This is likely due to the anticipated effects of anesthetic agents, the supine position, and positive pressure ventilation. Pericardial decompression is the definitive treatment; the surgeons should be informed immediately to begin without delay while resuscitative efforts continue. Preload should be maximized with fluid bolus and minimization of positive pressure ventilation using a combination of hand ventilation with low tidal volumes and limited apnea with 100% inspired oxygen. Contractility should be maintained with boluses of epinephrine and calcium if deficient, and anesthetic agents should be titrated to ensure amnesia without excessive negative inotropy. Afterload should be maintained by titrating norepinephrine to achieve a MAP of 60 to 65 mm Hg to preserve critical organ perfusion. In the event of worsening CO, cardiac massage might be required. It should be noted that external cardiac massage has reduced efficacy in cardiac tamponade due to the elevated cardiac filling pressures, which continue to impede venous return during the relaxation phase of chest compressions. In a situation where chest compressions are being considered, opening the pericardium should occur immediately instead.

References

• Carmona P, Mateo E, Casanovas I, et al. Management of cardiac tamponade after cardiac surgery. J Cardiothorac Vasc Anesth. 2012;26:302-311.
• Morozowich ST, et al. Uncommon Cardiac Diseases. In: Kaplan JA, et al., eds. Kaplan's Cardiac Anesthesia. 8th ed. Elsevier; 2023:698-759.