Wireless technology helped tailor mobility recovery after cardiac surgery

Wireless monitoring helped clinicians accurately assess the mobility recovery of patients after cardiac surgery, according to results of a study performed at the Mayo Clinic in Rochester, Minn.

Assessment of strength and mobility after surgery is becoming more important to hospitals and payers, but accurately acquiring functional assessments during hospitalization presents a challenge, David J. Cook, MD,FAHA, and colleagues wrote in the study background.

Measurements of mobility

Researchers assessed whether wireless accelerometry could measure mobility recovery after cardiac surgery. The study included 149 patients aged at least 50 years who had undergone elective cardiac surgery (43% valve repair or replacement; 32% CABG; 14% valve surgery and CABG).

David J. Cook

Each patient was given a wireless accelerometry device (Fitbit) placed on the ankle after transition from the ICU. The device recorded each step a patient took.

For the analysis, the researchers grouped patients by length of hospital stay (<5 days, 5 to 6 days after surgery or >6 days after surgery) and discharge disposition (to home, to home with home health care support or to a skilled-nursing facility.)

Mean length of stay after surgery was 5.3 days. Fourteen percent of patients were discharged to home with home health care support or to a skilled-nursing facility. Compared with those discharged to home independently, these patients were older (76 years vs. 67 years) and had a higher (17% vs. 10%) Society of Thoracic Surgeons risk index (P<.01 for both variables by two-sample t test).

On the second day of recovery, those patients eventually discharged to home independently took an average of 675 steps vs. an average of 108 steps for those discharged to home with home health care support or to a skilled-nursing facility (P<.001). A similar difference was observed on the third and fourth days of recovery.

By the end of the second day of recovery, patients eventually discharged after fewer than 5 days had taken a median of 818 steps vs. a median of 514 steps for those discharged after 5 to 6 days and a median of 223 steps for those discharged after more than 6 days (P=.001).

Unique results

“Although the results were not unexpected, they are unique,” Cook, professor at the Mayo Clinic College of Medicine and member of the department of anesthesiology and the Center for the Science of Health Care Delivery at the Mayo Clinic and Foundation, and colleagues wrote. “This is the first demonstration that remote monitoring of mobility is effective to assess hospital surgical recovery, and such data have implications for resource utilization and outcomes.

“Although our investigation was not designed to determine the mobility threshold predictive of early discharge or discharge to home, the data suggest mobility achieved on recovery day 2 may lead to both outcomes,” they wrote. “This opens the door for changing recovery models and improving outcomes in surgical practice.”

In a related editorial, Clare H. Ridley, MD, Joseph V. Adler, PT, DPT, and Albert T. Cheung, MD, all of the University of Pennsylvania Perelman School of Medicine, wrote that, “The application of wireless accelerometry to quantify physical activity has the potential to extend the capabilities of the physical therapy team, measure the effectiveness of rehabilitation regimens, quantify progress, and improve the ability to predict operative risk.” Further, the editorialists said they would like to see the technology tested for use in identifying patients at risk for complications such as venous thromboembolism.

For more information:

Cook DJ. Ann Thorac Surg. 2013;96:1057-1061.

Ridley CH. Ann Thorac Surg. 2013;96:1061.

Disclosure: The researchers and editorial authors report no relevant financial disclosures.