[Meta-analysis of the effects of dexmedetomidine combined with ketamine during dressing changes in burn patients].

Objective: To systematically evaluate the safety and efficacy of dexmedetomidine combined with ketamine during dressing changes in burn patients using meta-analysis. Methods: Foreign language databases including PubMed, Cochrane Central, Embase, and Web of Science were searched with the terms of " burns, dexmedetomidine, ketamine, and dressing" , and Chinese databases including Chinese Journal Full-Text Database, Wanfang Data, and China Academic Journal Network Publishing Database were searched with the terms in Chinese version of ",,,,," to retrieve the publicly published randomized controlled trials on the application of dexmedetomidine combined with ketamine for sedation and analgesia during dressing changes in burn patients from the establishment of each database to March 2019. The outcome indexes included systolic blood pressure at 5 minutes after administration, arousal restlessness score, ketamine dosage, dressing change time, body movement/recovery time, pain score, Ramsay sedation scores at 10 minutes after the start of dressing change and 1 hour after dressing change, physician satisfaction score, neuropsychological symptoms, nausea and vomiting times, nausea and vomiting score. RevMan 5.3 and Stata 14.0 statistical software were used to conduct a meta-analysis of eligible studies. Results: A total of 396 burn patients were included in 7 articles, including 198 patients in dexmedetomidine+ ketamine group who received dexmedetomidine and ketamine for sedation and analgesia, and 198 patients in ketamine alone group who received ketamine alone for sedation and analgesia. The bias risks of the seven studies included were uncertain. Compared with those of ketamine alone group, the systolic blood pressure at 5 minutes after administration, arousal restlessness score, nausea and vomiting score of patients in dexmedetomidine+ ketamine group were significantly decreased, with standardized mean differences of -13.89, -0.84, and -0.99 (95% confidence interval=-20.89--6.89, -1.17--0.52, -1.31--0.68, P<0.01), the Ramsay sedation score at 10 minutes after the start of dressing change and that at 1 hour after dressing change were significantly increased, with standardized mean differences of 1.53 and 0.72 (95% confidence interval=1.05-2.02, 0.13-1.31, P<0.05 or P<0.01), and the number of neuropsychological symptom and number of nausea and vomiting were significantly reduced, with relative risks of 0.20 and 0.16 (95% confidence interval=0.07-0.58, 0.05-0.58, P<0.01). The patients in the two groups were similar in ketamine dosage, dressing change time, body movement/recovery time, pain score, and physician satisfaction score. There was no publication bias in dressing change time or ketamine dosage (P>0.05), while the other indexes might have publication bias (P<0.05). Conclusions: Compared with ketamine alone, combination of dexmedetomidine and ketamine during dressing changes in burn patients can reduce the occurrence of restlessness, nausea and vomiting, neuropsychological symptoms, and other complications, better stabilize blood pressure, and enhance sedation effect.