[Efficacy and safety of intranasal dexmedetomidine premedication for children undergoing CT or magnetic resonance imaging: a systematic review and meta-analysis].

Objective: To review the efficacy and safety in children receiving intranasal dexmedetomidine premedication before CT or magnetic resonance imaging (MRI). Methods: A literature search (search terms included "dexmedetomidine" "intranasal drug administration" "children" "CT" and "MRI") was conducted using Embase, PubMed, the Cochrane Library, ClinicalTrials.gov, CNKI, Wanfang, VIP database and Chinese Biomedical Literature Database (searched from inception to March 18, 2019). Randomized controlled trials of children receiving intranasal dexmedetomidine versus chloral hydrate, ketamine or midazolam premedication before CT or MRI were included. The Cochrane Reviewers' Handbook 5.1.0 was used to evaluate the quality of the enrolled studies. The primary outcomes were sedation success rate and sedation induction time. The secondary outcomes included respiratory depression, heart rate, systolic blood pressure and blood oxygen saturation. Statistical analyses were performed using the Review Manager 5.3 software. Results: A total of 1 167 participants in 9 randomized controlled trials were included. The results of meta-analysis showed that intranasal dexmedetomidine premedication provided higher sedation success rate than oral chloral hydrate (relative risk (RR) =1.13, 95% confidence interval (CI) 1.02 to 1.26, P=0.020). There was no significant difference between intranasal dexmedetomidine and midazolam. In addition, the sedation induction time of intranasal dexmedetomidine group was significantly shorter than that in the oral chloral hydrate group (weighted mean difference -1.49, 95% CI -2.87 to -0.11; P=0.030), but showed no significant difference as compared with that of intranasal ketamine or midazolam. The patients treated with intranasal dexmedetomidine also showed significantly lower heart rate (RR=4.78, 95%CI 1.85-12.35, P=0.001) and less respiratory depression (RR=0.28, 95%CI 0.09-0.87, P=0.030). There were no intergroup differences in systolic blood pressure and blood oxygen saturation. Conclusions: Intranasal dexmedetomidine provided more effective sedation and higher safety in children undergoing CT or MRI. As this meta-analysis is limited by the small sample size, further high-quality randomized controlled trials are needed.目的： 系统评价右美托咪定滴鼻用于患儿CT或磁共振成像（MRI）检查的镇静效果及安全性。 方法： 计算机检索EMbase、PubMed、循证医学图书馆、全球临床试验数据库、中国知网、万方数据库、维普数据库和中国生物医学文献数据库，英文检索词为"dexmedetomidine""intranasal drug administration""children""CT""MRI"，中文检索词为"右美托咪定""滴鼻""患儿""CT""MRI"，检索时限均为建库至2019年3月18日，纳入并对比右美托咪定滴鼻与对照组（水合氯醛、氯胺酮或咪达唑仑）用于患儿CT或MRI检查的随机对照研究(RCT)，采用Cochrane系统评价手册5.1.0进行质量评价，以镇静成功率和镇静诱导时间为主要结局指标，呼吸、心率、血压、血氧饱和度的不良反应发生率为次要结局指标，运用Rev Man 5.3统计软件进行Meta分析。 结果： 纳入9项RCT，总样本量1 167例患儿。Meta分析结果显示，右美托咪定滴鼻比口服水合氯醛镇静成功率更高[相对危险度（RR）=1.13,95%置信区间（CI）1.02~1.26,P=0.020]，与咪达唑仑差异无统计学意义；右美托咪定滴鼻比口服水合氯醛所需镇静诱导时间更短(加权均数差-1.49,95%CI -2.87~-0.11,P=0.030)，与氯胺酮滴鼻和咪达唑仑差异无统计学意义；与对照组相比，右美托咪定滴鼻显著降低患儿的心率（RR=4.78,95%CI 1.85~12.35，P=0.001）；呼吸抑制发生率更低（RR=0.28,95%CI 0.09~0.87，P=0.030）；右美托咪定滴鼻与对照组血压和血氧饱和度差异无统计学意义。 结论： 右美托咪定滴鼻用于患儿CT或MRI检查的镇静成功率更高，且安全性好，但结论仍需高质量的随机对照试验来证实。.