The incidence of cardiac arrest requiring defibrillation and defibrillation protocols in Australasian hyperbaric units

Introduction: Cardiac arrest (CA) during hyperbaric oxygen treatment (HBOT) is exceedingly rare with only a few cases reported. It is unknown if in-chamber defibrillation of a patient has been performed in Australasia. In-chamber defibrillation is potentially dangerous with the risk of fire in an oxygen-rich environment. Australasian Standards prohibit the use of currently available defibrillators licensed for in-chamber use, as they contain lithium batteries. This study aimed to investigate how CA is managed in Australasian hyperbaric medicine units (HMUs) and to establish if there is a need to develop standardised protocols. Methods: A 10-part SurveyMonkey® questionnaire sent to all 15 Australasian HMUs. Questions aimed to ascertain if there were cases where defibrillation during HBOT was indicated and if it was performed. We asked about emergency treatment protocols, defibrillation capabilities and if regular training drills were conducted. We asked if colleagues felt the need to have a uniform treatment protocol across Australasia and invited them to share their emergency protocols. Results: Fourteen responses (93.3%) were received. No clinical cases of in-chamber CA or defibrillation were reported. Examples of emergency treatment protocols were provided by two respondents. Six respondents (43%) stated that regular emergency training drills for CA are performed in their HMU. Eleven respondents (79%) favoured standardised treatment protocols; however, comments suggested that this might be unachievable. Conclusions: CA requiring defibrillation in the hyperbaric medicine context is rare and has not been performed in Australasia. Most HMUs have protocols in place, but they are not universally practiced regularly.