A case of single atrium and single ventricle physiology with bilateral cleft lip and palate for lip repair surgery.

Bilateral cleft lip and palate may occasionally be associated with complex congenital cyanotic heart disease. An infant with common atrium and single ventricle with infundibular pulmonary stenosis (Blalock-Taussig shunt done recently) presented for lip repair surgery. Balanced general anesthesia was administered using sevoflurane along with a regional nerve block to maintain optimal pulmonary and systemic vascular resistance.

Introduction

Cleft lip and palate are one of the commonest congenital craniofacial abnormalities seen in infants. Complex congenital cyanotic heart disease (CCCHD) is occasionally associated and may pose several anesthetic problems perioperatively. We present a case of complete bilateral cleft lip and palate with congenital cyanotic heart disease [common atrium, single ventricle and infundibular stenosis, with a recently done Blalock–Taussig (BT) shunt] for lip repair surgery.

Case Report

A 6.5-kg, 11-month-old girl with bilateral complete cleft lip and palate was scheduled for cheiloplasty. She had a history of cyanotic spells since birth and her echocardiography revealed common atrium, common atrioventricular valve, single ventricle (right ventricle predominant) along with infundibular pulmonary stenosis with a gradient of 80 mmHg. Right modified BT shunt, subclavian artery to pulmonary artery (PA) was done 2 months back using a 4-mmsynthetic graft. She was symptom-free after surgery and had no history of failure. One day prior to surgery, during an attempt at intravenous (iv) access in the ward, she was noticed to have cyanosis following excessive crying, though it settled subsequently. Her oxygen saturation (SpO2) on room air was 90% and hemoglobin was 17.5 mg/dl, but the other hematological and biochemical investigations were normal. The chest radiograph showed a cardiothoracic ratio of 0.5 and a repeat echocardiograph confirmed shunt patency. The main PA was 8 mm, right PA 6.5 mm, and left PA 5.5 mm in diameter and the pressure gradient across pulmonary valve was 70 mmHg. There was no change in left ventricular size and there was evidence of mild common atrioventricular valve regurgitation.

The child was on aspirin which was discontinued 5 days prior to surgery. Written and informed high risk consent was taken from the parents before surgery. The child was fasting as per standard guidelines and 25 ml/kg ringer lactate was given for 6 h before surgery. The child was premedicated with oral midazolam 0.5 mg/kg, following which she was quiet and could be taken inside the theatre comfortably. The monitoring included SpO2, electrocardiography, and noninvasive blood pressure. Infective endocarditis prophylaxis was given (ceftrixone 50 mg/kg iv). A difficult airway cart was kept ready. Anesthesia was induced by inhalation of 5–6% sevoflurane in oxygen. Mask ventilation was adequate and a check laryngoscopy confirmed Cormack Lehane-1 status. Trachea was intubated with a 4-mm ID uncuffed armoured tube using vecuronium 0.1 mg/kg. Oxygen–nitrous oxide 50:50 mixture, sevoflurane 1-2%, and fentanyl 2 mcg kg were used for maintenance. End-tidal carbon dioxide (EtCO2) was maintained between 32 and 35 mmHg and SpO2 was 80–88% during the surgery. Utmost care was taken to prevent air bubble to enter IV lines. A vasopressor (phenylephrine) and a beta-blocker (esmolol) were kept ready for emergency use.

Bilateral infraorbital nerve block was given by the extraoral approach with 24G needle using 0.5 ml of 0.5% bupivacaine on each side before the commencement of the surgery. Rectal paracetamol was also used (loading dose 40 mg/kg, followed by 20 mg/kg 6-hourly). The child developed bilateral infraorbital hematoma few hours after shifting to the ward. However, it resolved spontaneously after 2 days. Aspirin was restarted thereafter.

Discussion

In patients with common atrium and single ventricle, there is mixing of arterial and venous blood in common cardiac chamber along with decreased pulmonary blood flow due to infundibular stenosis. The creation of a BT shunt increases the pulmonary blood flow and this palliative measure reduces physiologic derangement whenever definitive surgery cannot be done.[1]

Adequate systemic vascular resistance (SVR) should be maintained to ensure adequate pulmonary blood flow. The changes in pulmonary vascular resistance (PVR) are unlikely to make much difference in determining the pulmonary blood flow as the shunt acts as a fixed resistor. Nitrousoxide use would not have affected PVR significantly in this case.

Adequate premedication must be administered to avoid cyanosis due to excessive crying while ensuring that over sedation is not there. Ketamine is often recommended for induction as it improves oxygen saturation by increasing pulmonary blood flow. It was not used in this case since difficult airway was anticipated. Anesthesia was induced with sevoflurane as it has minimal impact on hemodynamic stability and myocardial function. It rarely causes arrhythmias and has rapid induction and emergence qualities. An alpha-agonist like phenylephrine may be used to increase the SVR if required.[2]

SpO2 has limited accuracy below 70% but is relatively reliable between 70 and 90%[3] (80–88% in our case). Adequate hydration is required to prevent thrombosis in patients with polycythemia. Meticulous care should be taken at all times to prevent air bubbles in infusion tubing to prevent systemic air embolization. Regional nerve block enhances intra and postoperative analgesia and decreases anesthetic requirements and postoperative analgesics.[4] Our patient developed hematoma following the nerve block despite the use of a fine needle for injection and stoppage of aspirin well in time. The patients with congenital cyanotic heart diseases are known to have coagulopathy which may have lead to the development of a hematoma.

Anesthetic management of a case of bilateral cleft lip with CCHD should include optimalmanagement of airway,ventilation and SVR. Use of regional nerve blocks is recommended in the management of patients with CCHD.