Anesthetic Management in a Huge Hydrocephalus

Abstract

The pediatric age group with massive hydrocephalus posted for ventriculoperitoneal (VP) shunt presents a lot of confrontation to anesthesiologists due to macrocephalus and associated congenital anomalies. Here, we presented a case report with massive hydrocephalus with aqueduct stenosis, posted for VP shunt placement, and retained a difficult airway.

INTRODUCTION

Hydrocephalus is a disorder of abnormal cerebrospinal fluid (CSF) accumulation in the ventricles that leads to ventricular dilation and increased intracranial pressure (ICP). It is derived from the Greek word hydro, which means “water” and cephalus means “head,” a condition in which there is an imbalance between CSF formation and absorption, resulting in excessive accumulation of CSF in ventricles.

In the modern era, the survival rate in hydrocephalus patients has increased owing to modern treatment facilities. Anesthetic considerations in pediatric patients with hydrocephalus are often intricate due to the abnormally large head, rendering it difficult to anticipate bag and mask ventilation (BMV) and intubation. A meticulous preoperative assessment is essential, including history taking, current clinical symptoms, physical examination, and difficult airway assessment. Primary surgical treatment is CSF diversion. Here we present anaesthetic management of a case of 2 year old child with large hydrocephalus. A written informed consent had been taken from the legal guardian.

CASE REPORT

A 2-year-old second-born child was delivered by cesarean section and cried instantly after birth. He had no perinatal complications.

He presented with a history of gradually increasing head size for 8 months. No history of vomiting, fever, or seizures; No focal neurological deficit. On examination, vital parameters were stable and the “setting sun sign” [Figure 1] was present. Occipitofrontal circumference: 81 cm (normal 32–35 cm), weight: 12 kg and scalp veins dilated. Feeding was well tolerated. The pupils of both eyes were approximately 3.5 cm in diameter and reacting to light. He possessed delayed milestones.

Figure 1.

Setting sun sign

Noncontrast computed tomography brain suggested that all the ventricles are maximally dilated with severe atrophy of brain parenchyma, including cerebellum and basal ganglia. The bony calvarium is grossly dilated [Figure 2]. Other investigations were normal.

Figure 2.

Computed tomography scan of hydrocephalic child showing dilation of the ventricle and cerebral atrophy

This baby was scheduled for ventriculoperitoneal shunt surgery. In our case, the problems we foresaw were “difficult BMV and intubation” due to gross macrocephalus, positioning of the baby for intubation, and the risk of hypothermia.

We kept the difficult airway cart ready. Here, even though the possibility of difficult intubation was due to an abnormally large head circumference, the patient’s position was important. We kept two folded blankets below the body of the child, whereas the head was directly placed over the table, such that the body had come to the level of the head, which facilitated easy intubation [Figure 3]. After shifting the patient to the operating room (OR), all basic monitors such as temperature probe, electrocardiogram, oxygen saturation, respiration rate and blood pressure attached, and baseline vital parameters were recorded. After securing the proper IV line (24G), an injection of glycopyrrolate 0.1 mg was given. Induction with sevoflurane was carried out while preserving spontaneous respiration.

Figure 3.

The patient’s positioning and effective bag and mask ventilation

After checking effective BMV, an injection of propofol 20 mg and injection of atracurium 6 mg were given. After performing 3 min BMV, video laryngoscopy was done with blade number 1, Cormack and Lehane grade was I, and intubation was done with 4.5 mm uncuffed endotracheal (ET) tube [Figure 4]. ET tube was fixed at 10 cm, and B/l air entry was checked.

Figure 4.

Videolaryngoscopy-assisted intubation

General anesthesia was maintained with oxygen, nitrous oxide, and sevoflurane at 3 L/min, as well as intermittent maintenance doses of atracurium.

A right-sided ventriculoperitoneal shunt was done. A “Chabra” shunt was placed, and the CSF leak was properly checked by the “Valsalva maneuver.”

After surgery, the inhalational agent was cutoff. When spontaneous respiration of the patient came, then it was reversed with an injection “neostigmine 0.5 mg and glycopyrrolate 0.1 mg.” Then, the patient was extubated and put on a facemask at 5 L/min. Upon follow-up in the next day patient was doing fine as shown in Figure 5.

Figure 5.

Postoperative case of ventriculoperitoneal shunt placement

DISCUSSION

Hydrocephalus can be congenital and acquired. It results from overproduction, impaired circulation (obstructive type), or underabsorption of CSF. The most common cause of congenital hydrocephalus is impaired circulation, caused by structural abnormalities such as “aqueductal stenosis,” tumors, and malformations; such as Arnold–Chiari malformation or arachnoid cysts or Dandy–Walker malformation. The most common genetic form is X-linked hydrocephalus due to aqueductal stenosis, affecting 10% of males. Hydrocephalous due to decreased CSF absorption is very rare and is seen mostly after central nervous system infection, which leads to inflammation of subarachnoid villi, for example, TORCH infection.

The CSF is a clear and colorless fluid in the subarachnoid space that cushions and protects the spinal cord and brain. It provides protection and nourishment and helps in waste removal. It is produced by the ‘Ependymal cells of the choroid plexus, located in lateral ventricles.[1] It flows from the lateral ventricle to the third ventricle through the foramen of Monro, from where it drains into the fourth ventricle through the aqueduct of Sylvius.[2] Any disturbance in the normal production, flow, and absorption leads to CSF accumulation and increased ICP with resultant ventriculomegaly. This can damage brain parenchyma due to raised ICP, and in severe conditions, death may occur.[3]

Clinical features of hydrocephalus before the closure of the cranial sutures (before 18–24 months) are macrocephaly with cranial bone separation, an anterior fontanelle that may be full or bulging, gradually increasing the head circumference, a sunsetting sign (an impaired ability to upward gaze due to midbrain compression), prominent scalp veins, delayed milestones, poor feeding, and growth failure. In our case, the patient presented with a sunsetting sign with delayed developmental milestones.

The challenges we had were mainly difficulty with mask ventilation, difficult intubation, postoperative hypoxia, and delayed reversal. We planned for spontaneous ventilation before induction as it had the advantages of maintaining spontaneous ventilation during induction of general anesthesia, and preserving pharyngeal muscle tone; therefore, maintaining upper airway patency and ventilation.[4] However, the disadvantages of it were coughing, laryngospasm, bronchospasm, and intubation failure.

If we fail to achieve access to the airway, then the backup plan was to place a supraglottic device for ventilation, such as a laryngeal mask airway or oropharyngeal airway with BMV, and wait for the return of spontaneous respiration. Large heads posed serious problems during laryngoscopy. Placing a stack of blankets in the back, up to the shoulder, puts the larynx in the line of visual axis making intubation easier.

Other challenges encountered during recovery from anesthesia were bronchospasm, prolonged sedation, delayed recovery, and generalized hypotonia.[5] Premedication with an injection of glycopyrrolate reduced secretions as well as also provided broncho protection.[6] Analgesia is another vital component and that was achieved by injection of fentanyl. Short-acting opioids such as remifentanil, sufentanil, and fentanyl should be preferred for smooth and rapid emergence. There is a rapid fluid shift after drainage of CSF. Sudden decompression may lead to impaired cerebral perfusion. To maintain adequate cerebral perfusion, the maintenance of isovolemia, iso-osmolarity, and iso-oncotic blood volume is mandatory. We managed with the infusion of warm half-normal saline. The baby was maintained in normothermia and provided with ambient OR temperature. Toward the end, we completely reversed the patient from a neuromuscular blocking agent without any residual paralysis and achieve baseline neuromuscular tone.

Congenital hydrocephalus is sufficient to produce brain parenchymal atrophy; hence, it is often associated with severe mental retardation. Other signs may be due to pressure effects, such as papilledema, bradycardia, systemic hypertension, endocrine disturbances, and fluid and electrolyte abnormality. In our case, other adjuvant signs were not evaluated. Cushing’s triad, consisting of bradycardia, irregular respirations, and widened pulse pressure, was not seen in our case. In this case, the baby had mental retardation and delayed milestones due to brain parenchymal atrophy and growth failure.

Persistent vomiting, hypovolemia, hypotension, and electrolyte disturbances may also occur. Our goal in fluid management was to maintain adequate hydration and cerebral perfusion with half-normal saline without causing hyperglycemia.

CONCLUSION

The anesthetic management of a child with huge hydrocephalus shows a lot of confrontation due to macrocephalus, a difficult airway, the pediatric age group, the patient’s position during anesthesia, the risk of hypothermia, and congenital anomalies. Proper positioning of the child is essential for successful intubation.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.