Evidence based medicine (EBM) involves caring for patients by explicitly integrating clinical research evidence with pathophysiologic reasoning, caregiver experience, and patient preferences. This definition highlights the fact that for some decisions, patient preferences may be the dominant consideration (e.g., end-of-life decisions). It follows that other decisions may be based primarily on clinician judgement (e.g., management of rare conditions that have been poorly studied, but about which the clinician has a great deal of experience). Still other decisions may be primarily informed by rigorous clinical studies (e.g., management of variceal upper gastrointestinal bleeding for which hundreds of randomized trials and several meta-analyses exist about the effectiveness of pharmacologic, technical, and surgical approaches).

Many decisions in the intensive care unit (ICU) are based on a strong foundation of pathophysiologic reasoning derived from observations in animals and humans. The body of clinical research evidence relevant to critical care is newer than other longer-established disciplines. The breadth of the CCU clinical research base may be larger than anticipated because critical care is truly transdisciplinary, and relevant literature is dispersed in medical, surgical, anesthesia, and pediatrics journals. While some intensivists may be very familiar with their own fields of interest, or even the majority of clinical studies from their base discipline, few are familiar with relevant clinical CCU literature from all the disciplines that inform critical care practice.