Department of Anesthesiology, University Medical Center Goettingen, Goettingen, Germany.
Department of Medical Statistics, University Medical Center Goettingen, Goettingen, Germany.
Paediatr Anaesth. 2022 Sep;32(9):1054-1061. doi: 10.1111/pan.14504. Epub 2022 Jun 14.
Core temperature monitoring is indispensable to prevent children from perioperative thermal perturbations. Although nasopharyngeal measurements are commonly used in anesthesia and considered to reflect core temperature accurately, standardized target depths for probe insertion are unknown in children.
Our primary goal was to determine a target depth of nasopharyngeal temperature probe insertion in children by measuring distances on magnetic resonance imaging (MRI). Secondary aims were to correlate these measurements with biometric variables and facial landmark-distances to derive formulas estimating target depth.
We conducted a prospective observational study in children ≤12 years undergoing cranial MRI with anesthesia. We documented patient characteristics and measured the landmark-distances nostril-mandible, nostril-tragus, and philtrum-tragus on patient's faces. On MRI, the target point for the probe tip was considered to be the site of the nasopharyngeal mucosa with the closest proximity to the internal carotid artery. After its determination in the transverse axis and triangulation to the sagittal axis, we measured the distance to the nostril. This distance, defined as target insertion depth, was correlated with the patient characteristics and used for univariate and multiple linear regression analysis.
One hundred twenty children with a mean age of 4.5 years were included. The target insertion depth ranged from 61.8 mm in infants to 89.8 mm in 12-year-old children. Height correlated best (ρ = 0.685, 95%-CI: [0.57-0.77]). The best-fit estimation in millimeters, "40.8 + height [cm] × 0.32,″ would lead to a placement in the target position in 67% of cases. A simplified approach by categories of 50-80, 80-110, 110-130, and >130 cm height with target insertion depths of 60, 70, 80, and 85 mm, respectively, achieved similar probabilities.
Height-based formulas could be a valuable proxy for the insertion depth of nasopharyngeal temperature probes. Further clinical trials are necessary to investigate their measurement accuracy.
核心体温监测对于预防儿童围手术期体温波动至关重要。尽管鼻咽测量在麻醉中被广泛应用，并且被认为能准确反映核心体温，但在儿童中，探头插入的标准化目标深度尚不清楚。
我们的主要目标是通过磁共振成像（MRI）测量来确定儿童鼻咽温度探头插入的目标深度。次要目标是将这些测量值与生物测量变量和面部标志距离相关联，以推导出估计目标深度的公式。
我们进行了一项前瞻性观察研究，纳入了 12 岁以下接受头部 MRI 检查并接受麻醉的儿童。我们记录了患者的特征，并测量了患者面部上的鼻孔-下颌、鼻孔-耳屏和人中-耳屏的标志距离。在 MRI 上，探头尖端的目标点被认为是与颈内动脉最接近的鼻咽黏膜部位。在确定了横轴上的目标点位置并与矢状轴进行三角测量后，我们测量了到鼻孔的距离。这个距离被定义为目标插入深度，与患者的特征相关联，并用于单变量和多元线性回归分析。
共纳入 120 名平均年龄为 4.5 岁的儿童。目标插入深度范围从婴儿的 61.8 毫米到 12 岁儿童的 89.8 毫米。身高相关性最好（ρ=0.685，95%置信区间：[0.57-0.77]）。最佳拟合毫米数的估计值为“40.8+身高[cm]×0.32”，将探头放置在目标位置的概率为 67%。通过身高分为 50-80、80-110、110-130 和>130cm 三个类别，目标插入深度分别为 60、70、80 和 85mm 的简化方法，也能达到相似的概率。
基于身高的公式可以作为鼻咽温度探头插入深度的有价值替代指标。还需要进一步的临床试验来研究其测量准确性。
