Late-presenting bilateral congenital diaphragmatic hernia: An extremely rare confluence of two rarities.

INTRODUCTION

Congenital diaphragmatic hernia (CDH) occurs in 1 in 2000–4000 live births.[1] Herniation of abdominal organs into the thorax is associated with varying degrees of pulmonary hypoplasia and pulmonary vascular abnormalities, which chiefly determine the prognosis.[2] Bilateral Bochdalek hernias are very rare and have a very poor prognosis. Late-presentation of CDH (after the neonatal period), which is also uncommon, has a better prognosis than CDH presenting in the neonate. We present anaesthetic perspectives of an extremely unusual late-presenting bilateral CDH.

CASE REPORT

A 45-day-old female child presented with history of rapid breathing and poor feeding for 1 week. The patient was born out of a non-consanguineous marriage, by normal vaginal delivery at term. Her birth weight was 3.03 kg, and her Apgar scores were 9 and 10 at 1 and 5 min respectively. The mother's antenatal care was performed elsewhere, and she came to our centre only for delivery. She did not report any antenatal ultrasound scans. There was no record of any dyspnoea being noticed during the immediate post-natal period. The patient and mother were discharged on the 3rd day after delivery.

On examination, child was dyspnoeic with a respiratory rate of 84 breaths/min and intercostal retractions, but her oxygen saturation (SpO2) was 98% on room air and 100% with oxygen head-box. The heart rate was 170 beats/min, peripheries were cold and the child appeared dehydrated. Breath sounds were decreased on the right-side, and liver was not palpable per abdomen. The child's weight was 2.96 kg. A chest radiograph showed bowel loops in the right hemithorax and mediastinal shift to the left suggesting a diagnosis of right-sided CDH.

While the child was in respiratory distress, the oxygenation was adequate, allowing time for preparation. After providing oxygen via a tight-fitting mask without positive pressure bag ventilation, intravenous midazolam was given before trachea was intubated, nasogastric tube inserted, and patient shifted to paediatric intensive care unit (ICU) for stabilisation. A computed tomography showed bilateral CDH with kidney and bowel being the contents on the right, and spleen and gastric fundus on the left [Figure 1]. The liver was in normal position. An echocardiography done to rule out associated cardiac anomalies proved grossly normal, but no mention was made of pulmonary pressures. ICU management included fluid resuscitation, antibiotics for possible respiratory infection, mechanical ventilation (pressure-controlled synchronised intermittent mandatory ventilation, positive end-expiratory pressure 5 cm H2O, positive inspired pressure 12 cm H2O, rate 30/min, inspired oxygen concentration [FiO2] 40%), and morphine-midazolam infusion for sedation.

Figure 1

Note the right kidney (x) and spleen (*) in the thoracic cavity

Patient was shifted to the operation theatre. Initial ventilator settings were as from ICU, subsequently adjusted to maintain end-tidal carbon dioxide (ETCO2) at 30–35 mm Hg. Electrocardiogram, non-invasive blood pressure, SpO2, ETCO2, anaesthetic gas concentration and temperature were monitored. Anaesthesia was maintained with isoflurane in an air-oxygen mixture (FiO2 60%), analgesia with boluses of fentanyl, and relaxation with boluses of atracurium. Patient had two 24-gauge peripheral intravenous access whose patency was confirmed. Maintenance fluid requirements were satisfied with 12 mL/h of 0.45% saline with 5% dextrose. Third space losses were replaced with Ringer's Lactate and blood loss with plasma and packed cells. Temperature was maintained using a forced air warming device.

During the 3 h laparotomy, both diaphragmatic defects were closed primarily. The contents on the right included kidney, ascending colon and small bowel; while on the left were the spleen and splenic flexure of the colon. The abdomen was closed primarily as the surgeons felt the rise in intra-abdominal pressure would not be deleterious. The patient was haemodynamically stable and did not have any desaturation.

After the surgery, the patient was returned to ICU for post-operative ventilation [Figure 2]. She had a prolonged recovery. Trachea was extubated on the third post-operative day, but patient required intermittent nasopharyngeal continuous positive airway pressure for 2 weeks before being well enough to be shifted to the ward. She needed oxygen via face mask for 12 more days. She was discharged in good condition on the 33rd day from admission. She was stable on follow-up 2 months after discharge.

Figure 2

Post-operative chest radiograph

DISCUSSION

The prognosis in CDH depends on the degree of pulmonary hypoplasia and pulmonary hypertension.[2] The timing of surgery is unrelated to survival.[3] Thus, patients are no longer rushed for emergency surgery in the hope of expanding collapsed lung segments. Instead, they undergo a period of pre-operative stabilization.

Bilateral hernias are extremely rare (0.9% of all live-born CDH) and usually have a poor prognosis[4] due to severe pulmonary impairment, and more associated anomalies.[24] Late presentation, defined as CDH presenting outside the neonatal period, is also rare (2.6% of all live-born CDH).[5] However, these have a very good prognosis. In one series, there was 100% survival for late-presenting CDH.[5] The late presentation itself is perhaps a reflection of the minor nature of pulmonary impairment that allows the patient to remain asymptomatic longer on room air. In two analyses, only 1 in 79 (1.2%),[5] and 4 in 362 (1.1%)[6] cases of late-presenting CDH had bilateral pathology. This suggests that the incidence of a late-presenting bilateral CDH would be around 1–2/12.8 million live-births, making it the rarest of rare occurrences.

The hallmarks of good perioperative management reflected in this case are: Avoidance of bag-mask ventilation which can cause further pulmonary impairment by gastric dilatation; early nasogastric tube insertion for gastric decompression; pre-operative stabilisation including ventilation to optimise cardio-respiratory function;[3] avoiding barotrauma and pneumothorax[7] (classically of the contralateral lung) by limiting peak inspiratory pressures up to 25 cm H2O; using the lowest possible FiO2 to maintain pre-ductal saturation above 85%;[1] and optimum sedation to prevent sympathetic-mediated rise in pulmonary vascular pressures.[8]

CONCLUSION

The challenges we faced in this case were the extreme rarity of the condition, a very small infant needing fine balancing of fluid and haemodynamic status, careful airway and ventilator management, and prolonged respiratory support. Sticking to sound principles of perioperative management resulted in a good outcome.