Atypical Presentations of Critical Illness in Older Adults

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Authors: Kimberly Bambach, MD, Katherine Buck, MD

Edited By: Angel Li, MD, Shan W. Liu MD, SD

Updated: August 16, 2021

Case Study

An 88 year old female with a history of hypertension, GERD, and gastritis presents with abdominal pain and fatigue for the past three days. Her abdominal pain is “everywhere” and does not feel more prominent in a specific region. She denies fever, but endorses chills and generalized weakness. She reports poor appetite over the past three days with persistent nausea but no vomiting or diarrhea. She has never had similar symptoms before and has no history of prior abdominal surgeries. Vital signs are as follows: HR 90, BP 98/53, T 97.5° F, RR 18, SpO2 99% on room air. On examination, she appears uncomfortable. Her abdomen is soft with diffuse mild abdominal tenderness to palpation but no rebound tenderness or guarding. The remainder of her examination is normal.

30 minutes after you have evaluated the patient, the nurse calls you to inform you that her blood pressure is now 80/49.


By the end of this module, the student will be able to: 

  1. Appreciate that critical diagnoses often present atypically in older adults
  2. Describe factors affecting emergency care of older adults including physiologic changes of aging, medication effects, intrinsic factors, and social factors
  3. Discuss the hallmarks and limitations of history and physical exam in the evaluation of older adults with critical illness
  4. Recognize signs and symptoms of sepsis in older adults
  5. Create a broad differential for older adults presenting to the Emergency Department with atypical chest pain and abdominal pain
  6. Provide a rationale for labs and imaging choices in older adults with vague symptoms


Older adults, defined as age 65 and older, often present to the Emergency Department (ED) with disease processes that confer high morbidity and mortality. However, identifying critical pathology is challenging and requires a high index of suspicion. Signs of critical illness in older adults may be subtle or atypical, meaning that their presentation often deviates from typical “illness scripts”, which represent the patterns in history or physical exam associated with a specific disease process.  Atypical presentations occur for many reasons, including the physiological changes of aging, medication effects, and factors that limit history or physical exam (Table 1). 

Typical findings in geriatric patients, such as fever or leukocytosis, may be absent due to immunosenescence, an age-related decline in immunity. Pain perception may be altered due to age related changes in the nervous system. For this reason, peritoneal signs in the acute abdomen may be absent. Polypharmacy or medication effects can also blunt or mask physiologic responses to illness or place patients at risk for adverse effects. It is also important to consider how multiple comorbidities and lack of physiologic reserve increase diagnostic complexity. Older adults may also have cognitive decline or limited social support that limit the history of the present illness or exacerbate the underlying illness.

Table 1: Factors contributing to atypical presentations in older adults
Physiologic changes of agingMedication effectsOther factors
Decreased pain and temperature perceptionBeta blockers or calcium channel blockers mask tachycardiaMultiple comorbidities
Decreased humoral and cell mediated immunityChronic steroid use blunts immune responseDementia, delirium, or cognitive decline limits history
Decreased response to pyrogensChronic analgesics blunt pain perception
Functional dependence or living in a care facility
Decreased renal functionAdverse effects of medicationsLimited social support

Initial Actions and Primary Survey

Evaluation of older adults in the ED begins with evaluation of the ABCs. Evaluate the patient for signs of aspiration or airway obstruction, inadequate respirations, and poor perfusion which indicate critical illness. This helps to establish if the patient is “sick” or “not sick”. 

Critically ill patients require rapid intervention before proceeding with the history. Initial actions include establishing IV access (two large bore IVs if hemodynamically unstable), administering supplemental O2 if hypoxic, and placing the patient on the monitor. Obtain a STAT point of care glucose in any patient with altered mental status, as hypoglycemia is a common cause of encephalopathy. A STAT ECG in a patient with vague symptoms or a patient who is ill appearing can indicate myocardial ischemia or arrhythmia.

Atypical Presentations

Older adults with high-risk pathology may have chief complaints that are vague and they may under report symptoms. Patients often describe malaise- they just “don’t feel right”. Sepsis, for example, may present with a chief complaint of fatigue, anorexia, weakness, or confusion rather than fever or a localizing symptom. For example, sepsis due to a urinary tract infection often presents as altered mental status in older adults. In a patient with an acute surgical abdomen due to appendicitis, abdominal pain may be diffuse rather than localized to the right lower quadrant or periumbilical regions. A patient with a STEMI may not have chest pain at all and may simply feel tired, nauseated, or have isolated jaw, arm, shoulder, or abdominal pain. For this reason, it is important to maintain a high index of suspicion for critical illness. 

Falls are also a common presentation for ill geriatric patients and the patient may require a trauma assessment. However, it is important to consider medical illness as well and explore why the patient may have fallen. How was the patient feeling prior to the fall? Was the fall mechanical or due to another process such as syncope? 

It is important to elucidate the patient’s baseline functioning when obtaining a history. Understanding the patient’s ability to perform the activities of daily living (ADLs) can aid with diagnosis and management and give context to their ED presentation. One tool that can aid in elucidating important components of the patient’s history is the 4Ms Framework of an Age Friendly Health System: Mobility, Medications, Mentation, and what Matters. Has there been a decline in mobility? Was a new medication started for the patient recently or were they experiencing adverse effects of a medication? Is the patient’s cognition at baseline? What are their goals of care and what matters most for their quality of life? Asking these questions can provide important clues that aid with diagnosis and management. 

History should include information from collateral sources, particularly if the patient is cognitively impaired. EMS providers can provide important history including history regarding the patient’s home environment. If the patient presents from a care facility and no representative is available in the ED, documentation and history is often sparse. It is important to call the sending facility to obtain additional information. The patient’s family or support persons are also a valuable source of medical history. They can also provide important information on the patients goals of care. 

As symptoms are often vague, a thorough physical exam is crucial. The patient should be completely undressed to avoid missing important physical exam findings. In a patient with symptoms or signs concerning for sepsis, for example, it is important to completely undress them to visualize the skin for a potential source as decubitus ulcers, foot ulcers, and signs of GU infection are often missed.

Differential Diagnosis

Considering a broad differential diagnosis is critical in the care of older adult patients. Table 2 categorizes the broad range of symptoms that may be indicative of an acute coronary syndrome. Female patients in particular are more likely to present with atypical symptoms other than chest pain, and this can lead to a delay in diagnosis and appropriate care. Atypical symptoms are a significant independent risk factor for in-hospital mortality.

Table 2: Atypical symptoms of acute coronary syndromes
  • Nausea
  • Vomiting
  • Weakness
  • Malaise, “feeling unwell or not right”
  • Fatigue
  • Diaphoresis
  • Shortness of breath
  • Abdominal pain
  • Isolated jaw, shoulder, or abdominal pain
  • Back pain

For patients with abdominal pain, consider both intra and extra-abdominal causes including chest pathology. Referred pain from the chest, genitourinary system, and hips can cause abdominal pain. Older adult patients are at high risk for vascular pathology such as aortic dissection or acute myocardial infarction due to atherosclerosis. Infectious, obstructive, and metabolic etiologies are also important considerations. Table 3 contains a broad differential diagnosis for the geriatric patient with diffuse abdominal pain.

Table 3: Differential Diagnosis for Diffuse Abdominal Pain
  • Aortic aneurysm 
  • Aortic dissection 
  • Acute coronary syndrome
  • Appendicitis
  • Bowel obstruction
  • Cholecystitis
  • Constipation/obstipation
  • Colitis
  • Diverticulitis
  • DKA
  • Malignancy
  • Mesenteric ischemia
  • Pancreatitis
  • Perforated viscus
  • Peritonitis
  • Pneumonia
  • Pulmonary embolism
  • Pyelonephritis
  • Urinary tract infection
  • Volvulus

Diagnostic Testing

Diagnostic testing should be guided by the patient’s history and physical examination findings, but it is wise to cast a wider net with diagnostic testing when symptoms are vague or atypical. 

Initial evaluation for abdominal pain or infectious symptoms includes:

  • Complete blood count with differential
  • Complete metabolic panel
  • Lipase
  • Troponin
  • Lactate
  • Urine analysis
  • Blood cultures
  • ECG

In older adults with chest pain, initial evaluation includes:

  • Complete blood count with differential
  • Basic metabolic panel
  • Troponin
  • Consider D-dimer based on risk stratification tools such as Wells score and clinical gestalt


Point of care ultrasound is a very useful modality for detecting life threats. A FAST (focused assessment with sonography in trauma) exam evaluating for free fluid in the pericardial, peritoneal, and pelvic spaces can rapidly identify internal hemorrhage. The chest can be interrogated with cardiac and IVC windows to assess volume status and provide an estimate of cardiac function. Pulmonary views can also detect pneumothorax, pleural effusions, or pneumonia. 

A STAT chest X-ray can also be obtained to evaluate for free air under the diaphragm in the older adult with abdominal pain. 

The decision to obtain CT imaging is always a risk/benefit analysis. There should be a low threshold to obtain CT imaging in older adults because the risk of radiation-induced malignancy in their lifetime is low and the risk of acute life threatening pathology is high.



When there is concern for infection or sepsis, initiating antibiotics early can improve clinical outcomes. Older adults are particularly vulnerable to adverse effects of medications including antibiotics. Fluoroquinolones, for example, can precipitate delirium, tendinopathy, QT prolongation, and increased risk of aortic pathology and should be reserved for when other antibiotic choices are contraindicated. It is also important to consider how any medications may interact with the patient’s home regimen, such as warfarin. It is important to adequately treat the patient’s pain as well. Geriatric patients are particularly vulnerable to sedation and respiratory depression caused by opioid analgesics due to changes in pharmacokinetics associated with aging and polypharmacy, so reduction in dosing along with frequent reassessment should be considered. 

Specialty Consultation

Laboratory tests and imaging findings help determine which specialty service consultations are indicated.  For example, consultation with General Surgery is indicated in patients with peritoneal signs on exam (rigidity, rebound tenderness, or guarding) or acute surgical findings on CT such as a perforated viscus or appendicitis. Patients who are critically ill or unstable will likely require medical or surgical ICU admission. Social workers and case managers are instrumental in assisting with social aspects of the patient’s care and discharge planning. In critically ill patients who wish to pursue comfort care or a hospice model of care, palliative care consultation can help navigate the patients goals and disposition.

 Pearls and Pitfalls

  • Critical illness often presents atypically in older adults: maintain a high index of suspicion for the critical pathology in the older adult with vague symptoms.
  • Peritoneal signs are often absent in the geriatric acute abdomen due to decreased pain perception.
  • Fever and leukocytosis are often absent in patients with acute infection due to immunosenescence. 
  • A broad differential diagnosis is necessary in older adults due to lack of localizing symptoms.
  • Acute coronary syndromes may present without chest pain, particularly in older adults and female patients.
  • Check the patient’s medication list for beta blockers that blunt tachycardia or other medications that may mask symptoms.
  • Obtain collateral history to guide next steps in management.
  • Establish the patient’s goals of care.
  • Have a low threshold for labs and CT imaging. In geriatric patients with acute abdominal pain, CT is the modality of choice. 
  • Manage and treat pain when appropriate, while being mindful of dose and drug interactions.

Case Study Resolution

The patient is resuscitated with IV fluids with improvement in her blood pressure and broad spectrum antibiotics are initiated. Labs are notable for an elevated lactate of 6.0 mmol/L. STAT chest X-ray demonstrates free air under the diaphragm. Once the patient has been stabilized, a CT of the abdomen and pelvis is obtained that demonstrates perforated diverticulitis. General surgery is consulted and the patient is taken to the OR emergently. After her hospital admission, the patient is able to return to her assisted living facility with physical therapy support.


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  3. Brieger D, Eagle K, Goodman S, et al. Acute coronary syndromes without chest pain, an underdiagnosed and undertreated high-risk group: insights from the Global Registry of Acute Coronary Events. Chest. 2004;126(2):461-469.
  4. El-Menyar A, Zubaid M, Sulaiman K, et al. Atypical presentation of acute coronary syndrome: a significant independent predictor of in-hospital mortality. J Cardiol. 2011;57(2):165-171.
  5. Canto J, Rogers W, Goldberg R, et al. Association of age and sex with myocardial infarction symptom presentation and in-hospital mortality. JAMA. 2012;307(8):813-822.
  6. Institute of Healthcare Improvement . (2019). Age-friendly health systems: Guide to using the 4Ms in the care of older adults. Retrieved August 10th 2021, from