Preliminary Results on Direct Measurement of Regional Myocardial Oxygenation during Coronary Stenosis and Hemodilution in Dogs

Klövekorn, W. P.; Schabert, A.; Kessler, M

doi:10.1159/000402240

Cited by 3 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The reduced hematocrit of 33% at baseline can be attributed to the infusion of Ringer's solution according to the experimental protocol because the animals have been slightly anemic (Hot 38%) already prior to anesthesia. Unfortunately, with one exception [21] authors measuring myocardial PtO2 did not report at which hematocrit the control PtO2 histograms were obtained [28,32] or failed to report hematocrit values at all [36,42,43,53,54,58,59,60]. Moderate isovolemic hemodilution down to a hematocrit of 28%, as carried out in this study, is in the range of perioperative hemodilution accepted under clinical conditions [44].…”

Section: Effect Of Hemodilutionmentioning

confidence: 79%

See 1 more Smart Citation

Right ventricular tissue PO2 in dogs

Forst¹,

Racenberg²,

Schosser

et al. 1987

Res. Exp. Med.

View full text Add to dashboard Cite

Right ventricular (RV) epicardial tissue oxygen pressure (PtO2) was measured polarographically by means of a platinum multiwire surface electrode on the in situ beating heart of ten anesthetized dogs prior to and after moderate (Hct 28%) normovolemic hemodilution (HD) with dextran 60. In five dogs the effect of acute occlusion of the right coronary artery (RCA) on PtO2 was analyzed. The PtO2 histograms at baseline revealed a bell-shaped configuration and a mean PtO2 of 46.2 +/- 7.1 mm Hg which coincides with the PtO2 on the left ventricle (LV) reported by others. After HD mean PtO2 increased to 51.4 +/- 8.5 mm Hg (P = 0.02) without alterations of the histogram's configuration. Hemodynamics and blood gas analyses were unchanged after HD. RCA ligature was followed by non-uniform changes in the PtO2 pattern. Thus, despite marked differences in external work and O2 consumption, the PtO2 in both RV and LV myocardium are similar at rest. The increase of PtO2 in the RV at reduced Hct values, which is not seen in the LV myocardium, can be related to differences in functional capillary density between both ventricles.

show abstract

Section: Effect Of Hemodilutionmentioning

confidence: 79%

“…Patients with limited coronary reserve should not undergo hemodilution since it has been shown in animal models [15,31,32,49] that coronary reserve can be exhausted at moderately reduced hematocrit values. Left ventricular PtO2 was found unchanged or reduced as a result of hemodilution [28,30,32].…”

Section: Effect Of Hemodilutionmentioning

confidence: 99%

Right ventricular tissue PO2 in dogs

Forst¹,

Racenberg²,

Schosser

et al. 1987

Res. Exp. Med.

View full text Add to dashboard Cite

show abstract

“…However, the development in the 1970s of highly flexible optical fibers and their incorporation into bundles 33,34 meant that noninvasive spectrophotometric measurements, using a broadband source and resolved at multiple wavelengths, could be carried out in the reflectance mode, and even in moving organs. 35 Other methods such as pulse oximetry 36 employ the simpler, less costly options of using light emitting-and photo-diodes to transmit and receive light at a few selected wavelengths. Alternatively, discrete wavelength laser diodes can be used as light sources, transmitted via optical fibers and received via optical fibers and photo-diodes.…”

Section: Measurements Of Hemoglobin Oxygen Saturation In Tissuementioning

confidence: 99%

Optical Measurement of Tissue Oxygen Saturation

Harrison

2002

The International Journal of Lower Extremity Wounds

View full text Add to dashboard Cite

Advances in opto-electronic systems have meant that optical spectroscopy can now be used for noninvasive measurements in tissue in patients. A number of techniques have evolved over the last 15 years that make use of the characteristic differences in the absorption spectrum of deoxygenated and oxygenated hemoglobin to measure oxygen saturation. This article summarizes, in particular, those techniques that may prove to be applicable to measurements relating to lower extremity wounds. A short introduction is given about existing electrode methods before describing applications of near infrared and visible wavelength spectroscopy to measurements in tissue. The advantages and limitations of these methods are discussed. An example of an area where tissue spectroscopy is now in routine clinical use for tissue healing viability assessment is presented.

show abstract

Myocardial oxygenation and transmural lactate metabolism during experimental acute coronary stenosis in pigs

Gonschior

Conzen

et al. 1992

Basic Res Cardiol

View full text Add to dashboard Cite

Measurement of surface tissue pO2 (ptO2) with surface electrodes is increasingly applied in experimental medicine. Its use on the beating heart may seem to be problematic because transmural gradients of tissue pO2 would reduce the validity of pO2 determinations in the epicardial layers. This study attempted to determine whether ptO2 may be a valid and sensitive indicator of transmural myocardial oxygenation. In order to measure ptO2, two eight-channel Clark-type electrodes were placed on a beating porcine left ventricle (n = 13). Measurements were made at different degrees of acute stenosis of the left anterior descending artery (LAD). A 24-F cannula was inserted into the great cardiac vein, draining the poststenotic myocardium to obtain coronary venous blood samples. Transmural metabolic changes were detected simultaneously by coronary venous blood gas parameters and lactate levels. Epicardial tissue pO2 was 49 +/- 2 mm Hg (mean +/- SEM) before stenosis and decreased to a mean value of 25 +/- 2 mm Hg during stenosis. Different degrees of LAD stenosis (ptO2 range: 12-35 mm Hg) were substantial enough to alter arterio-coronary venous lactate difference (avd lactate) from +0.31 +/- 0.07 mmol/l (control) to -0.62 +/- 0.15 mmol/l (stenosis). A significant linear correlation between changes of ptO2 (delta ptO2) and changes of avd lactate (delta avd lactate) resulted (y = 0.59 + 0.62x; r = 0.86; p less than or equal to 0.001). However, linear regression analysis between delta ptO2 correlated with the corresponding data from coronary venous pO2 (delta pO2cv) oxygen content (delta O2contcv), and oxygen saturation (delta O2satcv) showed no significant correlations. We conclude that measurement of ptO2 is a sensitive and valuable indicator of transmural oxygenation in ischemic myocardium, whereas pO2cv, O2contcv and O2satcv do not seem to be valid predictors of ischemia in myocardial oxygenation.

show abstract

Preliminary Results on Direct Measurement of Regional Myocardial Oxygenation during Coronary Stenosis and Hemodilution in Dogs

Cited by 3 publications

References 0 publications

Right ventricular tissue PO2 in dogs

Right ventricular tissue PO2 in dogs

Optical Measurement of Tissue Oxygen Saturation

Myocardial oxygenation and transmural lactate metabolism during experimental acute coronary stenosis in pigs

Contact Info

Product

Resources

About