Repeated hyperbaric exposure and glass ampoule safety.

INTRODUCTION: It has been our institution's policy to not place glass medication ampoules inside our hyperbaric chamber for fear of rupture. There is only a small and conflicting amount of data as to whether glass ampoules are safe for use under hyperbaric conditions.

OBJECTIVES: The primary objective of this study was to test the safety and usability of glass medication ampoules inside a hyperbaric chamber.

METHODS: Repetitive, rapidly staged compressions and decompressions were performed on multiple different glass medications ampoules inside the medical lock of a medical hyperbaric chamber. Medication ampoules of varying sizes (1 ml to 10 ml) of medication that may be required in a hyperbaric emergency were assessed. The ampoules were rapidly compressed 100 times to pressures of 142 kPa, 183 kPa, 300 kPa, 405 kPa and 507 kPa. They were then dropped from a height of 30 cm while compressed at 507 kPa and then half the ampoules were opened while pressurized at 507 kPa.

RESULTS: No ampoules were broken during compression or decompression. No ampoules broke when dropped from 30 cm onto the chamber floor. All ampoules opened at a pressure of 507 kPa functioned normally. No lids/ampoules shattered upon opening.

CONCLUSION: This study suggests that glass medication ampoules appear to be safe for use inside a medical hyperbaric chamber at routine treatment pressures.