Monitoring hypovolemia in healthy elderly subjects by measuring blood pressure response to Valsalva's maneuver.

Abstract

Quantification of hypovolemia by physical examination has limited validity. We explored the use of non-invasive measurement of blood pressure (BP) response to Valsalva's maneuver in monitoring hypovolemia in nine healthy elderly volunteers, recruited from participants of the Nijmegen Annual Four-Days Marches. Heart rate (HR), systolic and diastolic BP, and mean arterial pressure (MAP) response (Finapres) to a Valsalva's maneuver as well as clinical and laboratory assessment of fluid balance were determined 5 minutes before, and 3, 5, and 48 hours after administration of 40 mg furosemide orally. Subjects' (4 males aged 74.2 +/- 3.0 years) weight was 66.1 +/- 9.7 kg, mean BP was 139 +/- 21 over 76 +/- 12 mm Hg. A maximum weight loss of -2.8 +/- 0.9% occurred 5 hours after furosemide administration. Systolic and diastolic BP, HR, clinical assessment scores, and serum creatinine and urea nitrogen did not change during the total study period. Significant changes occurred in Valsalva phase I to phase II systolic BP response (difference +14.2 +/- 11.3 mm Hg, ratio difference -0.09 +/- 0.07 after 5 hours, P < 0.01). Changes after 48 hours did not differ from baseline values. Finapres measurement of Valsalva BP response may be useful in monitoring hypovolemia in the elderly.