Not Just a Bad Day: A Swiss Cheese Model Analysis of Anaesthetic Adverse Events

Patient safety in anaesthesia has been significantly improved through system-based approaches to error prevention. The Swiss Cheese Model conceptualises how adverse events result from the alignment of multiple failures (or “holes”) across successive layers of defence. In anaesthesia practice, this model has been widely applied to enhance safety, reduce risks, and prevent system errors. This article reviews the general application of the Swiss Cheese Model in anaesthesia and illustrates how it underpins safety strategies such as checklists, standard monitoring, and incident reporting. It also demonstrates how multiple minor failures can combine to cause harm and how strengthening any single layer can avert catastrophe. This article also discusses important limitations of the Swiss Cheese Model and briefly introduces complementary frameworks, including Safety-II and resilience engineering, to provide a more balanced perspective on contemporary patient safety theory.