Assessment of Limb Muscle Strength in Critically Ill Patients: A Systematic Review

OBJECTIVES To determine the reliability of volitional and nonvolitional limb muscle strength assessment in critically ill patients and to provide guidelines for the implementation of limb muscle strength assessment this population. DATA SOURCES The following computerized bibliographic databases were searched with MeSH terms and keywords or combinations: MEDLINE through PubMed and Embase through Embase.com. STUDY SELECTION Articles were screened by two independent reviewers. Included studies were all performed in humans and were original articles. The research population exists of adult, critically ill patients or ICU survivors of either sex, and those admitted to a medical, surgical, respiratory, or mixed ICU. A study was included if reliability of muscle strength measurements was determined in this population. DATA EXTRACTION Data on baseline characteristics (country, study population, eligibility, age, setting and method, and equipment of limb muscle strength assessment) and reliability scores were obtained by two independent reviewers. DATA SYNTHESIS Data of six observational studies were analyzed. Interrater reliability of the Medical Research Council scale for individual muscle groups varied from "fair" or "substantial" (weighted κ, 0.23-0.64) to "very good" agreement (weighted κ, 0.80-0.96). Interrater reliability of the Medical Research Council-sum score was found to be very good in all four studies (intraclass correlation coefficients, 0.86-0.99 or Pearson product moment correlation coefficient = 0.96). Interrater reliability of handheld dynamometry was comparable between two studies (intraclass correlation coefficients, 0.62-0.96). Interrater reliability of handgrip dynamometry was very good in two studies (intraclass correlation coefficients, 0.89-0.97). Intrarater reliability of handheld dynamometry and handgrip dynamometry was assessed in one study, and results were very good (intraclass correlation coefficients > 0.81). No studies were obtained on reliability of nonvolitional muscle strength assessment. CONCLUSIONS Voluntary muscle strength measurement has proven reliable in critically ill patients provided that strict guidelines on adequacy and standardized test procedures and positions are followed.status: publishe

Physiotherapy in the intensive care unit

Physiotherapists are involved in the management of patients with critical illness. Physiotherapy assessment is focused on physical deconditioning and related problems (muscle weakness, joint stiffness, impaired functional exercise capacity, physical inactivity) and respiratory conditions (retained airway secretions, atelectasis and respiratory muscle weakness) to identify targets for physiotherapy. Evidence-based targets for physiotherapy are deconditioning, impaired airway clearance, atelectasis, (re-)intubation avoidance and weaning failure. Early physical activity and mobilisation are essential in the prevention, attenuation or reversion of physical deconditioning related to critical illness. A variety of modalities for exercise training and early mobility are evidence-based and must be implemented depending on the stage of critical illness, co-morbid conditions and cooperation of the patient. The physiotherapist should be responsible for implementing mobilization plans and exercise prescription and make recommendations for progression of these plans, jointly with medical and nursing staff.status: publishe

The interobserver agreement of handheld dynamometry for muscle strength assessment in critically ill patients

OBJECTIVE:: Muscle weakness often complicates critical illness and is associated with increased risk of morbidity, mortality, and limiting functional outcome even years later. To assess the presence of muscle weakness and to examine the effects of interventions, objective and reliable muscle strength measurements are required. The first objective of this study is to determine interobserver reliability of handheld dynamometry. Secondary objectives are to quantify muscle weakness, to evaluate distribution of muscle weakness, and to evaluate gender-related differences in muscle strength. DESIGN:: Cross-sectional observational study. SETTING:: The surgical and medical intensive care units of a large, tertiary referral, university hospital. PATIENTS:: A cross-sectional, randomly selected sample of awake and cooperative critically ill patients. INTERVENTIONS:: None. MEASUREMENTS AND MAIN RESULTS:: Handheld dynamometry was performed in critically ill patients who had at least a score of 3 (movement against gravity) on the Medical Research Council scale. Three upper limb and three lower limb muscle groups were tested at the right-hand side. Patients were tested twice daily by two independent raters. Fifty-one test-retests were performed in 39 critically ill patients. Handheld dynamometry demonstrated good interobserver agreement with intraclass correlation coefficients >0.90 in four of the muscle groups tested (range, 0.91-0.96) and somewhat less for hip flexion (intraclass correlation coefficient, 0.80) and ankle dorsiflexion (intraclass correlation coefficient, 0.76). Limb muscle strength was considerably reduced in all muscle groups as shown by the median z-score (range, -1.08 to -3.48 sd units). Elbow flexors, knee extensors, and ankle dorsiflexors were the most affected muscle groups. Loss of muscle strength was comparable between men and women. CONCLUSIONS:: Handheld dynamometry is a tool with a very good interobserver reliability to assess limb muscle strength in awake and cooperative critically ill patients. Future studies should focus on the sensitivity of handheld dynamometry in longitudinal studies to evaluate predictive values toward patients' functional outcome.status: publishe

Interobserver agreement of medical research council sum-score and handgrip strength in the intensive care unit

Introduction: Muscle weakness often complicates critical illness and is associated with devastating short- and long-term consequences. For interventional studies, reliable measurements of muscle force in the intensive care unit (ICU) are needed. Methods: To examine interobserver agreement, two observers independently measured Medical Research Council (MRC) sum-score (n = 75) and handgrip strength (n = 46) in a cross-sectional ICU sample. Results: The intraclass correlation coefficient (ICC) for MRC sum-score was 0.95 (0.92-0.97). The kappa coefficient for identifying "significant weakness" (MRC sum-score <48, MRC subtotal upper limbs <24) and "severe weakness" (MRC sum-score <36) was 0.68 ± 0.09, 0.88 ± 0.07, and 0.93 ± 0.07, respectively. The ICC for left and right handgrip strength was 0.97 (0.94-0.98) and 0.93 (0.86-0.97), respectively. Conclusions: Interobserver agreement on MRC sum-score and handgrip strength in the ICU was very good. Agreement on "severe weakness" (MRC sum-score <36) was excellent and supports its use in interventional studies. Agreement on "significant weakness" (MRC sum-score <48) was good, but even better using the equivalent cut-off in the upper limbs. It remains to be determined whether this may serve as a substitute. Muscle Nerve 45: 18-25, 2012.status: publishe