Just a quick post to brighten your weekend. Like many of you I have lost count of the number of times I’ve been challenged about performing a contrast CT for a critically ill/injured patient because we don’t yet know the creatinine level. Despite the evidence for contrast induced nephropathy being dubious, and large observational trials indicating that it is not a factor in subsequent renal failure the challenge has persisted.

Interestingly the challenge has usually been about the absence of a result, with a request to delay the scan until it it is known. In contrast (sic) a patient with known renal impairment and/or high creatinine was a short and satisfying conversation as we already knew what the issue was. Paradoxically, when there is uncertainty, this often led to delay. If we know what the renal function is, even if awful then there is NO delay as a ‘decision’ CAN be made. When we are waiting for a result to come back clinicians feel that there is not enough information to make a decision and so they wait. When you step back and think about it this makes almost no sense at all, but it’s the nature of humans who can comfortably handle an abnormal result, but not uncertainty

Although these terms may be heard more often in a Build-a-Bear factory or a kitchen at Christmas than a Emergency Department, it doesn’t mean they’re any less relevant. What on earth do these terms mean though and how are they relevant to our practice?