Perioperative Management of the Knee or Hip Joint Replacement Patient

Laura Kosseim

Atul F. Kamath

Craig L. Israelite

PREOPERATIVE RISK ASSESSMENT

When asked to perform a preoperative risk assessment, the primary care physician’s role is to ensure that the patient’s general health can withstand the rigors of surgery and the postoperative period. A thorough history and physical, along with routine labs (complete blood count [CBC], basic metabolic panel, prothrombin time/partial thromboplastin time (PT/PTT), and type and screen) and an electrocardiogram, usually provide all the information needed to perform a preoperative risk assessment. The preoperative evaluation can also be a time to make recommendations for medication adjustments, lifestyle changes, or future testing that can impact a patient’s overall health. The information obtained from the preoperative evaluation is invaluable to the surgery and anesthesiology teams caring for a patient and should be communicated to them well in advance of the surgery date. More appropriate than a simple statement “cleared for surgery,” the preoperative evaluation letter should include an up-to-date medication list and medical problem list and identify all the areas that can increase a patient’s surgical risk as well as suggestions for attenuating that risk if appropriate. The American Society of Anesthesiologists (ASA) classification helps guide general risk stratification (see Table 64-1). Common medical issues that can affect surgical risk are addressed below.

Cardiac

A review of cardiac risk assessment has been well studied and described elsewhere. The guideline from the American College of Cardiology/American Heart Association has a clear algorithm1 that should be followed for all patients undergoing surgery (Fig. 64-1; Table 64-2). In summary, both the patient’s risk and the surgical risk are assessed and weighed. The patient’s risk factors are determined by the history of coronary disease, angina, valvular disease, arrhythmia, diabetes, hypertension, renal disease, and smoking. These risk factors, in addition to a patient’s functional capacity, help to determine the patient’s cardiac risk. Even a patient at significant cardiac risk can tolerate a very low-risk surgery, such as cataract surgery, without further cardiac testing, but a moderate- or highrisk surgery may warrant further evaluation. Routine cardiac stress testing before all surgeries is not an appropriate use of resources. Patients who have exercise tolerance of greater than the equivalent of 4 metabolic equivalents of task of work, without shortness of breath or chest pain, have essentially performed their own stress test (Fig 64-2).

TABLE 64-1 The ASA Physical Status Classification of General Risk

ASA physical status 1—A normal healthy patient

ASA physical status 2—A patient with mild systemic disease

ASA physical status 3—A patient with severe systemic disease

ASA physical status 4—A patient with severe systemic disease that is a constant threat to life

ASA physical status 5—A moribund patient who is not expected to survive without the operation

ASA physical status 6—A declared brain-dead patient whose organs are being removed for donor purposes

Reprinted with permission from American Society of Anesthesiologists. Copyright © 1995-2012. American Society of Anesthesiologists (ASA), All Rights Reserved. Available: http://www.asahq.org/For-Members/Clinical-Information/ASA-Physical-Status-Classification-System.aspx. A copy of the full text can be obtained from ASA, 520 N. Northwest Highway, Park Ridge, Illinois 60068-2573.

Pulmonary

The American College of Physicians guidelines for preoperative pulmonary assessment include the following recommendations²:

1. All patients undergoing noncardiothoracic surgery should be evaluated for the presence of the following risk factors: chronic obstructive pulmonary disease, age older than 60 years, ASA class II or greater (see Table 64-1), functionally dependent, and congestive heart failure.

2. All patients who are found to be at higher risk for postoperative pulmonary complications should receive the following postoperative procedures in order to reduce postoperative pulmonary complications: (a) deep breathing exercises or incentive spirometry and (b) selective use of a nasogastric tube (as needed for postoperative nausea or vomiting, inability to tolerate oral intake, or symptomatic abdominal distention).

3. Preoperative spirometry and chest radiography should not be used routinely for predicting risk for postoperative pulmonary complications.

For patients felt to be at higher risk of pulmonary complications, the anesthesiologist may consider avoiding general anesthesia, as this can almost double the risk of pulmonary complications.

FIGURE 64-1. ACC/AHA 2007 Guidelines on perioperative cardiovascular evaluation and care for noncardiac surgery. (Reprinted with permission from American Heart Association, Inc. Available online: http://circ.ahajournals.org/content/116/17/e418/F2.expansion.html.)

*See Table 64-2 for active clinical conditions.

†See Class III recommendations for non-invasive stress testing in the full text guideline.

‡See Figure 64-2 for estimated MET level equivalent.

§Noninvasive testing may be considered before surgery in speicific patients wtih risk factors if it will change management.

||Clinical risk factors include ischemic heart disease, compensated or prior heart failure, diabetes mellitus, renal insuficiency, and cerebrovascular disease.

¶Consider perioperative beta blockade for populations in which this has been shown to reduce cardiac morbidity/mortality (see full text guidelines).

There is surprisingly only moderate evidence that current smokers are at increased risk of pulmonary complications and little evidence that advising patients to quit smoking within 8 weeks of surgery significantly decreases that risk. However, the long-term benefits of quitting smoking are clear, and as patients cannot smoke during their hospital stay, helping patients to quit prior to their surgery can make
their hospital course more comfortable and will reinforce the importance of smoking cessation as part of good overall health care.

TABLE 64-2 ACC/AHA 2007 Guidelines on Perioperative Cardiovascular Evaluation and Care for Noncardiac Surgery

Condition	Examples
Unstable coronary syndromes	Unstable or severe angina^a (CCS class III or IV)^b Recent MI^c
Decompensated HF (NYHA functional class IV; worsening or new-onset HF)
Significant arrhythmias	High-grade atrioventricular block Mobitz II atrioventricular block Third-degree atrioventricular heart block Symptomatic ventricular arrhythmias Supraventricular arrhythmias (including atrial fibrillation) with uncontrolled ventricular rate (HR > 100 bpm at rest) Symptomatic bradycardia Newly recognized ventricular tachycardia
Severe valvular disease	Severe aortic stenosis (mean pressure gradient >40 mm Hg, aortic valve area <1.0 cm², or symptomatic) Symptomatic mitral stenosis (progressive dyspnea on exertion, exertional presyncope, or HF)
^aAccording to Campeau L. Letter: grading of angina pectoris. Circulation. 1976;54:522-523. ^bMay include “stable” angina in patients who are unusually sedentary. ^cThe American College of Cardiology National Database Library defines recent MI as more than 7 d but ≤1 mo (within 30 d).
CCS, Canadian Cardiovascular Society; HF, heart failure; HR, heart rate; MI, myocardial infarction; NYHA, New York Heart Association.
Reprinted with permission from ACC/AHA 2007 Guidelines on perioperative cardiovascular evaluation and care for noncardiac surgery: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 2002 Guidelines on Perioperative Cardiovascular Evaluation for Noncardiac Surgery). Copyright© 2012 by American Heart Association, Inc. All rights reserved. Available: http://circ.ahajournals.org/content/116/17/e418/T1.expansion.html.

Obesity and Obstructive Sleep Apnea

Many patients interested in joint replacement surgery also meet the criteria for obesity (body mass index [BMI] > 30) or morbid obesity (BMI > 40). Patients with morbid obesity undergoing joint replacement surgery are at a significantly increased risk for complications, including joint failure, need for revision surgery, superficial and deep infections, and deep vein thrombosis (DVT).³

Obesity also puts patients at risk for obstructive sleep apnea (OSA), which carries risks independent of obesity.

Patients with OSA undergoing hip or knee replacement surgery are at increased risk for complications requiring transfer to an intensive care unit such as cardiac ischemia and respiratory failure as well as longer length of stay. Most complications occur during the first day after surgery but some occur as late as postoperative days 4 or 5.⁴

The American Academy of Anesthesiologists guidelines for patients with known or suspected OSA are as follows:

1. Identify patients at risk based on history and BMI.

2. Improve preoperative status of OSA with the use of continuous positive airway pressure, medications, oral appliances, or weight loss.

3. Avoid general anesthesia if possible.⁵

FIGURE 64-2. Estimated energy requirements for various activities.

Diabetes

Poor diabetes control as measured by an elevated hemoglobin A1c has been shown to be associated with an increased risk of infection and cardiovascular complications in patients undergoing elective hip and knee replacement surgery. Every effort should be made to optimize a patient’s diabetes control prior to elective surgery.

Type 1 diabetics generally have more labile diabetes and should be seen by their endocrinologist for insulin adjustment recommendations perioperatively. For type 2 diabetics, medications need to be adjusted as the patient will be fasting starting the evening prior to surgery. On the morning of the day prior to surgery, metformin should be held and other oral medications can be continued. On the evening prior to surgery, long-acting insulin, such as Lantus, should be reduced by approximately one-third to adjust for the following day.

On the day of surgery, all oral agents and short-acting insulin should be held. If the patient is taking intermediate-acting insulin, such as NPH, in the mornings, this dose should be reduced by half on the day of surgery.⁶

Renal

The presence of chronic kidney disease increases the risk of complications in orthopaedic surgery patients. A glomerular filtration rate should be calculated preoperatively, and all patients with a glomerular filtration rate (GFR) < 60 should be advised to avoid all potentially renally toxic medications and precautions taken if the patient will need intravenous contrast during the hospital stay. If the patient is on hemodialysis, a renal consult should be placed, and ideally the surgery should be scheduled on a nondialysis day.

Liver Disease

Patients with chronic liver disease are at increased risk of complications during surgery. There are two well-validated scoring tools available to help estimate this risk, the Child-Pugh score (Table 64-3) and the Model for End Stage Liver Disease (MELD) score (Table 64-4). As one might expect, operative morbidity and mortality—whether measured by the Child-Pugh or MELD score—increase with increasing severity of liver disease. In general, patients with compensated cirrhosis who have normal synthetic function have a low overall risk, and the risk increases for patients with decompensated cirrhosis.

TABLE 64-3 Child-Pugh Classification of Severity of Liver Disease

	Points Assigned
Parameter	1	2	3
Ascites	Absent	Slight	Moderate
Bilirubin (mg/dL)	<2	2-3	>3
Albumin (g/dL)	>3.5	2.8-3.5	<2.8
Prothrombin time
Seconds over control	1-3	4-6	>6
INR	<1.7	1.8-2.3	>2.3
Encephalopathy	None	Grade 1-2	Grade 3-4
Modified Child-Pugh Classification of the severity of liver disease according to the degree of ascites, the plasma concentrations of bilirubin and albumin, the prothrombin time, and the degree of encephalopathy. A total score of 5-6 is considered grade A (well-compensated disease), 7-9 is grade B (significant functional compromise), and 10-15 is grade C (decompensated disease). These grades correlate with 1- and 2-y survival; grade A: 100% and 65%; grade B: 80% and 60%; and grade C: 45% and 35%. Reprinted with permission from Pugh RN, Murray-Lyon IM, Dawson JL, et al. Transection of the oesophagus for bleeding oesophageal varices. Br J Surg 1973;60(8):646-649. Copyright (c) John Wiley & Sons, Inc.

TABLE 64-4 Meld Score

MELD

3.78 × log_e serum bilirubin (mg/dL)+

11.20 × log_e INR+

9.57 × log_e serum creatinine (mg/dL)+

6.43 (constant for liver disease etiology)

NOTES: If the patient has been dialyzed twice within the last 7 d, then the value for serum creatinine used should be 4.0. Any value <1 is given a value of (i.e., if bilirubin is 0.8, a value of 1.0 is used) to prevent the occurrence of scores below 0 (the natural logarithm of 1 is 0, and any value below 1 would yield a negative result).

Reprinted with permission from Malinchoc M, Kamath PS, Gordon FD, et al. A model to predict poor survival in patients undergoing transjugular intrahepatic portosystemic shunts. Hepatology 2000;31(4):864-871. Copyright (c) John Wiley & Sons, Inc.

The Child-Pugh score, which assigns one to three points according to the presence/absence and levels of each of five simple factors (bilirubin, albumin, prothrombin time/international normalized ratio [INR], ascites, and encephalopathy stage), has been used for decades to assess the severity of liver disease. Mortality rates for patients undergoing elective surgery are 10% for those with Child class A, 30% for those with Child class B, and 76% to 82% for those with Child class C cirrhosis.

The following online calculator (http://www.mayoclinic. org/meld/mayomodel9.html), based on a study by Teh et al.,⁷ is used to calculate 7-day, 30-day, 90-day, 1-year, and 5-year surgical mortality based on the MELD score along with several other variables, including ASA class, INR, and bilirubin. Because knee and hip arthroplasty surgery is generally an elective procedure, these risk calculators can be helpful in counseling your patient who has known liver disease when weighing whether or not to proceed to surgery.

Substance Use

All patients being evaluated for elective surgery should be questioned about use of alcohol, tobacco, prescription pain medicine, and recreational drug use. Alcohol use disorders are associated with complications, including an increased risk of infection, cardiopulmonary complications, increased risk of bleeding from low platelets, and alcohol withdrawal and delirium tremens. Drinking more than five drinks a day is associated with a doubling of mortality rates in surgical patients.

Two commonly used screening tools are the CAGE (cut down, annoyance, guilt, eye-opener) questionnaire and the AUDIT questionnaire (Table 64-5). The CAGE questionnaire is simple to use and remember. Each positive answer counts as one point, and a total of two points or more is considered a positive test and is highly suggestive of alcohol dependence.

The AUDIT questionnaire is a 10-question survey with a total possible score of 40. It is helpful in identifying patients along the spectrum of alcohol use disorders from at-risk drinking to dependence.

TABLE 64-5 Audit Questionnaire: Self-Report Version

PATIENT: Because alcohol use can affect your health and can interfere with certain medications and treatments, it is important that we ask some questions about your use of alcohol. Your answers will remain confidential so please be honest.
Place an X in one box that best describes your answer to each question.
Questions		0	1	2	3	4
1.	How often do you have a drink containing alcohol?	Never	Monthly or less	2-4 times a month	2-3 times a week	4 or more times a week
2.	How many drinks containing alcohol do you have on a typical day when you are drinking?	1 or 2	3 or 4	5 or 6	7-9	10 or more
3.	How often do you have five or more drinks on one occasion?	Never	Less than monthly	Monthly	Weekly	Daily or almost daily
4.	How often during the last year have you found that you were not able to stop drinking once you had started?	Never	Less than monthly	Monthly	Weekly	Daily or almost daily
5.	How often during the last year have you failed to do what was normally expected of you because of drinking?	Never	Less than monthly	Monthly	Weekly	Daily or almost daily
6.	How often during the last year have you needed a first drink in the morning to get yourself going after a heavy drinking session?	Never	Less than monthly	Monthly	Weekly	Daily or almost daily
7.	How often during the last year have you had a feeling of guilt or remorse after drinking?	Never	Less than monthly	Monthly	Weekly	Daily or almost daily
8.	How often during the last year have you been unable to remember what happened the night before because of your drinking?	Never	Less than monthly	Monthly	Weekly	Daily or almost daily
9.	Have you or someone else been injured because of your drinking?	No		Yes, but not in the last year		Yes, during the last year
10.	Has a relative, friend, doctor, or other health care worker been concerned about your drinking or suggested you cut down?	No		Yes, but not in the last year		Yes, during the last year
						Total
From Babor TF, Higgins-Biddle JC, Saunders JB, et al. The alcohol use disorder identification test: guidelines for use in primary care, 2nd ed. World Health Organization; 2001. Available: http://whqlibdoc.who.int/hq/2001/who_msd_msb_01.6a.pdf. Copyright © World Health Organization; 2001.