Progressive Mobility in the ICU: Benefits, Barriers, and Best Practices

Background and Origin of Progressive Mobility

Progressive mobility refers to a series of planned and sequential movements aimed at bringing the patient back to his or her baseline (Vollman, 2010). It consists of positioning and mobility techniques. A meta-analysis of 39 randomized trials was conducted to examine the effect of bed rest on 15 different medical conditions and procedures. Four short-term medical conditions were identified for critically ill patients. However, the major and long-term complication was the reduced quality of life after discharge, on account of lost physical functions during the patient's stay in the ICU. Another study conducted among survivors of acute respiratory conditions found that they lost 18% of their body weight and suffered significant functional limitations from muscle wasting and fatigue. The more than 5 million patients who are confined to the ICU each year must contend with both the short- and long-term complications of immobility or prolonged bed rest, which significantly affect morbidity, mortality, healthcare costs, and overall quality of life (Vollman).

The traditional belief was that ICU patients should remain in bed to conserve energy for recovery (Kleinpell, 2011). Before long, however, its adverse effects became well known. Muscle strength decreases by 1–1.5% per day, or up to 20–30% in a week to nine days of bed rest. At five weeks, muscle strength can deplete by 50%, yet a single contraction per day at 50% of maximal strength can prevent this decrease. The decline is greatest in the quadriceps and extensors. The consequent lack of gravitational force and reduced muscular pull on the bones leads to osteopenia, which in turn causes hypercalcemia. Calcium is expelled by the body two to three days after immobilization, and elevated calcium levels persist for three to five or six weeks. The excretion of calcium and phosphorus leads to atrophy and reduces the bone's threshold for fracture.

Adverse Effects of Traditional Bed Rest

Immobility or bed rest also decreases gastrointestinal motility, frequently leading to constipation and loss of appetite. Because of the loss of muscle strength, diaphragm movement and chest expansion also decrease, impairing secretion clearance. Immobility further reduces efficient cardiovascular function and stroke volume while increasing heart rate. The skin likewise atrophies, and pressure sores develop (Strax et al.). In response to these observations, early mobility of critically ill ICU patients has been established as the new standard of care (Kleinpell).

Progressive mobility advances the patient's level of mobility according to a planned sequence (Kleinpell, 2011). It begins with turning exercises and active or passive range-of-motion exercises, followed by dangling, chair positioning, and ambulation. A growing body of research has found that early and progressive mobilization of critically ill ICU patients is feasible, safe, and beneficial in improving or restoring physical functioning in a timely manner. It is also intended to produce secondary benefits, such as reducing heavy sedation, which otherwise limits or prevents patient activity (Kleinpell).

A review of 15 scientific studies drawn from electronic databases covering 2000–2011 — including PubMed, CINAHL, Medline, and The Cochrane Library — found only a limited number of studies that evaluated the topic (Adler & Malone, 2012). The few that did, however, reported on the safety and effectiveness of early mobilization as an intervention capable of producing significant positive outcomes for patient functioning. These included randomized controlled trials involving a limited sample of 171 patients. Their findings identified early physical therapy and ICU mobilization as feasible and safe interventions. The level of improvement in quality of life and muscle strength could not be fully determined at the time due to limited research (Adler & Malone).

Feasibility, Safety, and Benefits of Early Mobilization

Additional studies examined patient outcomes from exercise for ICU patients. Some demonstrated that moderate exercise was useful in controlling inflammation caused by immobility and in increasing muscle strength and overall physical function (Truong et al., 2009). More recent studies confirmed the safety and feasibility of early mobility in the ICU and its potential to reduce even short-term physical impairments. Immobility promotes inflammatory mechanisms and atrophy of skeletal muscle from disuse. Early mobility has been shown to be both feasible and effective in improving clinical outcomes. Ongoing pre-clinical and clinical research on ICU-acquired weakness holds promise for improving the physical function and quality of life of patients who survive critical illness (Truong et al.).

ICU-acquired weakness resulting from critical illness often leads to severe functional impairment and frequently necessitates mechanical ventilation for extended durations (Kress, 2009). Patients typically require frequent sedative medications during these procedures. Recent research has suggested the feasibility and potential advantage of mobilizing these patients while still in the ICU. The intervention requires an entire multidisciplinary team, consisting of a nurse, a physical therapist, an occupational therapist, and a respiratory therapist. Recent investigations have reported on the safety and positive outcomes of the intervention, particularly among the most critically ill. Among these outcomes are a greater number of patients who are able to move around the ICU and the hospital, as well as shortened hospital stays. Preliminary studies support the feasibility and efficacy of the intervention (Kress).

Exercise programs have demonstrated a significant effect on the physical and psychological well-being of ICU patients (Bakers & Malone, 2008). Although overall evidence remains limited, substantial support exists for their value in cardiac and pulmonary patients. A randomized clinical trial evaluated the impact of a six-week rehabilitation program on the physical and psychological recovery of ICU patients. Participants received a self-help rehabilitation manual supplemented with weekly telephone contact. The program produced significantly better physical function outcomes and supported the value of physical rehabilitation following intensive care (Bakers & Malone).

Hospitals aim to reduce both hospital stays and readmissions (Morris et al., 2011). Readmission of acute respiratory failure patients within 12 months after discharge has been a particular concern, as a cohort study linked this population's condition to readmission or death within that period. The 280 study participants were survivors who required subsequent hospitalization and who had taken part in an early ICU mobility program. The study found that 132 patients — 47% of respondents — were readmitted or died within a year of discharge. These individuals were more likely to be female, to have undergone tracheostomy, to have a higher Charlson Comorbidity Index, and to have not participated in the early ICU mobility program. The study concluded that survivors of respiratory failure requiring mechanical ventilation are at high risk for readmission and mortality within the following year. Of the four factors associated with readmission or death, only ICU mobility therapy is modifiable to suit individual patient conditions or preferences (Morris et al.).