压力和容量控制通气对患儿呼吸力学的影响

Effects of pressure and volume controlled ventilation on respiratory mechanics in children

目的采用自身对照的方法比较压力控制通气（PCV）和容量控制通气（VCV）对患儿术中呼吸力学及血流动力学的影响。方法全麻下择期手术患儿30例,年龄0±6个月,术前给予患儿右美托咪定负荷剂量0.1μg·kg^-1·min^-10 min内输注完毕。待患儿安静入睡,记录此时RR及呼气末二氧化碳（EtCO2）作为模拟生理睡眠状态下的RR及EtCO2。常规麻醉诱导后,顺序给予容量控制通气（VCV）及压力控制通气（PCV）,以患儿模拟生理状态下的RR为基础,调节通气压力或VT,以维持术前基础EtCO2。连续监测患儿ECG、NIBP、SpO2、RR、EtCO2、BIS及气道峰压（Ppeak）、气道平均压（Pmean）、气道平台压（Pplat）、Vt、分钟通气量（MV）、肺顺应性（Compl）等呼吸力学参数。结果 PCV 15min时患儿Ppeak值（16.8±2.9）cm H2O明显低于VCV 15min时患儿的（18.3±3.3）cm H2O,而PCV 15 min时患儿Pmean值（7.0±1.8）cm H2O明显高于VCV 15min时患儿的（6.2±1.7）cm H2O（P〈0.05）;患儿采用两种通气模式时Pplat、Vt、MV、Compl、BIS及血流动力学指标差异无统计学意义。结论两种通气模式都可安全有效地应用于新生儿和小婴儿术中机械通气,而PCV模式在预防患儿Ppeak过高、改善氧合方面更有优势。

[Abstract] Objective To investigate the effects of two different mechanical ventilation modes on respiratory mechanics in neonates and infants. Methods Thirty children aged from 0 to 6 months undergoing elective surgeries with general anesthesia were recruited. Before surgery, bolus dose of dexmedetomidine 0. 1 ·kg^-1·min^-1 was administered intravenously within 10 rain. When the children lost consciousness, RR and end-tidal dioxide （EtCO2） were measured and recorded, and used as the baselines in simulated physiological sleep state. After the induction of general anesthesia, VCV and PCV ventilation were performed in turn to maintain EtCO2 based on the RR measured before sur- gery. ECG, NIBP, SPO2, RR, EtCO2, bispectral index （BIS） and related physiologic parameters such as peak airway pressure （Ppeak）, mean airway pressure （Pmean）, airway plateau pressure （Pplat）, tidal volume （Vt）, minute ventilation （MV）, lung compliance （compl） were also recorded automatically with the Datex-Ohmeda software S/5 Collect onto the computer hard disk every 10 s for off-line analysis. Results Ppeak （16.8±2.9） cm H20 in PCV mode 15 min was lower significant- ly compared with that （18. 3±3.3） cm H20 in VCV modes 15 rain. Pmean （7.0±1.8） cm H20 in PCV mode 15 rain was higher significantly compared with that （6.2± 1.7） cm H20 with VCV mode 15 min （P〈0. 05）. No significant differences were found in Pplat, Vt, MV, Compl, BIS and hemo- dynamic parameters between both ventilation modes. Conclusion VCV and PVC modes were both safe and effective in neonates and infants during surgery. PCV mode patients have lower peak airway pressure and improve oxygenation.