| 1. |
- Amer-Wåhlin, I, et al.
(författare)
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Swedish randomized controlled trial of cardiotocography only versus cardiotocography plus ST analysis of fetal electrocardiogram revisited : analysis of data according to standard versus modified intention-to-treat principle.
- 2011
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Ingår i: Acta Obstetricia et Gynecologica Scandinavica. - : John Wiley & Sons Ltd.. - 0001-6349 .- 1600-0412. ; 90:9, s. 990-996
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To undertake a renewed analysis of data from the previously published Swedish randomized controlled trial on intrapartum fetal monitoring with cardiotocography (CTG-only) vs. CTG plus ST analysis of fetal electrocardiogram (CTG+ST), using current standards of intention-to-treat (ITT) analysis and to compare the results with those of the modified ITT (mITT) and per protocol analyses. METHODS: Renewed extraction of data from the original database including all cases randomized according to primary case allocation (n=5 049). MAIN OUTCOME MEASURE: Metabolic acidosis in umbilical artery at birth (pH <7.05, base deficit in extracellular fluid >12.0 mmol/l) including samples of umbilical vein blood or neonatal blood if umbilical artery blood was missing. RESULTS: The metabolic acidosis rates were 0.66% (17 of 2 565) and 1.33% (33 of 2 484) in the CTG+ST and CTG-only groups, respectively [relative risk (RR) 0.50; 95% confidence interval (CI) 0.28-0.88; p=0.019]. The original mITT gave RR 0.47, 95%CI 0.25-0.86 (p=0.015), mITT with correction for 10 previously misclassified cases RR 0.48, 95%CI 0.24-0.96 (p=0.038) and per protocol analysis RR 0.40, 95%CI 0.20-0.80 (p=0.009). The level of significance of the difference in metabolic acidosis rates between the two groups remained unchanged in all analyses. CONCLUSION: Re-analysis of data according to the ITT principle showed that regardless of the method of analysis, the Swedish randomized controlled trial maintained its ability to demonstrate a significant reduction in metabolic acidosis rate when using CTG+ST analysis for fetal surveillance in labor.
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| 2. |
- Kro, G A B, et al.
(författare)
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A new tool for the validation of umbilical cord acid-base data.
- 2010
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Ingår i: BJOG : an international journal of obstetrics and gynaecology. - : Wiley. - 1471-0528 .- 1470-0328. ; 117:12, s. 1544-52
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Tidskriftsartikel (refereegranskat)abstract
- To identify the distribution of carbon dioxide tension (pCO(2) ) relative to pH in validated umbilical cord acid-base data.
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| 3. |
- Kro, GA, et al.
(författare)
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Association between umbilical cord artery pCO₂ and the Apgar score; elevated levels of pCO₂ may be beneficial for neonatal vitality after moderate acidemia.
- 2013
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Ingår i: Acta Obstetricia et Gynecologica Scandinavica. - : John Wiley & Sons Ltd.. - 0001-6349 .- 1600-0412. ; 92:6, s. 662-70
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To determine the association between 5-min Apgar score and umbilical cord artery carbon dioxide tension (pCO₂). DESIGN: Observational study. SETTING: European hospital labor wards. POPULATION: Data from 36,432 newborns ≥36 gestational weeks were obtained from three sources: two trials of monitoring with fetal electrocardiogram (the Swedish randomized controlled trial and the European Union Fetal ECG trial) and Mölndal Hospital data. After validation of the acid-base values, 25,806 5-min Apgar scores were available for analysis. METHODS: Validation of the umbilical cord acid-base values was performed to obtain reliable data. 5-min Apgar score was regressed against cord artery pCO₂ in a polynomial multilevel model. MAIN OUTCOME MEASURES: Five-min Apgar score, umbilical cord pCO₂, pH, and base deficit. RESULTS: Overall, a higher cord artery pCO₂ was found to be associated with lower 5-min Apgar scores. However, among newborns with moderate acidemia, lower umbilical cord artery pCO₂ (≤median pCO₂ for the specific cord artery pH) was associated with lower 5-min Apgar scores, with a relative risk of 2.0 (95% confidence interval: 1.4-2.8) for 5-min Apgar scores 0-6. CONCLUSIONS: Metabolic acidosis affects the newborn's vitality more than respiratory acidosis. In addition, elevated levels of pCO₂ may be beneficial for fetuses with moderate acidemia, and thus cord artery pCO₂ is a factor that should be considered when assessing the compromised newborn.
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| 4. |
- Larsson, Peter, 1979-, et al.
(författare)
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Calculating carbon nanotube–catalyst adhesion strengths
- 2007
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - : American Physical Society. - 1098-0121 .- 1550-235X. ; 75:11
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Tidskriftsartikel (refereegranskat)abstract
- Density-functional theory is used to assess the validity of modeling metal clusters as single atoms or rings of atoms when determining adhesion strengths between clusters and single-walled carbon nanotubes (SWNTs). Representing a cluster by a single atom or ring gives the correct trends in SWNT-cluster adhesion strengths (Fe ≈ Co > Ni), but the single-atom model yields incorrect minimum-energy structures for all three metals. We have found that this is because of directional bonding between the SWNT end and the metal cluster, which is captured in the ring model but not by the single atom. Hence, pairwise potential models that do not describe directional bonding correctly, and which are commonly used to study these systems, are expected to give incorrect minimum-energy structures.
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| 5. |
- Nunes, I, et al.
(författare)
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Prolonged saltatory fetal heart rate pattern leading to newborn metabolic acidosis
- 2014
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Ingår i: Clinical and Experimental Obstetrics and Gynecology. - : I R O G Canada, Inc.. - 0390-6663. ; 41:5, s. 507-11
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The saltatory pattern, characterized by wide and rapid oscillations of the fetal heart rate (FHR), remains a controversial entity. The authors sought to evaluate whether it could be associated with an adverse fetal outcome. Material and Methods: The authors report a case series of four saltatory patterns occurring in the last 30 minutes before birth in association with cord artery metabolic acidosis, obtained from three large databases of internally acquired FHR tracings. The distinctive characteristics of this pattern were evaluated with the aid of a computer system. Results: All cases were recorded in uneventful pregnancies, with normal birth weight singletons, born vaginally at term. The saltatory pattern lasted between 23 and 44 minutes, exhibited a mean oscillatory amplitude of 45.9 to 80.0 beats per minute (bpm) and a frequency between four and eight cycles per minute. Conclusions: A saltatory pattern exceeding 20 minutes can be associated with the occurrence of fetal metabolic acidosis.
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