Local compression patterns beneath pneumatic tourniquets applied to arms and thighs of human cadavera

Abstract

Distributions of tissue fluid pressure were examined beneath a standard pneumatic tourniquet in six upper extremities and six lower extremities of fresh human cadavera, disarticulated at the shoulder and hip, respectively. A standard 8-cm-wide tourniquet cuff was applied at mid-humerus or mid-femur position. Tissue fluid pressures were measured by 100-cm-long slit catheters inserted parallel to the bone at four tissue depths: subcutaneous, subfascial, mid-muscle, and adjacent to bone. All arms and thighs were studied at the following cuff pressures: 100, 150, 200, 250, 300, 400, and 500 mm Hg. Tissue fluid pressure was always maximal in subcutaneous tissue at mid-cuff. Transmission of cuff pressures to deeper tissues was significantly less (p less than 0.01) in the thighs with a girth of 40-52 cm than in the arms with a girth of 22-33 cm. At the four tissue depths studied, tissue fluid pressures fell steeply in a longitudinal direction near the cuff edge to levels near zero at points 1-2 cm outside each cuff edge. Our results suggest that wider cuffs are required on thighs than on arms to provide a bloodless field during limb surgery and to minimize underlying tissue injury associated with high cuff pressures. Our recommendation for wider tourniquet cuffs than those presently used during orthopaedic surgery is contrary to recent prevailing knowledge.

Thermal sensation at index finger while applying external pressure at upper arm

“…With or without the external pressure, the index fingertip temperatures observed for the females (27.4 75.0 1C without pressure/ 25.274.4 1C with pressure) were lower than those for the males (31.874.5 1C without pressure/29.8 74.5 1C with pressure), as depicted in the figure. Several researchers (Kirkendall et al, 1967;Hargens et al, 1987) have reported that under the same external pressure, the main arteries in a smaller arm circumference were more susceptible to deformation: a gender difference was thus implied. It seems to be the case in our study as well.…”

Sex-related effects on venous compliance and capillary filtration in the lower limb

“…The cuff method used by Meendering et al (34,35) and Monahan and Ray (39) equals cuff pressure with venous pressure, assuming a 100% transmission of applied pressure to the underlying tissue. This is by no means certain, and transmission especially to the deep underlying tissue in the thigh may be overestimated (18). Further, thigh volume might differ between sexes, which could affect the found differences in calf venous compliance at transmural pressures relevant to HUT or quiet standing.…”

Tissue fluid pressures: From basic research tools to clinical applications

“…Transmission of cuff pressures to deeper tissues was significantly less in the 40-52-cm girth thighs than in the 22-33-cm girth arms. At the four tissue depths studied, tissue fluid pressures fell steeply in a longitudinal direction near the cuff edge to levels near 0 at a point 1-2 cm outside each cuff edge (14). In another study (2), longitudinal and radial tissue fluid pressure distributions were determined beneath and adjacent to wide (12 and 19 cm) pneumatic tourniquet cuffs placed on intact human cadaveric arms and legs.…”

“…Most previous studies of tourniquet injury have focused upon the effects of ischemia in tissues distal to the applied cuff. Importantly, however, recent studies of the effects of tissue pressures on muscles, nerves, and blood vessels directly beneath the tourniquet cuff suggest that these underlying tissues are more seriously jeopardized (14,28,38,44).…”