Functional outcome and quality of life after iatrogenic cerebral air embolism treated with hyperbaric oxygen: a prospective cohort study

Introduction: Iatrogenic cerebral air embolism (CAE) is an uncommon, potentially fatal condition characterised by accidental introduction of air into the circulation during invasive procedures. Prompt recognition and treatment with hyperbaric oxygen therapy (HBOT) are required. Data on long-term functional outcome and specifically quality of life (QoL) in patients experiencing CAE are limited. Methods: This prospective, single-centre, observational cohort study examined patients with iatrogenic CAE who were treated with HBOT. Patient characteristics, clinical severity scores and treatment details were recorded. The primary outcomes of the study were the Glasgow Outcome Scale (GOS) score at discharge and six months, and QoL measured by the World Health Organization quality of life brief version at six months. Results: A total of 22 patients were included, with 14 patients (64%) having arterial CAE, five (23%) retrograde venous CAE, and the remaining three having either both (n = 1) or unknown (n = 2) forms of CAE. Median time-to-HBOT was seven hours [IQR 5–10]. The overall mortality rate was 23% (n = 5), eight of 22 patients achieving full recovery (GOS 5) at six months, and another six patients having moderate disability (GOS 4) at six months. Nine of 17 survivors (53%) reported a decline in QoL compared to their pre-incident status. Outcome in patients with retrograde venous CAE seemed to be better, and outcome in patients with CAE following neuroangiographic procedures for stroke or subarachnoid haemorrhage seemed to be worse, compared to the remainder of patients. Conclusions: Iatrogenic CAE is associated with substantial morbidity and mortality, with only a third of patients in our cohort achieving good functional recovery. Over half of survivors in this cohort self-reported reduced QoL as compared to their situation before the CAE incident.