The effect of combined treatment with morphine sulphate and low-dose ketamine in a prehospital setting

Abstract

BackgroundPain is a common condition among prehospital patients. The present study is designed to determine whether adding low-dose ketamine as additional analgesia improves the pain/nausea scores and hemodynamic parameters compared to morphine sulphate alone among patients with bone fractures.MethodsProspective, prehospital clinical cohort study. Twenty-seven patients were included with acute pain. Eleven patients received morphine sulphate 0.2 mg/kg (M-group) and 16 patients received morphine sulphate 0.1 mg/kg combined with 0.2 mg/kg ketamine (MK-group). Scores for pain, nausea, sedation (AVPU) and the haemodynamic parameters (systolic blood pressures (BP), heart rate (HR) and peripheral oxygen saturation (SpO2) were recorded at rescue scene before the start of analgesia and subsequently to admission at hospital.ResultsMean treatment time 46 ± 17 minutes in the M-group and 56 ± 11 minutes in the MK-group, respectively (ns). Mean doses of morphine sulphate in the M-group were 13.5 ± 3.2 mg versus 7.0 ± 1.5 mg in the MK-group. The mean additional doses of ketamine in the MK-group were 27.9 ± 11.4 mg. There were significantly differences between the M- and the MK-group according to NRS scores for pain (5.4 ± 1.9 versus 3.1 ± 1.4) and BP (134 ± 21 mmHg versus 167 ± 32 mmHg) at admission at hospital, respectively (P < 0.05). All patients were Alert or respond to Voice and the results were similar between the groups. One patient versus 4 patients reported nausea in the M- and MK-group, respectively, and 3 patients vomited in the Mk-group (ns).ConclusionWe conclude that morphine sulphate with addition of small doses of ketamine provide adequate pain relief in patients with bone fractures, with an increase in systolic blood pressure, but without significant side effects.

The Effects of Low-Dose Ketamine on Acute Pain in an Emergency Setting: A Systematic Review and Meta-Analysis

“…However, 1,014 of these studies were excluded (Fig 1). Among the eligible 20 studies, 3 systematic reviews, 9 non-RCTs [19–27] and 2 RCTs [28,29] were excluded: a case series and a letter [19,26], three retrospective studies [23–25], studies that used treatments other than intravenous infusion [20,21,23], a prospective study in which both ketamine and hydromorphine were simultaneously used without a control group [22], and another study that was a prospective cohort study with multiple biases, such as selection, performance, detection, and reporting bias [27]. None of the above excluded studies were RCTs.…”

Low‐dose Ketamine Improves Pain Relief in Patients Receiving Intravenous Opioids for Acute Pain in the Emergency Department: Results of a Randomized, Double‐blind, Clinical Trial

“…Several small observational or open-label studies have demonstrated either morphine-sparing effects or reductions in pain severity when low-dose ketamine is employed for pain in the prehospital or ED setting. [8][9][10][11][12] However, lack of randomized controlled clinical trials examining the effectiveness of low-dose ketamine in the ED may partly explain why it has not been incorporated into regular clinical practice. In addition, guidance is needed regarding the optimum dose for ketamine as an adjunct analgesic; studied doses have ranged from 0.05 to 1 mg/kg, and various methods and routes of administration have been employed (single bolus, repeat dosing, or continuous infusion; IV, intramuscular, intranasal, or intrathecal).…”

Evaluation of analgesic effects of ketamine through sub-dissociative dosing in the ED

“…Galinski et al [16] treated patients experiencing severe pain in mobile intensive care units in a double-blind RCT and found a statistically significant (P = 0.002) increase in neuropsychological adverse effects (36% vs 3%) with administration of 0.2 mg/kg intravenous ketamine compared to morphine including hallucinations, dizziness, diplopia, and dysphoria. Gurnani et al [17] showed less overall nausea, whereas Johansson et al [21] showed more overall nausea in the morphine only group vs the ketamine plus morphine group. In an RCT by Weinbroum [10], intravenous ketamine (0.25 mg/kg, n = 131) plus morphine (0.015 mg/kg) vs morphine alone (0.030 mg/kg, n = 114) resulted in less postoperative nausea and ☆ Explanation of lead authors credentials.We believe Heidi Riha, BS, PharmD Candidate 2015, has the qualifications and contributions to the paper to establish herself as the lead author.…”

“…Most of the studies evaluating ketamine as an analgesic in the emergency setting used it as adjunctive therapy in addition to an opioid [7,16,17,[20][21][22][23][24][25][26]. A few observational studies and one randomized controlled trial (RCT) evaluated the use of low-dose ketamine alone [19,[27][28][29].…”

“…In a large retrospective study evaluating low-dose ketamine (0.1 to 0.3 mg/kg, intravenously or intramuscularly) administered in the ED for analgesia (n = 530), only 6% of patients developed a mild adverse event, which rarely altered the patient's clinical course [30]. Low-dose ketamine use for analgesia in the emergency setting has generally been shown to be well tolerated [7,17,19,21,22,[24][25][26][27][28][29][30][31]. The differences in adverse effects associated with ketamine administration may be due to interstudy variability in the study populations, the dosing strategies used, or random error due to the small study populations.…”