Trigger points for implementing the lymphedema prevention protocol included:
· BIS group An increase of 6.5 L-Dex units or more, which is 2 standard deviations (SDs) more than the baseline measurement.
· Tape measure group A volume increase of 5% to 10% more than the baseline measurement in the at-risk arm without a similar change in the arm that was not at risk.
Patients in the BIS group demonstrated lower and slower rates of progression to lymphedema requiring CDP; by contrast, those in the tape measure group triggered interventions earlier and more frequently (9.5 months vs 2.8 months). The researchers hypothesized that some patients have a generalized inflammatory response in the arm 3 months after surgery, which is easily picked up by tape measure. However, BIS measures more subtle increases in extracellular fluid, which may not be important in the whole arm volume change at that time. Dr Ridner and her team plan to continue to assess how triggers occur in both groups.
“Oncology nurses who function in staff positions, can use BIS to assess lymphatic status in breast cancer survivors. Then they can use this information in real time in clinic settings to inform patients about potential risks of lymphedema and risk-reduction practices. They can also provide this information to treating physicians for further assessment and potential treatment,” Dr Ridner told Oncology Nurse Advisor. “Advanced practice nurses can use BIS to determine if they need to prescribe a prevention intervention similar to the one used in our study. Then have their patients return in 28 days to see if the intervention was successful, potentially avoiding costly physical therapy referrals.”
1. Ridner SH, Dietrich MS, Cowher MS, et al. A randomized trial evaluating bioimpedance spectroscopy versus tape measurement for the prevention of lymphedema following treatment for breast cancer: interim analysis [published online May 3, 2019]. Ann Surg Oncol. doi: 10.1245/s10434-019-07344-5