The present subject matter relates generally to a chest wound seal for first responders. More specifically, the present invention relates to a chest wound seal that stores compactly, includes: four-sided sealing; a one-way venting valve with no rigid components; and a one-way valve and vent channel resistant to blockage from clotting; and, additionally, a chest wound seal that may be thin; flexible; conformal to body contours; aggressively adhesive to contaminated surfaces (stick and stay); highly resistant to externally-originated particulate contamination; functional when covered with patient's clothing; and configurable as venting or non-venting.
When an individual suffers a puncture wound to the chest, such as from being shot or stabbed, the wound often penetrates into the chest cavity so as to puncture the parietal pleura, visceral pleura, and sometimes even the lungs. Such a wound allows air to flow freely through the open chest wound into the chest cavity and pleural space each time the patient breathes.
The condition wherein air penetrates into the pleural space between the lung and the chest wall through a wound hole in the chest wall is an open pneumothorax. When an open pneumothorax occurs, the normal mechanism by which the lung expands is lost; i.e., the fluid adhesion of the pleural surface of the lung to the pleural surface of the chest wall. Thus, the affected lung does not expand normally when the patient inhales.
A tension pneumothorax can occur when a one-way valve is formed by the wound that allows airflow into the pleural space while preventing airflow out. In a tension pneumothorax, each inhalation traps air in the chest, increasing pressure on the lungs and ultimately causing them to collapse. Additionally, the increasing pressure pushes important organs, such as the heart, major blood vessels, and airways, toward the center of the chest. This shifting can cause further compression of the lungs and may affect the flow of blood returning to the heart. These additional complications in a tension pneumothorax make it a life threatening condition that requires immediate treatment.
For patients with an open wound to the chest, the severity of the open pneumothorax that develops can be minimized by sealing the open wound via an occlusive bandage. For proper sealing, the bandage must be air- and liquid-tight, must be flexible enough to conform to all body contours, and must have an adhesive strong and persistent enough to keep the seal in place while subject to patient movement and various body fluids. The occlusive bandage may be used to eliminate air penetrating into the pleural space through the wound hole when the patient inhales.
In addition to developing a tension pneumothorax by air leakage through the chest wound, a patient with an open chest wound that is covered by an occlusive chest bandage may also develop a tension pneumothorax in a different manner. For instance, the bandage may have eliminated air from entering the pleural space through the wound hole, yet if lacerated, the lung will continue to leak air into the pleural space. Consequently, every time the patient inhales, more air becomes trapped in the pleural space, causing more pressure to be exerted on the lacerated lung. Again, this increased pressure on the lacerated lung forces the lung to collapse.
To successfully prevent a tension pneumothorax from developing, the air flow into the pleural space via the wound hole must be eliminated, but the air coming from the lacerated lung must be allowed to escape the pleural space via the wound hole.
Therefore, a need exists for a compact, low profile, adhesive chest wound seal for use by first responders that includes a one-way valve that ensures effective venting of air and/or other fluids from the pleural cavity during exhalation while sealing a chest wound against air entry during inhalation, without risk of being dislodged during treatment of the patient.
U.S. Pat. No. 5,478,333 to Asherman (“Asherman”) discloses a one-way valve apparatus installed in a chest wound seal to be used for treating a tension pneumothorax, as well as treat hemothorax (blood accumulation in the pleural cavity). The adhesive used on Asherman fails when exposed to bodily fluids such as blood or sweat. If the adhesive fails, then Asherman will not exhibit a 4-sided seal, rendering its air-ingress-during-inhalation-prevention function useless.
In addition, the design of Asherman will only allow air egress during exhalation if the valve apparatus is free of encumbrances, such as clothing, impinging on the valve exit end. Such interference will kink the valve shut, rendering it inoperative, and thereby turning Asherman into a simple occlusive chest wound seal. Further, Asherman will also not vent if the patient is lying upon the chest wound/vent, which will also kink the vent exit. Such a condition will prevent air ingress during inhalation, but will also prevent air/fluid egress during exhalation, a situation that can lead to formation of a life-threatening tension pneumothorax.
U.S. Pat. No. 7,504,549 to Castellani et al. (“Hyfin”) discloses a one-way valve fabricated as an integral part of a thin, flexible chest wound seal that claims to prevent tension pneumothorax. Hyfin discloses that its drainage channel terminates at the peripheral edge of the chest wound seal. The lack of a full perimeter of adhesive (hydrogel) in combination with a thin and flexible backing sheet can allow the Hyfin to fold along its drainage channel and allow the two sides of that channel to contact each other during Hyfin application, causing the channel to close upon itself. The hydrogel is aggressively sticky, and once stuck to itself, cannot easily be separated to reopen the occlusion in the channel.
U.S. Pat. No. 7,834,231 to Biddle et al. (“Biddle”) discloses a plurality of one-way valve apparati installed in a thin, flexible chest wound seal that claims to prevent tension pneumothorax. Biddle contains a one-way valve with a fibrous filter in line with the air flow path. The limited clear egress fluid path will be prone to blockage if the blood from the chest wound clots. Clotting will render Biddle a simple occlusive chest wound seal.
In addition, the one-way valve mechanism is subject to interference by externally originated particulate contamination, which can prevent valve closure during inhalation. If a valve fails to seal during inhalation, air can enter the pleural space through the chest wound and cause the formation of a life-threatening tension pneumothorax.
U.S. Pat. Appl. No. US 2012/0046582 to Hopman et al. (“Hopman”)—discloses a one-way valve apparatus installed in a chest wound seal that claims to prevent tension pneumothorax. The Hopman valve is a rigid, bulky one-way valve apparatus. The Hopman valve is susceptible to externally originated particulate contamination, which can prevent valve closure during inhalation. If the valve fails to seal during inhalation, air can enter the pleural space through the chest wound and cause the formation of a life-threatening tension pneumothorax.
The one-way valve can be protected from external contaminants by replacing its removable cover, but with the cover in place, the vent is rendered inoperative, thereby turning Hopman into a simple occlusive chest wound seal. Such a condition will prevent air ingress during inhalation, but will also prevent air/fluid egress during exhalation, a situation that can lead to formation of a life-threatening tension pneumothorax.
In addition, the rigid, bulky one-way valve apparatus of Hopman protrudes approximately ⅝ of an inch above the top surface of the chest wound seal. This bulkiness ensures that fewer of the units can be carried in first responder kits than other thinner, more flexible chest wound seals.
Accordingly, there is a need for a chest wound seal for first responders that stores compactly, includes: four-sided sealing; a one-way venting valve with no rigid components; and a one-way valve and vent channel resistant to blockage from clotting; and, additionally, is thin; flexible; conformal to body contours; aggressively adhesive to contaminated surfaces (stick and stay); highly resistant to externally-originated particulate contamination; functional when covered with patient's clothing; and configurable as venting or non-venting, as described herein.