Page 98 - JSOM Spring 2021

The Use of Chest Seals in Treating Sucking Chest Wounds

A Comparison of Existing Evidence and Guideline Recommendations

Valentin Kuhlwilm, MD*

ABSTRACT
Introduction: Sucking chest wounds occur when injuries pene- are the result of explosive devices or gunshot wounds. These
trate the thorax and inhalation results in air entering the pleural are more prevalent in asymmetrical conflicts with less well-
cavity. Well documented in the prehospital environment, treat- equipped Coalition forces. 1,3,6,10 Related to the many less serious
ment should be chest seal application to attempt prevention of or superficial injuries of the thorax, the mortality of penetrating
an expanding pneumothorax. However, a seal might occlude chest wounds might be even higher, with a mortality of >70%
the pathway for the escape of air and lead to a worsening ten- reported. 11,12 Quick and effective treatment during the first min-
sion pneumothorax. Methods: The author conducted a liter- utes after an injury is often provided by nonmedical personnel
ature search of studies reporting the efficacy of various chest and is crucial to a casualty’s survival, as opposed to being killed
seals for treating sucking chest wounds and the prevention in action. 13,14 The emphasis is on injuries that may be survivable.
of a tension pneumothorax. Study results were compared to Tension pneumothorax is therefore one of the most important
current international guidelines. Results/Discussion: Included and potentially survivable causes of death. 11,12,14,15
were four studies testing chest seals in a swine model of he-
mopneumothorax. Vented and unvented chest seals stabilized Penetrating chest wounds perforating the parietal pleura pose
cardiorespiratory parameters after an open pneumothorax, the risk of an open pneumothorax with lung collapse and re-
but only vented chest seals showed more success at prevent- duced blood oxygenation. 16,17 These were not reported as a
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ing a tension pneumothorax. Chest seals with flutter valves lethal injury on the battlefield. During inspiration, air can
seemed to be inferior. An additional study showed that vertical enter the pleural space through a leak in the chest wall (suck-
movements and soiled skin were more stressful on the applied ing chest wound) or through the tracheobronchial system. Air
chest seals. Eight international guidelines were identified: four favors entering through the defect and accumulating in the
focused on the tactical environment, and four appeared to be pleural space, resulting in dyspnea and hypoxemia, when the
more civilian-oriented. Only two of the civilian-oriented guide- leak in the chest wall is greater than the tracheal diameter. 18,19
lines did not prefer vented chest seals. Conclusion: Vented The leak in the chest wall may be like a one-way valve, with
chest seals seem to be superior to unvented chest seals, and air unable to leave the pleural space during expiration and
most international guidelines have updated their recommenda- intrapleural pressure rising, compromising the lung and lead-
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tions for the use of vented chest seals. However, frequent phys- ing to chest wall expansion. This higher intrapleural pres-
ical examinations for early signs of a developing or worsening sure results in compression of the inferior vena cava and a
tension pneumothorax are the best medical care. reduction in right heart cardiac output. Increasing heart rate is
an early compensatory mechanism, along with a reduction in
Keywords: open pneumothorax; sucking chest wound; tho- tidal volume; a further attempt to compensate is an increase in
racic trauma; chest seal; vented chest seal; unvented chest respiratory rate. 21,22 Positive intrapleural pressure at any point
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seal; combat medical care; tactical medicine of respiration is the definition of a tension pneumothorax.
If left untreated, a tension pneumothorax leads to central and
myocardial hypoxia, hypercapnia, and acidosis, leading to
cardiac and/or respiratory arrest. 20,22 Ventilated patients, be-
Introduction cause of the mechanical pressure on the venous backflow, are
The multiple vital organs within the thorax make injuries to more susceptible to cardiocirculatory arrest. 20
this anatomical space life-threatening. Armed conflicts to-
day indicate an incident prevalence ranging from 7.5% to The past decades have provided different treatment methods
1–5
10.5%. The Western armed forces have noted a decrease for sucking chest wounds. These began with three-sided dress-
in deadly thoracic injury within the last decades, resulting ings and later included occlusive/nonvented chest seals and,
from the systematic introduction and improvement of body more recently, vented chest seals. 24,25 Today there are many
armor. 1,6–8 The reported overall mortality of thoracic injuries chest seals available from multiple companies. The vented
ranges from 2% to >14%, 3–5,9 but this is thought to have been chest seals have laminar valves and flutter valves.
improving since World War II. 8,9
A chest seal might close the pathway for the escape of air and
At the end of the twentieth century, >90% of all injuries on the lead to a worsening tension pneumothorax. If air enters the
battlefield were penetrating injuries. Published data from recent pleural space through the tracheobronchial system or esopha-
conflicts show that most relevant and lethal thoracic injuries geal damage and has no path of escape, an open pneumothorax
*Correspondence to valentinkuhlwilm@bundeswehr.org
CPT Kuhlwilm is affiliated with the Department of Internal Medicine, German Military Hospital, Hamburg, Germany.

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