A Fluorescent Thin Film-Based Miniaturized Transcutaneous Carbon Dioxide Monitor

Measurements of transcutaneous carbon dioxide (tcCO2) have been used in multiple venues, such as during procedures utilizing jet ventilation, hyperbaric oxygen therapy, as well as both the adult and neo-natal ICUs. However, tcCO2 measurements have not been validated under conditions which utilize an artificial lung, such cardiopulmonary bypass (CPB). The purpose of this study was to (1) validate the use of tcCO2 using an artificial lung during CPB and (2) identify a location for the sensor that would optimize estimation of PaCO2 when compared to the gold standard of blood gas analysis. tcCO2 measurements ( N = 185) were collected every 30 min during 54 pulsatile CPB procedures. The agreement/differences between the tcCO2 and the PaCO2 were compared by three sensor locations. Compared to the earlobe or the forehead, the submandibular PtcCO2 values agreed best with the PaCO2 and with a median difference of –.03 mmHg (IQR = 5.4, p < 0.001). The small median difference and acceptable IQR support the validity of the tcCO2 measurement. The multiple linear regression model for predicting the agreement between the submandibular tcCO2 and PaCO2 included the SvO2, the oxygenator gas to blood flow ratio, and the native perfusion index ( R2 = 0.699, df = 1, 60; F = 19.1, p < 0.001). Our experience in utilizing tcCO2 during CPB has demonstrated accuracy in estimating PaCO2 when compared to the gold standard arterial blood gas analysis, even during CO2 flooding of the surgical field.

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Continuous, transcutaneous carbon-dioxide monitoring to avoid hypercapnia in complex catheter ablations under conscious sedation

European Heart Journal ◽

10.1093/ehjci/ehaa946.0448 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

K Weinmann ◽

A Lenz ◽

R Heudorfer ◽

D Aktolga ◽

M Rattka ◽

...

Keyword(s):

Carbon Dioxide ◽

Conscious Sedation ◽

Venous Blood ◽

Patient Comfort ◽

Carbon Dioxide Partial Pressure ◽

Close Monitoring ◽

Blood Gas ◽

Transcutaneous Carbon Dioxide ◽

The Difference ◽

Venous Blood Gas

Abstract Background Ablation of complex cardiac arrhythmias requires an immobilized patient. For a successful and safe intervention and for patient comfort, this can be achieved by conscious sedation. Administered sedatives and analgesics have respiratory depressant side effects and require close monitoring. Purpose We investigated the feasibility and accuracy of an additional, continuous transcutaneous carbon-dioxide partial pressure (tpCO2) measurement during conscious sedation in complex electrophysiological catheter ablation procedures. Methods We evaluated the accuracy and additional value of tpCO2 detection by application of a Severinghaus electrode in comparison to arterial and venous blood gas analyses. Results We included 110 patients in this prospective observational study. Arterial pCO2 (paCO2) and tpCO2 showed good correlation throughout the procedures (r=0.60–0.87, p<0.005). Venous pCO2 (pvCO2) were also well correlated to transcutaneous values (r=0.65–0.85, p<0.0001). Analyses of the difference of pvCO2 and tpCO2 measurements showed a tolerance within <10mmHg in up to 96–98% of patients. Hypercapnia (pCO2<70mmHg) was detected more likely and earlier by continuous tpCO2 monitoring compared to half-hourly pvCO2 measurements. Conclusion Continuous tpCO2 monitoring is feasible and precise with good correlation to arterial and venous blood gas carbon-dioxide analysis during complex catheter ablations under conscious sedation and may contribute to additional safety. Funding Acknowledgement Type of funding source: None

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Low-Fluence Laser Induced Fragmentation and Desorption of 3,4,9,10-Perylenetetracarboxylic Dianhydride (PTCDA) Thin Film

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.543.30 ◽

2013 ◽

Vol 543 ◽

pp. 30-34 ◽

Cited By ~ 2

Author(s):

Aljona Ramonova ◽

Tengiz Butkhuzi ◽

Viktorija Abaeva ◽

I.V. Tvauri ◽

Soslan Khubezhov ◽

...

Keyword(s):

Thin Film ◽

Carbon Dioxide ◽

Carbon Monoxide ◽

Kinetic Energy ◽

Atomic Oxygen ◽

Laser Light ◽

Pulsed Laser ◽

Molecular Fragmentation ◽

Irradiation Pulse ◽

Main Effect

Laser-induced fragmentation and desorption of fragments of PTCDA films vacuum-deposited on GaAs (100) substrate has been studied by time-of-flight (TOF) mass spectroscopy. The main effect caused by pulsed laser light irradiation (pulse duration: 10 ns, photon energy: 2.34 eV and laser fluence ranging from 0.5 to 7 mJ/cm2) is PTCDA molecular fragmentation and desorption of the fragments formed, whereas no desorption of intact PTCDA molecule was detected. Fragments formed are perylene core C20H8, its half C10H4, carbon dioxide, carbon monoxide and atomic oxygen. All desorbing fragments have essentially different kinetic energy. The mechanism of photoinduced molecular fragmentation and desorption is discussed.

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