Evaluating the effectiveness of the maximum permitted dose of midazolam in seizure termination: Insights from New South Wales, Australia.

OBJECTIVE: Out-of-hospital seizures demand rapid management. Midazolam plays a key role in stopping seizures. At times the first dose of midazolam proves insufficient, necessitating additional doses. Within the New South Wales Ambulance (NSWA) service, the upper limit for midazolam administration is set at 15 mg. However, the outcomes and safety of using midazolam at this maximum dosage have not been thoroughly investigated. METHODS: A retrospective analysis of out of hospital electronic health records from New South Wales, Australia, over the year 2022, was conducted. The study manually reviewed cases where adult patients received the maximum dose of midazolam for seizure management by paramedics. It focused on seizure cessation success rates and the incidence of adverse effects to evaluate the clinical implications of high-dose midazolam administration. RESULTS: Of 818 790 individual attendances by NSWA clinicians, a total of 11 392 (1.4%) adults had seizures noted, of which midazolam was administered in 2565 (22.5%). An algorithm shows that in 2352 (91.7%) instances the midazolam was associated with the apparent termination of seizures. Analysis revealed that 176 (1.5%) proportion of all adult's seizure patients required the maximum dose of midazolam for seizure control. These higher doses successfully terminate seizures in about half of the instances. AEs following the maximum dose of midazolam included hypoxia in 26.7% of patients and respiratory depression in 9.7%, indicating significant side effects at higher dosages. CONCLUSION: In New South Wales, Australia, administering the maximum dose of midazolam to seizure patients is rare but proves effective in approximately half of the refractory seizure cases. Therefore, assessing the potential for additional doses of midazolam or the use of a second-line agent is advisable.

Crystalloid Fluid Management of Non-Traumatic Hypotension by New South Wales Ambulance.

INTRODUCTION: Shock is circulatory insufficiency, inadequate oxygen delivery, and cellular hypoxia. Intravenous fluids are essential for shock management. Despite treatment, patients can face persistent shock with ongoing hypotension, contributing to higher mortality. This analysis aims to quantify hypotensive non-traumatic cases in an Australian ambulance service, determine persistent hypotension prevalence, and assess paramedic-administered intravascular fluids' impact on blood pressure changes. METHODS: This study is a retrospective analysis of prehospital fluid resuscitation by New South Wales Ambulance paramedics during 2022. Hypotension is defined as a systolic blood pressure of ≤ 90 mmHg, and persistent hypotension is a systolic blood pressure consistently below 90 mmHg across all observations, with a final blood pressure below 90 mmHg. This study aimed to determine the volume of fluid resuscitation at which a plateau in population-level systolic blood pressure response is observed, by calculating the derivative of the fitted logistic regression model. Moreover, this analysis identified the relative contribution of factors influencing the probability of an attempt at intravenous or intraosseous access using machine learning. RESULTS: Among 796,865 attendances, 23,049 (2.9%) involved non-traumatic patients with hypotension. In total 7,388 (32.1%) of the hypotensive cases resulted in persistent hypotension, of which 3,235 (43.8%) received Hartmann's solution and 1,745 (53.9%) received at least 500 ml of fluids but still had hypotension. The model showed that systolic blood pressure tends to stop increasing after 500-600 milliliters of fluid are given. This suggests that, on average, giving more fluid than this may not raise blood pressure further in a prehospital setting, though individual patient needs can differ. The top four factors from the machine learning shows that as initial respiratory rate goes up, the probability of intravascular access rises. Transport times less than 20 min are associated with a smaller chance of access and younger patients are less likely to receive an attempt. Finally, extremes of systolic blood pressure are more likely to receive access attempts. CONCLUSION: This study found that three percent of non-traumatic attendances have at least one episode of hypotension, and that more than half of these have persistent hypotension. Only 44% of persistently hypotensive received fluids, and half of persistently hypotensive patients stayed hypotensive despite a reasonable volume of prehospital crystalloids.

Tranexamic Acid for Traumatic Injury in the Emergency Setting: A Systematic Review and Bias-Adjusted Meta-Analysis of Randomized Controlled Trials.

STUDY OBJECTIVE: Traumatic injury causes a significant number of deaths due to bleeding. Tranexamic acid (TXA), an antifibrinolytic agent, can reduce bleeding in traumatic injuries and potentially enhance outcomes. Previous reviews suggested potential TXA benefits but did not consider the latest trials. METHODS: A systematic review and bias-adjusted meta-analysis were performed to assess TXA's effectiveness in emergency traumatic injury settings by pooling estimates from randomized controlled trials. Researchers searched Medline, Embase, and Cochrane Central for randomized controlled trials comparing TXA's effects to a placebo in emergency trauma cases. The primary endpoint was 1-month mortality. The methodological quality of the trials underwent assessment using the MASTER scale, and the meta-analysis applied the quality-effects method to adjust for methodological quality. RESULTS: Seven randomized controlled trials met the set criteria. This meta-analysis indicated an 11% decrease in the death risk at 1 month after TXA use (odds ratio [OR] 0.89, 95% confidence interval [CI] 0.84 to 0.95) with a number needed to treat of 61 to avoid 1 additional death. The meta-analysis also revealed reduced 24-hour mortality (OR 0.76, 95% CI 0.65 to 0.88) for TXA. No compelling evidence of increased vascular occlusive events emerged (OR 0.96, 95% CI 0.73 to 1.27). Subgroup analyses highlighted TXA's effectiveness in general trauma versus traumatic brain injury and survival advantages when administered out-of-hospital versus inhospital. CONCLUSIONS: This synthesis demonstrates that TXA use for trauma in emergencies leads to a reduction in 1-month mortality, with no significant evidence of problematic vascular occlusive events. Administering TXA in the out-of-hospital setting is associated with reduced mortality compared to inhospital administration, and less mortality with TXA in systemic trauma is noted compared with traumatic brain injury specifically.

Video versus direct laryngoscopy by specialist paramedics in New South Wales: Preliminary results from a new airway registry.

OBJECTIVES: Video laryngoscopy (VL) is increasingly used as an alternative to direct laryngoscopy (DL) to improve airway visualisation and endotracheal intubation (ETI) success. Intensive Care Paramedics in New South Wales Ambulance, Australia started using VL in 2020, and recorded success in a new advanced airway registry. We used this registry to compare VL to DL. METHODS: The present study was a retrospective analysis of out-of-hospital data for ETI by specialist paramedics using an airway registry. We calculated overall and first-pass success for VL versus DL, and compared success using a Χ2 test. RESULTS: The DL overall success was 61 out of 78 (78.2%) and VL was 233 out of 246 (94.7%); difference of 16.5% (P < 0.001). First-pass for DL was successful for 49 out of 78 (62.8%) and for VL in 195 out of 246 (79.3%); difference of 16.5% (P = 0.003). There were five (1.6%) patients where both VL and DL were used and in all instances, DL was used first. CONCLUSIONS: This analysis of a new airway registry used by specialist paramedics in New South Wales shows a substantial increase in overall and first-pass intubation success with the use of VL when compared to DL.