scholarly journals Effect of Transcutaneous Electrode Temperature on Accuracy and Precision of Carbon Dioxide and Oxygen Measurements in the Preterm Infants

2018 ◽  
Vol 63 (7) ◽  
pp. 900-906 ◽  
Author(s):  
Jessica F Jakubowicz ◽  
Shasha Bai ◽  
David N Matlock ◽  
Michelle L Jones ◽  
Zhuopei Hu ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Preterm Infants ◽  
Electrode Temperature ◽  
Accuracy And Precision ◽  
Oxygen Measurements

scholarly journals Carbon dioxide levels in neonates: what are safe parameters?

2021 ◽  
Author(s):  
Sie Kei Wong ◽  
M. Chim ◽  
J. Allen ◽  
A. Butler ◽  
J. Tyrrell ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Systematic Review ◽  
Side Effects ◽  
Preterm Infants ◽  
Periventricular Leukomalacia ◽  
List Type ◽  
Permissive Hypercapnia ◽  
Prisma Statement ◽  
Carbon Dioxide Levels ◽  
Online Software

Abstract There is no consensus on the optimal pCO2 levels in the newborn. We reviewed the effects of hypercapnia and hypocapnia and existing carbon dioxide thresholds in neonates. A systematic review was conducted in accordance with the PRISMA statement and MOOSE guidelines. Two hundred and ninety-nine studies were screened and 37 studies included. Covidence online software was employed to streamline relevant articles. Hypocapnia was associated with predominantly neurological side effects while hypercapnia was linked with neurological, respiratory and gastrointestinal outcomes and Retinpathy of prematurity (ROP). Permissive hypercapnia did not decrease periventricular leukomalacia (PVL), ROP, hydrocephalus or air leaks. As safe pCO2 ranges were not explicitly concluded in the studies chosen, it was indirectly extrapolated with reference to pCO2 levels that were found to increase the risk of neonatal disease. Although PaCO2 ranges were reported from 2.6 to 8.7 kPa (19.5–64.3 mmHg) in both term and preterm infants, there are little data on the safety of these ranges. For permissive hypercapnia, parameters described for bronchopulmonary dysplasia (BPD; PaCO2 6.0–7.3 kPa: 45.0–54.8 mmHg) and congenital diaphragmatic hernia (CDH; PaCO2 ≤ 8.7 kPa: ≤65.3 mmHg) were identified. Contradictory findings on the effectiveness of permissive hypercapnia highlight the need for further data on appropriate CO2 parameters and correlation with outcomes. Impact There is no consensus on the optimal pCO2 levels in the newborn. There is no consensus on the effectiveness of permissive hypercapnia in neonates. A safe range of pCO2 of 5–7 kPa was inferred following systematic review.

Effect of CO2 and 100% O2 on cerebral blood flow in preterm infants

1980 ◽  
Vol 48 (3) ◽  
pp. 468-472 ◽  
Author(s):  
F. A. Leahy ◽  
D. Cates ◽  
M. MacCallum ◽  
H. Rigatto
Keyword(s):  
Carbon Dioxide ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Preterm Infants ◽  
Cerebral Circulation ◽  
Pressure Change ◽  
Venous Occlusion ◽  
Co2 Sensitivity ◽  
Important Regulator ◽  
Carbon Dioxide Pressure

To determine 1) the effect of arterial CO2 change on the neonatal cerebral circulation and 2) whether 100% O2 would produce significant decrease in cerebral blood flow (CBF), we studied 24 preterm infants to explain the late (5 min) hyperventilation observed in them during hyperoxia. Of these, 12 were studied before and during inhalation of 2-3% CO2 and 12 before and during the inhalation of 100% O2. We measured CBF by a modification of the venous occlusion plethysmography technique and found that CBF increased 7.8% per Torr alveolar carbon dioxide pressure change and that it decreased 15% with 100% O2. These findings suggest that 1) CO2 is an important regulator of CBF in the perterm infant, 2) CBF-CO2 sensitivity in these infants may be greater than in adult subjects, 3) 100% O2 reduced CBF significantly, and 4) a decrease in CBF during administration of 100% O2 may be at least partially responsible for the increase in ventilation with hyperoxia.

scholarly journals Using airborne HIAPER Pole-to-Pole Observations (HIPPO) to evaluate model and remote sensing estimates of atmospheric carbon dioxide

2016 ◽  
Author(s):  
C. Frankenberg ◽  
S. S. Kulawik ◽  
S. Wofsy ◽  
F. Chevallier ◽  
B. Daube ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
Correlation Coefficients ◽  
Added Value ◽  
Total Carbon ◽  
Accuracy And Precision ◽  
Atmospheric Carbon ◽  
Carbon Dioxide Co2 ◽  
Global Carbon ◽  
Comparable Quality

Abstract. In recent years, space-borne observations of atmospheric carbon-dioxide (CO2) have become increasingly used in global carbon-cycle studies. In order to obtain added value from space-borne measurements, they have to suffice stringent accuracy and precision requirements, with the latter being less crucial as it can be reduced by just enhanced sample size. Validation of CO2 column averaged dry air mole fractions (XCO2) heavily relies on measurements of the Total Carbon Column Observing Network TCCON. Owing to the sparseness of the network and the requirements imposed on space-based measurements, independent additional validation is highly valuable. Here, we use observations from the HIAPER Pole-to-Pole Observations (HIPPO) flights from January 2009 through September 2011 to validate CO2 measurements from satellites (GOSAT, TES, AIRS) and atmospheric inversion models (CarbonTracker CT2013B, MACC v13r1). We find that the atmospheric models capture the XCO2 variability observed in HIPPO flights very well, with correlation coefficients (r2) of 0.93 and 0.95 for CT2013B and MACC, respectively. Some larger discrepancies can be observed in profile comparisons at higher latitudes, esp. at 300 hPa during the peaks of either carbon uptake or release. These deviations can be up to 4 ppm and hint at misrepresentation of vertical transport. Comparisons with the GOSAT satellite are of comparable quality, with an r2 of 0.85, a mean bias μ of −0.06 ppm and a standard deviation σ of 0.45 ppm. TES exhibits an r2 of 0.75, μ of 0.34 ppm and σ of 1.13 ppm. For AIRS, we find an r2 of 0.37, μ of 1.11 ppm and σ of 1.46 ppm, with latitude-dependent biases. For these comparisons at least 6, 20 and 50 atmospheric soundings have been averaged for GOSAT, TES and AIRS, respectively. Overall, we find that GOSAT soundings over the remote pacific ocean mostly meet the stringent accuracy requirements of about 0.5 ppm for space-based CO2 observations.

IMPROVE ON PERFORMANCE OF INDIRECT CALORIMETRY FOR SMALL PRETERM INFANTS

2001 ◽  
Vol 13 (03) ◽  
pp. 109-115 ◽  
Author(s):  
SHIH-CHING LIN ◽  
CHING-HSING LUO ◽  
TSU-FUH YEH
Keyword(s):  
Oxygen Consumption ◽  
Energy Consumption ◽  
Clinical Research ◽  
Preterm Infants ◽  
Indirect Calorimetry ◽  
Carbon Dioxide Production ◽  
Laboratory Evaluation ◽  
Low Birth Weight Infants ◽  
Accuracy And Precision ◽  
Improved Performance

An indirect calorimetry system of measuring oxygen consumption and carbon dioxide production has been frequently used for preterm infants. The energy consumption and metabolic measurements are based on flow-through technology. The noninvasive measurement feature of the indirect calorimeter is widely used in pediatric clinical research. However, the indirect calorimeter has several limitations for small preterm infants, particularly the ill infant weighing < 1.0 kg. In this paper, we propose some technologies and methodologies to improve the performance of the indirect calorimetry. According to these technologies and methodologies, we redesign the indirect calorimeter proposed in our pervious study. The laboratory evaluation at the different alcohol combustion rates and several exhaust flow rates is used to survey the improved performance. As the results, the accuracy and precision is enhanced by these methods and the lowest oxygen consumption rate, 4.35 ml/min, fits for baby weight of 0.66 kg. It is demonstrated that the performances of new indirect calorimetry are substantially improved. It can be applied to calculate the energy consumption and metabolic rate for low-birth-weight infants in clinical research.

scholarly journals 60 Correlation of Carbon Dioxide Levels as Measured by Arterial, Transcutaneous and End Tidal Methods in Preterm Infants <28 Weeks Gestation

2004 ◽  
Vol 9 (suppl_a) ◽  
pp. 37A-37A
Author(s):  
L Aliwalas ◽  
L Noble ◽  
K Nesbitt ◽  
S Fallah ◽  
V Shah ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Preterm Infants ◽  
Carbon Dioxide Levels ◽  
End Tidal

Oxygen measurements in the root zone facilitated by TDR

2000 ◽  
Vol 80 (1) ◽  
pp. 33-41 ◽  
Author(s):  
G.C. Topp ◽  
B. Dow ◽  
M. Edwards ◽  
E. G. Gregorich ◽  
W. E. Curnoe ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Plant Growth ◽  
Crop Yields ◽  
Root Zone ◽  
Soil Surface ◽  
Carbon Dioxide Flux ◽  
No Till ◽  
Oxygen Measurement ◽  
Oxygen Measurements ◽  
Temperature Water

Deleterious soil structural conditions, as from compaction, can reduce plant growth and yields by reducing aeration and oxygen in the rooting environment. Using a double-membrane oxygen cathode in each of four corn plots, we measured soil oxygen concentrations in duplicate at depths of 5, 10, 20 and 30 cm during the growing season. In addition, temperature, water content and bulk density determinations allowed the monitoring of O2 concentration trends under no-till and conventional-till corn management. Carbon dioxide flux from the soil surface was measured weekly. Temporal patterns of O2 levels fluctuated in response to rainfall at all depths but much less so at 30-cm depth. At 30 cm the O2 concentration remained inadequate for optimum plant growth (<0.01 kg m−3) for over 2 mo after planting under no-till with poorly timed trafficking. Under conventional till and appropriately timed trafficking adequate aeration occurred more than a month earlier than under no-till. The CO2 output was generally lower by 10 to 30% in no-till than that in conventional till, indicating measurably lower levels of biological activity. The relative magnitudes of mid-season O2 concentrations and CO2 flux densities showed the same pattern as the crop yields for all tillage treatments. More analyses of seasonal O2 consumption patterns are required to determine if lack of O2 is a causal factor for the reduced crop yield. Key words: TDR, aeration, oxygen measurement, carbon dioxide, tillage, root zone

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