Madson Zachary C, Vangala Sitaram, Sund Grace T, Lin James A
Pediatric Hospitalist Medicine, Lutheran Children's Hospital, Fort Wayne, IN 46804, United States.
Medicine Statistics Core, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States.
World J Clin Pediatr. 2020 Sep 19;9(2):17-28. doi: 10.5409/wjcp.v9.i2.17.
Critically ill neonates and pediatric patients commonly require multiple low flow infusions. Volume limitations are imposed by small body habitus and co-morbidities like cardiopulmonary disease, renal failure, or fluid overload. Vascular access is limited by diminutive veins. Maintenance fluids or parenteral nutrition in conjunction with actively titrated infusions such as insulin, fentanyl, prostaglandins, inotropes and vasopressors may necessitate simultaneous infusions using a single lumen to maintain vascular catheter patency. This requirement for multiple titratable infusions requires concentrated medications at low flows, rather than more dilute drugs at higher flows that in combination may volume overload small infants.
To determine whether carrier fluid reduces variability that variability of low flow drug infusions is proportional to syringe size in pediatric critical care.
We assessed concentrations of orange "drug" in a 0.2 mL/h low flow clinical model with blue dyed carrier fluid at 5 mL/h, using 3-, 10-, or 60-mL syringes. A graduated volumetric pipette was used to measure total flow. Mean time to target concentration was 30, 21, and 46 min in 3-, 10-, and 60-mL syringes, respectively ( = 0.42). After achieving target concentration, more dilute drug was delivered by 60-mL ( < 0.001) and 10-mL syringes ( = 0.04) compared to 3-mL syringes. Drug overdoses were observed during the initial 45 min of infusion in 10-and 60-mL syringes. Total volumes infused after target concentration were less in the 60-mL condition compared to 3-mL ( < 0.01) and 10-mL ( < 0.001) syringes.
Linear mixed effects models demonstrated lesser delivered drug concentrations in the initial 30 min by 3-mL compared to 10-and 60-mL syringes ( = 0.005 and < 0.001, respectively) but greater drug concentrations and total infused drug in the subsequent 30-60 and 60-90 min intervals with the 3- and 10-mL compared to 60-mL syringes.
With carrier fluid, larger syringes were associated with significantly less drug delivery, less total volume delivered, and other flow problems in our low flow drug model. Carrier fluid should not be used to compensate for inappropriately large syringes in critical low flow drug infusions.
危重新生儿和儿科患者通常需要多次低流量输注。由于体型小以及存在诸如心肺疾病、肾衰竭或液体超负荷等合并症，会限制液体量。血管通路因静脉细小而受限。维持性补液或肠外营养，再加上如胰岛素、芬太尼、前列腺素、血管活性药物和血管加压素等需要积极滴定的输注药物，可能需要使用单腔同时输注以维持血管导管通畅。这种对多种可滴定输注的需求要求在低流量下使用浓缩药物，而不是在高流量下使用更稀释的药物，因为高流量下多种药物组合可能会使小婴儿出现容量超负荷。
确定在儿科重症监护中，载体液是否能减少低流量药物输注的变异性，以及低流量药物输注的变异性是否与注射器大小成正比。
我们在一个低流量临床模型中评估了橙色“药物”的浓度，该模型以5 mL/h的速度输注蓝色染色的载体液，药物输注速度为0.2 mL/h，分别使用3 mL、10 mL或60 mL的注射器。使用分度移液管测量总流量。在3 mL、10 mL和60 mL注射器中，达到目标浓度的平均时间分别为30分钟、21分钟和46分钟（P = 0.42）。达到目标浓度后，与3 mL注射器相比，60 mL（P < 0.001）和10 mL注射器（P = 0.04）输送的药物更稀释。在输注的最初45分钟内，在10 mL和60 mL注射器中观察到药物过量。与3 mL（P < 0.01）和10 mL（P < 0.001）注射器相比，60 mL注射器在达到目标浓度后输注的总体积更少。
线性混合效应模型显示，在最初30分钟内，3 mL注射器输送的药物浓度低于10 mL和60 mL注射器（分别为P = 0.005和P < 0.001），但在随后的30 - 60分钟和60 - 90分钟间隔内，与60 mL注射器相比，3 mL和10 mL注射器输送的药物浓度更高，输注的药物总量也更多。
在我们的低流量药物模型中，对于载体液而言，较大的注射器与显著更少的药物输送量、更少的总体输送量以及其他流量问题相关。在关键的低流量药物输注中，不应使用载体液来补偿不适当的大注射器。
