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.
