E-Vent: Electrical muscle stimulation in mechanical Ventilation

INTERVENTION: Electrical muscle stimulation twice daily 30 minute sessions of electrical muscle stimulation to biceps and quadriceps, for duration of critical care stay. CONDITION: Critically ill patients receiving prolonged periods of mechanical ventilation ; Respiratory ; Critically ill patients receiving prolonged periods of mechanical ventilation PRIMARY OUTCOME: Ultrasound quadriceps muscle layer thickness; Timepoint(s): Baseline, study days 4,7 and every 3 days, ICU discharge, hospital discharge SECONDARY OUTCOME: 1. US (composite score: mid thigh, forearm and upper arm; rectus femoris cross sectional area ); 2. Manual muscle Testing individual and composite muscle strength scores; 3. Handgrip strength; 4. Hand held dynamometry limb muscle strength; 5. Barthel Index (BI) physical function score; 6. Six‐minute walk test; 7. SF‐36 (v2) health related quality of life questionnaire; 8. Surrogate muscle biomarkers (serum c‐reactive protein (CRP), plasma creatine kinase (PCK), plasma 3 methyl histidine (P3‐MH), urinary creatine kinase (UCK) and 3 methyl histidine (U3‐ MH); 9. MV days; 10. ICU, hospital and 90 day mortality; 11. ICU and hospital length of stay (LOS); 12. Hospital resource use at discharge INCLUSION CRITERIA: 1. The target population is critically ill patients expected to receive prolonged mechanical ventilation (MV) 2. 18 years or older, male and female 3. Expected to receive MV for > 72 hour