In an 83-year-old man four days post‑operative from left hip fracture repair who is now disoriented, febrile, hypertonic, and has brisk reflexes without focal weakness, which is the most urgent next step: bedside swallow evaluation, serum total thyroxine level, non‑contrast head CT, or EEG?

CT Head Without IV Contrast

In this 83-year-old man with multiple high-risk features for intracranial pathology—including recent hip surgery, anticoagulation (Apixaban), new-onset delirium with fever, and hypertonia—you should obtain a non-contrast CT head immediately. 1

Clinical Reasoning

This patient presents with acute altered mental status (disorientation) in the post-operative setting with several red flags that mandate urgent neuroimaging:

High-Risk Features Present

• Anticoagulation therapy (Apixaban): This is one of the strongest predictors of treatment-altering findings on head CT in elderly patients with delirium 1
• Recent falls/trauma risk: Hip fracture patients have documented fall history, and post-operative patients are at risk for unwitnessed falls
• Age >65 years: Independent risk factor for intracranial pathology 1
• History of hypertension: Associated with increased risk of intracranial findings 1
• Vomiting on post-operative day 1: Associated with intracranial pathology 1

Why CT Head is the Priority

The 2024 ACR Appropriateness Criteria explicitly state that non-contrast head CT is the first-line neuroimaging test of choice for altered mental status and can be performed safely and rapidly in all patients 1. While the overall yield of CT in delirium is relatively low (7.4% in patients without focal deficits), the detection of treatment-altering findings becomes significantly higher when risk factors are present—particularly anticoagulation therapy, which this patient is receiving 1.

The critical consideration: Although this patient has no focal motor deficits, the guidelines emphasize that "patients may not have clinical signs on examination that predict a focal pathology" 1. The hypertonia and brisk reflexes, while not classic focal findings, represent neurological changes that warrant investigation. The low diagnostic yield must be weighed against the risk of "possible, preventable morbidity" from missed intracranial hemorrhage, subdural hematoma, or stroke 1.

Why Not the Other Options?

Thyroid Function Testing (Option B)

While this patient has a history of hyperthyroidism treated with radioactive iodine and is on levothyroxine replacement, thyroid dysfunction is not the immediate life-threatening concern. Yes, overt hyperthyroidism increases post-operative complication risk in hip fracture patients 2, but:

• He's already been treated with radioactive iodine (likely now hypothyroid on replacement)
• Thyroid storm would present with tachycardia, hyperthermia (>38°C), and agitation—not the hypertonia and resistance to movement seen here
• Thyroid testing can be sent simultaneously but should not delay neuroimaging

Swallow Evaluation (Option A)

Aspiration pneumonia is a valid concern in post-operative elderly patients with altered mental status, but:

• He has no cough, normal oxygen saturation, and only low-grade fever (38°C)
• The neurological findings (hypertonia, brisk reflexes, disorientation) suggest a primary neurological process rather than aspiration
• Swallow evaluation is appropriate after ruling out intracranial pathology that could be causing the altered mental status

EEG (Option D)

Non-convulsive status epilepticus is in the differential for altered mental status, but:

• The patient is not described as having seizure activity
• EEG is typically a second-line test after initial structural imaging rules out mass lesions, hemorrhage, or stroke 1
• The ACR guidelines recommend CT head first, with EEG reserved for suspected seizure activity 1

Post-Imaging Management

After obtaining the CT head:

• If negative, proceed with comprehensive delirium workup including urinalysis/culture (most common post-operative complication at 12.6% 1), chest X-ray if respiratory symptoms develop, and metabolic panel
• Consider thyroid function tests given his history, though less urgent
• Evaluate for other post-operative complications: cardiac events (8.3% incidence), medication effects (anticholinergics, narcotics), or metabolic derangements 1
• The fever on post-operative day 4 is actually within the normal inflammatory response pattern for hip surgery, which typically peaks on day 1 and normalizes by day 5 3

The key principle: In an anticoagulated elderly patient with new altered mental status and neurological signs, intracranial hemorrhage or other structural pathology must be excluded first, as this represents the most immediately life-threatening and treatable cause of his presentation.