In this multicenter study the comparison of the mass flow distribution and redistribution versus the relative blood flow per lobe (as a surrogate for Ventilation/ Perfusion (V/Q) matching) with functional respiratory imaging (FRI) and arterial blood gas (ABG) values will be evaluated in hypercapnic Chronic Obstructive Pulmonary Disease (COPD) patients. Therefore a low dose Computed Tomography (CT) scan will be taken in a population of 30 patients with non-invasive ventilation (NIV) and in a control group of 10 patients without NIV. The CT-scan will be used for FRI ...
Background: Sleep hypoventilation has been proposed as a cause of progressive hypercapnic respiratory failure and death in patients with severe chronic obstructive pulmonary disease (COPD).. Objective: To determine the effects of nocturnal, non-invasive bi-level pressure support ventilation (NIV) on survival, lung function and quality of life in severe hypercapnic COPD.. Design: A multicentre, open-label, randomized controlled trial of NIV plus long term oxygen therapy (LTOT) versus LTOT alone.. Setting: University Hospital sleep/ respiratory medicine departments.. Patients: Severe, stable, smoking-related COPD (FEV1.0 , 1.5 L or ,50% predicted and FEV1.0/FVC ,60% with awake PaCO2 , 46mmHg and on LTOT for at least 3 months) and age less than 80 years. Patients with sleep apnea (Apnea-hypopnea Index , 20/ hr) or morbid obesity (BMI ,40) were excluded.. Intervention: Night-time bilevel pressure support ventilation.. Measurements: Survival, spirometry, arterial blood gases, polysomnography, general ...
All information about the latest scientific publications of the Clínica Universidad de Navarra. Hyperleptinaemia, respiratory drive and hypercapnic response in obese patients
The effects of chronic respiratory failure (hypoxia and hypercapnia) on the contractile properties of cardiac muscle are not established. A study was performed of the isometric contractile properties of isolated papillary muscle removed from rats exposed in a normobaric environmental chamber to 28 days of hypoxia (fractional inspired oxygen (FIO2) 10%, fractional inspired carbon dioxide (FICO2) less than 1%), hypercapnia (FIO2 21%, FICO2 5%), and hypoxia with hypercapnia (FIO2 10%, FICO2 5%). Rats exposed to both hypoxia and hypoxia with hypercapnia developed selective right ventricular hypertrophy. Exposure to hypercapnia alone did not alter right ventricular weight. No change in right ventricular papillary muscle contractility per unit muscle mass was observed as measured by maximum active tension, maximum rate of rise or fall of tension, or time to peak tension. Rat cardiac muscle adapts successfully to the altered acid-base environment and increased work load associated with prolonged ...
This study was undertaken to investigate the contribution of carbon dioxide to respiratory control made by the carotid bodies and vagus nerves. Small eupneically breathing dogs, anesthetized with IV ketamine HCL were subjected to inspired CO2 concentrations of 3% while recording simultaneously tidal volume, inspiratory and expiratory airflow rates, and single neuron activity in or near the ventral respiratory group. The burst activity of the ventral respiratory group neuron was considered to be representative of the final integrated motor output of the brain stem respiratory complex. This data provided information concerning: (1) the relationship between group and airflow, (2) the latency response to CO2, (3) the contribution of the carotid body to the hypercapnic response, (4) the vagal contribution to the hypercapnic response. Several specified measures of neuron activity were altered as airflow patterns changed. Subsequent analyses showed correlation between airflow parameters and neuron ...
Putnam, R. W., Ritucci, N. A., & Dean, J. B. (1997). Effect of Hypercapnia on Intracellular pH in Neurons from Chemosensitive and Insensitive Areas of Medullary Brainstem Slices. The FASEB Journal, 11 (3), 3676 ...
We investigated the effect of different levels of hypercapnia on total pulmonary resistance (RL) in 13 subjects ranging from nonsnorers with low RL to snorers with high RL and dynamic narrowing of the upper airway during inspiration. Added CO2 was ad
Authors: Kostoglou K, Debert CT, Poulin MJ, Mitsis GD.. We examined the time-varying characteristics of cerebral autoregulation and hemodynamics during a step hypercapnic stimulus by using recursively estimated multivariate (two-input) models which quantify the dynamic effects of mean arterial blood pressure (ABP) and end-tidal CO2 tension ( [Formula: see text] ) on middle cerebral artery blood flow velocity (CBFV). Beat-to-beat values of ABP and CBFV, as well as breath-to-breath values of [Formula: see text] during baseline and sustained euoxic hypercapnia were obtained in 8 female subjects. The multiple-input, single-output models used were based on the Laguerre expansion technique, and their parameters were updated using recursive least squares with multiple forgetting factors. The results reveal the presence of nonstationarities that confirm previously reported effects of hypercapnia on autoregulation, i.e. a decrease in the MABP phase lead, and suggest that the incorporation of [Formula: ...
Case 1: A seven-year-old lurcher presented after an episode of severe respiratory distress and collapse, which had been treated by the referring veterinary surgeon with a tracheostomy tube placement. Laryngeal paralysis was diagnosed, and the dog was scheduled to undergo left-sided laryngoplasty. During anaesthesia, the dog developed marked hypercapnia and respiratory acidosis during spontaneous ventilation. Initiation of manual ventilation and endotracheal suctioning did not improve the ventilation. On extubation, a blood clot was discovered, occluding approximately two-third of the endotracheal tube (ETT) lumen. Case 2: A two-month-old Jack Russell terrier was presented for ligation of a patent ductus arteriosus. Intraoperatively, the dog developed sudden severe hypercapnia and hypoxaemia. Manual ventilation was initiated, and two attempts of recruiting the lung were made, which initially improved the ventilation. Postoperatively, before extubation, a second episode of severe hypercapnia and ...
The ability of brain cells to regulate intracellular pH (pHi) and several phosphate metabolites was evaluated during 1 h of hypercapnia (inspiratory CO2 fraction of 0.10 and 0.05) in anesthetized rats by 31P high-field (145.6 MHz) nuclear magnetic re
Extended hypercapnia exposure led to the restoration of NBC1 mRNA within 2 wk and to a threefold higher expression at the end of the trial, indicating a differentiated response to acute vs. long-term hypercapnic conditions. As with Na+-K+-ATPase and NHE1, the change in message likely results in changing protein levels. In case of the Na+/HCO3− cotransporter, elevated protein contents would support maintenance of elevated bicarbonate levels (Fig. 6B), as described for several fishes (9, 27, 33, 50). The threefold increment of NBC1 mRNA at the end of the trial emphasizes an important role of this transporter in steady-state acid-base regulation under long-term hypercapnia.. Since HCO3− accumulation under hypercapnia is usually accompanied by a decrease of Cl− concentration, a role for gill Cl−/HCO3− exchange has been postulated (see introduction). However, AE1 mRNA expression in Z. viviparus was only slightly affected, with a trend to decrease initially under hypercapnia, reaching a 50% ...
Although the ventilatory and heart rate responses to hypoxia are known to vary widely among subjects, it is not known how exercise or hypercapnia influence the intersubject variability of these responses. If the intersubject variability increases under such conditions, the inherent response of individuals will have more impact on ventilation and heart rate under a variety of hypoxic conditions during exercise or with hypercapnia than at rest or with normocapnia. Seventeen healthy male volunteers underwent tests to measure ventilatory response to isocapnic progressive hypoxia three times respectively: at rest; during CO2 inhalation (end-tidal carbon dioxide tension (PET,CO2) raised by 5 torr from the baseline level); and during mild exercise with a cycle ergometer (12.5 W) in a supine position. The mean (SEM) value of hypoxic ventilatory response (HVR) (delta minute ventilation (VE)/delta arterial oxygen saturation (Sa,O2) was significantly increased both in the exercise and hypercapnic runs ...
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A 60-year-old woman presented to our hospital with severe hypercapnic respiratory failure in the absence of a prior smoking history. She reported a 1-day history of increased dyspnoea and a cough productive of green sputum. Her medical history was significant for severe idiopathic scoliosis, cleft p.... ...
The successful treatment of hypercapnic respiratory failure with oral modafinil Helen Parnell,1 Ginny Quirke,1 Sally Farmer,1 Sumbo Adeyemo,2 Veronica Varney11Respiratory Department, 2Pharmacy Department, St Helier Hospital, Carshalton, Surrey, UKAbstract: Hypercapnic respiratory failure is common in advanced chronic obstructive pulmonary disease and is usually treated by nasal ventilation. Not all patients requiring such ventilation can tolerate it, with anxiety and phobia influencing their reaction, along with treatment failure. We report the case histories of six patients with hypercapnic respiratory failure who were at risk of death due to refusal of nasal ventilation or its failure despite ongoing treatment. We report their improvement with oral modafinil 200 mg tablets used as a respiratory stimulant, which led to discharge, improved arterial blood gases, and offset further admissions with hypercapnic respiratory failure. This drug is licensed for narcolepsy and is said to stimulate the
Davidson, AC, Banham, S, Elliott, M, Kennedy, D, Gelder, C, Glossop, A, Church, AC, Creagh-Brown, B, Dodd, JW, Felton, T et al, Foex, B, Mansfield, L, McDonnell, L, Parker, R, Patterson, CM, Sovani, M and Thomas, L. (2016) BTS/ICS guideline for the ventilatory management of acute hypercapnic respiratory failure in adults ...
Objective: We describe a patient with a prolonged and severe hypercapnia occurring during an episode of status asthmaticus induced by ophthalmic instillation of carteolol. Setting: Prehospital Emergen
Respirology. 2010 Feb;15(2):283-8. doi: 10.1111/j.1440-1843.2009.01665.x. Epub 2009 Nov 23. Multicenter Study; Randomized Controlled Trial; Research Support, Non-U.S. Govt
In the mammalian brain, nitric oxide (NO) is responsible for a vasodilatory tonus as well as the elevation of cerebral blood flow (CBF) induced by hypercapnia. There have been few comparative studies of cerebral vasoregulation in lower vertebrates. Using epi-illumination microscopy in vivo to observe CBF velocity on the brain surface (cerebral cortex), we show that turtles (Trachemys scripta) exposed to hypercapnia (inspired PCO2 = 4.9 kPa) displayed a 62% increase in CBF velocity, while systemic blood pressure remains constant. Exposing turtles to a PCO2 of 14.9 kPa caused an additional increase in CBF velocity, to 104% above control values, as well as a 30% increase in systemic blood pressure. The elevated CBF velocity during hypercapnia could not be blocked by a systemic injection of the NO synthase (NOS) inhibitor NG-nitro-L-arginine (L-NA). However, L-NA injection caused a temporary stop in CBF as well as a persistent increase in systemic blood pressure, suggesting that there is a NO tonus ...
Hypercapnia has been shown in animal experiments to induce pulmonary hypertension. This study measured the sensitivity and time course of the human pulmonary vascular response to sustained (4 h) hypercapnia and hypocapnia. Twelve volunteers undertook three protocols: 1) 4-h euoxic (end-tidal Po(2) = 100 Torr) hypercapnia (end-tidal Pco(2) was 10 Torr above normal), followed by 2 h of recovery with euoxic eucapnia; 2) 4-h euoxic hypocapnia (end-tidal Pco(2) was 10 Torr below normal) followed by 2 h of recovery; and 3) 6-h air breathing (control). Pulmonary vascular resistance was assessed at 0.5- to 1-h intervals by using Doppler echocardiography via the maximum tricuspid pressure gradient during systole. Results show progressive changes in pressure gradient over 1-2 h after the onset or offset of the stimuli, and sensitivities of 0.6 to 1 Torr change in pressure gradient per Torr change in end-tidal Pco(2). The human pulmonary circulatory response to changes in Pco(2) has a slower time course and
BACKGROUND. Noninvasive ventilation (NIV) has a success rate of about 75% during an episode of severe hypercapnic respiratory failure in COPD patients. Recently, a new minimally invasive CO2 extracorporeal removal device (ECCO2-R, Decap; Hemodec, Salerno, Italy) consisting of a pump-driven veno-venous hemofiltration system has been developed. The main features of this system are a low extracorporeal blood flow (,500 ml/min), using a small (14-French) double-lumen catheter, and a relatively small infusion rate of heparin.. METHODS. 15 COPD patients with severe hypercapnic respiratory failure failing NIV after a trial of 2-4 hrs and meeting the criteria for intubation (i.e.pH , 7.30 and hypercapnia (no changes or increased in the PaCO2 baseline values), respiratory rate , 35 b/min, moderate to severe dyspnea) were enrolled.. The average duration of treatment with Decap was 18-24 hours. Intubation was required in 2/15 (13%) patients, and other 2 had procedure related complications (i.e bleeding and ...
In this study, we prospectively identified adult patients after cardiac arrest and determined the prevalence of hypocapnia exposure and hypercapnia exposure during the first 24 hours after ROSC. Our objective was to test whether post-ROSC exposure to hypocapnia and hypercapnia was associated with poor neurological function at hospital discharge. We found that 36% of patients had any hypocapnia exposure, and 42% had any hypercapnia exposure. By the use of multivariable logistic regression, including multiple sensitivity analyses, we found that both hypocapnia exposure and hypercapnia exposure after ROSC were independent predictors of poor neurological function at hospital discharge. These findings suggest that both hypocapnia and hypercapnia are common during the initial post-ROSC period and are independently associated with poor neurological outcome.. The 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care recommend that ventilation ...
Rationale: Opioids are commonly used to relieve dyspnea, but clinical data are mixed and practice varies widely. Objectives: Evaluate the effect of morphine on dyspnea and ventilatory drive under well-controlled laboratory conditions. Methods: Six healthy volunteers received morphine (0.07 mg/kg) and placebo intravenously on separate days (randomized, blinded). We measured two responses to a CO2 stimulus: (1) perceptual response (breathing discomfort; described by subjects as "air hunger") induced by increasing partial pressure of end-tidal carbon dioxide (PetCO2) during restricted ventilation, measured with a visual analog scale (range, "neutral" to "intolerable"); and (2) ventilatory response, measured in separate trials during unrestricted breathing. Measurements and Main Results: We determined the PetCO2 that produced a 60% breathing discomfort rating in each subject before morphine (median, 8.5 mm Hg above resting PetCO2). At the same PetCO2 after morphine administration, median breathing ...
Looking for online definition of permissive hypercapnic ventilation in the Medical Dictionary? permissive hypercapnic ventilation explanation free. What is permissive hypercapnic ventilation? Meaning of permissive hypercapnic ventilation medical term. What does permissive hypercapnic ventilation mean?
Gerard J. Criner, MD, FACP, FACCP, Chair and Professor of Thoracic Medicine and Surgery at the Lewis Katz School of Medicine at Temple University and Director of the Temple Lung Center, offered comments to Reuters Health for an article about initiating chronic non-invasive ventilation at home for patients with chronic obstructive pulmonary disease (COPD) and stable hypercapnic respiratory failure. The study, which was conducted by researchers in the Netherlands, was published online in the journal Thorax. Dr. Criner was not involved in the research. MD Alert picked up the Reuters Health report. ...
Carbon dioxide (CO2) is a by-product of aerobic breathing; it is carried and dissolved in blood and bound to haemoglobin and plasma proteins. The arterial carbon dioxide level (pCO2) represents the balance between CO2 production and elimination.1 Avery et al 2 hypothesised that tolerance of pCO2 above the physiological range may … ...
4.4. Ventilatory Responses to Hypoxic Challenges in Morphine-Treated Rats- Episode H1. H1 elicited markedly smaller increases in fr in MOR rats although resting fr was not diminished. As such, morphine elicited latent effects on systems including those within the carotid bodies that drive the hypoxic responses. Our data are consistent with evidence that the negative effects of opioids in humans may be latent since the morphine metabolite, M6G, does not affect resting ventilatory parameters whereas it substantially blunts the ventilatory response to hypercapnic challenge [5]. Since morphine did not markedly blunt the increase in Vt during H1, it is evident that it did not negatively affect neural drive to the chest muscles or diaphragm. This is supported by the finding that Ti in MOR rats (elevated immediately prior to exposure to hypoxia) decreased substantially during H1. Taken together, our data support the concept that morphine affected brainstem centers responsible for generating breathing ...
Background: The mechanisms underlying cerebral hypercapnic vasodilatation are not fully understood. Objective: To investigate the role of nitric oxide (NO) and ATPsensitive potassium (KATP) channels in basal blood flow regulation and hypercapnia-induced vasodilatation in rabbit cerebral blood ves-
a, b, Representative examples of plethysmographic recordings (breathing frequency) during exposure to hypoxia (10% O2) and hypercapnia (5% CO2) in a wild-type FRA mouse and in a Olfr78−/− FRA mouse. c, Plethysmographic recordings (breathing frequency as a measure of time) of the ventilatory response to hypercapnia (5% CO2) performed on wild-type (n = 10) and Olfr78−/− (n = 10) FRA mice. Each data point represents the mean ± s.e.m. of the values for the group of 10 mice. CO2 (percentage CO2) tensions are indicated at the bottom. d, Breathing frequency during exposure to hypercapnia (5% CO2) in Olfr78−/− FRA mice (n = 10) compared to their wild-type littermates (n = 10). e, Breathing frequency during exposure to hypoxia (10% O2) in Olfr78−/− LEX mice compared to wild-type LEX mice (n = 10 for each genotype, 7 pairs in a C57BL/6 background, 3 pairs in a C57BL/6:129S5 mixed background, 9 out of 10 pairs are sex-matched littermates). f, Breathing frequency during exposure to hypoxia ...
Hypercapnia, elevated partial pressure of CO2 in blood and tissue, develops in many patients with chronic severe obstructive pulmonary disease and other advanced lung disorders. Patients with advanced disease frequently develop bacterial lung infections, and hypercapnia is a risk factor for mortality in such individuals. We previously demonstrated that hypercapnia suppresses induction of NF-κB-regulated innate immune response genes required for host defense in human, mouse, and Drosophila cells, and it increases mortality from bacterial infections in both mice and Drosophila. However, the molecular mediators of hypercapnic immune suppression are undefined. In this study, we report a genome-wide RNA interference screen in Drosophila S2* cells stimulated with bacterial peptidoglycan. The screen identified 16 genes with human orthologs whose knockdown reduced hypercapnic suppression of the gene encoding the antimicrobial peptide Diptericin (Dipt), but did not increase Dipt mRNA levels in air. In ...
1. The effect on respiration of a single dose of propranolol has been studied in normal subjects.. 2. The degree of β-adrenoreceptor blockade was assessed in terms of the impaired heart-rate response to progressive exercise and the plasma propranolol concentration.. 3. No effect of propranolol was demonstrated on either the ventilatory response to rebreathing CO2 in hyperoxia, or the response to progressive isocapnic hypoxia. Simple indices of maximal expiratory flow (FEV1.0% and PEFR) were also unchanged.. 4. The absence of any effect of propranolol on the chemical control of breathing in man is discussed in relation to the conflicting literature.. ...
The human pulmonary vasculature constricts in response to hypercapnia and hypoxia, with important consequences for homeostasis and adaptation. One function of these responses is to direct blood flow away from poorly-ventilated regions of the lung. In humans it is not known whether the stimuli of hypercapnia and hypoxia constrict the pulmonary blood vessels independently of each other or whether they act synergistically, such that the combination of hypercapnia and hypoxia is more effective than the sum of the responses to each stimulus on its own. We independently controlled the alveolar partial pressures of carbon dioxide (Paco 2) and oxygen (Pao 2) to examine their possible interaction on human pulmonary vasoconstriction. Nine volunteers each experienced sixteen possible combinations of four levels of Paco 2 (+6, +1, -4 and -9 mmHg, relative to baseline) with four levels of Pao 2 (175, 100, 75 and 50 mmHg). During each of these sixteen protocols Doppler echocardiography was used to evaluate cardiac
From the abstract: "Hypercapnia, elevated partial pressure of CO2 in blood and tissue, develops in many patients with chronic severe obstructive pulmonary disease and other advanced lung disorders. Patients with advanced disease frequently develop bacterial lung infections ... We previously demonstrated that hypercapnia suppresses induction of NF-κB-regulated innate immune response genes ... However, the molecular mediators of hypercapnic immune suppression are undefined. In this study, we report a genome-wide RNA interference screen in Drosophila S2* cells stimulated with bacterial peptidoglycan. The screen identified 16 genes with human orthologs whose knockdown reduced hypercapnic suppression of the gene encoding the antimicrobial peptide Diptericin (Dipt), but did not increase Dipt mRNA levels in air. In vivo tests of one of the strongest screen hits, zinc finger homeodomain 2 (Zfh2; mammalian orthologs ZFHX3/ATBF1 and ZFHX4), demonstrate that reducing zfh2 function using a mutation or RNA ...
We investigated whether the involuntary breathing movements (IBM) during the struggle phase of breath holding, together with peripheral vasoconstriction and progressive hypercapnia, have a positive effect in maintaining cerebral blood volume. The central hemodynamics, arterial oxygen saturation, brain regional oxyhemoglobin (bHbO(2)), deoxyhemoglobin, and total hemoglobin changes and IBM were monitored during maximal dry breath holds in eight elite divers. The frequency of IBM increased (by approximately 100%), and their duration decreased ( approximately 30%), toward the end of the struggle phase, whereas the amplitude was unchanged (compared with the beginning of the struggle phase). In all subjects, a consistent increase in brain regional deoxyhemoglobin and total hemoglobin was also found during struggle phase, whereas bHbO(2) changed biphasically: it initially increased until the middle of the struggle phase, with the subsequent relative decline at the end of the breath hold. Mean arterial ...
TY - JOUR. T1 - On the optimization of imaging protocol for the mapping of cerebrovascular reactivity. AU - Ravi, Harshan. AU - Thomas, Binu P.. AU - Peng, Shin Lei. AU - Liu, Hanli. AU - Lu, Hanzhang. PY - 2016/3/1. Y1 - 2016/3/1. N2 - Background To devise an improved blood-oxygen-level-dependent (BOLD) imaging protocol for cerebrovascular reactivity (CVR) measurement that can remove a known artifact of negative values. Methods Theoretical and simulation studies were first performed to understand the biophysical mechanism of the negative CVR signals, through which improved BOLD sequence parameters were proposed. This was achieved by equating signal intensities between cerebrospinal fluid and blood, by means of shortening the echo time (TE) of the BOLD sequence. Then, 10 healthy volunteers were recruited to participate in an experimental study, in which we compared the CVR results of two versions of the optimized ("Opt1" and "Opt2") protocols with that of the standard protocol at 3 Tesla. Two ...
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Nocturnal alterations in gas exchange, such as oxygen desaturation and hypercapnia, are an important clinical problem in patients with chronic obstructive pulmonary disease (COPD). Potential forms of treatment include supplemental oxygen, pharmacolog
OSA leads to increased cardiovascular disease (CVD). The mechanisms underlying vascular dysfunction in OSA include sympathetic activation and oxidative stress (from intermittent hypoxia, hypercapnia, and arousals). These perturbations result in reduced production of endothelium-dependent vasodilators such as nitric oxide (44). Moreover, OSA is associated with a proinflammatory and hypercoagulable state-another pathway that causes vascular injury (45). These mechanisms explain the observation that OSA severity, as indicated by AHI, is significantly associated with risk of stroke (odds ratio 2.5) in patients with type 2 diabetes (46). It should be noted that this study included older and obese populations with a high prevalence of OSA (86%). The independent effects of OSA on CVD should be further examined in lean and younger populations with type 2 diabetes.. There are limited empirical data regarding acceleration of other organ system dysfunction in patients with type 2 diabetes as a result of ...
REPIRATORY FAILURE DEFINITION Failure of the respiratory system to meetthe metabolic demands of the body resulting in hypoxia with or without hypercapnia
TY - JOUR. T1 - Thyrotoxic periodic paralysis complicated by acute hypercapnic respiratory failure and ventricular tachycardia. AU - Wu, Chung Ze. AU - Wu, Yao Kuang. AU - Lin, Jiunn Diann. AU - Kuo, Shi Wen. PY - 2008/12/1. Y1 - 2008/12/1. N2 - Background: Thyrotoxic hypokalemic periodic paralysis in combination with an acute episode of general flaccid paralysis and hypokalemia is common in young Asian men with hyperthyroidism. We report the very rare complications of involvement of the respiratory muscles and ventricular tachycardia in this disorder. Summary: A 29-year-old man exhibited profound paralysis after prolonged fasting. Severe hypokalemia was noted (K +: 1.4 mmol/L). Although the patient was treated with potassium chloride, he suffered from respiratory distress and chest tightness. Arterial blood gas indicated acute hypercapnic respiratory failure (pCO 2: 118.9 mmHg), and ventricular tachycardia was documented by electrocardiogram. The patient was intubated for ventilatory support ...
Land-based aquaculture facilities experience occasional hypercapnic conditions due to the accumulation of the metabolic waste product carbon dioxide. Pre-gonadal Lytechinus variegatus (horizontal diameter=20 mm) were exposed to control (608 µatm pCO2, pH 8.1) or hypercapnic conditions (1738 µatm pCO2, pH 7.7) in synthetic seawater for 14 weeks. Sea urchins exposed to hypercapnic conditions exhibited significantly slower growth (reduced dry matter production), primarily due to reduced test production. Higher fecal production rates and lower ash absorption efficiency (%) in individuals exposed to hypercapnic conditions suggest the ability to process or retain dietary carbonates may have been affected. Significant increases in neutral lipid storage in the gut and increased soluble protein storage in the gonads of individuals exposed to hypercapnic conditions suggest alterations in nutrient metabolism and storage. Furthermore, organic production and energy allocation increased in the lantern of ...
TY - JOUR. T1 - Intravascular membrane oxygenation and carbon dioxide removal with IVOX. T2 - Can improved design and permissive hypercapnia achieve adequate respiratory support during severe respiratory failure?. AU - Zwischenberger, J. B.. AU - Cardenas, V. J.. AU - Tao, W.. AU - Niranjan, S. C.. AU - Clark, J. W.. AU - Bidani, A.. PY - 1994. Y1 - 1994. N2 - The intravenacaval oxygenator and carbon dioxide removal device (IVOX) conceived by Mortensen at CardioPulmonics is a diffusion-limited device capable of removing 30% of CO2 production of an adult at normocapnia with minimal reduction in ventilator requirements. Through mathematical modeling, an ex vivo venovenous bypass circuit to model the vena cava and animal models of severe smoke inhalation injury, the practice of permissive hypercapnia has been established to enhance CO2 removal by IVOX. By allowing the blood Pco2 to rise gradually, the CO2 excretion by IVOX can be linearly increased in a 1:1 relationship. Experimental and clinical ...
Delayed but successful response to noninvasive ventilation in COPD patients with acute hypercapnic respiratory failure Malcolm Lemyze,1,2 Quentin Bury,3 Aurélie Guiot,4 Marie Jonard,1,2 Usman Mohammad,2 Nicolas Van Grunderbeeck,5 Gaelle Gasan,1 Didier Thevenin,2 Jihad Mallat2 1Department of Respiratory and Critical Care Medicine, Schaffner Hospital, Lens, 2Intensive Care Unit, Arras Hospital, Arras, 3Respiratory Intermediate Care Unit, Béthune Beuvry Hospital, Béthune, 4Department of Cardiology, Bois Bernard Hospital, Bois Bernard, 5Respiratory Step Down Unit, Schaffner Hospital, Lens, France Background: We evaluated a new noninvasive ventilation (NIV) protocol that allows the pursuit of NIV in the case of persistent severe respiratory acidosis despite a first NIV challenge in COPD patients with acute hypercapnic respiratory failure (AHRF). Patients and methods: A prospective observational multicentric pilot study was conducted in three tertiary hospitals over a 12-month study
To investigate which neurons in the medulla oblongata produced the nuclear protein FOS during stimulation of respiration by hypercapnia, we subjected six anaesthetized cats to 10% CO2 in air for one hour. Four animals inhaled room air. Coronal sections from the medulla oblongata were processed for FOS immunohistochemistry. Only the retrotrapezoid nucleus (RTN) of the animals exposed to CO2 contained a large population of labelled neurons. This indicates that RTN neurons are strongly activated during hypercapnia.
TY - JOUR. T1 - Effects of hypercapnia and hypocapnia on [Ca2+]i mobilization in human pulmonary artery endothelial cells. AU - Nishio, Kazumi. AU - Suzuki, Yukio. AU - Takeshita, Kei. AU - Aoki, Takuya. AU - Kudo, Hiroyasu. AU - Sato, Nagato. AU - Naoki, Katsuhiko. AU - Miyao, Naoki. AU - Ishii, Makoto. AU - Yamaguchi, Kazuhiro. PY - 2001/6. Y1 - 2001/6. N2 - The hydrogen ion is an important factor in the alteration of vascular tone in pulmonary circulation. Endothelial cells modulate vascular tone by producing vasoactive substances such as prostacyclin (PGI2) through a process depending on intracellular Ca2+ concentration ([Ca2+]i). We studied the influence of CO2-related pH changes on [Ca2+]i and PGI2 production in human pulmonary artery endothelial cells (HPAECs). Hypercapnic acidosis appreciably increased [Ca2+]i from 112 ± 24 to 157 ± 38 nmol/l. Intracellular acidification at a normal extracellular pH increased [Ca2+]i comparable to that observed during hypercapnic acidosis. The ...
In a study of 6 men aged 29 to 48 we studied the effect of water body immersion during air or pure oxygen, or oxygen - 4 % CO2 gas mixture breathing upon pulmonary volumes and respiratory biomechanics (using bodyplethysmography), the extent of lung hydration (two-frequency impedansometry), and pulmonary metabolic function (by determination of the concentration of biologically active substances in the condensate of the exhaled air). We found an additive nature of immersion/hyperoxic effects upon the respiratory and metabolic pulmonary functions manifested in an acceleration and growth of a deficit in pulmonary vital capacity, a bronchoconstriction effect, increase of a lung hydration, and decrease of serotonin catabolism. Contrary to our expectation, we did non find any potentiation of oxygen induced toxic effects upon the lungs during immersion/hyperoxia/hypercapnia exposures ...
The effect of lung-protective permissive hypercapnia in intracerebral pressure in patients with subarachnoid haemorrhage and ARDS. A retrospective study. Petridis, Athanasios K.; Doukas, Alexandros; Kienke, Sven; Maslehaty, Homajoun; Mahvash, Mehran; Barth, Harald; Mehdorn, Hubertus Maximilian // Acta Neurochirurgica;Dec2010, Vol. 152 Issue 12, p2143 Objective: Lung protective ventilation has a beneficial effect in treating patients with acute respiratory distress syndrome (ARDS). An effect of this ventilation modality is hypercapnia, which leads to increased cerebral blood flow. Since increased cerebral blood flow can induce brain oedema... ...
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Title:Ventilation Therapy for Patients Suffering from Obstructive Lung Diseases. VOLUME: 8 ISSUE: 1. Author(s):Sven A. Jungblut, Lena M. Heidelmann, Andreas Westerfeld, Hagen Frickmann, Mareike K. Korber and Andreas E. Zautner. Affiliation:UMG-Labor, Institut für Klinische Chemie/Zentrallabor, Universitätsmedizin Göttingen, Robert- Koch-Straße 40, D-37075 Göttingen, Germany.. Keywords:ARDS, asthma, COPD, emphysema, obstruction, PEEP, permissive hypercapnia, ventilation therapy.. Abstract:Severe bronchial obstruction due to one of the major pulmonary diseases: asthma, COPD, or emphysema often requires mechanical ventilation support. Otherwise, patients are at risk of severe hypooxygenation with consecutive overloading and dilatation of the right cardiac ventricle with subsequent failure. This review focuses on how to manage a calculated ventilation therapy of patients suffering from bronchial obstruction and relevant patents. Options and pitfalls of invasive and non-invasive ventilation in ...
development under hypoxia. Physiol Genomics 29: 260-266, 2007). Ryu J; Vicencio AG, Yeager M, Kashgarian M, Haddad GG, Eickelberg O. Differential expression of Matrix Metalloproteinases and their inhibitors in human and mouse lung development. Thrombosis and Haemostasis, (2005) 94(1):175-83.. Li GY, Zhou D, Vicencio A, Ryu J, Xue J, Kannan, A, Gavrialov O and Haddad GG. Effect of carbon dioxide on neonatal mouse lung: a genomic approach. Journal of Applied Physiology, (2005) 101:1556-1564. Alejandre-Alcazar MA, Michiels-Corsten M, Vicencio AG, Reiss I, Ryu J, de Krijger RR, Haddad GG, Tibboel D, Seeger W, Eickelberg O, Morty RE. TGF-beta signaling is dynamically regulated during the alveolarization of rodent and human lungs. Developmental Dynamics, (2008) 237 (1): 259-69. Douglas R; Ryu J; Kanaan A; Rivero M; Dugan L; Haddad GG; Ali S. Neuronal death during combined intermittent hypoxia/hypercapnia is due to mitochondrial dysfunction. American Journal of Physiology - Cell Physiology, (2010) 298: ...