Article Review Paper on Adding Ketamine to Morphine for Intravenous Patient-controlled Analgesia for Acute Postoperative Pain

Article Review

            Controlling analgesia in patients using intravenous opioids is a deep-rooted technique in nursing. This helps in controlling pain among patients after undergoing major surgeries. This method of pain control is better than the intravenous bolus doses (Tveita, 2008); patients are more satisfied and collaborate better with the caregivers. The adverse effects of the opioid include drowsiness, vomiting, and nausea (Carstenseni & Møller, 2010). The use of opioids can further result in acute intolerance; these effects facilitate better management of pain. It also impairs haemodynamic and respiratory depression. These effects elicit the need to reduce the side effects of opiods in order to manage the pain more effectively.

 The use of Ketamine was found to be essential in the management of the side effects of opiods. Ketamine is not a competitive NMDA (N-methyl-D-aspartate) antagonist. By applying Ketamine at specific NMDA barriers and modulating the main sensitization, it was found to offer an anti-hyperalgesic effect. This study was carried out on animals and the results contradicted those realized among human beings, as the results in the latter were mixed (Carstenseni & Møller, 2010). This was in relation to effectiveness and tolerability. Therefore, the effect of Ketamine was questionable among human beings. In further research, randomized placebo controlled tests were used; the main purpose was to evaluate the efficacy and safety of the intravenous opiod with Ketamine for the management of the post-operative pain (Carstenseni & Møller, 2010).

It was realized that Ketamine had specific modes of action. This, combined with the weakness in methodology, explained the mixed results in the study. Things to be considered when using this mode of pain management include the dose of Ketamine, the ratio  of the Ketamine and Morphine, the starting time of the PCA device, type of surgery, and the method of measuring pain. There is need to ensure that the ration of the morphine to Ketamine is 1:1 for patients who have undergone hip surgery and lumbar spine surgery. The stepwise optimization models need to be used in these cases (Carstenseni & Møller, 2010).


Carstenseni, M. & Møller, A. M. (2010). Adding Ketamine to Morphine for Intravenous Patient-controlled Analgesia for Acute Postoperative Pain: A Qualitative Review of Randomized Trials: British Journal of Anaesthesia. Vol. 104(4): 410-406

Tveita, T., Thoner, J., Klepstad, P., Dale, O., Jystad, A. & Borchgrevink, P. C. (2008). A Controlled Comparison between Single Doses of Intravenous and Intramuscular Morphine with respect to Analgesic Effects and Patient Safety: Acta Anaesthesiol Scand.. Vol. 52: Pages 920–925