THE USE OF ROUTINE PREOPERATIVE BLOOD TESTS: AN OVERUSED REQUEST (2012)

The main purpose of preoperative blood tests is to provide information to reduce the possible harm or increase the benefit to patients by altering their clinical management if necessary. This information may help clinicians assess the risk to the patient, predict postoperative complications and establish a baseline measurement for later reference. National Institute of Clinical Excellence (NICE) has issued guidelines around the need for pre-operative blood tests related to the age of the patient, comorbidities and the complexity of the procedure they will undergo. We decided to retrospectively review the pre-operative blood requests for patients under the age of 65 who were admitted at our institution over a 2 month period for open reduction and internal fixation of the ankle or tibial plateau and manipulation under anaesthesia of the lower limb. Patients were divided into 2 groups, under the age of 40 and between 40-65 years old. Patients under the age of 18 were excluded. These surgical procedures were classified as ‘intermediate complexity’. Admission clerkings of our 63 patient cohort were reviewed to ascertain if any patients had a significant co-morbidity or past medical history. The pre operative blood tests requested for each patient were audited against the NICE recommendations. None of the patients under the age of 40 had any significant comorbidites, whilst 8 patients above the age of 40 suffered with hypertension. 95% of patients had at least one blood test carried out. All patients over the age of 40 had at least one blood test. Tests requested included full blood count (91%), urea and electrolytes (91%), coagulation (66%), liver function tests (67%), group and save (69%), CRP (70%), ESR (2%), thyroid function tests (5%) and CK (2%). Only 5 patients (5%) followed the guidelines correctly. The clinical value of testing healthy individuals before an operation is debatable. The possible benefits of routine preoperative investigations include identification of unsuspected conditions that may require treatment before surgery or a change in surgical or anaesthetic management. The American Society of Anaesthesiologists has stated that ‘routine preoperative tests (i.e. tests intended to discover a disease or disorder in an asymptomatic patient) do not make an important contribution to the process of perioperative assessment and management of the patient by the anaesthesiologist.’ The overzealous requesting of preoperative blood tests also has a financial burden upon individual institutions. Our study also showed that some blood tests, such as inflammatory markers and thyroid function tests, were inappropriately requested. Adherence to the NICE guidelines would have resulted in a significant financial saving. This review has shown that adopting the NICE guidelines may result in a decrease in the amount of unnecessary blood tests patients undergo when they attend hospital for routine, minor or intermediate surgical procedures. If these guidelines were implemented for all surgical procedures, this would undoubtedly result in a significant financial saving for the institution and the NHS as a whole. At our institution we have implemented surgical and anaesthetic team awareness and education around these guidelines in a bid to reduce the use of unnecessary testing.