Blood Pressure of the Normal Rhesus Monkey

Summary

Arterial blood pressures have been determined in unanesthetized monkeys by 2 indirect methods. Using a small “newborn” cuff (cloth cuff) on the upper arm and auscultation of the sounds in the brachial artery, mean blood pressure in 14 normal monkeys was found to range from 137/112 to 188/152 mm Hg with a group average of 159/127. With a cuff consisting of a rigid metal shell enclosing a rubber sleeve (metal cuff), mean pressures ranged from 103 78 to 132/101, the group average being 118 90 mm. In 27 splenectomized, but otherwise normal, monkeys the blood pressures were slightly but not significantly lower. Metal cuff pressure readings were found to be consistently less variable than corresponding cloth cuff values, the respective average standard deviations in normotensive animals being 7 and 12 mm. Blood pressures in untreated animals estimated by either indirect method were relatively stable; in no instance did mean systolic or diastolic pressure during a 12-month period vary by as much as 10 mm Hg from the mean values obtained during an initial 2-month observation period. Simultaneous comparisons of indirect (cloth or metal cuff) and direct (strain gauge) blood pressure measurements in 46 anesthetized animals indicated that the metal cuff readings were lower and the cloth cuff readings higher than measurements obtained directly in the same artery with a strain gauge. The blood pressure as measured directly with a strain gauge fell about midway between the corresponding cloth and metal cuff readings.