Mobilization

Advances in medical technologies have enhanced our ability to prevent, detect, and manage postoperative complications. However, approaches that optimize the body’s own ability to recover are equally important. Wound care, nutrition, mobilization, and the patient’s participation in their own recovery should not be overlooked. In this section, we focus on mobilization (i.e., physical activity or mobility), defined as any bodily movement produced by skeletal muscles that results in energy expenditure.

The topics in this review are organized as follows:

• History of Postoperative Mobilization

• Physiologic Effects of Immobilization

• Benefits of Mobilization

• Implementation of Mobilization Interventions

Other topics related to mobilization are covered in the following rotation guides:

• Sedation and ICU Delirium, Resuscitation Fluids, Shock and Sepsis (Critical Care)

• Venous Thromboembolism (Hematology)

• Frailty, Delirium (Geriatrics)

History of Postoperative Mobilization

The importance of postoperative mobilization was not always appreciated. Throughout the 19th and early 20th centuries, surgeons usually prescribed bed rest for weeks following surgery, based on the notion that immobilization minimized pain and promoted healing by reducing metabolic demands. Early postoperative mobilization was not widely utilized in the United States until World War II, when by necessity, the number of injured soldiers spurred demands to hasten patients’ recovery out of the hospital.

Subsequently, published studies demonstrated that bed rest was not associated with improvement in surgical outcomes and actually increased rates of complications (e.g., deep-vein thromboses, pressure injuries, and pneumonia). Another stimulus for early postoperative mobilization was the development of Diagnosis Related Groups by Medicare in the late 1970s and early 1980s, in which reimbursement was based on diagnosis and incentivized reduced hospital resource utilization. In recent decades, an abundance of evidence has demonstrated that early mobilization is safe, results in improved patient outcomes, and reduces length of hospital stay.

Mobilization, especially after surgery, is a simple yet effective intervention with benefits to patients and the health care system by reducing complications, length of stay, and utilization of other resources. Although the data regarding mobilization in isolation may be absent or mixed in some circumstances, the overall simplicity of implementation, relative low risk, and potential for benefit underscore the importance in postoperative recovery. Patient engagement is critical, and efforts should be made to ensure understanding and motivation.

Physiologic Effects of Immobilization

Both surgery and immobilization have adverse physiologic effects on numerous body systems. Even worse, these two states create a vicious cycle: Surgery often leads to immobility, and immobility exacerbates the consequences of surgery. Immobility is associated with the following physiologic consequences:

• Muscular and cardiovascular deconditioning: Both prolonged immobility and the stress response to surgery or critical illness drive the body into a catabolic state, leading to muscular and cardiovascular deconditioning.

  • These effects extend well beyond hospitalization and can significantly reduce community mobility and participation.

• Venous thromboembolism (VTE): Immobility results in both venous stasis and systemic inflammation, which are risk factors for deep-vein thrombosis (DVT) and pulmonary emboli.

  • The postoperative proinflammatory state or underlying surgical illness (e.g., trauma, cancer) may also increase VTE risk by affecting endothelial function and leading to hypercoagulablity.

• Pulmonary complications: Supine positioning in bed as well as shallow breathing due to postsurgical pain result in a decreased functional residual capacity and contribute to the development of atelectasis.

• Delirium: Bed rest may contribute to disruption of the sleep-wake cycle, which is implicated in the development of delirium.

• Ileus: Delayed return of bowel function, also known as postoperative ileus, is a common complication resulting from surgery, particularly gastronintestinal (GI) surgery, with implications for prolonged hospital stay and development of other complications.

• Insulin resistance: The hypermetabolic state resulting from sepsis, burns, or trauma affects carbohydrate metabolism in several ways, including increased glucose production, peripheral glucose uptake, and insulin resistance.

Benefits of Mobilization

Mobilization is a simple intervention that disrupts the adverse effects of surgery and immobilization and restores baseline physiology. Early mobilization is associated with improved restoration of functional capacity and reduced risk of secondary complications:

• Improved restoration of functional capacity at hospital discharge:

  • This is particularly important for older adults, who constitute a larger proportion of surgical patients and are especially susceptible to functional decline and deconditioning.

  • The American Geriatric Society advocates for increased focus on mobility during acute care and routine use of standardized mobility assessments.

• VTE prevention: A decreased rate of postoperative DVTs was one of the first documented findings associated with early mobilization as it gained popularity in the 1940s. This finding has been replicated among critically ill patients.

  • Although evidence is not strong that ambulation alone is sufficient to prevent VTE, it remains a mainstay of VTE prevention.

  • In patients who have undergone general, vascular, or thoracic surgery and have a low calculated risk of VTE (based on the Caprini score), ambulation and pneumatic compression boots are considered sufficient preventative measures.

  • Patients who have higher Caprini risk profiles or who underwent orthopedic procedures are still encouraged to ambulate, even if they also receive pharmacologic agents (e.g., heparin).

• Improved pulmonary function: Decreasing the time spent in bed and increasing the time spent sitting up and walking increase functional residual capacity and lung aeration.

  • Interventions that include early mobilization are associated with decreased incidence of pneumonia in surgical and critically ill patients, especially those who are mechanically ventilated.

• Decreased delirium: Although the mechanism is unclear, early mobilization, in combination with other practices (e.g., shades up during the day, regular reorientation), may decrease the risk for postoperative delirium.

• Return of bowel function: Ambulation is often encouraged in patients with postoperative ileus.

• Insulin sensitivity: Return to activity is thought to prevent and reverse immobility-associated insulin resistance, which is suspected to arise in the skeletal muscles.

• Increased sense of agency: Mobilization facilitates physical recovery, empowers patients to contribute to their recovery, and contributes to their overall well-being.

Implementation of Mobilization Interventions

How soon after surgery and how much should patients mobilize? Although the exact answer depends on the specific clinical scenario, in general, the sooner, the better. Evidence-based guidelines do not exist on the optimal or minimum amount of mobilization needed for positive effects after different types of surgery. Mobilization may start with active or resistive range-of-motion exercises and position changes in bed, followed by sitting up in bed, standing, transferring to a chair, and eventual ambulation.

(Courtesy of Michael Kochis, MD.)

Mobilization in Specific Clinical Scenarios

Critical illness:

• Extensive research supports the use of early mobilization in the intensive care unit (ICU) setting.

• Despite concerns that early ambulation increases the risk of falls, even in the ICU, the incidence of potential safety events is low, highlighting that benefits of early mobilization outweigh risks.

General and thoracic surgery:

• Standard practice is to encourage some mobilization following routine general surgery procedures a few hours after awakening from anesthesia or at least within the first 24 hours.

• Patients should be directed through a stepwise progression of activity; a reasonable expectation for an otherwise ambulatory patient is to walk the halls multiple times a day.

• Mobilization following laparotomy may cause increased pain and should be treated accordingly.

• In patients with chest tubes following thoracic surgery, the associated discomfort and encumbrance can present barriers to, but should not preclude, ambulation. Patients may require additional pain control or support.

• After hospital discharge, patients are encouraged to continue walking without distance or time limitations.

  • Patients who have undergone laparotomy are advised to avoid strenuous activities (especially bracing the core) for several weeks postoperatively to decrease the risk of incisional hernia development.

  • Restrictions are usually relaxed for minimally invasive procedures.

Orthopedic surgery:

For planned procedures (e.g., knee arthroplasties), rehabilitation including range-of-motion exercises begins hours after the operation.

• Weight-bearing status may be partial or full, depending on the technique used.

  • Patients must be educated on the specifics of restrictions and provided assistive devices to adhere to restrictions safely.

  • Hinged knee braces allow gradual increase of range of motion by a few degrees every couple of weeks.

• Even following fracture surgery, early mobilization has been a foundational management principle for more than a half century.

  • Following arthroplasties and fracture operations, continuous-motion machines are sometimes employed in addition to routine physical therapy to stretch the affected joint even as patients lie in bed.

Postoperative Pathways

Ambulation instructions are often included as part of comprehensive pathways designed to streamline recovery and counteract the adverse physiological consequences of surgical stress and immobilization.

• The first Enhanced Recovery After Surgery (ERAS) protocol was developed in the late 1990s for colorectal surgery but has since expanded to more than 20 surgical specialties (including bariatric, urology, thoracic, orthopedics, and emergency laparotomy protocols).

  • Early mobilization is a fundamental component of ERAS.

  • ERAS incorporates numerous interventions across the preoperative, intraoperative, and postoperative periods.

  • The interventions are complementary (e.g., multimodal analgesia and removal of surgical drains and urinary catheters also facilitate ambulation).

• I COUGH is a program to reduce postoperative pulmonary complications. The acronym represents the suite of interventions: incentive spirometry, coughing and deep breathing, oral care (brushing teeth and using mouthwash twice daily), understanding (patient and family education), getting out of bed at least three times daily, and head-of-bed elevation.

Interprofessional and Patient Collaboration

Although mobilization does not require many material resources, it does require buy-in from the entire health care team and, more importantly, from the patients themselves.

• Collaboration between the patient and health care team can increase patients’ self-efficacy in managing their postoperative rehabilitation.

• Patients who are involved in their rehabilitation goal setting are more likely to adhere to a prescribed program.

• Team members should make efforts to:

  • Educate patients and caregivers about the importance of mobilization both in the hospital and at home. Enlist caregivers to support motivation and implementation.

  • Enhance patient motivation by ensuring adequate pain control, removing cumbersome tubes, and providing necessary resources (e.g., assistive devices).

  • Pay careful attention to patients from minoritized and marginalized populations who experience poorer rates of recovery postoperatively, potentially due to disparities in the care received.

    • Race, socioeconomic status, health literacy, and other social determinants of health affect patients’ postsurgical outcomes.

    • Patients with low health literacy or poorly controlled pain may be hesitant to mobilize postoperatively due to pain or the fear of causing damage to the surgical site.

    • Racial disparities and biases in the assessment and treatment of pain should be acknowledged and can be overcome.

• Nurses and physical therapists (PTs) usually implement mobilization interventions with patients.

  • Inadequate personnel staffing or poor teamwork are barriers to successful mobilization and opportunities for quality improvement initiatives.

  • PT involvement is associated with higher likelihood of mobilization and greater levels of mobilization.

• Occupational therapists (OTs) can assist in mobilization, particularly recovering or achieving the ability to perform day-to-day activities.

  • OTs are particularly helpful for patients with upper-extremity impairments or other injuries that impair the ability to ambulate.

  • OTs can provide assistive devices for mobilization (e.g., crutches or walkers).

• Physiatrists (physicians specialized in Physical Medicine and Rehabilitation) may be helpful for surgical patients with anticipated prolonged recoveries (e.g., after trauma).

• After hospital discharge, some patients may require ongoing support from physiatrists, PT, OT, and specially trained nurses at an inpatient rehabilitation facility (IRF) or skilled nursing facility (SNF).

  • Input from nurses, PT, and OT is essential in determining appropriate discharge disposition.

  • The focus at IRFs is to help patients return home.

    • Patients are expected to participate in rehabilitation activities for at least 3 hours per day, 5 days per week.

    • The average length of stay at an IRF is 2 weeks.

    • Caregivers can receive further education on continuing rehabilitation at home.

  • Patients with slower expected recoveries may be better served at an SNF.

    • SNFs place greater emphasis on custodial nursing care and involve less intensive rehabilitation activities.

    • The average length of stay at an SNF is 4 weeks.