Is there a use for ketamine in benzodiazepine-resistant status epilepticus?
Status epilepticus (SE) presents a risk of high mortality or functional impairment for a large percentage of patients. In paramedic practice, benzodiazepines are the first-line treatment for SE, but what happens when they fail to work? For most paramedics, the option will be rapid evacuation to an appropriate receiving centre, but this creates additional risks. That being the case, a second intervention may be of benefit to a small number of patients.
Basic science data suggests that ketamine may be a useful adjunct to benzodiazepines in these cases. In 2016, a large United States emergency medical services (EMS) agency introduced a protocol to administer ketamine for midazolam-resistant SE. The study observed how often clinical seizures were terminated using this modified approach in both adults (age ≥18 years) and children/adolescents. Patients were also observed for ketamine-attributable complications. The protocol specified 100 mg intravenous/intraosseous/intramuscular or intranasal ketamine for adults and adolescents, and 1 mg/kg intramuscular/intranasal for younger children when seizures persisted despite sufficient midazolam dosage.
Of 2098 seizure cases during the study period, 72 received the midazolam plus ketamine protocol (57 adults [18-to 86-year-old] and 15 adolescent/children), while a further nine patients (8 adult and 1 child) received ketamine without prior midazolam for preapproved off-protocol circumstances. Examples of this include patients who had received sufficient midazolam from the family immediately before the arrival of EMS.
Results showed that ketamine rapidly terminated seizures without recurrence throughout prehospital and emergency department arrival phases in 56 of the 57 (98.2%) on-protocol adult events. Among the 15 childhood/adolescent on-protocol cases, ketamine rapidly terminated seizures in 11, but only mitigated abnormal motor activity in four. Two of those were retrospectively identified as non-seizure and two were administered intranasally. Ketamine rapidly terminated seizures in all nine off-protocol incidents (100%). There were no apparent ketamine-induced complications.
This study suggests that ketamine appeared to be consistently effective in treating patients with midazolam-resistant SE.
Is your pre-alert practice the same as everybody else's? No seems to be the answer
Pre-alerting a receiving centre can be key to the outcome for certain critical patients – but how well it is used is questionable. In England, more than 1 in 10 ambulance conveyances provide pre-alerts, but data show deviation in both patients and conditions receiving pre-alerts. In 2020, the Association of Ambulance Chief Executives (AACE) and the Royal College of Emergency Medicine (RCEM) issued joint pre-alert guidance for England, yet most UK ambulance service guidelines vary from that national guidance.
This anonymous national online survey aimed to understand the use of ambulance pre-alerts and inform recommendations for practice and guidance. Participants were recruited through their own trusts and included any clinical member of staff responsible for delivery of a pre-alert. The survey was conducted online and was made accessible for a minimum of 6 weeks at each study site. The survey was divided into five areas covering pre-alert decision-making through to the response by the emergency department. Survey questions incorporated rating scales, multiple- and single-choice tick boxes and text boxes for additional information.
The study included 1298 valid responses from 10 English ambulance services and showed variation in practice at all stages of the pre-alert process. Particular variation was noted where there was no condition-specific clinical pathway for the patient, and text comments showed that some variation was owing to the requirements of the receiving emergency department. One-third of respondents always used mnemonics to guide a pre-alert (e.g. ATMIST), but >10% reported not using any specific format. The guidance used to identify patients for pre-alert varied between clinicians and ambulance services, with local ambulance service guidance being most used. There was evidence that respondents had a variable understanding of appropriate conditions for pre-alert, with paramedic students specifically wanting additional guidance on trauma in older patients and medical pre-alerts. Only 29% of respondents reported receiving specific pre-alert training, which is something for educators to consider.
This paper has too much information to report in a simple summary, especially as it provides supplementary information on the website. It is an open access paper that is interesting to read and available to everybody.