不同干预措施对犬急性肺损伤早期中枢驱动和呼吸应答的影响

Effects of different intervention strategies on central drive and respiratory response during early stage of acute lung injury in canine models

目的探讨早期应用控制性高浓度氧疗、持续气道内正压(CPAP)、双水平气道内正压(BiPAP)等不同的干预措施对犬急性肺损伤(ALI)早期中枢驱动和呼吸应答的影响。方法24只杂种犬在制作油酸急性肺损伤模型成功后(PaO_2/FiO_2≤300 mm Hg),保持自主呼吸,随机分为控制性高浓度氧疗组(n=8)、CPAP组(n=8)、BiPAP组(n=8)。连续记录并计算正常、ALI早期、干预后1～4 h内中枢驱动和呼吸应答的各项生理指标。结果在降低呼吸频率上,BiPAP组效果最明显(P<0.001),其次是CPAP组和氧疗组(P<0.05)。三组对分钟通气量的影响不大(P>0.05),维持在ALI或急性呼吸窘迫综合征(ARDS)发生后的通气水平。在潮气量、吸气流量峰值、平均吸气流量指标的改善上,BiPAP组效果最显著,其次是CPAP组和氧疗组。在跨膈压峰值、膈肌肌电电压最大均方根上,BiPAP组降低最明显,其次是CPAP组。结论BiPAP和CPAP对于缓解呼吸窘迫、降低呼吸中枢驱动、改善呼吸应答均具有积极作用,显著延缓了ALI/ARDS的病情恶化,其中BiPAP效果更为显著。

Objective To evaluate the effects of different intervention strategies such as high-concentration controlled oxygen therapy, constant positive airway pressure （CPAP） or hi-level positive airway pressure （BiPAP） ventilation on central drive and respiratory response in early stage of acute lung injury （ALI） in canine models. Methods After the completion of oleic acid induced acute lung injury （diagnostic standard： PaOE/FiO2≤300 mm Hg）, the 24 adult mongrel dogs were randomly divided into 3 groups： high-concentration controlled oxygen therapy group （n=8）, CPAP group （n=8） and BiPAP group （n=8）. Monitor continuously and calculate the parameters on central drive and respiratory response before injury, in early stage after injury, and 1-4 h after treatment. Results BiPAP had most significant effects on reducing respiratory rate （P〈0.001）, and next to it were CPAP and controlled oxygen therapy （P〈0.001）. The three groups had no obvious effects on minute ventilation （P〉0.05）, which maintained the level of early ALI/acute respiratory distress syndrome （ARDS） stage. BiPAP greatly improved tidal volume （VT）, Vinsp, peak and VT/Ti, and the next were CPAP and controlled oxygen therapy. BiPAP greatly decelerated the levels of Pdi, peak and RMSmax, and next to it was CPAP. Conclusion BiPAP and CPAP exert active effects on releasing dyspnea, decreasing respiratory central drive and improving respiratory response, which obviously control the deterioration of ARDS. BiPAP displays more significant therapeutic effects than CPAP and oxygen therapy do.