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Surgical preoperative assessment What to do and why As a newly qualified doctor responsible for preoperative assessment (often called pre-clerking), you are in charge of one of the most important steps in a patient’s pathway to surgery. Although it is often seen as a chore, getting this right is vital for avoiding potentially life threatening perioperative complications, cancelled operations, and wasted theatre resources (box 1). Despite this importance, few medical students receive dedicated teaching on preoperative assessment.
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Why patients are assessed Formalised preoperative assessment before admission for elective surgery is now common. Traditionally, patients were admitted the day before surgery for clerking, diagnostic tests, and any specific preparation—for example, bowel preparation or heparin administration.
This meant an unnecessary night’s stay, which was expensive for hospitals and inconvenient for patients. Last minute problems identified on admission often resulted in cancellation on the day of surgery. Most commonly this was caused by pre-existing medical conditions—for example, poorly controlled chronic obstructive pulmonary disease—or new ones discovered at clerking and requiring further investigation—for example, unstable angina. Preoperative assessment ensures the patient’s condition is optimised for surgery, and potential complications are planned for. It is now widely used to improve patient care and safety while avoiding wasted hospital resources. Assessment usually takes place in focused preoperative clinics, run jointly by specialist nurses, junior doctors, and anaesthetists. This will typically take place one to two weeks before surgery. Some
Box 1: Case scenarios: the importance of getting it right • Mrs S attended a preoperative assessment before her right hemicolectomy. Unfortunately, her social history missed that she was the main carer for her disabled husband. Postoperatively, her discharge was delayed until she was fully recovered and able to return to caring for him. • Mr A attended a preoperative assessment before radical cystoprostatectomy, and a thorough smoking and alcohol history was taken. Postoperatively, he was admitted to the surgical high dependency unit, where he developed agitation and shakiness. He underwent an extensive septic screen, and the surgeons were called in to rule out complications. When the anaesthetic house officer looked back at his preoperative clerking, he realised Mr A consumed up to 56 units of red wine a week and had alcohol withdrawal. This situation could have been avoided if his alcohol history had been highlighted and appropriate medication prescribed. • Mr N attended a preoperative assessment before his anterior resection. After a thorough history and examination, specific note was made of known comorbidities (type 2 diabetes, hypertension, and hypercholesterolaemia), a 75 pack year history, and three pillow orthopnoea. No further action was taken, however. Postoperatively, Mr N developed type 2 respiratory failure and congestive cardiac failure. Preoperative pulmonary function tests, an echocardiogram, and respiratory and cardiology specialist opinions might have optimised his condition before surgery and avoided this outcome.
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hospitals have trained nurses completing preoperative assessment proformas. If an abnormality is found, the team’s junior doctors are asked to review the patient’s fitness to undergo surgery. A thorough preoperative assessment should assist both the patient and the hospital. Box 2 lists the key benefits for patients. Is my patient fit for surgery? Fitness for surgery depends largely on two factors: the grade of surgery the patient is about to undergo and their health status. For the grading, the National Institute for Health and Clinical Excellence (NICE) in the United Kingdom has created a simple system; box 3 shows examples. To assess a patient’s health status, you need to take a standard history with emphasis on certain points. The purpose is not to make a diagnosis or elicit a detailed history, but to focus on health issues relevant to anaesthesia and postoperative stay (box 4).The preoperative clinic is a good place to learn about conditions you may not have encountered, as patients already have a diagnosis—ideal for examination revision. It is also an excellent opportunity to develop a rapport with the patient, who will become one of your inpatients in the weeks to come. It is important to document any history of surgery and previous anaesthetics. A good social history will enable early occupational therapy and social service input, thus minimising hospital stay through discharge planning. You should check if it is appropriate for the patient to be admitted on the day of surgery—are they older or do they have far to travel—and establish if the patient has home help measures in place for discharge or will require some. Box 2: Advantages of preoperative assessment1‑4 • Patient assessment before surgery gives time to optimise medical conditions • Investigations performed in a timely manner before anaesthetic and surgery • Informed consent taken with discussion of risks and benefits and time for questions • Opportunity to meet other team members— for example, stoma nurse, dietitian, or physiotherapist • Self help measures to improve surgical outcome can be promoted—for example, stopping smoking • Patient can be familiarised with the hospital, ward, and staff who will be caring for them • Allows patient’s fears or anxiety regarding their forthcoming operation to be dealt with
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Box 3: NICE surgery grading scale5 • Grade 1 (minor)—for example, excision of skin lesions, drainage of breast abscess • Grade 2 (intermediate)—for example, primary repair of inguinal hernia, excision of varicose veins of the leg, adenotonsillectomy, knee arthroscopy • Grade 3 (major)—for example, total abdominal hysterectomy, endoscopic resection of prostate, lumbar discectomy, thyroidectomy • Grade 4 (major+)—for example, total joint replacement, lung operations, colonic resection, radical neck dissection, neurosurgery, cardiovascular surgery
Highlighting potential problems A smoking history may highlight potential cardiorespiratory problems, while documenting alcohol intake may identify risk of alcohol withdrawal. As with a normal history, undertake a systems review and note current medications and allergies. An allergy check is particularly important as this cannot be checked when the patient is under anaesthetic and may have an impact on surgery. For example, an iodine allergy will require a non-iodine based skin preparation, and a latex allergy will influence choice of surgical gloves. Essential systems to examine include the cardiorespiratory system and the system to be operated on. You should note abnormalities in heart sounds, breath sounds, and any signs of heart failure or respiratory distress. Check whether these are new developments, not just with the patient but also in the notes or with the general practitioner. Based on your findings, establish which American Society of Anesthesiologists (ASA) grade the patient falls into (box 5). This provides an approximate overall assessment of a patient’s “fitness” for surgery.6 The higher the grade, the greater the risk. Finally, it is important to confirm whether surgery is still required. Find out if there have been any substantial changes in signs and symptoms. If there are, you should discuss the case with the consultant surgeon. Always ask if you are unsure. Investigations In the UK, guidelines from NICE classify investigations required preoperatively by grade of surgery and ASA classification of the patient.5 Use this as guidance if your hospital or surgical team does not have its own protocol or preferences. Similarly, in other countries, surgical or anaesthetic organisations often have national guidelines you can refer to (box 6). The following provides an overview of which investigations you might want to consider and why. Blood tests Most procedures under general anaesthetic will require baseline blood tests, including 30 | student.bmj.com
Box 4: Common conditions that can affect perioperative care • Ischaemic heart disease—is this patient at risk of a perioperative myocardial infarction? • Congestive cardiac failure—could this patient develop perioperative pulmonary oedema? • Chronic respiratory disease—how will this affect the anaesthetic and extubation? • Diabetes—will this patient require a sliding scale for insulin control? • Liver or kidney dysfunction—how will fluid balance and medication dosage be affected in the perioperative period?
a full blood count, urea and electrolytes, liver function tests, and a coagulation screen (if the patient is on anticoagulants or has liver dysfunction). Dependent on the operation and the hospital protocol, the patient’s blood may need to be grouped and saved or cross matched for transfusion. Electrocardiogram Hospital protocol may require a baseline electrocardiogram, although this is more important in higher ASA grades, known cardiovascular disease, and older patients. It could be a key comparison in the event of any adverse cardiac events postoperatively. Chest radiograph The Royal College of Radiologists says that a routine chest radiograph is not required unless the anaesthetist specifically requests one or the patient is likely to need the high dependency unit postoperatively.11 In practice, high ASA grade patients undergoing major surgery will require one, as will those with established chest disease or those undergoing cardiothoracic surgery. Echocardiogram NICE guidelines do not cover the indications for echocardiography as this investigation is considered to be part of the routine cardiovascular care of a patient. In practice, if you have noted a newly documented heart murmur, new or worsening evidence of heart failure with no echocardiogram in the past five years, or previous history of myocardial infarction then it may be prudent to order an echocardiogram after discussion with the anaesthetist or a cardiologist.12 Arterial blood gases and pulmonary function tests In patients with symptoms of advanced chronic respiratory disease with no formal diagnosis and in those with low oxygen saturations on routine preoperative observations, a baseline arterial blood gas is useful. In those undergoing lung surgery or with severe respiratory disease, formal pulmonary function tests may be required.
Box 5: American Society of Anesthesiologists physical classification system ASA I—normal healthy patient ASA II—patient with mild systemic disease ASA III—patient with severe systemic disease ASA IV—patient with severe systemic disease that is a constant threat to life ASA V—moribund patient who is not expected to survive without the operation The suffix E is given when the procedure is being performed as an emergency
Urinalysis Urinalysis is routine in urological surgery and to exclude urinary tract infections in patients who are to receive prostheses (for example, a joint or heart valve). It gives you or the patient’s general practitioner time to treat infections before surgery. MRSA screening Establishing meticillin resistant Staphylococcus aureus (MRSA) status in a patient is important for avoiding cross infection in hospital. An eradication regimen can be initiated if the patient is a carrier. Pregnancy test A pregnancy test is appropriate for all women of child bearing age in whom pregnancy is possible. Special situations Some patients may need special investigations or certain regimens may need to be set up on admission—you should foresee and arrange this. Again, there could be local hospital guidelines. Anticoagulants Patients taking warfarin will most commonly need to stop at least five days before surgery and start subcutaneous low molecular weight heparin, depending on the indication for warfarin treatment. They will also need to have their international normalised ratio checked before surgery to ensure this is within a safe range, depending on the surgeon’s preferences. In some circumstances, such as the presence of mechanical prosthetic heart valves, patients may need to be started on an intravenous heparin infusion with regular monitoring to ensure the time without therapeutic anticoagulation is minimised. Check with a haematologist. Patients taking specific antiplatelets (for example, clopidogrel) require special care. There is a high risk of adverse events if treatment is stopped suddenly, particularly in the presence of a drug eluting cardiac stent.13 It is best to discuss these cases with the anaesthetist and a cardiologist. Patients taking aspirin are commonly student bmj | volume 20 | january 2012
Box 6: Worldwide guidelines on perioperative investigations • Canada: Guidelines to the Practice of Anesthesia. Revised edition. Canadian Anesthesiologists’ Society, 20117 • India: Guidelines for Common Surgical Interventions in the Elderly. World Health Organization, 20088 • United States: Pre-operative Evaluation. Institute for Clinical Systems Improvement, 20109 • United States: ACC/AHA Guidelines on Perioperative Cardiovascular Evaluation and Care for Noncardiac Surgery, 200710
Box 7: Worldwide guidance on consent for surgery
asked to stop up to five days before surgery; however, there is great variation depending on the procedure, so check with the operating surgeon. Diabetes Diabetic patients requiring insulin will usually start on a sliding scale insulin regimen over the perioperative period to avoid swings in blood glucose and electrolytes. Patients with diabetes should ideally be put first on the operating list to minimise the fasting period, so ensure that the theatre coordinator knows about this and nursing staff undertake regular glucose monitoring. Alcohol dependence If you suspect that a patient may experience alcohol withdrawal during their stay in hospital, consider prescribing appropriate drugs to reduce the risk. The patient might also require a course of parenteral thiamine. Steroids Patients with steroid deficiencies (for example, Addison’s disease) requiring replacement therapy or those otherwise on the equivalent of ≥10 mg of prednisolone in the three months preceding surgery will need supplemental cover for surgical stress during the perioperative period. How much they receive depends on the grade of surgery. The initial infusion is started at induction of anaesthesia, so you will need to ensure that the anaesthetist is aware. Postoperative regimens are variable and may be started by the anaesthetist, or you should consult an endocrinologist.14 student bmj | volume 20 | january 2012
Sickle cell testing Sickle cell crises may be triggered during the perioperative period. It is important to test for sickle cell disease in patients, depending on their country of origin or family history of sickle cell trait or disease. Specialist haematology advice may be required. A thorough review Always check local guidelines for specific operations. Even if there aren’t any, your team may have certain preferences so ask them. In addition to the above, patients may need bowel preparation, specialist radiological imaging, specific blood products, stoma siting, surgical equipment, or frozen section histopathology booking for the day of their surgery. Ensure that arrangements are in place for this. Don’t forget to complete a drug chart. Ensure that all the patient’s medications have been prescribed (check with the general practitioner if necessary). You may need to complete a venous thromboembolism assessment in addition to prescribing postoperative venous thromboembolism prophylaxis. Prophylactic antibiotics may also be required, so check local protocol and surgeon preferences. Ensure that the patient is correctly booked on the operating list on the day they are supposed to undergo surgery. All this planning will save you running around on the morning of the procedure. Finally, be aware of the rules surrounding patient consent. In the UK current General Medical Council guidelines state that junior doctors are allowed to take consent if they are suitably trained and qualified to do so,
• Canada: Consent—A Guide for Canadian Physicians. Canadian Medical Protective Association, 200616 • Australia: Consent to Treatment Policy for the Western Australian Health System. 2nd ed. Office of Safety and Quality in Healthcare, Western Australian Department of Health, East Perth17 • United States: Informed Consent. American Medical Association18
have sufficient knowledge of the proposed investigation or treatment, and understand the associated risks.15 Local guidelines may surpass this, requiring the operating surgeon or someone able to perform the procedure to take consent. Check this, as your discussion with the patient could be invalid. Consent rules vary from country to country, so be aware of local regulations where you practise (box 7). Pravisha Ravindra foundation year 2 doctor, trauma and orthopaedics, Nottingham University Hospitals, Nottingham, UK Edward Fitzgerald specialist registrar, general surgery, Royal Marsden Hospital NHS Foundation Trust, London, UK
[email protected] Competing interests: None declared. Patient consent not required (patient anonymised, dead, or hypothetical). Provenance and peer review: Not commissioned; externally peer reviewed. References are in the version on student.bmj.com Cite this as: Student BMJ 2012;20:d7816
Further reading Garcia-Miguel FJ, Serrano-Aguilar PG, LopezBastida J. Preoperative assessment. Lancet 2003;362:1749-57.19 National Institute for Health and Clinical Excellence. Pre-operative tests: the use of routine preoperative tests for elective surgery. NICE, 2003. www.nice.org.uk/nicemedia/ live/10920/29090/29090.pdf Association of Anaesthetists of Great Britain and Ireland. Pre-operative assessment: the role of the anaesthetist. AAGBI, 2001. www. aagbi.org/publications/guidelines/docs/ preoperativeass01.pdf General Medical Council. Consent: patients and doctors making decisions together. GMC, 2008. www.gmc-uk.org/static/documents/ content/Consent_0510.pdf
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