Kara, I., Apiliogullari, S., Oc, B., Celik, J.B., Duman, A., Celik, C., & Dogan, N.U. (2012). The effects of intrathecal morphine on patient-controlled analgesia, morphine consumption, postoperative pain and satisfaction scores in patients undergoing gynaecological oncological surgery. Journal of International Medical Research, 40, 666–672.
To compare the impact of intrathecal morphine (ITM) plus patient-controlled analgesia (PCA) versus PCA alone on morphine consumption, pain relief, and patient satisfaction after gynecologic-oncologic surgery (GOS)
Patients were randomized to an ITM plus PCA group or a PCA-only control group. Study patients received 0.3 mg ITM at the L3-L4 or L4-L4 vertebral level, and control patients received a needle puncture only. The same anesthesiologist performed all procedures. All patients received an initial morphine bolus of 0.05 mg/kg if pain was > 60 (0–100) on a Visual Analog Scale in the postanesthesia care unit. The PCA was reprogrammed for all patients to deliver a 1.5 mg bolus with a seven-minute lockout after patients were discharged from the postanesthesia care unit. Measurements were taken at 30 minutes and at one, three, six, 12, 24, and 48 hours.
Prospective, randomized, double-blinded study
Primary Measures
Pain scores were assessed using a 100 mm Visual Analog Scale (VAS, 0 mm = no pain, and 100 mm = worst pain imaginable). Patient satisfaction was measured using a 100 mm VAS (0 = very unsatisfied, and 100 = very satisfied), and cumulative PCA morphine consumption (mg) was calculated.
Secondary Measures
Patients were directly asked if they experienced nausea, vomiting, or pruritus. Rescue medication was administered for nausea and vomiting. The number of patients who verbally reported secondary measures and who received rescue medications were recorded.
Sedation was assessed using a five-point scoring scale (0 = fully awake, 1 = drowsy, closed eyes, 2 = asleep but easily aroused with light tactile stimulation or simple verbal command, 3 = asleep and aroused only by strong physical stimulation, and 4 = could not be aroused. Fatigue also was assessed on a four-point scale (0 = none, and 4 = severe). Respiratory depression was defined by a rate of less than 10 breaths per minute and was reversed by administering 0.1 mg of IV naloxone every five minutes until adequate respiration was restored.
Primary Outcomes
Patients in the ITM plus PCA group had a lower consumption of morphine (p < 0.0001 at all time points). There was no statistic difference in pain or patient satisfaction scores.
Secondary Outcomes
There was no statistic difference in sedation, nausea, pruritus, or fatigue between the two groups.
ITM plus PCA significantly reduced morphine consumption compared to PCA alone in the first 48 hours after GOS. The intervention, however, did not decrease pain scores or improve patient satisfaction. Both the intervention and the control group reported similar levels of the secondary side effects measured in this study.
ITM plus PCA may be a viable option to decrease overall morphine consumption for patients in whom this is a desired outcome as it did not increase adverse side effects. However, the addition of ITM did not improve postoperative pain scores or overall patient satisfaction in patients receiving GOS.