Can The Use of Powerful Drugs Be Reduced During Heart Surgery?

In most open-heart surgeries, heart medication has proved to be a critical factor in its success

While the medical fraternity still recommends medication like statins and blood thinners to be used after open-heart surgery or CABG to prevent future complications and survival, the research on how to reduce the use of powerful drugs during such surgery continues. 

In this article, we will discuss whether the use of powerful drugs can be reduced during heart surgery.

According to some research, monitoring the brain functioning with Masimo SedLine can help reduce the use of opioids and anesthetic agents during cardiac surgery. 

When Does One Need Heart Surgery?

One of the most common heart surgeries is the CABG, in which a healthy one is grafted on the blocked artery or vein. There are several instances when an individual can need an open heart surgery: 

• Repairing or replacing the heart valves to allow unhindered blood flow through the heart
• Repairing abnormal or damaged areas of the heart 
• Help the heart to beat properly by implanting a medical device
• Heart transplant where a damaged heart is replaced with a healthy heart 

How Is Open Heart Surgery Performed?

Typically the procedure takes between three and six hours where the following steps are performed:

• A patient is given anesthesia to ensure the surgery is pain-free and the patient is asleep 
• The surgeon does a cut of 8 to 10 inches 
• The breastbone and all the other parts are cut so that the heart can be exposed
• The heart is then connected to a heart-lung bypass machine. It helps remove the blood from the heart for the surgeon to operate. However, new devices are now being used, making the heart-lung bypass machine obsolete. 
• Once the procedure on the heart is complete by the surgeon, the breast bone is closed with a wire. 
• The original cut is then stitched up 

All along this process and later on, powerful drugs are administered to the patient. But now, researchers are being done to replace these drugs that can cause more damage than cure in the patient's life. 

How Can The Use Of Powerful Drugs Be Reduced During Heart Surgery? 

In the Journal of Cardiothoracic and Vascular Anesthesia, a study was published which was conducted by the researchers of Montreal Heart Institute on how to reduce the use of drugs in heart surgery. In the study, it was inferred that the use of anesthesia guided by electroencephalography (pEEG) could help reduce the use of inotropic and vasoactive drugs. It can also help lessen the opioids and anesthetic agents in the OR. 

The pEEG -guided anesthesia can further lower the central venous pressure (CVP), lessen the intraoperative bleeding, cause lesser fluid administration, and shorten the duration of the patient on the mechanical ventilation. 

The study further revealed that the anesthesia guided with pEEG helps reduce the instability of the hemodynamics during the separation of cardiopulmonary bypass (CPB).

Researchers conducted the study by stratifying the operation and measuring it into three categories, easy, difficult, and complex. The easy category used only one inotropic or a single vasoactive drug. The difficult category used a minimum of two different classes of drugs, and the complex section required the use of mechanical circulatory support or returning to CPB. 

They observed the other goal of reducing drug use during heart surgery by evaluating how and whether the pEEG-guided anesthesia would allow the operative procedure to the hypothesized reduction of the inotropic and vasoactive drugs used in the ICU. This was done by measuring the vasoactive and inotropic scores (IVS). 

What Did The Study Reveal? 

The study used a retrospective method to determine the result. It used a cohort of 300 adult patients. They used them between 2013 and 2020 CPB for the cardiac surgery they underwent at the Montreal Heart Institute. These patients were then divided into two groups based on whether they had pEEG-guided anesthesia or not. It is worth noting that pEEG-guided anesthesia became standard practice at Montreal Heart Institute in 2017. 

The patients who were part of the pEEG anesthesia group had been under monitoring. Their brain functions were monitored and recorded using Masimo's SedLine from the time they went into the ER to their arrival in the ICU. This group of patients also received a lower rate of vasoactive and inotropic drugs during the first hour after arriving in ICU. It hence resulted in lower IVS scores. 

Furthermore, the group with pEEG-guided anesthesia reduced the chance of being in the VIS category by 57 percent. Also, the result indicated they had lower duration in the intraoperative fluid balance and mechanical ventilation and reduced bleeding amount. 

Although a particular portion, though a small number, experienced CPB separation to be unsuccessful. The researchers adjusted other parameters for which they used several logistic to identify the regression. It noted that during this process, the reason for the unsuccessful separation of CPB was not due to the pEEG-guided anesthesia. Instead, the cause of the issue was linked to several other independent factors that were known predictors of complications for hemodynamics.  

Why Should The Use Of Drugs Be Reduced?

Researchers have been able to link renal dysfunction and mortality with the use of high postoperative doses. In most cases, they are inotropic and vasoactive drugs. As a result, the study of using pEEG-guided anesthesia was used to determine whether it can improve the stability of hemodynamics while decreasing the use of these drugs during cardiac surgery and in the postoperative scenario in the ICU. 

Since most heart surgeries have the risk of excess bleeding and damage to the liver, kidney, lungs, and other tissues due to the medication, infection, drug allergies, and reaction to anesthesia, the possibility of using a less potent drug during and after the surgery can prove to be beneficial. Mainly for those with pre-existing diseases like diabetes, kidney, lung, or other peripheral artery diseases. 

Even in the case of minimally invasive heart surgery, the risks of bleeding, infection, and arrhythmia due to drugs can occur. Therefore, more research is being done to identify how the use of powerful drugs can be reduced during and after heart surgeries.