Reason of hypernention in Post CABG OP

Post CABG pts need to have their MAPs (mean arterial pressures) to stay within a certain range to prevent excessive bleeding or blowing the grafts. Emergence from anesthesia and increasing agitation can cause the MAPs to go up, as well as, hypoxia, hypercarbia, and hypothermia with shivering.

First, it's spelled hypertension.

Nitro-- for coronary artery dilation, and prevent post op occlusion/spasm.

Nipride-- primary vasodilation, treats post-op hypertension, due to hypothermia from CPB and release of catecholamines upon awakening. This also prevents spasm, post op MI, and htn.

I don't want to start anything here, but I think the last poster was rude. It was obviously just a typo, let it go.

Most patients have problems with HYPOtension immediately post-op. At least in my experience. Most people with pre-op hypertension may be hypertensive post-op. Rewarming post-op will usually cause hypotension due to vasodilation.

As you awaken from surgery post-operatively, your vessels do not clamp down as much, and you experience vasodilation, created by re-warming. Because you are opening up your blood vessels with re-warming, you are opening up the flood gates so to speak, thus increased oxygen consumption, metabolism, temperature, and heart rate. The patient may experience shivering, and a realease of catecholamines due to stress, thus the increase in blood pressure with re-warming. Typically once all this has settled out, one may experience hypotension, but with re-warming post-operatively, you experience hypertension, not hypotension. Other factors cause hypotension post-operatively, and this might necessitate volume, blood, or the use of vasopressors. Because, hypertension occurs so often post-operatively though, Nipride is usually the drug of choice. Some facilities choose to use Nitrogylcerin I do believe. Nipride decreases the systemic vascular resistence experienced post-operatively, especially in the periphery where the resistence is higher because the body is colder. Re-warming takes place core to periphery, and as re-warming occurs, one will find the resistence getting higher if something like nipride is not used to lower it.

My experience is hypotensive problems with most post-op hearts. This may be due to differences between our institutions. Generally our patients come back pretty dry. Our hearts do not usually have shivering problems, and we rarely have to manually re-warm someone. But when we do, we get hypotension due to vasodilation. The patients who are hypertensive are usually the valves and carotids. Most of the valves were hypertensive pre-op.

I just wonder if your patients come back hypertensive because they are coolerand/or wetter than ours. If you don't have the volume to support the vasodilation, hypotension will result. Vasodilation (opening the flood gates) will decrease oxygen consumption, by decreasing pre/afterload unless you don't have the volume to support decreased SVR. I don't see increased heart rate being associated with vasodilation unless there is a volume issue. I also haven't seen increased SVR associated with rewarming (unless there is shivering or pain involved)

Post operative hypertension occurs in 30-60% of cardiac surgical patients. If a patient comes back from the operating room dry, it necessitates a lot of IVF, and generally yeah they will be hypotensive. We typically use albumin. I can give 3 albumin before calling the doctor. Our patients don't always come back dry, but more often, valves come back hypertensive because the increased gradient causes more stress on the peripheral circulation orginally protected by the aortic stenosis. Decreases in cardiac output can be caused by increased SVR, thus the need for volume, and Nipride. Pain, hypoxia, and rebound hypertension (from beta blockers) are also causes of post operative hypertension

Our patients are generally pretty cool, but not all the time. Typically they come back with a temp of 35.5 or higher, but I have seen them as low as 34.0 C. Shivering is not always do to low temp either. It is also due to the anesthesia effects wearing off, and even if this is the case, the patient will become hypertensive in response to shivering and awakening. Usually a little morphine is helpful. As you release catecholamines, and the body starts to awaken, HR goes up. You have an increased SVR especially in valve patients because 1) generally they need volume, and 2) a low body temp creates vascular resistence. Shivering does not cause increased svr. low body temp especially in the periphery will. shivering may contribute to an increased heart rate. If you have a higher SVR, you will have less vasodilation, but as rewarming occurs, blood fills the periphery, and you end up giving volume a lot, and using nipride to bring down SVR.

I don't want to start anything here, but I think the last poster was rude. It was obviously just a typo, let it go.

I totally agree!

I totally agree!

I love it when people come in 3rd hand and make comments that aren't even directed toward the discussion. At least my comments contributed to the discussion toward nipride and nitrogylcerin, or did you forget what the topic was? I simply pointed out the proper way to spell hypertension. Sheesh, it doesn't take much to offend these days, does it? So if you don't have anything worthwhile to add to the discussion about Nipride and Nitro, then go to another forum.

I was simply agreeing. You can let it go now.:kiss

Being annoying is more like it.