Объемная капнография как способ оценки эффективности альвеолярной вентиляции в клинической практике

The purpose of the study was to compare the relationship between the dead space volume and tidal volume (VD/VT) using volumetric capnography (VCap) during pressure controlled (PCV) and pressure supported (PSV) ventilation mode in the postoperative period.Materials and methods. 30 randomly assigned cardiac surgical patients undergoing CABG (coronary artery bypass grafting) using ECC (extracorporeal circuit) were included in an observational, prospective study. Patients were connected to the ventilator immediately after ICU admission. After that, monitoring VD/VT, CO2 production (VECO2) as well as ventilation parameters was carried out. The parameters during PCV and PSV mode were statistically evaluated using t-test.Results. Expiratory CO2 (ETCO2) concentration were not significantly different in both PCV or PSV (p=NS), although both VECO2 and minute ventilation (MV) increased during PSV mode (p<0.01). VD/VT in PSV mode was lower than in PCV. Gas exchange represented by alveolar ventilation (VA) was better during PSV (p<0.01). VA was also higher during PSV (p<0.05). The calculated VD/VT ratio differed between PCV and PSV mode (p<0.01).Conclusion. VCap represents a tool for monitoring of CO2 exchange effectivness. We registered a decrease in VD/VT with improved alveolar ventilation (VA) in PSV mode. VCap seems to be a suitable instrument for adjustment of protective lung ventilation.Цель исследования — сравнить взаимосвязь между объемом мертвого пространства и дыхательным объемом (VD/VT) методом объемной капнографии (VCap) в режимах искусственной вентиляции легких с управляемым давлением (PCV) и поддержкой давлением (PSV) в послеоперационном периоде.Материалы и методы. В обсервационное, проспективное исследование методом случайного выбора включили 30 пациентов из отделения сердечно-сосудистой хирургии, перенесших операцию аортокоронарного шунтирования (АКШ) с экстракорпоральным кровообращением. Пациентов подключали к системе вентиляции легких сразу при поступлении в отделение интенсивной терапии. Затем проводили мониторинг VD/VT, продукции CO2 (VECO2), а также параметров вентиляции. Параметры вентиляции в режимах с управляемым давлением (PCV) и поддержкой давлением (PSV) статистически оценивалиРезультаты. Не выявили достоверных различий концентрации CO2 во выдыхаемом воздухе (ETCO2) между режимами PCV и PSV (p=NS), хотя как VECO2, так и минутная вентиляция (MV) возрастали в режиме PSV (p<0,01). Отношение VD/VT в режиме PSV было ниже, чем в режиме PCV. Газообмен, представленный альвеолярной вентиляцией (VA), был лучше в режиме PSV (p<0,01). Показатель VA был также выше в режиме PSV (p<0,05). Расчетное отношение VD/VT различалось между режимами PCV и PSV (p<0,01).Заключение. Объемная капнография (VCap) является средством мониторинга эффективности обмена CO2. Отмечали снижение VD/VT с улучшением альвеолярной вентиляции (VA) в режиме PSV. VCap представляется подходящим методом регулирования протективной вентиляции легких

Thyroid Hormones, Insulin, Body Fat, and Blood Biochemistry Indices in Dairy Cows During the Reproduction/Production Cycle

This study investigated the changes in: thyroid hormones, amount of subcutaneous fat, and selected indices of blood biochemistry in dairy cows in relation to the reproduction/production cycle. The blood samples were collected both ante- and post-partum every two weeks. When evaluating the mean values of the investigated indices, the major changes were recorded in dairy cows 3 to 14 days after calving. During this period, we observed a significant decrease in the mean serum levels of T3 (P < 0.05), T4 (P < 0.01), and triglycerides (P < 0.01). An opposite trend was observed with a significant increase after calving in the: mean serum levels of β-hydroxybutyrate (P < 0.05), urea (P < 0.01), and mean AST activities (P < 0.05). A significant increase over the normal range was recorded in the average levels of non-esterified fatty acids (P < 0.01) and total bilirubin (P < 0.01). From the next sampling (28 days after calving) onwards we recorded a significant increase in the blood serum levels of cholesterol (P < 0.01), total lipids (P < 0.01), total protein (P < 0.01), as well as a significant decrease in the insulin levels (P < 0.05) and a reduced layer of subcutaneous fat (P < 0.01). The blood serum iodine concentration showed only slight significant changes (P < 0.05) during the observation. Blood serum levels of glucose did not show any significant changes during the whole observation period. Within the whole observation period we found a negative correlation between T3 levels and the layer of subcutaneous fat (r = −0.2606; P < 0.05). This correlation was much more marked in cows 3 to 14 days after calving (r = −0.5077; P < 0.05), which may indicate a possible relationships between the thyroid status, body condition, and post partum negative energy balance

Volumetric Сapnography As a Tool for Evaluation of Alveolar Ventilation Effectiveness in Clinical Practice

The purpose of the study was to compare the relationship between the dead space volume and tidal volume (VD/VT) using volumetric capnography (VCap) during pressure controlled (PCV) and pressure supported (PSV) ventilation mode in the postoperative period.Materials and methods. 30 randomly assigned cardiac surgical patients undergoing CABG (coronary artery bypass grafting) using ECC (extracorporeal circuit) were included in an observational, prospective study. Patients were connected to the ventilator immediately after ICU admission. After that, monitoring VD/VT, CO2 production (VECO2) as well as ventilation parameters was carried out. The parameters during PCV and PSV mode were statistically evaluated using t-test.Results. Expiratory CO2 (ETCO2) concentration were not significantly different in both PCV or PSV (p=NS), although both VECO2 and minute ventilation (MV) increased during PSV mode (p&lt;0.01). VD/VT in PSV mode was lower than in PCV. Gas exchange represented by alveolar ventilation (VA) was better during PSV (p&lt;0.01). VA was also higher during PSV (p&lt;0.05). The calculated VD/VT ratio differed between PCV and PSV mode (p&lt;0.01).Conclusion. VCap represents a tool for monitoring of CO2 exchange effectivness. We registered a decrease in VD/VT with improved alveolar ventilation (VA) in PSV mode. VCap seems to be a suitable instrument for adjustment of protective lung ventilation