Bradyarrhythmias and heart block

Manage now— do this, in order

• Lie flat, raise the legs, give oxygen and correct hypoxaemia — in children this may be the entire treatment; attach continuous ECG monitoring with a defibrillator and pacing pads at the bedside.Not available at your setup — Defibrillator.
• Correct potassium, magnesium and calcium, and stop the culprit drug (digitalis, verapamil, diltiazem, beta-blockers including glaucoma eye drops, clonidine, amiodarone, ivabradine) — hyperkalaemia with tall tented T waves and broad QRS is treated on the ECG before the result returns.Not available at your setup — Serum electrolytes. No electrolytes available: treat hyperkalaemia on the ECG picture alone.
• Atropine 0.5–0.6 mg IV bolus, repeated every 3–5 minutes to a maximum cumulative 3 mg. Child: 20 microgram/kg IV/IO (minimum single dose 100 microgram, maximum 600 microgram), repeated once, for clearly vagal bradycardia or organophosphate poisoning only.Doctor / Nurse
• Never give a single atropine dose below 0.5 mg — sub-therapeutic doses cause paradoxical vagotonic slowing.
• If atropine fails — infusion: isoprenaline 2 mg in 500 mL 5% dextrose at 10–60 mL/hour (about 0.7–4 microgram/min) or 2–20 microgram/min titrated; or dopamine 5–20 microgram/kg/min IV; or adrenaline 2–10 microgram/min where bradycardic *and* hypotensive. In children adrenaline is first line: 10 microgram/kg IV/IO (0.1 mL/kg of 1:10 000) every 3–5 minutes or 0.05–0.3 microgram/kg/min.Doctor / NurseNot available at your setup — Infusion pump.
• When drugs fail, pace — transcutaneous pacing is the most expeditious technique: demand mode, rate 60–80/min in an adult, output up from zero in 5–10 mA steps until capture plus a safety margin. Confirm capture twice — electrical (spike followed by broad QRS and T wave) and mechanical (femoral or brachial pulse at the paced rate, never the carotid).Doctor / NurseNot available at your setup — Defibrillator. No pacer: percussion pacing — firm rhythmical fist blows over the lower left sternal edge from about 10 cm at 50–70/min — bridges seconds while help is arranged.
• If drugs and pacing all fail, ask what was swallowed: glucagon 5–10 mg IV then 1–5 mg/hour (beta-blocker poisoning); 10% calcium gluconate 10–20 mL IV over 5–10 minutes (calcium-channel blocker); atropine 1.2–2.4 mg IV plus digoxin-Fab (digoxin); atropine 1.2–2.4 mg IV in escalating doses until secretions dry (organophosphate).Doctor / Nurse
• Child: airway, oxygen and ventilation first and usually suffice; if the rate stays below 60/min with poor perfusion despite effective oxygenation and ventilation, start chest compressions; use intraosseous access at the same doses if cannulation fails.
• Never give IV verapamil to a patient on a beta-blocker, and never lower the blood pressure in the Cushing response (bradycardia + hypertension + falling conscious level = raised intracranial pressure — CT head is mandatory).