Face cooling increases blood pressure during central hypovolemia
AJP Regulatory Integrative and Comparative Physiology
Published online on August 30, 2017
Abstract
A reduction in central blood volume can lead to cardiovascular decompensation (i.e., failure to maintain blood pressure). Cooling the forehead and cheeks using ice water raises blood pressure. Therefore, face cooling (FC) could be used to mitigate decreases in blood pressure during central hypovolemia. Purpose: We tested the hypothesis that FC during central hypovolemia induced by lower body negative pressure (LBNP) would increase blood pressure. Methods: Ten healthy participants (22±2 years, 3 women) completed two randomized LBNP trials on separate days. Trials began with 30 mmHg of LBNP for 6 minutes. Then, a 2.5 L plastic bag of ice water (0±0°C) (LBNP+FC) or thermoneutral water (34±1°C) (LBNP+Sham) was placed on the forehead, eyes, and cheeks during 15 minutes of LBNP at 30 mmHg. Results: Forehead temperature was lower during LBNP+FC vs. LBNP+Sham with the greatest difference at 21 minutes of LBNP (11.1±1.6 vs. 33.9±1.4°C, P < 0.001). Mean arterial pressure was greater during LBNP+FC vs. LBNP+Sham with the greatest difference at 8 minutes of LBNP (98±15 vs. 80±8 mmHg, P < 0.001). Cardiac output was higher during LBNP+FC vs. LBNP+Sham with the greatest difference at 18 minutes of LBNP (5.9±1.4 vs. 4.9±1.0 L/min, P = 0.005). Forearm cutaneous vascular resistance was greater during LBNP+FC vs. LBNP+Sham with the greatest difference at 15 minutes of LBNP (7.2±3.4 vs. 4.9±2.7 mmHg/PU, P < 0.001). Conclusion: Face cooling during LBNP increases blood pressure through increases in cardiac output and vascular resistance.