Is intravenously administered, subdissociative-dose KETAmine non-inferior to MORPHine for prehospital analgesia (the KETAMORPH study): study protocol for a randomized controlled trial

Randomised controlled trial of analgesia for the management of acute severe pain from traumatic injury: study protocol for the paramedic analgesia comparing ketamine and morphine in trauma (PACKMaN)

BACKGROUND

Prehospital analgesia is often required after traumatic injury, currently morphine is the strongest parenteral analgesia routinely available for use by paramedics in the United Kingdom (UK) when treating patients with severe pain. This protocol describes a multi-centre, randomised, double blinded trial comparing the clinical and cost-effectiveness of ketamine and morphine for severe pain following acute traumatic injury.

METHODS

A two arm pragmatic, phase III trial working with two large NHS ambulance services, with an internal pilot. Participants will be randomised in equal numbers to either (1) morphine or (2) ketamine by IV/IO injection. We aim to recruit 446 participants over the age of 16 years old, with a self-reported pain score of 7 or above out of 10. Randomised participants will receive a maximum of 20 mg of morphine, or a maximum of 30 mg of ketamine, to manage their pain. The primary outcome will be the sum of pain intensity difference. Secondary outcomes measure the effectiveness of pain relief and overall patient experience from randomisation to arrival at hospital as well as monitoring the adverse events, resource use and cost-effectiveness outcomes.

DISCUSSION

The PACKMAN study is the first UK clinical trial addressing the clinical and cost-effectiveness of ketamine and morphine in treating acute severe pain from traumatic injury treated by NHS paramedics. The findings will inform future clinical practice and provide insights into the effectiveness of ketamine as a prehospital analgesia.

TRIAL REGISTRATION

ISRCTN, ISRCTN14124474. Registered 22 October 2020, https://www.isrctn.com/ISRCTN14124474.

Comparison of the Analgesic Effects of Low-Dose Ketamine Versus Fentanyl in Patients With Long Bone Fractures in the Emergency Department: A Prospective Observational Study

Aim and background In most emergency departments (ED), opioids are the primary analgesic agents for trauma patients. However, safe alternative drugs are required because of possible adverse effects. Ketamine, an anesthetic agent, provides satisfactory analgesia at low doses and is an alternative drug that has begun to be used in numerous areas with fewer side effects. This study aimed to compare low-dose ketamine and fentanyl infusions in terms of their pain-relieving effects and observed adverse effects in patients presenting to the ED with isolated long bone fractures. Materials and methods This single-center observational study was conducted in the ED of the Marmara University Pendik Training and Research Hospital between August 2018 and December 2019. Patients diagnosed with isolated long bone fractures who were administered low-dose ketamine or fentanyl rapid infusions for pain relief were included in the study. Patient pain scores were evaluated using the visual analog scale (VAS) with a standard horizontal 10-centimeter line. The primary outcome of the study was to compare the changes in pain at 30 and 60 min after medication administration for each group. Results A total of 100 patients were included in the study. Ketamine infusion was administered to 48% (n=48) of the patients as a pain reliever. After 60 min of observation, pain was significantly reduced in both study groups. However, the pain scores at baseline (p=0.319), 30 min (p=0.631), and 60 min (p=0.347) after treatment were similar in both groups. In terms of the observed adverse effects, dizziness was more common in the ketamine group (p=0.010). Conclusion The results of this study showed that low-dose ketamine infusion (0.3 mg/kg/h) had a similar effect to fentanyl infusion (1 mcg/kg/h) as a pain reliever in patients with isolated long bone fractures in the ED.

Comparison of three regimens with inhalational methoxyflurane versus intranasal fentanyl versus intravenous morphine in pre-hospital acute pain management: study protocol for a randomized controlled trial (PreMeFen)

BACKGROUND

Pre-hospital pain management has traditionally been performed with intravenous (IV) morphine, but oligoanalgesia remain a recognized problem. Pain reduction is essential for patient satisfaction and is regarded as a measure of successful treatment. We aim to establish whether non-invasive methods such as inhalation of methoxyflurane is non-inferior to intranasal fentanyl or non-inferior to the well-known IV morphine in the pre-hospital treatment of acute pain.

METHOD/DESIGN

The PreMeFen study is a phase three, three-armed, randomized, controlled, non-inferiority trial to compare three regimens of analgesics: inhalation of methoxyflurane and intranasal (IN) fentanyl versus IV morphine. It is an open-label trial with a 1:1:1 randomization to the three treatment groups. The primary endpoint is the change in pain numeric rating scale (NRS) (0-10) from baseline to 10 min after start of investigational medicinal product administration (IMP). The non-inferiority margin was set to 1.3, and a sample size of 270 patients per protocol (90 in each treatment arm) will detect this difference with 90% power.

DISCUSSION

We chose a study design with comparison of analgesic regimens rather than fixed doses because of the substantial differences in drug characteristics and for the results to be relevant to inform policymakers in the pre-hospital setting. We recognize that easier administration of analgesics will lead to better pain management for many patients if the regimens are as good as the existing, and hence, we chose a non-inferiority design. The primary endpoint, the change in pain (NRS) after 10 min, is set to address the immediate need of pain reduction for patients with acute prehospital pain. On a later stage, more analgesic methods are often available. PreMeFen is a non-inferiority randomized controlled trial comparing three analgesic regimens aiming to establish whether inhalation of methoxyflurane or intranasal fentanyl is as good as IV morphine for fast reduction of acute pain in the prehospital setting.

Interactions between Ketamine and Magnesium for the Treatment of Pain: Current State of the Art

BACKGROUND

Over the past three decades, NMDA-receptor antagonists have been shown to be efficient drugs for treating pain, particularly pain resistant to conventional analgesics. Emphasis will be on the old-new drugs, ketamine and magnesium, and their combination as a novel approach for treating chronic pain.

METHODS

The MEDLINE database was searched via PubMed for articles that were published up to March 1, 2020, with the keywords 'ketamine', 'magnesium', and 'pain' (in the title/abstract).

RESULTS

Studies in animals, as well as humans, have shown that interactions of ketamine and magnesium can be additive, antagonistic, and synergistic. These discrepancies might be due to differences in magnesium and ketamine dosage, administration times, and the chronological order of drug administration. Different kinds of pain can also be the source of divergent results.

CONCLUSION

This review explains why studies performed with a combination of ketamine and magnesium have given inconsistent results. Because of the lack of efficacy of drugs available for pain, ketamine and magnesium in combination provide a novel therapeutic approach that needs to be standardized with a suitable dosing regimen, including the chronological order of drug administration.

Ketamine for pain control of snake envenomation in Guinea: A case series

Snakebite envenomation is a global health crisis and is classified as a Category A neglected tropical disease by the World Health Organization (WHO). Snakebite envenomations account for a significant amount of morbidity and morbidity in tropical and subtropical regions. Recently, publications have illustrated the potential for snake envenomations causing post-traumatic stress disorder (PTSD) in a significant number of patients. Ketamine is on the WHO's list of essential medications and is used for a variety of pharmacologic applications including anesthesia and acute pain management. To date it has not been assessed for pain control in snakebite envenomations. Twelve patients who presented with severe pain secondary to Bitis, Causus, and Atractaspis envenomations were treated with low-dose intravenous ketamine. The patients included 7 males and 5 females with a median age of 37.5 (range 14-64) and a median presentation time of 5.75 h (range 5 min-96 h) after the initial bite occurred. Ten envenomations were presumed to have been caused by Bitis species resulting in extensive swelling and blistering of the affected extremities. One envenomation was presumedC. maculatus causing local swelling and pain. One envenomation was a presumed Atractaspis species causing significant local pain with minimal swelling. All patients expressed having significant pain but could not express the degree of their pain using an analogue pain scale. An initial median dose of 5 mg of ketamine (range 2.5-15 mg) was administered intravenously for pain control. Every patient expressed decreased pain and felt more comfortable within 1 min after administration of ketamine. Nine of the twelve patients only required a single dose. There were no adverse side effects. Ketamine appears to be an effective means of pain control for those suffering from painful envenomations. With minimal risk of significant side effects at acute pain management doses and the average cost per effective dose averaging between US$0.03-0.06, this may provide a cheap, safe, and effective solution for Sub-saharan Africa and other resource-limited settings. Controlled studies need to be done to critically assess our observations.

The effects of a morphine shortage on emergency department pain control

OBJECTIVE

In 2018, due to a national morphine shortage, our two study emergency departments (EDs) were unable to administer intravenous (IV) morphine for over six months. We evaluated the effects of this shortage on analgesia and patient disposition.

METHODS

This was a retrospective study in two academic EDs. Our control period (with morphine) was 4/1/17-6/30/17 and our study period (without morphine) was 4/1/18-6/30/18. We included all adult patients with a chief complaint of pain, initial pain score ≥4, and ≥2 recorded pain scores. The primary outcome was delta pain score. Secondary outcomes included final pain score, proportion of ED visits with opioids vs. non-opioids administered, and ED disposition.

RESULTS

We identified 6296 patients during our control period and 5816 during our study period. There was no significant difference in mean final pain score (study 4.45, control 4.44, p = 0.802), delta pain score (study -3.30, control -3.32, p = 0.556), nor admission rates (study 18.8%, control 17.8%, p = 0.131). We saw a decrease in opioid use (study 47.4%, control 60.0%, p < 0.01) and an increased use of non-opioid analgesics (study 27.3%, control 18.44%, p < 0.01).

CONCLUSIONS

Removing IV morphine in the ED, without a compensatory rise in alternative opioids, does not appear to significantly impact analgesia or disposition. These data favor a more limited opioid use strategy in the ED.