scholarly journals High Concentration Oxygen and Hypercapnia in Respiratory Disease

2021 ◽  
Author(s):  
◽  
Janine Pilcher

<p>Oxygen-induced elevations in arterial carbon dioxide tension have been demonstrated in patients with chronic obstructive pulmonary disease (COPD), asthma, pneumonia, obesity hypoventilation syndrome (OHS) and acute lung injury. A randomised controlled trial (RCT) in acute exacerbations of COPD (AECOPD) found an over two-fold increase in mortality in patients randomised to high concentration oxygen, compared to titrated oxygen. These findings support guideline recommendations for titration of oxygen therapy to a target oxygen saturation range, reducing the risks of hypoxaemia and hyperoxaemia.   This thesis focuses on the potential implications of oxygen-induced elevations in carbon dioxide in the acute clinical setting. The reviews and studies in the following chapters are all aimed at addressing gaps in knowledge which may have practical implications for oxygen therapy and/or the identification of patients at risk of oxygen-induced hypercapnia in clinical practice.   Numerous studies have demonstrated that high concentration oxygen continues to be administered to acutely unwell patients, despite guideline recommendations for titrated therapy. The first study in this thesis is a clinical audit evaluating the effects of a staff education program, which included face-to-face and written training for ambulance staff. The education program was associated with reduced the rates of high concentration oxygen administration to patients with AECOPD. This suggests active education may increase adherence to oxygen guidelines among clinical staff.   The ability to avoid hypoxaemia and hyperoxaemia during titrated oxygen therapy relies on appropriate lower and upper target oxygen saturation limits, which may be impacted on by pulse oximeter accuracy. The second study in this thesis is a multicentre observational study in which 400 paired pulse oximeter (SpO₂) and arterial blood gas saturation (SaO₂) values were collected in the hospital setting. A SpO₂ <92% had 100% sensitivity for detecting SaO₂<90%. This indicates guideline recommended target oxygen saturations of 92-96% adequately avoid hypoxaemia.  Two studies in OHS patients have investigated the effects of oxygen administration on carbon dioxide, however their designs, including recruitment of stable participants, have limited their generalisability to clinical practice. Therefore, a cross over RCT was conducted in 24 morbidly obese hospital inpatients, randomised to the order they received high concentration and titrated oxygen, each for 60 minutes. The mean change in the transcutaneous partial pressure of carbon dioxide (PtCO₂) from baseline was 3.2 mmHg higher during high concentration oxygen, compared with titrated oxygen (P=0.002). This supports guideline recommendations to titrate oxygen in patients with obesity, regardless of whether they have a diagnosis of OHS or not.  The effects of oxygen in patients with bronchiectasis, neuromuscular disease or kyphoscoliosis are uncertain. Stable patients with these conditions were recruited to double-blind randomised cross over trials administering air and 50% oxygen, each for 30 minutes. A trial was also performed in stable COPD patients for comparison. There was no significant change in PtCO₂ with oxygen therapy in the neuromuscular disease/kyphoscoliosis patients. In the bronchiectasis and COPD patients, oxygen was associated with increased PtCO₂ from baseline compared to air, but the differences were not clinically significant (0.4 mmHg, P=0.012 and 1.3 mmHg, P<0.001, respectively). The lack of a clinically significant PtCO₂ increase in the COPD patients indicated the study findings were unlikely to be generalisable to the clinical setting, and highlights the potential limitations in applying data from stable participants to patients who require acute oxygen therapy.  These studies support current guideline recommendations for titrated oxygen therapy, provide insight into the limits of studying the effects of oxygen in stable participants, and demonstrate the utility of an educational program to aid the translation of research findings into relevant changes in clinical practice.</p>

2021 ◽  
Author(s):  
◽  
Janine Pilcher

<p>Oxygen-induced elevations in arterial carbon dioxide tension have been demonstrated in patients with chronic obstructive pulmonary disease (COPD), asthma, pneumonia, obesity hypoventilation syndrome (OHS) and acute lung injury. A randomised controlled trial (RCT) in acute exacerbations of COPD (AECOPD) found an over two-fold increase in mortality in patients randomised to high concentration oxygen, compared to titrated oxygen. These findings support guideline recommendations for titration of oxygen therapy to a target oxygen saturation range, reducing the risks of hypoxaemia and hyperoxaemia.   This thesis focuses on the potential implications of oxygen-induced elevations in carbon dioxide in the acute clinical setting. The reviews and studies in the following chapters are all aimed at addressing gaps in knowledge which may have practical implications for oxygen therapy and/or the identification of patients at risk of oxygen-induced hypercapnia in clinical practice.   Numerous studies have demonstrated that high concentration oxygen continues to be administered to acutely unwell patients, despite guideline recommendations for titrated therapy. The first study in this thesis is a clinical audit evaluating the effects of a staff education program, which included face-to-face and written training for ambulance staff. The education program was associated with reduced the rates of high concentration oxygen administration to patients with AECOPD. This suggests active education may increase adherence to oxygen guidelines among clinical staff.   The ability to avoid hypoxaemia and hyperoxaemia during titrated oxygen therapy relies on appropriate lower and upper target oxygen saturation limits, which may be impacted on by pulse oximeter accuracy. The second study in this thesis is a multicentre observational study in which 400 paired pulse oximeter (SpO₂) and arterial blood gas saturation (SaO₂) values were collected in the hospital setting. A SpO₂ <92% had 100% sensitivity for detecting SaO₂<90%. This indicates guideline recommended target oxygen saturations of 92-96% adequately avoid hypoxaemia.  Two studies in OHS patients have investigated the effects of oxygen administration on carbon dioxide, however their designs, including recruitment of stable participants, have limited their generalisability to clinical practice. Therefore, a cross over RCT was conducted in 24 morbidly obese hospital inpatients, randomised to the order they received high concentration and titrated oxygen, each for 60 minutes. The mean change in the transcutaneous partial pressure of carbon dioxide (PtCO₂) from baseline was 3.2 mmHg higher during high concentration oxygen, compared with titrated oxygen (P=0.002). This supports guideline recommendations to titrate oxygen in patients with obesity, regardless of whether they have a diagnosis of OHS or not.  The effects of oxygen in patients with bronchiectasis, neuromuscular disease or kyphoscoliosis are uncertain. Stable patients with these conditions were recruited to double-blind randomised cross over trials administering air and 50% oxygen, each for 30 minutes. A trial was also performed in stable COPD patients for comparison. There was no significant change in PtCO₂ with oxygen therapy in the neuromuscular disease/kyphoscoliosis patients. In the bronchiectasis and COPD patients, oxygen was associated with increased PtCO₂ from baseline compared to air, but the differences were not clinically significant (0.4 mmHg, P=0.012 and 1.3 mmHg, P<0.001, respectively). The lack of a clinically significant PtCO₂ increase in the COPD patients indicated the study findings were unlikely to be generalisable to the clinical setting, and highlights the potential limitations in applying data from stable participants to patients who require acute oxygen therapy.  These studies support current guideline recommendations for titrated oxygen therapy, provide insight into the limits of studying the effects of oxygen in stable participants, and demonstrate the utility of an educational program to aid the translation of research findings into relevant changes in clinical practice.</p>


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.


2021 ◽  
Author(s):  
Ramón Casillas‐Hernández ◽  
Karla Janeth Arévalo‐Sainz ◽  
Jose Reyes Gonzalez‐Galaviz ◽  
María del Carmen Rodríguez‐Jaramillo ◽  
Rafael Apolinar Bórquez‐López ◽  
...  

2010 ◽  
Vol 4 (8) ◽  
pp. 1217-1227 ◽  
Author(s):  
S. N. Gaydamaka ◽  
V. V. Timofeev ◽  
Yu. V. Guryev ◽  
D. A. Lemenovskiy ◽  
G. P. Brusova ◽  
...  

2016 ◽  
Vol 73 (1) ◽  
Author(s):  
A. Corrado ◽  
T. Renda ◽  
S. Bertini

Long term oxygen therapy (LTOT) has been shown to improve the survival rate in Chronic Obstructive Pulmonary Disease (COPD) patients with severe resting hypoxemia by NOTT and MRC studies, published more than 25 years ago. The improved survival was found in patients who received oxygen for more than 15 hours/day. The effectiveness of LTOT has been documented only in stable COPD patients with severe chronic hypoxemia at rest (PaO255%. In fact no evidence supports the use of LTOT in COPD patients with moderate hypoxemia (55&lt;PaO2&lt;65 mmHg), and in those with decreased oxygen saturation (SO2&lt;90%) during exercise or sleep. Furthermore, it is generally accepted without evidence that LTOT in clinical practice is warranted in other forms of chronic respiratory failure not due to COPD when arterial blood gas criteria match those established for COPD patients. The prescription of oxygen in these circumstances, as for unstable patients, increases the number of patients receiving supplemental oxygen and the related costs. Comorbidities are likely to affect both prognosis and health outcomes in COPD patients, but at the moment we do not know if LTOT in these patients with complex chronic diseases and mild-moderate hypoxemia could be of any use. For these reasons a critical revision of the actual guide lines indications for LTOT in order to optimise effectiveness and costs, and future research in the areas that have not previously been addressed by NOTT and MRC studies, are mandatory.


2018 ◽  
Vol 104 (3) ◽  
pp. F324-F325 ◽  
Author(s):  
Elinor Charles ◽  
Katie Hunt ◽  
Vadivelam Murthy ◽  
Christopher Harris ◽  
Anne Greenough

BackgroundPrevious surveys have demonstrated that neonatal resuscitation practices on the delivery suite vary between UK units, particularly according to the hospital’s neonatal unit’s level. Our aim was to determine if recent changes to the Resuscitation Council guidelines had influenced clinical practice.MethodsSurveys of resuscitation practices at UK delivery units carried out in 2012 and 2017 were compared.ResultsComparing 2017 with 2012, initial resuscitation using air was more commonly used in both term (98% vs 75%, p<0.001) and preterm (84% vs 34%, p<0.001) born infants. Exhaled carbon dioxide monitoring was more frequently employed in 2017 (84% vs 19%, p<0.001). There were no statistically significant differences in practices according to the level of neonatal care provided by the hospital.ConclusionThere have been significant changes in neonatal resuscitation practices in the delivery suite since 2012 regardless of the different levels of neonatal care offered.


2008 ◽  
Vol 65 (7) ◽  
pp. 521-524
Author(s):  
Zorica Lazic ◽  
Ivan Cekerevac ◽  
Ljiljana Novkovic ◽  
Vojislav Cupurdija

Background/Aim. Oxygen therapy is a necessary therapeutic method in treatment of severe chronic respiratory failure (CRF), especially in phases of acute worsening. Risks which are to be taken into consideration during this therapy are: unpredictable increase of carbon dioxide in blood, carbonarcosis, respiratory acidosis and coma. The aim of this study was to show the influence of oxygen therapy on changes of arterial blood carbon dioxide partial pressure. Methods. The study included 93 patients in 104 admittances to the hospital due to acute exacerbation of CFR. The majority of the patients (89.4%) had chronic obstructive pulmonary disease (COPD), while other causes of respiratory failure were less common. The effect of oxygenation was controlled through measurement of PaO2 and PaCO2 in arterial blood samples. To analyze the influence of oxygen therapy on levels of carbon dioxide, greatest values of change of PaO2 and PaCO2 values from these measurements, including corresponding PaO2 values from the same blood analysis were taken. Results. The obtained results show that oxygen therapy led to the increase of PaO2 but also to the increase of PaCO2. The average increase of PaO2 for the whole group of patients was 2.42 kPa, and the average increase of PaCO2 was 1.69 kPa. There was no correlation between the initial values of PaO2 and PaCO2 and changes of PaCO2 during the oxygen therapy. Also, no correlation between the produced increase in PaO2 and change in PaCO2 during this therapy was found. Conclusion. Controlled oxygen therapy in patients with severe respiratory failure greatly reduces the risk of unwanted increase of PaCO2, but does not exclude it completely. The initial values of PaO2 and PaCO2 are not reliable parameters which could predict the response to oxygen therapy.


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