Mediastinal tube placement in children with pneumomediastinum: hemodynamic changes and description of technique.

OBJECTIVE

To describe the technique, hemodynamic response, and complication rate after the insertion of a percutaneous mediastinal tube for drainage of pneumomediastinum.

DESIGN

A combined retrospective and prospective study in mechanically ventilated children with pneumomediastinum.

SETTING

Multidisciplinary pediatric intensive care unit at a children's hospital.

PATIENTS

The medical records and chest radiographs of 25 (15 retrospective and 10 prospective) patients who had placement of a mediastinal tube for drainage of pneumomediastinum from 1990 to 1995 were reviewed. Hemodynamic data were collected prospectively in the ten consecutive children from January 1994 to April 1995.

INTERVENTION

Mediastinal tube placement: The subxyphoid area was cleansed with povidone-iodine and draped. An 18-gauge, thin-walled introducer needle was inserted 1 to 2 cm below the xyphoid process at an angle of 20 degrees from the anterior abdominal wall, directed at the substernal space. Either a 9-Fr or 11-Fr pericardiocentesis catheter was inserted over a wire and advanced to the third intercostal space. The catheter was secured and connected to 10 cm H2O suction, using a standard thoracostomy tube drainage device.

MEASUREMENTS AND MAIN RESULTS

The size of the mediastinal air column on a lateral chest radiograph was measured before and after placement of the mediastinal tube. The mean change in the size of the mediastinal air column was -1.6 cm (median -1.5, p < .001). In the ten prospective patients, hemodynamic data were recorded immediately before and after placement of a mediastinal tube from previously placed arterial and central venous pressure catheters. The mean hemodynamic changes after the mediastinal tube placement were: heart rate -4 beats/min (median = -1, p = .14); systolic blood pressure 16 mm Hg (median = 10, p = .007); diastolic blood pressure 11 mm Hg (median = 11, p = .005); mean arterial pressure 12 mm Hg (median = 8, p = .005); and central venous pressure -2 mm Hg (median = -1, p = .04). In four patients with pulmonary artery thermodilution catheters, the mean increase in cardiac index immediately following placement of the mediastinal tube was 34%. No complications, including bleeding, cardiac puncture, or infection occurred.

CONCLUSIONS

These findings suggest that hemodynamic compromise commonly accompanies pneumomediastinum in children. Decompression of the mediastinal space and drainage of the pneumomediastinum, using this simple bedside technique for continuous drainage, can be performed rapidly and safely in children, resulting in immediate hemodynamic improvement, and allowing for continuous drainage.