The effect of cerebral oximeter use on the shunt placement concerning carotid endarterectomy surgery

Background: During carotid arterial endarterectomy (CAE) surgery, an intraluminal shunt is used to prevent hypoperfusion, which can be caused by a cross-clamping cerebral ischemia. However, routine shunt use is not recommended. Various cerebral monitoring techniques are used to determine the need for shunt placement. In this study, retrospective analysis of data on the efficacy of cerebral oximetry in the decision of shunt use during elective CAE surveys was planned. Materials and Methods: We collected data on 68 patients operated under general anesthesia between December 2016 and December 2017. Patients were evaluated for near infrared spectrometry (NIRS) and stump pressure values and whether shunt was placed or not. Results: Eight (11.7%) patients were shunting. NIRS value after cross-clamping was lower in patients with shunt. Stump pressure values were below 40 mmHg. Conclusions: Cerebral monitoring in elective CAE operations has great importance in determining the necessity of using intraluminal shunt to reduce the complications that may occur.

Effect of muscle relaxation on the oxygenation of human skeletal muscle: a prospective in-vivo experiment using an isolated forearm technique / 대한마취과학회지

BACKGROUND: Total oxygen consumption has been found to be reduced under deep neuromuscular blockade due to a lower rate of metabolism of skeletal muscles. However, the magnitude of this effect in individual muscles has not been investigated. Thus the aim of this study was to compare the oxygenation of paralyzed versus non-paralyzed forearm muscle under tourniquet-provoked ischemia. METHODS: After ethics approval and written informed consent, 30 patients scheduled for elective hand and wrist surgery were included. Ischemia was provoked by inflation of bilateral upper arm tourniquets and muscle relaxation was achieved via intravenous administration of rocuronium 0.9 mg/kg. Bilateral tourniquets were applied to both upper arms before induction of anesthesia and near infrared spectrometry (NIRS) electrodes applied on both forearms. Muscular ischemia in an isolated (= non-paralyzed, NP) as well as a paralyzed forearm (P) was created by sequential inflation of both tourniquets before and after intravenous administration of rocuronium. Muscle oxygen saturations (SmO2) of NIRS in both forearms and their changes were determined and compared. RESULTS: Data of 30 patients (15 male, 15 female; 41.8 +/- 14.7 years) were analyzed. The speed of SmO2 decrease (50% decrease of SmO2 from baseline (median [percentiles]: NP 210 s [180/480s] vs. P 180 [180/300]) as well as the maximum decrease in SmO2 (minimum SmO2 in % (median [percentiles]: NP 20 [19/24] vs. P 21 [19/28]) were not significantly affected by neuromuscular paralysis. CONCLUSIONS: No significant effect of muscle relaxation on NIRS-assessed muscle oxygenation under tourniquet-induced ischemia was found in human forearm muscles.

Difference Analysis and Optimization Study for Determination of Fructose and Glucose by Near Infrared Spectroscopy / 分析化学

A total of 101 honey samples that originated from 20 different unifloral honey and other multifloral honey samples were collected from China.FT-NIR spectrometer were applied to determinate the content of fructose and glucose of honey with two different modes: transflectance (800-2500 nm, 2 mm optical path length) and transmittance (800-1370 nm, 20 mm optical path length).It was found that the prediction accuracy of fructose and glucose had significant difference with the two modes.In order to analyze the reason of this difference, support vector machine (SVM) was used to analyze the non-linear information, and genetic algorithm (GA) was used to analyze the characteristic wavelengths.The result indicated that the detection difference of fructose and glucose was originated from their different characteristic wavelengths.Through the optimization of detection method, it was found that for the determination of glucose, short wavelength and long optical path length should be used, on the other side, the whole wavelength region and short wavelength, with selecting the characteristic wavelength to avoid the disturb of water can also be used.For the determination of fructose, whole wavelength region and short optical path length should be used.Linear regression methods such as PLSR could obtain good results, and non-linear methods such as SVM did not improve the model performance.

Changes in blood pressure, heart rate and regional cerebral oxygen saturation during the sitting position for shoulder arthroscopic surgery / 대한마취과학회지

BACKGROUND: The sitting position for shoulder arthroscopic surgery can cause critical hypotension, a reduction in cerebral blood flow and possible cerebral ischemia due to decreased venous return.The aim of this study was to determine the effects of a positional change to the sitting position on the mean arterial pressure (MAP), heart rate (HR) and regional cerebral oxygen saturation (rSO2) through ECG, invasive blood pressure monitoring and near-infrared spectrometry. METHODS: Thirty five patients of ASA class I or II undergoing shoulder surgery were chosen randomly.General anesthesia was administered with sevoflurane and a mixed gas of medical air and oxygen.The MAP, HR, rSO2 and rate of change in the rSO2 on the left and right side were measured at the following times:after induction when the MAP and HR were stabilized (baseline), 1, 3, 5, 10, 15 and 20 min after placing the patient in the sitting position. RESULTS: The MAP decreased significantly at 5, 10, 15 and 20 min after placing the patient in the sitting position.The HR increased significantly at 1 min and 3 min after placing the patient in the sitting position, and decreased significantly at 15 min and 20 min after placing the patient in the sitting position.The rSO2 showed a significant decrease at 5, 10, 15 and 20 min on the left side and at 10 min, 15 min and 20 min on the right side. CONCLUSIONS: The MAP and rSO2 significantly decreased after placing the patient in the sitting position but there were no neurological complications.However, close monitoring of the MAP and rSO2 is required in elderly patients or patients with cerebrovascular disease is recommended while the patient is in the sitting position in order to avoid neurological complications.