Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020440 (hypercapnia)
 7,939 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To define the parameters of respiratory insufficiency in OSA, 114 consecutive patients (108 men, six women) were prospectively studied. In addition to standard polysomnography, they underwent pulmonary function tests, right heart catheterization, and ventilatory response tests to hypercapnia. Nineteen patients (19 percent) had a resting PAP greater than or equal to 20 mm Hg. Multiple regression analysis showed that FEV1 and PaO2 (both with a negative coefficient) and PaCO2 (with a positive coefficient) significantly contributed to PAP. Thirteen patients (12 percent) had a PaCO2 greater than or equal to 45 mm Hg. A multiple regression analysis showed that FEV1 and the minute ventilation at PETCO2 = 60 mm Hg (both with a negative coefficient) and the cumulative apnea duration (with a positive coefficient) significantly contributed to PaCO2. Thirty-seven patients (33 percent) had a PaO2 less than or equal to 65 mm Hg. A multiple regression analysis showed that FEV1 (with a positive coefficient) and the hypopnea + apnea index (with a negative coefficient) significantly contributed to PaO2. These data confirm that impaired daytime pulmonary function (diffuse airway obstruction) contributes to the development of daytime pulmonary hypertension, hypoxemia, and hypercapnia in OSA patients. They show that the amount of sleep-related breathing disorders also plays a significant role.
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PMID:Pulmonary hypertension, hypoxemia, and hypercapnia in obstructive sleep apnea patients. 279 65

The purpose of this observational study was to determine whether hypercarbia or oxygen desaturation occurred during our current regimens of deep sedation or general anaesthesia of infants and children undergoing cardiac catheterization. Data were gathered prospectively from 50 consecutive infants and children aged 4 months to 12 years undergoing cardiac catheterization. Several anaesthetists used the following regimens, which were not randomized: 1) propofol. 1.5-2.0 mg.kg-1 and fentanyl 1 microgram.kg-1 IV over 2 min for induction, followed by propofol infusion of 100-150 micrograms.kg-1.min-1; 2) fentanyl 2-3 micrograms.kg-1 and midazolam 0.1-0.2 mg.kg-1 IV over 10-15 min; 3) ketamine 8 mg.kg-1 IM, or 4) same as regimens 1 or 2, plus pancuronium, intubation and controlled ventilation. Regimens 1, 2, and 3 were associated with spontaneous ventilation through the natural airway. End-tidal carbon dioxide tension (PetCO2), SpO2, and respiratory rate were monitored for 60 min. The three regimens employing spontaneous ventilation through the natural airway were associated with both statistically and clinically significant increases in PetCO2 and decreases in SpO2. This raises the possibility that acute exacerbation of PAP and PVR may occur in pulmonary hypertensive patients. In contrast, PetCO2 and SpO2 did not change significantly from baseline in the controlled ventilation group.
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PMID:Changes in carbon dioxide tension and oxygen saturation during deep sedation for paediatric cardiac catheterization. 883 83

Exposure to hypercapnia and electrical stimulation of the carotid sinus nerve (CSN) has been shown to induce c-fos expression in several brain stem regions including the nucleus tractus solitarius (NTS). To test whether the labeled neurons were activated directly by hypercapnia or secondarily via the carotid bodies (sinus nerve), adult rats were exposed to either air or 14-16% CO2 for 1 h. Experiments were done on eight groups: (1) exposure to air, (2) exposure to CO2, (3) chronic CSN denervation/CO2, (4) chronic unilateral CSN denervation/CO2, (5) chronic sham CSN denervation/CO2, (6) anesthetized/CO2, (7) anesthetized and acute vagotomy/CO2, and (8) premedicated with morphine, 10 mg s.c., 20 min before exposure to CO2. After exposure to CO2 or air the rats were anesthetized, perfused with 4% paraformaldehyde and the brains processed for immunohistochemical staining for c-fos protein using the PAP (i.e. peroxidase anti-peroxidase) technique. Labeled neurons in the area of the NTS in every second 50- "mu"m section were counted and their position plotted using a microscope and camera lucida attachment. Rats exposed to CO2 had a significantly greater number of labeled neurons in the NTS than those exposed to air. Other interventions, such as CSN denervation, surgery, anesthesia, vagotomy or injection of morphine did not significantly affect the level of c-fos expression in rats exposed to hypercapnia, indicative of central stimulation rather than secondary peripheral input. These responsive neurons may be part of a widespread central chemoreceptive complex.
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PMID:Effect of sinus denervation and vagotomy on c-fos expression in the nucleus tractus solitarius after exposure to CO2. 892 4

Continuous positive airway pressure (CPAP) and different types of non-invasive ventilation (NIV) have been studied in obesity hypoventilation syndrome such as bi-level PAP with back-up rate (BPAP-BUR), BPAP without BUR, and the new hybrid devices that target a pre-set volume by adjustment of pressure support (VT-PS). Although several studies have compared one PAP intervention with the other, none has compared all four in a head-to-head design, which formed the basis of this network meta-analysis. PubMed and Web of Science were searched for potentially includable randomised active comparator trials. Changes in partial pressure of carbon dioxide (PaCO2 ) and Epworth Sleepiness Score (ESS) were the primary outcomes of interest. Network meta-analysis was done in R program using the 'frequentist' framework. A total of seven trials were included. Only VT-PS and BPAP-BUR showed statistically significant reductions in PaCO2 compared to control, with no significant inter-PAP differences except for the comparison between VT-PS and CPAP. Only VT-PS showed a statistically significant improvement in ESS as compared to control, with no other significant inter-PAP differences. P-score ranking (based on effect size and standard errors) and Hasse diagram ranked VT-PS and BPAP as superior to other PAPs for both primary outcomes. There were no significant differences between the different PAP interventions for hospital or emergency department admissions. The results of this network meta-analysis suggest superiority of VT-PS and BPAP over other PAP interventions at least for daytime hypercapnia and subjective daytime somnolence.
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PMID:A network meta-analysis of different positive airway pressure interventions in obesity hypoventilation syndrome. 3278 56