Chapter 32 Elderly Patients
Why geriatric anesthesiology is important
Age-Related Physiologic Changes
6. How is organ function affected by aging? How might this affect the elderly patient in the perioperative period?
7. What age-related changes in systolic blood pressure, heart rate, cardiac output, stroke volume, and cardiac conduction occur in the elderly?
8. Why are elderly patients more susceptible to congestive heart failure when subjected to fluid overload than younger counterparts?
9. How do drug-induced heart rate changes in the elderly compare with the heart rate response seen in younger patients administered the same drugs?
10. How do reflex-mediated heart rate increases in response to hypotension differ between elderly and younger patients?
11. What age-related changes in gas exchange, the alveolar-to-arterial oxygen gradient, and the ventilation-to-perfusion ratio occur in the elderly?
12. What age-related changes in vital capacity, forced exhaled volume in 1 second, residual volume, and functional residual capacity occur in the elderly?
13. How do ventilatory responses to hypoxia and hypercapnia change with age? Why is this particularly important to the anesthesiologist?
14. Why does pneumonia occur at an increased frequency in elderly patients?
15. What age-related changes in renal blood flow, glomerular filtration rate, and urine-concentrating ability occur in the elderly? What clinical implications do these have?
16. How do plasma concentrations of creatinine change with age?
17. What age-related change in hepatic blood flow occurs in the elderly? What clinical implication does this have?
18. How does the production of albumin change with age? What clinical implication does this have?
19. What age-related changes in esophageal and intestinal motility and gastroesophageal sphincter tone occur in the elderly? What clinical implications do these have?
20. What clinical relevance do the age-related loss of collagen and decreases in skin elasticity have for the anesthesiologist caring for the elderly patient?
21. What clinical relevance do osteoporosis, osteoarthritis, and rheumatoid arthritis have for the anesthesiologist caring for the elderly patient?
22. What age-related changes in the central and peripheral nervous systems occur in the elderly? How does this affect the minimum alveolar concentration (MAC) of anesthesia in the elderly patient?
23. What physiologic changes occur with aging that predispose the elderly patient to hypothermia?
Perioperative care in the elderly
24. Why is it important to inquire about functional status in the elderly patient?
25. What are some elements of the preoperative evaluation that are of particular relevance to elderly patients?
26. What are some examples of activities of daily living (ADL) and instrumental ADLs (IADL)?
27. Should preoperative testing include a routine electrocardiogram (ECG) based on an age cutoff in elderly patients?
28. What are some of the challenges when obtaining a preoperative assessment in an institutionalized patient?
29. Why should certain antihypertensive medications be held on the morning of surgery?
30. What are some of the physiologic consequences that might be observed in elderly patients taking diuretic medications?
31. How are pharmacodynamic changes in the elderly reflected with regard to inhaled anesthetics and opioids?
32. How are pharmacodynamic changes in the elderly reflected with regard to nondepolarizing neuromuscular blocking drugs?
33. What pharmacokinetic changes in the elderly make them susceptible to cumulative drug effects and adverse drug reactions?
34. What age-related changes in the elderly result in a decreased clearance of drugs? Give some examples of drugs whose elimination times may be affected.
35. What age-related changes in the elderly result in changes in the volume of distribution? Give some examples of drugs whose pharmacokinetic properties may be altered.
Choice of anesthesia
36. What is an advantage that regional anesthesia may have over general anesthesia for hip surgery in elderly patients?
37. In an awake, elderly patient, what is the significance of orthostatic hypotension without an associated increase in heart rate?
38. What is the potential significance of mental status changes that occur with extension and rotation of the head?
39. Why should preoperative anxiolytics be used sparingly in the elderly population? What can be used as a substitute?
40. Why might hand ventilation by bag and mask be difficult in the edentulous patient?
41. Why might endotracheal intubation be difficult in a patient with poor dentition or cervical arthritis?
42. How should the induction dose of anesthetic be altered in the elderly patient?
43. Are there any unique risks to the elderly with the reversal of nondepolarizing neuromuscular blocking drugs with anticholinesterase drugs?
44. What are some postoperative risks that elderly patients are more prone to than younger patients?
45. What types of procedures that elderly patients are likely to undergo might warrant regional anesthesia as an alternative to general anesthesia?
46. What is the advantage to maintaining consciousness in the elderly patient during a regional anesthetic for a surgical procedure?
47. What are some reasons why elderly patients may be more sensitive to regional anesthesia than younger patients?
48. How might the hypotensive effects of a sympathectomy resulting from regional anesthesia be attenuated?
49. What advantage does epidural anesthesia have over spinal anesthesia that can be of particular benefit in the elderly population?
Postoperative care
50. What are some of the consequences of untreated postoperative pain in the elderly patient?
51. What are some examples of adjuvant nonopioid medication that can be used to treat pain in the elderly patient?
52. What are some of the advantages of postoperative epidural analgesia in elderly patients?
53. How should a regional technique be altered in an elderly patient?
54. What are the most common postoperative neurologic events in elderly patients?
55. When is postoperative delirium in the elderly patient most likely to present?
56. What are some possible clinical manifestations of postoperative delirium in the elderly patient?
57. What are some causes of postoperative delirium in elderly patients?
58. What are some of the consequences of delirium in elderly patients?
59. How is postoperative cognitive dysfunction different from delirium?
Answers*
Why geriatric anesthesiology is important
1. The elderly population represents a heterogeneous group of individuals with widely varying functional and reserve capacity. In some patients there may be a wide disparity between the chronologic and physiologic age. In all individuals, aging is associated with a gradual deterioration of organ function. Even though the rate may vary between individuals, some age-related changes are inevitable. Elderly patients may also exhibit atypical symptoms leading to delays in diagnosis and more advanced disease at presentation. Other challenges include polypharmacy, the high prevalence of dementia and cognitive dysfunction in the very elderly, and the difficulty in estimating functional reserve in patients with limited mobility and multiple comorbid conditions. (568, Table 35-1)
2. Advanced age is a risk factor for surgical morbidity and mortality. Elderly patients who require surgery are also at a greater risk of perioperative complications than their younger counterparts. This is due to a combination of the effects of chronic disease and generalized age-related decreases in organ function. Some examples of common age-related changes include a generalized decrease in maximal breathing capacity, vital capacity, glomerular filtration rate, and basal metabolic rate. In addition, decreases in the elderly patient’s level of activity may lead to deconditioning and a subsequent inability of the cardiovascular system to respond to perioperative stressors. Overall the comorbid conditions found in elderly patients are the most significant contributors to the development of perioperative complications or perioperative death, rather than the age of the patient itself. (568, Figure 35-1)
Morbidity and Mortality Rates
3. The need for emergency surgery is one of the most important predictors for mortality following surgery in older patients. The circumstances of the emergency itself may be compromising the patient’s physiologic status, such as with hemorrhage or dehydration. In these circumstances the older patient with poor baseline function and organ reserve may not be able to respond rapidly to this acute alteration in physiologic state. In addition, emergency cases preclude the preoperative time necessary to control coexisting diseases and maximize organ function. The lack of optimization impacts the ability to withstand the stress imposed by surgery. Other important factors influencing the outcomes in elderly patients include delayed presentation of a condition, high ASA physical status, partial or complete immobility, intracavitary surgery, and congestive heart failure. Older patients tend to present later with more advanced disease and thus be more compromised physiologically at presentation. (569)
4. Complications may be poorly tolerated in very old patients. Patients over 80 years old who developed a postsurgical complication had a fourfold increase in mortality. Complications are also associated with an increase in length of hospital stay and morbidity. The most significant complications include cardiac arrest, renal failure, and myocardial infarction. Avoiding even minor complications is one of the cornerstones of management of geriatric patients undergoing anesthesia and surgery. (569)
Medications to Avoid in the Geriatric Population
5. Aging is associated with decreased central cholinergic reserve, and in elderly patients with dementia this may be significant. Scopolamine is a tertiary quaternary amine and as such crosses the blood-brain barrier. The central anticholinergic effects of scopolamine may lead to significant delirium in elderly patients. Other medications that can similarly cause delirium through central anticholinergic effects include atropine, chlorpheniramine, diphenhydramine, and promethazine. (570)
