Vasoactive drugs & electrolytes - relevance to airway management and intubation
Airway interventions and endotracheal intubation commonly precipitate haemodynamic instability.
Induction agents, transition to positive‑pressure ventilation, airway stimulation and pre‑existing shock states (sepsis, hypovolaemia, cardiogenic shock, anaphylaxis, right‑ventricular failure) can all cause sudden drops in blood pressure and cardiac output.
Anticipation, preparation and timely use of vasoactive drugs - together with rapid recognition and correction of life‑threatening electrolyte disturbances - are therefore essential for safe peri‑intubation care in the ED.
This section gives a practical, exam‑relevant summary of:
- the physiology of peri‑intubation collapse
- practical pharmacology and clinical roles of common vasoactive agents
- agent selection, haemodynamic targets and routes of administration (peripheral vs central) in line with UK guidance (NICE, Resuscitation Council UK)
- a rapid ED checklist plus an electrolyte quick‑reference for hyperkalaemia and hypokalaemia
Where specific infusion concentrations or exact dosing are required, follow local trust protocols and pump guidelines.
Why patients collapse at induction
- Induction agents and neuromuscular blockade reduce sympathetic tone and myocardial contractility, and vasodilate peripheral vessels.
- Positive‑pressure ventilation reduces venous return, markedly in hypovolaemia or RV‑dependent circulation, lowering preload and cardiac output.
- Autonomic responses to laryngoscopy (sympathetic surge then vagal tone) can cause transient hypertension followed by bradycardia and hypotension.