Anesthetic management of a child with Bardet-Biedl syndrome undergoing post-auricular dermoid excision.

Sir,

Bardet-Biedl syndrome (BBS) is a rare autosomal recessive disorder with pan systemic manifestations characterized principally by obesity, cone-rod dystrophy, postaxial polydactyly, cognitive impairment, male hypogonadotrophic hypogonadism, complex female genitourinary malformations and renal dysfunction.[12] Incidence varies from 1:13,500 in the Middle East to 1:160,000 in the rest of the world. We report anesthetic management of a patient with this very rare syndrome scheduled for an elective surgery.

An 8-year-old boy with BBS was scheduled for post-auricular dermoid excision. On pre-anesthetic evaluation, there were delayed developmental milestones in the early childhood with reduced ability to communicate and cooperate because of mental retardation. History of obstructive sleep apnea was positive. On examination, he was obese (body mass index 32 kg/m2) with postaxial polydactyly of both upper limbs, early retinitis pigmentosa on fundoscopic examination and post-auricular dermoid, enlarged adenoids and tonsils on otorhinolaryngological examination. Airway assessment revealed short fatty neck, relatively small mouth, large tongue and modified Mallampati score of 3. The peripheral veins were not visible. Cardio respiratory parameters were normal. Patient had hemoglobin 9.3 g/dl, glucose 105 mg/dl, urea 40 mg/dl, creatinine 1.2 mg/dl with normal electrocardiogram (ECG) and echocardiogram and chest roentgenogram. A written informed consent from his parents for the operation was taken. He was pre-medicated with oral midazolam 0.5 mg/kg 30 min prior to surgery. The difficult airway cart was kept ready. With all standard monitors, general anesthesia was induced with O2, N2O and sevoflurane with no difficulty in mask ventilation. Intravenous access was secured with a 22G cannula on the dorsum of the left hand. Fentanyl 50 mcg and atracurium 15 mg were administered intravenously to facilitate intubation. Laryngoscopy revealed a grade 2 Cormack and Lehane view of the larynx. The trachea was intubated with a size 5.0 mm endotracheal tube. Anesthesia was maintained with sevoflurane in 50% O2 in N2O. The surgery lasted for 45 min and the intraoperative course was uneventful. After completion of the operation, the neuromuscular blockade was adequately reversed and the trachea was extubated when patient was fully awake. Post-operative period was uneventful.

Obesity is the cardinal feature of this syndrome present in about 85-90% of these patients. We had predicted difficult intubation in our patient since our patient had short thick neck and a Mallampati score of 3. A difficult airway trolley was kept ready, but fortunately we did not have any problem in the intubation. Facial and dental abnormalities can create difficulties in the mask ventilation during the anesthesia and the abnormalities seen in the epiglottis like bifid epiglottis can also create an intubation difficulty.[3]

Hypertension (50% patients), diabetes mellitus (32% patients), heart diseases(inter-ventricular septal hypertrophy and dilated cardiomyopathy in 50% patients, valvular stenosis, patent ductus arteriosus (PDA) and renal diseases (cystic tubular defects, end stage renal disease, urinary concentration defects, anatomic malformations) are the other anesthetic problems associated with this syndrome.[4] Our patient did not have cardio renal abnormalities. It is judicious to consider ECG and echocardiogram during the pre-anesthetic assessment to rule out cardiac abnormalities. Renal disease is a major cause of morbidity and mortality. So, these patients require careful administration of nephrotoxic agents, fluids and serial monitoring of renal parameters.[5]

One of the challenging aspects of this disease is severe mental retardation. They should be pre-medicated with close monitoring. One should be careful in using the sedative pre-medication in these patients with severe obesity.

Anesthetic technique and drug selection depends on the site of surgery and patient status. Both general and regional anesthesia has been used safely in these patients.[5]

Patient with this rare syndrome with pan systemic manifestations require multiple anesthesia services for both diagnostic and therapeutic procedures. So, proper pre-operative assessment and preparedness to manage the potential problems posed by these patients allows a safe perioperative period.