Efficacy and Safety of Morphine and Low Dose Ketamine for Pain Control of Patients with Long Bone Fractures: A Randomized, Double-Blind, Clinical Trial

Abstract

Objective:To compare the effects of intravenous morphine and a low dose of ketamine on pain intensity of patients with traumatic fractures of the long bones. Methods: This randomized, controlled, double-blinded, clinical trial was conducted in the adult emergency department (ED) of Emam Khomeini hospital, a tertiary general hospital affiliated with Mazandaran University of Medical Sciences, in Northern Iran, during a 6-month period. Patients were randomly assigned to receive intravenous morphine (0.1 mg/kg) or low dose ketamine (0.5 mg/kg) for control of the pain in the emergency room. The pain intensity was checked by a nurse using the visual analogue scale (VAS) at 30, 60, 90, 120, 180 and 240, minutes after the intervention. Results: Overall we included a total number of 156 patients with mean age of 35.87±3.38 years. There were 111 (71.2%) men and 4 (28.8%) women among the patients. Patients were randomly assigned to receive intravenous morphine (n=78) or low dose ketamine (n=78). The pain intensity decreased significantly in both study groups after 240 minutes of intervention. However, there was no significant difference between the two study groups regarding the pain intensity at 30 (p=0.378), 60 (p=0.927), 90 (p=0.434), 120 (p=0.557), 180 (p=0.991) and 240 (p=0.829) minutes. The side effects were comparable while low dose ketamine was associated with higher need for rescue analgesic (p=0.036). Conclusion:The results of the current study demonstrates that the intravenous low dose ketamine leads to successful pain control in patients with long bone fractures and the effects are comparable with intravenous morphine.

Low‐dose Ketamine For Acute Pain Control in the Emergency Department: A Systematic Review and Meta‐analysis

“… 12–14,20,21,23 The pooled estimate showed no significant difference in mean pain scores between LDK and morphine within 15 minutes (MD = −0.15, 95% CI = −0.68 to 0.38). Six studies reported a pain score between 15 and 30 minutes 13,14,20–23 . The pooled estimate showed no significant difference in mean pain scores between groups (MD = −0.03, 95% CI = −0.37 to 0.32).…”

“…Three studies with a total of 306 patients (153 in the LDK group and 153 in the morphine group) reported on the use of rescue medication (Figure 4). 13,20,22 The pooled estimate showed no significant difference in need for rescue medication between LDK and morphine (14.4% vs. 11.1%; RR = 1.26; 95% CI: 0.50 to 3.16, very low certainty). Seven of the included studies with a total of 1,065 patients (535 in the LDK group and 530 in the morphine group) reported on nausea 13,14,20‐24 .…”

“…A summary of the included trials is shown in Table 1. All studies were published between 2014 and 2019 12–14,20–24 . One study was reported as an abstract 24 .…”

“…All studies used morphine boluses of 0.1 mg/kg intravenously. Four studies examined patients with abdominal, flank, low back, or extremity pain; 13,14,20,21 two studies examined patients with long‐bone fractures; 12,22 one study examined trauma patients with musculoskeletal pain; 23 and one study examined those with a sickle cell pain crisis 24 . All studies were conducted in the ED, with no prehospital studies included.…”

Is Low-Dose Ketamine an Effective Alternative to Opioids for Acute Pain?

“…Results in regard to frequency of adverse events and efficacy at later points were mixed. [8][9][10] This study suggests that low-dose intravenous ketamine provides analgesia comparable to that of intravenous morphine at 0.1 mg/kg. 11 However, it is unclear how ketamine compares with titrated opioids or whether it can be effectively redosed or titrated.…”