Patient safety, human factors and systems thinking — formative SAQs

SAQ 1 (10 marks)

A two-year-old on the ward receives ten times the intended dose of morphine because a decimal point was misread in a handwritten prescription. The child becomes bradypnoeic but is reversed with naloxone and recovers. The prescribing registrar is distressed and tearful. [12] [6]

1. Using Reason's framework, classify the type of human failure at the sharp end and identify two likely latent conditions that allowed it to reach the child. (5) [3]
2. Outline the immediate response and the subsequent system response, including how the registrar should be supported. (5) [12] [4]

Model answer

The active failure is best understood as a slip or lapse — an execution failure (a misread decimal point) rather than a wrong plan — made more likely by the paediatric need for weight-based calculation. The latent conditions are the use of a handwritten chart without dose-range checking, the absence of an independent double-check before a high-alert medicine, and the storage or formatting that allowed a tenfold error to pass. This is the meeting of an active failure with latent conditions, which is exactly what the Swiss cheese model predicts. [3] [6] [8]

The immediate response is fixed in order: make the child safe and escalate using ABCDE (here, naloxone and airway support), preserve the scene and the evidence (the chart, the infusion), and notify the responsible consultant and the safety lead the same day. The subsequent system response is to report the event, run a root cause analysis that travels from the active failure to the latent conditions rather than stopping at a name, hold an honest and apologetic open disclosure with the family, and implement and measure corrective actions such as computerised order entry with weight-based dose checking and an independent double-check of high-alert medicines. [12]

The registrar is a second victim: acute distress after involvement in an adverse event carries a real risk of further error and of leaving the profession. Provide immediate peer support, relieve them from front-line duties as appropriate, and arrange formal follow-up — in a just culture, an honest error is consoled, not punished. [4]