Proper catheter selection for needle thoracostomy: a height and weight-based criteria

Obesity increases the incidence of mortality in trauma patients. Current Advanced Trauma Life Support guidelines recommend using a 5-cm catheter at the second intercostal (ICS) space in the mid-clavicular line to treat tension pneumothoraces. Our study purpose was to determine whether body mass index (BMI) predicted the catheter length needed for needle thoracostomy.

We retrospectively reviewed trauma patients undergoing chest computed tomography scans January 2004 through September 2006. A BMI was calculated for each patient, and the chest wall thickness (CWT) at the second ICS in the mid-clavicular line was measured bilaterally. Patients were grouped by BMI as underweight (≤ 18.5 kg/m2), normal weight (18.6-24.9 kg/m(2)), overweight (25-29.9 kg/m(2)), or obese (≥ 30 kg/m(2)).

Three hundred twenty-six patients were included in the study; 70% were male. Ninety-four percent of patients experienced blunt trauma. Sixty-three percent of patients were involved in a motor vehicle collision. The average BMI was 29 [SD 7.8]. The average CWT was 6.2 [SD 1.9]cm on the right and 6.3 [SD 1.9]cm on the left. As BMI increased, a statistically significant (p<0.0001) CWT increase was observed in all BMI groups. There were no significant differences in ISS, ventilator days, ICU length of stay, or overall length of stay among the groups.

As BMI increases, there is a direct correlation to increasing CWT. This information could be used to quickly select an appropriate needle length for needle thoracostomy. The average patient in our study would require a catheter length of 6-6.5 cm to successfully decompress a tension pneumothorax. There are not enough regionally available data to define the needle lengths needed for needle thoracostomy. Further study is required to assess the feasibility and safety of using varying catheter lengths.