Preoperative tests (planned surgery or procedure under anaesthesia, adult)

• Low-risk procedure, no clue on history or examination: no laboratory tests.

Only depending on the procedure, the patient's condition or treatments

• FBC with plateletsif neededIntermediate- or high-risk procedure, whatever the age: prognostic value and aid to transfusion strategy ^[2]. NICE: routine in major surgery, to be discussed in intermediate surgery if ASA 3-4 with cardiovascular or renal disease ^[3]. Surgery with bleeding risk: see the tab “Haemorrhagic surgery: anaemia and iron deficiency” ^[4].
• Serum creatinine with eGFRif neededIntermediate or major surgery in a patient at renal risk (hypertension, diabetes, polycystic kidney disease, family history of renal failure, long-term NSAIDs or aspirin) ^[2]; NICE: routine if ASA 3-4 in intermediate or major surgery ^[3]. Diabetic patient: measure GFR before the procedure, diabetic nephropathy increasing the risk of perioperative acute kidney injury ^[5].
• Serum electrolytes (treatment altering serum potassium, renal failure)if neededTake current treatments into account ^[3]: diuretic, ACE inhibitor, angiotensin receptor blocker (ARB)… Severe dyskalaemias are among the rare abnormalities that justify screening ^[2].
• HbA1c (diabetic patient, if not measured for 3 months)if neededKnown diabetes, last HbA1c more than 3 months ago ^[3]; attach it to the referral letter to the surgeon ^[3]. In the diabetic patient, the SFAR and the French-speaking Diabetes Society recommend assessing glycaemic control before the procedure with HbA1c and recent capillary glucose readings ^[5].
• ABO and RhD blood groupif neededIntermediate- or high-risk procedure for transfusion or major bleeding: results available before the procedure ^[2]. Antibody screen valid 3 days, 21 days if negative and no transfusion, pregnancy or transplant in the previous 6 months (state this on the prescription) ^[2].
• RAIif neededIntermediate- or high-risk procedure for transfusion or major bleeding: results available before the procedure ^[2]. Antibody screen valid 3 days, 21 days if negative and no transfusion, pregnancy or transplant in the previous 6 months (state this on the prescription) ^[2].
• Serum β-hCG (possibility of pregnancy)if neededWoman of childbearing potential in whom the history does not exclude pregnancy, with her consent; if positive, postpone the procedure if possible ^[2].
• Urine microscopy and cultureif neededUrological surgery (including endoscopic); orthopaedic prosthesis or prolapse or incontinence surgery in a patient at risk of urinary tract infection (symptoms, diabetes, old age, institution, long-term catheter) ^[2].
• Urine dipstick, then urine microscopy and culture if nitrites or leucocytesif neededOrthopaedic prosthesis or prolapse or incontinence surgery in a patient with no risk factor for urinary tract infection ^[2].
• PT, aPTT (see the "Hémostase" tab)if neededLiver disease, malabsorption or malnutrition, haematological disease, anticoagulant, or suggestive bleeding history ^[2].
• ASTif needednon-French guidelineKnown or suspected liver disease: these tests are part of the German minimum, with haemoglobin, platelets, sodium, potassium, creatinine, aPTT and INR ^[6]. For this situation, the SFAR and NICE cite the haemostasis tests ^[2,3].
• Bilirubinif needednon-French guidelineKnown or suspected liver disease: these tests are part of the German minimum, with haemoglobin, platelets, sodium, potassium, creatinine, aPTT and INR ^[6]. For this situation, the SFAR and NICE cite the haemostasis tests ^[2,3].

• First the personal and family bleeding history (questionnaire) and examination.

Only if the history, examination or treatments justify it (citrate tube)

• PT, aPTTif neededLiver disease, malabsorption or malnutrition, haematological disease, anticoagulant treatment, suggestive bleeding history; baseline aPTT if unfractionated heparin is planned after the procedure ^[2].
• FBC (platelets)if neededSame situations; baseline count before heparin treatment ^[2].

• Normal pregnancy, nothing abnormal on history or examination: no haemostasis tests, even before an epidural.
• Antibody screen (less than 3 days old)if neededPlanned caesarean section, or situation at risk of haemorrhage (history of postpartum haemorrhage, HELLP, placental abruption, fetal death, abnormal placental insertion, twin pregnancy, scarred uterus, chorioamnionitis, known haemostasis disorder) ^[2].

• As early as possible after the decision to operate (ideally at least one month before), to leave time for correction.

Laboratory tests

• FBC
• Serum ferritinif neededIn preoperative anaemia (haemoglobin < 13 g/dL in men and women alike), routine iron studies: ferritin and transferrin saturation ^[4].
• Transferrin saturationif neededIn preoperative anaemia (haemoglobin < 13 g/dL in men and women alike), routine iron studies: ferritin and transferrin saturation ^[4].
• Folateif neededAnaemia without iron deficiency with MCV > 100 fL: look for folate or vitamin B12 deficiency ^[4].
• Vitamin B12 (anaemia without iron deficiency, MCV > 100 fL)if neededAnaemia without iron deficiency with MCV > 100 fL: look for folate or vitamin B12 deficiency ^[4].

About 4 weeks after the procedure

• FBC
• Serum ferritin
• Transferrin saturation