Objective

To describe an approach for ethmoidal nerve block (E_BLOCK) and to compare the effects of a maxillary nerve block (M_BLOCK), E_BLOCK and their combination (M-E_BLOCK) on heart rate (HR), systolic (SAP), mean (MAP), diastolic (DAP) arterial pressures and respiratory rate (f_R) during nasal stimulation in dogs.

Study design

Prospective, blinded, randomized, crossover placebo-controlled study.

Animals

Beagle dogs (five cadavers, nine live dogs), with a median (interquartile range) weight of 10.5 (10.3–11.0) kg.

Methods

The accuracy of iohexol injections (each 1 mL) at the maxillary and ethmoidal foramina in cadavers was evaluated using computed tomography. Then, anesthetized dogs were administered four bilateral treatments separated by 1 week, saline or 2% lidocaine 1 mL per injection: injections of saline at the maxillary and ethmoidal foramina (Control), injections of lidocaine at the maxillary foramina and saline at the ethmoidal foramina (M_BLOCK), injections of saline at the maxillary foramina and lidocaine at the ethmoidal foramina (E_BLOCK) and injections of lidocaine at all foramina (M-E_BLOCK). The ventral nasal meatus was bilaterally stimulated using cotton swabs, and HR, SAP, MAP, DAP and f_R were continuously recorded. Values for each variable were compared before and after stimulation using Wilcoxon signed-rank test. Changes in variables among treatments were analyzed using Mann–Whitney U and Kruskal–Wallis tests (p ≤ 0.05).

Results

Computed tomography revealed iohexol distribution around the openings of the target foramina in all cadavers. In living dogs, HR, SAP, MAP, DAP and f_R significantly increased after stimulation within each treatment (p < 0.03). Physiologic responses were significantly attenuated, but not absent, in the M-E_BLOCK [HR (p = 0.019), SAP, MAP, DAP and f_R (all p ≤ 0.001)] compared with those in the Control.

Conclusions and clinical relevance

Concurrent injections of lidocaine at the maxillary and ethmoidal foramina attenuated HR, arterial pressure and f_R responses to nasal stimulation in Beagle dogs.

中文翻译：

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上颌神经阻滞、筛神经阻滞及其联合对麻醉比格犬鼻腔刺激心肺反应的影响

客观的

描述筛神经阻滞 (E _BLOCK )的方法，并比较上颌神经阻滞 (M _BLOCK )、E _BLOCK及其组合 (ME _BLOCK ) 对心率 (HR)、收缩压 (SAP)、平均 ( MAP)、舒张压 (DAP) 动脉压和呼吸频率 ( f _R ) 在狗的鼻刺激期间。

学习规划

前瞻性、盲法、随机、交叉安慰剂对照研究。

动物

比格犬（五具尸体，九只活狗），体重中位数（四分位距）为 10.5 (10.3–11.0) kg。

方法

使用计算机断层扫描评估尸体上颌孔和筛孔注射碘海醇（每次 1 mL）的准确性。然后，对麻醉的狗进行四次双侧治疗，间隔 1 周，每次注射盐水或 2% 利多卡因 1 mL：在上颌和筛孔注射盐水（对照），在上颌孔注射利多卡因和在筛孔注射盐水(M _BLOCK )，在上颌孔注射生理盐水，在筛孔注射利多卡因(E _BLOCK )，在所有孔注射利多卡因 (ME _BLOCK )。使用棉签双侧刺激腹侧鼻道，HR、SAP、MAP、DAP 和f _R被连续记录。使用 Wilcoxon 符号秩检验在刺激前后比较每个变量的值。使用 Mann-Whitney U和 Kruskal-Wallis 检验分析处理之间变量的变化（p ≤ 0.05）。

结果

计算机断层扫描显示所有尸体的目标孔开口周围都有碘海醇分布。在活体犬中，每次治疗后刺激后HR、SAP、MAP、DAP 和f _R显着增加（p < 0.03）。与对照组相比，ME _BLOCK [HR ( p  = 0.019)、SAP、MAP、DAP 和f _R (所有p ≤ 0.001)] 中的生理反应显着减弱，但并非不存在。

结论和临床相关性

在上颌孔和筛孔处同时注射利多卡因可减弱比格犬的HR、动脉压和f _R对鼻刺激的反应。