Paresis following mechanical ventilation

Autophagy ablation in skeletal muscles worsens sepsis-induced muscle wasting, impairs whole-body metabolism, and decreases survival

Septic patients frequently develop skeletal muscle wasting and weakness, resulting in severe clinical consequences and adverse outcomes. Sepsis triggers sustained induction of autophagy, a key cellular degradative pathway, in skeletal muscles. However, the impact of enhanced autophagy on sepsis-induced muscle dysfunction remains unclear. Using an inducible and muscle-specific Atg7 knockout mouse model (Atg7iSkM-KO), we investigated the functional importance of skeletal muscle autophagy in sepsis using the cecal ligation and puncture model. Atg7iSkM-KO mice exhibited a more severe phenotype in response to sepsis, marked by severe muscle wasting, hypoglycemia, higher ketone levels, and a decreased in survival as compared to mice with intact Atg7. Sepsis and Atg7 deletion resulted in the accumulation of mitochondrial dysfunction, although sepsis did not further worsen mitochondrial dysfunction in Atg7iSkM-KO mice. Overall, our study demonstrates that autophagy inactivation in skeletal muscles triggers significant worsening of sepsis-induced muscle and metabolic dysfunctions and negatively impacts survival.

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.

A randomized controlled trial to determine whether beta-hydroxy-beta-methylbutyrate and/or eicosapentaenoic acid improves diaphragm and quadriceps strength in critically Ill mechanically ventilated patients

Background

Intensive care unit acquired weakness is a serious problem, contributing to respiratory failure and reductions in ambulation. Currently, there is no pharmacological therapy for this condition. Studies indicate, however, that both beta-hydroxy-beta-methylbutyrate (HMB) and eicosapentaenoic acid (EPA) increase muscle function in patients with cancer and in older adults. The purpose of this study was to determine whether HMB and/or EPA administration would increase diaphragm and quadriceps strength in mechanically ventilated patients.

Methods

Studies were performed on 83 mechanically ventilated patients who were recruited from the Medical Intensive Care Units at the University of Kentucky. Diaphragm strength was assessed as the trans-diaphragmatic pressure generated by supramaximal magnetic phrenic nerve stimulation (PdiTw). Quadriceps strength was assessed as leg force generated by supramaximal magnetic femoral nerve stimulation (QuadTw). Diaphragm and quadriceps thickness were assessed by ultrasound. Baseline measurements of muscle strength and size were performed, and patients were then randomized to one of four treatment groups (placebo, HMB 3 gm/day, EPA 2 gm/day and HMB plus EPA). Strength and size measurements were repeated 11 days after study entry. ANCOVA statistical testing was used to compare variables across the four experimental groups.

Results

Treatments failed to increase the strength and thickness of either the diaphragm or quadriceps when compared to placebo. In addition, treatments also failed to decrease the duration of mechanical ventilation after study entry.

Conclusions

These results indicate that a 10-day course of HMB and/or EPA does not improve skeletal muscle strength in critically ill mechanically ventilated patients. These findings also confirm previous reports that diaphragm and leg strength in these patients are profoundly low. Additional studies will be needed to examine the effects of other anabolic agents and innovative forms of physical therapy.

Trial registration: ClinicalTrials.gov, NCT01270516. Registered 5 January 2011, https://clinicaltrials.gov/ct2/show/NCT01270516?term=Supinski&draw=2&rank=4.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03737-9.

Ambulatory Status Is Associated With Successful Discharge Home in Survivors of Critical Illness

BACKGROUND

Survivors of prolonged ICU admissions are bedridden and immobilized for an extended period of time. These patients often are discharged to long-term acute care hospitals (LTACHs) for continued medical care and rehabilitation. Early ambulation has been associated with improved functional outcomes and lower readmission rates in hospitalized patients. The aim of this study was to determine the association between ambulatory status and discharge disposition in survivors of prolonged ICU stays who were admitted to an LTACH.

METHODS

We performed a retrospective cohort study of 285 survivors of prolonged ICU stays who were admitted to a university-affiliated LTACH facility from 2010 to 2013. Outcomes of interest included comparing the relationship between ambulatory status and disposition status (ie, home vs acute rehabilitation facility, nursing home, readmission to an ICU, or death).

RESULTS

The mean age of our cohort was 59.0 ± 15.3 y, with 129 (45%) males, 148 (52%) African-American, 123 (43%) white, and 14 (5%) of subjects other races. Most of these subjects were transferred from a medical ICU (68%). The median ICU and LTACH lengths of stay were 25.5 (13-38.8) d and 34.0 (14-64) d, respectively. Thirty-eight (13.3%) subjects were discharged home, 25 (8.7%) to an acute rehabilitation facility, 70 (24.6%) to a nursing home, 139 (48.8%) were readmitted to an ICU, and 13 (4.6%) died. Of 285 total subjects, 74 (26%) ambulated during physical therapy, while 211 (74%) subjects never ambulated. Of those who ambulated, 24 (32.4%) went home, whereas 14 of 211 (6.6%) subjects who did not ambulate went home (P < .001).

CONCLUSIONS

The ability to ambulate was associated with a greater likelihood of being discharged home in survivors of prolonged ICU stays who were admitted to an LTACH. These results suggest that mobility training for survivors of prolonged ICU stays in LTACH facilities should be strongly emphasized to improve their likelihood of being discharged home.

Corticosteroids and neuromuscular blockers in development of critical illness neuromuscular abnormalities: A historical review

Weakness is common in critically ill patients, associated with prolonged mechanical ventilation and increased mortality. Corticosteroids and neuromuscular blockade (NMB) administration have been implicated as etiologies of acquired weakness in the intensive care unit. Medical literature since the 1970s is replete with case reports and small case series of patients with weakness after receiving high-dose corticosteroids, prolonged NMB, or both. Several risk factors for weakness appear in the early literature, including large doses of steroids, the dose and duration of NMB, hyperglycemia, and the duration of mechanical ventilation. With improved quality of data, however, the association between weakness and steroids or NMB wanes. This may reflect changes in clinical practice, such as a reduction in steroid dosing, use of cisatracurium besylate instead of aminosteroid NMBs, improved glycemic control, or trends in minimizing mechanical ventilatory support. Thus, based on the most recent and high-quality literature, neither corticosteroids in commonly used doses nor NMB is associated with increased duration of mechanical ventilation, the greatest morbidity of weakness. Minimizing ventilator support as soon as the patient's condition allows may be associated with a reduction in weakness-related morbidity.

Acquired Muscle Weakness in the Surgical Intensive Care Unit

Muscle weakness is common in the surgical intensive care unit (ICU). Low muscle mass at ICU admission is a significant predictor of adverse outcomes. The consequences of ICU-acquired muscle weakness depend on the underlying mechanism. Temporary drug-induced weakness when properly managed may not affect outcome. Severe perioperative acquired weakness that is associated with adverse outcomes (prolonged mechanical ventilation, increases in ICU length of stay, and mortality) occurs with persistent (time frame: days) activation of protein degradation pathways, decreases in the drive to the skeletal muscle, and impaired muscular homeostasis. ICU-acquired muscle weakness can be prevented by early treatment of the underlying disease, goal-directed therapy, restrictive use of immobilizing medications, optimal nutrition, activating ventilatory modes, early rehabilitation, and preventive drug therapy. In this article, the authors review the nosology, epidemiology, diagnosis, and prevention of ICU-acquired weakness in surgical ICU patients.

Factors associated with receipt of physical therapy consultation in patients requiring prolonged mechanical ventilation

BACKGROUND/INTRODUCTION

Mobilization of critically ill patients in the intensive care unit is associated with improved function at hospital discharge and reduced duration of mechanical ventilation (MV). Few studies, however, focus on physical therapy (PT) in patients on prolonged mechanical ventilation (PMV) despite their high risk of immobility and poor outcomes.

OBJECTIVE/AIMS

The objective of this study was to identify factors associated with the receipt of PT consultation among patients requiring PMV. We hypothesized that key factors including age, severity of illness, and presence of a tracheostomy are associated with PT consultation.

METHODS

This was a retrospective cohort study of adults on MV for 14 days or longer for acute respiratory failure at an academic medical center. Primary outcome was PT consultation by day 14 of MV. We examined associations between the following key predictors chosen a priori and PT consultation: age, tracheostomy, illness severity, oxygenation status, shock, hemodialysis, and medical service using multivariable logistic regression. Wilcoxon rank sum testing was used to test relationship between sedation and PT.

RESULTS

We identified 175 patients requiring PMV at our institution. Most were middle-aged (mean, 49.7 [SD, 18.5] years old) men (65%) with high illness severity (mean Acute Physiology and Chronic Health Evaluation III score, 86 [SD, 40]). Less than half of all patients requiring PMV (78/175, 45%) received PT consultation in the intensive care unit, and most failed to progress with therapy beyond range-of-motion exercises (85%). Failure to progress was associated with level of sedation (med Ramsay score 4.5 [interquartile range, 3-6] vs 3.5 [interquartile range, 3-5]; P = .01). Presence of a tracheostomy and prehospital nonambulatory status were associated with receipt of PT by day 14 of MV (odds ratio, 6.94 and 3.42, respectively; P ≤ .05).

CONCLUSIONS

In our study, we found that PT for PMV patients occurs infrequently and is generally of low intensity. Level of sedation, presence of a tracheostomy, and prehospital nonambulatory status were associated with receipt of PT consultation by day 14 of MV.

Muscle atrophy in intensive care unit patients

Introduction:

The muscle atrophy is one of the most important and frequent problems observed in patients in Intensive Care Units. The term describes the disorder in the structure and in the function of the muscle while incidence rates range from 25-90 % in patients with prolonged hospitalization.

Purpose:

This is a review containing all data related to the issue of muscle atrophy and is especially referred to its causes and risk factors. The importance of early diagnosis and early mobilization are also highlighted in the study.

Material and methods:

a literature review was performed on valid databases such as Scopus, PubMed, Cinhal for the period 2000-2013 in English language. The following keywords were used: loss of muscle mass, ICU patients, immobilization, bed rest.

Results:

From the review is concluded that bed rest and immobilization in order to reduce total energy costs, are the main causes for the appearance of the problem. The results of the reduction of the muscle mass mainly affect the musculoskeletal, cardiovascular and respiratory system. The administration of the cortisone, the immobility, the sepsis and hyperglycemia are included in the risk factors. The prevention is the primary therapeutic agent and this is achieved due to the early mobilization of the patients, the use of neuromuscular electrical stimulation and the avoidance of exposure to risk factors.

Conclusions:

The prevention of muscle atrophy is a primary goal of treatment for the patients in the ICU, because it reduces the incidence of the disease, reduces the time spent in ICU and finally improves the quality of patients’ life.

[Evolution in muscle strength in critical patients with invasive mechanical ventilation]

OBJECTIVE

To assess the evolution of muscle strength in critically ill patients with mechanical ventilation (MV) from withdrawal of sedatives to hospital discharge.

MATERIAL AND METHOD

A cohort study was conducted in two intensive care units in the Hospital Universitari de Bellvitge from November 2011 to March 2012.

INCLUSION CRITERIA

Consecutive patients with MV > 72h. Dependent outcome: Muscle strength measured with the Medical Research Council (MRC) scale beginning on the first day the patient was able to answer 3 out of 5 simple orders (day 1), every week, at ICU discharge and at hospital discharge or at day 60 Independent outcomes: factors associated with muscle strength loss, ventilator-free days, ICU length of stay and hospital length of stay. The patients were distributed into two groups (MRC< 48, MRC ≥ 48) after the first measurement.

RESULTS

Thirty-four patients were assessed. Independent outcomes associated with muscle strength weakness were: days with cardiovascular SOFA >2 (P<.001) and days with costicosteroids (P<.001). Initial MRC in MRC<48 group was 38 (27-43), and 52 (50-54) in MRC ≥ 48. The largest muscle strength gain was obtained the first week (31% versus 52%). A MRC < 48 value was associated with more MV days (P<.007) and a longer ICU stay. (P<.003).

CONCLUSION

The greatest muscle strength gain after withdrawing of the sedatives was achieved in the first week. Muscle strength loss was associated with a cardiovascular SOFA > 2 and costicosteroids. Patients with a MRC < 48 required more days with MV and a longer ICU stay.

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.

Perioperative physiotherapy

PURPOSE OF REVIEW

Physiotherapy in the perioperative period is emerging as an important component of postoperative recovery. This review highlights recent advances in the implementation of physiotherapy in the perioperative period and its enhancement of postsurgical outcomes.

RECENT FINDINGS

Physical therapy in the preoperative period can improve physical deconditioning and potentially affect subsequent postsurgical outcomes. Fast-track surgical programs have highlighted the importance of early ambulation in the postoperative period. Incorporation of this multimodal, evidenced-based approach has been shown to reduce postoperative pulmonary complications and shorten hospital length of stay. Physiotherapy is feasible and well tolerated in patients who remain intubated and mechanically ventilated in the postoperative period. This approach also improves duration of mechanical ventilation and return to functional independence at hospital discharge.

SUMMARY

Timely and early physiotherapy in the perioperative period improves surgical recovery and reduces postoperative complications.

Neuromuscular electrical stimulation for preventing skeletal-muscle weakness and wasting in critically ill patients: a systematic review

BACKGROUND

Neuromuscular electrical stimulation (NMES) therapy may be useful in early musculoskeletal rehabilitation during acute critical illness. The objective of this systematic review was to evaluate the effectiveness of NMES for preventing skeletal-muscle weakness and wasting in critically ill patients, in comparison with usual care.

METHODS

We searched PubMed, CENTRAL, CINAHL, Web of Science, and PEDro to identify randomized controlled trials exploring the effect of NMES in critically ill patients, which had a well-defined NMES protocol, provided outcomes related to skeletal-muscle strength and/or mass, and for which full text was available. Two independent reviewers extracted data on muscle-related outcomes (strength and mass), and participant and intervention characteristics, and assessed the methodological quality of the studies. Owing to the lack of means and standard deviations (SDs) in some studies, as well as the lack of baseline measurements in two studies, it was impossible to conduct a full meta-analysis. When means and SDs were provided, the effect sizes of individual outcomes were calculated, and otherwise, a qualitative analysis was performed.

RESULTS

The search yielded 8 eligible studies involving 172 patients. The methodological quality of the studies was moderate to high. Five studies reported an increase in strength or better preservation of strength with NMES, with one study having a large effect size. Two studies found better preservation of muscle mass with NMES, with small to moderate effect sizes, while no significant benefits were found in two other studies.

CONCLUSIONS

NMES added to usual care proved to be more effective than usual care alone for preventing skeletal-muscle weakness in critically ill patients. However, there is inconclusive evidence for its benefit in prevention of muscle wasting.

ICU-based rehabilitation and its appropriate metrics

PURPOSE OF REVIEW

Survival of critically ill patients is frequently associated with significant functional impairment and reduced health-related quality of life. Early rehabilitation of ICU patients has recently been identified as an important focus for interdisciplinary ICU teams. However, the amount of rehabilitation performed in ICUs is often inadequate. The scope of the review is to discuss recent developments in application of assessment tools and rehabilitation in critically ill patients within an interdisciplinary approach.

RECENT FINDINGS

ICU-based rehabilitation has become an important evidence-based component in the management of patients with critical illness. The assessment and evidence-based treatment of these patients should include a focus on prevention and treatment of deconditioning (muscle weakness, joint stiffness, impaired functional performance) and weaning failure (respiratory muscle weakness) to identify targets for rehabilitation. A variety of modalities for assessment and early ICU rehabilitation are supported by emerging clinical research and must be implemented according to the stage of critical illness, comorbidities, and consciousness and cooperation of the patient.

SUMMARY

Daily evaluation of every critically ill patient should include evaluation of the need for bedrest and immobility, and assessment of the potential for early rehabilitation interventions. Early ICU rehabilitation is an interdisciplinary team responsibility, involving physical therapists, occupational therapists, nurses and medical staff.

Early physical and occupational therapy in mechanically ventilated, critically ill patients: a randomised controlled trial

BACKGROUND

Long-term complications of critical illness include intensive care unit (ICU)-acquired weakness and neuropsychiatric disease. Immobilisation secondary to sedation might potentiate these problems. We assessed the efficacy of combining daily interruption of sedation with physical and occupational therapy on functional outcomes in patients receiving mechanical ventilation in intensive care.

METHODS

Sedated adults (>/=18 years of age) in the ICU who had been on mechanical ventilation for less than 72 h, were expected to continue for at least 24 h, and who met criteria for baseline functional independence were eligible for enrolment in this randomised controlled trial at two university hospitals. We randomly assigned 104 patients by computer-generated, permuted block randomisation to early exercise and mobilisation (physical and occupational therapy) during periods of daily interruption of sedation (intervention; n=49) or to daily interruption of sedation with therapy as ordered by the primary care team (control; n=55). The primary endpoint-the number of patients returning to independent functional status at hospital discharge-was defined as the ability to perform six activities of daily living and the ability to walk independently. Therapists who undertook patient assessments were blinded to treatment assignment. Secondary endpoints included duration of delirium and ventilator-free days during the first 28 days of hospital stay. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00322010.

FINDINGS

All 104 patients were included in the analysis. Return to independent functional status at hospital discharge occurred in 29 (59%) patients in the intervention group compared with 19 (35%) patients in the control group (p=0.02; odds ratio 2.7 [95% CI 1.2-6.1]). Patients in the intervention group had shorter duration of delirium (median 2.0 days, IQR 0.0-6.0 vs 4.0 days, 2.0-8.0; p=0.02), and more ventilator-free days (23.5 days, 7.4-25.6 vs 21.1 days, 0.0-23.8; p=0.05) during the 28-day follow-up period than did controls. There was one serious adverse event in 498 therapy sessions (desaturation less than 80%). Discontinuation of therapy as a result of patient instability occurred in 19 (4%) of all sessions, most commonly for perceived patient-ventilator asynchrony.

INTERPRETATION

A strategy for whole-body rehabilitation-consisting of interruption of sedation and physical and occupational therapy in the earliest days of critical illness-was safe and well tolerated, and resulted in better functional outcomes at hospital discharge, a shorter duration of delirium, and more ventilator-free days compared with standard care.

FUNDING

None.

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

OBJECTIVE

To investigate risk factors of critical illness polyneuromyopathy (CIPM) in a general multidisciplinary intensive care unit (ICU).

PATIENTS AND METHODS

Prospective observational study in a 28-bed university multidisciplinary ICU. Four hundred and seventy-four (323 M/151 F, age 55 +/- 19) consecutive patients were prospectively evaluated. All patients were assigned admission Acute Physiology and Chronic Health Evaluation (APACHE II; 15 +/- 7) and Sequential Organ Failure Assessment (SOFA; 6 +/- 3) scores and were subsequently evaluated for newly developed neuromuscular weakness. Other potential causes of new-onset weakness after ICU admission were excluded before CIPM was diagnosed.

RESULTS

Forty-four (23.8%) of 185 patients developed generalized weakness that met the criteria for CIPM. Patients with CIPM had higher APACHE II (18.9 +/- 6.6 vs 15.6 +/- 6.4, P = 0.004) and SOFA scores (8.4 +/- 2.9 vs 7.1 +/- 2.9, P = 0.013). According to multivariate logistic regression analysis, the following risk factors were independently associated with the development of CIPM: severity of illness at the time of ICU admission, administration of aminoglycoside antibiotics and high blood glucose levels. Analysis according to severity of illness stratification revealed the emergence of Gram (-) bacteremia as the most important independent predisposing factor for CIPM development in less severely ill patients.

CONCLUSIONS

CIPM has a high incidence in the ICU setting. Our study revealed the association of aminoglycosides, hyperglycemia and illness severity with CIPM development, as well as the association between Gram (-) bacteremia and development of CIPM in less severely ill patient population.

Trend of maximal inspiratory pressure in mechanically ventilated patients: predictors

INTRODUCTION

It is known that mechanical ventilation and many of its features may affect the evolution of inspiratory muscle strength during ventilation. However, this evolution has not been described, nor have its predictors been studied. In addition, a probable parallel between inspiratory and limb muscle strength evolution has not been investigated.

OBJECTIVE

To describe the variation over time of maximal inspiratory pressure during mechanical ventilation and its predictors. We also studied the possible relationship between the evolution of maximal inspiratory pressure and limb muscle strength.

METHODS

A prospective observational study was performed in consecutive patients submitted to mechanical ventilation for > 72 hours. The maximal inspiratory pressure trend was evaluated by the linear regression of the daily maximal inspiratory pressure and a logistic regression analysis was used to look for independent maximal inspiratory pressure trend predictors. Limb muscle strength was evaluated using the Medical Research Council score.

RESULTS

One hundred and sixteen patients were studied, forty-four of whom (37.9%) presented a decrease in maximal inspiratory pressure over time. The members of the group in which maximal inspiratory pressure decreased underwent deeper sedation, spent less time in pressure support ventilation and were extubated less frequently. The only independent predictor of the maximal inspiratory pressure trend was the level of sedation (OR=1.55, 95% CI 1.003 - 2.408; p = 0.049). There was no relationship between the maximal inspiratory pressure trend and limb muscle strength.

CONCLUSIONS

Around forty percent of the mechanically ventilated patients had a decreased maximal inspiratory pressure during mechanical ventilation, which was independently associated with deeper levels of sedation. There was no relationship between the evolution of maximal inspiratory pressure and the muscular strength of the limb.

ICU-Acquired Weakness

Observational studies of patients receiving prolonged mechanical ventilation and other forms of critical care support have determined acquired neuromuscular disorders to be extremely common. Early studies used electrophysiologic investigations to diagnose critical illness polyneuropathy (CIP) and muscle biopsy to confirm critical illness myopathy (CIM). More recent approaches seek to obviate these invasive techniques and build on a standardized bedside neuromuscular examination to identify patients with acquired weakness syndromes. Serial examination in the alert patient may serve as a reasonable prognosticator for most patients. The importance of ICU-acquired weakness syndromes is supported by the observation that muscle wasting and weakness are among the most prominent long-term complications of survivors of ARDS. In addition, a strong association appears to exist between acquired weakness and protracted ventilator dependence, an important determinant of ICU length of stay. Multivariate analysis has identified several risk factors associated with increased incidence for ICU-acquired weakness, including severe systemic inflammation, medications (specifically, corticosteroids and neuromuscular blocking agents), glycemic control, and immobility. We advocate an approach to this common syndrome that identifies risk factors early in the hope of minimizing their impact.

New modalities of mechanical ventilation: high-frequency oscillatory ventilation and airway pressure release ventilation

Management of acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS) is largely supportive, with the use of mechanical ventilation being a central feature. Recent advances in the understanding of ALI/ARDS and mechanical ventilation have revealed that lung-protective ventilation strategies may attenuate ventilator-associated lung injury and improve patient morbidity/mortality. High-frequency oscillatory ventilation and airway pressure release ventilation are two novel alternative modes of ventilation that theoretically fulfill the principles of lung protection and may offer an advantage over conventional ventilation for ALI/ARDS.

Brief review: Nondepolarizing neuromuscular blocking drugs and critical illness myopathy

PURPOSE

Critically-ill patients who receive nondepolarizing neuromuscular blocking drugs (NMBDs) may be at risk of developing profound muscle weakness that may last for months after the NMBD is discontinued, especially when large cumulative doses of NMBDs and corticosteroids are co-administered to septic, mechanically ventilated patients. This review focuses on the etiology and clinical features of critical illness myopathy (CIM), summarizes specific risk factors for its development, and discusses strategies that might be used to attenuate or even prevent the development of this potentially devastating syndrome.

CLINICAL FEATURES

The etiology of CIM is unknown. Whether it can develop in at-risk patients who undergo lengthy operations during which they receive NMBDs is also unknown. In some patients following exposure to NMBDs their motor systems are impaired secondary to loss of thick (myosin) filaments that render the muscle unexcitable to direct electrical stimulation, while the sensory system is spared. Management of patients who develop NMBD myopathy is supportive, consisting of nutritional support, physical therapy, and daily trials of decreased ventilatory support.

CONCLUSION

Recent guidelines recommend that NMBDs be used in critically ill patients only when absolutely necessary, that the depth of muscle paralysis be monitored to avoid overdosing and metabolite accumulation, and that drug administration be curtailed periodically to allow interruption of sustained NMBD effect.

Nursing care of the mechanically ventilated patient: what does the evidence say? Part one

The care of the mechanically ventilated patient is at the core of a nurse's clinical practice in the Intensive Care Unit (ICU). Published work relating to the numerous nursing issues of the care of the mechanically ventilated patient in the ICU is growing significantly. Literature focuses on patient assessment and management strategies for patient stressors, pain and sedation. Yet this literature is fragmentary by nature. The purpose of this paper is to provide a single comprehensive examination of the evidence related to the care of the mechanically ventilated patient. In part one of this two-part paper, the evidence on nursing care of the mechanically ventilated patient is explored with specific focus on patient safety: particularly patient and equipment assessment. Part two of the paper examines the evidence related to the mechanically ventilated patient's comfort, the patient/family unit, patient position, hygiene, management of stressors, pain management and sedation.

Effects of physical training on functional status in patients with prolonged mechanical ventilation

BACKGROUND AND PURPOSE

Patients requiring prolonged mechanical ventilation (PMV) are frequently deconditioned because of respiratory failure precipitated by the underlying disease, the adverse effects of medications, and a period of prolonged immobilization. The effects of 6 weeks of physical training on the strength of respiratory and limb muscles, on ventilator-free time, and on functional status in patients requiring PMV were examined.

SUBJECTS

Thirty-nine patients with PMV were initially enrolled in the study and were assigned to either a treatment group (n=20) or a control group (n=19). Three subjects in the treatment group and 4 subjects in the control group died during the 6-week intervention period and thus their data were excluded from the final analysis.

METHODS

Subjects in the treatment group received physical training 5 days a week for 6 weeks. Strength of respiratory and limb muscles, ventilator-free time, and functional status, which was measured by the Barthel Index of Activities of Daily Living (BI) and Functional Independence Measure (FIM), were examined at baseline and at the third and sixth weeks of the study period.

RESULTS

Respiratory and limb muscle strength improved significantly at the third and sixth weeks in the treatment group compared with baseline measurements. Total BI and FIM scores increased significantly in the treatment group and remained unchanged in the control group. Effect sizes of the BI and FIM scores were 2.02 and 1.93, respectively, at the sixth week.

DISCUSSION AND CONCLUSION

The results show that a 6-week physical training program may improve limb muscle strength and ventilator-free time and thus improve functional outcomes in patients requiring PMV.

Weakness in the ICU: Guillain-Barré syndrome, myasthenia gravis, and critical illness polyneuropathy/myopathy

BACKGROUND

Weakness in the ICU may be caused by a number of disorders. Guillain-Barré syndrome (GBS) and myasthenia gravis (MG) are examples of conditions that might lead to an ICU admission. The most likely cause of weakness after ICU admission is critical illness polyneuropathy/myopathy (CIP/M).

REVIEW SUMMARY

Studies have attempted to determine both clinical and pulmonary function criteria for the proper timing of intubation in severe GBS and MG. Optimizing medical management of patients with GBS, MG, and CIP/M is essential in reducing the high morbidity and mortality associated with these conditions. This includes measures to prevent deep venous thrombosis, gastric and decubitus ulcer prophylaxis, and chest physiotherapy. Both intravenous immunoglobulin (IVIG) and therapeutic plasma exchange (TPE) are probably equal in efficacy for the treatment of GBS, although relapse rates may differ. Treatment of MG crisis with TPE or IVIG must be followed by long-term immunosuppression. Studies suggest possible preventative measures for CIP/M such as tighter glycemic control but there are still no definitive treatments.

CONCLUSION

Research to advance our knowledge of the pathogenesis of GBS, MG, and CIP/M is clearly needed to develop more specific and more effective treatments in the future. In the meantime, measures that optimize medical management can be instituted to improve outcomes in patients with these conditions, preferably in a specialized neuroscience ICU setting.

Les anomalies neuromusculaires acquises de reanimation

Critical illness neuromuscular abnormalities (CINMA) are found in 25 percent of ITU patients who recover consciousness and are characterized by a bilateral and symmetric weakness that involves the four limbs but spares the facial muscles. Electrophysiological testing shows an axonal sensory motor polyneuropathy and/or myopathy. The main risk factors of CINMA are prolonged durations of multiple organ failure and mechanical ventilation, use of corticosteroids and hyperglycaemia. CINMA contribute also to increase the duration of mechanical ventilation, this effect being mediated by diaphragm weakness. The median duration of limb weakness is 21 days, although it can exceed several months in some patients. Few preventive measures have been assessed. Whether the benefit of strict blood glucose control in ITU patients recovering from heart surgery on CINMA incidence can be extended to medical ICU patients needs to be determined.