Principles of perioperative care

Clinical history

Clinical history should include medical and surgical history, medications and allergies, as well as information related to the medical condition for which the procedure is planned; co-morbidities and factors related to risks of complications; personal or family history or risk factors for thromboembolism; and personal or family history of anaesthetic complications.

The preoperative medical assessment should also include questions on chest pain or breathlessness, history of angina or heart attack, stroke, epilepsy, neck or jaw problems, kidney liver or thyroid disease, asthma, diabetes, bronchitis and other respiratory conditions.

Clinical examination

Preoperative screening of medical conditions or risk factors should be followed by clinical examination, including cardiovascular and respiratory examination to evaluate fitness for anaesthesia. A complete pelvic examination should be performed preoperatively. A pelvic examination is often repeated under anaesthesia to confirm the previous findings.

Investigations

Preoperative blood investigations include full blood count; urea and electrolytes for screening for renal disease in patients with hypertension or diabetes and in women on diuretics; liver function tests for patients with a history of alcohol abuse or liver disease; and group and screen prior to procedures with risk of bleeding and cross-match if heavy bleeding is anticipated or antibodies are present. The availability of a cell saver should be considered if significant bleeding is anticipated.

Blood glucose tests and HbA1C are indicated to screen for diabetes and assess diabetic control. Routine coagulation screening is not necessary unless the patient has a known bleeding disorder or has been on medication that causes anticoagulation. A chest X-ray is indicated for patients with chest disease. A pregnancy test should be undertaken in all women of reproductive age. An electrocardiogram (ECG) is mandatory preoperatively in patients with cardiac disease, hypertension and advanced age.

Medications

Aspirin should be discontinued 7–10 days before surgery, as it inhibits platelet cyclooxygenase irreversibly, so platelet aggregation studies can be abnormal for up to 10 days. Non-steroidal anti-inflammatory drugs (NSAIDs) cause inhibition of cyclooxygenase, which is reversible.

Clopidogrel bisulphate, an oral antiplatelet agent, causes a dose-dependent inhibition of platelet aggregation and takes about 5 days after discontinuation for bleeding time to return to normal. Patients on oral anticoagulants need to be converted to low-molecular-weight heparin (LMWH). Management of these patients should be undertaken by a multidisciplinary team involving haematologists.

Women with risk factors for venous thromboembolism (VTE) should receive LMWH thromboprophylaxis. The combined oral contraceptive pill should be stopped 4–6 weeks prior to major surgery to minimize the risk of VTE, and alternative contraception should be offered. The progesterone-only pill is not known to increase the risk of VTE. Although hormone replacement therapy is a risk factor for postoperative VTE, this risk is small and it is not necessary to stop prior to surgery. On the day of surgery, patients should be advised which of their medications they should take.

Management of anaemia

Iron-deficiency anaemia should be treated with iron therapy before surgery. Recombinant erythropoietin (Epo) can be used to increase haemoglobin concentrations. To be effective, iron stores must be adequate, and iron should be given before or concurrently with Epo. When significant blood loss is anticipated in women who will not accept blood products, Epo may be used to increase the haemoglobin concentration preoperatively.

Gonadotropin-releasing hormone agonists may be used preoperatively to stop abnormal uterine bleeding and increase haemoglobin concentrations.

Autologous blood donation avoids the risks of HIV or hepatitis infection and transfusion reactions.

Antibiotic prophylaxis

Antibiotic prophylaxis should be administered intravenously before the start of the procedure. In prolonged procedures or where the estimated blood loss is excessive, additional doses should be administered. Co-amoxiclav or cephalosporins with metronidazole are the commonly used antibiotics. For patients with known hypersensitivity, alternative broad-spectrum agents include combinations of clindamycin with gentamicin, ciprofloxacin or aztreonam; metronidazole with gentamicin; or metronidazole with ciprofloxacin. In patients with a known history of methicillin-resistant Staphylococcus aureus (MRSA) infection or colonization, addition of vancomycin is recommended. Preoperative screening is recommended in women at risk for sexually transmitted infections, and antibiotic cover for Chlamydia with doxycycline or azithromycin should be given.

Skin preparation with an antiseptic and a sterile technique reduces the risks of infection. Minor procedures do not require antibiotic prophylaxis.