The Hs and Ts — Reversible causes in pediatric cardiac arrest (Nelson Textbook of Pediatrics 22nd Edition, Chapter 79). Identify and treat to improve ROSC and survival.
🌐 paeds.online — Pakistan's Pediatric Platform| Potentially Reversible Causes of Cardiac Arrest (Hs & Ts) | ||
|---|---|---|
| Cause | Common Clinical Settings | Treatment |
| 🔴 Hypovolemia | Dehydration, hemorrhage, major burns, diarrhea, trauma | Administer fluids (crystalloid, blood products for hemorrhage) |
| 🔴 Hypoxia | Airway obstruction (croup, anaphylaxis, foreign body), parenchymal lung disease, restrictive lung disease | Supplemental oxygen, confirm ETT placement, ensure adequate ventilation, treat underlying cause |
| 🔴 Hydrogen ion (Acidosis) | Preexisting acidosis, diabetes, diarrhea, toxins, prolonged resuscitation, renal disease, shock | Reassess CPR quality, oxygenation, ventilation; correct acidosis with adequate ventilation; consider bicarbonate for severe documented acidosis |
| 🔴 Hypoglycemia | Starvation, toxin (insulin, oral hypoglycemics), diabetes medications, metabolic disease | Administer dextrose (D10W 5-10 mL/kg, D25W 2-4 mL/kg, or glucagon if no IV access) |
| 🔴 Hyperkalemia | Metabolic acidosis, renal failure, tumor lysis, rhabdomyolysis, hemolysis | Stabilize cardiac membrane: calcium; treat acidosis: bicarbonate; shift potassium intracellularly: insulin+glucose, albuterol; promote excretion: loop diuretics, Kayexalate; dialysis |
| 🔴 Hypokalemia | Diabetes, diuretic use, GI losses, toxins | IV potassium replacement (urgent if profound with cardiac arrest) |
| 🔴 Hypothermia | Drowning, exposure, burns, trauma, homelessness | Active internal rewarming (ECMO, warm fluids, warm humidified oxygen); defibrillation may be ineffective until >30°C |
| 🟣 Tension pneumothorax | Procedural complication, mechanical ventilation, trauma, asthma, COPD | Needle decompression (2nd ICS, midclavicular line) followed by chest tube insertion |
| 🟣 Cardiac tamponade | Hemorrhage, malignancy, pericarditis, trauma, post-cardiac surgery | Pericardiocentesis (subxiphoid approach, echo-guided if possible), IV fluids (temporizing) |
| 🟣 Toxins (poisoning/drug overdose) | Alcohol, medications, CO, cyanide, antidepressants, opioids, calcium channel blockers, beta-blockers | Supportive care, antidotes (naloxone, hydroxocobalamin, etc.), consult toxicologist, consider lipid emulsion therapy |
| 🟣 Thrombosis (pulmonary) | Hospitalized patient, recent surgery, known risk factors for VTE, indwelling lines | Fluids, vasopressors, consider thrombolytics (tPA) or mechanical thrombectomy, ECMO |
| 🟣 Thrombosis (coronary) | Congenital heart disease, Kawasaki disease, family history of sudden cardiac death | Fibrinolytics or percutaneous coronary intervention |