What was done first after the patient was in supine position?

In surgical procedures, especially those involving significant interventions like cardiac surgery, the administration of general endotracheal anesthesia is typically one of the first critical steps after the patient is positioned supine. This step is essential to ensure that the patient is deeply sedated and adequately ventilated before any invasive interventions are started.

Once the patient is properly anesthetized, the surgical team can ensure that the patient is unresponsive and relaxed, which is necessary for both safety and effective performance of the surgical procedure. Anesthesia not only alleviates pain but also provides muscle relaxation and prevents movement, which is crucial when making incisions or using surgical instruments.

After the administration of anesthesia, other steps, such as making the median sternotomy incision or cannulating the aorta, would follow, ensuring that the patient remains stable throughout the operation. Cooling the patient might occur later in the process, particularly in surgeries that require hypothermia for certain cardiac procedures. Thus, administering anesthesia first is a standard and necessary practice in surgical protocols.