Elderly patients who experience a prolonged ICU stay are at high risk for developing post intensive care unit syndrome (PICS), a serious medical condition manifested by loss of muscle mass, weakness, malnutrition and neurocognitive decline. PICS often leads to chronic disability, prolonged mechanical ventilation and the need for costly extended stays in long term care facilities (LTCs). The investigators' preliminary study shows attempts at rehabilitating patients who have already developed PICS are minimally effective, resulting in only modest improvements in functionality. This project will determine the effects of mobility-based physical rehabilitation (MPR) combined with neuromuscular electric stimulation (NMES) and high protein supplementation (HPRO) early in a patients ICU stay on preventing PICS related musculoskeletal and functional deficits, and improving clinical outcomes.

Older, critically ill patients who survive their ICU stay frequently develop post-ICU syndrome (PICS) - a condition manifested by sarcopenia, weakness, malnutrition and neurocognitive decline - which occurs as a result of a critical illness, prolonged bed rest, catabolism, and polypharmacy. PICS frequently leads to chronic disability, prolonged mechanical ventilation (MV), functional deficits, and the need for extended rehabilitation in long term care facilities (LTCs). As the majority of patients admitted to ICUs are ≥ 65 years old, many of these patients are at high risk for PICS. Since the care of ICU patients is primarily focused on the medical management of the acute critical illness, there are limited resources and strategies available to prevent PICS. Evidence suggests mobility-based physical rehabilitation (MPR) combined with resistive training with neuromuscular electric stimulation (NMES) and high protein diets (HPRO) containing essential amino acids can mitigate the loss of muscle mass and function during bed rest in the elderly. The investigators hypothesize that preventive therapy involving the addition of both NMES and HPRO to MPR early and throughout the ICU and hospital stay can mitigate PICS-associated sarcopenia, malnutrition, and immobility to confer valuable health benefits toward recovery. To test this, the investigators will use a 2x2 factorial design in which older, MV ICU patients will all receive comprehensive ICU care and MPR, then be randomized to one of 4 groups: 1) MPR+NMES, 2) MPR+HPRO, 3) all 3 together, or 4) MPR alone (control), to determine independent and combined effects of the interventions.

The Specific Aims are to 1) determine the effects of adding NMES and HPRO interventions to MPR on muscle mass, strength, and mobility function in older, critically ill MV patients while still in the ICU, and 2) determine the effects of adding NMES and HPRO interventions to MPR on the clinical outcomes of time to weaning from MV, ICU/hospital length of stay and discharge disposition of these patients.

This proposal capitalizes on the interdisciplinary collaboration among Pulmonary/Critical Care Intensivists, Physical Therapists, Geriatricians, Clinical Nutritionists, Statisticians and Nutrition and Metabolism clinical researchers examining the efficacy of the proposed comprehensive rehabilitation approach. The investigators' primary goal is to attenuate the severity of sarcopenia and functional decline in this older, critically ill population at risk for severe disability. Additionally, by focusing on maintaining skeletal muscle mass, function, and strength, the investigators hope to improve clinical outcomes. The investigators posit this combined therapy will mitigate PICS-associated disability and speed the recovery from critical illness in older, MV ICU patients. This project has high overall impact as the intervention is easily administered by hospital staff and may greatly reduce the physiological and functional declines while hastening recovery during acute ICU hospitalization in older adults.

Inclusion Criteria:

• Age ≥ 45 years
• Respiratory insufficiency requiring mechanical ventilation (MV)
• ICU presentation < 6 days
• Patient or legally authorized representative able to provide written or witnessed verbal informed consent in English
• All four limbs intact and mobile
• Eligible for and able to participate in physical therapy
• Pre admission Barthel Index >70

Exclusion Criteria:

• Acute kidney injury with a glomerular filtration rate < 30 ml/min
• Diagnosis of severe organ dysfunction including end stage liver disease or cirrhosis
• Diagnosis of active cancer
• Acute or chronic organ transplant rejection
• Exceedingly high mechanical ventilator settings (FiO2>60%, PEEP>12) or alternative modes of mechanical ventilation (inverse ratio pressure control, airway pressure release ventilation)
• Severe functional impairment or physical impairment to rehabilitation
• On high dose vasopressor agents (> 5mcg of norepinephrine or equivalent)
• Liver function tests > 2.5 x normal limits (normal reference ranges include AST between 10 and 40 units/L or ALT between 7 and 56 units/L)
• Chronic dementia or cognitive impairment