From the Guidelines
The leading cause of death from tension pneumothorax is decreased venous return (decreased preload and cardiac output). This occurs because as air accumulates in the pleural space under pressure, it pushes the mediastinum toward the unaffected side, compressing the vena cava and limiting blood return to the heart. This decreased preload results in reduced cardiac output and ultimately leads to obstructive shock and cardiovascular collapse. The compression of the heart and great vessels, rather than hypoxia or arrhythmias, is the primary mechanism of death in tension pneumothorax.
For patients with chest stab wounds who have abdominal pain and are hemodynamically compromised, laparoscopy is the best diagnostic modality to detect diaphragmatic injury, with high sensitivity (88%) and specificity (100%), allowing for direct visualization and immediate repair of any identified injuries 1. According to the World Journal of Emergency Surgery, laparoscopy is recommended in stable trauma patients with lower chest penetrating wounds and suspected diaphragmatic hernia (DH) 1.
The use of laparoscopy in this context is supported by its ability to provide direct visualization of the diaphragm and surrounding structures, allowing for accurate diagnosis and treatment of diaphragmatic injuries. Other diagnostic modalities, such as CT scans and chest X-rays, may not provide the same level of sensitivity and specificity as laparoscopy, particularly in cases where the diaphragmatic injury is small or not immediately apparent 1.
In addition, the Annals of Emergency Medicine notes that ultrasound can be a useful diagnostic tool in the assessment of hemodynamically unstable blunt abdominal trauma patients, but it may not be as sensitive or specific as laparoscopy in detecting diaphragmatic injuries 1. Therefore, laparoscopy remains the preferred diagnostic modality for detecting diaphragmatic injuries in patients with chest stab wounds and abdominal pain, due to its high sensitivity and specificity, as well as its ability to provide direct visualization and immediate repair of any identified injuries.
From the Research
Leading Cause of Death from Tension Pneumothorax
- The leading cause of death from tension pneumothorax is decreased venous return, which results in decreased preload and cardiac output 2, 3.
- This decrease in venous return can lead to a decrease in cardiac output, resulting in hypotension and ultimately cardiac arrest.
- Other options, such as cardiac arrhythmia, acute hypoxia, and acute hypercapnia, can also contribute to the morbidity and mortality associated with tension pneumothorax, but decreased venous return is the primary cause of death.
Best Modality to Detect Diaphragmatic Injury
- Laparoscopy is the best modality to detect diaphragmatic injury, with a sensitivity of 88% and specificity of 100% 4.
- Laparoscopy allows for direct visualization of the diaphragm and can help identify injuries that may not be visible on imaging studies.
- Other options, such as thoracoscopy, CT scan, and cervical spine evaluation, may also be useful in detecting diaphragmatic injury, but laparoscopy is the most sensitive and specific modality.
- In cases where laparoscopy is not possible, CT scan may be used as an alternative, especially in stable patients 2.