1198

Abstract

Introduction: ICU acquired weakness (ICUAW) is defined as a presence of muscle wasting and neuromuscular dysfunction in critically ill patients without plausible etiology. ICUAW is associated with increased mortality, prolonged mechanical ventilation, and impaired post ICU independent life. Bioelectrical impedance analysis (BIA) is an easy, noninvasive method of estimating body composition using different electrical impedance of tissue components. We have attempted to investigate correlation between serial BIA tests and muscle power examinations in the ICUAW case. A 39-year old patient with a history of acute myeloid leukemia on a remission state after chemotherapy and allogeneic peripheral blood stem cell transplantation, was admitted with general weakness and immobilization due to thoracic spine compression fracture. Respiratory failure with hypoxemia and hypercapnia was developed due to hospital acquired pneumonia on the right lower lobe and recurrent left pneumothorax. He was transferred to medical ICU and mechanical ventilator was applied. Chest tube was inserted and intravenous antibiotics were administered. After proper management for 2 weeks, He was recovered from pneumonia and pneumothorax, but muscle power became weakened and atrophy progressed during the ICU stay. He was not able to sit on a bed for himself. Weaning from mechanical ventilator had failed, tracheostomy was done and BIPAP was applied instead. Muscle power grades of all extremities at ICU admission were IV. At 9th day of ICU stay, the motor power of shoulder abduction, adduction of right and left was IV/IV-, IV/IV-, elbow flexion and extension IV-/IV-, IV/IV, wrist flexion and extension, hand grip were all IV on medical research council (MRC) scale. The motor power of hip flexion, extension was III/IV-, III/IV, Knee flexion, extension IV-/ IV-, IV/ IV, ankle dorsiflexion, plantar flexion III/IV, III/IV. Considering the weakness was developed after the onset of pneumonia, generalized involving both proximal and distal muscles, MRC sum score below 48, and dependency on mechanical ventilation, the diagnosis was compatible with ICUAW. The BIA results of skeletal muscle mass (SMM) and Fat free mass (FFM, listed in brackets) was 16kg (32.1kg) at 3rd day of ICU stay, continuous declined to 14.6kg (30.1kg) at 9th day of ICU stay. Appendicular muscle mass of right arm, left arm, right leg and left leg at 3rd day after ICU admission were 0.8, 0.9, 6.2, 6.5kg each. After 9th day of ICU admission, both lower extremities muscle mass decreased from to 6.2kg to 5.0kg at right side and 6.5kg to 5.2kg at left side. Passive range of motion of each joint was maintained during the ICU stay to prevent joint contracture. Physical therapy including range of motion against resistance (RROM) with cycle ergometer and sitting to chair exercise was started at 22th day after ICU admission. After two weeks of physical therapy, the muscle strength of extremities was slightly improved before physical therapy from grade IV- to IV+ in both shoulder adduction and abduction, IV-to IV in right elbow flexion and hip extension, IV to IV+ in right wrist flexion, III to IV- in both ankle dorsiflexion compared with the result of muscle power examination at 9th day. Total SMM and FFM slightly increased from 14.6 to 15.0 and 30.1 to 30.7kg. Appendicular muscle mass of right arm, left arm, right leg and left leg increased from 1.0, 0.9, 5.0, 5.2 to 1.2, 1.0, 5.6, 5.5kg. The change of truncal muscle mass was not correlated with that of partial pressure of arterial CO2 or ventilatory parameters. As a medical condition of the patient was fluctuating, the clinical muscle power after a month was not improved and so was the BIA result. The changes of total skeletal and appendicular muscle mass were proportional to the clinically detected muscle strength. Based on the result, further study is planned to determine whether the BIA could predict occurence and clinical course of ICUAW using variable BIA parameters.