Beyond the Red Lines
Dr. Mark Nelson, and Harry “Mac” McCarthy, certified clinical perfusionist, work in an area carefully protected for their surgical patients and separate from the rest of the hospital. The surgical suite located in the VCU Medical Center’s Critical Care Hospital has its own elevator that requires special access.
Upon arrival to the floor, visitors are asked to wear sterile coverings—a white “bunny suit,” along with slippers and a cap. Once they are zipped up and ready, they can step over the red lines that designate the surgical areas. It is here that Nelson and McCarthy direct the cardiac anesthesia and perfusion teams.
Normally the fifth floor lunchroom is quiet, but today a large group of co-workers are gathered to celebrate someone’s last day. Pauley’s chief of cardiothoracic anesthesiology Dr. Mark Nelson, is sitting at a nearby table. Dressed in blue scrubs, Nelson is friendly and patient. Although the room grows a little noisy, he smiles, appreciating the camaraderie. Amid the busyness of the room, he stays focused
on the interview questions. When he talks, he sometimes pauses to find the exact,
precise word.
Precision and focus are integral parts of Nelson’s job. He and his seven-member team carefully measure and control the anesthesia that they give to 800 cardiac patients each year. Some have rhythm problems or blockages, others have structural defects or advanced heart failure. Almost all require general anesthesia.
Working in a tertiary medical center, he sees many high-risk patients. “Our surgeries often involve complex procedures, including partial and total artificial hearts and other forms of artificial circulation, to stabilize the patient,” he said. “The margin of error in care provided is narrow as the patients are already severely compromised by their cardiac disease at the time of surgery.”
Nelson’s work begins with a review of the patient’s medical records and surgical plan. Sometimes allergies are noted in the history. Reactions are rare, he says, but when they happen, they can be controlled with other medications. Nelson enjoys meeting the patients and calming any anxiety they may have.
“Dr. Mark Nelson has brought a world-class level of expertise, clinical experience, knowledge and rigor to cardiac anesthesia. He is an immensely talented individual who is a master at working with different teams of cardiology professionals. He has given VCU Health a top-tier cardiac anesthesia team.” — Dr. Kenneth Ellenbogen
“Probably the most common question we encounter as cardiac anesthesiologists is, `Are you going to put me to sleep?’ Well, the cardiac anesthesiologist is going to do that, but much, much more.”
During surgeries, Nelson carefully monitors the patient’s respiratory and cardiac status, tweaking the dose or adding supplemental medications if problems arise.
“Anesthesia, in general, depresses cardiac function, and so these patients require additional efforts by the anesthesiologist to create good outcomes,” he says.
Nelson also makes expert evaluation of the heart both before and after the repair procedure, using transesophageal echocardiography. This involves inserting an ultrasound transducer endoscopically—that is, via a long, thin tube—through the esophagus.
“It was anesthesiologists who pioneered this technique in the 1980s, which is now the standard of care for many cardiac procedures,” he said. All faculty members in his division have advanced certification in this area.
Patients sometimes require blood and/or blood component transfusions. In addition to the anticoagulation necessary for cardiopulmonary bypass, the obligatory inflammatory response can result in substantial bleeding post-op.
“These blood issues are managed with advanced methods of assessing clotting status and administration of clotting factors following cardiopulmonary bypass. The heart is often stunned or sluggish and will require additional medications to restart appropriately,” he explains. “This is often very challenging.”
Though the job is intense, he wouldn’t have it any other way. “Being a team member in this endeavor is very rewarding, and seeing the patient complete the operation, leave the ICU, and ultimately leave the hospital with a repaired, mechanical or new heart is an extraordinary experience.”
“Heart surgery would not be possible without the help of Dr. Nelson and his team,” said Dr. Anthony Cassano, chair of the Division of Cardiothoracic Surgery. “They are an integral part of every cardiac operation, and by far, some of the best physicians in the health system. I would let any one of them care for me or my family.”
“Your blood perfuses your tissues and your organs, so your blood right now is perfusing your brain, your kidneys, your heart and lungs,” he says. “When your heart is stopped, you need something to take over the perfusion.”
He explains that when a patient requires cardioplegia—a solution given to cause the intentional stopping of the heart for surgery, using a high-potassium solution—a cardiopulmonary bypass machine fills that need. The machine draws the patient’s blood out of a body to a reservoir, then to a pump, then into an oxygenator, where oxygen is added into the blood and carbon dioxide is removed. Then it’s returned to the patient.
He says the blood leaves the body by special tubing—known as a cannula—that connects to the right atrium; the blood returns to the body by a cannula that connects to the aorta. The direct connections allow the blood circulation to bypass the heart, creating as bloodless a surgical field as possible.
“The surgeon can then operate on a relatively motionless heart and can open the chambers of the heart to repair the structures within,” he says.
McCarthy points out a rolling console with a canister, which stores blood collected during and after surgery in cases where a lot of blood loss is anticipated. The collected blood is rinsed and filtered prior to being reinfused back into the patient. He also operates various cardiac assist devices that the patient may require during surgery.
“What we do, in essence, is operate a number of pieces of mechanical equipment to approximate what the patient’s heart does to continue the circulation while the heart is stopped.”
“Harry McCarthy – `Mac’ as he is known to the team—is the Man. When I joined the program 17 years ago, I knew this was going to be a great program with the outstanding perfusion group led by Mac. With his help, we went to modern blood conservation, novel methods of cardioplegia, switching to vacuum assist, expanded the extracorporeal membrane oxygenation program, developed the total heart program and many other innovations…
The perfusion team is the key to cardiac surgery.” —Dr. Vigneshwar Kasirajan
In addition to tending to surgical patients, McCarthy also operates extracorporeal membrane oxygenation (ECMO) pumps for those who need life support because their heart and lungs are not able to sustain them. The work brings him to the bedsides of patients across the state, who are brought to VCU by a special helicopter or MOBI, a mobile intensive care transportation rig.
VCU Health has six heart-lung bypass machines. About 80-90% of the cases are scheduled, while 10-20% are emergencies. Ten perfusionists handle the 800 adult and pediatric cases each year, of which 420 involve cardiopulmonary bypass. They also help with an additional 60-90 ECMO cases each year.
A perfusionist since 1979, McCarthy has seen a variety of changes, including improvement of safety features, miniaturization and more computerization. Additionally, “innovations in the cath lab have reduced the number of patients who come to the operating room with coronary artery blockages. So, the patients that we get tend to be sicker than those from previous years and have more coexisting problems.”
He saw his first transplant in the early 1980s; even today, “there’s always a feeling of accomplishment when the new heart starts to beat.”
“You can’t say enough about Mac, as well as the entire perfusion team. They are always enthusiastically accommodating in their role with respect to providing support for the cardiac surgery team. Also, they are extremely involved and supportive in the growth of our in-house, as well as our Mobile ECMO and other outreach programs,” said Dr. Patricia Nicolato, director of the adult ECMO program.
TOP: (L TO R): DR. AARON LIM, DR. JEFFREY GREEN, DR. MARK NELSON, DR. NIRVIK PAL, AND DR. PRANAV SHAH
BOTTOM: (L TO R): CCP TEAM MEMBERS GEOFF HALL, ADAM BLAKEY, HOLLY WILSON-LETTS, MAC MCCARTHY, AND LISA ALTOMONTE
