Page 15 - JSOM Spring 2024

Pressures were recorded every second and marked at audible artery or posterior tibial artery for thighs) was monitored with
pulse gone and return. audible Doppler (Ultrasonic Doppler Flow Detector Model
811 with 9.5MHz adult flat probe; Parks Medical Electronics,
Tourniquet Applications www.parksmed.com). Pulse gone was defined as loss of the au-
Each TPT2 application was directly on skin. In each appli- dible distal Doppler pulse. Pulse return was defined as return
cation, careful wrapping was done to achieve 100% side- of the audible distal Doppler pulse.
to-side overlap of the inner and outer straps. There was no
calibrated method of outer strap slack removal when pulling Once the TPT2 was in place, the stopcocks were used to allow
strap through the clipped triglide, but outer strap pull-related the following sequence: 10 seconds with the system at atmo-
folding of the inner strap at the attachment of the clip was spheric pressure, TPT2 inflation to just past pulse gone for five
avoided. pulse gone/return cycles, opening the system to atmospheric
pressure for TPT2 deflation, a second TPT2 inflation with a
Unless there was a reason not to use right limbs, applications second set of five pulse gone/returns, and opening the system
were to right distal forearms and right mid-thighs. Subjects to atmospheric pressure for TPT2 deflation before TPT2 re-
were seated. Forearm applications had the tourniqueted fore- moval. A 20mL syringe was used for inflation and pressure
arm resting on a table. Thigh applications had the knees flexed cycling of forearm applications, and a 60mL syringe was used
approximately 90 degrees with both feet resting on the floor. for thigh applications. Example pressure traces are shown in
Distal arterial flow (radial artery for forearms, dorsal pedal Figure 2.
FIGURE 2 Example forearm and thigh pressure traces.

(A) (B)
200 550
180 500
(mmHg) 160 (mmHg) 450

400
140
Pressure 120 Pressure 350
300
100
TPT2 80 TPT2 250
200
Forearm 60 Thigh 150
40
100
20 50

0 0
0 50 100 150 200 250 0 50 100 150 200 250
Time (seconds) Time (seconds)

(C)
1300
air leak past syringe plunger
1200
1100
(mmHg) 1000
900
Pressure 800 Red circles indicate pulse gones. Blue circles indicate pulse returns.
(A) Example forearm TPT2 pressure trace from subject with forearm
700
circumference of 14.8cm and systolic blood pressure of 112mmHg
(same subject as panel B). (B) Example occlusive thigh TPT2 pressure
600
TPT2 500 trace from subject with thigh circumference of 53.0cm and systolic
blood pressure of 112mmHg (same subject as panel A). (C) Example
not occlusive thigh TPT2 pressure trace from subject with thigh cir-
400
Thigh 300 cumference of 61.6cm and systolic blood pressure of 126mmHg.
200
100
0
0 50 100 150
Time (seconds)

TPT2 Pressures | 13