水合氯醛镇静用于足月儿和早产儿的疗效和并发症的分析

背景足月和早产的婴幼儿在全身麻醉后存在呼吸暂停的风险。目前对于这类人群使用水合氯醛镇静后发生呼吸暂停的风险还不清楚。本研究观察水合氯醛用于未满1岁婴儿做磁共振成像（magneticresonanceimaging，MRI）检查的镇静效果，是否需要其他镇静药物，血氧饱和度降低的发生率以及是否需要供氧。本研究的目的在于观察这些因素与足月儿的实足年龄（chronologicalage）或早产儿（小于37周）的孕后年龄（postconceptionalage，PCA）及孕龄（gestationalage）的关系。方法这是一项回顾性队列研究。有1394例新生儿在进行MRI检查时使用水合氯醛镇静。排除条件包括气管内插管、气管切开或先天性心脏病患儿。通过患者MRI检查后24小时内的病史记录来发现独立风险因素和相关的结果变量。运用单因素和多因素分析来决定影响结果的危险因素。结果手术后血氧饱和度下降更有可能发生在住院的（P〈0．001），低体重（3．9±2．1kgVS6．6±3．0kg；P=0．001），有呼吸暂停吏（33．3％VS9．9％；P=0．001），高ASA评分（P=0．002）和实足年龄小（58．7±82．8天vs152±105．9天；P〈0．0001）的患儿。如果将早产儿单独统计，术后血氧饱和度下降的风险直接与实足年龄低（56．0±41．5天vs150．6±107．1天；P=0．012）和孕后年龄小（39．5±4．1周vs54．4±15．2周；P=0．005）有关，但与孕龄无关。早产儿术后心动过缓发生率高于足月儿（P=0．005）。手术后血氧饱和度下降没有一例发生在PCA大于48周的早产儿中。可能因为早产儿中手术后血氧饱和度下降的发生率低（262例中只有8例），我们无法确定其在足月儿和早产儿中发生率的差别。追加水合氯醛的剂量或辅助使用咪达唑仑并没有增加并发症的发生率。结论手术后血氧饱和度下降直接与足月儿的低实足年龄，早产儿的孕后年龄小有关。那些需要长时间供氧的足月新生儿是住院的患儿，并常伴有其他的疾病。

BACKGROUND： Term and preterm infants are at risk of developing apnea after receiving general anesthesia. The risk of apnea after sedation with chloral hydrate （CH） in this population is unknown. In this study, we aimed to describe the clinical course of infants younger than 1 year who received CH for magnetic resonance imaging （MRI）, with regard to the efficacy of CH sedation, the need for additional sedative drugs, and the incidence of oxyhemoglobin desaturation or need for oxygen supplementation. We aimed to determine the relationship between these factors to chronological age in term infants and gestational and postconceptional age （PCA） in preterm infants （37 weeks＇ gestation）. METHODS： This was a retrospective cohort study of 1394 infants undergoing MRI examination with CH sedation. Infants with an endotracheal tube, tracheostomy tube, or congenital heart disease were excluded. Patient charts were examined in detail to determine independent risk factors and dependent outcome variables up to 24 hours after MRI. Univariate and multivariate analyses were performed to determine risk factors for outcome variables. RESULTS： Postprocedure oxyhemoglobin desaturation was more likely in inpatients （P 〈 0. 001 ） and was associated with a lower body weight （3.9± 2.1 kg vs 6. 6± 3.0 kg; P 〈 0. 001 ）, history of apnea （33.3% vs 9.9%; P = 0. 001 ）, higher ASA physical status （P = 0. 002 ）, and younger chronological age （58.7 ± 82.8 days vs 152 ±105.9 days; P 〈 0. 0001 ）. When the preterm group was analyzed separately, the risk of postprocedure oxyhemoglobin desaturation was directly correlated with younger chronological age （56.0 ± 41.5 days vs 150. 6 ± 107.1 days; P = 0.012） and younger PCA （39.5 ± 4.1 weeks vs 54.4± 15.2 weeks; P = 0. 005）, but not gestational age. Preterm infants had more postprocedure bradycardia than term infants （P= 0.005）. Postprocedural oxyhemoglobin desaturation was not seen in preterm infants older than 48 weeks＇ PCA. Because of the relatively small percentage of cases （8 of 262 ） of postprocedural oxyhemoglobin desaturation in preterm infants, we were not able to definitively determine the difference in incidence between preterm and term infants. Additional doses of CH or supplementation with midazolam did not increase the incidence of complications. CONCLUSIONS： The occurrence of postprocedural oxyhemoglobin desaturation was directly correlated withyounger chronological age in term infants and younger PCA in preterm infants. Term infants who required extended oxygen supplementation were inpatients and had significant comorbidities.