Li Pan, Wang Weiping, Gao Wen, Tan Yanling, Hu Yu, Jiang Li
Department of Anesthesiology, Children's Hospital of Chongqing Medical University National Clinical Research Center for Child Health and Disorders Ministry of Education Key Laboratory of Child Development and Disorders Chongqing Key Laboratory of Child Neurodevelopment and Cognitive Disorders Chongqing China.
Department of Neurology, Children's Hospital of Chongqing Medical University National Clinical Research Center for Child Health and Disorders Ministry of Education Key Laboratory of Child Development and Disorders Chongqing Key Laboratory of Child Neurodevelopment and Cognitive Disorders Chongqing China.
Pediatr Discov. 2024 Aug 4;2(3):e2502. doi: 10.1002/pdi3.2502. eCollection 2024 Sep.
The circle breathing system was unsafe for spontaneous breathing because of hypercapnia during anesthesia. Few studies have examined the minimizing dead space in breathing tubing. This study investigated one-way valves in the breathing tubing during spontaneous breathing in piglets. Six female piglets aged 68-71 days spontaneously breathed sevoflurane for 4 h randomly via traditional or anti-rebreathing tubing. Arterial carbon dioxide tension (paCO) and respiratory characteristics were used to assess spontaneous breathing efficiency. mRNA-based methods, immunohistochemistry, and histology were used to assess the lungs. After induction, all piglets had mild hypercapnia. Those who breathed via traditional tubing experienced severe hypercapnia and required assisted ventilation (mean [95% confidence interval for mean]: 3 [0.5; 5.5] times) over 4 h. Piglets who breathed via anti-rebreathing tubing were able to normalize without assisted ventilation in less than 3 h and maintained. paCO was higher in the traditional group than the anti-rebreathing group at 3 and 4 hours (46.3 [42.1; 50.5] vs. 38.3 [34.1; 42.5] mmHg, = 0.020; 46.3 [42.6; 50.0] vs. 40.7 [37.0; 44.4] mmHg, = 0.040). However, one-way valves increased resistance to breathing. For the lungs, mRNA-based methods indicated higher expressions of cyclin-dependent kinase, cell division cycle 20, and cyclin B2 in the traditional group; immunohistochemistry identified higher expression of phosphorylated histone 2AX in the traditional group; histology showed similar damage between the groups. These findings suggest that one-way valves inside breathing tubing reduced dead space during spontaneous breathing and enhanced inhalation anesthesia advantages in the circle breathing system.
由于麻醉期间存在高碳酸血症，循环呼吸系统对于自主呼吸不安全。很少有研究探讨如何最小化呼吸管路中的死腔。本研究调查了仔猪自主呼吸期间呼吸管路中的单向阀。六只68 - 71日龄的雌性仔猪通过传统或防复吸管路随机自主呼吸七氟醚4小时。采用动脉血二氧化碳分压（paCO）和呼吸特征来评估自主呼吸效率。使用基于mRNA的方法、免疫组织化学和组织学来评估肺部情况。诱导后，所有仔猪均出现轻度高碳酸血症。通过传统管路呼吸的仔猪出现严重高碳酸血症，在4小时内需要辅助通气（平均值[平均值的95%置信区间]：3[0.5；5.5]次）。通过防复吸管路呼吸的仔猪在不到3小时内无需辅助通气即可恢复正常并维持。在3小时和4小时时，传统组的paCO高于防复吸组（46.3[42.1；50.5]对38.3[34.1；42.5]mmHg，P = 0.020；46.3[42.6；50.0]对40.7[37.0；44.4]mmHg，P = 0.040）。然而，单向阀增加了呼吸阻力。对于肺部，基于mRNA的方法表明传统组中细胞周期蛋白依赖性激酶、细胞分裂周期20和细胞周期蛋白B2的表达较高；免疫组织化学鉴定出传统组中磷酸化组蛋白2AX的表达较高；组织学显示两组之间的损伤相似。这些发现表明，呼吸管路内的单向阀在自主呼吸期间减少了死腔，并增强了循环呼吸系统中吸入麻醉的优势。
