Needle Thoracostomy in Trauma Patients: What Catheter Length Is Adequate?

OBJECTIVES: Needle thoracostomy is performed in unstable trauma patients to decompress a suspected tension pneumothorax. The current ATLS manual recommends use of a 2 inch (5 cm) long catheter to perform this procedure. Our hypothesis is that a 5 cm catheter may not decompress a tension pneumothorax in many trauma patients. We report the frequency of patients encountered at our institution that we suspect would not receive adequate pleural decompression with the use of the recommended catheter length. METHODS: We retrospectively evaluated chest wall thickness in a random sample of 30 adult male trauma patients who had a chest CT scan as part of their initial trauma evaluation at our Level 1 Trauma Center from January 2000 to April 2002. The chest depth was measured in centimeters at the second intercostal space in the midclavicular line from the skin to internal pleural border, perpendicular to the horizontal axis in each patient. After training in measurement technique, three radiologists, blinded to each others' observations, independently measured the chest wall thickness. A multi-rater kappa statistic measured agreement. RESULTS: The mean chest wall thickness was 4.6 +/- 0.2 cm. Ten of thirty (33%, 95% confidence interval (CI): 17.9%-52.9%) patients had a chest wall thickness exceeding 5 centimeters. Three of 30 (10%, 95% CI: 2.6%-27.7%) had a chest wall thickness that exceeding 6 cm. Kappa statistic for the three raters was 0.34 (95% CI: 0.13, 0.55). CONCLUSIONS: This small study demonstrates that one-third of trauma patients admitted to our facility have a chest wall thickness greater than 5 centimeters. The standard catheter may not provide effective pleural decompression in these patients. If the recommended catheter length were increased to 6 cm 90% would have successful chest wall penetration. If clinical improvement does not occur following initial attempt at pleural decompression with a standard catheter, a longer catheter should be considered.