Overcoming Challenges in the Management of Critical Events During Cardiopulmonary Bypass.

Critical events during cardiopulmonary bypass (CPB) can challenge the most experienced perfusionists, anesthesiologists, and surgeons and can potentially lead to devastating outcomes. Much of the challenge of troubleshooting these events requires a key understanding of these situations and a well-defined strategy for early recognition and treatment. Adverse situations may be anticipated prior to going on CPB. Atherosclerosis is pervasive, and a high plaque burden may have implications in surgical technique modification and planning of CPB. Hematologic abnormalities such as cold agglutinins, antithrombin III deficiency, and hemoglobin S have been discussed with emphasis on managing complications arising from their altered pathophysiology. Jehovah's witness patients require appropriate techniques for cell salvage to minimize blood loss. During initiation of CPB, devastating situations leading to acute hypoperfusion and multiorgan failure may be encountered in patients undergoing surgery for aortic dissection. Massive air emboli during CPB, though rare, necessitate an urgent diagnosis to detect the source and prompt management to contain catastrophic outcomes. Gaseous microemboli remain ubiquitous and continue to be a major concern for neurocognitive impairment despite our best efforts to improve techniques and refine the CPB circuit. During maintenance of CPB, adverse events reflect inability to provide optimal perfusion and can be ascribed to CPB machine malfunction or physiological aberrations. We also discuss critical events that can occur during perfusion and the need to monitor for organ perfusion in altered physiologic states emanating from hemodilution, hypothermia, and acid-base alterations.

Intraoperative transesophageal echocardiography to evaluate acute cessation of venous inflow during cardiopulmonary bypass.

Acute disruption of venous return during cardiopulmonary bypass (CPB) may be due to malposition of the venous cannula, kinks or obstruction of the venous tubing by a smaller cannula, airlock, or mechanical disruption of blood flow. We describe an acute obstruction of the venous cannula by blood clots that were visualized on the transesophageal echocardiogram during CPB. Appropriate measures were taken by the surgeon to evacuate the clot and restore CPB. The clots were not seen on the transesophageal echocardiogram before CPB raising suspicion that they originated in a lower extremity and migrated to the right atrium resulting in venous cannula obstruction.

Acute and chronic respiratory failure.

Respiratory failure (RF) can be attributed to a plethora of neuromuscular diseases (NMDs) and manifests clinically in a multitude of overt or more subtle ways. The basic principles of pathophysiology, diagnosis and treatment of neurologic diseases and of RF apply concomitantly to this subset of patients. Various entities should be approached according to the latest evidence-based recommendations. Treatment follows the natural disease progression, from minimal respiratory assistance to mechanical ventilation (MV). A comprehensive treatment plan has to be formulated that takes into consideration the patient's wishes.