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

Sea Cucumber-Inspired Microneedle Nerve Guidance Conduit for Synergistically Inhibiting Muscle Atrophy and Promoting Nerve Regeneration

Muscle atrophy resulting from peripheral nerve injury (PNI) poses a threat to a patient's mobility and sensitivity. However, an effective method to inhibit muscle atrophy following PNI remains elusive. Drawing inspiration from the sea cucumber, we have integrated microneedles (MNs) and microchannel technology into nerve guidance conduits (NGCs) to develop bionic microneedle NGCs (MNGCs) that emulate the structure and piezoelectric function of sea cucumbers. Morphologically, MNGCs feature an outer surface with outward-pointing needle tips capable of applying electrical stimulation to denervated muscles. Simultaneously, the interior contains microchannels designed to guide the migration of Schwann cells (SCs). Physiologically, the incorporation of conductive reduced graphene oxide and piezoelectric zinc oxide nanoparticles into the polycaprolactone scaffold enhances conductivity and piezoelectric properties, facilitating SCs' migration, myelin regeneration, axon growth, and the restoration of neuromuscular function. These combined effects ultimately lead to the inhibition of muscle atrophy and the restoration of nerve function. Consequently, the concept of the synergistic effect of inhibiting muscle atrophy and promoting nerve regeneration has the capacity to transform the traditional approach to PNI repair and find broad applications in PNI repair.

Using Physiological Markers to Assess Comfort during Neuromuscular Electrical Stimulation Induced Muscle Contraction in a Virtually Guided Environment: Pilot Study for a Path toward Combating ICU-Acquired Weakness

We assessed the feasibility of implementing a virtually guided Neuromuscular Electrical Stimulation (NMES) protocol over the tibialis anterior (TA) muscle while collecting heart rate (HR), Numeric Pain Rating Scale (NPRS), and quality of contraction (QoC) data. We investigated if HR, NPRS, and QoC differ ON and OFF the TA motor point and explored potential relationships between heart rate variability (HRV) and the NPRS. Twelve healthy adults participated in this cross-sectional study. Three NMES trials were delivered ON and OFF the TA motor point. HR, QoC, and NPRS data were collected. There was no significant difference in HRV ON and OFF the motor point (p > 0.05). The NPRS was significantly greater OFF the motor point (p < 0.05). The QoC was significantly different between motor point configurations (p < 0.05). There was no correlation between the NPRS and HRV (p > 0.05, r = -0.129). We recommend non-electrical methods of measuring muscle activity for future studies. The NPRS and QoC can be administered virtually. Time-domain HRV measures could increase the validity of the protocol. The variables should be explored further virtually to enhance the protocol before eventual ICU studies.

Early Mobilization Using a Mobile Patient Lift in the ICU: A Randomized Controlled Trial

OBJECTIVES

To ascertain whether a mobile patient lift facilitates early mobilization in ventilated ICU patients.

DESIGN

A single-center, open-label, randomized controlled trial.

SETTING

An academic ICU in Tokyo.

PATIENTS

Eighty patients were admitted to ICU and expected ventilation for at least 48 hours.

INTERVENTIONS

In the intervention group, in addition to the rehabilitation protocol received by the control group, patients were assisted in sitting, standing, transfers, and walking using the mobile patient lift.

MEASUREMENTS AND MAIN RESULTS

The intervention group predominantly stood faster than the control group (1.0 vs. 3.0 d, p < 0.01). The Intervention group also had significantly higher Functional Status Score-ICU scores at ICU discharge. However, the Medical Research Council score and Barthel index at discharge, length of ICU stay, and number of ventilator-free days did not differ between the two groups.

CONCLUSIONS

The use of mobile patient lifts facilitates the earlier standing of patients on ventilators. This may contribute to patients improved physical function in the ICU.

TRIAL REGISTRATION

The study protocol was registered with the University Hospital Medical Information Network (UMIN) under the registration number UMIN000044965. Registered July 30, 2021.

Effect of neuromuscular electrical stimulation and early physical activity on ICU-acquired weakness in mechanically ventilated patients: A randomized controlled trial

BACKGROUND

Intensive care unit-acquired weakness (ICU-AW) is common in critically ill patients and increases the duration of mechanical ventilation (MV) and weaning time. Early mobilization, range of motion (ROM) exercises, and neuromuscular electrical stimulation (NMES) can prevent ICU-AW by maintaining muscle mass. However, studies highlighting the effects of combining NMES with early physical activity in ICU patients are limited.

AIM

To evaluate the effect of NMES and early physical activity on ICU-AW in mechanically ventilated patients.

STUDY DESIGN

A single-blinded randomized controlled trial was conducted in Alexandria, Egypt. Patients were randomly assigned to one of four groups: NMES, ROM, combined therapy (ROM + NMES), or conventional care (control group). The Medical Research Council (MRC) scale was used to assess the ICU-AW for the study patients over a 7-day period. The duration of the patient's MV and ICU stays were recorded.

RESULTS

Of the 180 patients who were assessed for eligibility, 124 were randomly assigned to one of four groups: 32 patients in ROM exercises, 30 in NMES, 31 in combined therapy (ROM + NMES), and 31 in the control group. On day 7, ROM + NMES and NMES groups showed higher MRC scores than ROM and control groups (50.37 ± 2.34, 49.77 ± 2.19, 44.97 ± 3.61, and 41.10 ± 3.84, respectively). ANOVA test results indicated significant differences (p < .001) across the four groups. ICU-AW occurred in 0% of the ROM + NMES group, 60% of the ROM group, 13% of the NMES group, and 100% of the control group (p < .001). The MV duration (in days) in the ROM + NMES group was shorter (12.80 ± 3.800) than in the ROM, NMES, or control groups (21.80 ± 4.460, 18.73 ± 4.748, and 20.70 ± 3.932, respectively). ICU-LOS was shorter in the ROM + NMES group (17.43 ± 3.17 days) compared with the ROM group (22.53 ± 4.51 days), the NMES group (21.10 ± 5.0 days), and the control group (21.50 ± 4.42 days) with significant differences (p < .001) between the four groups.

CONCLUSION

Daily sessions of NMES and early physical activity were well tolerated, preserved muscle strength, prevented ICU-AW, and decreased the duration of the MV and ICU stay.

RELEVANCE TO CLINICAL PRACTICE

The findings of this study support the use of NMES and early physical exercises by critical care nurses as part of routine care for critically ill patients.

Effects of acute phase intensive electrical muscle stimulation in COVID-19 patients requiring invasive mechanical ventilation: an observational case-control study

We investigated the effects of acute-phase intensive electrical muscle stimulation (EMS) on physical function in COVID-19 patients with respiratory failure requiring invasive mechanical ventilation (IMV) in the intensive care unit (ICU). Consecutive COVID-19 patients requiring IMV admitted to a university hospital ICU between January and April 2022 (EMS therapy group) or between March and September 2021 (age-matched historical control group) were included in this retrospective observational case-control study. EMS was applied to both upper and lower limb muscles for up to 2 weeks in the EMS therapy group. The study population consisted of 16 patients undergoing EMS therapy and 16 age-matched historical controls (median age, 71 years; 81.2% male). The mean period until initiation of EMS therapy after ICU admission was 3.2 ± 1.4 days. The EMS therapy group completed a mean of 6.2 ± 3.7 EMS sessions, and no adverse events occurred. There were no significant differences between the two groups in Medical Research Council sum score (51 vs. 53 points, respectively; P = 0.439) or ICU mobility scale at ICU discharge. Addition of upper and lower limb muscle EMS therapy to an early rehabilitation program did not result in improved physical function at ICU discharge in severe COVID-19 patients.

Changes in temporal muscle dimensions and their clinical impact in out-of-hospital cardiac arrest survivors

Objective

This study investigates temporal muscle atrophy in out-of-hospital cardiac arrest patients post-resuscitation, seeking associations with neurological outcomes and factors associated with atrophy.

Methods

Using data from six Japanese intensive care units, adult patients' post-resuscitation who underwent head computed tomography scans on admission and two to five days post-admission were assessed. Temporal muscle area, thickness, and density were quantified from a single cross-sectional image. Patients were categorized into 'atrophy' or 'no atrophy' groups based on median daily temporal muscle atrophy rates. The primary outcome was changes in temporal muscle dimensions between admission and follow-up two to five days later. Secondary outcomes included assessing the impact of temporal muscle atrophy on 30-day survival, as well as identifying any clinical factors associated with temporal muscle atrophy.

Results

A total of 185 patients were analyzed. Measurements at follow-up revealed significant decreases in temporal muscle area (214 vs. 191 mm2, p < 0.001), thickness (4.9 vs. 4.7 mm, p < 0.001), and density (46 vs. 44 HU, p < 0.001) compared to those at admission. The median daily rate for temporal muscle area atrophy was 2.0% per day. There was no significant association between temporal muscle atrophy and 30-day survival (hazard ratios, 0.71; 95% CI, 0.41-1.23, p = 0.231). Multivariable logistic regression found no clinical factors significantly associated with temporal muscle atrophy.

Conclusions

Temporal muscle atrophy in post-resuscitation patients occurs rapidly at 2.0% per day. However, there was no significant association with 30-day mortality or any identified clinical factors. Further investigation into its long-term functional implications is warranted.

microRNA-181a Promotes Mitochondrial Dysfunction and Inflammatory Reaction in a Rat Model of Intensive Care Unit-Acquired Weakness by Inhibiting IGFBP5 Expression

This study investigated mechanisms by which microRNA (miR)-181a orchestrates mitochondrial dysfunction and inflammation in a rat model of intensive care unit-acquired weakness (ICU-AW). Expression of miR-181a and insulin-like growth factor binding protein 5 (IGFBP5) was detected and then miR-181a was overexpressed or inhibited and IGFBP5 was overexpressed in the ICU-AW rats. The expression of UCP-3, metaphase chromosome protein 1 (MCP1), mitochondrial DNA (mtDNA), inflammatory factors, phosphorylation (p)-JAK1, p-STAT1, and p-STAT2 were measured in skeletal muscle tissues; binding of miR-181a to IGFBP5 was evaluated by a dual-luciferase reporter assay. The results demonstrated high expression of miR-181a and low expression of IGFBP5 in ICU-AW versus control rats; IGFBP5 was identified as a target gene of miR-181a. Further experiments demonstrated that ICU-AW rats suffered from marked loss of grip strength and decreased adenosine triphosphate production, mtDNA content, and UCP-3 mRNA expression in skeletal muscles; this was accompanied by elevated TNF-α, IL-6, IL-1β, MCP1, p-JAK1, p-STAT1, and p-STAT2 levels. Importantly, miR-181a suppression alleviated strength loss, inflammatory reaction, and mitochondrial dysfunction and diminished the phosphorylation levels of JAK1, STAT1, and STAT2 whereas IGFBP5 upregulation rescued the effect of miR-181a overexpression in ICU-AW rats. These results indicate that miR-181a promotes mitochondrial dysfunction and inflammation by activating the JAK/STAT pathway via IGFBP5 in ICU-AW model rats.

A randomized controlled clinical trial of the effects of range of motion exercises and massage on muscle strength in critically ill patients

Background

Atrophy and muscle weakness is a common problem in critically ill patients admitted to the intensive care unit (ICU). Muscle weakness in severe cases can lead to tetraplegia, reduced or lost tendon reflexes, delayed weaning from mechanical ventilation, physical disability, and increased mortality. The aim of this study was to compare the effects of range of motion exercises (ROM) and massage on muscle strength of the patients admitted to ICUs.

Methods

This study was a single-blinded randomized controlled trial conducted in ICUs of Afzalipour hospital in Kerman, southeastern Iran. Ninety conscious ICU patients were randomly divided into three groups (massage, ROM exercises and control). The researcher/co-researcher massaged or did ROM exercises on the patients’ extremities once a day for seven consecutive days. Using a hand-held dynamometer, the co-researcher, rated the muscle strength before, on the fourth and seventh days of intervention at 8 p.m.

Results

The mean muscles strength of the right arm in the ROM exercise and massage groups increased by 0.63 kg, and 0.29 kg, respectively after the intervention compared with before the intervention. The muscle strength of the right arm in the control group reduced by 0.55 kg. The mean muscles strength of the left arm in the ROM exercise and massage groups increased by 0.61 kg and 0.28 kg after the intervention, respectively while it reduced by 0.56 kg in the control group. The mean muscles strength of the right leg in the ROM exercise and massage groups increased by 0.53 kg and 0.27 kg after the intervention compared with before the intervention while it reduced by 0.70 kg in the control group. The mean muscles strength of the left leg in the ROM exercise and massage groups increased by 0.54 kg and 0.26 kg after the intervention compared with before the intervention while it reduced by 0.71 kg in the control group.

Conclusion

The results of the present study showed that ROM exercises and massage were effective interventions in increasing muscle strength of the critically ill patients admitted to intensive care units.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13102-022-00489-z.

Upper Arm Muscular Echogenicity Predicts Intensive Care Unit-acquired Weakness in Critically Ill Patients

Objectives:

Methods:

Results:

Conclusions:

Early Pulmonary Rehabilitation with Neuromuscular Electrical Stimulation in a Patient with Acute Exacerbation of Rheumatoid Arthritis-associated Interstitial Lung Disease: A Case Report

INTRODUCTION

Early implementation of neuromuscular electrical stimulation (NMES) has been reported to prevent muscle atrophy and physical functional decline in patients requiring mechanical ventilation. However, its effect in patients with acute exacerbation of interstitial lung disease (ILD) remains unclear. We herein report our experience using the NMES combined with mobilization in a patient with an acute exacerbation of rheumatoid arthritis-associated ILD (RA-ILD) requiring mechanical ventilation.

CASE PRESENTATION

A 74-year-old man was admitted to the intensive care unit (ICU) and put on mechanical ventilation due to severe acute exacerbation of RA-ILD. Early mobilization and the NMES using a belt electrode skeletal muscle electrical stimulation system were started on day 7 of hospitalization (day 2 of ICU admission). The NMES duration was 20 min, performed once daily. The patient could perform mobility exercises on day 8 and could walk on day 16. We assessed his rectus femoris and quadriceps muscle thicknesses using ultrasound imaging, and found decreases of 4.5% and 8.4%, respectively, by day 14. On day 27, he could independently visit the lavatory, and the NMES was discontinued. He was instructed to start long-term oxygen therapy on day 49 and was discharged on day 63. His 6-minute walk distance was 308 m and his muscle thickness recovered to levels comparable to those at the initial evaluation at the time of discharge.

CONCLUSION

Combining the NMES and mobilization started in the early phase and continued after ICU discharge was safe and effective in a patient with a severe acute exacerbation of RA-ILD.

Rectus Femoris Mimicking Ultrasound Phantom for Muscle Mass Assessment: Design, Research, and Training Application

Ultrasound has become widely used as a means to measure the rectus femoris muscle in the acute and chronic phases of critical illness. Despite its noninvasiveness and accessibility, its accuracy highly depends on the skills of the technician. However, few ultrasound phantoms for the confirmation of its accuracy or to improve technical skills exist. In this study, the authors created a novel phantom model and used it for investigating the accuracy of measurements and for training. Study 1 investigated how various conditions affect ultrasound measurements such as thickness, cross-sectional area, and echogenicity. Study 2 investigated if the phantom can be used for the training of various health care providers in vitro and in vivo. Study 1 showed that thickness, cross-sectional area, and echogenicity were affected by probe compression strength, probe angle, phantom compression, and varying equipment. Study 2 in vitro showed that using the phantom for training improved the accuracy of the measurements taken within the phantom, and Study 2 in vivo showed the phantom training had a short-term effect on improving the measurement accuracy in a human volunteer. The new ultrasound phantom model revealed that various conditions affected ultrasound measurements, and phantom training improved the measurement accuracy.

Effect of Electrical Muscle Stimulation on Upper and Lower Limb Muscles in Critically Ill Patients: A Two-Center Randomized Controlled Trial

OBJECTIVES

Electrical muscle stimulation is widely used to enhance lower limb mobilization. Although upper limb muscle atrophy is common in critically ill patients, electrical muscle stimulation application for the upper limbs has been rarely reported. The purpose of this study was to investigate whether electrical muscle stimulation prevents upper and lower limb muscle atrophy and improves physical function.

DESIGN

Randomized controlled trial.

SETTING

Two-center, mixed medical/surgical ICU.

PATIENTS

Adult patients who were expected to be mechanically ventilated for greater than 48 hours and stay in the ICU for greater than 5 days.

INTERVENTIONS

Forty-two patients were randomly assigned to the electrical muscle stimulation (n = 17) or control group (n = 19).

MEASUREMENTS AND MAIN RESULTS

Primary outcomes were change in muscle thickness and cross-sectional area of the biceps brachii and rectus femoris from day 1 to 5. Secondary outcomes included occurrence of ICU-acquired weakness, ICU mobility scale, length of hospitalization, and amino acid levels. The change in biceps brachii muscle thickness was -1.9% versus -11.2% in the electrical muscle stimulation and control (p = 0.007) groups, and the change in cross-sectional area was -2.7% versus -10.0% (p = 0.03). The change in rectus femoris muscle thickness was -0.9% versus -14.7% (p = 0.003) and cross-sectional area was -1.7% versus -10.4% (p = 0.04). No significant difference was found in ICU-acquired weakness (13% vs 40%; p = 0.20) and ICU mobility scale (3 vs 2; p = 0.42) between the groups. The length of hospitalization was shorter in the electrical muscle stimulation group (23 d [19-34 d] vs 40 d [26-64 d]) (p = 0.04). On day 3, the change in the branched-chain amino acid level was lower in the electrical muscle stimulation group (40.5% vs 71.5%; p = 0.04).

CONCLUSIONS

In critically ill patients, electrical muscle stimulation prevented upper and lower limb muscle atrophy and attenuated proteolysis and decreased the length of hospitalization.

Urinary Titin Is a Novel Biomarker for Muscle Atrophy in Nonsurgical Critically Ill Patients: A Two-Center, Prospective Observational Study

OBJECTIVES

Although skeletal muscle atrophy is common in critically ill patients, biomarkers associated with muscle atrophy have not been identified reliably. Titin is a spring-like protein found in muscles and has become a measurable biomarker for muscle breakdown. We hypothesized that urinary titin is useful for monitoring muscle atrophy in critically ill patients. Therefore, we investigated urinary titin level and its association with muscle atrophy in critically ill patients.

DESIGN

Two-center, prospective observational study.

SETTING

Mixed medical/surgical ICU in Japan.

PATIENTS

Nonsurgical adult patients who were expected to remain in ICU for greater than 5 days.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Urine samples were collected on days 1, 2, 3, 5, and 7 of ICU admission. To assess muscle atrophy, rectus femoris cross-sectional area and diaphragm thickness were measured with ultrasound on days 1, 3, 5, and 7. Secondary outcomes included its relationship with ICU-acquired weakness, ICU Mobility Scale, and ICU mortality. Fifty-six patients and 232 urinary titin measurements were included. Urinary titin (normal range: 1-3 pmol/mg creatinine) was 27.9 (16.8-59.6), 47.6 (23.5-82.4), 46.6 (24.4-97.6), 38.4 (23.6-83.0), and 49.3 (27.4-92.6) pmol/mg creatinine on days 1, 2, 3, 5, and 7, respectively. Cumulative urinary titin level was significantly associated with rectus femoris muscle atrophy on days 3-7 (p ≤ 0.03), although urinary titin level was not associated with change in diaphragm thickness (p = 0.31-0.45). Furthermore, cumulative urinary titin level was associated with occurrence of ICU-acquired weakness (p = 0.01) and ICU mortality (p = 0.02) but not with ICU Mobility Scale (p = 0.18).

CONCLUSIONS

In nonsurgical critically ill patients, urinary titin level increased 10-30 times compared with the normal level. The increased urinary titin level was associated with lower limb muscle atrophy, occurrence of ICU-acquired weakness, and ICU mortality.

Measuring and Monitoring Skeletal Muscle Mass after Stroke: A Review of Current Methods and Clinical Applications

OBJECTIVES

Muscle mass at admission is important to survive stroke, and stroke-induced sarcopenia is a serious problem because of its poor prognosis. Muscle mass measurement and monitoring are essential for appropriate rehabilitation and nutrition management. However, few reviews are available about the muscle mass measurement and monitoring after stroke.

MATERIAL AND METHODS

Several methods are used to assess skeletal muscle mass in stroke, such as computed tomography (CT), ultrasound, bioelectrical impedance analysis, dual-energy X-ray absorptiometry, biomarkers, and anthropometrics. We summarized the current methods and clinical applications in stroke.

RESULTS

In stroke, a head CT is used to estimate muscle mass by measuring the temporal muscle. However, it can be conducted retrospectively due to radiation exposure. After stroke, limb muscle atrophy and diaphragm dysfunction are observed using ultrasound. However, ultrasound requires an understanding of the methods and skill. A bioelectrical impedance analysis can be used to assess muscle mass in patients after a stroke unless they have dynamic fluid changes. Dual-energy X-ray absorptiometry is used for follow-up after hospital discharge. Urinary titin N-fragment and serum C-terminal agrin fragment reflect muscle atrophy after stroke. Anthropometrics may be useful with limited resources.

CONCLUSIONS

We summarized the features of each measurement and proved the recent evidence to properly measure and monitor skeletal muscle mass after stroke.

Effect of vibration therapy on physical function in critically ill adults (VTICIA trial): protocol for a single-blinded randomised controlled trial

INTRODUCTION

Vibration therapy has been used as an additional approach in passive rehabilitation. Recently, it has been demonstrated to be feasible and safe for critically ill patients, whose muscle weakness and intensive care unit (ICU)-acquired weakness are serious problems. However, the effectiveness of vibration therapy in this population is unclear.

METHODS AND ANALYSIS

This study will enrol 188 adult critically ill patients who require further ICU stay after they can achieve sitting at the edge of the bed or wheelchair. The sample size calculation is based on a 15% improvement of Functional Status Score for the ICU. They will be randomised to vibration therapy coupled with protocolised mobilisation or to protocolised mobilisation alone; outcomes will be compared between the two groups. Therapy will be administered using a low-frequency vibration device (5.6-13 Hz) for 15 min/day from when the patient first achieves a sitting position and onward until discharge from the ICU. Outcome assessments will be blinded to the intervention. Primary outcome will be measured using the Functional Status Score for the ICU during discharge. Secondary outcomes will be identified as follows: delirium, Medical Research Council Score, ICU-acquired weakness, the change of biceps brachii and rectus femoris muscle mass measured by ultrasound, ICU mobility scale and ventilator-free and ICU-free days (number of free days during 28 days after admission). For safety assessment, vital signs will be monitored during the intervention.

ETHICS AND DISSEMINATION

This study has been approved by the Clinical Research Ethics Committee of Tokushima University Hospital. Results will be disseminated through publication in a peer-reviewed journal and presented at conferences.

TRIAL REGISTRATION NUMBER

UMIN000039616.

Urinary Titin N-Fragment as a Biomarker of Muscle Atrophy, Intensive Care Unit-Acquired Weakness, and Possible Application for Post-Intensive Care Syndrome

Titin is a giant protein that functions as a molecular spring in sarcomeres. Titin interconnects the contraction of actin-containing thin filaments and myosin-containing thick filaments. Titin breaks down to form urinary titin N-fragments, which are measurable in urine. Urinary titin N-fragment was originally reported to be a useful biomarker in the diagnosis of muscle dystrophy. Recently, the urinary titin N-fragment has been increasingly gaining attention as a novel biomarker of muscle atrophy and intensive care unit-acquired weakness in critically ill patients, in whom titin loss is a possible pathophysiology. Furthermore, several studies have reported that the urinary titin N-fragment also reflected muscle atrophy and weakness in patients with chronic illnesses. It may be used to predict the risk of post-intensive care syndrome or to monitor patients' condition after hospital discharge for better nutritional and rehabilitation management. We provide several tips on the use of this promising biomarker in post-intensive care syndrome.

Elevated Urinary Titin and its Associated Clinical Outcomes after Acute Stroke

INTRODUCTION

Urinary titin is a biomarker of muscle atrophy, which is a serious complication after stroke. However, there are currently no clinical data regarding urinary titin in stroke patients.

METHODS

Consecutive stroke patients admitted to the stroke care unit were included. Spot urine samples were collected immediately after admission, and on days 3, 5, and 7. The primary outcome was the trend of urinary titin in patients after acute stroke. The secondary outcomes included the association between the peak urinary titin level and the modified Rankin Scale (mRS) score, the National Institutes of Health Stroke Scale (NIHSS) score, and the Barthel index (BI) upon hospital discharge. Multivariate analysis was adjusted for age, sex, NIHSS at admission, and the peak urinary titin to predict poor outcome (mRS 3-6).

RESULTS

Forty-one patients were included (29 male; age, 68 ± 15 years), 29 had ischemic stroke, 8 had intracerebral hemorrhage, and 4 had subarachnoid hemorrhage. The levels of urinary titin on days 1, 3, 5, and 7 were 9.9 (4.7-21.1), 16.2 (8.6-22.0), 8.9 (4.8-15.2), and 8.7 (3.6-16.2) pmol/mg Cr, respectively. The peak urinary titin level was associated with the mRS score (r = 0.55, p < 0.01), the NIHSS score (r = 0.72, p < 0.01), and the BI (r = -0.59, p < 0.01) upon hospital discharge. In multivariate analysis, the peak urinary titin was associated with poor outcome (p = 0.03).

CONCLUSIONS

Urinary titin rapidly increased after stroke and was associated with impaired functional outcomes at hospital discharge.

Upper limb muscle atrophy associated with in-hospital mortality and physical function impairments in mechanically ventilated critically ill adults: a two-center prospective observational study

Background

Lower limb muscle atrophy is often observed in critically ill patients. Although upper limb muscles can undergo atrophy, it remains unclear how this atrophy is associated with clinical outcomes. We hypothesized that this atrophy is associated with mortality and impairments in physical function.

Methods

In this two-center prospective observational study, we included adult patients who were expected to require mechanical ventilation for > 48 h and remain in the intensive care unit (ICU) for > 5 days. We used ultrasound to evaluate the cross-sectional area of the biceps brachii on days 1, 3, 5, and 7 and upon ICU discharge along with assessment of physical functions. The primary outcome was the relationship between muscle atrophy ratio and in-hospital mortality on each measurement day, which was assessed using multivariate analysis. The secondary outcomes were the relationships between upper limb muscle atrophy and Medical Research Council (MRC) score, handgrip strength, ICU Mobility Scale (IMS) score, and Functional Status Score for the ICU (FSS-ICU).

Results

Sixty-four patients (43 males; aged 70 ± 13 years) were enrolled. The Acute Physiology and Chronic Health Evaluation (APACHE) II score was 27 (22–30), and in-hospital mortality occurred in 21 (33%) patients. The decreased cross-sectional area of the biceps brachii was not associated with in-hospital mortality on day 3 (p = 0.43) but was associated on days 5 (p = 0.01) and 7 (p < 0.01), which was confirmed after adjusting for sex, age, and APACHE II score. In 27 patients in whom physical functions were assessed, the decrease of the cross-sectional area of the biceps brachii was associated with MRC score (r = 0.47, p = 0.01), handgrip strength (r = 0.50, p = 0.01), and FSS-ICU (r = 0.56, p < 0.01), but not with IMS score (r = 0.35, p = 0.07) upon ICU discharge.

Conclusions

Upper limb muscle atrophy was associated with in-hospital mortality and physical function impairments; thus, it is prudent to monitor it. (321 words)

Trial registration

UMIN 000031316. Retrospectively registered on 15 February 2018.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40560-020-00507-7.

Early Initiation of Awake Veno-Venous Extracorporeal Membrane Oxygenation Can Attenuate Muscle Atrophy and Weakness in Acute Respiratory Distress Syndrome

Patients with acute respiratory distress syndrome (ARDS) exhibit prominent muscle atrophy and weakness. Although these patients often require deep sedation to perform lung-protective ventilation, extracorporeal membrane oxygenation (ECMO) can keep patients awake and make mobilization possible. A 60-year-old man was treated with ECMO due to ARDS. A multidisciplinary team conducted mobilization with standing on day 3. During intensive care unit (ICU) stay, catabolism was ongoing (urinary titin: 24.1-38.4 pmol/mg Cr), but the rectus femoris muscle, measured by ultrasound, moderately decreased by 5.3%, 10.8%, and 13.0% on days 3, 5, and 7, respectively, with maintained Medical Research Council score of 58-60. Diaphragm thickness remained unchanged. On day 5, he was separated from ECMO. After ambulation training, he was discharged from ICU on day 7. He returned home without prominent physical dysfunction. Our experience indicates early initiation of awake ECMO can accompany mobilization and attenuate muscle atrophy and weakness in ARDS.