When to order anemia (ana) laboratory tests?

From the Guidelines

Ana lab should be ordered 28 days before the scheduled surgical procedure for elective orthopaedic surgical patients to determine haemoglobin (Hb) level and detect preoperative anaemia, which is associated with increased perioperative morbidity and mortality. This approach is recommended by the Network for Advancement of Transfusion Alternatives (NATA) guidelines 1 and supported by the Association of Anaesthetists of Great Britain and Ireland (AAGBI) guidelines 1.

Key Considerations

• The patient’s target Hb before elective surgery should be within the normal range, according to the World Health Organization criteria 1
• Further laboratory testing should be performed to evaluate anaemia for nutritional deficiencies, chronic renal insufficiency, and/or chronic inflammatory disease 1
• Nutritional deficiencies should be treated, and erythropoiesis-stimulating agents may be used for anaemic patients in whom nutritional deficiencies have been ruled out, corrected, or both 1

Recommendations for Ana Lab Ordering

• All patients should have their haemoglobin concentration (Hb) measured before listing for major elective surgery 1
• Patients who are anaemic by the World Health Organization definition should be investigated before elective surgery and treated appropriately, and elective non-urgent surgery other than caesarean section should be delayed 1
• The use of intra-operative cell salvage and tranexamic acid administration should be considered in all non-obstetric patients where blood loss > 500 ml is possible and in traumatic and obstetric major haemorrhage 1

Prioritizing Patient Outcomes

The primary goal of ordering ana lab is to improve patient outcomes by detecting and managing preoperative anaemia, which can reduce the risk of blood transfusion, perioperative morbidity, and mortality. By following the recommended guidelines and considering the patient's individual needs, healthcare providers can prioritize morbidity, mortality, and quality of life as the primary outcomes.

From the Research

When to Order Ana Lab

• The decision to order ana lab tests should be made on a case-by-case basis to avoid inconveniencing the patient, delaying the surgical procedure, and driving up the cost of surgical treatment 2.
• Pre-operative laboratory investigations can help identify body abnormalities that cannot be detected through clinical evaluation alone, and can substantially increase the costs 2.
• The incidence of tests with abnormal results can be high, and laboratory tests can help ensure the patient is in an ideal preoperative condition 2.
• A multidisciplinary, multimodal, individualised strategy, collectively termed 'patient blood management', may reduce or eliminate allogeneic blood transfusion and improve outcomes, and pre-operative haematological assessment is an important part of this approach 3.
• Pre-operative testing may include determining the ABO group and Rh type and screening for atypical alloantibodies in blood samples, and the expiration date of the preoperative blood sample for blood typing and screening can be extended to 30 days 4.
• Complete Blood Count (CBC) can be useful in assessing cardiovascular and metabolic diseases in clinical settings, and can predict the risk of cancer, cardiovascular disease, arteriosclerosis, type 2 diabetes, and metabolic syndrome 5.
• In patients with diabetes, antiplatelet and anticoagulation therapy can be important in preventing thrombotic events, and the risk-benefit balance of these therapies should be carefully considered 6.

Key Considerations

• The patient's medical history and current condition should be taken into account when deciding which ana lab tests to order 2.
• The potential benefits and risks of each test should be weighed, and the tests should be ordered only when necessary 2.
• The results of ana lab tests should be interpreted in the context of the patient's overall clinical picture, and should be used to inform anaesthetic decision-making 2.