Changes in middle cerebral artery and cerebral regional oxygen saturation (rSO2) by Valsava manoeuvre in supine, sitting and standing position: Study in healthy volunteers

2011 ◽  
Vol 28 ◽  
pp. 69
Author(s):  
F. J. Tercero ◽  
I. Gracia ◽  
G. Pastor ◽  
R. Valero ◽  
N. De Riva ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Middle Cerebral Artery ◽  
Healthy Volunteers ◽  
Cerebral Artery ◽  
Standing Position ◽  
Regional Oxygen Saturation

Effects of different ventilation on cerebral oxygen saturation and cerebral blood flow before and after modified ultrafiltration in infants during ventricular septal defect repair

2021 ◽  
pp. 1-6
Author(s):  
Boqun Cui ◽  
Chuan Ou-Yang ◽  
Siyuan Xie ◽  
Duomao Lin ◽  
Jun Ma
Keyword(s):  
Oxygen Saturation ◽  
Middle Cerebral Artery ◽  
Flow Velocity ◽  
Cerebral Artery ◽  
Septal Defect ◽  
Cerebral Oxygen Saturation ◽  
Cerebral Oxygen ◽  
Regional Cerebral Oxygen Saturation ◽  
Defect Repair ◽  
Artery Flow

Abstract Objective: To analyse the changes of different ventilation on regional cerebral oxygen saturation and cerebral blood flow in infants during ventricular septal defect repair. Methods: Ninety-two infants younger than 1 year were enrolled in the study. End-expiratory tidal pressure of carbon dioxide was maintained at 40–45 and 35–39 mmHg in relative low and high ventilation groups. Regional cerebral oxygen saturation and flow velocity of the middle cerebral artery were recorded after anaesthesia (T0), cut pericardium (T1), separation from cardiopulmonary bypass (T2), the end of modified ultrafiltration, (T3) and at the end of operation (T4). Results: The relative low ventilation group exhibited a significantly high regional cerebral oxygen saturation at each time point except for T2 (T0:77 ± 4, T1:76 ± 5, T3:76 ± 8, T4:76 ± 8, respectively, p < 0.001). Flow velocity of the middle cerebral artery in the relative low ventilation group was higher compared to the relative high ventilation group at each time point except for T2 (T0:53 ± 14, T1:54 ± 15, T3:53 ± 17, T4:52 ± 16, respectively, p < 0.001). Between the two groups, T2 showed the lowest middle cerebral artery flow velocity (relative low ventilation: 39 ± 15, relative high ventilation: 39 ± 11, p < 0.001). Conclusion: The infants’ regional cerebral oxygen saturation and middle cerebral artery flow velocity performed better in the range of 40–45 mmHg end-expiratory tidal pressure of carbon dioxide during CHD surgery. Modified ultrafiltration increased cerebral oxygen saturation. It was important to regulate ventilation in order to balance cerebral oxygen in infants.

scholarly journals Cerebral autoregulation and symptoms of orthostatic hypotension in familial dysautonomia

2016 ◽  
Vol 37 (7) ◽  
pp. 2414-2422 ◽  
Author(s):  
Cristina Fuente Mora ◽  
Jose-Alberto Palma ◽  
Horacio Kaufmann ◽  
Lucy Norcliffe-Kaufmann
Keyword(s):  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Area Under The Curve ◽  
Standing Position ◽  
Familial Dysautonomia ◽  
Cerebrovascular Resistance ◽  
Dicrotic Notch ◽  
Baroreflex Failure ◽  
Measured Flow ◽  
Orthostatic Symptoms

Familial dysautonomia is an inherited autonomic disorder with afferent baroreflex failure. We questioned why despite low blood pressure standing, surprisingly few familial dysautonomia patients complain of symptomatic hypotension or have syncope. Using transcranial Doppler ultrasonography of the middle cerebral artery, we measured flow velocity (mean, peak systolic, and diastolic), area under the curve, pulsatility index, and height of the dictrotic notch in 25 patients with familial dysautonomia and 15 controls. In patients, changing from sitting to a standing position, decreased BP from 124 ± 4/64 ± 3 to 82 ± 3/37 ± 2 mmHg (p < 0.0001, for both). Despite low BP, all patients denied orthostatic symptoms. Middle cerebral artery velocity fell minimally, and the magnitude of the reductions were similar to those observed in healthy controls, in whom BP upright did not fall. While standing, patients had a greater fall in cerebrovascular resistance (p < 0.0001), an increase in pulsatility (p < 0.0001), and a deepening of the dicrotic notch (p = 0.0010), findings all consistent with low cerebrovascular resistance. No significant changes occurred in controls. Patients born with baroreflex deafferentation retain the ability to buffer wide fluctuations in BP and auto-regulate cerebral blood flow. This explains how they can tolerate extremely low BPs standing that would otherwise induce syncope.

Middle cerebral artery blood velocity during a Valsalva maneuver in the standing position

2000 ◽  
Vol 88 (5) ◽  
pp. 1545-1550 ◽  
Author(s):  
Frank Pott ◽  
Johannes J. van Lieshout ◽  
Kojiro Ide ◽  
Per Madsen ◽  
Niels H. Secher
Keyword(s):  
Cardiac Output ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Valsalva Maneuver ◽  
Venous Pressure ◽  
Standing Position ◽  
Blood Velocity ◽  
Central Venous ◽  
Mouth Pressure ◽  
The Brain

Occasionally, lifting of a heavy weight leads to dizziness and even to fainting, suggesting that, especially in the standing position, expiratory straining compromises cerebral perfusion. In 10 subjects, the middle cerebral artery mean blood velocity ( V mean) was evaluated during a Valsalva maneuver (mouth pressure 40 mmHg for 15 s) both in the supine and in the standing position. During standing, cardiac output decreased by 16 ± 4 (SE) % ( P < 0.05), and at the level of the brain mean arterial pressure (MAP) decreased from 89 ± 2 to 78 ± 3 mmHg ( P < 0.05), as did V mean from 73 ± 4 to 62 ± 5 cm/s ( P < 0.05). In both postures, the Valsalva maneuver increased central venous pressure by ∼40 mmHg with a nadir in MAP and cardiac output that was most pronounced during standing (MAP: 65 ± 6 vs. 87 ± 3 mmHg; cardiac output: 37 ± 3 vs. 57 ± 4% of the resting value; P < 0.05). Also, V mean was lowest during the standing Valsalva maneuver (39 ± 5 vs. 47 ± 4 cm/s; P < 0.05). In healthy individuals, orthostasis induces an ∼15% reduction in middle cerebral artery V mean that is exaggerated by a Valsalva maneuver performed with 40-mmHg mouth pressure to ∼50% of supine rest.

Magnetic Resonance Angiography Shows Dilatation of the Middle Cerebral Artery after Infusion of Glyceryl Trinitrate in Healthy Volunteers

Cephalalgia ◽  
2007 ◽  
Vol 27 (2) ◽  
pp. 118-127 ◽  
Author(s):  
JM Hansen ◽  
DL Pedersen ◽  
VA Larsen ◽  
M Sánchez-del-Rio ◽  
JR Alvarez Linera ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Angiography ◽  
Glyceryl Trinitrate ◽  
Middle Cerebral Artery ◽  
Healthy Volunteers ◽  
Cerebral Artery ◽  
Observer Variation ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional

Previous studies have reported dilatation of the middle cerebral artery (MCA) during acute glyceryl trinitrate (GTN)-induced headache, using imaging techniques such as transcranial Doppler (TCD), positron emission tomography (PET) and single photon emission computerized tomography (SPECT). In the present study we aimed to evaluate whether magnetic resonance angiography (MRA) may be used to examine the effect of GTN on the MCA, with respect to changes in diameter and cross-sectional area in healthy volunteers. In addition, we wanted to determine the intra- and inter-observer variation of the method. In a randomized, double blind, crossover study 12 healthy volunteers received intravenous infusion of GTN (0.5 μg/kg/min for 20 min) or placebo. Using 1.5 Tesla MRA, we recorded changes in the diameter and cross-sectional area of MCA before, during and after infusion of GTN. The MRA images were evaluated by two blinded, independent observers/neuroradiologists. The primary endpoints were the differences in the AUC for diameter and cross-sectional area of the MCA between the two experimental conditions and the intra- and inter-observer variation. The areas under the curve (AUC) of the MCA diameter and cross-sectional area were significantly greater after GTN than after placebo ( P < 0.05). The intra-observer variation (day-to-day) at baseline was 8.3% and 10.9% for the two observers. The mean inter-observer variation of the cross-sectional MCA area was 15.5% and for the diameter measurements 8%. The present study shows that the MRA method gives a reliable semi-quantitative index of the vascular changes in the intra-cerebral arteries after infusion of GTN and may be useful for headache research.

A Novel Hyperspectral Imaging System for Intraoperative Prediction of Cerebral Hyperperfusion Syndrome after Superficial Temporal Artery-Middle Cerebral Artery Anastomosis in Patients with Moyamoya Disease

2021 ◽  
Vol 50 (2) ◽  
pp. 208-215
Author(s):  
Katsuma Iwaki ◽  
Soh Takagishi ◽  
Koichi Arimura ◽  
Masaharu Murata ◽  
Toru Chiba ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Oxygen Saturation ◽  
Middle Cerebral Artery ◽  
Hyperspectral Imaging ◽  
Moyamoya Disease ◽  
Cerebral Artery ◽  
Superficial Temporal Artery ◽  
Temporal Artery ◽  
Cerebral Hyperperfusion Syndrome ◽  
Cerebral Hyperperfusion

Background: Postoperative cerebral hyperperfusion syndrome (CHS) may occur after superficial temporal artery (STA)-middle cerebral artery (MCA) bypass for moyamoya disease (MMD). Predicting postoperative CHS is challenging; however, we previously reported the feasibility of using a hyperspectral camera (HSC) for monitoring intraoperative changes in brain surface hemodynamics during STA-MCA bypass. Objective: To investigate the utility of HSC to predict postoperative CHS during STA-MCA bypass for patients with MMD. Methods: Hyperspectral images of the cerebral cortex of 29 patients with MMD who underwent STA-MCA bypass were acquired by using an HSC before and after anastomosis. We then analyzed the changes in oxygen saturation after anastomosis and assessed its correlation with CHS. Results: Five patients experienced transient neurological deterioration several days after surgery. 123I-N-Isopropyl-iodoamphetamine single-photon emission computed tomography scan results revealed an intense, focal increase in cerebral blood flow at the site of anastomosis without any cerebral infarction. Patients with CHS showed significantly increased oxygen saturation (SO2) in the cerebral cortex after anastomosis relative to those without CHS (33 ± 28 vs. 8 ± 14%, p < 0.0001). Receiver operating characteristic analysis results show that postoperative CHS likely occurs when the increase rate of cortical SO2 value is >15% (sensitivity, 85.0%; specificity, 81.3%; area under curve, 0.871). Conclusions: This study indicates that hyperspectral imaging of the cerebral cortex may be used to predict postoperative CHS in patients with MMD undergoing STA-MCA bypass.

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