Bukoski Alex, Downs John, Hodgson David S, Le-Bert Carolina R, Thomen Robert, Flors Lucia, Thombs Lori, Bailey James
Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO, United States.
Innovative Veterinary Medicine, Ponte Vedra, FL, United States.
Front Vet Sci. 2024 May 24;11:1378617. doi: 10.3389/fvets.2024.1378617. eCollection 2024.
To compare the cardiopulmonary effects of apneustic anesthesia ventilation (AAV) and conventional mechanical ventilation (CMV) in anesthetized pigs and to describe a new mode of ventilation for anesthetized veterinary species.
Randomized, crossover design without washout.
Twelve healthy, female white Landrace pigs.
Following ketamine-midazolam premedication and anesthetic induction with propofol, the trachea was intubated, and each pig was positioned in dorsal recumbency. Anesthesia was maintained with propofol and sufentanil infusions. Pigs were instrumented and their lungs were sequentially ventilated with each mode, in random order, for 1 h according to predefined criteria [fraction of inspired oxygen (FiO) = 0.21, 10 mL kg tidal volume (V), and arterial carbon dioxide tension (PaCO) within 40-45 mmHg]. Cardiopulmonary data were collected at baseline, 30 and 60 min. In 8 pigs, thoracic computed tomography (CT) was performed following the 60 min time point for each mode of ventilation and images were analyzed to quantify lung aeration. The effects of ventilation mode, time, and order were analyzed using repeated measures ANOVA. Paired -tests were used to compare lung aeration between modes. Significance was defined as < 0.05.
Data from 12 pigs were analyzed. A significant effect of mode was found for heart rate, mean arterial pressure (MAP), pulmonary artery occlusion pressure, cardiac index (CI), stroke volume index, systemic vascular resistance, pulmonary vascular resistance, oxygen delivery index (DOI), oxygen extraction ratio (OER), V, arterial oxygen tension, arterial hemoglobin saturation, PaCO, end-tidal carbon dioxide tension, alveolar dead space (V/V), venous admixture ( ), mean airway pressure, and dynamic compliance index (CI). Order effects were also observed for some cardiovascular and respiratory variables. For the eight pigs that underwent thoracic CT, AAV resulted in significantly larger proportions of normally and hyperaerated lung while CMV resulted in larger proportions of hypoaerated and atelectatic lung.
In dorsally recumbent anesthetized pigs, ventilated with FiO = 0.21, both modes of ventilation supported adequate oxygenation while AAV resulted in higher CI, and lower V/V and , compared with CMV. AAV was also associated with lower MAP, CI, and DOI and higher OER compared with CMV. Further investigation of AAV in anesthetized animals is warranted.
比较深慢呼吸麻醉通气（AAV）与传统机械通气（CMV）对麻醉猪心肺功能的影响，并描述一种用于麻醉动物的新型通气模式。
无洗脱期的随机交叉设计。
12头健康雌性白色长白猪。
用氯胺酮-咪达唑仑进行术前用药，丙泊酚诱导麻醉后，进行气管插管，每头猪取仰卧位。用丙泊酚和舒芬太尼持续输注维持麻醉。根据预定义标准（吸入氧分数[FiO]=0.21、潮气量[V]10 mL/kg、动脉二氧化碳分压[PaCO]在40-45 mmHg之间），对猪进行仪器监测，并按随机顺序依次用每种模式对其肺进行1小时通气。在基线、30分钟和60分钟时收集心肺数据。在8头猪中，每种通气模式在60分钟时间点后进行胸部计算机断层扫描（CT），并分析图像以量化肺通气情况。使用重复测量方差分析来分析通气模式、时间和顺序的影响。配对t检验用于比较不同模式之间的肺通气情况。显著性定义为P<0.05。
分析了12头猪的数据。发现模式对心率、平均动脉压（MAP）、肺动脉闭塞压、心脏指数（CI）、每搏量指数、全身血管阻力、肺血管阻力、氧输送指数（DOI）、氧摄取率（OER）、V、动脉血氧分压、动脉血红蛋白饱和度、PaCO、呼气末二氧化碳分压、肺泡死腔（V/V）、静脉血掺杂（ ）、平均气道压和动态顺应性指数（CI）有显著影响。对于一些心血管和呼吸变量也观察到顺序效应。对于接受胸部CT的8头猪，AAV导致正常通气和过度通气肺的比例显著更大，而CMV导致通气不足和肺不张肺的比例更大。
在仰卧位麻醉猪中用FiO=0.21通气时，两种通气模式均能维持充分的氧合，但与CMV相比，AAV导致更高的CI、更低的V/V和 。与CMV相比，AAV还与更低的MAP、CI和DOI以及更高的OER相关。有必要对麻醉动物中的AAV进行进一步研究。
