Artificial Circulation Effect on Oxygen Saturation in the Brain Phantom
Olga Nikona,
Roberts Leibuss,
Rihards Starinskis,
Davis Starinskis,
Davis Mackevics,
Yuri Dekhtyar,
Vlads Vulkanovs,
Eva Strike
Issue:
Volume 9, Issue 2, March 2023
Pages:
9-16
Received:
30 September 2022
Accepted:
24 October 2022
Published:
25 May 2023
Abstract: Cardiovascular surgery represents a field where the anesthetist frequently deals with quickly evolving conditions associated with anesthesia, perfusion, and the scope of surgery, that have a direct and indirect impact on the oxygen delivery to organs and tissues and its consumption ratio. The prospects of predicting the oxygen concentration influential factors on the brain create a possibility for effective decisions in the crucial moments of cardiac surgery during a cardiopulmonary bypass, to choose specific neuroprotection to decrease postoperative neurologic complication risk. Nowadays, near-infrared spectroscopy (NIRS) technology has been used to perform cerebral oximetry analysis. By reviewing available literature, the work on the possible dependence of artificial blood circulation on oxygen concentration in the brain is provided. This research aims to investigate how artificial circulation, specifically the flow and viscosity of the fluid equivalent to blood, affects oxygen concentration in the cerebral phantom. The thesis contains methodology for measuring the concentration of oxygen was considered, as well as the manufacture of a phantom of the brain and an equivalent blood fluid. The results illustrate that the artificial blood flow rate has a non-linear effect on the oxygen concentration in the brain phantom. This was confirmed through the value of the oxygen concentration in the brain phantom under conditions of artificial blood circulation rSO2avg.= 85% with laminar flow and the value of rSO2avg.= 78% with turbulent flow. Additionally, it was proven that as the viscosity of the blood-equivalent fluid increases, the oxygen concentration decreases almost linearly. The calculated average rSO2 value at minimum viscosity η=2.0 mPa∙s and flow rate Q=0.5 l/min has maximum rSO2avg.=85%, while at maximum viscosity η=4.2 mPa∙s, rSO2 average value was the smallest rSO2avg.=72%. The study demonstrates that the type and rate of flow, as well as viscosity of the cardiopulmonary bypass, affect the measurements of oxygen concentration in the brain phantom.
Abstract: Cardiovascular surgery represents a field where the anesthetist frequently deals with quickly evolving conditions associated with anesthesia, perfusion, and the scope of surgery, that have a direct and indirect impact on the oxygen delivery to organs and tissues and its consumption ratio. The prospects of predicting the oxygen concentration influen...
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Percutaneous Intramyocardial Septal Radiofrequency Ablation in Patients with Hypertrophic Cardiomyopathy –A Systematic Review and Meta-Analysis
Fatema Tashrifwala,
Manisha Purushotham,
Sai Krishna Bhushan
Issue:
Volume 9, Issue 2, March 2023
Pages:
17-21
Received:
8 February 2023
Accepted:
25 February 2023
Published:
29 May 2023
Abstract: In this study, we aimed to meta-analyze all available data to provide a holistic, well-powered assessment of the effect of PIMSRA on LVOT gradient, LVEF, and anterior and posterior IVS thickness. PubMed, Cochrane Central, Embase, and Scopus were systematically searched from inception till October 2022 for published clinical trials assessing the efficacy of PIMSRA in patients with HCM using the keywords “PIMSRA” OR “Percutaneous Intramyocardial Septal Radiofrequency Ablation” OR “Liwen procedure. All five studies reported a change in LVOT gradient from the baseline. Integrated analysis showed no significant change from baseline (MD: -69.506; 95% CI: -77.047, -61.966; P = 0.089) (I² = 50.4%). Subgroup analyses based on follow-up revealed that there was no significant difference noted at 6 months according to data from 2 studies (MD: -65.351; 95% CI; -85.253, -45.450; P = 0.181) (I²= 44.1%) however data from 3 studies at one year follow up did reveal a significant difference from baseline (MD: -71.010; 95% CI: -80.262, -61.758; P = 0.047) (I² = 67.2%). Only three studies reported changes in LVEF from the baseline. This single-arm meta-analysis of 284 patients gathered from 5 clinical trials suggested that overall, after PIMSRA, LVOT gradient was reduced, and LVEF was slightly decreased. Additionally, no significant changes were observed in the anterior and posterior IVS thicknesses.
Abstract: In this study, we aimed to meta-analyze all available data to provide a holistic, well-powered assessment of the effect of PIMSRA on LVOT gradient, LVEF, and anterior and posterior IVS thickness. PubMed, Cochrane Central, Embase, and Scopus were systematically searched from inception till October 2022 for published clinical trials assessing the eff...
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