Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Static compliance of the total respiratory system is decreased during anesthesia, 2. The fall in total static compliance is probably caused by a fall in lung compliance. 3. It seems unlikely that the fall in lung compliance is the primary event. The change in pleural pressures at FRC before and during anesthesia would answer this question, but the data are conflicting. 4. It is more likely that the position of the chest wall pressure-volume curve shifts to the right as a consequence of anesthesia, so that the position of equilibrium for the lung and chest wall at FRC is at a lower volume. The alteration in the chest wall is possibly because of loss of respiratory muscle tone. 5. FRC is reduced. Gas trapping occurs as a secondary event if FRC falls to below CC. 6. Lung compliance falls as a consequence of the fall in FRC, but only if FRC drops below CC, and closure occurs. No data of the correlation of change in lung compliance to the relationship of FRC to CC have been published. 7. A-aDo2 increases because of an increase in the amount of lung where ventilation is reduced compared to perfusion. Areas of zero ventilation (shunt) will also be produced. 8. The changes in lung compliance, FRC, and A-aDo2 appear to have similar characteristics. They are not influenced by depth or type of general anesthesia or the presence of neuromuscular blockade. They appear as soon as anesthesia is induced and are not progressive with time during anesthesia. They are less in the sitting position and in taller, thinner subjects. They appear to be only transiently affected by hyperinflations. 9. The fall in total respiratory system compliance may contribute to the apparent depression of the ventilatory response to carbon dioxide.
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PMID:The mechanical properties of the respiratory system during anesthesia. 85 30

Buprenorphine is a potent synthetic opioid-partial antagonist analgesic drug currently under clinical trial. When administered intravenously to human volunteers buprenorphine produced a significant depression of the ventilatory response to carbon dioxide stimulus for a period in excess of six hours.
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PMID:Effect of buprenorphine on the ventilatory response to carbon dioxide. 86 56

Growth rate, plasma amino acid, and alpha-keto acid concentrations and activities of the branched-chain amino acid degradative enzymes of rats were measured. Effects of ingestion of excessive amounts of branched-chain amino acids on these variables were determined. Excessive intake of a single branched-chain amino acid led rapidly to elevated plasma concentration of both the amino acid administered and its corresponding alpha-keto acid and, if the rats had previously been fed a low protein diet, to an increase in liver branched-chain alpha-keto acid dehydrogenase activity. Only leucine caused, in addition, marked growth and food intake depression and decreased plasma isoleucine, valine, alpha-keto-beta-methylvaleric acid and alpha-keto isovaleric acid concentrations. The growth depression was associated food intake depression and could be moderated by addition of isoleucine and valine to the diet. The decreases in plasma isoleucine, valine, alpha-keto-beta-methylvaleric acid and alpha-keto isovaleric acid were not caused by increased degradation of these metabolites to carbon dioxide as branched-chain amino acid oxidation rates in vivo were unchanged by leucine loading and the degradative enzymes were unchanged in adequately fed rats. The decreased concentrations of these amino and keto acids may be the result of decreased protein degradation or increased protein synthesis, possibly mediated by insulin.
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PMID:Effects of branched-chain amino acid antagonism in the rat on tissue amino acid and keto acid concentrations. 87 Jun 54

The purpose of this investigation was to determine the value of ventilatory measurements and Apgar score in the diagnosis of respiratory depression in the newborn infant. The following were the results of the determinations made in 24 neonates whose mothers had received meperidine in a total dose up to 3 mg/kg within three hours prior to delivery; Respiratory rate, 51+/-3.7/minute; tidal volume, 21.4 +/- 1.5 ml; minute ventilation, 339 +/- 24 ml/kg X minute; end tidal CO2, 40.8 +/- 1.3 mm Hg; ventilatory response to CO2, 21.8 +/- 2.7 ML/KG X minute X mm Hg PACO2. The mean Apgar score was 7.1 and 9.0 at 1 and 5 minutes, respectively. None of the determinations were indicative of respiratory depression with the exception of the slope of the CO2 response curve; it was considered to be below the normal range. No correlations existed between the CO2 response curve and any other values. It is concluded that meperidine administered to mothers in labor in the described dose will not significantly alter Apgar score, VE, VT, RR, AND PAco2 in the newborn infant. The extent of respiratory center depression could be determined only by the decreased ventilatory response to CO2.
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PMID:Respiratory depression at birth--value of Apgar score and ventilatory measurements in its detection. 87 Jun 60

Enflurane anesthesia with thiamylal induction in the dog produced only slight, statistically insignificant, changes in the heart rate and the mean systemic blood pressure. A significant depression of the respiratory rate with an associated significant increase in the arterial partial pressure of CO2 was produced, accompanied by a decrease in the blood pH. Progressive drop of the body temperature occurred throughout anesthesia. Significant hematologic changes included a reduction in the packed cell volume and the erythrocyte and leukocyte counts. The only significant change in the blood chemistry was an increase in alkaline phosphatase at 24 and 48 hours after induction of anesthesia.
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PMID:Physiologic changes in the dog anesthetized with thiamylal and enflurane. 87 63

Multiple serum chemical values were examined in 92 patients with chronic glaucoma who were treated with the carbonic anhydrase inhibitors (CAIs) acetazolamide or methazolamide, seeking relationships between serum composition and symptomatic side effects. Of the 92 patients, 44 complained of a symptom-complex of malaise, fatigue, weight loss, depression, anorexia, and loss of libido, which we have found most commonly to threaten continuation of therapy. Patients who had this symptom complex were significantly more acidotic than those without it. Ten of 24 patients who had chemical evidence of excessive acidosis reported a dramatic alleviation of symptoms when sodium bicarbonate was administered, although their serum CO2-combining power changed little. There was no correlation of the symptom complex with serum potassium concentration, except in a few patients who were simultaneously receiving chlorothiazide diuretics for systemic hypertension and who became frankly hypokalemic.
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PMID:Carbonic anhydrase inhibitor side effects. Serum chemical analysis. 88 13

The ventilatory response to CO2 was subdivided into that portion due to increasing rib cage expansion, and that due to increased diaphragmatic descent. Five children were studied, awake, and anesthetized with halothane, 0.8-0.9%. During anesthesia there was a 67+/-8% reduction (mean+/-SE) in the slope of the response of overall ventilation to an increase in CO2. This was primarily due to an 89+/-8% reduction in the recruitment of rib cage ventilation (P less than .001). There was no significant change in the slope of the diaphragmatic response (anesthetized value 19+/-21% less than control), although the response curve was shifted to the right so that a higher CO2 concentration was needed to stimulate a given level of diaphragmatic excursion. Additional measurements of the inspiratory intercostal electromyogram in three adult subjects documented a rapid, profound depression of intercostal activity with halothane anesthesia that was associated with a marked decrease in rib cage ventilation. The authors conclude that a major component of the ventilatory depression associated with halothane anesthesia results from the preferential suppression of intercostal muscle function with relative sparing of diaphragmatic activity.
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PMID:Contributions of changing rib cage--diaphragm interactions to the ventilatory depression of halothane anesthesia. 90 May 41

In postoperative patients one frequently observes respiratory difficulty in excess of what is indicated by physical alterations in respiratory mechanics. This would suggest that some patients lack normal compensatory mechanisms which respond to mechanical changes in the lung. It is entirely possible that inadequacy of compensatory mechanisms is present before surgery and predisposes patients to respiratory distress. In the clinical environment elaborate testing is precluded by the physical status of the patients. Thus, a noninvasive procedure has been designed to apply stress to the respiratory system in order to study the effect of stress at increasing levels of CO2. In this test a subject's respiration is measured as he rebreathes a mixture of 7% CO2 and 93% O2 from a closed system. On successive trials, fixed pressure inspiratory threshold loads are applied in sequence. With this type of load the increased work required to inspire a given volume depends only on the increased inspiratory pressure. In most normal subjects CO2 response was incrementally depressed when threshold loads were introduced. Patients with brain stem lesions showed a greater depression at higher loads. This may indicate a reduced ability to tolerate increased loads to breathing.
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PMID:Ventilatory responses to threshold loaded respiration in man. 90 Jun 46

This study compares the inotropic action of morphine sulfate and ketamine hydrochloride on isolated canine right ventricular trabeculae. The heart was removed from 19 mongrel puppies weighing 5 to 9 kilograms and placed in Krebs-Ringer bicarbonate solution. The bathing solution contained 1.3 mM. of Ca2+ and was bubbled with a gas mixture of 95 per cent oxygen and 5 per cent carbon dioxide. At Lmax (i.e., the peak of isometric force-length curve) morphine even in large concentrations (up to 1 mg. per milliter) produced no significant direct inotropic effect. At the lower concentrations tested there was a minor but not significant increase in contractile performance, whereas at the highest concentration used there was a minor but not significant depression in contractility. In these same muscles lower concentrations of ketamine had a significant positive inotropic action, but a concentration of 200 mug per milliliter, which is approximately equimolecular to 1 mg. per milliliter of morphine sulfate, caused a profound depression in contractile performance. In the presence of a beta-blocking agent and in reserpine-pretreated muscles, low concentrations of ketamine, which had only a positive inotropic action in the normal muscles, now caused depression of contractile performance. The positive inotropic action of ketamine is thus indirect and mediated via adrenergic influences. At each concentration studied the direct inotropic action of ketamine was exclusively negative. Because of this bimodal inotropic action seen when adrenergic mechanisms are intact, we conclude that caution must be exercised when ketamine is given to patients previously treated or still under the influence of drugs having adrenolytic properties. Caution is also necessary when ketamine is used in patients having diminished cardiac adrenergic reserves as in congestive heart failure.
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PMID:Comparison of the inotropic action of morphine and ketamine studied in canine cardiac muscle. 93 49

In 20 patients undergoing a rhinoplasty or rhytidectomy under local anesthesia combined with intravenous sedatives and hypnotics, fairly satisfactory operating conditions were obtained. This technique was associated with respiratory depression and hypoxia, however, with statistically significant elevations in the arterial carbon dioxide tensions, and depressions in the arterial oxygen tensions. We now advocate the routine use of supplement oxygen and periodic deep breathing during the operation, and in the immediate postoperative period. We will continue to advise the use of general anesthesia in patients with cardiopulmonary disease. The mental detachment and inability to articulate discomfort during the procedure are major disadvantages to the use of fentanyl and droperidol in these patients.
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PMID:Blood gas and hemodynamic effects of sedatives and analgesics when used as a supplement to local anesthesia in plastic surgery. 93 76


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