An in Vitro Assessment of a Monitor for Continuous Inline Measurement of PO2, PCO2 and pH during Cardiopulmonary Bypass

Perfusion ◽  
1987 ◽  
Vol 2 (2) ◽  
pp. 139-147 ◽  
Author(s):  
R Peter Alston ◽  
Arthur Trew
Keyword(s):  
Cardiopulmonary Bypass ◽  
In Vitro Model ◽  
Blood Gas Analysis ◽  
Systematic Errors ◽  
Gas Analysis ◽  
Blood Gas ◽  
In Vitro Assessment ◽  
Vitro Model ◽  
Inline Measurement

The Gas STAT is a monitor which continuously measures PO2. PCO2 and pH inline during cardiopulmonary bypass. Using an in vitro model, the monitor's accuracy was compared to standard blood gas analysis over a range of PO2 (2·0–66·7 kPa), PCO2 (2·7–12·0 kPa) and pH (7–8). Its stability as affected by time, temperature, flow and haematocrit and the presence of halothane, enflurane, isoflurane and sodium nitroprusside was examined. Good correlations were found between the monitor and standard blood gas analysis for PO2 (r = 0·999, P < 0·001) and PCO2 (r = 0·996, P < 0·001). However, large and unpredictable systematic errors occurred. It was stable under all conditions examined, except that in one sensor there was a statistically significant decline in PCO2 measurement with time (P < 0·005) and the PCO2 readings were affected by temperature (P < 0·021). The monitor provides useful information for blood gas management during cardiopulmonary bypass, but should not be used without recourse to standard blood gas analysis.

Validation of transcutaneous carbon dioxide monitoring using an artificial lung during adult pulsatile cardiopulmonary bypass

2021 ◽  
pp. 039139882098785
Author(s):  
Lawrence Garrison ◽  
Jeffrey B Riley ◽  
Steve Wysocki ◽  
Jennifer Souai ◽  
Hali Julick
Keyword(s):  
Carbon Dioxide ◽  
Cardiopulmonary Bypass ◽  
Gold Standard ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Artificial Lung ◽  
Blood Gas ◽  
Median Difference ◽  
Transcutaneous Carbon Dioxide ◽  
Arterial Blood

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.

scholarly journals In vitro assessment of the starch digestibility of western Canadian wheat market classes and cultivars

2018 ◽  
Vol 98 (3) ◽  
pp. 463-476 ◽  
Author(s):  
Namalika D. Karunaratne ◽  
Dawn A. Abbott ◽  
Ravindra N. Chibbar ◽  
Pierre J. Hucl ◽  
Curtis J. Pozniak ◽  
...  
Keyword(s):  
Crude Protein ◽  
In Vitro Model ◽  
Starch Digestibility ◽  
Wheat Market ◽  
In Vitro Assessment ◽  
Market Class ◽  
Small Intestinal ◽  
Vitro Model ◽  
Total Starch

The objective of the study was to measure the effect of wheat market class and cultivar on starch digestibility using an in vitro model that mimics the chicken digestive tract and relate it to grain characteristics. The study evaluated 18 wheat cultivars from eight western Canadian wheat classes and, each cultivar was replicated four times. Samples were subjected to gastric and small intestine (SI) digestion phases and each sample was assayed in triplicate; glucose release was measured in SI phase. Starch granule distribution, amylose, total starch, crude protein (CP), ash, and non-starch polysaccharides (NSP) were analyzed in all wheat samples. Small intestinal phase times of 15, 60, and 120 min were chosen to approximate digestion in the terminal duodenum, jejunum, and ileum. Starch digestibility of wheat classes ranged as follows: 15 min — 33.1% to 49.1%, 60 min — 80.2% to 93.3%, and 120 min — 92.4% to 97.6%. Starch digestibility positively correlated with CP, ash, NSP, and proportion of large granules, whereas it negatively correlated with total starch, and proportion of small and medium granules. In conclusion, market class and cultivar of western Canadian wheat affects both rate and extent of starch digestibility and it is related to various grain characteristics.

scholarly journals A Comparative Study on Oxygenating Capacity of Terumo Pediatric Oxygenator vs Dideco Pediatric Oxygenator

2004 ◽  
Vol 3 (3) ◽  
pp. 60
Author(s):  
SN Chaudhary ◽  
M Ghatta ◽  
U Khan
Keyword(s):  
Comparative Analysis ◽  
Cardiopulmonary Bypass ◽  
Comparative Study ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Data Sheet ◽  
Blood Gas ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Arterial Blood Gas Analysis

This study shows the comparative analysis on oxygenating capacity of two brands of oxygenators: DIDECO Midiflow D705 and TERUMO Capiox 5X10. This study is based on the arterial blood gas analysis which was done during cardiopulmonary bypass. The data was obtained from perfusion data sheet available at SGNHCG. 71 DIDECO and 55 TERUMO oxygenators and altogether 335 arterial blood gas samples were considered for the study.

An in vitro study of the effects of isoflurane on oxygen transfer

Perfusion ◽  
2001 ◽  
Vol 16 (4) ◽  
pp. 293-299 ◽  
Author(s):  
Michelle L Muhle ◽  
Alfred H Stammers ◽  
Kimberly D Tremain ◽  
Kevin S Niimi ◽  
Kimberly R Glogowski ◽  
...  
Keyword(s):  
Oxygen Transfer ◽  
Gas Flow ◽  
In Vitro Study ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Anesthetic Technique ◽  
Vitro Model ◽  
The Given

A common anesthetic technique utilized during cardiopulmonary bypass (CPB) includes the use of various inhalation agents, such as isoflurane. The purpose of this study was to evaluate the effects of this agent on oxygen transfer during CPB. An in vitro model was designed using bovine blood. Blood flow was held constant at 2 l/min, while gas flow was manipulated at 1 and 3 l/min. The percentage of inspired oxygen (FiO2) was set at 50 and 100%, and isoflurane was manipulated to 1.0, 3.0 and 5.0%. Blood gas analysis, oxygen transfer, and inlet and outlet isoflurane concentrations were measured at each of the given conditions. A total of 12 trials with four oxygenators were conducted. In the four oxygenators used in our study, no significant differences in oxygenator performance were found. At conditions of 1 l/min gas flow, 50% FiO2 and 1% isoflurane, there were no significant changes in O2 transfer between baseline and measurements taken during isoflurane administration (100.18 ± 12.49 vs 102.35 ± 10.99 ml O2/min, p=0.8031). At 3 l/min gas flow, 100% FiO2 and 5% isoflurane, no significant differences were found (142.35 ± 10.76 vs 154.04 ± 8.95 ml O2/min, p=0.1459). The only significant differences found for oxygen transfer were between 50 and 100% FiO2, all other conditions being set equal (102.35 ± 10.99 vs 137.68 ± 8.62 ml O2/min, p=0.0023). In conclusion, increasing concentrations of isoflurane up to 5% does not affect the efficiency of oxygen transfer in an in vitro circuit. Further studies are necessary to evaluate the effects in an in vivo setting.

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