Intraoperative Procedures & Patient Monitoring Flashcards

What is the primary role of a perfusionist during cardiac surgery?

Answer: Manage extracorporeal circulation

The primary role of a perfusionist during cardiac surgery is to manage the extracorporeal circulation, specifically operating the heart-lung machine. This involves monitoring and controlling blood flow, oxygenation, temperature, and blood chemistry to support the patient's physiological functions. They ensure the patient's body is adequately perfused while the heart and lungs are bypassed.

Which parameter is most critical during cardiopulmonary bypass?

Answer: Arterial pressure

During cardiopulmonary bypass, arterial pressure is a critical parameter to monitor because it directly reflects the perfusion pressure delivered to the patient's organs and tissues. Maintaining an adequate arterial pressure ensures sufficient blood flow and oxygen delivery, which is essential for preventing organ damage and supporting overall physiological stability. Deviations can indicate serious issues.

Why is temperature control important during bypass?

Answer: Protect organs and reduce metabolic demand

Temperature control, particularly inducing hypothermia, is crucial during bypass to protect organs. Cooling the body significantly reduces the metabolic rate and oxygen demand of tissues, making them more resilient to periods of reduced blood flow and preventing ischemic damage during complex cardiac procedures. This neuroprotective strategy is vital for patient outcomes.

Which device is used to assess oxygen saturation continuously?

Answer: Pulse oximeter

A pulse oximeter is the device used to continuously assess oxygen saturation (SpO2) in a non-invasive manner. It provides real-time data on the percentage of hemoglobin carrying oxygen, allowing the perfusionist and surgical team to monitor the patient's oxygenation status throughout the procedure. This continuous feedback is essential for maintaining adequate oxygen delivery.

What does a venous saturation monitor measure?

Answer: Oxygen usage in tissues

A venous saturation monitor measures the oxygen saturation of venous blood (SvO2 or ScvO2). This value reflects the amount of oxygen remaining in the blood after it has circulated through the tissues, thus indicating how much oxygen the tissues have extracted and used. It provides crucial insight into the balance between oxygen delivery and oxygen consumption, helping assess tissue perfusion adequacy.

What is the significance of ACT testing during bypass?

Answer: Assess anticoagulation level

ACT (Activated Clotting Time) testing is vital during cardiopulmonary bypass (CPB) to measure the effectiveness of heparin, an anticoagulant. Heparin is administered to prevent blood clotting within the extracorporeal circuit, which could lead to serious complications. Monitoring ACT ensures the patient's blood is adequately anticoagulated throughout the procedure, allowing for safe management and reversal post-bypass.

How can perfusionists detect air embolism?

Answer: Using bubble detectors

Air embolism is a critical and potentially fatal complication during bypass, where air enters the patient's bloodstream. Perfusionists utilize specialized bubble detectors, often ultrasonic, placed strategically on the bypass circuit to continuously monitor for the presence of air bubbles. Early and accurate detection is paramount to prevent air from reaching vital organs like the brain, which could cause severe neurological damage or death.

What is the role of hemodilution during bypass?

Answer: Enhance microcirculation

Hemodilution, the dilution of blood with crystalloid solutions, is a common practice during cardiopulmonary bypass. This process reduces blood viscosity, which in turn significantly improves blood flow through the body's smallest vessels, known as microcirculation. Enhanced microcirculation ensures better oxygen and nutrient delivery to tissues, protecting organs from ischemia, especially during periods of reduced flow or hypothermia.

Which blood parameter is critical to monitor for tissue oxygenation?

Answer: Arterial blood gases

Arterial blood gases (ABGs) provide crucial real-time information about a patient's oxygenation, ventilation, and acid-base balance. Perfusionists meticulously monitor parameters such as PaO2 (partial pressure of oxygen), PaCO2 (partial pressure of carbon dioxide), and pH from ABG samples. This allows for precise adjustments to the bypass circuit's gas exchange and flow, ensuring optimal tissue oxygenation and metabolic stability throughout the surgical procedure.