Electrical Stimulation in Patients With Prolonged Mechanical Ventilation

Not Applicable

Completed

Interventions: Other: sham group
Other: electrical stimulation (high frequency)
Other: electrical stimulation (low frequency)

Brief Summary: 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.

Detailed Description: 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.

Recruitment & Eligibility

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

Arm && Interventions

Group	Intervention	Description
sham group	sham group	Participants will receive similar electrical stimulation (ES) procedure as those in intervention group but with ES machine power off.
electrical stimulation	electrical stimulation (low frequency)	Participants will receive muscular electrical stimulation on quadriceps muscle for 20 min/session, twice daily for 10 days
electrical stimulation	electrical stimulation (high frequency)	Participants will receive muscular electrical stimulation on quadriceps muscle for 20 min/session, twice daily for 10 days

Primary Outcome Measures

Name	Time	Method
Pulmonary Function	end of intervention	The pulmonary function as assessed by the measurement of tidal volume.
Level of Activity of Daily Life	end of intervention	The level of activity of daily life was measured by Functional Independence Measure (FIM) score. Possible scores range from 18 (total assist) to 126 (complete independence).
Muscle Strength	end of intervention	The muscle strength of quadriceps were assessed by Medical Research Council (MRC) scoring system. The MRC score ranges from a 0 points (zero strength) to 5 points (good). The higher points indicated the better muscle strength.