The addition of ketamine to a morphine nurse- or patient-controlled analgesia infusion (PCA/NCA) increases analgesic efficacy in children with mucositis pain

Abstract

Aim: To assess the efficacy of adding ketamine to morphine nurse- or patient-controlled analgesia (NCA/PCA) infusions in treating mucositis pain in children.

Background: Mucositis pain can be very difficult to control in some patients despite the use of parenteral opioids. In our institution, we have started adding low-dose ketamine to the morphine NCA/PCA in these children in an effort to improve analgesic efficacy.

Methods/materials: The records of all children receiving a morphine/ketamine PCA or NCA for mucositis pain in our institution from 1999 to 2007 were reviewed. At the time of treatment, details of the analgesic management and consumption, pain scores and side effects were prospectively recorded and then entered on to an electronic database. Ketamine was added at a concentration of 20 or 40 microg x kg(-1) per ml with our standard morphine NCA/PCA infusions and protocols being used.

Results: In 28 patients, there was no difference between average morphine consumption in the 24 h pre and post the addition of ketamine (33.1 (+/-10.7) vs 35.2 (+/-14.3) microg x kg(-1) per hour, P = 0.45) but in those with recorded pain scores (n = 16), the median percentage of pain scores > or =4 was 48% (13-100%) preketamine versus 33% (0-82%) postketamine (P = 0.01). In all patients, there was no change in the rates of nausea and vomiting and pruritus pre and post the addition of ketamine and no other significant side effects were reported. No difference was seen between those who had 20 or 40 microg x kg(-1) per ml of ketamine added.

Conclusion: The addition of ketamine to a morphine NCA/PCA improves analgesic efficacy in children with mucositis pain with no increase in the incidence of side effects.