[Businessman]

I'm a CRNA wannabe, and I have to write a paper for my Pharmacology class, where I have to talk about a specific class of anesthetics.
I chose the cardiothoracic ones, but I can't find a book or an article that discusses specifically the CT anesthetics and their uses in different situations.

Any ideas, anyone?

Thanks a lot

[lsucrna04]

Kaplan has a book we used in our program called Thoracic Anesthesia. You could also check out our student site's links
http://lasna.org

Good luck!

[versatile_kat]

I'm impressed with your website, lsucrna ... I especially liked all of the links it had available. Thanks for sharing!

[CRNA, DNSc]

I think you may approaching your paper from the wrong angle. Anesthetics are not divided into classes by the type of cases they are used in. Class of anesthetic may be more rightly considered as Local Anesthetic, Volitile anesthetic, etc. Even anesthesia has components- amnesia, analgesia, and muscle relaxation and the medications or agents we use produce varying degrees of those components. You may wish to consider such classes as sedative/hypnotics (Versed, Valium, Propofol), dissassociative anesthetics (Ketamine), Volitile agents (Isoflurane, Sevoflurane, Desflurane), non volitile agent (Nitrous Oxide), Muscle Relaxants (Zemuron, Nibex, Pavulon etc). One of these classes will make a much more manageable category for your paper.

[crna29]

In addition to CRNA DNSc's reply CT anesthesia is based upon the patients stability at the time of induction. Is there a need to preserve forward flow in a patient with valvular disease? Does the patient have a very poor ejection fraction? These are the types of things that determine what anesthetics a CT patient receives. You might look at it from the angle of which types of anesthetics preserve cardiac function the most versus those that cause severe hypotension or things of that nature. Good luck.

[Businessman]

Let me give you a little background: I already wrote the part about general anesthesia with the three stages and the most used anesthetics for those stages: induction, maintenance and recovery. You all have good suggestions, but I need two, three paragraphs showing the most used anesthetics for CT interventions, even if they are also used in other interventions as well.

[loisane]

To follow up what CRNA, DNSc and crna29 have said, but in light that you have already written some of the paper-------let me see if this helps any.

Anesthesia for open heart surgery in the past, was often done primarily with high dose narcotics. This technique is very cardiovascular stable-meaning it does not depress the myocardium in its pumping ability.

The down side, is all those narcotics take time to wear off, and patients were ventilated for days. This resulted in more effort to individualize the anesthetic. A patient with a strong heart, and preserved LV function does not need a high dose narcotic technique. This patient might have an anesthetic not too different from that for any other surgery, including the use of inhalation agents (which are known for their cardiovascular depression).

On the other hand, if there is already myocardial damage, too much inhalation agent can be detrimental, by further weakening an already weakened pump.

(This may be more than you wanted to know, but these are not simple questions to discuss). So, one angle you might try is the inhalation agent vs. narcotic decision.

Another angle could be based on the fact that the only thing that makes a cardiac anesthetic different from that for any other surgery, is the use of the cardiac pulmonary bypass pump. (Which is part of the reason you couldn't find anything by looking up "cardiac anesthetic agents"). You could talk about the pump, but there are really only a few pharmacology issues. Doses are diluted out by the increased volume of the pump, need to (or not) redose when you begin to warm the patient (accompanied by an increase in metabolism). The need for heparinazation, and its reversal at the end of surgery. A big issue in cardiac anesthesia is supporting the patient as they come off pump, but the drugs in question then are not "anesthetic" in nature. For that we are talking about volume replacement, transfusion, inotropes, vasodilators/constrictors.

Hope this has helped a bit. Difficult subject to narrow down adequately.

loisane crna

[CRNA, DNSc]

[quote=loisane]

Another angle could be based on the fact that the only thing that makes a cardiac anesthetic different from that for any other surgery, is the use of the cardiac pulmonary bypass pump. (Which is part of the reason you couldn't find anything by looking up "cardiac anesthetic agents").


Even this is not a clear angle any more- since more and more cardiac procedures are being done "off pump" or without stopping the heart and using CPB!

[crna29]

Our current "cocktail" for open heart induction includes Versed (5-10 mg), Fentanyl (20cc) and Pavulon (10mg) all up front on induction. We then maintain anesthesia using Isoforane both on and off CPB. Just prior to cannulation we give another small dose of Pavulon (4mg) and upon rewarming we often give another 5 mg of Versed. As we are leaving the OR we start a Propofol gtt at 25-50 mcg/kg/min to maintain sedation in the ICU until weaning can be begun. This "cocktail" varies for patient size (extremes in either direction) or with a sicker heart where we might add a little Etomidate. In line, during induction, we do have a syringe of Neosynephrine that is 100mcg/cc for treatment of hypotension as well as fluid rescucitation. We do try to do a slow induction to preserve the current function of the heart. Hope this helps.

[NCgirl]

Try the Manuel of Cardiac Anesthesia, by Stephen Thomas.....it's a required text in my program, and I've found I really like it. There's a chapter specific for pharm, and they speak to how all the different drugs really affect the cardiac system.