ABSTRACT
Sixty-three patients were intraoperatively examined during heart surgery with extracorporeal circulation (AEC). They were operated on for an affected heart-valve apparatus (AHVA) and ischemic heart disease (IHD). There was a perioperative monitoring of central hemodynamics, pressure in the bulb of superior jugular vein (BSJV) and electroencephalography (EEG). Regional oxygenation of the brain was made in real time by a INVOS3100 oximeter (SOMANETICS, USA). A maximal saturation of the cortex blood with oxygen at AEC was registered in patients with AHVA at an average pressure below 70 mm Hg, and in patients with IHD--at 85 mm Hg. An increased pressure in BSJV at a constant mean arterial pressure and at AEC is related with blood outflow from the venous collector of the brain.
Subject(s)
Cardiac Surgical Procedures , Cerebral Cortex/blood supply , Extracorporeal Circulation , Hemodynamics/physiology , Oxygen/blood , Blood Gas Monitoring, Transcutaneous , Cerebral Cortex/metabolism , Female , Humans , Male , Middle Aged , Monitoring, IntraoperativeABSTRACT
The time course of changes in rSO2 were studied in 58 patients during the uncomplicated course of cardiac operations under extracorporeal circulation (EC) and moderate hypothermia. rSO2 was also compared with central hemodynamic parameters, bioelectrical cerebral activity, and hemoglobin oxygen saturation of the bulb of the internal jugular vein (jbSO2). In the pre- and postperfusion period there was a significant correlation of rSO2 and jbSO2 (p = 0.01), yet with a low correlation coefficient (r = 0.348). During EC, no correlation was found between rSO2 and jbSO2 (p = 0.09, r = 0.386). Changes in rSO2, blood pressure, EEC, body temperature were analyzed in 2 groups of patients at the stages of an operation under EC. Group 1 comprised patients with cardiac valvular apparatus lesions and Group 2 included those with coronary heart disease who differed not only in age, but also in the history of mainly cerebrovascular atherosclerotic lesions, hypertensive disease, myocardial infarction, etc. In patients from both groups, a reduction in rSO2 occurred at the beginning of EC and at the maximum of cooling. But if in Group 1 patients, the significant reductions in rSO2 at the beginning of EC coincided both with that in mean blood pressure (BPmean), as compared to the baseline values (from 75.55 +/- 10.68 to 66.5 +/- 11.73 mm Hg, p = 0.01), and with the change in the frequency spectrum of EEC (a decrease in the frequency of the right edge, as compared to the baseline values, from 20.77 +/- 1.44 to 19.58 +/- 1.14 Hz, p = 0.01), in Group 2 patients, all significant decreases in rSO2 were accompanied only by a significant reduction in BPmean, but without changes in the frequency spectrum of EEG. It should be noted that over the uncomplicated course of an operation all changes in rSO2 were in the normal range of age-related values.
Subject(s)
Brain/blood supply , Cardiac Surgical Procedures/methods , Extracorporeal Circulation , Oximetry/methods , Oxygen/blood , Adult , Anesthesia, General , Female , Humans , Male , Middle Aged , Monitoring, Intraoperative , Oximetry/instrumentationABSTRACT
Intraoperative monitoring of cerebral ischemia during surgery on the brachiocephalic arteries is carried out by several methods: transcranial dopplerography, electroencephalography, recording of the somatosensory evoked potentials, puncture measurement of intravascular pressure, etc. However, not all these methods are sufficiently informative, reliable, and safe. One of the methods meeting these requirements is noninvasive cerebral oximetry. The study was carried out by the Invos-3100 device (Somanetics, USA). The method of cerebral oximetry is based on optic spectroscopy using infrared light in the 650-1100 nm waveband. Monitoring was carried out in 34 patients with involvement of the brachiocephalic arteries. The results persuasively prove high informative value and safety of the method.
