Pneumopericardium, pneumomediastinum and surgical emphysema in spontaneous pneumothorax

[Thyroid cartilage fracture following sneezing as a cause of spontaneous pneumomediastinum]

OBJECTIVE

To evaluate the possible etiological factors of spontaneous pneumomediastinum and to describe a case that was unusual in its etiology: a thyroid cartilage fracture as a result of sneezing.

MATERIAL AND METHODS

Six patients (four male, two female, aged 16-82 years) were hospitalized with spontaneous pneumomediastinum diagnosed with a chest X-ray in five patients and 100% with computed tomography. Treatment was symptomatic.

RESULTS

The commonest symptoms (cough, shortness of breath, hoarseness) were in four patients. Spontaneous pneumomediastinum developed in three cases as a result of bronchospasm during an attack of bronchial asthma, in one patient after exercise, in one after fibrogastroscopy, in one after sneezing. We report a 30-year-old man who presenting subcutaneous emphysema on the neck, hoarseness, pain when swallowing, hemoptysis developed after sneezing. His computed tomography revealed a pneumomediastinum due to fistula of the fracture of the thyroid cartilage following sneezing while simultaneously obstructing both nostrils. At laryngoscopy, there was a linear hematoma in the resolution stage on the anterior wall of the larynx. He was treated conservatively and recovered rapidly. There are no previous published reports of spontaneous pneumomediastinum following fracture of the thyroid cartilage.

CONCLUSION

Fracture of the thyroid cartilage as a result of a sharp rapid increase in airway pressure during a sneeze with blocked nasal passages can be one of the rare causes of spontaneous pneumomediastinum. Avoid closing both nostrils at the same time when sneezing.

Hepatic venous gas secondary to pulmonary barotrauma: rat model study

Intrahepatic gas (IHG) is commonly observed during early postmortem examinations of humans with upper or lower airway obstructions. We conducted a study to test the hypothesis that intrapulmonary gas could retrogradely spread to the hepatic vein following pulmonary barotrauma (PB). To establish a rat model of pulmonary barotrauma, we utilized a controllable pressure-vacuum pump to apply airway pressure (40, 60, or 80 mmHg). The rats were dissected directly at the end of the experiment, and histological analysis was performed through microscopic examination of the rats. Additionally, the rats were ventilated with meglumine diatrizoate under pressures of 160 and 250 mmHg to observe the signal dynamic diffusion using X-ray fluoroscopy examination. Rats exhibited classical changes associated with PB, such as alveolar rupture, pulmonary interstitial emphysema, and hemorrhage, as well as IHG characterized by the presence of gas in the hepatic vein and hepatic sinusoids. Air emboli were not observed in the liver in any of the 40 mmHg groups. However, they were observed in the liver in the 60 and 80 mmHg groups, the amount and size of air emboli in the 80 mmHg group were greater than those in the 60 mmHg group (p < 0.05). The 80 mmHg group presented radial grape-like bubbles in the centrilobular portion of the liver accompanied by congestion in the peripheral region of the hepatic lobule. X-ray fluoroscopy examination revealed a gradual enhancement of dynamic contrast medium signals from the lung to the inferior vena cava and then to the liver. Our findings indicate that pulmonary barotrauma can lead to the retrograde spread of intrapulmonary gas to the hepatic vein. When it is clear that no decomposition of the body has occurred, the presence of IHG serves as a novel indicator for the diagnosis of obstructive pulmonary disease or obstruction in the upper or lower airway.