Early hyperbaric oxygen therapy is associated with favorable outcome in patients with iatrogenic cerebral arterial gas embolism: systematic review and individual patient data meta-analysis of observational studies

Abstract

Background Iatrogenic cerebral arterial gas embolism (CAGE) caused by invasive medical procedures may be treated with hyperbaric oxygen therapy (HBOT). Previous studies suggested that initiation of HBOT within 6–8 h is associated with higher probability of favorable outcome, when compared to time-to-HBOT beyond 8 h. We performed a group level and individual patient level meta-analysis of observational studies, to evaluate the relationship between time-to-HBOT and outcome after iatrogenic CAGE. Methods We systematically searched for studies reporting on time-to-HBOT and outcome in patients with iatrogenic CAGE. On group level, we meta-analyzed the differences between median time-to-HBOT in patients with favorable versus unfavorable outcome. On individual patient level, we analyzed the relationship between time-to-HBOT and probability of favorable outcome in a generalized linear mixed effects model. Results Group level meta-analysis (ten studies, 263 patients) shows that patients with favorable outcome were treated with HBOT 2.4 h (95% CI 0.6–9.7) earlier than patients with unfavorable outcome. The generalized linear mixed effects model (eight studies, 126 patients) shows a significant relationship between time-to-HBOT and probability of favorable outcome (p = 0.013) that remains significant after correcting for severity of manifestations (p = 0.041). Probability of favorable outcome decreases from approximately 65% when HBOT is started immediately, to 30% when HBOT is delayed for 15 h. Conclusions Increased time-to-HBOT is associated with decreased probability of favorable outcome in iatrogenic CAGE. This suggests that early initiation of HBOT in iatrogenic CAGE is of vital importance.

Fatal cerebral air embolism post esophageal endoscopy with dilatation: A case report

“…The interval from the time of the procedure till the start of HBOT is of paramount importance. 2 It has been shown that HBOT within 6 or 7 hours has a better chance of a good outcome than delayed treatment. 3,4 In this case there is no indication of the duration of the interval before hyperbaric treatment could be started.…”

“…Unfortunately, with massive amounts of air in the cerebral circulation, the outcome can be expected to be bad in some instances, even with the best care and including immediate HBOT. 2 An important aspect of the HBOT in this instance would be information about the air in the mediastinum. Since there was no ongoing air leak in this case, the expectation is that HBOT would facilitate the resorption of the air in the mediastinum.…”

“…Intensive Care, James Paget University Hospital and LHM healthcare, Great Yarmouth, UK2 North Manchester General Hospital, Manchester, Greater Manchester, UK…”

Effect of a helium and oxygen mixture on physiological parameters of rats with cerebral arterial air embolism

“…It can be assumed that hyperbaric therapy itself reduces the size of gas bubbles in blood vessels by following Boyle’s Law, which states that the surface area and volume of a gas bubble are inversely proportional to pressure. However, hyperbaric oxygen therapy (HBOT) has proven to be more effective in endogenous or exogenous gas embolism ( Fakkert et al, 2023 ; Marsh et al, 2023 ). HBOT is the most common emergency therapy for embolism.…”