Laboratory critical values: automated notification supports effective clinical decision making.

Objective: Failure to adequately communicate a laboratory critical value (CV) is a potential cause of adverse events. The harmonization of CV reporting is increasingly recognized as a key issue in ensuring patient care and minimizing harm. With ongoing improvements in CV reporting, the patient's outcome should be audited to assess the effectiveness of CV notification.

Design And Methods: We report the data audited throughout a six month-period during which an analysis was made of CVs, and we describe the approach of clinicians and general practitioners (GPs), and their decision making following CV reporting.

Results: CV notification led to a change of treatment in 98.0% of patients admitted to surgical and in 90.6% of those admitted to medical wards. Clinicians made a further evaluation of new complications in patients in 70.0% and 60.4% of cases, in surgical and medical wards respectively. In more than 40.0% of cases, CVs were unexpected findings. In the primary care setting, critical hyperkalemia was managed by GPs in 55% of patients, thus sparing patient's hospitalization. For all outpatients with critical INR (international normalized ratio), the GPs changed or stopped warfarin dosage. Twenty-four percent of patients were checked for an additional INR, whereas a further medical examination by a consultant in the hospital setting was requested for 5% of patients.

Conclusions: The laboratory plays a key role in ensuring patient safety, especially in CV reporting. An evaluation should be made of the patient's outcome and clinical decision making in order to assess the effectiveness of the CV process.