Anaesthetic management in a child with frontonasal encephalocele.

Dear Sir,

Frontonasal encephaloceles are uncommon congenital malformations, observed more commonly in south-east Asia.1 It involves herniation of intracranial contents from foramen caecum to the junction of nasal and frontal bones, presenting as a nasal mass. Apart from inherent anaesthetic implications of paediatric patients and associated systemic abnormalities; difficulty in securing the airway makes encephalocele repair more challenging for the anaesthesiologists.23

A 3-yr-old male, weighing 10 kg, was admitted with a large frontonasal, lobulated swelling (10°8 cm2 diameter). An MRI of brain revealed large midline anterior calvarial defect at basifrontal and frontonasal region (Fig. 1). Large encephalocele sac was formed, with frontal lobes of brain herniated anteriorly; and a large arachnoid cyst in right frontal region compressed brain parenchyma. A diagnosis of anterior encephalocele was made and the child was posted for excision and repair. During preanaesthetic check-up, difficult mask ventilation was anticipated, as the base of nose was occupied by the irregular shaped, uneven swelling. There were doubts on achieving a perfect seal with face mask. Moreover, blockade of nose with encephalocele ruled out any possibility of nasal intubation if needed. On the day of surgery, the child was premedicated with oral atropine 40 μg/kg, one hour before induction of anaesthesia. The child was calm, enabling peripheral intravenous access before induction. A face mask size # 0 was placed over mouth and nasal alae (Fig 2A) for oxygenation. Anaesthesia was induced with fentanyl 20 μg/kg and sleep dose of propofol (20 mg). Appropriate size of oropharyngeal airway was kept ready in case of difficult mask ventilation. However, a perfect seal was achieved, and ventilation with positive pressure was ensured. Rocuronium 10 mg was given to facilitate tracheal intubation with direct laryngoscopy and a size # 4 tracheal tube (Fig. 2B). Mechanical ventilation was instituted and anaesthesia was maintained with O2 / N2O, sevoflurane and intermittent doses of rocuronium. The 3 hours surgical course was uneventful. At the end of surgery, trachea was extubated and the child was shifted to intensive care unit (ICU) for further management.

Figure 1

MRI of brain showing large midline anterior calvarial defect at basifrontal and frontonasal region with anteriorly herniated frontal lobe

Figure 2

Mask ventilation (A), and placement of tracheal tube (B) in adjustment with anterior encephalocele

There are many reports of difficult mask ventilation and tracheal intubation in patients with occipital (posterior) encephalocele. However, problems while securing airway in children with anterior (frontonasal) encephalocele has hardly been described. In this case, we were able to secure an IV access before induction. Otherwise, inhalational induction of the child with bilateral nasal blockade could have been difficult. The other concern was to avoid compression of encephalocele that could have raised the intracranial pressure and even, rupture of associated frontal arachnoid cyst. Skin covering over the encephalocele may thin out and rupture, leading to exposure of brain, haemorrhage, CSF loss, meningitis, convulsions and even death.4 The anaesthesiologists in such cases have to implement novel and safe ideas.