0000000000039711
AUTHOR
Kimiko Fukui
Hemodynamic Parameters Change Earlier Than Tissue Oxygen Tension in Hemorrhage
BACKGROUND: Untreated hypovolemia results in impaired outcome. This study tests our hypothesis whether general hemodynamic parameters detect acute blood loss earlier than monitoring parameters of regional tissue beds. MATERIALS AND METHODS: Eight pigs (23-25 kg) were anesthetized and mechanically ventilated. A pulmonary artery catheter and an arterial catheter were inserted. Tissue oxygen tension was measured with Clark-type electrodes in the jejunal and colonic wall, in the liver, and subcutaneously. Jejunal microcirculation was assessed by laser Doppler flowmetry (LDF). Intravascular volume was optimized using difference in pulse pressure (dPP) to keep dPP below 13%. Sixty minutes after p…
Relationship Between Regional Cerebral Blood Flow and Electrocorticographic Activities Under Sevoflurane and Isoflurane Anesthesia
The aims of this study are (1) to assess the effects of volatile anesthetics on regional cerebral blood flow (rCBF) and electrocorticography (ECoG), and (2) to investigate the relationship between rCBF and ECoG influenced by volatile anesthetics. The authors measured rCBF using laser Doppler flowmetry and ECoG simultaneously and continuously from the same cortex during craniotomy, using the specially arranged probe. Patients received intravenous anesthetics with nitrous oxide until craniotomy, and after opening of dura, volatile anesthetic, either isoflurane or sevoflurane, was started and was gradually increased for the measurement. Four of the nine cases (44.4%) of the sevoflurane group s…
Measurement of Cortical Microcirculation During Intracranial Aneurysm Surgery by Combined Laser-Doppler Flowmetry and Photospectrometry
Accidental vessel occlusion is one major risk of intracranial aneurysm surgery potentially causing cerebral ischemia. The intraoperative assessment of cerebral ischemia remains a technological challenge.As a novel approach, cortical tissue integrity was monitored using simultaneous measurements of regional capillary-venous cerebral blood flow (rvCBF), oxygen saturation (Srvo2), and hemoglobin amount (rvHb) during aneurysm surgery.Fifteen patients scheduled for aneurysm surgery of the anterior and posterior circulation were included. A fiber optic probe was placed on the cortex associated with the distal branch of the aneurysmatic vessel. Blinded measurements by combined laser-Doppler flowme…
Human cerebral microcirculation and oxygen saturation during propofol-induced reduction of bispectral index †
† This study investigates the effects of propofol-induced changes in bispectral index (BIS) on cerebral microcirculation and oxygenation during craniotomies. † In 2 mm cerebral depth, an increase in propofol dosage resulted in increased oxygen saturation (srvO2 )w ithout reduction of capillary venous blood flow (rvCBF). † Difference in oxygen content (avDO2) and approximated cerebralmetabolicrateofoxygen (aCMRO2) decreased with an increase in propofol dosage in 2 mm cerebral depth. † Alterations in BIS showed no effect on rvCBF, srvO2 ,a nd haemoglobin amount (rvHb) or on avDO2 or aCMRO2 in 8 mm cerebral depth. † These findings suggest that the CBF/CMRO2 ratio is altered by propofol in a re…
Automatic algorithm for monitoring systolic pressure variation and difference in pulse pressure.
BACKGROUND: Difference in pulse pressure (dPP) reliably predicts fluid responsiveness in patients. We have developed a respiratory variation (RV) monitoring device (RV monitor), which continuously records both airway pressure and arterial blood pressure (ABP). We compared the RV monitor measurements with manual dPP measurements. METHODS: ABP and airway pressure (PAW) from 24 patients were recorded. Data were fed to the RV monitor to calculate dPP and systolic pressure variation in two different ways: (a) considering both ABP and PAW (RV algorithm) and (b) ABP only (RV(slim) algorithm). Additionally, ABP and PAW were recorded intraoperatively in 10-min intervals for later calculation of dPP …