Effects of lung protective mechanical ventilation associated with permissive respiratory acidosis on regional extra-pulmonary blood flow in experimental ARDS

BMC Anesthesiology

Research Article

Stefan Kreyer¹  Christian Putensen¹  Rudolf Hering² 

[1] Department of Anesthesia and Intensive Care Medicine, University Hospital of Bonn, Bonn, Germany;Department of Anesthesia and Intensive Care Medicine, University Hospital of Bonn, Bonn, Germany;Department of Anesthesia, Intensive Care, Emergency and Pain Medicine, Kreiskrankenhaus Mechernich GmbH, Mechernich, Germany;

关键词: Cardiac output;    Lung protective ventilation;    Respiratory distress syndrome;    Regional blood flow;    Hemodynamics;    Permissive hypercapnia;   

DOI  :  10.1186/s12871-017-0439-7

 received in 2017-06-26, accepted in 2017-10-19,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundLung protective mechanical ventilation with limited peak inspiratory pressure has been shown to affect cardiac output in patients with ARDS. However, little is known about the impact of lung protective mechanical ventilation on regional perfusion, especially when associated with moderate permissive respiratory acidosis. We hypothesized that lung protective mechanical ventilation with limited peak inspiratory pressure and moderate respiratory acidosis results in an increased cardiac output but unequal distribution of blood flow to the different organs of pigs with oleic-acid induced ARDS.MethodsTwelve pigs were enrolled, 3 died during instrumentation and induction of lung injury. Thus, 9 animals received pressure controlled mechanical ventilation with a PEEP of 5 cmH2O and limited peak inspiratory pressure (17 ± 4 cmH2O) versus increased peak inspiratory pressure (23 ± 6 cmH2O) in a crossover-randomized design and were analyzed. The sequence of limited versus increased peak inspiratory pressure was randomized using sealed envelopes. Systemic and regional hemodynamics were determined by double indicator dilution technique and colored microspheres, respectively. The paired student t–test and the Wilcoxon test were used to compare normally and not normally distributed data, respectively.ResultsMechanical ventilation with limited inspiratory pressure resulted in moderate hypercapnia and respiratory acidosis (PaCO2 71 ± 12 vs. 46 ± 9 mmHg, and pH 7.27 ± 0.05 vs. 7.38 ± 0.04, p < 0.001, respectively), increased cardiac output (140 ± 32 vs. 110 ± 22 ml/min/kg, p<0.05) and regional blood flow in the myocardium, brain and spinal cord, adrenal and thyroid glands, the mucosal layers of the esophagus and jejunum, the muscularis layers of the esophagus and duodenum, and the gall and urinary bladders. Perfusion of kidneys, pancreas, spleen, hepatic arterial bed, and the mucosal and muscularis blood flow to the other evaluated intestinal regions remained unchanged.ConclusionsIn this porcine model of ARDS mechanical ventilation with limited peak inspiratory pressure resulting in moderate respiratory acidosis was associated with an increase in cardiac output. However, the better systemic blood flow was not uniformly directed to the different organs. This observation may be of clinical interest in patients, e.g. with cardiac, renal and cerebral pathologies.

【 授权许可】

CC BY   
© The Author(s). 2017