Vented Chest Seals for Prevention of Tension Pneumothorax in a Communicating Pneumothorax

A Case of Tension Subcutaneous Emphysema Treated With Minimally Invasive Open-Window Thoracostomy Using a Wound Protector/Retractor and Three-Sided Taping

Subcutaneous emphysema is a common complication of thoracic surgery. Tension subcutaneous emphysema that causes airway obstruction is rare but life-threatening. This report presents a patient who developed tension subcutaneous emphysema after recurrent secondary pneumothorax surgery which was treated with minimally invasive open-window thoracostomy. A wound protector/retractor and three-sided taping were successfully used to prevent air from entering the subcutaneous space via the wound while draining trapped air without creating an open pneumothorax. This approach is an option for managing subcutaneous and intrathoracic air leakage in emergency situations.

Tactical Combat Casualty Care and Wilderness Medicine: Advancing Trauma Care in Austere Environments

Tactical Combat Casualty Care (TCCC) is a set of evidence-based, best-practice prehospital trauma care guidelines customized for use on the battlefield. Military units that have trained all of their unit members in TCCC have now documented the lowest incidence of preventable deaths in the history of modern warfare and TCCC is now the standard for battlefield trauma care in the US Military. TCCC and wilderness medicine share the goal of optimizing care for patients with trauma in austere environments that impose significant challenges in both equipment and evacuation capability. This article reviews the current battlefield trauma care recommendations in TCCC and discusses their applicability to the wilderness setting.

Do vented chest seals differ in efficacy? An experimental evaluation using a swine hemopneumothorax model

OBJECTIVE

Airways compromise was the second leading cause of potentially preventable death among combat casualties. We investigated the ability of five Food and Drug Administration-approved nonocclusive chest seals (CSs) to seal a bleeding chest wound and prevent tension hemopneumothorax (HPTX) in a swine model.

METHODS

Following instrumentation, an open chest wound was created in the left thorax of spontaneously air-breathing anesthetized pigs (n = 26; 43 kg). Autologous fresh blood (226 mL) was then infused into the pleural cavity to produce HPTX. The chest wounds were then sealed with CSs. The sealant strength and venting function of CSs were challenged by infusion of 50 mL more blood directly into the chest wound and incremental air injections into the pleural cavity. Tension HPTX was defined as intrapleural (IP) pressure equal to or more than +1 mm Hg and more than 20% deviation in physiologic measurements.

RESULTS

An open chest wound with HPTX raised IP pressure (~ -0.7 mm Hg) and caused labored breathing and reductions in PaO2 and SvO2 (p < 0.01). Sealing the wounds with the CSs restored IP pressure, and improved breathing and oxygenation. Subsequent blood infusion into the wound and IP air injections produced CS-dependent responses. Chest seals with one-way valves (Bolin and SAM) did not evacuate the blood efficiently; pooled blood either detached the CSs from skin and leaked out (75%), or clotted and clogged the valve and led to tension HPTX (25%). Conversely, CSs with laminar venting channels allowed escape of blood and air from the pleural cavity and maintained IP pressure and oxygenation near normal levels. Success rates were 100% for Sentinel and Russell (6/6); 67% for HyFin (4/6); 25% for SAM (1/4); and 0% for Bolin (0/4) CSs (p = 0.002).

CONCLUSION

The sealant and valve function of vented CS differed widely in the presence of bleeding chest wounds. Medics should be equipped with more effective CSs for treating HPTX in the field.

Adherence evaluation of vented chest seals in a swine skin model

OBJECTIVES

Perforation of the chest (open pneumothorax) with and without lung injury can cause air accumulation in the chest, positive intrapleural pressure and lead to tension pneumothorax if untreated. The performance of chest seals to prevent tension physiology depends partially on their ability to adhere to the skin and seal the chest wound. Novel non-occlusive vented chest seals were assessed for their adhesiveness on skin of live swine under normal and extreme environmental conditions to simulate austere battlefield conditions.

METHODS

Chest seals were applied on the back of the swine on skin that was soiled by various environmental contaminants to represent battlefield situations. A peeling (horizontal rim peeling) and detachment and breaching (vertical pulling) techniques were used to quantify the adhesive performance of vented chest seals. Among eight initially selected vented seals, five (Bolin, Russell, Fast breathe, Hyfin and SAM) were further down-selected based on their superior adherence scores at ambient temperatures. The adherence of these seals was then assessed after approximately 17h storage at extreme cold (-19.5°C) and hot (71.5°C) temperatures.

RESULTS

Adherence scores for peeling (above 90%) and detachment scores (less than 25%) were comparable for four vented chest seals when tested at ambient temperature, except for the Bolin seal which had higher breaching. Under extreme storage temperatures, adherence peeling scores were comparable to those at ambient temperatures for four chest seals. Scores were significantly lower for the Bolin seal at extreme temperatures. This seal also had the highest detachment and breaching scores. In contrast, the Russell, Fast breathe, Hyfin and SAM seals showed similar ability to stay air tight without breaching after hot storage.

CONCLUSION

No significant difference was found in skin adherence of the five vented chest seals at ambient temperature and the four seals (Russell, Fast breathe, Hyfin and SAM) maintained superior adherence even after exposure to extreme temperatures compared to the Bolin. To select the most effective product from the 5 selected vented chest seals, further functional evaluation of the valve of these chest seals on a chest wound with the potential for tension in the pneumothorax or hemopneumothorax is warranted.