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)

The purpose of this study was to assess the relationship between the breathing pattern response to CO2 and the severity of mechanical impairment in twenty patients with COLD. The CO2 response was compared to that of a control group of twelve normal subjects. All patients had airway obstruction (FEV1 = 40 +/- 14% of predicted; means +/- SD) and hyperinflation (FRC = 154 +/- 23% of predicted). Tidal volume (VT), inspiratory and total cycle duration (TI, TT), occlusion pressure (P0.1) and endtidal PCO2 were measured at rest and during hyperoxic CO2 rebreathing. On the same day, in all patients, arterial blood gas analysis, spirometric and plethysmographic measurements were made. The slope (S) of the P0.1 response (SP 0.1) to increasing endtidal PCO2 was negatively correlated with airway resistance (r = -0.59; p less than 0.01). Although the flow response, S(VT/TI), was positively and closely correlated with SP 0.1 (r = 0.88; p less than 0.001), it also appeared to be independently influenced by obstruction (p less than 0.01). The tidal volume response, SVT, was principally correlated with inspiratory capacity (r = 0.90; p less than 0.001) and also, independently, with Vmax50 (p less than 0.01). SVT was diminished in seventeen patients, ten of whom only had a decreased S(VT/TI). The shortening in TI during hypercapnia was most marked in patients with the greatest S(P0.1), who did not have arterial hypercapnia at rest. These results suggest: that the poor VT response to CO2 in COLD patients is principally caused by a limitation in inspiratory volume expansion.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Role of the mechanical impairment on the ventilatory response to CO2 in chronic airway obstruction. 310 31

In an attempt to narrow the definition of normal ventilatory response to hypercapnia (SVE), we studied 105 healthy Caucasians, aged from 18 to 80 years and living at sea level. The mean and SD of SVE were 2.18 +/- 0.77 1 X min-1 X mmHg-1 in males and 1.70 +/- 0.74 in females, narrower than the ranges previously reported. The 95% tolerance limits were 0.491-3.735 and 0.241-2.963 respectively. SVE was correlated with height, body surface area, static and dynamic lung volumes (p less than 0.01), age and weight (p less than 0.05). A prediction formula for SVE was derived on the basis of FEV1, which of the above parameters best correlated with SVE. The separate measurement of the tidal volume and frequency changes (SVT, Sf and SVT/Sf) showed that the SVT and SVT/Sf were significantly higher in males than in females even after adjustment for lung volume (p less than 0.01 and p less than 0.02 respectively), suggesting a different pattern of response to hypercapnia between the sexes.
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PMID:Ventilatory response and pattern of breathing during hypercapnia. 369 40

CASE DESCRIPTION 4 dogs were examined because of pleural effusion and ventricular tachycardia, coughing and supraventricular tachycardia, appendicular osteosarcoma, and syncopal episodes. CLINICAL FINDINGS In all 4 dogs, a heart base tumor was identified by means of thoracic CT. TREATMENT AND OUTCOME In all 4 dogs, the heart base tumors were treated by means of stereotactic body radiation therapy. Dogs were anesthetized, and neuromuscular blockade was achieved with atracurium or vecuronium. A circle rebreathing system with 15 m (50 feet) of anesthetic tubing coursing through the vault wall was used to connect the patient to the anesthesia machine, which was located in the control room. After a brief period of hyperventilation, an inspiratory breath was held at 20 cm H2O for the duration of beam delivery. Each beam delivery lasted between 30 and 100 seconds. Immediately following the breath hold, assisted ventilation was resumed. Mean treatment delivery time for each patient was 26 minutes; mean total anesthesia time was 89 minutes. All patients recovered without complications. There was no evidence of hemoglobin desaturation or hypercapnia during the anesthetic procedure. CLINICAL RELEVANCE The technique allowed for control of the respiration cycle from outside the radiation vault and a short overall treatment time. No adverse effects were encountered. This procedure should be considered when delivering radiation to structures within the thoracic cavity.
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PMID:Neuromuscular blockade and inspiratory breath hold during stereotactic body radiation therapy for treatment of heart base tumors in four dogs. 2805 56