A 46-year-old hospitalized man is evaluated for confusion. He was admitted 3 days ago after a motor vehicle collision in which he was a passenger. He sustained fractures of the right tibia and fibula, which were surgically reduced and fixed. The patient had a small subdural hematoma without midline shift, which was managed nonoperatively. He has been receiving intravenous morphine for pain control. This morning, the patient was agitated and disruptive and was talking to persons who were not there. He has no significant medical history and takes no regular medications. Temperature is 37.5 C (99.5 F), blood pressure is 170/100 mm Hg, pulse is 120/min and regular, and respirations are 22/min. Pulse oximetry shows 96% on room air. The patient appears diaphoretic and tremulous and is trying to pull out the intravenous lines. He is not cooperative for funduscopic examination, but pupils are equal and reactive bilaterally. Breath sounds are normal and no heart murmurs are heard. The abdomen is soft and nontender. The surgical incision shows no surrounding erythema. The patient moves all extremities without limitations. Which of the following is the most likely cause of this patient's acute confusion?

Question

A 46-year-old hospitalized man is evaluated for confusion.  He was admitted 3 days ago after a motor vehicle collision in which he was a passenger.  He sustained fractures of the right tibia and fibula, which were surgically reduced and fixed.  The patient had a small subdural hematoma without midline shift, which was managed nonoperatively.  He has been receiving intravenous morphine for pain control.  This morning, the patient was agitated and disruptive and was talking to persons who were not there.  He has no significant medical history and takes no regular medications.  Temperature is 37.5 C (99.5 F), blood pressure is 170/100 mm Hg, pulse is 120/min and regular, and respirations are 22/min.  Pulse oximetry shows 96% on room air.  The patient appears diaphoretic and tremulous and is trying to pull out the intravenous lines.  He is not cooperative for funduscopic examination, but pupils are equal and reactive bilaterally.  Breath sounds are normal and no heart murmurs are heard.  The abdomen is soft and nontender.  The surgical incision shows no surrounding erythema.  The patient moves all extremities without limitations.  Which of the following is the most likely cause of this patient's acute confusion?

Quizplus · Accepted Answer

Explanation: 11ec25c8_d88a_baa8_bc81_bf49323cdf32_MD0003_00 In a patient who has been hospitalized for 72 hours, the onset of acute change in cognition and attention, tachycardia, hypertension, tremulousness, diaphoresis, agitation, and hallucinations should raise suspicion for delirium tremens (DT) due to alcohol withdrawal. Chronic alcohol use results in insensitivity to GABA, the neurotransmitter principally responsible for maintaining inhibitory tone. In contrast, a prolonged decrease in or cessation of alcohol intake leads to disequilibrium between inhibition and excitation, favoring excitation of the central, somatic, and autonomic nervous systems. A history of alcohol consumption may go undetected in patients who have trauma or encephalopathy. Manifestations of withdrawal may be mistaken for symptoms of the concurrent condition or surgery. These manifestations vary based on quantity, duration, and time since the last drink and may include: Early withdrawal (6-36 hours) - tremor, anxiety, headache, normal sensorium Neuropsychiatric (12-48 hours) - generalized seizures, hallucinations DT (48-96 hours) - altered sensorium, agitation, tremor, autonomic instability Management of DT includes ruling out other causes of delirium, providing nutritional and electrolyte supplementation, and administering benzodiazepines. (Choice B) Elevated intracranial pressure usually manifests with lethargy or obtundation, pupillary abnormalities (eg, enlarged, asymmetric, nonreactive), and Cushing response (eg, hypertension, bradycardia, respiratory depression). Although this patient has a subdural hematoma, he has normal, reactive pupils and is agitated and tachycardic. (Choice C) Fat embolism syndrome occurs 1-3 days following a traumatic injury with the triad of petechiae, pulmonary infiltrates with hypoxia, and altered mentation. This patient has only altered mentation. (Choice D) Malignant hyperthermia is an autosomal dominant disorder of skeletal muscle hypermetabolism that leads to hyperpyrexia, muscle rigidity and breakdown, and respiratory and metabolic acidosis. It occurs rarely and usually only perioperatively with exposure to volatile anesthetics and/or succinylcholine. (Choice E) Neuroleptic malignant syndrome is a reaction to neuroleptic medications (eg, haloperidol, fluphenazine) that results in severe ("lead pipe") muscle rigidity, hyperthermia, delirium, and autonomic instability. This patient is not on neuroleptic medication and does not have a fever. (Choice F) Opiate intoxication leads to lethargy, constricted pupils, and respiratory depression. (Choice G) Pulmonary embolism is a potential postoperative complication usually presenting with chest pain, dyspnea, hypoxia, tachycardia, and diaphoresis. Delirium and agitation would be an uncommon presentation, but this patient is not hypoxemic. Educational objective: Delirium tremens is a severe manifestation of alcohol withdrawal usually presenting 48-96 hours after the last drink. It is defined by autonomic excitation, agitation, tremor, and altered sensorium. References: Management of drug and alcohol withdrawal. (http://www.ncbi.nlm.nih.gov/pubmed/12724485)

A 46-Year-Old Hospitalized Man Is Evaluated for Confusion