Mrs. F, your 91-year-old patient, comes to the office because she has noted small amounts of blood on the toilet tissue when she moves her bowels. She is healthy, cognitively intact, and lives independently. She walks about 2 miles per day when she does her errands, does not use a cane, and has not fallen. She is socially active and is in touch with family and friends who live nearby. Approximately 9 years ago, the patient underwent abdominal hysterectomy for nonmalignant vaginal bleeding, and tolerated the procedure well. She has no history of cardiovascular disease.
On physical examination, Mrs. F looks well and is not pale. She is alert and interactive, with obvious normal mental status. Blood pressure is 150/80, pulse is 72 and regular. Lungs are clear. She has a grade II/VI systolic ejection murmur in the aortic area. She has no peripheral edema. Rectal examination reveals guaiac positive stool; no masses are palpable.
Colonoscopy is performed and reveals a large mass in the proximal sigmoid colon, which cannot be removed colonoscopically. Abdominal computed tomography (CT) scan demonstrates no metastatic disease.
Surgery is recommended but the patient demurs, saying she is afraid to have such a major procedure at her age.
Questions
1. How should Mrs. F’s concerns be addressed?
2. What preoperative considerations should determine her surgical risk? 3. What kind of preoperative evaluation should she undergo and why? 4. What kind of postoperative issues will be important?
Case Studies in Geriatric Medicine, Judith C. Ahronheim et al. Published by Cambridge University Press. C
Answers
1. The benefits and potential risks of this surgery should be explained to Mrs. F. In particular, she should be made aware that age alone does not determine whether surgery can be performed safely. Surgical risk depends more on the seriousness of the surgery and on the existence of underlying disease.
Elderly patients who are otherwise well and have a high degree of function have an operative risk that is nearly as low as younger age groups when surgery is nonemer- gent. Reported series of very old adults undergoing various types of nonemergency surgery suggests that they tolerate the surgery or anesthesia well (see Hosking et al., 1989; Warner et al., 1998). Published series suggesting good outcomes in the oldest age groups, however, may reflect very careful selection of patients, or less invasive surgical procedures. Thus, the patient should be made aware that her overall health and function are high and that a careful risk assessment will precede any proposed surgery.
It is important to emphasize to the patient that she has a potentially curable lesion. Limited study reveals that older patients undergoing resection of carcinoma of the colon do not have significantly higher postoperative mortality than younger adults (Irvin, 1988). As with other types of surgery, baseline physical and neurologic function, as well as underlying medical problems, seem more important predictors of survival and complication rate. Patients with advanced stage of disease have shorter survival postoperatively, as would be expected, but even if Mrs. F’s cancer proved to be locally invasive, it would be entirely possible, given her advanced age, that she might still die of an unrelated cause before the cancer had a chance to metastasize and impair her quality of life.
2. Numerous risk assessment indices have been developed to predict patient outcomes following surgery, and widely used indices focus on cardiovascular or general mor- bidity and mortality. Degree of risk is determined by patient factors and whether the type of surgery is inherently low, intermediate, or high risk. Although advanced age is generally considered an independent risk factor, the weight given to age in these indices does not alone confer increased surgical risk; patients as old as Mrs. F, and even centenarians, may do well if carefully selected. However, older patients do tend to have a higher complication rate than expected, even if they are preopera- tively determined to be at “low” risk. This may reflect a high rate of silent disease, especially cardiac disease, in the older age group.
Morbidity and mortality are also related to the type of surgery. High or inter- mediate risk procedures, such as vascular, thoracic, or abdominal surgery, or hip arthroplasty, might pose a greater risk than a “low risk” (superficial) procedure such as cataract extraction or mastectomy. The apparent innate risk of specific
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procedures may be further enhanced by the common comorbidities that exist in patients who require them – for example, patients undergoing vascular procedures would be expected to have a higher burden of atherosclerotic risk factors, and abdominal surgery for potentially invasive colon carcinoma would be associated with a higher inherent risk of infection.
Another determinant of risk is whether the surgery is emergent or elective. In elective surgery, patients can be carefully selected and prepared. The inherent risks of emergency surgery are enhanced in the elderly, often because atypical presentations lead to delayed diagnosis (see Case 31) or because concerns over outcome lead to indecision and temporizing until the patient has clinically deteriorated. Thus, although this patient’s surgery is not yet an emergency, it would be important to avoid unnecessary delay.
Although risk indices address the most common forms of perioperative mor- bidity, they do not address the risk of postoperative cognitive decline, which is a concern of many patients and their families. It is difficult to identify the risk factors for poor cognitive outcome following surgery because those with baseline cognitive impairment are more likely to deteriorate in the long term even if they have not undergone surgery.
3. In assessing the elderly for surgery, overall function and general health are very important, but cardiovascular, renal, and brain function deserve special attention. Mrs. F’s systolic blood pressure is mildly elevated and, because she has no known history of hypertension, it is possible that her systolic blood pressure is labile and not sustained (see Case 14). Whereas careful preoperative evaluation and treatment are generally recommended if blood pressure exceeds 180/110, treatment of mild, labile systolic hypertension could theoretically worsen outcome by increasing the risk of intraoperative hypotension.
Of greater concern is the increased prevalence of silent cardiac disease in late life. Although asymptomatic at this time, Mrs. F has a cardiac systolic murmur. A systolic murmur in the elderly could indicate aortic stenosis, which increases in incidence with age. Severe aortic stenosis (valve area less than approximately 0.8 mm2) is the main type of valvular heart disease associated with perioperative
cardiac complications, including heart failure, myocardial infarction, and death. Although aortic stenosis (AS) may be asymptomatic until very late and significant AS can be missed, significant AS is very unlikely in this physically active patient.
As discussed in Case 2, murmurs of aortic origin in asymptomatic patients can be due to aortic sclerosis or mild stenosis, which should not themselves affect surgical outcome, although they are markers of silent coronary artery disease. According to existing guidelines, Mrs. F, who does not have symptoms of severe valvular heart disease, and who would be undergoing an intermediate risk procedure (intraperi- toneal surgery), does not technically require preoperative cardiac evaluation, since
intervention would only be justified if it were indicated regardless of whether she were having surgery (see Eagle et al., 2002). One could, however, justify an evaluation to identify specific problems that would lead to recommendations for periopera- tive care. For example, diagnosis of aortic stenosis would lead to the avoidance of spinal anesthesia in certain surgeries, or, since auscultation may be misleading in the elderly due to thoracic and other anatomic changes, delineation of a “moderate risk” valve abnormality might prompt endocarditis prophylaxis a few hours before surgery.
Certain general caveats bear mentioning in the elderly, and would be pertinent to this patient. Although evidence does not support that “routine” preoperative testing adds to information recently gleaned, certain baseline information is helpful in perioperative management because of the high rate of overt and silent comorbidity. For example, a preoperative electrocardiogram (EKG) may be important because previously asymptomatic elderly may develop new EKG changes postoperatively. Laboratory evaluation helps to identify diseases such as diabetes and anemia, which are manageable, and liver disease, which require specific perioperative precautions. Baseline hemoglobin determination is important since drops in blood count can lead to ischemic events, and this requires extra attention in elderly patients for whom any “standard” threshold for transfusion might not apply. Although the presence of renal disease is predictive of postoperative renal failure, a normal baseline serum creatinine determination often masks renal insufficiency in the elderly. It is not necessary for the patient to undergo a 24-hour urine collection because this is cumbersome and would not change the need for vigilance. Rather, it is import- ant to assume, based on the patient’s age, that renal function may be lower than expected, and doses of renally eliminated medications (or hepatically metabolized medications with active metabolites) would need to be determined judiciously (see Case 20). Several important perioperative medications for which geriatric dosing precautions are often not considered include opioid analgesics, aminoglycoside antibiotics, and enoxaparin. Meperidine (Demerol; pethidine) is an opioid that should be avoided in the elderly because one renally eliminated metabolite can produce seizures.
Preoperative urinalysis may be useful if bladder catheterization is intended, to establish a baseline, because of the high prevalence of asymptomatic urinary tract infections in the elderly and because of the high risk of catheter-associated urinary tract infection.
4. Barring any unpredictable event, Mrs. F’s high physical and cognitive function make her – on the surface – an excellent surgical candidate for her age. Postoperatively, it would be very important to monitor her for problems that cannot be predicted by her preoperative evaluation. These would include drug toxicity (owing to occult renal dysfunction or altered sensitivity), delirium (due to preclinical brain disease
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and brought on by drug toxicity, infection, or other medical insults), and cardio- vascular events (owing to silent coronary artery disease, especially in the event of blood loss).
Thoracic and upper abdominal surgery and prolonged anesthesia are associated with a risk of pneumonia, and this risk is greater in older adults. This patient would otherwise be at lower risk because she is a nonsmoker and does not have a history of pulmonary disease. Nonetheless, it would be prudent to encourage her to perform incentive spirometry, and to be out of bed to chair, and to ambulate, as soon as possible. The physician should prescribe adequate analgesia to encourage cough, while being mindful of the increased risk in older adults of fecal impaction, confusion, and falling. If opioids are given around the clock, the patient must be re-evaluated frequently because active drug metabolites will accumulate and oversedation may occur in a delayed fashion. Despite her baseline ambulatory capability, opioid analgesics and delayed effects of anesthesia might increase her risk of falling and appropriate precautions should be instituted.
Prophylaxis for deep vein thrombosis should be given as in any postoperative patient, with careful attention to dosing (see Case 26).
Delirium is a common postoperative problem in the elderly. Controversy exists as to whether this is more likely in those with impaired cognitive function. Peri- and postoperative delirium are very common, and permanent postoperative decline in cognitive function sometimes occurs, although the risk of this is uncertain. Delirium (as well as persistent cognitive impairment) may occur in elderly patients with no documented history of dementia, possibly because they have preclinical dementia, or because of age-related factors affecting drug disposition. Infection, which is common following abdominal surgery, is a common cause of delirium in frail elderly. Perioperative delirium can be minimized with careful attention to medication regimens, avoidance of restraints, optimization of sensory stimuli, early recognition of delirium, and prompt treatment of medical comorbidities. Delirium is discussed further in Case 20.
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