View clinical trials related to Hypercapnia.
Filter by:The proposed study will measure the time from the end of surgery until the time patients meet the discharge criteria from the postoperative anesthesia care unit and the time from the end of surgery until the patients regained cognitive function after anesthesia.
A comparative study which compares the end-tidal carbon dioxide and oxygen saturation levels of patients during endoscopy which have used either the new oral-nasal oxygenating device (TwinGuard), or a standard bite block plus nasal cannulae using an equivalent flow rate of oxygen.
The purpose of this study is to assess the efficacy of noninvasive ventilation in the prevention of extubation failure and mortality in patients with chronic respiratory disorders and hypercapnic respiratory failure during spontaneous breathing.
The investigators hypothesize that continuation of non-invasive ventilation (NIV) at home after an episode of acute hypercapnic respiratory failure (AHRF) treated by NIV in COPD patients would reduce the likelihood of death and recurrent AHRF requiring NIV or intubation. The investigators designed this study in a way that recruited COPD patients would be started on home NIV or sham treatment after an episode of AHRF requiring acute NIV. The patients are acclimatised to NIV application after a few days of acute use. The investigators chose occurrence of life-threatening event (recurrent AHRF and death) as the primary endpoint.
The investigators will test the hypotheses that mild hypercapnia and supplemental oxygen reduce wound infection risk in patients undergoing colon resection. The investigators will simultaneously test the hypothesis that low-dose dexamethasone (a common treatment for postoperative nausea and vomiting) does not increase infection risk.
Wearing N95 masks may have adverse physical effect on medical staff
This study will use magnetic resonance imaging (MRI) to examine and compare changes in blood flow and blood volume in the brains of normal volunteers and patients with multiple sclerosis (MS). Patients with MS-an inflammatory disease that attacks the brain and spine-may have new blood vessel formation (called angiogenesis) within the brain that may or may not contribute to the disease or help in repairing the brain. It is not known if these new vessels behave in the same way as the naturally occurring vessels. MRI uses a strong magnetic field and radio waves to generate brain images that provide information on brain chemistry, function, and blood flow. The results of this study may lead to a better understanding of MS. Healthy normal volunteers and patients with multiple sclerosis 18 years of age and older may be eligible for this study. Normal volunteers must have no history of signs or symptoms of central nervous system disease. Patients with MS will be recruited from the NIH Neuroimmunology MS clinic. All participants will undergo MRI. For this procedure, the subject lies still on a table that slides into a narrow metal cylinder (the MRI scanner). Scanning varies from 20 minutes to 3 hours, with most scans lasting between 45 and 90 minutes. During the scan, the subject wears earplugs to muffle loud knocking noises caused by electrical switching of the radio frequency circuits. The subject can communicate with the MRI staff at all times during the procedure. During the scan, the subject wears a mask and breathes in room air or air containing 6% carbon dioxide (CO2). (Room air contains approximately 0.04% CO2, which is about 150 times less than the 6% CO2. Air that is normally breathed out contains about 5% CO2.) Breathing 6% CO2 increases the amount of blood flow in the brain that can be measured using MRI. The total duration of a single 6 percent CO2 inhalation will not exceed 10 minutes. A catheter (thin plastic tube) is placed in a vein in the subject's arm before he or she enters the scanner. At some point during the scan, a contrast agent called gadolinium DTPA is injected into the vein through the catheter. This agent enables clearer images of the brain.
This study will use magnetic resonance imaging (MRI) to examine the role of prostaglandins-a type of fatty acid with hormone-like actions-in the regulation of brain blood flow. The results will provide information on how to better use this technique to study brain function, which, in turn, may lead to a better understanding of certain illnesses and more effective treatments. Healthy normal volunteers 18 years of age and older may be eligible for this study. Participants will fill out a health questionnaire and undergo a history, physical examination and MRI studies. MRI is a diagnostic tool that uses a strong magnetic field and radio waves instead of X-rays to show structural and chemical changes in tissues. During the scanning, the subject lies on a table in a narrow cylinder containing a magnetic field. An intercom system allows the subject to speak with the staff member performing the study at all times during the procedure. Four separate studies will be done-two carbon dioxide inhalation studies and two functional activation studies-as follows: Carbon dioxide inhalation (indomethacin): This study is done in two parts. In both parts, an MRI brain scan is done. During the scan, the subject inhales an air mixture containing 6% carbon dioxide through a facemask or mouthpiece. Blood pressure and heart rate are monitored during inhalation of the mixture. For the second part of the study, indomethacin-a non-steroidal anti-inflammatory drug-is injected through a catheter (thin flexible tube) in an arm vein. Indomethacin inhibits prostaglandin production. Total scan time averages between 45 and 90 minutes, with a maximum of 2 hours. Carbon dioxide inhalation (rofecoxib and celecoxib): This study is identical to the one above, except either rofecoxib or celecoxib is given instead of indomethacin. Both of these drugs are also non-steroidal anti-inflammatory drugs that inhibit prostaglandin production. Unlike indomethacin, rofecoxib and celecoxib are given orally instead of through a vein, so, to allow time for the drug to be absorbed, the second scan is delayed for 2 hours. Functional activation (indomethacin): This study is done in two parts. In both parts, a MRI brain scan is done. During the study, the subject performs a simple motor task, such as finger tapping. For the second part of the study, indomethacin is injected through a catheter in an arm vein. Functional activation (rofecoxib and celecoxib): This study is identical to the indomethacin functional activation study, except either rofecoxib or celecoxib is given instead of indomethacin. Because they are given orally instead of through a vein, the second scan is delayed 2 hours to allow time for the drug to be absorbed.
This study will evaluate magnetic resonance imaging (MRI ) methods for measuring changes in the brain's blood flow during hypercapnia (a condition of excess carbon dioxide in the blood). MRI is a diagnostic tool that uses a large magnet and radio waves to produce images of the body without X-rays. Healthy normal volunteers in this study may have as many as six MRI scans over a 2-year period. For this procedure, the person lies on a stretcher placed in a strong magnetic field produced by the MRI machine. During the scan, the person's blood carbon dioxide (CO2 ) levels will be increased either by: 1) breathing air mixtures containing up to 5% CO2; or 2) receiving an intravenous (I.V.) injection of a drug called acetazolamide. Persons who breathe CO2 will have their heart rate, blood pressure and oxygen levels monitored throughout the procedure. Those receiving acetazolamide will have the drug injected intravenously (I.V.) into an arm vein. If the volunteer experiences any unpleasant side effects from the CO2 or acetazolamide, the study will be stopped. The information gained from this study will be used to develop better ways to study brain function, possibly leading to better diagnostic and treatment methods.