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)

We examined the ability of capnometry and pulse oximetry to identify potential respiratory problems by comparing oxyhemoglobin saturation (O2Sat) as measured by pulse oximetry and end-tidal CO2 (PetCO2) with arterial blood gas (ABG) determinations in 40 mechanically ventilated ICU patients. Hemoglobin saturation as measured by pulse oximetry correlated significantly with PaO2 (r = .65, p less than .0001); more importantly, an oximeter O2 Sat less than 95% showed 100% sensitivity in identifying hypoxemia (i.e., PaO2 less than 70 torr). PetCO2 tended to correlate strongly with PaCO2 for individual patients, but not when evaluated as a screening tool for identifying ventilatory abnormalities in the overall group (r = .52, p less than .0001). A PetCO2 less than 26 torr identified hypocarbia (defined as PaCO2 less than 30 torr) with a sensitivity of 85%. However, a PetCO2 of greater than 40 torr predicted hypercarbia (PaCO2 greater than 45 torr) with a sensitivity of only 28%. The efficacy of pulse oximetry and capnometry in monitoring respiratory status during postoperative ventilatory weaning was examined in a subset of 24 patients who had undergone elective cardiac surgery. All patients were weaned by intermittent mandatory ventilation, but each was assigned randomly to either a control group monitored with periodic ABG sampling or to an experimental group, monitored by following PetCO2 and O2 Sat via pulse oximetry. In the experimental group, ABG values were obtained on ICU admission, but thereafter only if a) O2 Sat less than 95%, b) PetCO2 less than 26 or greater than 40 torr, or c) felt to be clinically indicated by ICU staff.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Efficacy of pulse oximetry and capnometry in postoperative ventilatory weaning. 313 Oct 68

With airway obstruction there is a decrease in inspiratory intrathoracic pressure. This could lead to increased venous return to the right ventricle (RV) and increased afterload imposed on the left ventricle (LV). Chronic upper airway obstruction, caused by either upper airway lesions or obstructive sleep apnea, is a cause of congestive heart failure because of a chronic resistive load imposed on the respiratory system. To determine the effects of chronic upper airway obstruction on RV and LV in adolescent rats, we chronically obstructed the trachea so as to considerably increased inspiratory esophageal pressure excursion (-3.7 +/- 2.2 to -29.4 +/- 10.1 cm H2O). Rats were studied at 7 wk (Group 1) and at 1 yr (Group 2) after tracheal banding. Sham-operated time-matched rats served as controls. In neither group was there evidence of arterial hypoxemia, but in both groups there was chronic hypercapnia (PCO2, approximately 51 mm Hg; bicarbonate, 27 to 28 mEq/ml). Hemoglobin was also normal in both groups, confirming the absence of chronic hypoxia. There were no significant differences between obstructed and control rats in lung, liver, and LV weight to body weight ratio. However, RV weight to body weight ratio was increased in obstructed rats compared with that in control rats in both groups by approximately 50% (p < 0.005). Thus, chronic normoxic airway obstruction leads to evidence of RV but not LV hypertrophy. We conclude that the mechanical effects of airway obstruction impose a chronically increased afterload on the RV, probably caused by venous return effects, but they have relatively little effect on the LV.
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PMID:Chronic upper airway obstruction produces right but not left ventricular hypertrophy in rats. 823 74

Children with congenital central hypoventilation syndrome (CCHS) lack normal awake ventilatory responses to hypoxia and hypercarbia, yet engage in daily activities typical of similarly aged children. Our patients with CCHS are assessed annually with a walking treadmill protocol to assess physiologic responses to different levels of simulated daily activity. We hypothesized that children with CCHS (compared with age- and sex-matched healthy controls) would 1) exercise for shorter durations and reach lower peak speed and incline on the treadmill; 2) become more hypoxemic, more hypercarbic, and develop less tachycardia during activity; and 3) take longer to return to baseline oxygenation, ventilation, and heart rate than normal children. Seven children with CCHS [mean age, 6.9 +/- 3.0 (SD) years] who required 24 h/day ventilatory support (diaphragm pacers while awake and mechanical ventilation asleep) and 7 controls performed a walking protocol on a treadmill with progressive increments in speed and incline. Hemoglobin saturations (SaO2), end-tidal carbon dioxide concentrations (ETCO2), and heart rates (HR) were recorded at baseline conditions, during activity and during recovery. There were no significant differences between children with CCHS and controls in baseline values, duration of activity, peak speed, and incline achieved during walking and recovery time to baseline once the treadmill had stopped. However, children with CCHS became significantly more hypoxemic and hypercarbic during activity (P < 0.05), and they had a lower percent increase in HR during treadmill walking than controls (P < 0.05). These results offer the clinician an opportunity to adjust clinical management in children with CCHS by providing specific recommendations to parents about appropriate levels of activity for their children with CCHS.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Congenital central hypoventilation syndrome: cardiorespiratory responses to moderate exercise, simulating daily activity. 857 Mar 8

The aim of this study is to investigate if erythrocyte fragility is altered in chronic obstructive pulmonary disease (COPD) due to oxidative stress. Fasting blood samples were collected into both plain tubes and tubes with K(3) EDTA and analyzed in two hours for hematologic indexes and erythrocyte osmotic fragility (EOF). Malondialdehyde (MDA) concentrations in serum were detected in terms of TBARS (thiobarbituric acid reactive substances), spectrophotometrically. Thirty-nine clinically stable male COPD patients with mean age 67+/-8 were prospectively studied. The control subjects consisted of healthy males with mean age 64+/-12. Pulmonary function tests of COPD patients revealed severe airway obstruction whereas they were normal for control group. Normal pH with mild hypoxemia and hypercapnia were detected in arterial blood gas analyses. Hemoglobin, haematocrit and mean corpuscular volume values of two groups were similar. Mean serum MDA concentration was 1.09+/-0.11 micromol/l in COPD patients and 0.95+/-0.06 micromol/l in the control group (p=0.336). EOF was 33.06+/-1.24% in COPD group and 33.17+/-1.55% in controls (p=0.453). There was no correlation between EOF and MDA concentrations of COPD patients (r=-0.18, p=0.924). EOF and MDA did not correlate with severity of COPD (p>0.05). We conclude that markers of oxidative stress are not increased and erythrocyte osmotic fragility is not altered in stable COPD patients with normal arterial pH.
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PMID:Erythrocyte fragility is not altered in stable chronic obstructive pulmonary disease with normal arterial pH. 1265 16