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Venous Saturation (venous + saturation)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Predictors of Survival 1 Hour After Implantation of an Intra-aortic Balloon Pump in Cardiac Surgery

JOURNAL OF CARDIAC SURGERY, Issue 1 2001
Harald Hausmann M.D.
From July 1996 to March 2000, 391 patients with intraoperative cardiac lowoutput syndrome who underwent surgery with heart-lung bypass and had an intre-aortic balloon pump (IABP) Implanted were analyzed in a prospective study. Of these 391 patients, 153 (39%) were operated on in an emergency situation, and 238 (61%) patients had elective surgeries. The perioperative mortality was 34% (133 patients). Clinical parameters were analyzed 1 hour after IABP support began. Statistical multivariate analysis showed that patients with an adrenaline requirement higher than 0.5 ,g/kg/min, a left mrial pressure higher then 15 mmHg, output of less than 100 mL/hour, and mixed venous saturation (SvO2) of less then 60% had poor outcomes. Using this data, we developed an IABP score to predict survival early after IABP implantation in cardiac surgery. We conclude that the success or failure of perioperative IABP support can be predicted early after implantation of the balloon pump. In patients with low-output syndrome despite IABP support, implantation of a vantricular assist system should be considered. [source]

Haemodynamic changes during positive-pressure ventilation in children

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2005
A. Kardos
Background:, Positive-pressure ventilation may alter cardiac function. Our objective was to determine with the use of impedance cardiography (ICG) whether altering airway pressure modifies the central haemodynamics in mechanically ventilated children with no pulmonary pathology. Central venous saturation (ScvO2) was measured as an indicator of tissue perfusion. Methods:, Twelve children between 7 and 65 months of age, requiring mechanical ventilation as a consequence of a non-pulmonary disease, were enrolled in the study. All patients had a central venous line as a part of their routine management. Using pressure controlled ventilation (PCV) the baseline PEEP value of 5 cmH2O (Pb5) was increased to 10 cmH2O (Pi10) and then to 15 cmH2O (Pi15). After Pi15, PEEP was decreased to 10 (Pd10) and then to 5 cmH2O (Pd5). Each time period lasted 5 min heart rate (HR), mean arterial blood pressure (MABP), central venous pressure (CVP), end-tidal carbon dioxide (ETCO2), mean airway pressure (Paw), stroke volume index (SVI), cardiac index (CI) and central venous oxygen saturation (ScvO2) were recorded at the end of the five periods. Results:, The values of CI did not change when 10 and 15 cmH2O of PEEP were applied. Elevation of PEEP and thus Paw caused slight but not significant reductions in SVI and ScvO2 as compared to the baseline (Tb5). After reducing PEEP in Td5 we found statistically significant elevations of SVI and CI, as compared to Ti15 heart rate, ETCO2 and MABP remained unchanged. Conclusion:, We did not find significant haemodynamic changes following PEEP elevation in ventilated children, as measured using impedance cardiography. Reducing the value of PEEP to 5 cmH2O resulted in statistically significant SVI elevations. The values of ScvO2 remained unaffected. [source]

2321: Retinal vessel diameter affects oxygen saturation measurements

ACTA OPHTHALMOLOGICA, Issue 2010
SH HARDARSON
Purpose To test whether retinal vessel oxygen saturation measurements are affected by vessel diameter and to compare saturation between the temporal and nasal retina. Methods The Oxymap retinal oximeter is based on a fundus camera. It measures light absorbance at two wavelengths of light and calculates oxygen saturation in retinal vessels as well as vessel diameter. Measurements were performed on 12 healthy individuals. The effect of vessel diameter on saturation measurements was tested by measuring before and after the first bifurcation in the retina (1st degree parent vessels and 2nd degree daughter vessels). Arteriolar saturation can be assumed to be equal before and after bifurcation. Results The ratio between oxygen saturation in 1st degree parent arteriole and 2nd degree daughter arteriole was 0.97±0.02 (mean±SD). The ratio was significantly lower than the theoretical value of 1.00 (p<0.001, n=12) The corresponding ratio for venules was 0.90±0.04 (p<0.001). Oxygen saturation was 94±6% in 1st degree superotemporal arterioles and 99±6% in superonasal arterioles (p=0.057). Oxygen saturation in inferotemporal arterioles was 89±6% and 95±4% in inferonasal arterioles (p=0.009). There was no significant difference in venous saturation between temporal and nasal quadrants. Conclusion Measured oxygen saturation is lower in 1st degree parent vessels than in their 2nd degree daughter branches. This indicates that retinal vessel diameter affects oxygen saturation measurements. The higher measured saturation in the nasal arterioles, compared to temporal arterioles, may also be due to the fact that the nasal vessels are narrower. A correction for the effect of vessel diameter should be incorporated into oxygen saturation measurements. Commercial interest [source]

Retinal vessel oximetry using sequential and 'snapshot' hyperspectral imaging

ACTA OPHTHALMOLOGICA, Issue 2009
A MCNAUGHT
Purpose Use of sequential, and 'snapshot' hyperspectral imagers to measure oxygen saturation in retinal vessels in normals, and examples of eye disease, eg glaucoma, and retinovascular diseases. Validation of estimated oximetry values using a model eye. Methods A sequential hyperspectral imager was constructed using a fundus camera with built-in liquid-crystal tuneable filter. Images of normals,and ocular disease are presented. A novel 'snapshot' hyperspectral imager is also described: this produces images in a single exposure. Validation of both devices using an artificial eye with capillary tubes containing human blood of known oxygen saturation, placed in front of an 'artificial retina' is described. The image analysis used to detect retinal vessels, and generate oximetric values is detailed. Results Both the sequential, and 'snapshot' retinal imagers produced accurate estimations of retinal vessel oxygen saturation, when compared with the model eye. Imaging of a small group of glaucoma eyes showed abnormally elevated venous oxygen saturation. In proliferative diabetic retinopathy, abnormally elevated venular saturation was found in areas of capillary loss on FFA. In vein occlusion, elevated venous saturation was found in eyes with ischaemic FFAs. Conclusion Both the sequential and 'snapshot' hyperspectral imagers deliver useful oximetric maps of the retina. The 'snapshot' device allows more rapid imaging. The elevated venular oxygen saturation seen in both glaucoma, and retinovascular disease, is perhaps evidence of reduced oxygen consumption in damaged inner retina in glaucoma, and/or vascular 'shunting' in retinovascular disease. [source]