The reasons are three-fold. (a) Many of the drugs used for anesthesia have important cardiac side-effects. (b) Surgery is a stressful situation. Surgical stress may make the existing heart disease turn worse. (c) Cardiac diseases may flare up suddenly, and unexpectedly without any obvious cause.
A well-taken history, physical examination, and laboratory investigations are the corner-stone for risk assessment.
Goldman and associates’ Cardiac Risk Index Score (CRIS) is used to make an accurate assessment of the Patients’ surgical risks. The chance of an adverse cardiac outcome is dependent on the presence of one or more pre-existing diseases such as heart failure, myocardial ischemia, atherosclerotic cerebral vascular disease, diabetes mellitus, chronic renal failure, as well as the nature of the surgical operation.
This is a difficult situation because surgical operations cause excess of bleeding in subjects who are on DAPT. On the other hand, stopping the DAPT may result in stent thrombosis. Furthermore, there may me a necessity of emergency surgery.
For elective non-cardiac surgery, we give a gap of 4 weeks after bare metal stent implantation, and at least one year after drug eluting stents.
If the surgical operation is so urgently required that we cannot wait until one year has elapsed, we stop clopidogrel/prasugrel /ticagrelor, ang continue to give aspirin. There must be a few days’ gap between the stoppage of these drugs and the surgical operation, which is as follows: clopidogrel 5-7 days, prasugrel 7-9 days, and ticagrelor 5 days. DAPT should be promptly resumed following surgery. Interruption of DAPT even for a few days before or after surgery may result in a fresh heart attack.
No, it is wrong to assume that the inhalation of gas for anesthesia is harmful and that injections are safe. In fact, both have their advantages and disadvantages. Cardiologists should never tell their anesthesiologist colleagues as to what they should use for the purpose of anesthesia. In fact, anesthesiologists are competent people and know what to do.
We try to maintain the following parameters within the acceptable range: pulse rate, blood pressure, temperature, blood oxygen and carbon dioxide, fluid intake and output, and ECG monitoring. A few critical patients need to have additional monitoring devices.
In addition, we administer small doses of permitted pain-killers and sedatives in order to keep the patients comfortable, and avoid letting them become agitated.
It is gratifying to recollect that most cardiac patients are up on their feet within a couple of days, and go back home in less than a week.
This article is published for the purpose of creating awareness regarding heart disease amongst members of the public, and is not intended to be a substitute for expert medical opinion. Therefore, for all health-related issues, please consult your healthcare giver.