Regional blood flow after pneumatic anti-shock garment inflation

To determine whether fully inflated pneumatic anti-shock garments (PASGs) decrease blood flow to abdominal and retroperitoneal organs.

An experimental study was conducted using a convenience sample of ten healthy adults. A duplex Doppler ultrasound was used to image and measure blood flow at the aortic root (cardiac output), left carotid artery, left subclavian artery, superior mesenteric artery (SMA), left renal artery, and distal aorta. Each subject was imaged before and after inflation of all three compartments of the garment to 90 mm Hg. Data were analyzed with paired t-tests.

PASG inflation did not affect cardiac output (5.45 vs. 5.83 L/min, 95% confidence limit (CL) for mean -0.97 to 0.30, p = 0.26), left carotid artery flow (0.34 vs. 0.35 L/min, 95% CL for mean -0.06 to 0.04, p = 0.70), or left subclavian artery flow (0.12 vs. 0.11 L/min, 95% CL for mean -0.01 to 0.03, p = 0.47). Inflation did cause the aortic flow immediately distal to the renal artery to decrease markedly in all subjects (1.01 vs. 0.11 L/min, 95% CL for mean 0.79 to 1.19, p < 0.001). Flow immediately above this point appeared unaffected. Physical interference with the ultrasound probe by the garment precluded measurement of SMA or renal artery flow in five subjects. In the remaining subjects, these values did not change significantly (SMA 0.40 vs. 0.28 L/min, 95% CL for mean -0.11 to 0.33, p = 0.23; renal artery 0.44 vs. 0.51 L/min, 95% CL for mean -0.09 to 0.08, p = 0.78).

PASG inflation caused a dramatic decrease in aortic blood flow over a small area immediately distal to the renal arteries but had little or no effect above this point. This provides support for the use of PASG to decrease otherwise uncontrollable hemorrhage from the iliac, pelvic, and leg vessels, but not for injuries above them.