scholarly journals Simulating effect of neonate body position on carbon dioxide tension in oxygen tent

2021 ◽  
Vol 18 (5) ◽  
pp. 57-61
Author(s):  
Yu. S. Aleksandrovich ◽  
K. V. Pshenisnov ◽  
R. Vardanjan ◽  
V. Ignatov ◽  
V. Chienas ◽  
...  

Oxygen therapy is a common method of respiratory support, but its use involves the risk of carbon dioxide recycling and the development of hypercapnia in the patient.The aim of the study. Assess the carbon dioxide tension in the oxygen tent depending on the patient's body position in the experimental newborn Model.Materials and Methods. The study was performed on the phantom of the newborn. Influence of 3 patient positions at fresh mixture feed rate 2.5, 5, 7 and 10 l/min is evaluated. Monitoring of the carbon dioxide tension was carried out using Testo 480, measurements were carried out for 60 minutes.Results of the study. A clear relationship was established between the position of the newborn's body and the tension of carbon dioxide in the oxygen tent. The minimum tension of carbon dioxide is noted in the patient's position ≪on the back≪ at a fresh mixture feed rate of 7.5 l/minute and is 527 ± 64 ppm, and the maximum ‒ in the child's position ≪on the stomach≪ at the same oxygen-air mixture feed rate: 1180 ± 63 ppm.Conclusion. The position of the newborn baby's body is the main factor affecting the carbon dioxide stress in the oxygen tent.

PEDIATRICS ◽  
1981 ◽  
Vol 67 (5) ◽  
pp. 626-630
Author(s):  
Thomas A. Hazinski ◽  
Thomas N. Hansen ◽  
Julie A. Simon ◽  
William H. Tooley

Hypoxemia, hypercarbia, and cor pulmonale ultimately occur in most patients with chronic lung disease. Although oxygen therapy may reduce or delay the development of pulmonary hypertension and myocardial failure in these patients, its use is thought to lead to CO2 narcosis and apnea. The effect of O2 administration during sleep has been examined in 12 patients (seven with cystic fibrosis, three with bronchopulmonary dysplasia, one with bronchiolitis obliterans, and one with severe hypersensitivity pneumonitis) using skin surface O2 (Roche) and CO2 (Radiometer) electrodes. Both electrodes were calibrated over wet gas and applied at 44 C. Ten patients had chronic hypercarbia (Paco2 62 ± 19 torr; range 46 to 103 torr) when awake. Humidified oxygen was administered by nasal cannula, Venturi mask, or head hood. Oxygen flow was increased every 20 minutes for 80 minutes or until the patient awoke. In eight of ten patients with hypercarbia and in the two normocarbic patients, skin surface carbon dioxide tension (Psco2) increased by 10% or less as the skin surface oxygen tension (Pso2) was increased. In the remaining two patients with hypercarbia (both had cystic fibrosis) Psco2 increased 18% and 24% as Pso2 was increased. These last two patients with depressed responsiveness to co2 could not be separated from the other patients by clinical or laboratory criteria. It is concluded that skin surface blood gas tensions are a simple and reproducible method for adjusting oxygen therapy in patients with chronic lung disease, and although the response to oxygen varies from patient to patient, most patients with chronic hypercarbia retain their central responsiveness to CO2 during sleep and for them O2 therapy is probably safe.


2020 ◽  
Vol 5 (4) ◽  
pp. 1006-1010
Author(s):  
Jennifer Raminick ◽  
Hema Desai

Purpose Infants hospitalized for an acute respiratory illness often require the use of noninvasive respiratory support during the initial stage to improve their breathing. High flow oxygen therapy (HFOT) is becoming a more popular means of noninvasive respiratory support, often used to treat respiratory syncytial virus/bronchiolitis. These infants present with tachypnea and coughing, resulting in difficulties in coordinating sucking and swallowing. However, they are often allowed to feed orally despite having high respiratory rate, increased work of breathing and on HFOT, placing them at risk for aspiration. Feeding therapists who work with these infants have raised concerns that HFOT creates an additional risk factor for swallowing dysfunction, especially with infants who have compromised airways or other comorbidities. There is emerging literature concluding changes in pharyngeal pressures with HFOT, as well as aspiration in preterm neonates who are on nasal continuous positive airway pressure. However, there is no existing research exploring the effect of HFOT on swallowing in infants with acute respiratory illness. This discussion will present findings from literature on HFOT, oral feeding in the acutely ill infant population, and present clinical practice guidelines for safe feeding during critical care admission for acute respiratory illness. Conclusion Guidelines for safety of oral feeds for infants with acute respiratory illness on HFOT do not exist. However, providers and parents continue to want to provide oral feeds despite clinical signs of respiratory distress and coughing. To address this challenge, we initiated a process change to use clinical bedside evaluation and a “cross-systems approach” to provide recommendations for safer oral feeds while on HFOT as the infant is recovering from illness. Use of standardized feeding evaluation and protocol have improved consistency of practice within our department. However, further research is still necessary to develop clinical practice guidelines for safe oral feeding for infants on HFOT.


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.


1985 ◽  
Vol 5 (3) ◽  
pp. 113
Author(s):  
P. T. Cook ◽  
K. Bernstein ◽  
L. Gisselsson ◽  
L. Jacodsson ◽  
S. Ohrlander ◽  
...  

1960 ◽  
Vol 15 (4) ◽  
pp. 583-588 ◽  
Author(s):  
F. N. Craig ◽  
E. G. Cummings

Two men ran for 20 or 60 seconds while inhaling air, oxygen or 4% carbon dioxide. Inspired respiratory minute volume was determined for each breath. Ventilation increased suddenly in the first breath with minimal changes in end-expiratory carbon dioxide tension and respiratory exchange ratio to a rate that remained constant for 20 seconds before increasing further. The rate of carbon dioxide output was uniform during the first 20 seconds. A 12% grade did not increase ventilation or oxygen uptake during runs of 20 seconds, but in the first minute of recovery, ventilation was 64% greater than after level runs. Inhalation of oxygen inhibited ventilation by 24% in the 20-second periods before and after the end of a 60-second run. Inhalation of carbon dioxide begun at rest produced increments in ventilation and end-expiratory carbon dioxide tension that varied little during running and recovery. In the 20-second runs ventilation varied with speed but appeared independent of ultimate metabolic cost. Submitted on January 21, 1960


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