Kwak HJ, Lee D, Lee YW, Yu GY, Shinn HK, Kim JY.

Arthroscopy. 2010 Jun;26(6):729-33.

Abstract
PURPOSE: This study investigated the effect of intermittent compression by a sequential compression device (SCD) on the incidence of hypotension and other hemodynamic variables in the beach-chair position.
METHODS: Fifty healthy patients undergoing elective shoulder arthroscopy under general anesthesia were randomly assigned to either the control group (n = 25) or SCD group (n = 25). A standardized protocol for pre-hydration and anesthetic technique was followed. Hemodynamic variables were measured before (pre-induction values) and 5 minutes after the induction of anesthesia in the supine position (baseline values) and 1, 3, and 5 minutes after the patient was raised to a 70 degrees sitting position. The incidence of hypotension was recorded and treated with ephedrine.
RESULTS: The incidence of hypotension was significantly higher in the control group (16 of 25) than that in the SCD group (7 of 25) (P = .022; odds ratio, 0.219; 95% confidence interval, 0.066 to 0.723). Between the groups, mean arterial pressure, cardiac index, and stroke volume index were significantly higher in the SCD group compared with values in the control group at 1 minute after patients were raised to a 70 degrees sitting position (P = .035, P = .046, and P = .011, respectively).
CONCLUSIONS: This study showed that the use of an SCD could reduce the incidence of hypotension from 64% to 28% and supports hemodynamic variables such as mean arterial pressure and stroke volume index when patients were changed from the supine to the beach-chair position in those undergoing shoulder arthroscopy.
LEVEL OF EVIDENCE: Level I, therapeutic randomized controlled trial.