Accidentally created tension pneumothorax in patient with primary spontaneous pneumothorax--confirmation of the experimental studies, putting into question the classical explanation.

BACKGROUND

The widespread explanation of patophysiology of tension pneumothorax is that compression to the mediastinum by the progressively accumulating intrapleural air causes torsion at the atrio-caval junction, impaired filling of the right heart and circulatory arrest as potentially life-threatening complication. Some experimental studies on animals put into question such an explanation, suggesting that respiratory arrest due to hypoxia of the respiratory center, not a circulatory arrest, represents dominant life threatening feature.

CASE REPORT

we present a patient with spontaneous pneumothorax in whom tension pneumothorax occurred accidentally, i.e., in whom air was insufflated under great pressure from the aspirating system into the pleural cavity, immediately after insertion of a chest tube. As the situation was recognized immediately, urgent reanimation was undertaken--endotracheal intubation, ventilation through the balloon, reconnection of the chest tube to another aspirating system. Lung reexpansion was achieved and the patient was discharged after an uneventful course. In this patient, it was possible to register the sequence of events before, during and after the incident. Dominant clinical finding during resuscitation of this apnoic, cyanotic and unconscious patient was respiratory arrest in presence of evident maintenance of peripheral circulation, that supports results of experimental studies. Dominant findings in experiments with creation of tension pneumothorax was that, although pressures rose throughout the right side of the circulation, no developing pressure gradient was found on this side of the circulation; furthermore, respiratory arrest preceded cardiac arrest in these animals. Hypoxia of the respiratory center, caused by the increasing portion of pulmonary blood flow being shunted through nonventilated or hypoventilated lung, was suggested as primary cause of death of experimental animals. The same factor seems to be a cause of respiratory arrest in our patient.

CONCLUSION

respiratory arrest, preceding circulatory arrest, seems to be the principal life threatening condition in patients with progressive tension pneumothorax.