Background: Tension pneumothorax is a life-threatening condition, requiring emergent needle decompression. The standard insertion site is the second intercostal space at the midclavicular line (2^nd ICS MCL). Recent studies have shown a higher success rate with needle decompression at the fifth intercostal space anterior to axillary line (5^th ICS AAL) because the chest wall is thinner at that point. However, no studies about this have been conducted in Thai patients.

Objective: To compare chest wall thickness at the 2^nd ICS MCL and the 5^th ICS AAL.

Materials and Methods: The present research was a cross-sectional study that reviewed elective computed tomographic angiography (CTA) images of 155 Thai patients over 18 years of age between January 2016 and July 2017. Chest wall thickness was measured from the superficial skin layer to the pleural space at the 2^nd ICS MCL and 5^th ICS AAL on both sides by a radiologist and an emergency medicine resident.

Results: Average chest wall thickness at the 5^th ICS AAL was greater than at the 2^nd ICS MCL. Female participants had thicker chest walls than male (p=0.027), and chest wall thickness increased with body mass index (p=0.008). The success rate of needle decompression performed by inserting a 16-gauge catheter at the 2^nd ICS MCL was higher than at the 5^th ICS AAL.

Conclusion: Chest wall thickness at the 5^th ICS AAL was greater than at the 2^nd ICS MCL.

Keywords: Tension pneumothorax, Needle decompression, Chest wall thickness, Emergency room, Emergency medicine

Received 5 Apr 2019 | Revised 13 Jun 2019 | Accepted 14 Jun 2019