Inhaled Volatiles for Status Asthmaticus, Epilepsy, and Difficult Sedation in Adult ICU and PICU: A Systematic Review

Abstract

OBJECTIVES: Inhaled volatile anesthetics support management of status asthmaticus (SA), status epilepticus (SE), and difficult sedation (DS). This study aimed to evaluate the effectiveness, safety, and feasibility of using inhaled anesthetics for SA, SE, and DS in adult ICU and PICU patients. DATA SOURCES: MEDLINE, Cochrane Central Register of Controlled Trials, and Embase. STUDY SELECTION: Primary literature search that reported the use of inhaled anesthetics in ventilated patients with SA, SE, and DS from 1970 to 2021. DATA EXTRACTION: Study data points were extracted by two authors independently. Quality assessment was performed using the Joanna Briggs Institute appraisal tool for case studies/series, Newcastle criteria for cohort/case–control studies, and risk-of-bias framework for clinical trials. DATA SYNTHESIS: Primary outcome was volatile efficacy in improving predefined clinical or physiologic endpoints. Secondary outcomes were adverse events and delivery logistics. From 4281 screened studies, the number of included studies/patients across diagnoses and patient groups were: SA (adult: 38/121, pediatric: 28/142), SE (adult: 18/37, pediatric: 5/10), and DS (adult: 21/355, pediatric: 10/90). Quality of evidence was low, consisting mainly of case reports and series. Clinical and physiologic improvement was seen within 1–2 hours of initiating volatiles, with variable efficacy across diagnoses and patient groups: SA (adult: 89–95%, pediatric: 80–97%), SE (adults: 54–100%, pediatric: 60–100%), and DS (adults: 60–90%, pediatric: 62–90%). Most common adverse events were cardiovascular, that is, hypotension and arrhythmias. Inhaled sedatives were commonly delivered using anesthesia machines for SA/SE and miniature vaporizers for DS. Few (10%) of studies reported required non-ICU personnel, and only 16% had ICU volatile delivery protocol. CONCLUSIONS: Volatile anesthetics may provide effective treatment in patients with SA, SE, and DS scenarios but the quality of evidence is low. Higher-quality powered prospective studies of the efficacy and safety of using volatile anesthetics to manage SA, SE, and DS patients are required. Education regarding inhaled anesthetics and the protocolization of their use is needed.

Volatile gas scavenging in the paediatric intensive care unit: Occupational health and safety assessment

“…The awareness of volatile agents and potential therapeutic benefits in paediatrics is well described. 21,22 Historically, the most common indication for the use of volatile gases in paediatric critical care has been to treat bronchospasm in children with severe status asthmaticus that is refractory to conventional therapies. [22][23][24] It has also been utilized in children who are challenging to sedate 5,6 and as a treatment for refractory status epilepticus.…”

“…21,22 Historically, the most common indication for the use of volatile gases in paediatric critical care has been to treat bronchospasm in children with severe status asthmaticus that is refractory to conventional therapies. [22][23][24] It has also been utilized in children who are challenging to sedate 5,6 and as a treatment for refractory status epilepticus. 25 While the use of volatile agents in paediatrics has existed for many years, the widespread adoption or availability of this therapy in the critical care environment has been limited by equipment and trained operators.…”

“…25 While the use of volatile agents in paediatrics has existed for many years, the widespread adoption or availability of this therapy in the critical care environment has been limited by equipment and trained operators. 21,22 The availability of miniature vapourizing devices that are compatible with ICU ventilators has sparked a resurgence of clinical interest in this therapy. The use of these devices remains limited in paediatrics, with limited practice guidance on scavenging safety, given the specific needs of placing the device on the the ventilator inspiratory limb with need for higher infusion rate of volatile agents and active humidification.…”