After evaluating this article, participants will be able to:
1. Better recognize the effects of aging on the presentation of abdominal pain in the elderly
2. Incorporate strategies into practice to avoid common pitfalls in treating elderly patients with abdominal pain
3. Develop mechanisms for the appropriate evaluation of elderly patients presenting with abdominal pain
How to navigate this growing minefield within the emergency medicine patient population
Don’t look now, but that gentle lapping at your toes is the first hint of the “silver tsunami” coming soon to an emergency department near you. Of the 313 million people currently living in the United States, 12% are over the age of 65 years, and one million are over 100 years old. More sobering, as of January 1, 2011, the first baby boomers started to qualify for Medicare. With a paucity of primary care physicians, many of these older patients are coming to the emergency department for their medical care, and this trend is likely to continue. Currently, patients over age 65 account for 12-24% of all ED visits, and when they arrive (by ambulance around a third of the time), they are sicker and are more likely to be admitted, often to the ICU. In fact, when compared to younger patients, older patients are two to four times as likely to be admitted, and have a five-fold higher rate of ICU admission. Clearly, as this wave of older patients starts crashing over our emergency department doorsteps, emergency physicians need to be prepared to care for this burgeoning portion of the emergency patient population.
Abdominal pain is the chief complaint in 3% to 13% of older patients coming to the emergency department. These patients are six to eight times more likely to die and twice as likely to need surgery as their younger counterparts. Misdiagnosis is common, ranging from 18% to 60%. Given these statistics, it is not surprising that emergency physicians report having difficulty with elderly patients with abdominal pain.
The Effects of Aging
Anyone who works in an emergency department knows that caring for the older patient can pose a challenge. Getting a clear medical history from a patient with dementia is virtually impossible and often requires some detective work, such as gathering information from family, past medical records and other physicians to get a clear picture of what might be wrong with the patient. Even the most mentally sharp older patient often has physiologic changes occurring with aging that confound their emergency evaluation. A patient’s ability to localize symptoms is dulled with aging, and elder patients may present with only fatigue or generalized weakness, even in light of a potentially life-threatening illness or infection. With age, patients have a delay in developing a fever and may have less of a temperature elevation when compared to younger patients. Preexisting medical conditions or prior surgical procedures can be a hindrance or a help, and emergency providers need to take particular care not to come to “premature closure” when considering possible diagnoses, and keep an open mind as they evaluate these patients.
While judicious use of medications can be vital to maintaining the health of an older patient in the outpatient setting, these same medications can complicate their evaluation in the emergency department. Statistically, the elderly consume over 30% of the prescription medications used in the United States, and this percentage is expected to increase to 50% by 2020. Ten percent of elders take 4 or more drugs a day and ten percent take 10 or more daily. These statistics support the data that shows 10-30% of admitted elders have drug interactions or reactions that contribute to their admission. For emergency providers, these medications may affect vital signs (e.g. beta-blockers can dampen the tachycardia expected to be associated with bleeding), can exacerbate an emergent condition (e.g. warfarin increasing bleeding), or may even be the cause of the patient’s abdominal pain (e.g. ulcer disease from the use of nonsteroidal anti-inflammatory agents).
Aging also has direct effects on the abdomen of an elder patient. Thinning of the gastric mucosa, decreased mucous production and a decrease in bicarbonate secretion increase the risk of gastrointestinal bleeding. Thinner abdominal musculature decreases the patient’s ability to guard or rebound, so patients with intra-abdominal catastrophes such as a perforated viscus may appear deceivingly benign. A more tenuous circulation increases the risk of not only vascular emergencies such as abdominal aortic aneurysm rupture and mesenteric ischemia, but also increases the risk of perforation in patients with appendicitis and cholecystitis.
Interestingly, most laboratory test results are not altered significantly by aging. Anemia is not associated with aging, and a low hematocrit signifies true finding. However, for any given infectious process, older patients have a delay in developing an elevated white count when compared to their younger counterparts, so a lack of an elevated white blood cell count should not be reassuring when considering an infectious cause of the patient’s abdominal pain.
The changes associated with aging require the emergency care provider to understand that while it remains important to obtain the elements of the history of present illness, most elderly patients don’t “read the textbooks” and may not present “classically”. One historical element that is particularly useful, however, is pain that is abrupt and severe at onset. This complaint often signifies an intra-abdominal catastrophe (ruptured abdominal aortic aneurysm, perforated viscus, mesenteric ischemia) and should alert the emergency physician. Past medical and surgical history and a complete medication list, if available, are helpful.
Physical exam findings are highly variable in these patients. Vital signs may be normal even with serious illness, sometimes due to the changes from aging (such as seen with a lack of a febrile response) or due to medications. While an abnormal physical exam is helpful, patients may have life-threatening illnesses despite a benign physical exam.
Knowing that elder patients with abdominal pain may have a serious cause with a paucity of findings, laboratory testing and imaging are often the mainstay of evaluating these patients. In addition to the usual laboratory studies (complete blood count, electrolytes, a liver panel, lipase level and a urinalysis), it is prudent to consider ordering a lactate level (in cases of suspected mesenteric ischemia) and coagulation studies. Plain films are used primarily to look for free air in cases of suspected viscus perforation or for bowel obstruction. Ultrasound evaluates the gall bladder and pelvic organs, and bedside ultrasound is highly useful in the patient with abdominal pain and hypotension to evaluate for abdominal aortic aneurysm. CT scanning is highly useful and can identify many of the causes of abdominal pain in these patients.
The differential diagnosis of abdominal pain in the elder patient is extensive, and data from emergency departments and hospitals reveal a sobering statistic: Over 60% of these patients have a surgical disease, and 30% need an operation for their complaint. While the list of possible diagnoses is extensive, understanding the odds of any particular diagnosis will help focus the evaluation of these patients. Table 1 (above) shows the causes and percentages of these diagnoses.
If you’re putting money down, place your bet on the biliary tree, which accounts for nearly one in five cases of abdominal pain in this population. Obstruction, perforated viscus, diverticular disease and appendicitis each account for 5-10%. Hidden in the “miscellaneous” category are some killers, such as ruptured abdominal aortic aneurysm and mesenteric ischemia. All told, the majority of cases are due to surgical disease, and some of those are potentially deadly.
Considering the array of pitfalls in evaluating these patients, emergency physicians should be very cautious when considering discharging an elderly patient with abdominal pain. If your pen on the paper or your fingers on the keyboard start writing “discharge”, take a step back and think again. If you’re still convinced it is safe to discharge the patient, assuring follow up within 1-2 days and reinforcing that the patients can return to the emergency department at any time is prudent.
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