H. Russell Harvey, M.D.
Consultant Anesthesiologist and Intensivist
2702 Vigilante Trail
Billings, MT 59102
tamazyn@yahoo.com

Douglas B. Coursin, M.D. (corresponding author)
Professor of Anesthesiology and Internal Medicine
Associate Director of the Trauma and Life Support Center
B6/319 UW CSC
Madison, WI 53792-3272
dcoursin@facstaff.wisc.edu

Case: A pale, frail, but intellectually active 71 y/o female presents with hematemesis and tarry stools over the past 24 h. Her BP is 110/60 with a 30 ö 40 mm drop when she sits up, pulse 110, RR - 20. She has long-standing rheumatoid arthritis and is treated with daily hydroxychloroquine, ranitidine and aspirin 650 mg q 4 ö 6 h (it was more efficacious than her NSAI or COX-2 inhibitor). She was slowly tapered off steroids 4 months prior to admission. Her baseline creatinine is 1.4 mg/dL and hematocrit (Hct) 30. Her Hct today is 22.

Discussion

The importance of age to our critically ill patients is clear: advanced age (> 65) has been shown in multiple studies to be an independent risk factor associated with increased morbidity and mortality.¹ However, in the trauma and burn populations, age > 50 may also impact on outcome when compared to younger patients.² The presence of co-morbid diseases such as chronic obstructive pulmonary disease (COPD), atherosclerotic heart disease (ASHD), diabetes, renal or hepatic insufficiency and immune suppression further compound the effect of age on survival. Although questioned in the past, there is good data in the United States that critical care improves outcome in the elderly and that age should not be arbitrarily used to withhold admission. There is also increasing data that early, direct ICU admission for some elderly critically ill patients not only prevents a later transfer from the general ward, but favorably impacts survival as well. It is necessary to recall the normal decline in end-organ function that occurs in the elderly and remember that even modest appearing insults can precipitate significant sequelae. For example, our frail elderly female develops orthostasis from an aspirin-induced gastritis or ulcer with hemorrhage and significant hypovolemia. Although her baseline creatinine of 1.4 is only moderately elevated (normal is <1.0), with her low muscle mass and modest nitrogen intake, this may reflect significant renal compromise (intrinsic disease related to nephrosclerosis, rheumatic disease, drug toxicity, etc.) that can be further exacerbated by under-resuscitation.

Decline in Organ Function

All of us suffer a decline in basic organ function as we age, independent of disease processes. This is true across the board, affecting basic receptor function and intracellular second messenger systems, as well as all major organ systems (see Table #1). The common thread running through the organ changes is the decreased ability to adapt to a challenge to homeostasis.³Our frail GI bleeder has systemic disease that further compromises her reserve. She appears to have anemia of chronic disease, decreased renal function, may be unable to mount a normal stress response secondary to adrenal suppression and may have other end-organ problems such as restrictive pulmonary disease, cardiomyopathy, and/or diastolic dysfunction.

Decreased Physiologic Reserve

Changes in the heart, vasculature, lungs, kidneys and liver bring about a decreased physiologic reserve. The obligatory decrease in function (e.g., the increased[ A-a O_2] gradient secondary to the decreased ratio of FRC to closing capacity) means less "headroom" above baseline for our elderly critically ill patients.

Increased Prevalence of Chronic Disease

The elderly suffer an increased prevalence of chronic disease. Across a greater span of years, the cumulative effects of inactivity and poor choice of habits increase. Add to this the increase in exposure to both the environment and genetic pedigree. Unless we are both good (exercise, eat an optimal diet, never smoke, use alcohol in moderation and avoid trauma) and lucky (good genes, low cholesterol, avid immune responder), few of us will reach latter years free of chronic and potentially debilitating disease. It is clear that much of the increase in morbidity and mortality in the elderly is related to concomitant disease, and not to age alone. Both in critically ill elderly patients and in elderly patients having major surgery, the increase in risk is secondary to the presence and number of disease states.^3-7What do these principles imply? Older patients have more physiologic variability than younger patients. They are more dissimilar. The mandated changes in basic function and physiology notwithstanding, an active, healthy 80-year-old may be very different from an inactive, chronically ill 70-year-old. The presence of chronic diseases and their number make for very different risk profiles. All elderly patients have decreases in cellular and organ function. All walk much closer to the limits of their ability to compensate for a perturbation in homeostasis. The variability between patients requires an individualized plan, with the risks determined in light of the patientās history, the limits on reserve dictated by age and by the current disease process. In the elderly, the difference between "poor" health and "good" health is very important.

Summary

This elderly patient has chronic compromise secondary to the systemic effects of rheumatoid arthritis and its therapy. She is at risk for adrenal (iatrogenic steroid deficiency) and immune suppression (secondary to RA and its therapy) and progression of her renal insufficiency. In addition, she has decreased physiologic reserve related to the aging process; this may be unmasked if therapy is delayed or overly aggressive therapy is undertaken. Therefore early ICU admission, consultation with gastroenterology and general surgery, and definitive therapy with blood, fluids and steroids are required. She should have an arterial and central venous catheter placed. This will facilitate monitoring of volume status, adequacy of her fluid replacement and pre-emptive care if she requires additional endoscopic, radiographic or surgical care. It would be reasonable to obtain a co-syntropin stimulation to evaluate her hypophyseal-adrenal axis. In contradistinction to hydrocortisone or methylprednisolone, dexamethasone will provide stress hormone coverage without interfering with this test. Further steroid dosing will depend on test results. The optimal hematocrit for the critically ill continues to be open to discussion, but it is crucial to provide adequate intravascular volume.⁸ Finally, additional monitoring (gastric mucosal pH_i, mixed venous oxygen saturation, or the like) may be used on a patient-to-patient basis to identify adequate tissue oxygenation.⁹

Table: Organ System Changes with Age

Circulatory vascular compliance, - resistance Subsequent - systolic BP, ø effective circulating volume Cardiac - afterload leads to - LV wall stress and leads to LVH and ø LV compliance Cardiac output - with an - in LVEDV, not with an - in inotropy Pulmonary ø chest wall compliance: ø TLC, VC, - FRC, ø lung elastic recoil, - lung compliance, - closing capacity Renal Fewer cortical nephrons, ø GFR Nervous ø responsiveness to autonomic nervous system, ø decreased response to exogenous a and ß agonists (mix of receptor and second messenger defects) ø response to stress

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