Although frailty is an important perioperative risk factor, interventions specific to frail surgical patients remain rare. According to a systematic review of the literature, development and evaluation of frailty-specific interventions in trials containing a low risk for bias is urgently needed.
“We know that frailty adversely affects outcomes in the elderly. Now it’s time to start doing something about it,” said Daniel I. McIsaac, MD, MPH, FRCPC, assistant professor of anesthesiology and pain medicine at University of Ottawa, in Ontario, and associate scientist at Ottawa Hospital Research Institute. “Such trials should consider perioperative exercise therapy interventions, and should follow best-practice guidelines for the development and evaluation of complex interventions.”
As Dr. McIsaac reported at the International Anesthesia Research Society 2017 annual meeting, frailty has been identified as a key predictor of mortality and morbidity in older surgical patients, with studies showing up to a threefold increase in relative risk for adverse postoperative events (abstracts 1037 and 1256).
Nonetheless, interventions targeting frail surgical patients are not commonly described. A systematic review of the literature conducted by Dr. McIsaac and his colleagues identified only 11 interventional studies specific to frail surgical patients that had the goal of improving outcomes.
“The majority of these studies were focused on exercise therapy in either the preoperative or postoperative setting,” said Dr. McIsaac, who noted that prehabilitation in total joint replacement patients was shown to improve preoperative functional measures. “Those who exercised before surgery improved their function prior to surgery, compared to the start of the program.”
The bulk of the evidence, however, dealt with rehabilitation or exercise after surgery. Studies showed that in both cardiac and orthopedic patients, postoperative exercise was associated with significant improvements in health-related quality of life and functional measures, such as balance and gait speed. Nevertheless, Dr. McIsaac said, the risk for bias was moderate to high in all studies.
“These were mostly observational studies, which tend to overstate the effect of the intervention,” Dr. McIsaac said. “In addition, the randomized controlled trials were poorly allocated, poorly blinded and had multiple outcome measurements. There’s certainly a lot of room for improvement moving forward.”
Prehabilitation to Improve Patient Function
Based on this dearth of literature, Dr. McIsaac and his colleagues intend to test the efficacy of home-based prehabilitation of frail older patients to improve their postoperative function after elective cancer surgery. Researchers are conducting a single-center, single-blind, parallel-arm, randomized controlled trial of home-based prehabilitation versus standard care in frail patients aged 65 years or older who are scheduled to undergo elective surgery for intraabdominal, thoracic or pelvic cancer. Patients will be included in the study only if they are diagnosed with frailty—based on a Clinical Frailty Scale score of at least 4 of 9—and are at least four weeks before the date of their scheduled surgery.
As Dr. McIsaac explained, intervention patients will perform a home-based total body exercise training program that consists of three components: strength, aerobics and flexibility. Participants will receive in-person teaching and video instruction to facilitate the program at home, and investigators will assess compliance by weekly phone calls.
The study’s primary outcome is a six-minute walk test at the first clinical follow-up after hospital discharge. Secondary outcomes include health-related quality of life, disability-free survival, complications, hospital length of stay, health-system costs and all-cause mortality.
“This program is based on a protocol with proven efficacy in improving the function of nonfrail surgical patients in less than four weeks of preoperative participation,” Dr. McIsaac said. “In addition to functional outcomes, we’re also focusing on patient-reported outcomes, which we believe are most important to this population. Hopefully, we’ll collect enough data on patient-reported outcome measures to do a multicenter trial, which is actually powered for these outcomes.”
Study recruitment began in January 2017. Dr. McIsaac and his colleagues plan to recruit at least 100 participants per arm.
Moderator of the session, Debra Pulley, MD, associate professor of anesthesiology at Washington University in St. Louis, asked whether previous studies have identified the most critical component of an exercise regimen, such as strength or aerobics.
“In nonperioperative literature, most frailty exercise interventions have several components, so there are not many opportunities to compare specifics,” Dr. McIsaac said. “Based on our recent 700-patient multicenter cohort study, grip strength tends to be the most predictive of bad outcomes, but gait speed is highly predictive as well.
“Nevertheless, I’m not sure if one component of exercise is going to matter more than the other,” he continued. “Outside of frailty, when you look at preoperative exercise interventions, especially in cancer surgery, patients randomized to the nonexercise group tend to drop in function from baseline. Just giving people something to do, even if [it] only keeps them at baseline, should improve their postoperative function. … Just getting patients moving is what matters.”