Chapter 12. Resuscitation in special circumstances

1. Cardiac Arrest in Pregnancy

Cardiac arrest in pregnancy requires simultaneous maternal and fetal resuscitation.

• Causes: Amniotic fluid embolism, pre-eclampsia, eclampsia, pulmonary embolism, haemorrhage, sepsis.
• Key Modifications to ALS:
  • Manual left uterine displacement: Reduces aortocaval compression to improve venous return.
  • Early intubation and oxygenation: Pregnant women desaturate quickly due to increased oxygen demand.
  • Prepare for perimortem caesarean section (PMCS): If no ROSC within 4 minutes, deliver the baby within 5 minutes.
  • CPR adjustments: Higher hand placement on the sternum due to upward displacement of the diaphragm.
  • Defibrillation is safe: Does not harm the fetus.

2. Trauma-Related Cardiac Arrest

Traumatic cardiac arrest is time-sensitive and requires rapid identification of reversible causes.

• Causes: Hypoxia, tension pneumothorax, cardiac tamponade, haemorrhage, spinal cord injury.
• Key Modifications to ALS:
  • Prioritise treatment of reversible causes: Control bleeding, relieve pneumothorax, treat tamponade.
  • Chest compressions may be ineffective: If hypovolaemia is severe, replacing blood volume is essential.
  • Early intubation and oxygenation: Prevents hypoxia.
  • Use ultrasound (FAST scan) for rapid diagnosis: Identifies tamponade or pneumothorax.
  • Emergency thoracotomy may be needed: Especially in penetrating trauma with signs of life.

3. Drowning and Hypoxia-Induced Cardiac Arrest

Drowning leads to hypoxia, acidosis, and often asystole. The primary focus is on oxygenation.

• Key Modifications to ALS:
  • Early ventilation is critical: Immediate rescue breaths before chest compressions.
  • High-flow oxygen and early intubation: Reduces hypoxic injury.
  • Do not delay CPR for water removal from lungs: Ventilate effectively instead.
  • Monitor for pulmonary oedema: Even if ROSC occurs, secondary lung injury can develop.

4. Anaphylaxis and Cardiac Arrest

Anaphylaxis is a life-threatening allergic reaction causing airway obstruction, hypotension, and cardiac arrest.

• Key Modifications to ALS:
  • IM adrenaline (epinephrine) 500 mcg immediately: Repeat every 5 minutes as needed.
  • IV adrenaline infusion if IM is ineffective: Only for trained providers.
  • Aggressive fluid resuscitation: Anaphylaxis causes massive vasodilation.
  • Antihistamines and steroids: Chlorphenamine and hydrocortisone may help.
  • Nebulised salbutamol: Useful for bronchospasm.

5. Electrocution and Lightning Strikes

Electric shock can cause ventricular fibrillation (VF) or asystole.

• Key Modifications to ALS:
  • VF is common – defibrillate early.
  • Prolonged resuscitation may be needed: There have been successful recoveries after long CPR durations.
  • Assess for burns and internal injuries: Electrical injuries can cause hidden deep tissue damage.
  • Airway oedema can develop – consider early intubation.

6. Hypothermia and Cardiac Arrest

Cardiac arrest due to hypothermia has a better prognosis with prolonged CPR.

• Key Modifications to ALS:
  • CPR and defibrillation may be ineffective until rewarming.
  • Delay adrenaline administration until core temperature is >30°C.
  • Active rewarming is essential: Use warmed IV fluids, blankets, and extracorporeal warming if needed.
  • Do not declare death until the patient is rewarmed: Hypothermic patients can have prolonged survival despite appearing lifeless.

7. Poisoning and Drug Overdose

Toxins can cause cardiac arrest due to arrhythmias, respiratory depression, or acidosis.

• Key Modifications to ALS:
  • Activated charcoal for early ingestions.
  • Lipid emulsion therapy for local anaesthetic toxicity.
  • Specific antidotes where available (e.g., naloxone for opioids, sodium bicarbonate for tricyclic antidepressants).
  • Correct electrolyte imbalances: Some toxins cause hypokalaemia or acidosis.
  • Prolonged resuscitation may be required: Some toxins prolong cardiac arrest without immediate tissue death.

8. Sepsis and Cardiac Arrest

Sepsis can cause cardiac arrest due to multi-organ failure, severe hypotension, and acidosis.

• Key Modifications to ALS:
  • Early aggressive fluid resuscitation: Septic shock causes vasodilation.
  • IV antibiotics ASAP: Treat the underlying infection.
  • Consider noradrenaline infusion: If fluids fail to maintain BP.
  • Correct metabolic acidosis: Sodium bicarbonate may be needed in severe cases.
  • Monitor for disseminated intravascular coagulation (DIC): Sepsis can cause widespread clotting disorders.

9. Cardiac Arrest in the Perioperative Setting

Cardiac arrest during surgery requires coordination between anaesthetists, surgeons, and resuscitation teams.

• Key Modifications to ALS:
  • If in prone position, CPR may be possible with sternal counter-pressure.
  • Identify and treat anaesthetic-related complications (e.g., malignant hyperthermia).
  • Surgical chest compressions may be required in open-chest procedures.
  • Adrenaline should be given in small doses (50-100 mcg IV) rather than the standard 1 mg bolus.

10. Hyperkalaemia and Electrolyte Disorders

Severe hyperkalaemia (>6.5 mmol/L) can cause arrhythmias and cardiac arrest.

• Key Modifications to ALS:
  • Calcium gluconate 10 mL IV: Stabilises cardiac membranes.
  • Insulin + glucose infusion: Shifts potassium into cells.
  • Sodium bicarbonate IV: If acidosis is present.
  • Dialysis may be required for refractory cases.