A Review of Rapid Sequence Intubation Scott Bouton

A Review of Rapid Sequence Intubation Scott Bouton, M. D.

Principles of RSI • RSI is a process designed to rapidly gain control of an airway in patients who require timely intubation without the benefit of prior patient planning and preparation. • Utilizes medications to rapidly induce unconsciousness and paralysis while at the same time blunting or avoiding some of the undesirable physiologic responses to ETI. • Incorporates pre oxygenation with minimal to no positive pressure ventilation and cricoid pressure (Sellick maneuver) to minimize the chance of aspiration – Sellick / Cricoid pressure is controversial (more in a min) • * RSI is not necessary for intubation in cardiac arrest or comatose patients / without a gag reflex

Potential Risks and Pitfalls

Potential Risks and Pitfalls • Aspiration – – patients requiring emergency intubation must be assumed to have a full stomach, and are therefore at a much higher risk of aspiration. – Patients frequently also have complicating variables such as oral, facial or neck trauma. • Increased ICP – Can result from pain, agitation, gagging or retching during laryngoscope use and ETT placement if not properly medicated. – Problematic especially in those with underlying head trauma. • Secondary Cervical Spine Injury – – in those with underlying C-spine injury

More Risks and Pitfalls

More Risks and Pitfalls • Hypoxemia all patients requiring RSI are under tremendous physiologic stress. – lessens their oxygen reserve – shortens the time required to become hypoxemic. – Children have an even higher metabolic O 2 demand compared to adults and thus desaturate quickly. • Cardiac Instability – – can result from medications – More common in children due to the potential for rapid progression of hypoxemia.

Initial Assessment & Preparation • History – if time allows focus on allergies, underlying medical problems, and the immediate circumstances which led to the patients condition (sepsis, head trauma, asthma, etc. ) • PE – Focus on factors which may complicate intubation (facial or neck trauma, congenital facial anomalies, etc. ) • Assemble all supplies (Bag and mask, ETT’s, suction, stylets, O 2, Drugs, etc. )

Initial Assessment & Preparation • Positioning • Sniffing Position – – – external auditory meatus (ear) level w/ sternal notch. Overextension can occlude visualization of infants airway (big tounge / oral ratio) Towel under infants shoulders (raise chest) due to large occiput Can exacerbate aupper Cspine injuries • Jaw Thrust / Chin Lift – Can exacerbate lower Cspine injuries (even with rigid collar use) • In Trauma / Cspine injury – use in line immobilization, position patient close to head of bed, raise bed to waist level (or higher)

Preintubation Therapy • Preoxygenate as early as possible. This fills lungs with 100% O 2 by washing out nitrogen, and allows patient to tolerate a longer period of apnea without hypoxia. • Avoid BMV (if possible) as this distends the stomach and potentiates vomiting and aspiration. Consider NGT or OGT placement BMV is required

Endotracheal Tubes • Cuffed ETT’s are appropriate in any age (except newborn) – Shown to decrease aspiration risk (after intubation) – Better air seal for PPV – “new” low pressure tubes do not cause increased tracheal injury or swelling / extubation stridor • Uncuffed ETT’s can (also) be used < 8 yrs old due to seal formed by funnel shaped sub glottis. • ETT size = Age (yrs) + 16 / 4 • Proper depth = 3 x ETT size

Medications • Atropine can be used in children < 5 yrs – used to reduce airway secretions and prevent vagal mediated bradycardia (ideally 3 -5 min before ETI) • Lidocaine can be used if increased ICP to blunt effects of laryngoscopy on ICP (ideally 5 min before ETI).

Sedative / Hypnotics • Midazolam (versed) – short acting – anticonvulsant and amnestic properties – Minimal cardiovascular effects. • Etomidate . – rapid onset short acting – – No significant cardiovascular or respiratory depression. Can cause vomiting and myoclonus if not paralyzed Decreases ICP (at least equal to lidocaine) Can suppress cortisol synthesis in one dose (tx with corticosteroids)

Sedative / Hypnotics • Thiopental – – – • Propafol – – – • Rapid acting Anticonvulsant properties. Decreases ICP Myocardial depression Can potentiate hypotension (vasodilator) if volume depleted or in shock. Can induce histamine mediated bronchospasm rapid onset, short acting. Prone to causing hypotension and myocardial depression. Minimal respiratory depression. Ketamine – – rapid acting sedative / analgesic. Sympathomimetic Agent: Bronchodilates, stabilized BP, increases ICP.

Paralytics • Nondepolarizing agents (vecuroneum, rocuroneum) – – competitive antagonists of Ach at the NMJ. Bind to nicotinic receptors and blocks binding of acetylcholine. Does not stimulate ion channel opening. Diffuses away and metabolized by liver, ending neuromuscular blockade. • Depolarizing agents (succinylcholine) – – – competitive agonist of Ach at the NMJ Binds and stimulates nicotinic receptor causing initial fasciculations prolonged receptor binding blocks further stimulation by acetylcholine causing flaccid paralysis. Broken down by cholinesterase. Fasciculations and the associated muscular pain can be avoided (if time allows) by premedicating with a small (1/10) dose of a nondepolarizing agent.

Depolarizing agent • Succinylcholine – fast acting (<1 min), short duration (3 -10 min). – 1 – 2 mg/kg/dose – Can cause parasympathetic mediated bradyarrhythmias and asystole in infants and young children (premedicate w/ atropine). – Can cause sympathetic stimulation in older children resulting in tachycardia and HTN – Can induce malignant hyperthermia (tx with dantroline) – Can increase K+ (avoid in burns, crush injury etc. ) – Can increase ICP and intraoccular pressure

Nondepolarizing Agents • Vecuroneum (Norcuron) – Long onset (1 -2 min), long duration (> 20 min) – 0. 1 – 0. 2 mg/kg/dose IV • Rocuroneum (Zemuron) – – – Rapid Acting (< 1 min), shorter duration (approx 20 min) Can be used to intubate anyone, relative lack of contraindications RSI paralytic of choice 1 - 1. 2 mg/kg/dose 2 mg/kg IM if IV not available in time

Tracheal Manipulation • Sellick Maneuver (Cricoid Pressure) – Currently there is insufficient evidence to recommend routine use • Can potentially cause Tracheal Rupture or obscure the airway if done too forcefully (…inexperienced providers? ? ? ) • Can also potentially cause esophageal rupture in patients who are actively vomiting (…. . Paralytic? ? ? ) – Consider Using (gently / properly) • To prevent passive regurgitation of stomach contents in paralyzed patients – * Especially if BMV required • To aid in visualization of cords – No compelling data against proper use …. Only “isufficient evidence to recommend routine use” (remember PALS Class target audience… community hospitals, EMS, etc. ) – “Cricoid Pressure should be used after a thorough evaluation of the risks and benefits”

Tracheal Manipulation • ELM (external Laryngeal Manipulation) BURP Maneuver – Aids in glottis visualization B – back (towards the spine) U – up (towards the head) R P– rightward pressure * With finger (laryngoscope hand) - Push thyroid cartillage slightly down, Pull towards patients right shoulder

Proposals for Special situations • Head injury (increased ICP) – Lidocaine (dec ICP) – Etomidate (dec ICP) – Rocuroneum (no cardiovascular effects to decrease cerebral perfusion pressure) • Asthma – Ketamine (bronchodilator) – Rocuroneum • Status Epilepticus – Versed (anti convulsant) – Rocuroneum • Sepsis / Hypotension – Ketamine (sympathomimetic, cardiovascular stabilizer) – Rocuroneum (no cardio effects)

Questions?