Tension Pneumothorax During Hyperbaric Oxygen Therapy With Pigtail Pleural Catheter: A Case Report and Experimental Flow Analysis.

Introduction: Tension pneumothorax is a life-threatening complication during hyperbaric oxygen treatment (HBO₂). The presence of a pleural catheter is assumed to mitigate this risk, but its efficiency under hyperbaric conditions remains unclear. Case Report: We describe a 37-year-old female undergoing HBO₂ with a pigtail pleural catheter in situ for secondary pneumothorax. The patient developed respiratory and cardiovascular symptoms during decompression. To investigate gas flow dynamics, we conducted an experimental analysis measuring flow resistance in pigtail catheters under chamber pressures up to a chamber gauge pressure of 172.37 kPa. Flow rates were analyzed across a range of differential pressures and catheter fenestration numbers. Gas flow increased non-linearly with pressure but plateaued at higher differentials, indicating drainage limitations. Catheters with fewer fenestrations exhibited significantly reduced flow rates. Under simulated HBO₂ conditions, pressure differentials exceeding 2.4 kPa resulted in delayed gas evacuation, mirroring the clinical event. Discussion: This case and experimental study highlight the potential risk of inadequate pneumothorax drainage with pigtail catheters during HBO₂. We recommend decompression rates ≤1 psi/min to mitigate this risk. Further studies are needed to evaluate alternative catheter designs for hyperbaric environments.