Rosen & Barkin's 5-Minute Emergency Medicine Consult (787 page)

DIAGNOSIS

• Benzodiazepines and barbiturates:
  
  • Anxiety
    
  • Agitation
    
  • Irritability
    
  • Tremor
    
  • Sleep disturbance
    
  • Tachycardia
    
  • Hypertension
    
  • Hyperthermia
    
  • Autonomic instability
    
  • Seizures
    
• Opiates:
  
  • Restlessness
    
  • Irritability
    
  • Drug craving
    
  • Yawning
    
  • Piloerection
    
  • Mydriasis
    
  • Nausea
    
  • Vomiting
    
  • Diarrhea
    
  • Abdominal pain
    
  • Tachycardia
    
  • HTN
    
• Cocaine:
  
  • Depressed mood
    
  • Fatigue
    
  • Vivid dreams
    
  • Sleep disturbance
    
  • Psychomotor retardation or agitation
    
• Amphetamines:
  
  • Fatigue
    
  • Irritability
    
  • Sleep disturbance
    
  • Anxiety
    

• Obtain substance abuse history
  
  • Time of last substance use
    
  • History of previous withdrawal
    

A thorough physical exam is necessary

Thorough history and physical exam with attention to the vital signs

• Electrolytes, BUN, creatinine, glucose
  
• CBC
  
• Urine drug screening rarely alters management
  

If the clinical situation is not straightforward for withdrawal, CNS or plain radiograph imaging may be indicated depending on the clinical presentation.

• Ethanol withdrawal
  
• Intracerebral hemorrhage
  
• CNS infection
  
• Encephalopathy
  
• Hypoglycemia
  
• Hyperthyroidism
  
• Sepsis
  
• Psychosis
  
• Electrolyte disorder
  
• Drug intoxication
  

TREATMENT

• Assess vital signs
  
• Assess capillary glucose
  

• Attention to ABCs
  
• Obtain IV access
  
• IV fluid administration
  
• Cardiopulmonary monitoring
  

• Benzodiazepine and barbiturate withdrawal:
  
  • Aggressive supportive care
    
  • Begin long-acting agent of the same class causing the withdrawal
    
• Opiate withdrawal:
  
  • Supportive care
    
  • Antiemetics for nausea and vomiting
    
  • Clonidine to reduce severity of signs and symptoms
    
  • Opiate therapy if withdrawal is complicating other disease states
    
• Cocaine and amphetamine withdrawal:
  
  • Supportive care
    

• Clonidine: 0.1–0.3 mg PO q4–6h
  
• Diazepam: 5–20 mg PO for mild signs and symptoms; 5–10 mg IV in repeated doses as necessary for severe symptoms and signs
  
• Lorazepam: 1–2 mg PO for mild symptoms and signs; 2 mg IV in repeated doses as necessary for severe symptoms and signs
  
• Phenobarbital: 30–60 mg PO for mild symptoms and signs; 15–20 mg/kg slow IV administration for severe symptoms or status epilepticus.
  
• Ondansetron: 4–8 mg PO/IV
  

FOLLOW-UP

• Moderate-to-severe withdrawal symptoms
  
• Persistent withdrawal symptoms
  
• Psychosis with withdrawal
  
• Autonomic instability
  
• Concomitant medical condition that may complicate withdrawal
  
• Suicidal ideation or otherwise psychiatrically unstable
  

• Mild symptoms responsive to therapy
  
• Psychiatrically stable
  

Referral to detox program or facility

• Misdiagnosis of medical disease as withdrawal syndrome
  
• Misunderstanding the relationship between withdrawal syndromes and comorbid medical illness
  
• Important to administer sufficient quantities of benzodiazepines for patient in benzodiazepine withdrawal states.
  

• Hamilton RJ. Withdrawal principles. In: Nelson LS, ed.
  Goldfrank’s Toxicologic Emergencies
  . 9th ed. New York, NY: McGraw-Hill, 2010.
  
• Leikin JB. Substance-related disorders in adults.
  Dis Mon
  . 2007;53(6):313–335.
  
• Tetrault JM, O’Connor PG. Substance abuse and withdrawal in the critical care setting.
  Crit Care Clin
  . 2008;24:767–788.
  

CODES

292.0 Drug withdrawal

BASICS

• Syndrome resulting from the presence of an abnormal (accessory) pathway that bypasses the AV node (Kent bundles) between the atria and ventricles
  
• Wolff–Parkinson–White (WPW) pattern on the ECG is defined by a short PR interval and a Δ-wave reflecting early conduction (pre-excitation):
  
  • Accessory pathways occur in 0.1–0.3% of the population.
    
• WPW syndrome requires ECG evidence of the accessory pathway and related tachycardia.
  
• Accessory pathways:
  
  • Small bands of tissue that failed to separate during development:
    
    • Left lateral (free wall) accessory pathway: Most common
      
    • The posteroseptal region of the AV groove: 2nd most common location
      
    • Right free wall
      
    • Anteroseptal
      
• Conduction in WPW may be antegrade, retrograde, or both.
  
• Orthodromic re-entrant tachycardia is the most common (70%):
  
  • Impulse travels antegrade from the atria down the AV node to the ventricle and then retrograde up the accessory pathway.
    
  • This re-entrant tachycardia is a narrow complex rhythm unless a bundle branch block or intraventricular conduction delay is present.
    
• Antidromic is less common (30%):
  
  • Impulse travels antegrade down the accessory pathway and retrograde through the AV node resulting in a wide quasi-random signal (QRS) complex.
    
• Sudden death occurs in 1 per 1,000 patient-years in persons with known ventricular pre-excitation.
  

• Idiopathic:
  
  • Unknown mechanism in most cases, with familial predisposition
    
• Rarely inherited as an autosomal dominant trait
  
• Associated in rare cases with a familial hypertrophic cardiomyopathy
  

DIAGNOSIS

• Asymptomatic
  
• Palpitations:
  
  • Fast or irregular
    
• Chest pain
  
• Dyspnea
  
• Dizziness
  
• Diaphoresis
  
• Syncope
  
• Sudden death (rare)