Intervention
RPE
All patients were assigned to a personalized prehabilitation regimen aimed at increasing physiologic reserve, the duration of which was tailored to the 4–6 week time lag typically required for surgical scheduling. In addition to nutritional coaching and clinically indicated supplementation, an exercise training regimen designed to addresses physiologic challenges pertinent to enduring surgery and recovery was initiated, with exercises oriented to strength (peripheral and respiratory), endurance, and coordination. Safety was ensured by beginning all exercise in a telemetry-monitored, hospital-based setting to train patients in the prescribed exercises and establish safe targets of exertion. After establishing safety, exercise commenced in the home with the goal of daily exercise. Abdominal surgical patients continued twice weekly exercise in a supervised session in a hospital-based rehabilitation clinic; cardiac and thoracic surgery patients transitioned to exclusively home-based exercise training with weekly telephone contact to ensure safety and reinforce technique. Exercise was monitored by an exercise physiologist with experience in cardiac rehabilitation techniques. If the surgery was delayed beyond 6 weeks, exercise training was continued with every other week on-site assessments until the date of surgery.Skeletal muscle strength training relied on body weight and resistance bands focusing on a spectrum of agonist and antagonist muscles to support core abdominal and thoracic muscles impacted by surgery. Training consisted of specific exercises assigned by the exercise physiologist depending on the specific surgery and the patient’s baseline function and need. Exertion was targeted according to the Borg Rating of Perceived Exertion (RPE) with a goal of RPE 11–13.Respiratory muscle training relied on IMT using a RespironicsTM spirometer that features an adjustable, spring-loaded valve that prohibits subjects from inhaling until a specific negative pressure is achieved. Patients were instructed to inspire through the mouthpiece at a comfortable rate using diaphragmatic breathing techniques while wearing a nose clip. IMT was set at 40% of each patient’s maximal inspiratory pressure (MIP) as measured in clinic by a calibrated manometer and involved 5–20 breaths depending on patients’ capacity with a goal of moderate exertion (RPE 11–13). The Threshold IMT resistance was increased as indicated during biweekly clinic visits when MIP and RPE were reassessed.Aerobic exercise relied on walking and/or cycle ergometry (upper or lower extremity). After a 3–5 minute warm-up at a low intensity (RPE 7–9), patients were coached to achieve 30 minutes of continuous moderate exertion (RPE 11–13). If 30 consecutive minutes were beyond the patient’s capacity, the patient worked up to this goal through bouts of ≥10 minutes. If any exertion induced cardiac symptoms, the target was adjusted down until a safe level was established.Coordination training involved exercises designed to strengthen the proper form of transitional movements required after surgery such as lying-to-side-lying, side-lying-to-sitting, seated scooting, and sitting-to-standing. Other coordination exercises included elements of static, tandem, and one-foot stands, weight shifts, side steps, crossovers, grape vines, backward walking, and stepping over objects. Such coordination is required postoperatively to move from bed to chair to toilet, and deficits therein may extend acute hospital stays or mandate discharge to a skilled nursing facility.