EXPERT ANALYSIS AT THE STS ANNUAL MEETING
PHOENIX (FRONTLINE MEDICAL NEWS) – In the clinical opinion of Dr. Nevin M. Katz, caring for critical care patients after cardiothoracic surgery requires a multidisciplinary team.
“It used to be just the surgeons and the residents and anesthesiologists, but in this era, it’s a broad team,” Dr. Katz said at the annual meeting of the Society of Thoracic Surgeons. “Coordination of the team, which includes surgeons, anesthesiologists, physician assistants, bedside nurses, nurse practitioners, perfusionists, pharmacists, respiratory therapists, and nutritionists is very important, and it’s important that members of the team be on the same page.”
Dr. Katz, a cardiovascular surgeon/intensivist at Johns Hopkins University, Baltimore, went on to offer tips for managing right ventricular failure in cardiac surgical patients. He recommends that clinicians consider five basic parameters of hemodynamic management: the heart rate and rhythm; the preload; the afterload; contractility; and the surgical result, including the potential for an anatomic problem and the risk of cardiac tamponade. “One must also consider a cardiac assist device,” he said.
He recommended that the cardiac index goal for cardiovascular patients in the ICU be in the range of 2.2-4.4 L per min/m2. The recommended hemodynamic goals also included systemic blood pressure ranges with a systolic pressure of 90-140 mm Hg and a mean arterial pressure of 70-90 mm Hg; a left arterial pressure or pulmonary capillary wedge pressure of 5-18 mm Hg, a right arterial pressure or central venous pressure of 5-15 mm Hg, and a systemic vascular resistance of 800-1,200 dynes per sec/cm5. “When treating right ventricular failure or complex patients, I think advanced PA [pulmonary artery] catheters are valuable, although they’re not absolutely necessary,” he said.
Complementary technologies available in most ICUs can help clinicians manage these patients, particularly ultrasound. With ultrasound, “we can determine where the patient is on the ventricular function curve, regional versus global dysfunction, right ventricular versus left ventricular dysfunction, valve dysfunction, and cardiac tamponade,” said Dr. Katz, who also created the Foundation for the Advancement of Cardiothoracic Care, also known as FACTS-Care . “It’s a very important monitoring modality.”
An important goal in managing patients with right ventricular failure is to establish an optimal heart rate and rhythm. “We have modalities to treat bradycardia and heart block,” he said. “Loss of atrial contraction is very important. If we can avoid atrial fibrillation, that’s good. Ventricular arrhythmias can be a problem, and nowadays we can treat atrioventricular and ventricular dyssynchrony.”
Optimal preload requires a focus on volume responsiveness, Dr. Katz continued. “Where is the patient on that ventricular function curve?” he asked. “With the advanced PA catheters, there are ways to look at that. You would like to be on the ascending part of that curve.” Clinicians can also use pulsus paradoxus, a variation of systemic arterial pulse volume. “That will indicate that perhaps you’re low in volume, but you can use stroke volume variation with an advanced PA catheter,” he said. “If your stroke volume variation is greater than 15% you’re on the ascending part of the curve. But if your stroke volume variation is less than 15%, your volume is probably optimal and you’re not going to be volume responsive.”
Clinicians who lack the benefit of an advanced PA catheter can assess volume responsiveness with passive leg raising.
Low preload causes of RV failure include hypovolemia, bleeding, third-spacing, high urine output, and cardiac tamponade. High preload can be a problem, too, from excess fluid administration, tricuspid or pulmonary valve regurgitation, or from left to right shunting.
Overall, optimal management of RV failure depends on the coordination of the multidisciplinary critical care team.
Dr. Katz reported having no financial disclosures.