Background and Aims:  Morphine is pain relieving drug that can have a 20-24 hours effect when used intrathecally1, however the use of morphine intrathecally is not without risks. The risks include nausea, vomiting, pruritus and most feared respiratory depression. Effects and side effects are all dose dependent, thus a reliable concentration of morphine is of vital importance. Second, the injectate has to be sterile to prevent meningitis. The goal of this study is to measure the accuracy of morphine concentrations and sterility in syringes prepared by the pharmacy department and anaesthesia providers.

Methods:  Twenty-five anaesthesia providers prepared syringes of 5ml morphine 60mcg/ml + 2 mg/ml bupivacaine. Each anaesthesia provider prepared two syringes per three methods via step-by-step-instruction. They also had to extract 2 syringes of 5ml from the ampoules prepared by the pharmacy department. Morphine concentrations were measured by HPLC and cultures were taken from the duplicate syringe.
Results: The concentrations of the ampoules by the pharmacy department were accurate and precise (median of 59mcg/ml with a 95%-CI of 59-59mcg/ml). The first method yielded 3 clinically unacceptable high concentrations (60 [59-110] mcg/ml) and the other two methods were relatively precise although inaccurate (76 [72-80] mcg/ml and 69 [66-71] mcg/ml). All four groups had 1 contaminated sample.
Conclusions: To provide safe and accurate low concentrations of morphine intrathecally one should use pharmacy prepared solutions. Care should be given to aseptic measures of intrathecal solutions.     

 1. Intrathecal Morphine for Laparoscopic Segmental Colonic Resection as Part of an Enhanced Recovery Protocol 
 Reg Anesth Pain Med. 2018 Feb; 43(2): 166–173

MORPHINE CONCENTRATION AND CONTAMINATION AFTER DILUTION AND EXTRACTION FROM AMPOULES INTO SYRINGES (MOCCA TRIAL)