正压机械通气与膈肌起搏联合通气对呼吸衰竭患者呼吸力学的影响

目的 观察正压机械通气与膈肌起搏联合通气对呼吸衰竭(呼衰)患者呼吸力学的影响.方法 采用自身前后对照研究方法,以20例中枢性呼衰患者先使用常规正压机械通气30 min作为对照组,后改用正压机械通气与膈肌起搏联合通气30 min作为试验组,观察两种通气方式下患者的呼吸力学变化.结果 与对照组比较,试验组平均气道压(Paw,cm H2O,1 cm H2O=0.098 kPa)、平台压(Pplat,cm H2O)明显降低(Paw:6.1±1.3比7.3±1.8;Pplat:10.4±2.5比12.1±2.6,均P＜0.05),峰食道压力(PPEAK ES,cm H2O)、峰食道压力与基准食道压力差(dPES,cm H2O)负值明显增加(PPEAK ES:-8.3±1.9比-3.2±1.4;dPES:-11.2±2.6比-8.2±2.2,均P＜0.05),吸气末屏气期间的跨肺压(Ptp plat,cm H2O)、呼吸系统静态顺应性(Cst,ml/cm H2O)明显增加(Ptp plat:23.6±3.8比15.6±3.1 Cst:52.7±8.2比48.3±7.2,均P＜0.05),气道阻力(Raw,cm H2O·L-1·s-1)、肺部阻力(RL,cm H2O·L-1·s-1)无明显改变(Raw:2.1±0.5比2.3±0.4; RL:2.9±0.6比3.1±0.5,均P＞0.05),患者呼吸功(WOBp,J/L)明显增加、机械呼吸功(WOBv,J/L)明显降低(WOBp:0.18±0.03比0;WOBv:0.31±0.07比0.53±0.11,均P＜0.05).结论 正压机械通气与膈肌起搏联合通气进行呼吸支持可明显降低呼衰患者气道压力,增加胸腔内压负值和跨肺压,提高肺顺应性,并能降低机械通气作功,但对气道阻力无明显影响.

Abstract：

Objective To observe the effects of combining positive pressure ventilation with diaphragm pacing on respiratory mechanics in patients with respiratory failure. Methods Twenty patients with central respiratory failure were studied with cohorts. The effects on respiratory mechanics were respectively observed in patients in control group, in whom ventilation by positive pressure only, and patients in experimental group in whom ventilation was instituted by combining positive pressure ventilation with diaphragm pacing. Results Compared with control group, mean airway pressure (Paw, cm H2O,1 cm H2O= 0. 098 kPa) and plateau pressure (Pplat, cm H2O) were significantly decreased in experimental group (Paw: 6. 1±1.3 vs. 7. 3±1.8; Pplat: 10. 4±2.5 vs. 12. 1±2. 6, both P＜0. 05), while the nagative value of peak esophageal pressure (PPEAK ES, cm H2O), the nagative value of the difference between peak and basic esophageal pressure (dPES, cm H2O), transpulmonary pressure at end of inspiration hold (Ptp plat,cm H2O), static compliance (Cst, ml/cm H2O) were significantly increased in experimental group (PPEAKES:-8.3±1.9 vs. -3.2±1.4; dPES: -11.2±2.6 vs. -8. 2±2. 2; Ptp plat: 23.6±3.8 vs. 15.6±3.1; Cst:52. 7±8. 2 vs. 48. 3 ±7. 2, all P ＜ 0. 05 ). No differences were found in airway resistance (Raw,cm H2O · L-1 · s-1) and lung resistance (RL, cm H2O · L-1 · s-1) between experimental group and control group (Raw: 2.1±0.5 vs. 2.3±0.4; RL: 2.9±0.6 vs. 3.1±0.5, both P＞0.05). Work of breath by patient (WOBp, J/L) was significantly increased and work of breath by ventilator (WOBv, J/L) was significantly decreased in experimental group compared with control group (WOBp: 0. 18± 0. 03 vs. 0;WOBv: 0.31±0.07 vs. 0.53±0.11, both P＜0.05). Conclusion Compared with positive pressure ventilation, positive pressure ventilation combined with diaphragm pacing can decrease the Paw, increase intrathoracic negative pressure, transpulmonary pressure, and Cst, and decrease WOBv, while there is no effect on Raw and RL.

The effect of positive pressure ventilation combined with diaphragm pacing on respiratory mechanics in patients with respiratory failure

Objective To observe the effects of combining positive pressure ventilation with diaphragm pacing on respiratory mechanics in patients with respiratory failure. Methods Twenty patients with central respiratory failure were studied with cohorts. The effects on respiratory mechanics were respectively observed in patients in control group, in whom ventilation by positive pressure only, and patients in experimental group in whom ventilation was instituted by combining positive pressure ventilation with diaphragm pacing. Results Compared with control group, mean airway pressure (Paw, cm H2O,1 cm H2O= 0. 098 kPa) and plateau pressure (Pplat, cm H2O) were significantly decreased in experimental group (Paw: 6. 1±1.3 vs. 7. 3±1.8; Pplat: 10. 4±2.5 vs. 12. 1±2. 6, both P＜0. 05), while the nagative value of peak esophageal pressure (PPEAK ES, cm H2O), the nagative value of the difference between peak and basic esophageal pressure (dPES, cm H2O), transpulmonary pressure at end of inspiration hold (Ptp plat,cm H2O), static compliance (Cst, ml/cm H2O) were significantly increased in experimental group (PPEAKES:-8.3±1.9 vs. -3.2±1.4; dPES: -11.2±2.6 vs. -8. 2±2. 2; Ptp plat: 23.6±3.8 vs. 15.6±3.1; Cst:52. 7±8. 2 vs. 48. 3 ±7. 2, all P ＜ 0. 05 ). No differences were found in airway resistance (Raw,cm H2O · L-1 · s-1) and lung resistance (RL, cm H2O · L-1 · s-1) between experimental group and control group (Raw: 2.1±0.5 vs. 2.3±0.4; RL: 2.9±0.6 vs. 3.1±0.5, both P＞0.05). Work of breath by patient (WOBp, J/L) was significantly increased and work of breath by ventilator (WOBv, J/L) was significantly decreased in experimental group compared with control group (WOBp: 0. 18± 0. 03 vs. 0;WOBv: 0.31±0.07 vs. 0.53±0.11, both P＜0.05). Conclusion Compared with positive pressure ventilation, positive pressure ventilation combined with diaphragm pacing can decrease the Paw, increase intrathoracic negative pressure, transpulmonary pressure, and Cst, and decrease WOBv, while there is no effect on Raw and RL.