How to cite this article: Parida S, Mohan R M, Bhat RR, Mishra SK, Badhe AS. Anesthesia for noncardiac surgery in infant with undiagnosed single ventricle. Ann Card Anaesth 2010;13:266-7
How to cite this URL: Parida S, Mohan R M, Bhat RR, Mishra SK, Badhe AS. Anesthesia for noncardiac surgery in infant with undiagnosed single ventricle. Ann Card Anaesth [serial online] 2010 [cited 2022 May 21];13:266-7. Available from: https://www.annals.in/text.asp?2010/13/3/266/69068
A 9-month-old infant was admitted to the pediatric surgical unit for repair of an occipital meningoencephalocele. History was unremarkable other than the problem that he presented with. Examination revealed a healthy infant with no evident pallor, cyanosis, clubbing, lymphadenopathy, icterus or respiratory tract infection. Chest was clear to auscultation and there were no apparent murmurs. Hemoglobin concentration (Hb%) was 14.8 g/dl. Congenital lesions of the central nervous system are generally not associated with other anomalies or congenital heart diseases (CHD).  Therefore, routine preoperative work-up did not include cardiologic evaluation. Anesthesia was induced with sevoflurane in oxygen. Pulse oximetry showed an SpO 2 of 91%. Post-intubation, SpO 2 remained at 96% even with an FiO 2 of 1.0. Endotracheal tube position was proper, airway pressures were normal and bilateral vesicular breath sounds auscultated with no adventitious sounds. Possibility of some CHD missed at preoperative evaluation was then considered. Since there was no obvious cyanosis, we ascribed the desaturation to right-to-left intracardiac shunting or a mixing lesion. So, we decided to try and preserve the ratio of pulmonary to systemic vascular flows by manipulating the hemodynamics with sevoflurane adjusted to maintain a blood pressure of 20% pre-induction value. Respiratory rate was adjusted to maintain end tidal carbon dioxide around 33-34 mm Hg. With these ventilatory adjustments and an FiO 2 of 0.4, oxygen saturation ranged between 91 and 93%. Post-extubation arterial blood gas ABG revealed the partial pressure of oxygen of 53 mm Hg, and that of carbon dioxide of 44 mm Hg and no metabolic acidosis. The child was transferred to the pediatric surgery ward while oxygen was administered via an oxygen hood the infant had SpO 2 of 84-85%, but there was slight intercostal in-drawing. Echocardiography revealed single ventricle with common atrio-ventricular (AV) valve, rudimentary left ventricle, high ostium secundum atrial septal defect and severe pulmonary arterial hypertension with right ventricular systemic pressures of 80 mm Hg [[Figure 1] and Video 1]- . With diagnosis of single ventricle physiology, we took the child off oxygen support to try to restore the ratio of pulmonary and systemic vascular resistances to preoperative levels. The child was comfortable at SpO 2 levels of around 85-86%. ABG on room air revealed a PO 2 of 52 mm Hg, PCO 2 of 42 mm Hg and no acidosis.
Figure 1: Echo showing short-axis view of common AV valve
The presence of CHD should be carefully considered and looked for during preoperative evaluation, whenever an infant presents for surgery for any congenital defect. The need for a careful and precise preoperative evaluation can never be overemphasized in these infants.
Considering that significant cardiac disease is usually symptomatic in early life with most CHD identified before 3 months of age,  .the fact that this infant had tolerated such a complex CHD without demonstrating any major symptoms was quite remarkable. Cardiac murmurs in a tachycardic, crying infant may be difficult to perceive. In dark-skinned persons, central cyanosis may not be detected until the SpO 2 has declined to 75%.  .Since the child was comfortable at SpO 2 levels of 85-86%, significant clinical cyanosis was masked.
A pulmonary-to-systemic blood flow ratio of approximately 1.3:1, SpO 2 between 80 and 85% due to the mixing of systemic and pulmonary venous return, and a hematocrit of 45-50% are considered optimal in this group of patients.  .Unaware of the exact nature of the cardiac lesion, the realization that the child was having some kind of unrestrictive intracardiac shunt led us to adopt an approach of balancing systemic hemodynamics along with acceptance of lower SpO 2 levels by decreasing the inspired oxygen concentration.
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