The effects of cardiac output and pulmonary arterial hypertension on volumetric capnography derived-variables during normoxia and hypoxia

作者：Mosing Martina^*; Kutter Annette P N; Iff Samuel; Raszplewicz Joanna; Mauch Jacqueline; Bohm Stephan H; Tusman Gerardo

来源：Journal of Clinical Monitoring and Computing, 2015, 29(1): 187-196.

DOI：10.1007/s10877-014-9588-0

• Cardiovascular changes
• Pig
• Pulmonary hypertension
• Slope of phase III
• Volumetric capnography

The aim of this study was to test the effect of cardiac output (CO) and pulmonary artery hypertension (PHT) on volumetric capnography (VCap) derived-variables. Nine pigs were mechanically ventilated using fixed ventilatory settings. Two steps of PHT were induced by IV infusion of a thromboxane analogue: PHT25 [mean pulmonary arterial pressure (MPAP) of 25 mmHg] and PHT40 (MPAP of 40 mmHg). CO was increased by 50 % from baseline (COup) with an infusion of dobutamine a parts per thousand yen5 mu g kg(-1) min(-1) and decreased by 40 % from baseline (COdown) infusing sodium nitroglycerine a parts per thousand yen30 mu g kg(-1) min(-1) plus esmolol 500 mu g kg(-1) min(-1). Another state of PHT and COdown was induced by severe hypoxemia (FiO(2) 0.07). Invasive hemodynamic data and VCap were recorded and compared before and after each step using a mixed random effects model. Compared to baseline, the normalized slope of phase III (Sn-III) increased by 32 % in PHT25 and by 22 % in PHT40. Sn-III decreased non-significantly by 4 % with COdown. A combination of PHT and COdown associated with severe hypoxemia increased Sn-III by 28 % compared to baseline. The elimination of CO2 per breath decreased by 7 % in PHT40 and by 12 % in COdown but increased only slightly with COup. Dead space variables did not change significantly along the protocol. At constant ventilation and body metabolism, pulmonary artery hypertension and decreases in CO had the biggest effects on the Sn-III of the volumetric capnogram and on the elimination of CO2.

• 出版日期2015-2