Patients who are scheduled for a surgical procedure, whether in an outpatient or inpatient setting, are often evaluated by the anesthesiology team to prepare for anesthesia care and may be referred by the surgical team to an internist for medical evaluation prior to surgery. The goal of preoperative medical evaluation is to minimize risk of perioperative complications by identifying medical abnormalities and evaluating the risks posed by known comorbidities. This assessment is used to determine whether additional preoperative preparation and perioperative monitoring and management are needed. In some cases, elective procedures should be delayed so that certain underlying disorders (eg, hypertension, diabetes, hematologic abnormalities) can be optimally controlled. In other cases, if patients are deemed high risk for major surgery, the plan for the surgical approach and anesthesia care may be adjusted preoperatively to reduce risk (eg, using a less invasive intervention).
A thorough preoperative medical evaluation is typically done by a general internist or specialists in areas relevant to a patient's comorbidities (eg, cardiologists, pulmonologists). Such consultants may help manage preexisting disease (eg, diabetes) and help prevent and treat perioperative and postoperative complications (eg, cardiac, pulmonary, infectious). Psychiatric consultation is occasionally needed to assess capacity or help manage underlying psychiatric problems that can interfere with surgery or recovery.
Older adults may benefit from involvement of an interdisciplinary geriatric team, which may include geriatricians, social workers, psychotherapists, physical medicine and rehabilitation specialists, and other health care professionals (1).
For procedures that are not elective, the acuity and type of proposed operation should be considered as well as the patient's risk with surgery. In addition, if an emergency procedure is required (eg, for intra-abdominal hemorrhage, perforated viscus, necrotizing fasciitis), there is usually not time for a full preoperative evaluation. However, the patient's history should be reviewed as expeditiously as possible, particularly for allergies and to help identify factors that increase risk of emergency surgery (eg, anticoagulant therapy or a bleeding disorder or prior adverse anesthetic reactions).
History
A relevant preoperative history includes all of the following:
Current symptoms suggesting an active cardiopulmonary disorder (eg, cough, chest pain, dyspnea during exertion, ankle swelling) or infection (eg, fever, dysuria)
Risk factors for excessive bleeding (eg, anticoagulant therapy, known bleeding disorder, or history of bleeding excessively with dental procedures, elective surgeries, or childbirth)
Risk factors for thromboembolism
Risk factors for infection
Known disorders that increase risk of complications, particularly hypertension, heart disease, cerebrovascular disease, kidney disease, liver disease, diabetes, asthma, and chronic obstructive pulmonary disease (COPD)
Previous surgery, anesthesia, or both, and any associated complications
Allergies to anesthetic agents or other medications or to materials used during surgical care (eg, latex, adhesives)
Tobacco, alcohol, or illicit drug use
Current prescription and nonprescription medication and supplement use
History of obstructive sleep apnea or excessive snoring
If an indwelling bladder catheter may be needed, patients should be asked about prior urinary retention and prostate surgery.
Physical examination
Physical examination should address areas involved in the planned surgical procedure and also the cardiopulmonary system, as well as evaluation for any signs of ongoing infection (eg, upper respiratory tract, skin).
If spinal anesthesia is likely to be used, patients should be evaluated for scoliosis and other anatomic abnormalities that may complicate lumbar puncture.
Any cognitive dysfunction, especially in older adults who will be given a general anesthetic, should be noted. Preexisting dysfunction may become more apparent postoperatively and, if undetected beforehand, may be misinterpreted as a surgical complication.
Testing
Healthy patients undergoing elective surgery have a low prevalence of undiagnosed disease that would influence perioperative management. Thus, routine preoperative testing should not be done in those without clinical symptoms or significant underlying disease. Such testing is not cost effective and results in false-positive test results, unintended patient anxiety, and delays in surgery.
In symptomatic patients, those with known underlying disease, or those undergoing procedures with a higher risk of significant bleeding or other complications, laboratory evaluation may include the following tests:
Complete blood count (CBC) is usually done. CBC is particularly relevant in patients > 65 years old or in younger patients with significant anticipated blood loss.
Urinalysis (glucose, protein, and cells) is usually done.
Serum electrolytes and creatinine and plasma glucose are measured unless patients are extremely healthy and < 50 years old, the procedure is considered very low risk, and use of nephrotoxic drugs is not expected.
Liver tests are often measured if abnormalities are suspected based on the patient’s history or examination.
Coagulation studies and bleeding time are needed only if patients have a personal or family history of bleeding diathesis.
ECG is done for patients at risk of coronary artery disease (CAD), including all men > 45 and women > 50 years old, and for patients with severe obesity (body mass index ≥ 40 kg/m2) with at least one risk factor for atherosclerotic cardiovascular disease (eg, diabetes, smoking, hypertension, or hyperlipidemia) or poor exercise tolerance (6).
Chest x-ray is done only in patients with symptoms of or risk factors for underlying cardiopulmonary disease.
Pulmonary function testing may be done if patients have a known chronic pulmonary disorder or symptoms or signs of pulmonary disease.
Patients with symptomatic CAD need additional tests (eg, stress testing, coronary angiography) before surgery.
General references
1. Mohanty S, Rosenthal RA, Russell MM, et al: Optimal perioperative management of the geriatric patient: a best practices guideline from the American College of Surgeons NSQIP and the American Geriatrics Society. J Am Coll Surg 222(5):930-947, 2016. doi:10.1016/j.jamcollsurg.2015.12.026
2. Fleisher LA, Fleischmann KE, Auerbach AD, et al: ACC/AHA 2014 guideline on perioperative cardiovascular evaluation and management of patients undergoing noncardiac surgery (executive summary); a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation 130:2215-2245, 2014. doi: 10.1161/CIR.0000000000000105
3. O'Neill F, Carter E, Pink N, et al: Routine preoperative tests for elective surgery: summary of updated NICE guidance. BMJ 354:i3292, 2016. doi:10.1136/bmj.i3292
4. Halvorsen S, Mehilli J, Cassese S, et al: 2022 ESC Guidelines on cardiovascular assessment and management of patients undergoing non-cardiac surgery [published correction appears in Eur Heart J. 2023 Nov 7;44(42):4421]. Eur Heart J. 2022;43(39):3826-3924. doi:10.1093/eurheartj/ehac270
5. ACOG Committee Opinion No. 775: Nonobstetric Surgery During Pregnancy. Obstet Gynecol. 2019;133(4):e285-e286. doi:10.1097/AOG.0000000000003174
6. Poirier P, Alpert MA, Fleisher LA, et al: Cardiovascular evaluation and management of severely obese patients undergoing surgery: a science advisory from the American Heart Association. Circulation 120(1):86-95, 2009. doi:10.1161/CIRCULATIONAHA.109.192575
Procedural Risk Factors
Procedural risk is highest with the following:
Heart or lung surgery
Hepatic resection
Intra-abdominal operations that are estimated to require a prolonged operative time or that have a risk of large-volume hemorrhage (eg, Whipple procedure, aortic surgery, retroperitoneal surgery)
Open prostatectomy
Major orthopedic procedures (eg, hip replacement)
Patients undergoing elective surgery, particularly for procedures with a significant risk of hemorrhage, and for patients with reasons to avoid allogeneic transfusion (eg, alloantibodies to red blood cell antigens or religious reasons for refusing blood from other people) may consider banking blood for potential autologous transfusion. The perioperative risk of anemia and possible delay in surgery if time is needed for blood cell counts to normalize should be considered. Autologous donation used to be a more common practice, but its use has decreased with the increasing safety of blood transfusions.
Emergency surgery has a higher risk of morbidity and mortality than the same procedure done electively.
Patient Risk Factors
The contribution of a patient's risk factors to perioperative morbidity and mortality is best estimated by validated quantitative risk calculators. For example, the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) has developed a risk calculator to predict perioperative adverse events (see ACS NSQIP Surgical Risk Calculator). Use of these tools not only allows uniformity in interpreting surgeons' outcomes data but also contributes to better shared decision-making and informed consent for patients and family members (1).
Cardiac risk factors
Cardiac risk factors dramatically increase surgical risk. Perioperative cardiac risk is typically assessed using the American College of Cardiology/American Heart Association's stepwise approach to preoperative cardiac assessment (2). It considers the following independent predictors of cardiac risk:
History of coronary artery disease (CAD)
History of heart failure
History of cerebrovascular disease
Serum creatinine (2.0 mg/dL)
Risk of cardiac complications increases with increasing risk factors:
No risk factors: 0.4% (95% confidence interval 0.1 to 0.8%)
1 risk factor: 1.0% (95% confidence interval 0.5 to 1.4%)
2 risk factors: 2.4% (95% confidence interval 1.3 to 3.5%)
≥ 3 risk factors: 5.4% (95% confidence interval 2.8 to 7.9%)
A high-risk surgical procedure (eg, vascular surgery, open intrathoracic or intraperitoneal procedure) also independently predicts a high cardiac perioperative risk.
Patients with active cardiac symptoms (eg, of heart failure or unstable angina) have a particularly high perioperative risk. Patients with unstable angina have an increased risk of perioperative myocardial infarction (3). In patients with stable angina, risk is proportional to their degree of exercise tolerance. Patients with active cardiac symptoms thus require thorough evaluation. For example, the cause of heart failure should be determined so that perioperative cardiac monitoring and treatment can be optimized before elective surgery. Other cardiac testing, such as stress echocardiography or even angiography, should be considered if there is evidence of reversible cardiac ischemia on preoperative evaluation.
Preoperative care should aim to control active disorders (eg, heart failure, diabetes) using standard treatments. Also, measures should be taken to minimize perioperative tachycardia, which can worsen heart failure and increase risk of myocardial infarction; for example, pain control should be optimized and beta-blocker therapy should be considered, especially if patients are already taking beta-blockers. Coronary revascularization should be considered for patients with unstable angina. If a heart disorder cannot be corrected before surgery or if a patient is at high risk of cardiac complications, intraoperative and sometimes preoperative monitoring with pulmonary artery catheterization may be advised. Sometimes the cardiac risk outweighs the benefit of surgery. In such cases, a less invasive procedure may provide or serve as a bridge to definitive treatment (eg, tube cholecystostomy for cholecystitis) and decrease morbidity and mortality.
History of ischemic stroke
Patients with a history of ischemic stroke are at a higher risk of perioperative stroke, and the ideal timing for surgery after a stroke is uncertain. A study based on Medicare data included almost 6 million patients and found that a history of stroke within 30 days before surgery compared to no prior stroke was associated with an 8-fold risk of postoperative ischemic stroke; between 60 to 90 days after a stroke, the risk of recurrent perioperative stroke decreased, but remained elevated (4). Therefore, decisions regarding timing of surgery in patients with a history of ischemic stroke should consider both the risk of recurrent stroke and the potential negative consequences of delaying surgery. To minimize risk of recurrence, elective surgery should be deferred for a minimum of 3 months after a stroke, and ideally up to 9 months if possible.
Infections
Incidental bacterial infections discovered preoperatively should be treated with antibiotics. However, infections should not delay surgery unless prosthetic material is being implanted; in such cases, surgery should be postponed until the infection is controlled or eliminated.
Patients with respiratory infections should be treated and have evidence that the infection has resolved before receiving inhalational anesthesia.
Viral infections with or without fever should be resolved before elective surgery is done, especially if a general anesthetic is going to be used.
For SARS-CoV-2, the American Society of Anesthesiologists (ASA) and the Anesthesia Patient Safety Foundation (APSF) recommends against universal preoperative screening in asymptomatic patients; they recommend COVID-19 testing for patients with symptoms and also that each facility implement robust infection control measures and conduct targeted screening based on individual patient exposure, local incidence of COVID‐19, and facility physical layout (see APSF: ASA and APSF Statement on Perioperative Testing for the COVID-19 Virus and ASA and APSF Updated Statement on Perioperative Testing for SARS-CoV-2 in the Asymptomatic Patient).
Fluid and electrolyte imbalances
Fluid and electrolyte imbalances should be corrected before surgery. Hypokalemia, hyperkalemia, hypocalcemia, and hypomagnesemia must be corrected before general anesthesia to decrease risk of potentially lethal cardiac arrhythmias. Dehydration and hypovolemia should be treated with IV fluids before general anesthesia to prevent severe hypotension on induction—blood pressure tends to fall when general anesthesia is induced.
Nutritional disorders
Undernutrition and obesity increase the risk of postoperative complications in adults. Nutritional status is assessed preoperatively using history, physical examination, and laboratory tests.
Severe nutritional risk factors include the following:
A body mass index < 18.5 kg/m2 or a history of unintentional weight loss > 10% of body weight over 6 months or 5% over 1 month
Suggestive physical examination findings (eg, muscle wasting, signs of specific nutritional deficiencies)
It is important to ask whether weight loss was intentional, because unintentional weight loss may reflect a catabolic state refractory to nutritional repletion, suggesting serious underlying pathology such as cancer.
undernutrition; it should be measured preoperatively in patients who may be undernourished. Values <5). In some cases, surgery can be delayed so patients can receive nutritional support, sometimes for several weeks (eg, in chronically undernourished patients, to help prevent the refeeding syndrome).
Severe obesity (body mass index ≥ 40 kg/m2) increases perioperative mortality risk because such patients have increased risk of cardiac and pulmonary disorders (eg, hypertension, pulmonary hypertension, left ventricular hypertrophy, heart failure, coronary artery disease, decreased ventilatory reserve). Obesity is an independent risk factor for deep venous thrombosis and pulmonary embolism; preoperative venous thromboembolism prophylaxis is indicated in most patients with obesity. Obesity also increases risk of postoperative wound complications (eg, fat necrosis, infection, dehiscence, and abdominal wall hernias).
Age
Older age is associated with decreased physiologic reserve and greater morbidity if a complication occurs. However, chronic disorders are stronger predictors of increased postoperative morbidity and mortality than age alone. Older age is not an absolute contraindication to surgery.
Various factors contribute to increased risk during the perioperative period in older adults. In a prospective study of 1193 major surgeries in community-living adults age ≥ 65 years (mean 79 years), 1-year mortality rates were significantly higher at age ≥ 80 years (2-fold) and highest at ≥ 90 year (6-fold), compared to adults age 65 to 79 years (6). Mortality was also higher among those categorized as frail compared with nonfrail (28% versus 6%); those with probable dementia compared with no dementia (33% versus 12%); and for nonelective compared with elective surgery (3-fold).
Patient risk factor references
1. Bilimoria KY, Liu Y, Paruch JL, et al: Development and evaluation of the universal ACS NSQIP surgical risk calculator: A decision aid and informed consent tool for patients and surgeons.J Am Coll Surg 217(5):833-42.e423, 2013. doi:10.1016/j.jamcollsurg.2013.07.385
2. Eagle KA, Berger PB, Calkins H, et al: ACC/AHA guideline update for perioperative cardiovascular evaluation for noncardiac surgery--executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1996 Guidelines on Perioperative Cardiovascular Evaluation for Noncardiac Surgery) [published correction appears in J Am Coll Cardiol. 2006 Jun 6;47(11):2356]. J Am Coll Cardiol. 2002;39(3):542-553. doi:10.1016/s0735-1097(01)01788-0
3. Gao L, Chen L, He J, et al: Perioperative Myocardial Injury/Infarction After Non-cardiac Surgery in Elderly Patients. Front Cardiovasc Med. 2022;9:910879. Published 2022 May 19. doi:10.3389/fcvm.2022.910879
4. Glance LG, Benesch CG, Holloway RG, et al: Association of Time Elapsed Since Ischemic Stroke With Risk of Recurrent Stroke in Older Patients Undergoing Elective Nonneurologic, Noncardiac Surgery. JAMA Surg. 2022;157(8):e222236. doi:10.1001/jamasurg.2022.2236
5. Weimann A, Braga M, Harsanyi L, et al: ESPEN guidelines on enteral nutrition: Surgery including organ transplantation. Clin Nutr 25:224–244, 2006. doi: 10.1016/j.clnu.2006.01.015
6. Gill TM, Vander Wyk B, Leo-Summers L, et al: Population-based estimates of 1-year mortality after major surgery among community-living older US adults [published correction appears in JAMA Surg 158(3):331, 2023]. JAMA Surg 157(12):e225155, 2022. doi:10.1001/jamasurg.2022.5155
More Information
The following English-language resource may be useful. Please note that The Manual is not responsible for the content of this resource.
2014 ACC/AHA Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines
