Difficult decisions in the intensive care unit: an illustrative case.

Difficult clinical decision-making is a common experience in intensive care units. There is often considerable pressure on time and decisions may have to be made in a stressful environment. Patients in the intensive care unit not infrequently present with extreme or rare manifestations of a disease process. Clinical evidence to guide management of such patients may be incomplete, non-existent, or its relevance to the problem at hand may be questionable. In this context, formal decision-making analytical tools are often impractical. Unconscious cognitive biases have been shown to play an important role in medical decision-making, particularly in these settings. While mostly these contribute to doctors making appropriate and timely decisions, occasionally they lead to errors. Despite 30 years of research into models of clinical reasoning, most doctors are unaware of how biases affect their thinking and are unfamiliar with techniques of detecting and neutralising bias in clinical practice. We present the case of a patient with Wegener's granulomatosis, which highlights many of the difficulties outlined above. We review the clinical evidence for our decisions at each stage and explain the rationale for our choices, highlighting the many situations for which high quality evidence was lacking. Examples of cognitive bias are identified and techniques of metacognition (thinking about thinking) that can be useful in limiting the effects of bias on complex decision-making are reviewed. The intensivist's evaluation of management alternatives has an important role in steering medical management towards optimal patient outcomes.