A transcrainial doppler study in 80 young healthy females to understand cerebral hemodynamics during graded valsalva maneuvers

Background: The Valsalva maneuver is commonly performed during everyday activities such as lifting, defecation and coughing, and is characterized by changes in intrathoracic pressure that have a pronounced effect on venous return, cardiac output and blood pressures. purpose of this study was to examine the cerebral hemodynamic response to graded valsalva maneuver
Objectives: To assess cerebral hemodynamics during graded valsalva maneuvers study in 80 young healthy females using transcranial haemodynamics.
Material and Methods: 80 young female participants were recruited for the study. All participants groups were free from disease and were not taking any medication. Participants were instructed to abstain from strenuous exercise, alcohol and caffeine for at least 24 h before the experimental trial. During the experimental session each participant first stood for 5min, during which baseline measures were obtained, then completed a maximal VMs for 10 second. Following recovery, relative VMs of 30 and 90% of the maximal Valsalva pressure was performed for 10 s, the order of which was randomized between participants. These relative pressures were used to demonstrate graded cerebral blood flow velocity restriction. Each VM was separated b 5 min or until values had returned to baseline. Participants were verbally instructed what pressure and duration to obtain, immediately before the performance
Observation and Results: time to peak (Phase-I) corresponding to group statistics baseline-90% in all three variables MCAvmean, systolic MCA, Diastolic MCA is statistically not significant. In group statistics baseline-after VM (Phase-III) nadir phase in Diastolic MCAv is statistically significant. Mean arterial pressure in group statistics baseline-90% (Phase-I) is not statistically significant but group statistics baseline-after VM (Phase-III) is statistically significant (P<0.05). Time to peak MCAvmean and peak MAP during Phase-I of the MV was unaffected by Valsalva pressure (P=0.410, P=0.107). Time to nadir (Phase-III) falling the VM for MCAvmean and MAP showed significant co-relation between intensity of the VM.
Conclusion: The study is useful to understand the mechanism cerebral hyperemic reponses may have potential implications for patient care under many clinical conditions of brain injury.