P2A224: The Use of Isoflurane in the Pediatric Intensive Care Unit to Reduce Long Term Sedation Needs and Associated Morbidity

Introduction: Isoflurane is a potent inhaled anesthetic agent and is used in pediatrics to manage refractory status asthmaticus and status epilepticus. Less commonly, isoflurane has been used as a sedative adjunct in the intensive care unit (ICU) during complex sedation management. There is a lack of data about the risks and benefits of this therapy in pediatrics to inform clinical practice.

Case Description: Patient is a 6 month old child with congenital diaphragmatic hernia who was cannulated to venoarterial extracorporeal membrane oxygenation (VA-ECMO) on day of life 0 in the setting of acute hypoxic respiratory failure. He remained cannulated for 43 days. His course was complicated by multiple embolic/ischemic strokes with resultant seizures, dysautonomia, severe pulmonary hypertension and pulmonary hypoplasia. He required prolonged mechanical ventilation and had chronic sedation needs requiring escalation of multimodal regimen to capture agitation. His chronic dependence and clinical lability prevented successful deescalation of medications. He required high doses of fentanyl (11.5 mcg/kg/hr), ketamine (20 mcg/kg/min) dexmedetomidine (2 mcg/kg/hr), pentobarbital (23 mg q 4hrs) and lorazepam (1.25 mg q 4hrs). Due to intolerance of sedative weans, an isoflurane washout was conducted to minimize morbidity, minimize ICU and hospital length of stay, and work to rehabilitate and promote neurocognitive development of the patient.

A starting dose of 0.5% isoflurane was titrated to a maximum dose of 1.7% to achieve the desired level of sedation which allowed for cessation of ketamine, fentanyl, dexmedetomidine, pentobarbital, and lorazepam. Isoflurane washout was conducted for a total of 17 days. The patient was able to extubate on the day of cessation of isoflurane. He remained on 2 L of nasal cannula for respiratory support and has remained off all sedatives and analgesics.

Discussion: The burden of prolonged sedation and severe pulmonary hypertension posed the risk for increasing morbidity, potential technology dependence (tracheostomy), increased ICU and hospital length of stay, and inability to initiate rehabilitation and promote neurocognitive development. This case is an example of the opportunities presented by employing an isoflurane washout in a particular subset of complex pediatric patients with significant sedation dependence. After an isoflurane washout, the patient was able to discontinue all sedatives and analgesics, extubate, and rehabilitate after a prolonged period of sedation and mechanical ventilation.

Conclusion: The use of inhaled anesthetics as an adjunctive therapy in the ICU is not commonly employed in pediatrics due to a lack of evidence. Further research is needed to determine the long-term neurologic outcomes associated with prolonged use of inhaled anesthetics. In the future, evidence-based protocols and best practice guidelines that include the utilization of inhaled anesthetics as an adjunctive therapy for complex sedative management in the ICU will allow practitioners to safely implement this treatment option into their practice.