Strengths and Limitations
BLIND
A strength of this study was that it was conducted as a multicenter randomized clinical trial with a follow-up period of 6 months. Furthermore, the 3 participating neurosurgical departments each have defined population-based catchment areas, covering almost 60% of the Swedish population. All departments used the same surgical technique, and the benefit of body temperature irrigation was observed at all participating sites. Digitalized medical records used at the neurosurgical departments as well as the local hospitals within the catchment areas facilitated a complete follow-up of all but 5 study participants.A main limitation of this study was the inability to blind the treating surgeon to the irrigation fluid temperature. However, no significant difference was detected in the mean operating time or the amount of irrigation used between the 2 groups, indicating an unchanged surgical practice. Even though all departments use the same surgical technique, subtle differences cannot be ruled out. Another limitation is that of the 600 randomization allocations prepared, a total of 541 study participants had a complete follow-up. Unfortunately, 30 randomization envelopes were lost at 1 of the study sites and thus could not be used for randomization. The treatment allocations for these 30 envelopes were equally distributed between the 2 study groups. However, the obtained sample size still exceeded the number of study participants needed for a power of 80%. Finally, we did not register the reasons for nonenrolment, which was nevertheless in accordance with our study protocol.