Influence of intermittent pneumatic compression devices on non-invasive blood pressure measurement of the ankle.

Background: It is rapidly becoming the standard of care to employ the perioperative use of intermittent pneumatic compression (IPC) devices on the lower leg to prevent the development of deep venous thrombosis. There are instances when the anesthesiologist must apply a blood pressure cuff to the ankle in order to obtain a blood pressure reading. The purpose of this study is to determine the influence of IPC devices on non-invasive blood pressure measurements of the ankle.

Methods: We utilized the Flowtron Excel External Pneumatic Compression System Model AC550 and the Datascope Passport non-invasive blood pressure monitor Model EL, in 50 healthy volunteers ranging in ages from 23 to 35 who were free of systemic disease. The IPC devices were applied to both lower extremities and sequentially inflated. All blood pressure measurements (systolic, diastolic, and mean arterial pressure) were taken with the volunteer in the supine position, obtained in triplicate and then averaged. Blood pressure measurements were obtained at four time periods: 1) when the IPC device was placed over the ankle blood pressure cuff but not inflated (control) 2) 15 s prior to inflation of the IPC device 3) at inflation of the IPC device and 4) 15 s after the beginning of inflation of the IPC device. The difference between the averaged blood pressures and the control blood pressures were calculated. The resulting values were then converted to absolute values. The averaged absolute values were analyzed using ANOVA for repeated (paired) data.

Results: No statistical significant difference was shown between the control blood pressure measurements and any of the three sets of blood pressure measurements relative to IPC device inflation; 15 s prior, at onset, and 15 s after inflation. The p-values for systolic, diastolic, and MAP were respectively 0.872, 0.645 and 0.522. With these p-values, the power tests for each were >0.80.

Conclusion: The IPC device had no significant impact on non-invasive blood pressure measurement of the ankle in our study.