THE EFFECT OF THE VALSALVA MANEUVER ON EXPERIMENTALLY INDUCED PAIN: A TEST OF THE CARDIOVASCULAR PAIN REGULATING SYSTEMS INTERACTION MODEL.
Contributors: Indiana University School of Nursing.
Published: 1986
Number of pages: 248
Subjects: Health Sciences, Nursing.
Description: The purpose of this experimental study was to test the prediction that stimulation of the sinoaortic baroreceptor reflex arc, with an intervention amenable to nursing practice, modifies the perceived intensity of a noxious stimulus. The cardiovascular pain regulating systems interaction model (Randich & Maixner, 1984a) provided the theoretical basis for this study. Subjects (N = 30) volunteered to experience a pain producing procedure twice. The dependent variable pain intensity was measured by subject self-report of pain on a visual analogue scale (VAS). Six VAS ratings, three during each pain procedure, were obtained from each subject. The first VAS rating provided a baseline measure. The second and third VAS ratings were obtained 30 s and 3 min respectively after either the treatment or control intervention. The order in which subjects performed either intervention was randomly assigned.

Subjects performed the Valsalva maneuver (treatment) to elicit hemodynamic events which stimulated the sinoaortic baroreceptor reflex arc. The accompanying baroreflex mediated changes in heart rate were recorded by electrocardiography. The peak tachycardiac response during the expiratory strain component of the Valsalva maneuver was divided by the peak bradycardic response following release of the strain to determine a Valsalva ratio (Levin, 1966) for each Valsalva maneuver performed. A minimum ratio of 1.5 was required as evidence of baroreceptor mediated changes in heart rate. The control intervention consisted of normal breathing through a plastic mouthpiece.

Prior to hypothesis testing, statistical control of potentially confounding variables, such as order of treatment presentation, state anxiety and cognitive strategy use, was demonstrated. Hypothesis testing demonstrated that (1) baseline pain intensity did not differ, and (2) pain was significantly (p $<$.05) less intense 30 s and 3 min after the Valsalva maneuver than after normal breathing. The treatment effect was greatest 3 min after the Valsalva maneuver. The magnitude of the standard deviations for VAS measures of pain intensity prompted a post hoc analysis. Four treatment response patterns were identified.

The results of this study provide beginning empirical support for the Valsalva maneuver as a potential pain modulating technique with healthy subjects. Replications are needed to enhance the generalizability of these results with diverse populations.
Notes: Source: Dissertation Abstracts International, Volume: 48-08, Section: B, page: 2261.

Thesis (D.N.S.)--INDIANA UNIVERSITY SCHOOL OF NURSING, 1986.

School code: 0815.