Does needle thoracostomy provide adequate and effective decompression of tension pneumothorax?
BACKGROUND
Tension pneumothorax (tPTX) is a common and potentially fatal event after thoracic trauma. Needle decompression is the currently accepted first-line intervention but has not been well validated. The purpose of this study was to evaluate the effectiveness of a properly placed and patent needle thoracostomy (NT) compared with standard tube thoracostomy (TT) in a swine model of tPTX.


METHODS
Six adult swine underwent instrumentation and creation of tPTX using thoracic CO2 insufflation via a balloon trocar. A continued 1 L/min insufflation was maintained to simulate an ongoing air leak. The efficacy and failure rate of NT (14 gauge) compared with TT (34F) was assessed in two separate arms: (1) tPTX with hemodynamic compromise and (2) tPTX until pulseless electrical activity (PEA) obtained. Hemodynamics was assessed at 1 and 5 minutes after each intervention.


RESULTS
A reliable and highly reproducible tPTX was created in all animals with a mean insufflation volume of 2441 mL. tPTX resulted in the systolic blood pressure declining 54% from baseline (128-58 mm Hg), cardiac output declining by 77% (7-1.6 L/min), and equalization of central venous pressure and wedge pressures. In the first arm, there were 19 tPTX events treated with NT placement. All NTs were patent on initial placement, but 5 (26%) demonstrated mechanical failure (due to kinking, obstruction, or dislodgment) within 5 minutes of placement, all associated with hemodynamic decline. Among the 14 NTs that remained patent at 5 minutes, 6 (43%) failed to relieve tension physiology for an overall failure rate of 58%. Decompression with TT was successful in relieving tPTX in 100%. In the second arm, there were 21 tPTX with PEA events treated initially with either NT (n = 14) or TT (n = 7). The NT failed to restore perfusion in nine events (64%), whereas TT was successful in 100% of events as a primary intervention and restored perfusion as a rescue intervention in eight of the nine NT failures (88%).


CONCLUSIONS
Thoracic insufflation produced a reliable and easily controlled model of tPTX. NT was associated with high failure rates for relief of tension physiology and for treatment of tPTX-induced PEA and was due to both mechanical failure and inadequate tPTX evacuation. This performance data should be considered in future NT guideline development and equipment design.
Department of Surgery, Madigan Army Medical Center, Tacoma, Washington, USA. matthew.martin1@amedd.army.mil
Matthew
M
Martin
Steven
S
Satterly
Kenji
K
Inaba
Kelly
K
Blair
D000818:Animals; D019299:Decompression, Surgical / Q000379:methods*; D004195:Disease Models, Animal; D009339:Needles; D011030:Pneumothorax / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D013552:Swine; D013898:Thoracic Injuries / Q000150:complications / Q000601:surgery; D013907:Thoracostomy / Q000379:methods*; D016896:Treatment Outcome