Dextrocardia and ventricular septal defect with situs inversus: Anesthetic implications and management.

The patients with complicated congenital heart diseases are reaching adulthood with advances in corrective surgeries and medical management. Impact of anesthetic agents on complex cardiac and extra cardiac anomalies and presence of previous palliative procedures can be a challenge for the anesthesiologist perioperatively, while these patients present for cardiac/noncardiac surgeries. We report the perioperative management of a patient with ventricular septal defect, dextrocardia, pulmonary hypertension, and situs inversus who underwent a successful hernioplasty and hydrocelectomy with a combined spinal epidural anesthesia. This discussion relates to the anesthetic management in such conditions with a special reference to Kartagener's syndrome.

INTRODUCTION

Dextrocardia can be associated with situs inversus and other cyanotic and acyanotic congenital heart disease including ventricular septal defect. Though the true incidence is difficult to ascertain, very often we encounter these cases in our clinical practice. Anesthesiologists must have a through understanding of the pathophysiology and anesthetic implications that could be faced when anesthetizing these patients.

CASE REPORT

A 38-year-old male presented with left-sided hydrocele and indirect inguinal hernia of long duration. His medical history included repeated upper respiratory tract infection requiring frequent hospitalization in childhood and was diagnosed to have a ventricular septal defect (VSD) and situs inversus at the age of 7 years. On examination, the apical impulse was felt in right 5th intercostal space with right precordial bulge. A holosystolic murmur (Grade 3/6) was heard in the right 2-4th intercostal spaces with a loud P2 and normal vesicular breath sounds. The hemoglobin of 16.3 g/dl and platelets of 2,30,000/mm3 were noted on blood investigations. Chest X-ray showed dextrocardia and a right-sided “stomach bubble” [Figure 1]. Situs inversus of abdominal organs was seen on the ultrasound. Echocardiogram (ECHO) revealed dextrocardia, subaortic VSD, mildly dilated right ventricle and atrium, moderate tricuspid regurgitation, and pulmonary arterial hypertension (60 mmHg). ECG was consistent with mirror image dextrocardia.

Figure 1

Chest X-ray showing dextrocardia and situs inversus

A combined spinal epidural anesthesia (CSEA) was planned for hernioplasty and hydrocelectomy. The patient was premedicated with pantoprazole and ondansetron on the morning of surgery. A 20G arterial line was secured for invasive pressure monitoring. Continuous ECG, invasive blood pressure, and pulse oximeter was instituted. With strict asepsis and the patient in sitting position, an 18-gauge epidural catheter was placed at L1-L2 interspace. Using a 25-gauge spinal needle, subarachnoid block was performed with 1.8 ml of 0.5% bupivacaine and 25 μg fentanyl at L3-L4 interspace. The patient's heart rate, blood pressure, and oxygen saturation remained stable during the intraoperative period. Fentanyl 50 μg and graded doses of 0.2% Ropivacaine was administered epidurally to achieve segmental anesthesia for the subsequent operative period. Further intraoperative course was uneventful. In the first 24 hours postoperatively, patient was monitored in the ICU. Buprenorphine 120 mcg twice daily was administered for epidural analgesia. Further postoperative period was uneventful and subsequently, the patient was discharged home.

DISCUSSION

The commonest form of dextrocardia in adults is with L-loop ventricles and inverted great vessels (situs inversus totalis or the mirror image dextrocardia) present in 1-2 in 20,000 of normal population.[123] Dextroversion is the second most common type of dextrocardia associated with situs solitus, D-loop ventricles, and normal great arteries. Anomalous pulmonary venous return, tetralogy of Fallot, septal defects, pulmonic stenosis, coarctation of the aorta, and corrected transposition of great arteries (TGA) are seen in 90% of these cases.[1] In up to 30% cases, dextrocardia can occur in congenitally corrected TGA. This rare configuration can occur with situs solitus or less commonly situs inversus.[1]

Dextrocardia can also be associated with heterotaxy syndromes of asplenia and polysplenia with a tendency toward noncyanotic congenital heart defects.[13] Kartagener syndrome (KGS) occurs in 25% of individuals who have mirror-image dextrocardia which is characterized by the triad of situs inversus, paranasal sinusitis, and bronchiectasis associated with impaired mucociliary clearance and ciliary dysfunction leading to reduced fertility. The incidence is estimated to be 1-2 per 30,000 with 50% of individuals having situs inversus.[4] Both general anesthesia and regional techniques have been mentioned in these cases. CSEA was described as technique of choice for a patient with KGS who presented with uterovaginal prolapse.[5] A successful general anesthesia was described for lobectomy in an 8-year-old child with KGS by advancing a modified single lumen tube into the left bronchus.[6] Fiberoptic endoscopic sinus surgery and septoplasty,[7] difficult airway management using nasal intubation for sagittal split ramus osteotomy, has been described under general anesthesia.[8] Conversely, a case of prolonged paralysis following the use of succinylcholine has been reported in a patient with situs inversus totalis secondary to anticholinesterase deficiency[9] and ranitidine-induced bradycardia in a patient with dextrocardia.[10]

Preoperatively, the patients may present with varying clinical features from being asymptomatic to dyspnea and cyanosis at rest. Tachyarrhythmias provoking syncopal attacks with or without palliative surgeries may be seen. Drug history may show the use of warfarin, diuretics, and antiarrhythmics with their associated side effects. Complete blood count and coagulation tests are to be monitored for polycythemia and abnormal clotting profile. Recent ECG and Echocardiogram (ECHO) findings are very important to decide about the anesthetic management. ECG may show large peaked P waves, prolonged PR interval, strain/hypertrophy pattern, and Right Bundle Branch Block. The chest X-ray may reveal cardiomegaly, respiratory infection, and poorly perfused lung fields. Paradoxical embolization, bacterial endocarditis, brain abscess, and congestive heart failure may occur.

Premedicant drugs that depress ventilation or ciliary activity should be avoided in dextrocardia associated with KGS. Sedatives should be used with caution as respiratory acidosis may increase pulmonary vascular resistance. Left internal jugular vein cannulation is preferred (to avoid thoracic duct and to ensure direct access to right atrium) in case of inversion of great vessels. The anatomy of the bronchi should be considered before selecting a double lumen tube in thoracic surgery. Uterine displacement is often to the right in parturients. Diligent search should be made for spine and airway malformations.

Impact of anesthetic agents on complex cardiac, extra cardiac anomalies, and previous palliative procedures can be challenging perioperatively. Anesthetic management depends on the presence of shunt, pulmonary hypertension, hypoxemia, ventricular dysfunction, pulmonary flow, and arrhythmia. Induction with inhalational agents is slow in pulmonary hypertension but faster with intravenous agents in right to left shunts. Hyperventilation and 100% oxygenation increases pulmonary congestion in patients with L-R shunt and hence be avoided. Intracardiac catheter insertion may be hazardous as it can provoke serious arrhythmias. Air entering peripheral venous lines may cause paradoxical air emboli. Tachycardia is often poorly tolerated because of pulmonary hypertension. Hypotension and hypoxia increase chances of right-to-left shunt. There is risk of bacterial endocarditis, especially in presence of a central line.

Local and regional anesthetic techniques are preferred over general anesthesia. With the rapidity, density, and reliability of the subarachnoid block and the flexibility of continuous epidural to extend duration of analgesia, CSEA is an effective way to reduce the local anesthetic requirement. The segmental CSEA method can be used to extend the dermatomal block with minimal drugs. Low-dose CSEA with local anesthetic and opioid or low-dose epidural block alone provides effective analgesia with minimal motor and proprioceptive block and reduction in the incidence of postoperative thrombotic episodes. High-risk patients should be observed in the intensive care unit for arrhythmias and cardiac ischemia. Adequate analgesia should be provided to the patients to prevent hemodynamic instability. Meticulous fluid balance is very important to prevent cardiac failure or hypotension. Factors like acidosis and atelectasis that increase pulmonary pressures should be avoided in ventilated patients.

The patients with complicated congenital heart disease which were once thought to be fatal are reaching adulthood with advances in corrective surgeries and medical management. We describe the perioperative management of a patient with VSD, dextrocardia, pulmonary hypertension, and situs inversus who underwent a successful hernioplasty and hydrocelectomy with a CSEA. Though these conditions are rare in occurrence, we still come across cases with complicated cardiac defects, which emphasize the need to be aware of their occurrence and anesthetic implications, particularly in developing countries.