PULMONARY FUNCTION IN THE NEWBORN INFANT

PEDIATRICS ◽  
1962 ◽  
Vol 30 (6) ◽  
pp. 975-989
Author(s):  
N. M. Nelson ◽  
L. S. Prod'hom ◽  
R. B. Cherry ◽  
P. J. Lipsitz ◽  
C. A. Smith
Keyword(s):  
Pulmonary Function ◽  
Respiratory Distress ◽  
Newborn Infant ◽  
Dead Space ◽  
Clinical Course ◽  
Average Difference ◽  
Alveolar Dead Space ◽  
Physiological Dead Space ◽  
New Born ◽  
Pulmonary Capillary

The arterial-alveolar tension gradient for CO2 has been investigated in 17 normal new born infants and in 15 with some degree of respiratory distress. Whereas the normal infants had virtually no Pco2 gradient from pulmonary capillary to alveolus, an average difference of 13.9 mm Hg was detected in sick infants. This gradient for Pco2 is caused by increased alveolar (and total physiological dead space, the relative amount of which closely parallels the clinical course of the disease. The data obtained indicate the increase in alveolar dead space to be largely due to poor perfusion of ventilated alveoli. In severely ill infants more than 60% of ventilated alveoli appear to be under-perfused.

scholarly journals End-tidal to arterial PCO2 ratio: a bedside meter of the overall gas exchanger performance

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Matteo Bonifazi ◽  
Federica Romitti ◽  
Mattia Busana ◽  
Maria Michela Palumbo ◽  
Irene Steinberg ◽  
...  
Keyword(s):  
Ct Scan ◽  
Dead Space ◽  
Progressive Increase ◽  
Venous Admixture ◽  
Perfect Gas ◽  
Alveolar Dead Space ◽  
Physiological Dead Space ◽  
End Tidal ◽  
The Right ◽  
The Ideal

Abstract Background The physiological dead space is a strong indicator of severity and outcome of acute respiratory distress syndrome (ARDS). The “ideal” alveolar PCO2, in equilibrium with pulmonary capillary PCO2, is a central concept in the physiological dead space measurement. As it cannot be measured, it is surrogated by arterial PCO2 which, unfortunately, may be far higher than ideal alveolar PCO2, when the right-to-left venous admixture is present. The “ideal” alveolar PCO2 equals the end-tidal PCO2 (PETCO2) only in absence of alveolar dead space. Therefore, in the perfect gas exchanger (alveolar dead space = 0, venous admixture = 0), the PETCO2/PaCO2 is 1, as PETCO2, PACO2 and PaCO2 are equal. Our aim is to investigate if and at which extent the PETCO2/PaCO2, a comprehensive meter of the “gas exchanger” performance, is related to the anatomo physiological characteristics in ARDS. Results We retrospectively studied 200 patients with ARDS. The source was a database in which we collected since 2003 all the patients enrolled in different CT scan studies. The PETCO2/PaCO2, measured at 5 cmH2O airway pressure, significantly decreased from mild to mild–moderate moderate–severe and severe ARDS. The overall populations was divided into four groups (~ 50 patients each) according to the quartiles of the PETCO2/PaCO2 (lowest ratio, the worst = group 1, highest ratio, the best = group 4). The progressive increase PETCO2/PaCO2 from quartile 1 to 4 (i.e., the progressive approach to the “perfect” gas exchanger value of 1.0) was associated with a significant decrease of non-aerated tissue, inohomogeneity index and increase of well-aerated tissue. The respiratory system elastance significantly improved from quartile 1 to 4, as well as the PaO2/FiO2 and PaCO2. The improvement of PETCO2/PaCO2 was also associated with a significant decrease of physiological dead space and venous admixture. When PEEP was increased from 5 to 15 cmH2O, the greatest improvement of non-aerated tissue, PaO2 and venous admixture were observed in quartile 1 of PETCO2/PaCO2 and the worst deterioration of dead space in quartile 4. Conclusion The ratio PETCO2/PaCO2 is highly correlated with CT scan, physiological and clinical variables. It appears as an excellent measure of the overall “gas exchanger” status.

scholarly journals Potential Effects of Corticosteroids on Physiological Dead-Space Fraction in Acute Respiratory Distress Syndrome

2012 ◽  
Vol 57 (3) ◽  
pp. 377-383 ◽  
Author(s):  
J. M. Raurich ◽  
M. Ferreruela ◽  
J. A. Llompart-Pou ◽  
M. Vilar ◽  
A. Colomar ◽  
...  
Keyword(s):  
Acute Respiratory Distress Syndrome ◽  
Respiratory Distress Syndrome ◽  
Respiratory Distress ◽  
Dead Space ◽  
Distress Syndrome ◽  
Physiological Dead Space

scholarly journals Penggunaan Ventilatory Ratio dan Alveolar Dead Space Fraction sebagai Prediktor Mortalitas pada Pasien COVID-19 dengan Acute Respiratory Distress Syndrome

2021 ◽  
Vol 9 (1) ◽  
pp. 10-17
Author(s):  
Muh Kemal Putra ◽  
Arie Utarian ◽  
Bambang Pujo Semedi ◽  
Christrijogo Soemartono Waloejo ◽  
Hardiono
Keyword(s):  
Acute Respiratory Distress Syndrome ◽  
Respiratory Distress Syndrome ◽  
Respiratory Distress ◽  
Dead Space ◽  
Distress Syndrome ◽  
Alveolar Dead Space

Pada pasien COVID-19 dengan ARDS terjadi gangguan oksigenasi dan ventilasi. Menurut kriteria Berlin ARDS, oksigenasi diukur dengan PaO2/FiO2, namun tidak mengukur ventilasi alveolar yang diukur dengan dead space yang dapat terjadi akibat kondisi, seperti kerusakan endotel, mikrotrombus, dan penggunaan ventilator yang berlebih. Tujuan penelitian ini menganalisis penggunaan ventilatory ratio (VR) dan dead space fraction (Vd/Vt) sebagai prediktor mortalitas pasien COVID-19 ARDS. Penelitian ini adalah analitik kohort retrospektif. Data dikumpulkan dari rekam medik pasien COVID-19 yang dirawat di RIK RSUD Dr. Soetomo periode Juni–September 2020 dengan teknik total sampling terhadap subjek yang memenuhi kriteria inklusi dan tidak termasuk eksklusi. Data yang dikumpulkan adalah nilai VR dan Vd/Vt (diambil dari data laboratorium), kondisi klinis pasien dan pengaturan ventilator 24 jam pertama setelah terintubasi. Penelitian ini didapatkan 77 dari 80 subjek yang memenuhi kriteria. Nilai VR berhubungan dengan mortalitas secara signifikan dengan nilai p 0,001; cut off 1,84; sensitivitas 84,2%; spesifisitas 85%; RR 30,22; CI 95%: 7,31–124,89. Vd/Vt dan mortalitas menunjukkan hubungan yang signifikan terhadap mortalitas dengan nilai p 0.001. Uji analisis Spearman VR dengan Vd/Vt didapatkan hasil korelasi yang kuat dengan koefisien korelasi 0,704 dan p 0,001. Simpulan, nilai VR dan Vd/Vt dapat digunakan sebagai prediktor mortalitas pasien COVID-19 dengan ARDS dan keduanya mempunyai korelasi yang kuat. VR dapat menggantikan Vd/Vt.

Gas Exchange during Exercise in Healthy People: I. the Physiological Dead-Space Volume

1976 ◽  
Vol 51 (4) ◽  
pp. 323-333 ◽  
Author(s):  
Christine A. Bradley ◽  
E. A. Harris ◽  
Eve R. Seelye ◽  
R. M. L. Whitlock
Keyword(s):  
Carbon Dioxide ◽  
Dead Space ◽  
Confidence Limit ◽  
Carbon Dioxide Tension ◽  
Physiological Dead Space ◽  
Carbon Dioxide Output ◽  
Pulmonary Capillary ◽  
Dead Space Volume ◽  
Capillary Temperature ◽  
Space Volume

1. Physiological dead-space volume (VD) was measured in twenty-four healthy men and women aged from 20 to 71 years, at rest and at two rates of work on a treadmill, whilst breathing air and breathing oxygen. 2. The effect of correction of arterial carbon dioxide tension (Pa,co2) to pulmonary capillary temperature on the resulting value for VD was investigated. We find that the effect is substantial and that a correction should be made. 3. Equations have been derived for the prediction of normal VD during exercise. The best prediction was given by a regression on height, age, carbon dioxide output, ventilation and respiratory frequency, with an upper 95% confidence limit of +81 ml.

scholarly journals MEASUREMENT OF LUNG DEAD SPACE VOLUME BY CAPNOVOLUMETRY

2020 ◽  
pp. 471-477
Author(s):  
T.A. MIROSHKINA ◽  
◽  
S.A. SHUSTOVA ◽  
Keyword(s):  
Dead Space ◽  
Alveolar Dead Space ◽  
Volumetric Capnography ◽  
Equal Area ◽  
Physiological Dead Space ◽  
Dead Space Volume ◽  
Anatomical Dead Space ◽  
The Difference ◽  
Space Volume

The article provides information on the lung dead space – a part of the respiratory volume that does not participate in gas exchange. The anatomical and alveolar dead spaces jointly together form the physiological dead space. The article describes methods for determining the volume of dead spaces using the capnovolumetry. The volume of physiological dead space is calculated using the C. Bohr equation. The volume of anatomical dead space can be determined using the equal area method proposed by W.S. Fowler. The volume of the alveolar dead space is the difference of volumes of the physiological and anatomical dead spaces. In pathology, the volume of the alveolar space and, consequently, physiological dead space can increase significantly. Determination of the volume of dead space is the significant criterion for diagnostic and predicting the outcome of a number of diseases. Keywords: Physiological dead space , anatomical dead space , alveolar dead space , capnovolumetry, volumetric capnography.

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