The effect of low-dose ketamine via patient-controlled analgesic pump on morphine consumption in the postoperative period in thoracotomies: a systematic review protocol.

REVIEW QUESTION/OBJECTIVE: The objective of this systematic review is to determine if adding low-dose ketamine to a morphine patient-controlled analgesic pump will have an impact on the total consumption of morphine during the first 72 hours postoperative in patients over the age of 15 undergoing surgery involving thoracotomy. In addition, secondary outcomes assessing the impact on pain, nausea and vomiting will be evaluated for any alteration with ketamine co-administration.