RSI 2011 update Baha Hamdi, MD

In 1979, Tryle and colleagues, called for improved training in ETI outside OR. Introduced in the early 1980s, Walls and Murphy described the 7 Ps in their ‘Manual of Emergency airway management’.

1- preparation Primary and secondary setup -ET Tube lubrication ? : easier (Expert opinion)

2-preoxygenation 100% O2 by BVM for 2-3 min, gives O2 reservoir for 8 min before Sat. drops to < 90%. This is not 100% true in : -Pre-existing conditions (P.edema, COPD..) -Children (↓FRC) -Obese patients (↓FRC) -Pregnant women (↓FRC) Is this true ?

3-Pretreatment A common practice, Drugs administrated before hypnotic & paralysis. To overcome the adverse effect of: -The laryngoscope and -The RSI drugs. Why ?

More details: In 1951, kings described that stretching of the hypopharynex causes a pressor response mediated by SNS leads to ↑HR, ↑ BP, ↑ risk of arrhythmias. In children PSNS responses can lead to Bradycardia or bronchospasm. Usually transient, and clinical significance is poorly defined. Scolin linked to ↑ICP in animals and bradycardia. Scolin →fasculation which suggested to cause ↑ ICP, ↑ IOP and ↑ IGP

Pretreatment : defasculation Defasculation: small dose(1/10 th ) of ND-NMBA -Few data to support this -Experts do not recommend it in ER (↑ steps &↑ risk of med. errors)

Pretreatment : Fentanyl Blunting, Could be beneficial in selected patients (IHD,GVD, Aneurysm, ICH). - SLR, A transient compensatory physiologic response. -Any hypnotic and sedative in ↑ dose can do, but it will cause↓ BP, Fentanyl was found to do this at doses as low as 2mcg/kg. Why Fentanyl ? Is it useful ?

Pretreatment : Lidocaine Used in RSI in patients with ↑ ICP Data support that it 1.5 mg/kg ↓ cough reflexes Less reliable data to support that it ↓ ICP No quality conclusive data. Recommendation: Experts recommend to use it in ↑ ICP.

Pretreatment : Atropine Routinely used in children. Thought to help in PSR & scolin bradycardia. Data ? No strong data to support this in children or adults. Conflicting data for its use in neonates. Atropine should be used after a 1 st or 2 nd scolin dose if bradycardia developed.

4-Paralysis with Induction: Etomidate ↓ Level of cortisol & aldosterone production. Jaber et al. : comparing to Ketamin: adrenal insufficiency in Etomidate group but no difference in organ failure score or M/M. The effect is detected by ACTH stimulation test, but the clinical significant still debated. The frequency & the effect could be more in sepsis. Only one study by Cuthbertson et al. showed ↑ mortality in sepsis patient. was not proven by similar studies. In 2007 Ray et al. concluded that Etomidate Did not produce worse clinical outcome in septic pt, and could be beneficial because of its excellent CV profile. Conclusion: its clear it cause adrenal depression in response to ACTH, but clinical out come is unchanged comparing with other induction agents.

4-Paralysis with Induction: succinylcoline-ICP A study by Halldin in 1959, started the idea of scolin leads to ↑ ICP. Other studies (Cottrell 1983, Minton 1986) showed the same. in 1994, Kovarick could not report the same effect. Review of +ve studies reveals it were conducted in non human subjects &/or small sizes, mostly with compromised CNS, with very transient effect and with no/little discussion of clinical outcome.

4-Paralysis with Induction: succinylcoline-K Lifethreatining hyperkalemia in certain conditions. Some recommended to avoid scolin after trauma, burn and critical illness. New data suggest that ↑K takes several days. 9 days in burn 10 d in UMN lesion 4 d in PN lesion 21 d in Spinal injury 7 d in sepsis or neuropathies. Thus need not to be avoided.

4-Paralysis with Induction: Medazolam Frequently used as hypnotic in RSI. Sivilotti et al.: less optimal for RSI. Dose ? Sagarin et al. showed that its usually under dosed as mg/kg. According to Caro 2008, the dose for induction should be mg/kg.

5-Positionong: Cricoid pressure Described by Brian Sellick in 1961 to prevent regurgitation, ( 3 out of26 pt, had immediate reflux when CP was releases). Small number of pt. – old anesthesia techniques. 2 Canadian papers: meta-analysis by Briacombe 1997 and Smith 2003: -ve results in RSI. Walls 2008 : CP Potential to worsen laryngoscopic view. Lacks strong evidence to support its routine use.

conclusion CP: not supported Pretreatment with Atropine as defasciculating should be abandoned outside OR. Lidocaine for ICP and Fentanyle for SR are recommended. Avoiding scoline because ICP is not true. Medazolam is a poor induction agent. Propofol is useful in pregnancy. Etomedate is safe even in septic shock

Thank you