Journal of clinical monitoring and computing
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J Clin Monit Comput · Dec 2017
The influence of PEEP and positioning on central venous pressure and venous hepatic hemodynamics in patients undergoing liver resection.
In order to assess the occurrence of blood congestion in the liver during liver resection, we aimed to evaluate the influence of a positive-end-expiratory-pressure (PEEP) and positioning of patients on central venous pressure (CVP) and venous hepatic blood flow parameters. We further analyzed correlations between CVP and venous hepatic blood flow parameters. ⋯ Changes of central venous pressure due to changes of PEEP and positioning were not correlated with changes of venous hepatic blood flow parameters as measured after equilibration. Strategies aiming for low central venous pressure cannot be supported by these results. However, before ruling out low-CVP-strategies during liver resections these results should be confirmed by further studies.
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J Clin Monit Comput · Dec 2017
Phenylephrine increases near-infrared spectroscopy determined muscle oxygenation in men.
Phenylephrine increases mean arterial pressure (MAP) by enhanced total peripheral resistance (TPR) but near-infrared spectroscopy (NIRS) determined muscle oxygenation (SmO2) increases. We addressed that apparent paradox during supine rest and head-up tilt (HUT). Variables were determined ± phenylephrine in males during supine rest (n = 17) and 40° HUT (n = 7). ⋯ Brachial artery blood flow tended to decrease while SskinO2 together with StibialO2 decreased by 11% (P = 0.026) and 20% (P < 0.001), respectively. Conversely, phenylephrine increased SmO2 (9%) and restored the HUT elicited decrease in SmO2 (by 19%) along with SV (P = 0.02). Phenylephrine reduces skin and bone oxygenation and tends to reduce arm blood flow, suggesting that the increase in SmO2 reflects veno-constriction with consequent centralization of the blood volume.
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J Clin Monit Comput · Dec 2017
Observational StudyApplicability of stroke volume variation in patients of a general intensive care unit: a longitudinal observational study.
Sinus rhythm (SR) and controlled mechanical ventilation (CV) are mandatory for the applicability of respiratory changes of the arterial curve such as stroke volume variation (SVV) to predict fluid-responsiveness. Furthermore, several secondary limitations including tidal volumes <8 mL/kg and SVV-values within the "gray zone" of 9-13% impair prediction of fluid-responsiveness by SVV. Therefore, we investigated the prevalence of these four conditions in general ICU-patients. ⋯ In 9.7% (27/278) of the first measurements and in 12.8% (615/4801) of all measurements the patients did neither have SR nor CV. Only 20 of 278 (7.2%) of the first measurements and 8.2% of all measurements fulfilled both major criteria (CV, SR) and both minor criteria for the applicability of SVV. The applicability of SVV in ICU-patients is limited due to the absence of mandatory criteria during the majority of measurements.