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Monaldi Archives For Chest Disease =... Nov 2022Oxygen is probably the most commonly prescribed drug in the emergency setting and is a life-saving modality as well. However, like any other drug, oxygen therapy may... (Review)
Review
Oxygen is probably the most commonly prescribed drug in the emergency setting and is a life-saving modality as well. However, like any other drug, oxygen therapy may also lead to various adverse effects. Patients with chronic obstructive pulmonary disease (COPD) may develop hypercapnia during supplemental oxygen therapy, particularly if uncontrolled. The risk of hypercapnia is not restricted to COPD only; it has also been reported in patients with morbid obesity, asthma, cystic fibrosis, chest wall skeletal deformities, bronchiectasis, chest wall deformities, or neuromuscular disorders. However, the risk of hypercapnia should not be a deterrent to oxygen therapy in hypoxemic patients with chronic lung diseases, as hypoxemia may lead to life-threatening cardiovascular complications. Various mechanisms leading to the development of oxygen-induced hypercapnia are the abolition of 'hypoxic drive', loss of hypoxic vasoconstriction and absorption atelectasis leading to an increase in dead-space ventilation and Haldane effect. The international guideline recommends a target oxygen saturation of 88% to 92% in patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) and other chronic lung diseases at risk of hypercapnia. Oxygen should be administered only when oxygen saturation is below 88%. We searched PubMed, EMBASE, and the CINAHL from inception to June 2022. We used the following search terms: "Hypercapnia", "Oxygen therapy in COPD", "Oxygen-associated hypercapnia", "oxygen therapy", and "Hypoxic drive". All types of study are selected. This review will focus on the physiological mechanisms of oxygen-induced hypercapnia and its clinical implications.
Topics: Humans; Oxygen; Hypercapnia; Pulmonary Disease, Chronic Obstructive; Oxygen Inhalation Therapy; Lung Diseases; Hypoxia
PubMed: 36412131
DOI: 10.4081/monaldi.2022.2399 -
Critical Care (London, England) Oct 2012During our medical training, we learned that oxygen administration in patients with chronic obstructive pulmonary disease (COPD) induces hypercapnia through the 'hypoxic... (Review)
Review
During our medical training, we learned that oxygen administration in patients with chronic obstructive pulmonary disease (COPD) induces hypercapnia through the 'hypoxic drive' mechanism and can be dangerous. This mindset frequently results in the reluctance of clinicians to administer oxygen to hypoxemic patients with COPD. However, this fear is not based on evidence in the literature. Here, we will review the impact and pathophysiology of oxygen-induced hypercapnia in patients with acute exacerbation of COPD and recommend a titrated oxygen management.
Topics: Humans; Hypercapnia; Oxygen; Oxygen Inhalation Therapy; Pulmonary Disease, Chronic Obstructive
PubMed: 23106947
DOI: 10.1186/cc11475 -
American Journal of Respiratory and... Dec 2022The long-term effects of using a high-flow nasal cannula for chronic hypercapnic respiratory failure caused by chronic obstructive pulmonary disease remain unclear. To... (Randomized Controlled Trial)
Randomized Controlled Trial
The long-term effects of using a high-flow nasal cannula for chronic hypercapnic respiratory failure caused by chronic obstructive pulmonary disease remain unclear. To assess whether long-term high-flow nasal cannula use reduces the number of exacerbations and improves other physiological parameters in patients with chronic hypercapnic respiratory failure caused by chronic obstructive pulmonary disease. We enrolled 104 participants (aged ⩾40 yr) with daytime hypercapnia (Global Initiative for Chronic Obstructive Lung Disease stages 2-4) receiving long-term oxygen therapy (⩾16 h/d for ⩾1 mo) and randomly assigned them to high-flow nasal cannula/long-term oxygen therapy and long-term oxygen therapy groups. The primary endpoint was the moderate or severe exacerbation rate. We compared changes from baseline in arterial blood gas values, peripheral oxygen saturation, pulmonary function, health-related quality-of-life scores, and the 6-minute-walk test. High-flow nasal cannula use significantly reduced the rate of moderate/severe exacerbations (unadjusted mean count 1.0 vs. 2.5, a ratio of the adjusted mean count between groups [95% confidence interval] of 2.85 [1.48-5.47]) and prolonged the duration without moderate or severe exacerbations. The median time to first moderate or severe exacerbation in the long-term oxygen therapy group was 25 (14.1-47.4) weeks; this was not reached in the high-flow nasal cannula/long-term oxygen therapy group. High-flow nasal cannula use significantly improved health-related quality of life scores, peripheral oxygen saturation, and specific pulmonary function parameters. No safety concerns were identified. A high-flow nasal cannula is a reasonable therapeutic option for patients with stable hypercapnic chronic obstructive pulmonary disease and a history of exacerbations. Clinical trial registered with www.umin/ac.jp (UMIN000028581) and www.clinicaltrials.gov (NCT03282019).
Topics: Humans; Aged; Hypercapnia; Cannula; Noninvasive Ventilation; Quality of Life; Oxygen Inhalation Therapy; Pulmonary Disease, Chronic Obstructive; Respiratory Insufficiency; Oxygen
PubMed: 35771533
DOI: 10.1164/rccm.202201-0199OC -
Respirology (Carlton, Vic.) Apr 2019Non-invasive ventilation (NIV) with bilevel positive airway pressure is a non-invasive technique, which refers to the provision of ventilatory support through the... (Review)
Review
Non-invasive ventilation (NIV) with bilevel positive airway pressure is a non-invasive technique, which refers to the provision of ventilatory support through the patient's upper airway using a mask or similar device. This technique is successful in correcting hypoventilation. It has become widely accepted as the standard treatment for patients with hypercapnic respiratory failure (HRF). Since the 1980s, NIV has been used in intensive care units and, after initial anecdotal reports and larger series, a number of randomized trials have been conducted. Data from these trials have shown that NIV is a valuable treatment for HRF. This review aims to explore the principal areas in which NIV can be useful, focusing particularly on patients with acute HRF (AHRF). We will update the evidence base with the goal of supporting clinical practice. We provide a practical description of the main indications for NIV in AHRF and identify the group of patients with hypercapnic failure who will benefit most from the application of NIV.
Topics: Acute Disease; Humans; Hypercapnia; Noninvasive Ventilation; Pulmonary Disease, Chronic Obstructive; Respiratory Insufficiency
PubMed: 30636373
DOI: 10.1111/resp.13469 -
Respirology (Carlton, Vic.) Apr 2019Patients with end-stage chronic obstructive pulmonary disease (COPD) frequently develop chronic hypercapnic respiratory failure (CHRF), with disabling symptoms and poor... (Review)
Review
Patients with end-stage chronic obstructive pulmonary disease (COPD) frequently develop chronic hypercapnic respiratory failure (CHRF), with disabling symptoms and poor survival. The use of long-term nocturnal non-invasive ventilation (NIV) to treat CHRF in COPD has long been subject of debate due to conflicting evidence. However, since the introduction of high-intensity NIV (HI-NIV) in COPD, physiological and clinical benefits have been shown. HI-NIV refers to specific ventilator settings used for NIV aimed at achieving normocapnia or the lowest partial arterial carbon dioxide pressure (PaCO ) values as possible. This review will provide an overview of existing evidence of the efficacy of HI-NIV stable COPD patients with CHRF. Secondly, we will discuss hypotheses underlying NIV benefit in stable hypercapnic COPD, providing insight into better patient selection and hopefully more individually titrated HI-NIV. Finally, we will provide practical advice on how to initiate and follow-up patients on HI-NIV, with special emphasis on monitoring that should be available during the initiation and follow-up of HI-NIV, and will discuss more extended monitoring techniques that could improve HI-NIV treatment in the future.
Topics: Humans; Hypercapnia; Monitoring, Physiologic; Noninvasive Ventilation; Pulmonary Disease, Chronic Obstructive; Respiratory Insufficiency
PubMed: 30500099
DOI: 10.1111/resp.13450 -
International Journal of Chronic... 2022To evaluate the clinical efficacy of high-flow nasal oxygen therapy (HFNC) and non-invasive ventilation (NIV) in patients with acute exacerbation of chronic obstructive... (Meta-Analysis)
Meta-Analysis Review
High-Flow Nasal Cannula Oxygen Therapy versus Non-Invasive Ventilation for AECOPD Patients After Extubation: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
OBJECTIVE
To evaluate the clinical efficacy of high-flow nasal oxygen therapy (HFNC) and non-invasive ventilation (NIV) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) after extubation.
RESEARCH METHODS
This systematic review and meta-analysis was conducted following the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) statements. The primary outcome measures analyzed included: reintubation rate, mortality, complication rate, and ICU length of stay.
RESULTS
Eight studies were included, with a total of 612 subjects, including 297 in the HFNC group and 315 in the NIV group. The effect of HFNC and NIV on the reintubation rate of AECOPD patients after extubation, RR (1.49 [95% CI,0.95 to 2.33], P = 0.082). Subgroup analysis with or without hypercapnia according to the included AECOPD population, with hypercapnia, RR (0.69 [95% CI,0.33 to 1.44], P=0.317), without hypercapnia, RR (2.61 [95% CI,1.41 to 4.83], P=0.002). Mortality, RR (0.92 [95% CI,0.56 to 1.52], P = 0.752). ICU length of stay, MD (-0.44 [95% CI,-1.01 to 0.13], P = 0.132). Complication rate, RR (0.22 [95% CI,0.13 to 0.39], P = 0.000). After subgroup analysis, the reintubation rate of HFNC and NIV has no statistical difference in patients with hypercapnia, but NIV can significantly reduce the reintubation rate in patients without hypercapnia. In the outcome measures of complication rate, HFNC significantly reduced complication rate compared with NIV. In mortality and ICU length of stay, analysis results showed that HFNC and NIV were not statistically different.
CONCLUSION
According to the available evidence, the application of HFNC can be used as an alternative treatment for NIV after extubation in AECOPD patients with hypercapnia, but in the patients without hypercapnia, HFNC is less effective than NIV.
Topics: Airway Extubation; Cannula; Humans; Hypercapnia; Noninvasive Ventilation; Oxygen; Oxygen Inhalation Therapy; Pulmonary Disease, Chronic Obstructive; Randomized Controlled Trials as Topic; Respiratory Insufficiency
PubMed: 36065316
DOI: 10.2147/COPD.S375107 -
American Journal of Respiratory and... Aug 2020Noninvasive ventilation (NIV) is used for patients with chronic obstructive pulmonary disease (COPD) and chronic hypercapnia. However, evidence for clinical efficacy...
Noninvasive ventilation (NIV) is used for patients with chronic obstructive pulmonary disease (COPD) and chronic hypercapnia. However, evidence for clinical efficacy and optimal management of therapy is limited. Patients with COPD, clinicians who care for them, and policy makers. We summarized evidence addressing five PICO (patients, intervention, comparator, and outcome) questions. The GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach was used to evaluate the certainty in evidence and generate actionable recommendations. Recommendations were formulated by a panel of pulmonary and sleep physicians, respiratory therapists, and methodologists using the Evidence-to-Decision framework.) We suggest the use of nocturnal NIV in addition to usual care for patients with chronic stable hypercapnic COPD (conditional recommendation, moderate certainty); ) we suggest that patients with chronic stable hypercapnic COPD undergo screening for obstructive sleep apnea before initiation of long-term NIV (conditional recommendation, very low certainty); ) we suggest not initiating long-term NIV during an admission for acute-on-chronic hypercapnic respiratory failure, favoring instead reassessment for NIV at 2-4 weeks after resolution (conditional recommendation, low certainty); ) we suggest not using an in-laboratory overnight polysomnogram to titrate NIV in patients with chronic stable hypercapnic COPD who are initiating NIV (conditional recommendation, very low certainty); and ) we suggest NIV with targeted normalization of Pa in patients with hypercapnic COPD on long-term NIV (conditional recommendation, low certainty) This expert panel provides evidence-based recommendations addressing the use of NIV in patients with COPD and chronic stable hypercapnic respiratory failure.
Topics: Chronic Disease; Humans; Hypercapnia; Noninvasive Ventilation; Pulmonary Disease, Chronic Obstructive; Time Factors
PubMed: 32795139
DOI: 10.1164/rccm.202006-2382ST -
International Journal of Chronic... 2023This study aimed to evaluate the clinical outcomes of high-flow nasal cannula (HFNC) compared with conventional oxygen therapy (COT) in patients with hypercapnic chronic... (Meta-Analysis)
Meta-Analysis Review
Comparison of High-Flow Nasal Cannula with Conventional Oxygen Therapy in Patients with Hypercapnic Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis.
PURPOSE
This study aimed to evaluate the clinical outcomes of high-flow nasal cannula (HFNC) compared with conventional oxygen therapy (COT) in patients with hypercapnic chronic obstructive pulmonary disease (COPD), including arterial partial pressure of carbon dioxide (PaCO), arterial partial pressure of oxygen (PaO), respiratory rate (RR), treatment failure, exacerbation rates, adverse events and comfort evaluation.
PATIENTS AND METHODS
PubMed, EMBASE and the Cochrane Library were retrieved from inception to September 30, 2022. Eligible trials were randomized controlled trials and crossover studies comparing HFNC and COT in hypercapnic COPD patients. Continuous variables were reported as mean and standard derivation and calculated by weighted mean differences (MD), while dichotomous variables were shown as frequency and proportion and calculated by odds ratio (OR), with the 95% confidence intervals (Cl). Statistical analysis was performed using RevMan 5.4 software.
RESULTS
Eight studies were included, five with acute hypercapnia and three with chronic hypercapnia. In acute hypercapnic COPD, short-term HFNC reduced PaCO (MD -1.55, 95% CI: -2.85 to -0.25, I² = 0%, p <0.05) and treatment failure (OR 0.54, 95% CI: 0.33 to 0.88, I² = 0%, p<0.05), but there were no significant differences in PaO (MD -0.36, 95% CI: -2.23 to 1.52, I² = 45%, p=0.71) and RR (MD -1.07, 95% CI: -2.44 to 0.29, I² = 72%, p=0.12). In chronic hypercapnic COPD, HFNC may reduce COPD exacerbation rates, but there was no advantage in improving PaCO (MD -1.21, 95% CI: -3.81 to 1.39, I² = 0%, p=0.36) and PaO (MD 2.81, 95% CI: -1.39 to 7.02, I² = 0%, p=0.19).
CONCLUSION
Compared with COT, short-term HFNC reduced PaCO and the need for escalating respiratory support in acute hypercapnic COPD, whereas long-term HFNC reduced COPD exacerbations rates in chronic hypercapnia. HFNC has great potential for treating hypercapnic COPD.
Topics: Humans; Pulmonary Disease, Chronic Obstructive; Oxygen; Hypercapnia; Cannula; Respiratory Insufficiency; Noninvasive Ventilation; Oxygen Inhalation Therapy; Randomized Controlled Trials as Topic
PubMed: 37215746
DOI: 10.2147/COPD.S402506 -
The Journal of Physiology Apr 2017Gases are sensed by lung cells and can activate specific intracellular signalling pathways, and thus have physiological and pathophysiological effects. Carbon dioxide... (Review)
Review
Gases are sensed by lung cells and can activate specific intracellular signalling pathways, and thus have physiological and pathophysiological effects. Carbon dioxide (CO ), a primary product of oxidative metabolism, can be sensed by eukaryotic cells eliciting specific responses via recently identified signalling pathways. However, the physiological and pathophysiological effects of high CO (hypercapnia) on the lungs and specific lung cells, which are the primary site of CO elimination, are incompletely understood. In this review, we provide a physiological and mechanistic perspective on the effects of hypercapnia on the lungs and discuss the recent understanding of CO modulation of the alveolar epithelial function (lung oedema clearance), epithelial cell repair, innate immunity and airway function.
Topics: Animals; Carbon Dioxide; Humans; Hypercapnia; Immunity, Innate; Lung; Pulmonary Alveoli
PubMed: 28044311
DOI: 10.1113/JP273781 -
Journal of Cerebral Blood Flow and... Dec 2019Brain function, the brain's metabolic activity, cerebral blood flow (CBF), and intracranial pressure are intimately linked within the tightly autoregulated regime of...
Brain function, the brain's metabolic activity, cerebral blood flow (CBF), and intracranial pressure are intimately linked within the tightly autoregulated regime of intracranial physiology in which the role of tissue viscoelasticity remains elusive. We applied multifrequency magnetic resonance elastography (MRE) paired with CBF measurements in 14 healthy subjects exposed to 5-min carbon dioxide-enriched breathing air to induce cerebral vasodilatation by hypercapnia. Stiffness and viscosity as quantified by the magnitude and phase angle of the complex shear modulus, |*| and , as well as CBF of the whole brain and 25 gray matter sub-regions were analyzed prior to, during, and after hypercapnia. In all subjects, whole-brain stiffness and viscosity increased due to hypercapnia by 3.3 ± 1.9% and 2.0 ± 1.1% which was accompanied by a CBF increase of 36 ± 15%. Post-hypercapnia, |*| and reduced to normal values while CBF decreased by 13 ± 15% below baseline. Hypercapnia-induced viscosity changes correlated with CBF changes, whereas stiffness changes did not. The MRE-measured viscosity changes correlated with blood viscosity changes predicted by the Fåhræus-Lindqvist model and microvessel diameter changes from the literature. Our results suggest that brain viscoelastic properties are influenced by microvessel blood flow and blood viscosity: vasodilatation and increased blood viscosity due to hypercapnia result in an increase in MRE values related to viscosity.
Topics: Adult; Cerebrovascular Circulation; Elasticity; Elasticity Imaging Techniques; Gray Matter; Humans; Hypercapnia; Male; Models, Cardiovascular; Viscosity
PubMed: 30182788
DOI: 10.1177/0271678X18799241