Breath-to-breath variability of exhaled CO2 as a marker of lung dysmaturity in infancy

2017 ◽  
Vol 123 (6) ◽  
pp. 1563-1570 ◽  
Author(s):  
Sotirios Fouzas ◽  
Ilias Theodorakopoulos ◽  
Edgar Delgado-Eckert ◽  
Philipp Latzin ◽  
Urs Frey
Keyword(s):  
Lung Disease ◽  
Preterm Infants ◽  
Chronic Lung Disease ◽  
Tidal Breathing ◽  
Term Infants ◽  
Young Infants ◽  
Postmenstrual Age ◽  
Preterm Group ◽  
Preterm Born ◽  
The Relationship

The concept of diffusional screening implies that breath-to-breath variations in CO2 clearance, when related to the variability of breathing, may contain information on the quality and utilization of the available alveolar surface. We explored the validity of the above hypothesis in a cohort of young infants of comparable postmenstrual age but born at different stages of lung maturity, namely, in term-born infants ( n = 128), preterm-born infants without chronic lung disease of infancy (CLDI; n = 53), and preterm infants with moderate/severe CLDI ( n = 87). Exhaled CO2 volume (VE,CO2) and concentration (FE,CO2) were determined by volumetric capnography, whereas their variance was assessed by linear and nonlinear variability metrics. The relationship between relative breath-to-breath change of VE,CO2 (ΔVE,CO2) and the corresponding change of tidal volume (ΔVT) was also analyzed. Nonlinear FE,CO2 variability was lower in CLDI compared with term and non-CLDI preterm group ( P < 0.001 for both comparisons). In CLDI infants, most of the VE,CO2 variability was attributed to the variability of VT ( r2 = 0.749), whereas in term and healthy preterm infants this relationship was weaker ( r2 = 0.507 and 0.630, respectively). The ΔVE,CO2 − ΔVT slope was less steep in the CLDI group (1.06 ± 0.07) compared with non-CLDI preterm (1.16 ± 0.07; P < 0.001) and term infants (1.20 ± 0.10; P < 0.001), suggesting that the more dysmature the infant lung, the less efficiently it eliminates CO2 under tidal breathing conditions. We conclude that the temporal variation of CO2 clearance may be related to the degree of lung dysmaturity in early infancy. NEW & NOTEWORTHY Young infants exhibit appreciable breath-to-breath CO2 variability that can be quantified by nonlinear variability metrics and may reflect the degree of lung dysmaturity. In infants with moderate/severe chronic lung disease of infancy (CLDI), the variability of the exhaled CO2 is mainly driven by the variability of breathing, whereas in term-born and healthy preterm infants this relationship is less strong. The slope of the relative CO2-to-volume change is less steep in CLDI infants, suggesting that dysmature lungs are less efficient in eliminating CO2 under tidal breathing conditions.

Hypoxemic and hyperoxemic likelihood in pulse oximetry ranges: NICU observational study

2018 ◽  
Vol 104 (3) ◽  
pp. F274-F279 ◽  
Author(s):  
Thomas E Bachman ◽  
Christopher J L Newth ◽  
Narayan P Iyer ◽  
Patrick A Ross ◽  
Robinder G Khemani
Keyword(s):  
Intensive Care Unit ◽  
Mechanical Ventilation ◽  
Intensive Care ◽  
Observational Study ◽  
Preterm Infants ◽  
Neonatal Intensive Care ◽  
Tertiary Care ◽  
Term Infants ◽  
Postmenstrual Age ◽  
Preterm Group

ObjectiveDescribe the likelihood of hypoxemia and hyperoxemia across ranges of oxygen saturation (SpO2), during mechanical ventilation with supplemental oxygenation.DesignRetrospective observational study.SettingUniversity affiliated tertiary care neonatal intensive care unit.PatientsTwo groups of neonates based on postmenstrual age (PMA): <32 weeks (n=104) and >36 weeks (n=709).Main measuresHypoxemia was defined as a PaO2 <40 mm Hg, hyperoxemia as a PaO2 of >99 mm Hg and normoxemia as a PaO2 of 50–80 mm Hg. Twenty-five per cent was defined as marked likelihood of hypoxemia or hyperoxemia.ResultsFrom these infants, 18 034 SpO2–PaO2 pairs were evaluated of which 10% were preterm. The PMA (median and IQR) of the two groups were: 28 weeks (27–30) and 40 weeks (38–41). With SpO2 levels between 90% and 95%, the likelihoods of hypoxemia and hyperoxemia were low and balanced. With increasing levels of SpO2, the likelihood of hyperoxemia increased. It became marked in the preterm group when SpO2 was 99%–100% (95% CI 29% to 41%) and in the term group with SpO2 levels of 96%–98% (95% CI 29% to 32%). The likelihood of hypoxemia increased as SpO2 decreased. It became marked in both with SpO2 levels of 80%–85% (95% CI 20% to 31%, 24% to 28%, respectively).ConclusionsThe likelihood of a PaO2 <40 mm Hg is marked with SpO2 below 86%. The likelihood of a PaO2 >99 mm Hg is marked in term infants with SpO2 above 95% and above 98% in preterm infants. SpO2 levels between 90% and 95% are appropriate targets for term and preterm infants.

scholarly journals 737. The Prevalence of Diagnosed Chronic Lung Disease in US Infants by Gestational Age: Implications for RSV Policy

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S264-S265 ◽  
Author(s):  
Christopher S Ambrose ◽  
Xiaohui Jiang ◽  
Kunjana Mavunda
Keyword(s):  
United States ◽  
Lung Disease ◽  
Gestational Age ◽  
Chronic Lung Disease ◽  
The United States ◽  
Supplemental Oxygen ◽  
High Risk Group ◽  
Term Infants ◽  
Postmenstrual Age ◽  
Nationally Representative

Abstract Background Perinatal chronic lung disease (CLD), previously referred to as bronchopulmonary dysplasia (BPD), is associated with preterm birth and occurs rarely among term infants. Children with CLD are at elevated risk for severe RSV disease in the first 2 years of life. Definitions of CLD/BPD identify infants who require supplemental oxygen at 28 days of life or 36 weeks postmenstrual age, with no restriction by gestational age (GA) at birth. However, the AAP Committee on Infectious Disease guidance does not recommend RSV immunoprophylaxis for infants with CLD born at ≥32 weeks gestational age (wGA), even though infants with CLD/BPD up to 41 wGA were included in pivotal efficacy studies. This study determined the prevalence of diagnosed CLD in US infants as a function of wGA at birth and the number of infants with CLD born at ≥32 wGA. Methods The Kids’ Inpatient Database (KID) is a nationally representative survey conducted every 3 years in the United States. Birth hospitalization data from KID were utilized to estimate the prevalence of CLD (ICD-9 = 770.7) among US infants in 2003–2012 overall and as a function of coincident codes for GA (ICD-9 = 765.21–765.29, reported in 2-week intervals). The prevalence of CLD among 32 wGA infants was imputed based on the distribution of CLD cases as a function of wGA. KID data from 2015 were not available due to the transition to ICD-10 coding. Results A total of 31,984 infants had a CLD diagnosis across the 4 years, representing 0.2% of US births. The prevalence of CLD declined from 20.8 to 19.5 per 10,000 between 2003 and 2012. Of those, 25,554 infants with CLD (80%) had GA coded in the database. The percentage of CLD infants born at &lt;27 wGA increased from 44% in 2003 to 52% in 2012, whereas the percentage at ≥29 wGA decreased from 27% to 21% (figure). Overall, the percentages born at 31–32, 33–34, and &gt;34 wGA were 5.7%, 2.2%, and 1.2%, respectively. An estimated 5.7% of infants with CLD were born at ≥32 wGA, representing 0.9 of every 10,000 US births or ~350 infants annually. Conclusion Fewer than 400 infants are born at ≥32 wGA and diagnosed with CLD annually in the United States. The rationale for excluding this small but high-risk group of infants from the population recommended for RSV immunoprophylaxis is not clear. Funded by AstraZeneca :Disclosures. C. S. Ambrose, AstraZeneca: Employee, Salary and Stocks. X. Jiang, EpiStat Institute: Employee, Consulting fee and Salary. AstraZeneca: Consultant, Consulting fee. K. Mavunda, AstraZeneca: Speaker’s Bureau, Speaker honorarium.

scholarly journals Dynamic Change of Thyroid Hormones With Postmenstrual Age in Very Preterm Infants Born With Gestational Age <32 Weeks: A Multicenter Prospective Cohort Study

2021 ◽  
Vol 11 ◽  
Author(s):  
Ranran Shi ◽  
Ming Zhang ◽  
Yao Chen ◽  
Meiying Han ◽  
Ping Xu ◽  
...  
Keyword(s):  
Cohort Study ◽  
Preterm Infants ◽  
Thyroid Function ◽  
Gestational Age ◽  
Prospective Cohort ◽  
Term Infants ◽  
Very Preterm Infants ◽  
Very Preterm ◽  
Postmenstrual Age ◽  
The Relationship

BackgroundAt present, the relationship between thyrotropin (TSH) and free thyroxine (FT4) in relation to postmenstrual age (PMA) in preterm infants is still unclear, and there is no reliable standard thyroid hormone reference ranges, resulting in different diagnostic criteria for congenital hypothyroidism been used by different newborn screening programs and different countries.ObjectivesTo investigate the relationship between TSH/FT4 and PMA in very preterm infants (VPIs) born with gestational age (GA) &lt;32 weeks and to derive thyroid function reference charts based on PMA.MethodsA prospective cohort study was performed on VPIs born with GA&lt;32 weeks and born in or transferred to the 27 neonatal intensive care units from January 1, 2019 to December 31, 2019. Serial TSH and FT4 values were measured at the end of each week during the first month after birth and also at PMA36 weeks, PMA40 weeks and at discharge, respectively. The 2.5th, 5th, 50th, 95th, and 97.5th percentiles of TSH and FT4 of different PMA groups were calculated to draw the percentile charts based on PMA.Results1,093 preterm infants were included in this study. The percentile charts of TSH and FT4 levels based on PMA were drawn respectively, and the result indicated that the percentile charts of TSH values were gradually increased initially and then decreased with increasing PMA. The 97.5th percentile chart reached the peak at PMA30 weeks (17.38μIU/ml), and then decreased gradually, reaching the same level as full-term infants (9.07μIU/ml) at PMA38–40 weeks. The 2.5th percentile chart of FT4 was at its lowest point at PMA26–27 weeks (5.23pmol/L), then increased slowly with PMA and reached the same level as full-term infants at PMA38–40 weeks (10.87pmol/L). At PMA36 weeks, the reference intervals of the 2.5th to 97.5th percentiles of TSH and FT4 were 1.18–12.3μIU/ml and 8.59–25.98pmol/L, respectively.ConclusionThe percentile charts of TSH and FT4 in VPIs showed characteristic change with PMA. The results prompt that age-related cutoffs, instead of a single reference range, might be more useful to explain the thyroid function of VPIs. And repeated screening is necessary for preterm infants.

Antibody Response to Diphtheria-Tetanus-Pertussis Immunization in Preterm Infants Who Receive Dexamethasone for Chronic Lung Disease

PEDIATRICS ◽  
2004 ◽  
Vol 113 (4) ◽  
pp. 733-737 ◽  
Author(s):  
M. J. Robinson ◽  
C. Heal ◽  
E. Gardener ◽  
P. Powell ◽  
D. G. Sims
Keyword(s):  
Antibody Response ◽  
Lung Disease ◽  
Preterm Infants ◽  
Chronic Lung Disease

Is Chronic Lung Disease in Low Birth Weight Infants Preventable? A Survey of Eight Centers

PEDIATRICS ◽  
1987 ◽  
Vol 79 (1) ◽  
pp. 26-30 ◽  
Author(s):  
Mary Ellen Avery ◽  
William H. Tooley ◽  
Jacob B. Keller ◽  
Suzanne S. Hurd ◽  
M. Heather Bryan ◽  
...  
Keyword(s):  
Birth Weight ◽  
Low Birth Weight ◽  
Lung Disease ◽  
San Francisco ◽  
Chronic Lung Disease ◽  
Multivariate Logistic Regression Analysis ◽  
Low Birth Weight Infants ◽  
Relationship Of ◽  
The Relationship ◽  
Prematurely Born Infants

Chronic lung disease in prematurely born infants, defined as the need for increased inspired oxygen at 28 days of age, was thought to be more common in some institutions than in others. To test this hypothesis, we surveyed the experience in the intensive care nurseries at Columbia and Vanderbilt Universities, the Universities of Texas at Dallas, Washington at Seattle, and California at San Francisco, the Brigham and Women's Hospital in Boston, Texas Children's Hospital in Houston, and Mt Sinai Hospital in Toronto. The survey included 1,625 infants with birth weights of 700 to 1,500 g. We confirmed the relationship of risk to low birth weight, white race, and male sex. Significant differences in the incidence of chronic lung disease were found between institutions even when birth weight, race, and sex were taken into consideration through a multivariate logistic regression analysis. Columbia had one of the best outcomes for low birth weight infants and the lowest incidence of chronic lung disease.

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