Background:Placement of a Blalock-Taussig (BT) shunt is frequently performed for palliation of cyanotic congenital heart disease (CCHD).
Objectives:Inhalational anesthetics, when used in adult heart surgery, offer advantages of myocardial protection and decrease in use of inotropes, duration of ventilation, ICU and hospital length of stay (LOS).There is little literature, however, in the comparative use of inhalational and narcotic anesthesia in CCHD.
Patients and Methods:Following Institutional Ethical Review Board approval and parental consent, 35 patients presenting for BT shunt were prospectively randomized to receive either a desflurane anesthetic or a narcotic anesthetic. Institutional practice for all patients undergoing BT shunt is to undergo cardiopulmonary bypass (CPB) following median sternotomy. Induction was accomplished with 5-7% sevoflurane in 100% oxygen, 2ug/kg fentanyl, 0.05mg/kg midazolam and 0.1mg/kg vecuronium. After intubation, patients in the narcotic group (n=16) received an additional 5-10ug/kg fentanyl, 0.1mg/kg midazolam, 100% oxygen and vecuronium. Patients in the inhalational group (n=19) received desflurane, 0.6-1 MAC, 100% oxygen, 0.05mg/kg midazolam, IV paracetamol 15mg/kg and vecuronium. At the end of surgery, patients were transferred to the ICU and received IV paracetamol and midazolam. Ventilation was weaned when the patient was hemodynamically stable. Demographics, baseline, intra and post-op heart rates, duration of inotrope use, ICU and hospital LOS, pre and post-op creatinine and serious adverse events (SAE) were recorded. Data were analyzed using Student, paired t, Mann-Whitney U and Chi square/Fisher exact tests, P < 0.05 significant.
Results:Demographic data were similar, except for a modestly higher pre-op heart rate in the group receiving opioid anesthesia. Patients receiving desflurane had a significantly shorter duration of mechanical ventilation and length of ICU and hospital stay. Inotrope use was similar in both groups. The group receiving opioid anesthesia had an increase in creatinine post operatively which was not observed in the desflurane group. There was no difference in incidence of significant adverse events in either group.
Conclusions:Use of inhalational anesthesia has increased in adult cardiac surgery and has proved to reduce duration of elective ventilation, decrease ICU and hospital LOS, and mortality. Inhalational anesthetics are less well-studied in CCHD. In the current study, desflurane was chosen because of its low solubility, decreased recovery time and lack of metabolism or organ system toxicities. Although it is a popular belief that desflurane is associated with tachycardia and airway irritation, findings of the current study are consistent with those of the previous works demonstrating a lack of these side effects below 1 MAC3. No hemodynamic instability was encountered and there was no evidence that desflurane exerted a negative inotropic effect. Markers of cardio protection were not examined, although desflurane may have had a renal protective effect compared to narcotic technique. In the current study, a desflurane anesthetic for BT shunt decreased the duration of mechanical ventilation and ICU and hospital LOS by nearly three days, with no difference in perioperative morbidity or mortality. Larger studies are required to determine whether these changes result in overall decreased complication rate and morbidity/mortality and whether desflurane has a cardio or renal protective effect in the patient population.
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