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pl. pneumothoraces [pneumo- + thorax]
A collection of air or gas in the pleural cavity. The gas enters following a perforation through the chest wall (due to traumatic or iatrogenic injury) or the pleura (from the rupture of an emphysematous bleb or superficial lung abscess) Some tall, slender young men and women suffer repeated episodes of spontaneous pneumothorax.
The onset is sudden, usually with a severe sharp pain in the side of the chest, and dyspnea. The physical signs are those of a distended unilateral chest, increased resonance, decrease in or absence of breath sounds, and, if fluid is present, a splashing sound on succussion (shaking) of the patient. Patients often report chest pain is worsened by coughing, deep breathing, or movement.
Chest x-rays confirm the diagnosis, revealing air in the pleural space, often identified as a line seen outlining a partially collapsed lung. A shift of the mediastinum toward one side of the chest or the other may be seen in tension pneumothorax.
SEE: tension pneumothorax
Treatment varies according to the type and amount of lung collapse and the preferences of the surgeon. Small spontaneous pneumothoraces may be treated conservatively with rest or needle aspiration. Larger pneumothoraces can be treated with chest tube thoracostomy or insertion of pigtail catheters with one-way valves. Traumatic or iatrogenic pneumothorax requires chest tube insertion to closed (water-sealed) chest drainage for lung reexpansion. Surgical repair also may be required. Spontaneous pneumothorax may be treated conservatively with bedrest if there is no sign of increased pleural pressure, less than 15% lung collapse, no dyspnea or other indication of physiological compromise. If the patient's condition worsens or if more than 15% of the lung is collapsed, a thoracostomy tube may be placed anteriorly in the second intercostal space and attached to a Heimlich flutter valve or chest-drainage unit. If fluid is present in the pleural space, a thoracostomy tube is placed in the fourth, fifth, or sixth intercostal space more posteriorly to drain it.
The patient's vital signs, chest expansion, oximetry and/or blood gases are monitored and oxygen administered to prevent hypoxia. The purpose and process for placing a chest tube are explained to the patient to allay anxiety and foster cooperation with the procedure. After the surgeon prepares and drapes the patient in sterile fashion, and administers local anesthesia, a small incision is made. A thoracostomy tube is attached to a water-sealed drainage device. The patient is placed in the semi-Fowler position to promote drainage, comfort, and ease of breathing. Vital signs and ventilatory status are monitored. Once the tube is placed, deep breathing (incentive spirometry) and coughing are encouraged (at least hourly) to promote lung expansion, with prescribed analgesics provided to control pain and discomfort (due in part to the tube itself). Ambulation is encouraged to facilitate full inspiration and enhance lung expansion. The thoracostomy tube site is kept sealed, generally by using a purse-string suture and occlusive dressing. Care is taken to avoid tension on the tubing, and all connections also are sealed to avoid air leaks. If the tube is accidentally dislodged, an occlusive (petroleum gauze) dressing is placed over the opening immediately to prevent lung collapse. When chest x-ray demonstrates adequate lung reexpansion that remains stable without suction, the thoracostomy tube is carefully removed, and the incision is covered with an occlusive dressing. The importance of follow-up examination, x-ray, and any needed care is explained prior to discharge. Patients who smoke are urged to stop smoking and exercise is increased gradually as determined by follow-up evaluation.