Page 13 - JSOM Spring 2024

Occlusion Pressures of Tactical Pneumatic Tourniquet 2"

Piper Wall, DVM, PhD *; Charisse Buising, PhD ; Dani Eernisse ;
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Taylor Rentschler ; Christopher Winters, MD ; Catherine Hackett Renner, PhD 6

ABSTRACT
Background: The Tactical Pneumatic Tourniquet 2" (TPT2, arterially occlusive circumferential pressure proximal to the
5.1cm-wide deflated) allows total average applied pressure injury. Therefore, to be effective, emergency-use limb tourni-
1,2
measurement, which should be useful toward development quets must be able to reach and maintain arterially occlusive
of emergency-use limb tourniquet certification devices. Meth- pressure when correctly applied. This requires materials and
ods: The TPT2 hand bulb was replaced with stopcocks and construction of sufficient robustness to withstand the forces
syringes, allowing filling with continuous pressure measure- to which they will be subjected during tourniquet use and re-
ment. Forearm and mid-thigh applications involved two sets quires designs that allow appliers to achieve adequate circum-
of five Doppler-based pulse gone/return pairs. Second set ferential pressure for arterial occlusion.
pulse gones were chosen a priori for occlusion pressures (pre-
liminary work indicated greater consistency in second sets). An acceptable process for certifying the effectiveness of spe-
Results: All 68 forearms occluded (30 female, 38 male, me- cific models of emergency-use limb tourniquets does not yet
dian circumference 17.8cm, range 14.6–23.5cm; median sec- exist. Considerable pressure data for arterial occlusion via
ond set of pulse gone tourniquet pressures 176mmHg, range 3.8cm-wide to 10.4cm-wide, nonpneumatic, emergency-use
128–282mmHg). Fifty-five thighs occluded (median circum- tourniquets on various limbs of healthy research subjects
ference 54.3cm, range 41.6–62.4cm; median systolic pressure exists; 3–12 however, there are problems using that data to set
126mmHg, range 102–142mmHg; median second set of pulse pressures for a certification system. Namely, nonpneumatic
gone pressures 574mmHg, range 274–1158mmHg). Thirteen tourniquets do not exert uniform circumferential pressure 4–7,13
thigh applications were stopped without occlusion because of nor uniform side-to-side pressure, 13–15 and different limbs and
concerning pressures combined with no indication of immi- different limb locations have different compressibility. This
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nent occlusion and difficulties forcing more air into the TPT2 means that pressure measuring systems that occupy a location
(3 female, 10 male, peak pressures from 958–1377mmHg, limited to between only part of the circumference of a tour-
median 1220mmHg, p<.0001 versus occluded thighs; median niquet and a portion of a limb are problematic when trying
circumference 63.3cm, range 55.0–72.9cm, p<.0001 versus to determine what total pressure in a cylindrical certification
occluded thighs; median systolic pressure 126mmHg, range device would be indicative of an arterially occlusive pressure
120–173mmHg, p<.019 versus occluded thighs). Thigh TPT2 with an emergency-use limb tourniquet applied to a person’s
impression widths on five subjects after occlusion were as fol- limb. Additionally, it is possible that the presence of a small,
lows: 3.5cm, occlusion 274mmHg; 2.8cm, occlusion 348mmHg; inflated bladder under a tourniquet may impact the arterially
2.9cm, occlusion 500mmHg; 2.8cm, occlusion 782mmHg; occlusive pressure, and the emergency-use limb tourniquet
2.7cm, occlusion 1114mmHg. Conclusions: Though probably pressures required for arterial occlusion may exceed the linear
useful to tourniquet certification, the required pressures for response range for the pressure measuring system that uses a
thigh occlusion make the TPT2 undesirable for any clinical use, small, inflated bladder under a tourniquet. 17
emergency or otherwise.
Having pressure data from a pneumatic tourniquet of suf-
Keywords: tourniquet; hemorrhage; first aid; emergency ficient length for thigh use but of a width closer to that of
treatment emergency-use limb tourniquets than to that of thigh blood
pressure cuffs is potentially critical to the emergency-use limb
tourniquet certification system development process. The Tac-
tical Pneumatic Tourniquet 2" (TPT2, Alphapointe, www.
Introduction
alphapointe.org), a 5.1cm-wide pneumatic tourniquet intended
The key to lifesaving use of emergency-use limb tourniquets for out-of-hospital use, may be that pneumatic tourniquet. As
is quickly stopping severe limb bleeding via the application of a pneumatic tourniquet, the TPT2 allows determination of
*Correspondence to piperwall@q.com
1 Dr. Wall is a researcher in the Department of Research, UnityPoint Health Iowa Methodist Medical Center, Des Moines, IA. Dr. Buising is a pro-
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fessor of biology at Drake University, Des Moines, IA. Dani Eernisse and Taylor Rentschler were undergraduate researchers at Drake University.
5 Dr. Winters is a surgical resident at UnityPoint Health Iowa Methodist Medical Center, Des Moines, IA. Dr. Renner is a volunteer researcher,
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UnityPoint Health Iowa Methodist Medical Center, Des Moines, IA.
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