Objective To compare the anterior with lateral mean chest wall thickness measured by bedside ultrasound in Chinese adults in order to suggest a preferred site for needle decompression in tension pneumothorax. Study design This was an observational cross-sectional study conducted in a regional hospital over three months. Subjects were recruited by convenience sampling. Chest wall thickness at the second intercostal space, mid clavicular line, fifth intercostal space, anterior axillary line and fifth intercostal space and mid axillary line was measured using ultrasound on both sides. Range, mean values and confidence intervals were calculated. Results One-hundred and fourteen subjects were recruited. The mean anterior chest wall thickness was 2.62 cm (at second intercostal space, mid-clavicular line) and mean lateral chest wall was 2.68 cm (at fifth intercostal space, anterior axillary line) and 2.87 cm (at fifth intercostal space and mid-axillary line) respectively. Chest wall thickness at fifth intercostal space and mid-axillary line was significantly greater than second intercostal space, mid-clavicular line ( p < 0.01). Chest wall thickness was greater than 5 cm in 3.5% of the study population. Conclusion There is a need for population-based guidelines. We recommend needle decompression at the second intercostal space, mid-clavicular line with a 50-mm angiocath for Chinese patients with tension pneumothorax. A lateral approach at the fifth intercostal space, anterior axillary line may be considered as an alternative in case of failure. Prehospital point-of-care ultrasound may be a useful adjunct in managing such patients.
