Spotlight on Research

The use of intraosseous needles in the management of paediatric cardiac arrest has increased rapidly with high rates of success reported in the literature. However, a study published in December 2019 reported much higher rates of misplacement in paediatric cadavers. This study applied post-mortem computed tomography on 38 paediatric cadavers where intraosseous needle (ION) access had been gained. Cadavers were divided into two categories: <1 year of age (infant) and >1 year of age (child). Misplacement of ION was only recorded if the signs of misplacement were clear so this may underestimate the total number.

On the 22 infant cadavers, 34 ION attempts had been made with malposition of at least one ION visible in 14 subjects (64%). Seven of those 14 (32%) had no correctly placed ION and 16 of the 34 ION devices (47%) were in malposition. In the 16 child cadavers, 23 ION attempts were found with at least one malpositioned in 50% of those cadavers. Three (19%) had no correctly placed ION. Most of these ION placements were undertaken in the out-of-hospital environment.

Although the study highlighted higher-than-anticipated malpositioning of ION, there were limitations. Further work is required to establish the accuracy of ION placement.

Morphine may not always appear to be the optimal drug for the management of acute pain in the elderly but sometimes there is little alternative. Recently, Motov et al compared the effectiveness of IV subdissociative-dose ketamine (SDK) (0.3 mg/kg) to IV morphine (0.1 mg/kg) administered as a short infusion to 60 older patients (>65 years) suffering from acute abdominal, flank, musculoskeletal or malignant pain. In this prospective, randomised, double-blind trial, the groups were evenly split to treatment arms. The primary outcome was a reduction in the numerical rating scale (NRS) for pain with secondary reporting of adverse events and the need for rescue analgesia.

Results showed a significantly greater reduction in the SDK group pain score at 15 minutes although, thereafter, the pain score in both groups continued to reduce at a comparable rate. Adverse effects were more commonly reported in the SDK group but no life-threatening events occurred in either group. Notably, significantly more of the morphine group required rescue analgesia at 120 minutes, although not at 30 or 60 minutes. The trial was limited by small numbers and lack of follow-up after 2 hours but further research could be helpful to establish a regimen for SDK administration to reduce adverse events while maintaining analgesic efficacy in line with morphine

Naloxone administration for opiate overdose has traditionally been via the intramuscular (IM) route; however, there could be benefits to the paramedic if the intranasal (IN) route is used. Previous prehospital research has shown the IN route to be inferior to the IM route but the studies were unblinded so could have introduced treatment bias into the results. This 2019 study was a double-blind, double-dummy randomised study completed in Australia. Subjects were randomised to one of two groups: (1) intranasal administration of naloxone hydrochloride 800 μg per 1 ml and intramuscular administration of placebo 1 ml or (2) intramuscular administration of naloxone hydrochloride 800 μg per 1 ml and intranasal administration of placebo 1 ml.

The primary outcome measure was the need for a rescue dose of intramuscular naloxone (800 μg) 10 minutes after the initial treatment with secondary outcomes including time to adequate respiratory rate (> 10 breaths/minute) and time to Glasgow Coma Scale score > 13.

Participants randomised to the IM route were less likely to require a rescue dose of naloxone, while those in the IN arm had higher risks in terms of recovery of respiratory rate and Glasgow Coma Scale score. This echoes previous research and shows that the optimum dose and concentration of IN naloxone remains to be established.

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