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

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.

Author(s):  
Mia Kahvo ◽  
Ajit Mahaveer ◽  
Ranganath Ranganna

Objective: To assess agreement between transcutaneous carbon dioxide (TcCO2) monitoring and blood gas analysis in neonates. Study Design: This was a prospective observational study performed in a tertiary neonatal intensive care unit. 19 infants with a mean postmenstrual age of 35+3 weeks were included. Agreement was assessed by Bland-Altman analysis and concordance correlation coefficient. End-user feedback was collected from staff and infants were assessed for evidence of skin damage. Results: Overall bias from 698 paired samples was -0.30 (SD 1.21, p<0.0001) with good concordance (CCC 0.80). 69% (95% CI 65%-72%, p=0.0003) of samples fell within the predefined clinically acceptable difference of 1kPa. Agreement was more favorable for non-invasively ventilated infants (bias -0.11, CCC 0.91). Staff feedback was positive, and no infants suffered skin damage. Conclusion: TcCO2 monitoring is a reliable assessment tool for both invasively and non-invasively ventilated neonates. It can be used as an adjunct to blood gas analysis, reducing the frequency of invasive blood tests.


2004 ◽  
Vol 3 (3) ◽  
pp. 60
Author(s):  
SN Chaudhary ◽  
M Ghatta ◽  
U Khan

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.


2017 ◽  
Vol 21 (2) ◽  
pp. 76-80
Author(s):  
Thuthi Mohan ◽  
B Vinodh Kumar

ABSTRACT Introduction Measured total carbon dioxide (TCO2) from venous sample and calculated bicarbonate from arterial blood gas (ABG) have shown good agreement in some studies, while conflicting results have been obtained in few other studies. The objective of this study is to compare and assess the degree of agreement between the measured TCO2 and calculated bicarbonate and also whether they can be used interchangeably in our laboratory. Materials and methods We prospectively analyzed 89 ABG samples requested for calculated bicarbonate and then measured TCO2 from venous blood samples drawn simultaneously from the same participants between November 2016 and April 2017. Results Measured TCO2 results ranged from 5.7 to 39.9 mmol/L (mean 23.45 mmol/L), while calculated bicarbonate ranged from 9 to 40 mmol/L (mean 24.36 mmol/L). The values of TCO2 and bicarbonate correlated well (r = 0.95, p < 0.001), with the correlation given by the equation, y = 0.884x + 3.605. The bias obtained was —0.9 mmol/L and the standard deviation (SD) was 1.62 mmol/L. The limits of agreement (LOA) were —4.1 to 2.3 mmol/L, with a span of 6.4 mmol/L. Out of the 89 values, 85 (95.05%) were within the LOA. Conclusion In majority of the cases, the calculated bicarbonate concentration from ABG showed a good correlation to the measured venous TCO2 concentration. Despite this excellent correlation, TCO2 did not show good agreement with calculated bicarbonate when Story and Poustie's criteria were applied, especially in cases of bicarbonate less than 20 mmol/L. Hence, clinicians should be aware of this discrepancy and be cautious when using measured TCO2 and calculated bicarbonate interchangeably in the assessment and management of acid—base disorders, especially in patients with metabolic acidosis. How to cite this article Mohan T, Kumar BV. Comparison of measured Serum Total Carbon Dioxide with calculated Bicarbonate calculated from Arterial Blood Gas Analysis. Indian J Med Biochem 2017;21(2):76-80.


2016 ◽  
Vol 68 (6) ◽  
pp. 1395-1402
Author(s):  
P.E.S. Silva ◽  
N. Nunes ◽  
A.P. Gering ◽  
T.C. Prada ◽  
A.P.R. Simões ◽  
...  

ABSTRACT The aim of this study was to evaluate the effect of epidural bupivacaine administration at the first lumbar vertebra on cardiopulmonary variables, arterial blood gases and anti-nociception. Sixteen healthy female dogs were randomly assigned into two groups based on bupivacaine dose: G1 group, 1mg kg-1 or G2 group, 2mg kg-1, diluted in the same final volume (1mL4kg-1). Cardiopulmonary variables were measured and arterial blood gas was collected (T0), it was repeated 10 minutes after intravenous administration of butorphanol 0.4mg kg -1 (T1). Anesthesia was induced with intravenous etomidate at 2mg kg-1 and the epidural catheter was introduced and placed at the first lumbar vertebra. Thirty minutes later, bupivacaine was administered epidurally. Cardiopulmonary measurements and arterial blood gas analysis were recorded at 10 minute intervals (T2 to T6). Evaluation of pre surgical anti-nociception was performed at 5 minute intervals for 30 minutes by clamping the hind limbs, anus, vulva, and tail with the dogs awake. Subsequently, ovariohysterectomy was performed and adequacy of surgical anti-nociception was evaluated at 5 time points. Parametric data were analyzed using the F test with a <0.05 significance. After bupivacaine administration, there were differences between groups just for bicarbonate means (HCO3 -) on T6 (P=0.0198), with 18.7±1.3 and 20.4±0.8 for G1 and G2, respectively. After T1, before bupivacaine administration, both groups presented a slightly lower pH, base excess (BE), the end-tidal carbon dioxide tension (PECO2), and partial pressure of carbon dioxide (PaCO2), suggesting mild metabolic acidosis. G2 showed better antinociceptive effect both before and during surgery. It was possible to perform ovariohysterectomy in 87.5% of the G2 bitches and 25% of the G1 bitches. The two doses of bupivacaine evaluated do not cause important alterations in the studied parameters and the dose of 2mg kg-1 results in a better antinociceptive effect.


Perfusion ◽  
2006 ◽  
Vol 21 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Frode Kristiansen ◽  
Jan Olav Høgetveit ◽  
Thore H Pedersen

This paper presents the clinical testing of a new capno-graph designed to measure the carbon dioxide tension at the oxygenator exhaust outlet in cardiopulmonary bypass (CPB). During CPB, there is a need for reliable, accurate and instant estimates of the arterial blood CO2 tension (PaCO2) in the patient. Currently, the standard practice for measuring PaCO2 involves the manual collection of intermittent blood samples, followed by a separate analysis performed by a blood gas analyser. Probes for inline blood gas measurement exist, but they are expensive and, thus, unsuitable for routine use. A well-known method is to measure PexCO2, ie, the partial pressure of CO2 in the exhaust gas output from the oxygenator and use this as an indirect estimate for PaCO2. Based on a commercially available CO2 sensor circuit board, a laminar flow capnograph was developed. A standard sample line with integrated water trap was connected to the oxygenator exhaust port. Fifty patients were divided into six different groups with respect to oxygenator type and temperature range. Both arterial and venous blood gas samples were drawn from the CPB circuit at various temperatures. Alfa-stat corrected pCO2 values were obtained by running a linear regression for each group based on the arterial temperature and then correcting the PexCO2 accordingly. The accuracy of the six groups was found to be (±SD): ±4.3, ±4.8, ±5.7, ±1.0, ±3.7 and ±2.1%. These results suggest that oxygenator exhaust capnography is a simple, inexpensive and reliable method of estimating the PaCO2 in both adult and pediatric patients at all relevant temperatures.


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