The Effectiveness of Intranasal Midazolam for the Treatment of Prehospital Pediatric Seizures: A Non-inferiority Study

What is the Evidence for Using Intranasal Medicine in the Prehospital Setting? A Systematic Review

OBJECTIVES

Intranasal (IN) medications offer a safe non-invasive way to rapidly deliver drugs in situations where intravenous (IV) access and intramuscular (IM) administration is challenging or not feasible. In the prehospital setting, this can be an essential alternative in time critical situations including trauma management, seizures, and agitated patients. However, there is a paucity of evidence summarizing its efficacy in this environment. This systematic review aims to assess the current evidence supporting the use of IN medicine (midazolam, ketamine, fentanyl, morphine, glucagon, and naloxone) in the prehospital setting alone.

METHODS

A systematic literature search (PROSPERO CRD42023440713) of PubMed, Web of Science, OVID Medline, "Cochrane Central Register of Controlled Trials," Cochrane reviews and Embase was performed from inception to June 2023 to identify studies where IN medications were administered to patients in the prehospital setting. All randomized controlled trials, observational cohort studies, case series, and case reports were included. Papers not written in English, review articles, abstracts, and non-published data (including letters to the editor) were excluded. The methodological quality of the included studies was interpreted using the Cochrane risk of bias tool and rated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. No funding was received.

RESULTS

From 4818 studies, 39 were included (seven for midazolam, five for ketamine, twelve for fentanyl, one for diamorphine, two for glucagon, and twelve for naloxone). A total of 24,097 patients were treated with IN medications across all the studies. There were five moderate quality, four low quality, and thirty very low quality studies. The potential efficacy of IN fentanyl and ketamine was demonstrated consistently throughout the studies with less clear evidence for midazolam, morphine, glucagon, and naloxone. This review was severely limited by the study quality, with most studies demonstrating "high concerns" for bias.

CONCLUSIONS

Prehospital IN medication administration has wide-ranging potential, particularly for administering analgesia. There are likely to be certain populations, for example, pediatrics, that will benefit the most, although conclusions are limited by the quality of evidence currently available. We encourage additional research in this area, particularly with robust prospective double-blind RCTs.

Association of midazolam route of administration and need for recurrent dosing among children with seizures cared for by emergency medical services

OBJECTIVE

National guidelines in the United States recommend the intramuscular and intranasal routes for midazolam for the management of seizures in the prehospital setting. We evaluated the association of route of midazolam administration with the use of additional benzodiazepine doses for children with seizures cared for by emergency medical services (EMS).

METHODS

We conducted a retrospective cohort study from a US multiagency EMS dataset for the years 2018-2022, including children transported to the hospital with a clinician impression of seizures, convulsions, or status epilepticus, and who received an initial correct weight-based dose of midazolam (.2 mg/kg intramuscular, .1 mg/kg intravenous, .2 mg/kg intranasal). We evaluated the association of route of initial midazolam administration with provision of additional benzodiazepine dose in logistic regression models adjusted for age, vital signs, pulse oximetry, level of consciousness, and time spent with the patient.

RESULTS

We included 2923 encounters with patients who received an appropriate weight-based dose of midazolam for seizures (46.3% intramuscular, 21.8% intranasal, 31.9% intravenous). The median time to the first dose of midazolam from EMS arrival was similar between children who received intramuscular (7.3 min, interquartile range [IQR] = 4.6-12.5) and intranasal midazolam (7.8 min, IQR = 4.5-13.4) and longer for intravenous midazolam (13.1 min, IQR = 8.2-19.4). At least one additional dose of midazolam was given to 21.4%. In multivariable models, intranasal midazolam was associated with higher odds (odds ratio [OR] = 1.39, 95% confidence interval [CI] = 1.10-1.76) and intravenous midazolam was associated with similar odds (OR = 1.00, 95% CI = .80-1.26) of requiring additional doses of benzodiazepines relative to intramuscular midazolam.

SIGNIFICANCE

Intranasal midazolam was associated with greater odds of repeated benzodiazepine dosing relative to initial intramuscular administration, but confounding factors could have affected this finding. Further study of the dosing and/or the prioritization of the intranasal route for pediatric seizures by EMS clinicians is warranted.

Prehospital Seizure Management in Children: An Evaluation of a Nationally Representative Sample

OBJECTIVE

To describe the characteristics and emergency medical services (EMS) interventions, appropriateness of medication dosing, and factors associated with use of any or multiple doses of benzodiazepines for children with seizures in the prehospital setting from a nationally representative dataset.

METHODS

We performed a retrospective study of EMS encounters within the National Emergency Medical Services Information System between 2019-2021, including children (<18 years) with an impression of seizures. We identified (1) factors associated with the use of benzodiazepines in a logistic regression model and (2) factors associated with multiple doses of benzodiazepines in an ordinal regression model.

RESULTS

We included 361,177 encounters for seizure. Among transports with an Advanced Life Support clinician, 89.9% were given no benzodiazepines, and 7.7%, 1.9%, and 0.4% were given 1, 2 and ≥3 doses of benzodiazepines, respectively. Encounters given more doses of benzodiazepines had increased use of supplemental oxygen. A high proportion (43.4%) of EMS-provided initial benzodiazepine doses were inappropriately low. EMS-provided benzodiazepine use was associated with use of benzodiazepine prior to EMS arrival. Provision of multiple doses of EMS-provided benzodiazepines was associated with use of a low initial dose of benzodiazepine and use of lorazepam or diazepam compared with midazolam.

CONCLUSION

A large proportion of prehospital pediatric patients with seizure are given inappropriately low dose of benzodiazepines. Use of a low dose of benzodiazepine and use of benzodiazepines other than midazolam are associated with additional benzodiazepine usage. Our findings have implications for future research and quality improvement needs in pediatric prehospital seizure management.

Real-World Midazolam Use and Outcomes With Out-of-Hospital Treatment of Status Epilepticus in the United States

STUDY OBJECTIVE

Guidelines recommend 10-mg intramuscular midazolam as the first-line treatment option for status epilepticus. However, in real-world practice, it is frequently administered intranasally or intravenously and is dosed lower. Therefore, we used conventional and instrumental variable approaches to examine the effectiveness of midazolam in a national out-of-hospital cohort.

METHODS

This retrospective cohort study of adults with status epilepticus used the ESO Data Collaborative research dataset (January 1, 2019, to December 31, 2019). The exposures were the route and dose of midazolam. We performed hierarchical logistic regression and 2-stage least squares regression using agency treatment patterns as an instrument to examine our outcomes, rescue therapy, and ventilatory support.

RESULTS

There were 7,634 out-of-hospital encounters from 657 EMS agencies. Midazolam was administered intranasally in 20%, intravenously in 46%, and intramuscularly in 35% of the encounters. Compared with intramuscular administration, intranasal midazolam increased (risk difference [RD], 6.5%; 95% confidence interval [CI], 2.4% to 10.5%) and intravenous midazolam decreased (RD, -11.1%; 95% CI, -14.7% to -7.5%) the risk of rescue therapy. The differences in ventilatory support were not statistically significant (intranasal RD, -1.5%; 95% CI, -3.2% to 0.3%; intravenous RD, -0.3%; 95% CI, -1.9% to 1.2%). Higher doses were associated with a lower risk of rescue therapy (RD, -2.6%; 95% CI, -3.3% to -1.9%) and increased ventilatory support (RD, 0.4%; 95% CI, 0.1% to 0.7%). The instrumental variable analysis yielded similar results, except that dose was not associated with ventilatory support.

CONCLUSION

The route and dose of midazolam affect clinical outcomes. Compared with intramuscular administration, intranasal administration may be less effective and intravenous administration more effective in terminating status epilepticus, although the differences between these and previous results may reflect the nature of real-world data as opposed to randomized data.