The outcome of a patient with hip fracture is only partially related to the successful management of the fracture. Many elderly patients have multiple, significant concomitant illnesses. These comorbidities, as well as perioperative complications, significantly impact the patient’s ultimate outcome. This chapter provides a brief synopsis of outcome variables, as well as reviewing the evaluation and management of common coexisting medical conditions, perioperative considerations, postoperative complications, and interventions to avoid postoperative complications.
Outcome Variables
Mortality
A hip fracture is one of the most devastating events that can affect an older person. For the first 3 months following a fracture, women have a 5.75-fold increase, and men a 7.95-fold increase, in mortality. These conditions also have a significant impact on long-term life expectancy. A Danish study found that the mean survival for patients with hip fractures was 6.2 years in comparison to 11.1 years for controls. The median survival was 9.4 years for controls and 3.8 years for hip fracture patients.
The major predictors for mortality for hip fracture patients are the patient’s underlying cognitive, functional, and medical problems ( Table 53-1 ). Dementia has the strongest effect on mortality. Those studies that carefully evaluate mental status found that dementia increases mortality threefold. A study from Mount Sinai Hospital in New York found that patients with advanced dementia and hip fractures have a 6-month mortality of 55% versus a 12% mortality for cognitively intact patients. As dementia is the major reason for nursing home placement, patients living in nursing homes have a much higher mortality than individuals living in the community. A study of 195 residents of a teaching nursing home in Boston found that 77% of their residents with hip fractures die within 1.4 years.
|
Prefracture physical and social function is also a strong predictor of outcome. Immobility prior to the fracture, poor “social function” (proportional to the amount of care patients required prior to their fracture), and a decreased frequency of going out of one’s home prior to fracture are all associated with significantly higher mortality. A cumulated ambulation score was a highly significant predictor for 30-day mortality and postoperative medical complications. In addition to dementia and poor prefracture physical function, congestive heart failure, male gender, deep wound infections, postoperative chest infections, and delirium at the time of hospital admission have all been associated with a higher mortality for hip fracture patients.
Functional Outcome
Patients with hip fractures very often have a significantly reduced physical function. Marottoli and colleagues demonstrated that this decline was closely associated with prefracture physical function. Young and coworkers found that unsteady gait prior to fracture predicted a poor outcome. Multiple studies revealed that patients with a better baseline functional status, such as independent shopping and frequent social contacts outside the home, have a better functional outcome with more complete recovery of their prefracture level of function.
Medical Complications
A study of almost 9000 hip fracture patients found a postoperative complication rate of 19%. Eight percent of patients had cardiac complications and 4%, pulmonary complications. Serious pulmonary complications, however, were as common (2.6%) as serious cardiac complications (2.0%). Gastrointestinal bleeding was seen in 2% of patients, and venous thromboembolism, transient ischemic attacks or cerebrovascular accidents, isolated hypotension, and multiple complications were seen in approximately 1% of patients for each. Patients with multiple complications and renal failure had the highest mortality rates (29%–38%). Patients with any complication had a 34% 1-year mortality as opposed to 12% mortality in patients without complications.
Preoperative Assessment
A preoperative examination and assessment is required to determine the patient’s baseline medical condition, identify decompensated or previously unrecognized conditions, and assess the perioperative risk for a cardiac event. The vast majority of patients with hip fractures are older than the age of 70 years. There are a number of physiologic changes that occur with aging. The older individual has a decreased physiologic reserve. There is a predictable decline with age in pulmonary vital capacity, cardiac output, renal blood flow, glomerular filtration rate, grip strength, and neuromuscular reaction time. There is also a marked increase in the prevalence of diseases with aging. Ninety-percent of patients older than the age of 70 years have at least one comorbid condition. One-third of older patients have at least three or more comorbid conditions. It is the presence of these diseases, more than the changes with age, which increase the risk of surgery for older individuals. The older individual has decreased ability to react to stress. This diminished reserve of the older patient may be less apparent on history and physical examination because of decreased activity caused by joint disease, vascular insufficiency, or other limiting factors.
The two organ systems that are associated with the greatest number of perioperative problems are the cardiovascular and pulmonary systems. Identifying disorders with these two systems as well as others, and optimizing their management, even if this results in a delay in surgery for a day or two, will reduce the chance that complications will mar a successful outcome.
Cardiovascular Assessment
A number of studies have evaluated factors that increase the risk for cardiovascular events in patients undergoing noncardiac surgery. The stress of surgery causes increased cardiac output, increased myocardial oxygen demand, and induces cardiac ischemia. In addition, anesthetic agents can depress the myocardium, cause peripheral vasodilatation, and can induce arrhythmias.
The American Heart Association and the American College of Cardiology guidelines of 2007 simplified their algorithm for perioperative risk stratification and recommendations for preoperative cardiac evaluation. Patients with good prefracture functional status have a low risk of cardiac complications. Functional status is often expressed in metabolic equivalents (METs). One MET is defined as 3.5 mL oxygen (O 2 ) uptake/kg per minute, which is the O 2 uptake in a resting sitting position. Patients who had a prefracture exercise tolerance of four METs or greater, such as the ability to walk a city block or ascend a flight of stairs without significant difficulty, or are low risk by the Revised Cardiac Risk Index (RCRI), can proceed to surgery without any further cardiac evaluation.
Guidelines for perioperative risk stratification for cardiac complications are designed for patients undergoing elective surgery. They are often not helpful in the preoperative evaluation of patients undergoing urgent surgery, such as hip fracture repair. A recent study showed that preoperative cardiac testing did not lead to changes in perioperative orthopaedic or medical management of elderly patients with hip fractures. Patients who did undergo this testing had a significant delay to surgery. There is a very limited role of this testing in patients with hip fractures.
Physicians and surgeons should be aware that patients with unstable angina (new or worsening chest symptoms, including true dyspnea on exertion), decompensated congestive heart failure, arrhythmias, and severe cardiac valvular disease (symptomatic or aortic stenosis with a history of congestive heart failure) have a substantial risk of perioperative cardiac complications. Only in this small subset of patients should hip fracture repair be postponed awaiting further cardiac evaluation and treatment.
The RCRI represents a simple method for determining perioperative risk. Table 53-2 lists the six risk factors. For patients undergoing orthopaedic surgery, patients with none or one RCRI factor do extremely well, with perioperative cardiac complication rates of less than 2%. Even patients with two or more RCRI factors had cardiac complication rates of less than 4% in this study.
| Congestive Heart Failure |
| History of CHF, pulmonary edema, or paroxysmal nocturnal dyspnea, bilateral rales or S 3 , CXR with pulmonary redistribution |
| High-Risk Surgery |
| Intraperitoneal, intrathoracic, suprainguinal vascular |
| History of Ischemic Heart Disease |
| History of MI, history of positive stress test, current chest pain secondary to cardiac etiology, use of nitrates, ECG with pathologic Q waves |
| History of Cerebrovascular Disease |
| TIA or stroke |
| Diabetes Mellitus on Insulin |
| Serum creatinine >2.0 mg/dL |
Cardiac intervention, either with coronary artery bypass grafting (CABG) or percutaneous intervention (percutaneous transluminal coronary angioplasty [PTCA] or stent), performed prior to noncardiac surgery, has not been shown to improve outcomes in patients with stable coronary disease undergoing major vascular surgery. Patients who have had coronary artery revascularization, with either CABG or PTCA or stent within the previous 5 years, however, and have done well since the procedure and are ambulatory, do not have increased cardiac risk and can proceed to surgery without further cardiac evaluation.
There have been a number of studies that have evaluated the benefit of perioperative β-blocker therapy. Initial studies showed a significant reduction in mortality in patients randomized to receive atenolol for noncardiac surgery. A large multicenter trial, done in 190 hospitals in 23 countries, randomized 8351 patients with, or at risk of, atherosclerotic disease, who were undergoing noncardiac surgery, to receive metoprolol or a placebo. Although the treatment group had a lower frequency of myocardial infarction, the patients receiving metoprolol had an increased incidence of stroke, and an overall higher mortality than the placebo group.
There is, thus, a good deal of controversy about the risk-benefit of placing patients on β-blockers prior to surgery. In 2009, the American College of Cardiology made a strong recommendation to continue β-blockers for patients already on these agents. They made a weak recommendation to initiate these drugs in patients undergoing intermediate-risk surgery who have coronary artery disease or more than one clinical risk factor. The European Society of Cardiology recommended that these medications be considered in patients undergoing intermediate-risk surgery.
Although the optimal dose, route, and duration of therapy are not definitively known, patients should be adequately β-blocked at the time of surgery and should receive therapy for at least the hospitalization and ideally until follow-up or 30 days. Many patients will have an indication, such as hypertension or coronary artery disease, to continue β-blocker therapy indefinitely. Patients on β-blockers, but with heart rates greater than 80 beats per minute, will likely benefit from further intravenous medication to lower the heart rate. Those not on β-blockers will need to be loaded intravenously. See Table 53-3 for intravenous and oral β-blocker regimens.
| β-Blockers | Preoperative |
| |
| Postoperative | |
| |
| Clonidine | Preoperative Night |
| |
| Surgical Day | |
|
Clonidine can be used to reduce cardiac risk in patients with contraindication to β-blocker therapy. Wallace and colleagues randomized patients undergoing noncardiac surgery with known coronary artery disease or multiple risk factors, to clonidine or placebo. Perioperative myocardial ischemia was reduced from 31% to 14% and 2-year mortality was reduced from 29% to 15%. See Table 53-3 for a sample clonidine regimen.
Congestive Heart Failure
Congestive heart failure is a major determinant of perioperative complications. Patients should be maintained on their outpatient medications and be monitored for signs and symptoms of pulmonary edema. Appropriate electrolyte and drug levels should be confirmed and corrected as needed.
Patients with symptomatic congestive heart failure, or findings on examination of elevated jugular venous distention, pulmonary crackles, or an S 3 gallop, have increased risk of pulmonary edema and cardiac death. These patients have an independent indication for cardiac evaluation. Routine preoperative transthoracic echocardiography does not add to the clinical evaluation and does not have a routine role in preoperative assessment. Availability of information obtained by the transthoracic echocardiogram did not improve the prognostic information already obtained with the known risk factors from the preoperative evaluation. Patients with new or decompensated congestive heart failure should be investigated, and treatment optimized prior to surgery. The introduction of digitalis preparations in the perioperative stage should be avoided, as it increases the risk of bradyarrythmias. Diuretics must be used with caution, as overdiuresis will lead to intravascular volume depletion and intraoperative hypotension, and may lead to hypokalemia with resultant increased risk for dysrhythmias.
Valvular Disease
Significant aortic stenosis increases perioperative cardiac risk. Patients with known aortic stenosis, or a history and examination consistent with significant aortic stenosis, however, can be operated on safely, provided they have not had congestive heart failure. Patients with severe aortic stenosis (aortic valve area index ≤0.5 cm 2 /m 2 or mean aortic valve gradient ≥50 mm Hg) often develop intraoperative hypotension and require an intraarterial catheter, and possibly pulmonary artery catheterization, for prompt recognition and management.
Patients with known mitral regurgitation or aortic insufficiency, who are asymptomatic with no evidence of decompensation, require no further evaluation. Patients on maintenance diuretics, afterload reduction, and other cardiac medications, should have these medications continued. As with congestive heart failure, patients with evidence of decompensation should be treated aggressively prior to surgery.
Hypertension
Hypertension is a common problem in the elderly. Patients with well-controlled blood pressure have wider fluctuations in both systolic and diastolic pressures intraoperatively, but do not experience more cardiac complications as a result of the hypertension. Antihypertensive therapy should be continued orally or intravenously. Patients whose blood pressure is not well controlled (those with a diastolic blood pressure greater than 110 mm Hg) may be at increased risk for intraoperative and postoperative cardiac complications. Treatment with intravenous antihypertensive medications is warranted and blood pressure should be controlled prior to surgery. Labetalol, atenolol, metoprolol (Lopressor), hydralazine, and enalaprilat are all effective perioperative agents.
Antiplatelet Therapy and Coronary Artery Stents
Patients with coronary artery stents present a challenge to the surgeon. Patients on aspirin and clopidogrel (Plavix) or other antiplatelet therapy, who undergo surgery, have an increased risk of bleeding. Depending on the type of stent, bare metal or drug eluting, and the time since stent placement, the patient will be on at least one antiplatelet medication, and possibly both. Discontinuing antiplatelet therapy and delay of surgery until new platelets are produced is not an option. Discontinuing all antiplatelet therapy is unwise. McFadden and colleagues reported four patients who had their antiplatelet therapy discontinued between 335 and 445 days after stent placement. All four suffered stent thrombosis, one only 4 days after discontinuing both aspirin and clopidogrel. Another patient, on aspirin only, suffered stent thrombosis 5 days after discontinuing the aspirin. In addition to thrombosis, ceasing clopidogrel perioperatively in patients with hip fracture can lead to an increased risk of cardiac events. One recent study revealed that withdrawal of clopidogrel led to an increased incidence of acute coronary syndrome (defined as an increase in plasma troponin >0.04 µg liter−1 ) 4 to 8 days after withdrawal of the medication. Other studies found that when clopidogrel was continued, there was an increase in average blood loss or lower nadir in hemoglobin, but no other adverse effects. In one study, delay in surgery while awaiting the decreased effect of clopidogrel resulted in adverse effects possibly because of the delay. Therefore, all patients on antiplatelet therapy who have stents should continue at least aspirin or clopidogrel during the perioperative period unless absolutely contraindicated.
Pulmonary Assessment
Although cardiac complications are more common than pulmonary complications following a hip fracture, serious pulmonary complications occur at least as often as serious cardiac complications. A systematic review identified the major patient-related risk factors for postoperative pulmonary complications for noncardiac surgery. These included advanced age, American Society of Anesthesiologists class II or higher, functional dependence, chronic obstructive pulmonary disease, and congestive heart failure. Among laboratory predictors, good evidence existed only for serum albumin levels less than 3.0. There was insufficient evidence to support preoperative spirometry as a tool to stratify risk. Obesity has not been found to be a consistent predictor of postoperative pulmonary complications. Delirium, however, is associated with an increased risk for postoperative pulmonary complications.
A recently derived postoperative pneumonia index found that increased risk was associated with weight loss, general anesthesia, impaired sensorium, history of cerebrovascular accident, transfusion of more than four units of blood, emergency surgery, steroid use for chronic conditions, current smoker within 1 year, and alcohol intake of more than two drinks per day for the past 2 weeks.
Most experts suggest aggressive treatment for patients with decompensated obstructive lung disease with β-agonists, ipratropium bromide (Atrovent; an inhaled anticholinergic), and intravenous steroids preoperatively and continued postoperatively. A short course of steroids will not lead to increased postoperative complications. Aggressive measures to prevent atelectasis and postoperative pneumonia, such as early ambulation and the use of incentive spirometry, should be carried out, as the mortality for elderly patients with postoperative pneumonia is significant.
Renal Assessment
Postoperative renal failure has a high mortality, as high as 50%. The serum blood urea nitrogen (BUN) can be misleading, as this test is often affected by the patient’s degree of hydration, gastrointestinal bleeding, and use of medications such as corticosteroids. The best measure of renal function is the creatinine clearance, which gives a rough estimate of the patient’s glomerular filtration rate (GFR). Because the serum creatinine is a function of the muscle mass of the patient, it can often be normal appearing in the face of renal disease in elderly patients with decreased muscle mass. For this reason, we suggest that all patients with a creatinine of 1 mg/dL or higher have their creatinine clearance estimated by either the Cockcroft–Gault equation [Creatinine clearance = (140-age) × weight (kg) / 72 × creatinine (× 0.85 for women)] or the modification of diet in renal disease (MDRD) equation [GFR = 186 × (creatinine) −1.154 × (age) −0.203 × 0.742 if the patient is female or multiplied by 1.212 if the patient is black]. The Cockcroft –Gault equation performs well in patients without known kidney disease, whereas the MDRD is reasonably accurate in those with kidney disease and diabetics. Measurement of GFR by timed urine is no longer recommended.
Because renal function declines with age and fluid shifts may occur perioperatively, a preoperative assessment of renal function is essential. Factors leading to renal function decline include decreased renal blood flow, loss of nephrons, and decreased ability to dilute or concentrate the urine. These changes result in decreased clearance of renally excreted medications; decreased ability to conserve water, leading to hypovolemia; and decreased ability to excrete free water, leading to volume overload.
Several perioperative factors can exacerbate these limitations of apparent normal renal function in the elderly patient. Elderly patients have decreased thirst. This, coupled with the inability to concentrate urine, leads to asymptomatic hypovolemia, which increases the risk for intraoperative hypotension, decreases renal blood flow, and increases the risk for acute renal failure. By inhibiting prostaglandins, nonsteroidal antiinflammatory drugs (NSAIDs), including cycloxygenase-2 (COX-2) inhibitors, must be used cautiously as they decrease renal blood flow and can cause acute renal failure. Patients with a GFR of less than 70 mL/min (correlating to approximately a creatinine of 1 mg/dL in a 70-year-old, 70-kg man) have a further reduction in GFR with NSAID use. Even patients with a GFR greater than 70 mL/min (creatinine approximately 1 mg/dL), but with other risk factors for NSAID-induced renal insufficiency, such as congestive heart failure, cirrhosis, diuretic use, hypovolemia, and sodium-restricted diet, can develop declining renal function with NSAID use. Patients on NSAIDs should have regular BUN and creatinine levels performed. Similar precautions should be adhered to with angiotensin-converting enzyme inhibitors and aminoglycoside therapy, with the addition of monitoring and adjusting serum peak and trough levels for aminoglycosides.
Pain, opiates, and anesthesia all enhance release of antidiuretic hormone. Patients given large volume of fluids may have difficulty excreting free water, leading to volume overload and hyponatremia. In the first 1 to 2 postoperative days, intravenous diuretics may be needed to assist in the elimination of perioperatively administered fluid as it mobilizes from the extravascular to intravascular space. Symptoms and signs of early intravascular volume overload include increased weight, dyspnea, jugular venous distention, pulmonary crackles, and dependent edema. Patients with congestive heart failure may require up to 5 days to completely eliminate excess fluids.
Hepatic Disease
The anesthesiologist must closely evaluate patients with decreased hepatic function. The selection of the anesthetic agent is important because these agents, both general and regional, reduce hepatic blood flow, may increase liver damage, and may be metabolized and excreted by the liver. Patients with hepatic failure must be monitored specifically for disorders of coagulation, namely with the prothrombin time, gastrointestinal hemorrhage by testing stools for occult blood and serial complete blood counts, and portosystemic encephalopathy by testing for orientation, asterixis, and serum ammonia levels.
Patients with jaundice are at increased risk for postoperative renal failure, with an incidence of 8.4% and a mortality rate in those cases of 64.1%. Risk is proportionate to the serum bilirubin level. Jaundiced patients are more likely to become hypotensive perioperatively because of an increased sensitivity to hypovolemia from decreased peripheral vascular resistance. In addition, bilirubin, when combined with perioperative hypotension, may potentiate renal ischemia. Finally, these patients have fewer bile salts in the intestinal lumen, resulting in enhanced absorption of endotoxin, and have decreased degradation of endotoxin caused by depression of the reticuloendothelial system. Elevated endotoxin levels can decrease renal perfusion, cause disseminated intravascular coagulation, acute tubular necrosis (ATN), and thrombotic glomerulopathy.
Laboratory Assessment
Preoperative laboratory assessment aids the evaluation. Some controversy exists over the extent of “routine” testing. Because of the increased incidence of comorbid conditions in the elderly, and the inability to obtain a history in some patients, a complete blood count, platelet count, serum electrolytes, BUN, glucose, chest radiograph, and electrocardiogram should be obtained. Prothrombin time (PT) and partial thromboplastin time (PTT) should be reserved for those patients unable to give a history, or, who on history, either personal or family, or examination, have a suggestion of a bleeding diathesis. Routine ordering of PT and PTT has not been shown to be of benefit in low-risk patients. Further testing can be obtained based on the history and physical.
An evaluation of nutritional status should be done and a serum albumin level obtained in all patients. Malnutrition is common in hospitalized patients and is often unrecognized by physicians, may be found in up to 20% of hip fracture patients, and is associated with increased morbidity and mortality. Albumin levels below 3.0 g/dL predict increased mortality at 1 year. Several studies have demonstrated the benefit of oral protein supplementation postoperatively. Patients who received supplementation had better 6-month outcomes, improved albumin, and shorter length of stays. Evidence suggests that patients with evidence of malnutrition should receive postoperative oral protein supplements.
Related posts:
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
