Electrical Stimulation in Patients With Prolonged Mechanical Ventilation

Effects of Muscular Electrical Stimulation on Skeletal and Lung Mechanics in Patients With Prolonged Mechanical Ventilation

Muscle atrophy and diaphragm dysfunction are common complication in patients with prolong mechanical ventilator (PMV) and is associated with increased rate of weaning failure and days of hospitalization. Electrical stimulation (ES) has been shown to be beneficial in patients with severe chronic heart failure and chronic obstructive pulmonary disease. The purpose of this study is to examine the effects of ES on skeletal muscle function, pulmonary mechanics and hospitalization outcomes in patients with PMV.

BACKGROUND AND PURPOSE: Muscle atrophy and diaphragm dysfunction are common complication in patients with prolong mechanical ventilator (PMV) and is associated with increased rate of weaning failure and days of hospitalization. Electrical stimulation (ES) has been shown to be beneficial in patients with severe chronic heart failure and chronic obstructive pulmonary disease. The purpose of this study is to examine the effects of ES on skeletal muscle function, pulmonary mechanics and hospitalization outcomes in patients with PMV.

METHODS: Patients who have been on mechanical ventilator for more than 21 days will be recruited from respiratory care center (RCC). All subjects will be randomly assigned into three groups: ES in abdominal muscles (ES-Abd, n=30),ES in brachial biceps (ES-bicep, n=30) and sham group(Sham). Subjects in both groups will receive ES in muscles for 30 min/session, 2 sessions/day for 10 days with the same setting except area of ES. The muscle function will be assessed by skin-fold thickness and muscle strength. The pulmonary function will be assessed by: lung compliance, airway resistance, tidal volume, minute volume and maximal inspiratory pressure. The hospitalization outcome will be followed up until patients are discharged from RCC. The outcomes variables include: weaning rate and duration, mortality, days of ventilator, and length of RCC stay.

Inclusion Criteria:

• age>20 years old
• mechanical ventilation for more than 6 h/ day for more than 21 days -- medical stability (arterial blood gas value hydrogen power(pH): 7.35-7.45, atrial oxygen pressure(PaO2): 60 mmHg at 40% fraction of inspired oxygen inspired oxygen fraction (FiO2), absence of signs and symptoms of infection, and hemodynamic stability);

Exclusion Criteria:

• signs of acute infection (BT>38.5℃，WBC>12000 or <3000 per unit
• neuromuscular disease at acute stage
• diagnosis of cancer at end-stage
• pregnancy
• BMI>35kg/m2