Objective: To evaluate the influence of preoperative fasting duration on blood volume status of pediatric patients during induction based on ultrasonic technique. Methods: One hundred and ten pediatric patients, scheduled for elective operation in the Second Affiliated Hospital & Yuying Children's Hospital, were recruited during January and October in 2018. After sedation by inhalation of sevoflurane, the maximum (expiratory) and minimum (inspiratory) diameter of inferior vena cava (IVC(max), IVC(min)) and aorta velocity-time integral (VTI) in apical five-chamber cardiac view were measured with an ultrasound machine. Respiratory variabilities of these parameters were further calculated. Furthermore, passive leg raising (PLR) test was performed and above measurements/calculations were repeated. The correlation between the duration of fasting and IVC respiratory variations index (IVC(RVI)) or aortic VTI variability (ΔVTI) was then analyzed. Results: Before PLR, IVC(max), IVC(min) and IVC(RVI) were (0.78±0.19), (0.43±0.15) cm and 0.45±0.12, respectively. After PLR, IVC(max) and IVC(min) increased to (0.94±0.20), (0.55±0.18) cm, while IVC(RVI) decreased to 0.42±0.13, the differences were statistically significant (t=15.66, 10.85, 3.14, all P<0.05). However, IVC(max), IVC(min) and IVC(RVI) were not significantly correlated with the duration of fasting analyzed by linear regression (before PLR: r=0.052, 0.163, 0.171; after PLR, r=0.062, 0.169, 0.165, all P>0.05). Before PLR, expiratory aortic VTI (VTI(max)), inspiratory aortic VTI (VTI(min)) and ΔVTI were 21±5, 17±4 and 17±8, respectively. After PLR, the VTI(max) and VTI(min) significantly increased to 23±5 and 19±4 (t=13.60, 10.43, all P<0.05), but ΔVTI was not changed significantly, which was 17±8(t=0.34, P>0.05). Linear regression analysis showed that VTI(max), VTI(min) and ΔVTI were not significantly correlated with the duration of fasting (before PLR: r=0.111, 0.100, 0.047; after PLR: r=0.003, 0.033, 0.073, all P>0.05). Further multiple linear regression analysis indicated that, age and body weight were independent factors influencing IVC(RVI) and ΔVTI before and after PLR (IVC(RVI): β=-0.441, 0.515, -0.451, 0.507; ΔVTI: β=-0.442, 0.545, -2.422, 2.850; all P<0.05). However, the duration of fasting was not correlated with IVC(RVI) and ΔVTI after adjusting the age and weight (IVC(RVI): β=0.177, 0.160; ΔVTI: β=0.037, 0.054; all P>0.05). Conclusion: Age and weight, but not preoperative fasting duration, are correlated with respiratory variabilities of inferior vena cava diameter and aortic VTI in pediatric patients.
目的： 采用超声技术评估禁饮禁食时间与患儿诱导期血容量状态的关系。 方法： 选择2018年1至10月期间在温州医科大学附属第二医院实施择期手术患儿110例。七氟烷诱导镇静后，分别测量下腔静脉（IVC）直径最大值（呼气相，IVC(max)）、最小值（吸气相，IVC(min)）和心尖五腔心切面主动脉血流速度时间积分（VTI），并计算上述各个参数随呼吸变化的变异度；再行被动抬腿试验（PLR）重复测量和计算上述指标。对禁饮禁食时间长短与IVC变异度（IVC(RVI)）、主动脉VTI变异度（ΔVTI）行多元线性回归分析。 结果： PLR前，IVC(max)、IVC(min)和IVC(RVI)分别为（0.78±0.19）、（0.43±0.15）cm和0.45±0.12；PLR后，IVC(max)和IVC(min)分别增加至（0.94±0.20）、（0.55±0.18）cm，而IVC(RVI)减小为0.42±0.13，差异均有统计学意义（t=15.66、10.85、3.14，均P<0.05）。IVC(max)、IVC(min)、IVC(RVI)均与禁饮禁食时长无相关性（PLR前：r=0.052、0.163、0.171；PLR后：r=0.062、0.169、0.165，均P>0.05）。PLR前，呼气相VTI（VTI(max)）、吸气相VTI（VTI(min)）和ΔVTI分别为21±5、17±4和17±8；PLR后，VTI(max)和VTI(min)分别增加至23±5、19±4，差异均有统计学意义（t=13.60、10.43，均P<0.05），而ΔVTI为17±8，差异无统计学意义（t=0.34，P>0.05）。回归分析发现主动脉VTI(max)、VTI(min)及ΔVTI均与禁饮禁食时长无相关性（PLR前：r=0.111、0.100、0.047；PLR后：r=0.003、0.033、0.073，均P>0.05）。多元线性回归（回退法）分析发现，无论PLR前后，年龄和体重均是IVC(RVI)和ΔVTI的影响因素（IVC(RVI)：β=-0.441、0.515、-0.451、0.507；ΔVTI：β=-0.442、0.545、-2.422、2.850；均P<0.05）。经年龄和体重校正后，禁饮禁食时长与IVC(RVI)以及ΔVTI仍无相关性（IVC(RVI)：β=0.177、0.160；ΔVTI：β=0.037、0.054；均P>0.05）。 结论： 患儿IVC直径和主动脉VTI随呼吸变异度与一定范围内的禁饮禁食时长无相关性，而与患儿的年龄和体重相关。.
Keywords: Child; Fasting; Inferior vena cava; Ultrasonography; Velocity-time integral.