Abstract:Objective: To investigate the effects of different tidal volumes and positive end-expiratory pressure (PEEP) lung protective ventilation strategies on respiratory function and hemodynamics in COPD rat models. Methods: COPD rat models were established by smoke inhalation and intratracheal administration of lipopolysaccharide (LPS). Rats were randomly divided into 9 groups (10 rats per group): control and COPD groups received tracheal intubation only without mechanical ventilation; L+P0 group, L+P3 group, L+P5 group, and L+P10 group received mechanical ventilation with 6 ml/kg tidal volume and 0 cm H2O, 3 cm H2O, 5 cm H2O, and 10 cm H2O PEEP, respectively, for 120 min after tracheal intubation; H+P0 group, H+P3 group, H+P5 group, and H+P10 group received mechanical ventilation with 20 ml/kg tidal volume and 0 cm H2O, 3 cm H2O, 5 cm H2O, and 10 cm H2O PEEP, respectively, for 120 min after tracheal intubation. Respiratory function and hemodynamic parameters were measured using a small animal non-invasive respiratory function monitoring system and blood gas analyzer. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of inflammatory mediators in lung tissue and bronchoalveolar lavage fluid (BALF). Results: Compared with the control group, COPD rats showed significantly decreased respiratory function parameters and PaO2 (P<0.05); compared with the COPD group, L+P0 group, L+P3 group, and L+P5 group showed significantly increased respiratory function parameters and PaO2 (P<0.05), while L+P10 group, H+P0 group, H+P3 group, H+P5 group, and H+P10 group showed significantly decreased respiratory function parameters and PaO2 (P<0.05); L+P5 group showed significantly higher respiratory function parameters and PaO2 than L+P0 group and L+P3 group (P<0.05); compared with L+P5 group, L+P10 group, H+P0 group, H+P3 group, H+P5 group, and H+P10 group showed significantly decreased respiratory function parameters and PaO2 (P<0.05). Compared with the control group, COPD rats showed significantly increased levels of IL-8 and TNF-α in lung tissue and BALF, while IL-10 levels were significantly decreased (P<0.05); compared with the COPD group, L+P0 group, L+P3 group, and L+P5 group showed significantly decreased levels of IL-8 and TNF-α and significantly increased levels of IL-10 (P<0.05), while L+P10 group, H+P0 group, H+P3 group, H+P5 group, and H+P10 group showed significantly increased levels of IL-8 and TNF-α and significantly decreased levels of IL-10 (P<0.05); L+P5 group showed significantly lower levels of IL-8 and TNF-α in lung tissue and significantly higher levels of IL-10 than L+P0 group and L+P3 group (P<0.05); compared with L+P5 group, L+P10 group, H+P0 group, H+P3 group, H+P5 group, and H+P10 group showed significantly increased levels of IL-8 and TNF-α and significantly decreased levels of IL-10 (P<0.05). Conclusion: Lung protective ventilation strategies with low tidal volume and higher PEEP (such as 5 cm H2O PEEP) can alleviate lung inflammation and lung injury in COPD rats, improve respiratory function and hemodynamics in COPD patients.
[1] 李然,刘晓芳,孙永昌,等.稳定期慢性阻塞性肺疾病患者十年死亡危险因素分析[J].中华全科医师杂志,2021,20(11):1134-1140 [2] Scaramuzzo G,Ottaviani I,Volta CA,et al.Mechanical ventilation and COPD:from pathophysiology to ventilatory management[J].Minerva Med,2022,113(3):460-470. [3] Zhang J,Wang X,Xie J,et al.Effects of THE PEEP-ZEEP maneuver in adults receiving mechanical ventilation:a systematic review with meta-analysis[J].Heart Lung,2024(63):159-166. [4] Shiber J.Tidal volume should be individualized to the patient's lung compliance[J].Ann Emerg Med,2023,82(2):239-240. [5] 刘军,张辉,石颖,等.不同潮气量机械通气对急性呼吸窘迫综合征大鼠右心血流动力学的影响[J].中华危重急救医学,2021,1(33):49-52. [6] 王全红,沈锋.不同水平呼气末正压通气对急性肺损伤/急性呼吸窘迫综合征大鼠水通道蛋白1和5的影响[J].中华结核和呼吸杂志,2012,35(9):706-707 [7] Bravo DM,Gimenes AC,Amorim BC,et al.Excess ventilation in COPD:Implications for dyspnoea and tolerance to interval exercise[J].Respir Physiol Neurobiol,2018(250):7-13. [8] 黄晓南,于绍飞,许清琴.以Ptp导向选择最佳PEEP治疗ARDS患者的效果及其对血气指标、呼吸力学水平的影响[J].医学理论与实践,2022,35(13):2211-2213. [9] Beitler JR,Sarge T,Banner-Goodspeed VM,et al.Effect of titrating positive end-expiratory pressure (PEEP) with an esophageal pressure-guided strategy vs an empirical high PEEP-FiO2 strategy on death and days free from mechanical ventilation among patients with acute respiratory distress syndrome:a randomized clinical trial[J].JAMA,2019,321(9):846-857. [10] R S,M N,L D,et al.Could disease severity and inflammatory markers (IL-6,Hs-CRP,TNF-α) be related to frailty in COPD A prospective study[J].Assoc Physicians India,2022,70(4):11-12. [11] Demoule A,Brochard L,Dres M,et al.How to ventilate obstructive and asthmatic patients[J].Intensive Care Med,2020,46(12):2436-2449.