Rosen & Barkin's 5-Minute Emergency Medicine Consult (125 page)

986 Toxic effect of carbon monoxide

BASICS

• Sudden cardiac arrest is characterized by:
  
  • Unresponsiveness
    
  • Pulselessness
    
  • Little to no respiratory effort
    
• Factors affecting survival:
  
  • Initial rhythm
    
  • Total down time
    
  • Time to successful defibrillation (as indicated)
    
  • Time to basic life-support interventions
    

Contributing factors to cardiac arrest are outlined by the American Heart Association as:

• Hypovolemia
  
• Hypoxia
  
• Hydrogen ion (acidosis)
  
• Hypo-/hyperkalemia
  
• Hypothermia
  
• Toxins
  
• Tamponade, cardiac
  
• Tension pneumothorax
  
• Thrombosis
  
• Trauma
  

• Sudden cardiac arrest in children is often of a respiratory rather than cardiac etiology
  
• Follow current ACLS guidelines for pediatric cardiac arrest. Major differences between adult and pediatric cardiac arrest management include:
  
  • Depth of compressions for pediatric populations should be ∼1/3 to 1/2 the depth of the chest
    
  • For 2 rescuer CPR, a 15:2 compression to ventilation rate is recommended
    
  • Drug dosage differences: See “Medications” section
    

Follow current ACLS guidelines for management of the pregnant cardiac arrest patient:

• Awareness that airway may be difficult
  
• Compressions should be performed at a higher location than conventional CPR, slightly above the center of the sternum
  
• Follow Adult ACLS guidelines for defibrillation
  
• Pre- or postcardiac arrest pregnant patients should be placed in the left lateral recumbent position; during arrest, perform manual left uterine displacement
  
• To ensure a best possible outcome for the fetus, all efforts must be geared toward maternal survival
  
• In the event of a failed maternal resuscitation, an emergent cesarean delivery may be considered
  

DIAGNOSIS

• Unresponsiveness
  
• Pulselessness
  
• Shallow, gasping respirations may persist for a few minutes
  
• Occasionally preceded by:
  
  • Chest pain
    
  • Dyspnea
    
  • Palpitations
    
  • Seizure activity
    
• Immediately prior to arrest:
  
  • Shock or hypotension
    
  • Impaired mentation
    

• Assess circulation, airway, breathing
  
• Determine shockable vs. nonshockable rhythm and treat accordingly, per ACLS guidelines
  

Indicated only when successful return of spontaneous circulation (ROSC) is achieved:

• Electrolytes
  
• BUN/creatinine
  
• Creatinine kinase with isoenzymes, cardiac troponin
  
• ABG
  
• CBC
  
• Therapeutic drug levels
  
• Toxicologic testing
  
• Lactic acid levels
  

• EKG:
  
  • Evaluate for STEMI or ACS
    
• CXR:
  
  • Endotracheal tube position
    
  • Pneumothorax
    
  • Pulmonary etiology of arrest
    
• Echocardiogram:
  
  • Pericardial effusion
    
  • Wall motion abnormality
    
  • Valvular dysfunction
    
• Head CT scan (postresuscitation):
  
  • Rule out bleed/neurologic source
    

• Suspected cardiac etiology:
  
  • Cardiac catheterization lab
    
  • Possible cardiac output augmentation device placement
    
• EEG (postresuscitation)
  
  • Identify and treat seizures
    

Sudden loss of consciousness with a palpable pulse:

• Syncope
  
• Seizure
  
• Acute stroke
  
• Hypoglycemia
  
• Acute airway obstruction
  
• Head trauma
  
• Toxins
  

TREATMENT

• Prompt initiation of standard CPR
  
• Confirm underlying rhythm
  
• Early defibrillation of pulseless ventricular tachycardia (VT) or ventricular fibrillation (VF)
  
• Secure airway and provide adequate respirations. Advanced airway should be deferred if placement interrupts BLS measures
  
• Postresuscitation care:
  
  • Identify cause of arrest
    
  • 12-lead EKG
    
  • Monitor vital signs
    
  • Fluid bolus and/or vasopressors for hypotension
    
• Transport to the closest facility that is capable of handling postarrest patients:
  
  • Consider transport to center equipped for interventional cardiac care and those specializing in postarrest care
    
  • Pediatric critical care center for children
    

• Initiate ACLS
  
• Perform standard CPR as long as no pulse is palpable:
  
  • Stop CPR only briefly to check pulse, cardiac rhythm, or defibrillate
    
• Secure the airway
  
• Obtain IV/IO access
  
• Cardiac monitor
  
• Therapy is based on the underlying rhythm, according to ACLS protocols
  

• Pulseless VT or VF:
  
  • Immediate defibrillation with 1 countershock:
    
    • Energy selection based on type of defibrillator for biphasic (if unknown use 200 J) or 360 J monophasic
      
  • If defibrillation is unsuccessful, continue CPR for 2 min and re-evaluate rhythm. When IV/IO access is established, and after second rhythm check then consider:
    
    • Epinephrine
      
    • Vasopressin
      
  • If refractory to defibrillation and epinephrine, consider:
    
    • Amiodarone
      
    • Lidocaine
      
    • Magnesium for
      torsade de pointes
      
• Asystole:
  
  • Confirm in ≥2 leads
    
  • Epinephrine
    
  • May substitute vasopressin to replace 1st or 2nd dose of epinephrine
    
• Pulseless electrical activity:
  
  • Epinephrine
    
  • Treat for reversible cause of pulseless electrical activity/asystole
    
• Postresuscitation:
  
  • Treat the underlying cause of the arrest.
    
  • EKG to establish presence of acute coronary syndrome:
    
    • Immediate catheterization for STEMI
      
    • Consider catheterization for suspected cardiac etiology without STEMI
      
  • Ventilatory support
    
  • Correct electrolyte abnormalities
    
  • Initiate volume resuscitation and provide vasopressors/inotropic support as needed
    
  • Targeted temperature management for eligible patients
    
  • Continuous EEG to rule out seizures
    

Medication administration should never interrupt CPR:

• Amiodarone: 300 mg (peds: 5 mg/kg to max. 15 mg/kg) IVP
  
• Epinephrine: 1 mg (peds: 0.01 mg/kg) IVP q3–5min
  
• Lidocaine: 1–1.5 mg/kg 1st dose (peds 1 mg/kg) IVP, then 0.5–0.75 mg/kg (peds: 20–50 μg/min) IV, up to 3 mg/kg
  
• Magnesium: 1–2 g (peds: 25–50 mg/kg max. of 2 g) slow IV
  
• Vasopressin: 40 U IVP (as replacement for dose 1 or 2 of epinephrine in adult arrest)
  
• Sodium bicarbonate: 1 mEq/kg (peds: 1 mEq/kg) slow
  

FOLLOW-UP

ROSC:

• Intensive care unit
  
• Postresuscitation care
  
• Treatment of underlying cause of arrest