A 35-year-old man is brought to the emergency department due to weakness and lethargy. His friend could not get him out of bed this morning and called emergency medical services (EMS). The patient has a history of injection heroin use, but intramuscular naloxone administered by EMS personnel failed to improve his condition. Temperature is 38.1 C (100.6 F), blood pressure is 110/66 mm Hg, pulse is 104/min, and respirations are 19/min. There is ptosis of both eyes, and the pupils are dilated and sluggish to react. The patient is unable to hold his head up, and respirations are shallow. The lungs are clear on auscultation, and no cardiac murmurs are present. The abdomen is soft and nontender with normal bowel sounds. Two abscesses are present on the left thigh. Arterial blood gases reveal hypoxia and acute respiratory acidosis. The patient is intubated, and mechanical ventilation is begun. Which of the following is the best next step in management of this patient?

Question

A 35-year-old man is brought to the emergency department due to weakness and lethargy.  His friend could not get him out of bed this morning and called emergency medical services (EMS).  The patient has a history of injection heroin use, but intramuscular naloxone administered by EMS personnel failed to improve his condition.  Temperature is 38.1 C (100.6 F), blood pressure is 110/66 mm Hg, pulse is 104/min, and respirations are 19/min.  There is ptosis of both eyes, and the pupils are dilated and sluggish to react.  The patient is unable to hold his head up, and respirations are shallow.  The lungs are clear on auscultation, and no cardiac murmurs are present.  The abdomen is soft and nontender with normal bowel sounds.  Two abscesses are present on the left thigh.  Arterial blood gases reveal hypoxia and acute respiratory acidosis.  The patient is intubated, and mechanical ventilation is begun.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

Explanation: This patient's cranial nerve (CN) palsy (ptosis, dilated pupil), acute hypoxemic respiratory failure, muscle weakness (eg, inability to hold the head up), and cutaneous abscesses raise strong suspicion for wound botulism. Most cases occur when Clostridium botulinum spores contaminate a puncture wound (eg, injection drug use), germinate in the anaerobic environment, and generate botulinum toxin in vivo. Botulism can also occur when spores (infant botulism) or preformed botulinum toxin (foodborne botulism) are ingested. Exposure to botulinum toxin, which impairs the presynaptic release of acetylcholine at the neuromuscular junction, generally results in: presynaptic release Symmetric, descending motor paresis beginning with the CNs; this often includes CN III, CN IV, and CN VI (diplopia, ptosis, mydriasis) and CN IX and CN X (dysphagia, suppressed gag) Progressive respiratory compromise due to diaphragmatic paralysis Autonomic dysfunction (eg, ileus, orthostatic hypotension, urinary retention) Because botulinum toxin targets the motor synapse, sensory abnormalities and confusion are rare (although lethargy from respiratory failure can occur). In contrast to infant or foodborne botulism, wound botulism is often associated with fever and leukocytosis and generally presents ~10 days (rather than within hours) after transmission. Confirmation requires the isolation of C botulinum in culture or identification of toxin in serum. However, urgent treatment with equine botulinum antitoxin is required to prevent progression and should not be delayed for testing in suspected cases. Respiratory support and wound debridement are also often required. (Choices A and D) Opioid intoxication (which can be reversed with the opioid antagonist naloxone) can cause weakness, lethargy, and respiratory failure; however, most patients have bradypnea, and ptosis is uncommon. Therefore, additional naloxone is not required in this patient. Although a drug screen may be helpful in the overall evaluation of this patient given his history of heroin use, it would not alter current management as he requires urgent treatment with antitoxin. (Choice C) Intravenous buprenorphine can be used to treat symptoms of opioid withdrawal, which is usually characterized by flulike symptoms (eg, myalgia, rhinorrhea, diarrhea); cranial nerve palsies and respiratory failure would be atypical. (Choice E) Tetanus is a neuromuscular disease caused by the toxin-producing Clostridium tetani. Risk is increased in those who use intravenous drugs. However, tetanus causes tonic contraction of skeletal muscles (eg, trismus, rigid abdomen) and severe muscle spasms. Educational objective: Wound botulism occurs when Clostridium botulinum spores contaminate a puncture injury (eg, intravenous needle), germinate, and generate neurotoxin in vivo. Manifestations include symmetric, descending neurologic deficits (eg, cranial nerve palsy), respiratory compromise, and autonomic dysfunction. In contrast to foodborne and infant botulism, fever and leukocytosis may be present. Urgent treatment with equine botulinum antitoxin is required and should not be delayed for diagnostic evaluation. References: Wound botulism outbreak among persons who use black tar heroin-San Diego County, California, 2017-2018. (http://www.ncbi.nlm.nih.gov/pubmed/30605447) Outbreak of wound botulism in people who inject drugs, Norway, October to November 2013. (http://www.ncbi.nlm.nih.gov/pubmed/24229788)

A 35-Year-Old Man Is Brought to the Emergency Department Due