Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Midazolam at sedative doses induces an increase in upper airway resistance, but its effects on the work of breathing have not been established. The flow-resistive work of breathing and pulmonary resistance (RL) of eight healthy volunteers were measured, with either midazolam 0.1 mg/kg or placebo in a random order. Esophageal pressures were measured using a balloon-tipped catheter, airflow using a pneumotachograph. Total resistive work expressed per minute (WTOT) and per liter of ventilation (WTOT/VE), and their inspiratory (WI) and expiratory (WE) components were determined. No change was observed after placebo injection. Five minutes after midazolam injection, an increase was observed in WTOT (from 3 +/- 0.4 J/min [mean +/- SEM] at control to 6.3 +/- 1.1 J/min; P < 0.01) and in WTOT/VE (from 360 +/- 30 mJ/L at control to 1250 +/- 120 mJ/L; P < 0.01), involving both WI and WE components. An increased inspiratory RL was observed from 13.7 +/- 2.6 cm H2O.L-1.s-1 at control to 32.8 +/- 3.9 cm H2O.L-1.s-1 after midazolam. Changes in inspiratory RL were correlated to changes in WI and WI/VE (r = 0.574, P < 0.001; and r = 0.762, P < 0.001, respectively). Our results suggest that airway obstruction plays a major role in the increased work of breathing observed during sedation with midazolam.
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PMID:Effects of intravenous midazolam on the work of breathing. 806 64

Motilin induces phase III activity of the gastrointestinal tract. Erythromycin has a motilin-like effect on the stomach and significantly increases the lower esophageal sphincter (LES) pressure in normal volunteers. This investigation was performed to evaluate the effects of erythromycin on esophageal function in patients with gastroesophageal reflux disease (GERD). Esophageal manometry was performed in 10 GERD patients before and after intravenous infusion of 500 mg of erythromycin. Values are expressed as mean +/- SEM. LES pressure increased from 13.9 +/- 2.9 mm Hg at baseline to 28.9 +/- 3.6 mm Hg after infusion of erythromycin (p < 0.01). The duration of contractions in the proximal, middle, and distal esophagus was significantly prolonged from 3.5 +/- 0.4 seconds, 3.8 +/- 0.4 seconds, and 4.1 +/- 0.5 seconds to 4.2 +/- 0.2 seconds, 4.6 +/- 0.5 seconds, and 5.6 +/- 0.6 seconds, respectively, after infusion of erythromycin (p < 0.05 for each comparison). Erythromycin did not effect esophageal body contraction amplitude or velocity, or the upper esophageal sphincter. Serum motilin decreased slightly after the administration of erythromycin. We concluded the following: (1) Erythromycin profoundly stimulates the defective LES in patients with GERD. This appears to be a direct motilin agonist-like effect rather than being mediated by release of endogenous motilin. (2) Erythromycin has less effect on the esophageal body, although it does prolong the duration of esophageal contractions.
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PMID:Erythromycin strengthens the defective lower esophageal sphincter in patients with gastroesophageal reflux disease. 831 Nov 29

Whether the oesophageal motor response to reflux, as recorded over 24 hours, is impaired in patients with reflux oesophagitis was investigated. Twenty three patients with oesophagitis (Savary-Miller grades I-IV) and 23 control subjects matched for age and sex underwent 24 hour ambulatory pH and pressure monitoring. All contractions occurring in the 2 minute period after the onset of each reflux episode were analysed automatically using dedicated computer algorithms. A total of 2085 reflux episodes occurred--1513 in patients and 572 in controls. Oesophageal acid exposure was greater (p < 0.01) in patients than in controls (mean (SEM) % time pH < 4 13.3 (1.7) and 5.3 (0.9)%, respectively). The mean duration of the supine reflux episodes was longer (p < 0.01) in patients (11.2 (2.8) minutes) than in controls (5.1 (1.8) minutes). In the upright period, no significant differences in the motor response to reflux were found. In the supine period, the patients showed a higher number of reflux induced contractions (4.40 (0.61) v 1.62 (0.31), p < 0.01), a higher contraction amplitude (4.55 (0.42) v 2.99 (0.71) kPa, p < 0.02) and longer contractions (1.86 (0.19) v 1.32 (0.29) seconds, p < 0.05). The percentages of peristaltic and simultaneous contractions that occurred in response to supine reflux did not differ between the two groups. In patients with reflux oesophagitis the motor response of the oesophagus to reflux is not impaired. During the supine period the response is even stronger than in healthy controls.
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PMID:Oesophageal motor response to reflux is not impaired in reflux oesophagitis. 847 77

We have used an oesophageal Doppler to measure aortic blood flow velocity before, during and after induction of carbon dioxide pneumoperitoneum in 10 consecutive patients, mean age 58 yr, undergoing laparoscopic hernia repair. Derived values for stroke distance, minute distance and systemic vascular resistance showed considerable interpatient variation indicating unpredictable haemodynamic responses. Five minutes after insufflation of the abdomen there was a significant increase in mean arterial pressure from 82.5 to 103.6 mm Hg (P < 0.05) but both stroke distance and minute distance decreased significantly (mean 12.0 (SEM 1.4) cm to 9.0 (0.7) cm, P < 0.05; and 747.5 (82) cm min-1 to 596 (49) cm min-1, P < 0.05; respectively) indicating a significant decrease in cardiac output. There was a corresponding increase in the index of systemic vascular resistance from 1092 (747) to 2079 (400) (P < 0.05) which persisted after deflation of the abdomen. Oesophageal Doppler can provide continuous online haemodynamic data with a rapid response to acute changes and may have a role in non-invasive haemodynamic monitoring during laparoscopic procedures in older patients with cardiovascular disease.
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PMID:Assessment of cardiovascular changes during laparoscopic hernia repair using oesophageal Doppler. 917 64

The forced oscillation technique (FOT) is a noninvasive method to measure respiratory resistance (Rrs) potentially useful for monitoring upper airway obstruction in patients with obstructive sleep apnea/hypopnea syndrome (SAHS). The aim of this work was to test the clinical suitability of FOT in assessing dynamic changes in airflow obstruction in patients with SAHS during continuous positive airway pressure (CPAP) and to investigate the CPAP dependence of Rrs. Forced oscillation (5 Hz) was applied to six male patients with SAHS submitted to CPAP titration procedure. Esophageal pressure was measured with a balloon-tipped catheter. Mid-inspiratory resistance (Rrs,i), mid-expiratory resistance (Rrs,e), and esophageal pressure swings (deltaPes) were computed for the respiratory events recorded at each CPAP level. Rrs,i decreased markedly and significantly from 36.0 +/- 4.0 cm H2O x s/L (mean +/- SEM) at baseline CPAP (4 cm H2O) to 13.1 +/- 2.8 cm H2O x s/L at optimal CPAP (11.3 +/- 0.4 cm H2O). Rrs,e showed a faster decrease with increasing CPAP reaching normal values at approximately 8 cm H2O. Rrs,i was strongly correlated (r2 = 0.94) with deltaPes. Our results suggest that FOT can be used as an alternative to the esophageal balloon for assessing airflow obstruction in patients with SAHS and for CPAP titration. Moreover, FOT allows us to detect phasic changes in resistance within the breathing cycle.
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PMID:Assessment of airflow obstruction during CPAP by means of forced oscillation in patients with sleep apnea. 960 33

The ability of the 'alkaline' components of reflux to cause harm in vivo is still open to debate, although these components have been shown in vitro to be capable of damaging the mucosa. The precipitation of bile acids and lysolecithin that occurs at low pH values is the main reason for questioning in vivo mucosal damage. This study was undertaken to determine the composition of gastric aspirates at different original pH values and the degree of solubility of the alkaline components when pH modifications are artificially induced. The samples for chemical analysis were collected from indwelling nasogastric tubes after surgical procedures that did not involve the upper gastrointestinal tract. Bile acid and lysolecithin concentrations were assessed by means of dedicated methods. Thirty-five samples were available for bile acid evaluation and 27 for lysolecithin evaluation. Bile acid and lysolecithin assessments were repeated after pH adjustment at 2, 3.5, 5.5 and 7. For easier assessment of the results, three ranges of the original pH were selected (pH < 2, 2 < or = pH < 5, pH > or = 5). For each pH range, results were pooled together and compared with those in the other pH ranges. Bile acid concentrations were 113+/-48, 339+/-90 and 900+/-303 (mean +/- s.e.m. micromol/L), respectively, in the three groups selected on account of the different original pH values. Differences were significant (p < 0.001). Both taurine- and glycine-conjugated bile acids were represented even at pH < 2. No major differences were observed in bile acid concentration with the artificially induced pH variations. Lysolecithin concentrations were 5.99+/-3.27, 30.80+/-8.43 and 108.37+/-22.17 (mean +/- SEM microg/ml), respectively, in the three groups selected on account of the different original pH ranges. Differences were significant (p < 0.001). No significant differences in lysolecithin concentration were detected with the artificially induced pH variations. In conclusion, both bile acids and lysolecithin are naturally represented in the gastric environment even at very low pH values, although their concentrations decrease on lowering of the naturally occurring pH. Given the concentration variability of bile acids and lysolecithin, further studies are needed to assess the minimal concentration capable of mucosal damage in vivo.
Dis Esophagus 2000
PMID:Reflux and pH: 'alkaline' components are not neutralized by gastric pH variations. 1100 32


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