A survey of laboratory 'critical (alert) limits' in the UK.

INTRODUCTION

Critical or alert limits are the values of laboratory measurements that are regarded as requiring urgent clinical action and should be communicated to a clinician urgently. Despite this, there has been little evaluation of these values in the UK.

METHODS

We have conducted a survey of hospital biochemistry laboratories in the UK.

RESULTS

Ninety-four laboratories responded to the questionnaire; the response rate was not recorded. Twenty-three laboratories had derived their action limits locally from a consensus with their clinicians, experience over many years, and the literature. Only two laboratories quoted literature to support their values. Seven laboratories did not submit actual critical values. There was considerable variance in the values defined as critical by the responding laboratories.

DISCUSSION

Each laboratory needs to evaluate its own list of acutely important critical values and aim for a small number of analytes that are always communicated to the doctor, so that clinical needs are met without raising the risk of information overload.