve patients' short-term and long-term outcomes.