Altered Mental Status in a Patient Transferred From ICU

Case Study

A rapid response event was initiated by a nurse for a patient with altered mental status (AMS). On the arrival of first responders, the patient was agitated and disoriented. The bedside nurse stated that the patient has not been responding to questions appropriately and has been trying to take out her intravenous (IV) catheters and climbing out of bed despite frequent reorientation. Per the report, the patient was an 86-year-old female with a past medical history of chronic obstructive pulmonary disease (COPD), type 2 diabetes mellitus, hypertension (HTN), hyperlipidemia, and hearing loss who was recently transferred to the medical floor following a one-week intensive care unit (ICU) stay for acute on chronic hypercapnic respiratory failure secondary to COPD exacerbation that required intubation. The patient had finished a five-day course of steroids and antibiotics. She was extubated one day prior and had been saturating well on 4 L/min (LPM) O ₂ via nasal cannula. The nurse stated that the patient was transferred from the ICU 1 h prior and was drowsy on arrival; the nurse did not witness any seizure-like activity.

Vital Signs

Temperature: 98.3°F, axillary
Blood Pressure: 134/87 mmHg
Heart Rate: 94 beats per min (bpm)
Respiratory Rate: 16 breaths per min
Pulse Oximetry: 95% oxygen saturation on 4 LPM O ₂via Nasal cannula

Focused Physical Examination

A quick exam revealed an elderly female who was agitated and speaking loudly intermittently. She was unable to answer any questions or follow commands. Her pupils were equal in size and reactive to light. Her pulmonary and cardiovascular exam was unrevealing. Her abdomen was soft and non-tender without any peritoneal signs. Motor testing was unable to be performed. There were no signs of any urinary or bowel incontinence.

Interventions

Due to suspected acute change in mental status, a stat computed tomography (CT) scan of the head was ordered to evaluate for acute intracranial pathologic conditions. Basic laboratory tests were drawn, including bedside blood glucose, basic metabolic profile, and urinalysis. Due to a history of COPD and recent respiratory failure, an arterial blood gas was drawn. All lab results were within expected parameters. CT of the head was negative for any acute pathologic conditions that could explain the patient’s AMS. Due to the low likelihood of seizures (no prior history of seizure, no witnessed seizure activity) or stroke (no focal deficits on the exam), and no other abnormalities found on laboratory or radiological examinations, the most likely diagnosis was hyperactive delirium secondary to a prolonged ICU stay. Due to her agitation being a potential barrier to recovery and her attempts at climbing out of bed posing a fall risk, she was given a small dose of haloperidol.

Final Diagnosis

Mixed delirium, secondary to a prolonged ICU stay.

Delirium

Delirium is an acute change in cognitive function which waxes and wanes throughout the day. According to the Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 , delirium is characterized by:

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Disturbance in attention from baseline.
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Which develops over a short period of time and fluctuates throughout the day.
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With an additional disturbance in cognition.
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The disturbances cannot be explained better by another cause.
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There is evidence that the disturbance is caused by a medical condition, substance intoxication/withdrawal, or medication side effect.

Delirium can be classified as hyperactive, hypoactive, or mixed, as described in Fig. 39.1 . Risk factors for delirium are discussed in Table 39.1 .

Table 39.1

Common risk factors for delirium

Conditions associated with delirium
• Advanced age • Hearing impairment • Inadequate pain control • Sepsis • High-grade fever • Electrolyte imbalance, especially sodium and calcium • Thyroid disorders • Blood glucose derangement • Liver disease • Renal failure	• Hypoxia and hypercapnia • Central nervous system infections • Hospitalization, especially intensive care unit stay • Alcohol use • Medications • Opioids • Sedatives • Antihistamines • Skeletal muscle relaxants • Corticosteroids • Substance abuse