Etomidate

[kohlerrf]

The potency of morphine versus fentanyl is not really relevant: you simply need to give an equivalant dose of morphine to achieve the same effect as the dose of fentanyl you would normally give. However fentanyl has a quicker onset and is indeed less likely to cause hypotension as it does not have the propensity to cause histamine release that morphine has.

An opioid is a vital part of the induction process for drug assisted intubation. Laryngoscopy and intubation causes a rise in ICP due to sympathetic stimulation. This is exactly what we want to avoid when we are intubating someone whom we believe to have issues with their ICP already (TBI, intra-cranial bleed and so on) Fentanyl (as the usual dug of choice) blunts sympathetic response to the procedure and at high enough doses will completely eliminate any sympathetic response. It seems bizarre that you would premedicate with lidocaine which has no proven role in the management of ICP during RSI, yet not give a drug that does have an accepted role.

Midazolam most certainly does have a significant effect on vasomotor tone and is well known to cause (usually transient) hypotension following bolus doses, probably through it's effect on the synthesis of prostanoids. Loss of cardiac output secondary to this and the loss of the thoracic pump secondary to positive pressure ventilation are always anticipated and very easily managed with appropriate preparation and judicious use of fluid loading to avoid them becoming problematic. If you are siginificantly concerned about the patient's blood pressure and don't want to preload with crystalloids, then the sensible option is to use fentanyl and ketamine along with suxamethonium (or a short acting NDNMBA like rocuronium or atracurium)

To be honest I haven't heard of anyone attempting intubation with sedation alone for a long time. I'm aware of a few services that still have it on hte books for respiratory collapse with the rationale being that the patient would not be able to adequately de-nitrogenated prior to intubation being attempted and thus sedation alone would allow continual respirations. However to use sedation alone, especially with a single agent, on patients with a neurological problem is scary and barbaric.

I believe that the potency of morphine is a concern. I have heard that Fentanyl is substantially more potent than morphine as much as 10 times as potent. I may have to comparatively administer a substantial amount of morphine to achieve the same effect. Because morphine introduces a vasodilatory component and is irreversible and coupled with this increased dosage I don't feel morphine is a wise choice here.

I agree Midazolam does have an indirect effect on blood pressure through its effect on muscle tone however its effect on blood pressure as compared with morphine I think is more subtle and certainly more short lived especially when you get into the higher doses of morphine.

I am at odds with the hospital about giving us Fentanyl and I don't know why they resist I'm also trying to get rocuronium added to the truck as took vecuronium off the truck in favor of etomidate, but we have to work with the tools we are given.

Sux does not sedate patients, a patient with sux alone is actually awake alert and oriented able to fully feel pain, see the practitioners around them (if their eyelids are open), hear what they are saying and smell their bad breath. What they cannot do is move, breath or respond to you, but they will remember everything that has gone on.

Proper sedation is the critical component to intubation or RSI. A pt can be properly sedated with slow and shallow respiration and be non traumatically intubated very easily and wake later with no recollection of the entire event. Yes, I advocate this and one reason among many is that any breath beats no breath.

Sux is a necessary drug to have on hand, however, in can have grave unwanted pharmacological side effects and in paralyzing the whole body it relaxes the Jaw and cardiac sphincter which is the only gate between you and a mouth full of bad. Intubation with proper sedation is not barbaric its merciful.

See my above post for the reason behind fentanyl being used. It depends on the patient as to whether you use fentanyl/midazolam, fentanyl/ketamine or fentanyl/etomidate.

Atropine is a good drug to have drawn up ready to go whenever suxamethonium is used in RSI. Suxamethonium (succinylcholine) is structurly similar to acetylcholine, so it is not unsual to see bradycardia following it's administration, which obviously affects the hemodynamics. It's not something that happens every time, but it is nice to be prepared for it. It used to be recommended that any pediatric patient recieving sux should get 20mcg/kg, under the assumption that you would notice a more profound effect from sux than in adults, but this has proven to not be necessary.

I have to ask: if you are carrying out drug assisted intubations, why on earth was this sort of thing not covered in your education?

Well aware of the similarity of sux to acetylcholine and we do keep atropine on hand. But there was no mention of using sux in my post and no mention of a bradycardia.

[Paramagic]

I believe that the potency of morphine is a concern. I have heard that Fentanyl is substantially more potent than morphine as much as 10 times as potent. I may have to comparatively administer a substantial amount of morphine to achieve the same effect. Because morphine introduces a vasodilatory component and is irreversible and coupled with this increased dosage I don't feel morphine is a wise choice here.

Naloxone reverses hyoptension associated with opioid administration as it is largely centrally mediated (although we still are concerned about the potential [and it is only potential] histamine release): Cohen RA, Coffman JD. 1980. Naloxone reversal of morphine induced perihperal vasodilation. Clinical Pharmacological Therapy Oct;28(4):541-

I agree Midazolam does have an indirect effect on blood pressure through its effect on muscle tone however its effect on blood pressure as compared with morphine I think is more subtle and certainly more short lived especially when you get into the higher doses of morphine.

Midazolam has a direct effect on vascular tone through it's effect on inflammatory mediators. The effect can also be profound, much more so than morphine.

Sux does not sedate patients, a patient with sux alone is actually awake alert and oriented able to fully feel pain, see the practitioners around them (if their eyelids are open), hear what they are saying and smell their bad breath. What they cannot do is move, breath or respond to you, but they will remember everything that has gone on.

Proper sedation is the critical component to intubation or RSI. A pt can be properly sedated with slow and shallow respiration and be non traumatically intubated very easily and wake later with no recollection of the entire event. Yes, I advocate this and one reason among many is that any breath beats no breath.

Sux is a necessary drug to have on hand, however, in can have grave unwanted pharmacological side effects and in paralyzing the whole body it relaxes the Jaw and cardiac sphincter which is the only gate between you and a mouth full of bad. Intubation with proper sedation is not barbaric its merciful.

Nobody is advocating carrying out RSI without sedation. Sedation is indeed a critical part of the process, hence everyone discussing the pros and cons of various combinations. However, intubating with sedation alone is significantly less than ideal. The whole point of sux is to eliminate jaw tone and airway reflexes, giving you the best opportunity to pass the ETT on the first attempt. Yes it relaxes the cardiac sphincter, which is why you have someone apply Sellicks maneuver when giving it. Problem solved. I didn't do many RSI's this year, only 50-60, but I certainly didn't have any problem with regurgitation in any of them.

However, to intubate with sedation alone you need very large doses of drugs to eliminate jaw tone and airway relfexes, doses that are then much more likely to cause significant side effects. You are also doing nothing to eliminate the reflexes from messing around in the most innervated structure in the body with a cold steel blade and piece of plastic. In the head injured patient all this is going to achieve is a massive and prolonged increase in ICP, to the eventual detriment of the patient.

Whether the patient is breathing or not is largely irrelevant as you de-nitrogenate the patient before attempting intubation, thus allowing ample time of safe apnea to safely pass the ETT before the suxamethonium wears off.

There is a good reason why you don't see intubation attempts on patients with sedation alone, as ERDoc's story demonstrates.

[chbare]

Just a side note: Has anybody really looked at the evidence regarding cricoid pressure?

Take care,

chbare.

[Paramagic]

Just a side note: Has anybody really looked at the evidence regarding cricoid pressure?

Take care,

chbare.

Yes, the evidence is scarce, but lack of evidence is not necessarily evidence of lacking.

[tcripp]

Sorry if I took your post to a different place. Hope this helps!

It did, but that is okay. I am learning more about the drug.

But, maybe we can get back on track? The original posted question is uses other than for RSI.

[ambodriver]

We use it with versed for drug assisted intubation....they work well together, good enough for us. However one time it did not relax a head injury pt. His jaw would not relax.

Overall I find it a useful tool.