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A 25-year-old man with hypoplastic left heart syndrome who had a Fontan procedure 20 years ago presents for laparoscopic appendectomy. He complains of right lower quadrant pain for 2 days with nausea and vomiting, which has now resolved. He has had decreased oral intake because of the pain. An IV was started, and he was given 1 L of lactated Ringer’s in the emergency room. He was also started on ampicillin/sulbactam and morphine in the emergency room.
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Physical examination: 85-kg male, well developed.
Echocardiogram: Qualitatively good ventricular function, no intra-atrial shunting, patent Fontan pathways, trivial triscuspid regurgitation.
Labs: White blood count 18; hematocrit 41.
Ultrasound: Inflamed appendix.
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PREOPERATIVE CONSIDERATIONS
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Advancements in the medical and surgical management of complex congenital cardiac diseases requiring staged single ventricle procedures and ultimately palliated to Fontan physiology have improved survival into adulthood. More of these patients are now presenting for noncardiac surgery and pose a challenge to anesthesiologists who are not used to taking care of patients with congenital cardiac disease.
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The first successful Fontan procedure was published by Norwood in 1983, and these patients have now reached adulthood. In Fontan physiology, systemic venous blood passively flows directly into the pulmonary circulation to be oxygenated and returns to a common atrium and single ventricle in the heart to perfuse the systemic circulation. The primary driving force promoting pulmonary blood flow and eventually cardiac output is the transpulmonary gradient, which is the difference between central venous pressure and systemic ventricular end-diastolic pressure. Factors that affect blood flow include systemic venous pressure and volume, pulmonary vascular resistance, cardiac rhythm, and ventricular function. Any perturbations in these factors can compromise blood flow and cardiac output.
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It is necessary to inquire about feeding status, any episodes of vomiting and diarrhea, and decreased appetite to assess fluid status because there can be severe hypotension upon induction of anesthesia. It is important to maintain normovolemia prior to any anesthetic induction. Obtain an electrocardiogram and an echocardiogram to assess for ventricular function, intracardiac shunting, patency of the Fontan circuit, and valvular function. Prior catheterization reports may provide additional information about pressures in the Fontan circulation.
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ANESTHETIC MANAGEMENT
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Give an intravenous fluid bolus prior to induction. This is even more important in patients who are to undergo laparoscopic procedures because insufflation of the abdomen will further decrease venous return and cardiac output.
Place intermittent pneumatic compression device on legs prior to induction because blood flow is sluggish, so these patients are at risk for thromboembolic events.
Avoid drugs that can cause myocardial depression or reduce ventricular function.
Consider using midazolam, fentanyl, etomidate and rocuronium for induction of anesthesia.
Consider maintenance with a narcotic-based anesthetic such as remifentanil infusion to maintain cardiac stability and to decrease minimum alveolar concentration requirements of anesthetic gas.
Ask surgeons to keep insufflation pressures ...