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

The clinical effects of a propofol-alfentanil association were studied in fifteen patients ASA II (mean age 50.1 +/- 14.1) anaesthetized for E.N.T. endoscopy after informed consent. All the patients received an intramuscular premedication with 0.10 to 0.15 mg.kg-1 midazolam. Propofol 2.5 mg.kg-1 was injected in a peripheral venous line with alfentanil 10 micrograms.kg-1, followed by continuous automatic injection of propofol at a dose of 5 to 10 mg.kg.h-1 and alfentanil 5 micrograms.kg-1 given just before suspension. After induction and during maintenance of anaesthesia, the patients were allowed to breathe oxygen spontaneously O2 assisted when apneic. The following variables were studied before induction (to), after induction (t1), during suspension (t2) and when stopping the infusion (t3): haemodynamic parameters using an invasive method and blood gases. Statistical analysis was performed using the Student's test for paired samples. Surgical conditions and anaesthetic quality were good with early recovery of consciousness and return of all reflexes. After an initial period of cardio vascular depression, the haemodynamic parameters did not vary much during the anaesthesia and propofol-alfentanil appeared to limit considerably the hypertension due to laryngoscopy. However, there was a moderate degree of hypercapnia (p less than 0.001) in most patients, giving evidence of some respiratory depression and possibly a greater depth of anaesthesia than desirable. Indeed, the doses of alfentanil required seemed to be more important with propofol because of a probably interference between the two drugs; the doses of these drugs should therefore be modified according to the length of surgery.
 ...
PMID:[Circulatory and respiratory repercussions to direct suspension laryngoscopy in the adult: value of a propofol-alfentanil combination]. 249 72

Compensation for inspiratory flow-resistive loading was compared during progressive hypercapnia and incremental exercise to determine the effect of changing the background ventilatory stimulus and to assess the influence of the interindividual variability of the unloaded CO2 response on evaluation of load compensation in normal subjects. During progressive hypercapnia, ventilatory response was incompletely defended with loading (mean unloaded delta VE/delta PCO2 = 3.02 +/- 2.29, loaded = 1.60 +/- 0.67 1.min-1.Torr-1 CO2, where VE is minute ventilation and PCO2 is CO2 partial pressure; P less than 0.01). Furthermore the degree of defense of ventilation with loading was inversely correlated with the magnitude of the unloaded CO2 response. During exercise, loading produced no depression in ventilatory response (mean delta VE/delta VCO2 unloaded = 20.5 +/- 1.9, loaded = 19.2 +/- 2.5 l.min-1.l-1.min-1 CO2 where VCO is CO2 production; P = NS), and no relationship was demonstrated between degree of defense of the exercise ventilatory response and the unloaded CO2 response. Differences in load compensation during CO2 rebreathing and exercise suggest the presence of independent ventilatory control mechanisms in these states. The type of background ventilatory stimulus should therefore be considered in load compensation assessment.
 ...
PMID:Background ventilatory stimulus as a determinant of load compensation. 249 94

The ocular hypertension caused by the mu agonist alfentanil (10 micrograms/kg, i.v.) in spontaneously breathing rabbits was reversed to ocular hypotension by pretreatment with the kappa agonist-mu antagonist, nalbuphine (0.6 mg/kg, i.v.). This is probably due to nalbuphine's mu antagonistic action which prevents the respiratory-depressant effect of alfentanil that elevates the blood pCO2 with a drop in blood pH. It is known that hypoxia and hypercarbia lead to uveal vasodilation and increase in aqueous production which cause elevation of intraocular pressure. Both alfentanil and nalbuphine have miotic effects when used individually. However, no further reduction in the pupil size was noted by their combined use. These results indicate that using nalbuphine and alfentanil together may be considered a safe combination for eye surgery because it preserves the analgesic effect of either drug while prevents the undesirable respiratory-center depression and the ocular hypertension observed with alfentanil alone.
 ...
PMID:Interaction between nalbuphine and alfentanil on intraocular pressure and pupil size of conscious rabbits. 249 54

The effects of mild hypocapnia (PaCO2 22 mm Hg) and hypercapnia (PaCO2 59 mm Hg) on the splanchnic circulation and hepatic function were studied in six pentobarbital anesthetized, laparotomized, mechanically ventilated beagles. Tidal volume and respiratory frequency were held constant throughout the measurements. Hepatic artery blood flow (HABF) and portal vein blood flow (PVBF) were measured by electromagnetic flowmeters. Hepatic function was assessed by indocyanine green (ICG) elimination kinetic analysis after intravenous injection of the dye. Hypocapnia caused a decrease in HABF without affecting the systemic circulation. Hypercapnia, on the other hand, caused a significant increase in cardiac output without changing mean arterial pressure. There was a significant increase in PVBF and total hepatic blood flow (THBF = PVBF + HABF). Despite the increases in PVBF and THBF, the half-life of ICG was significantly longer during hypercapnia (9.09 +/- 0.79 min) than during hypocapnia (7.16 +/- 0.37 min), and plasma ICG clearance was smaller during hypercapnia (4.79 +/- 0.44 ml.min-1) than during hypocapnia (5.44 +/- 0.33 ml.min-1) or normocapnia (5.27 +/- 0.50 ml.min-1), indicating the depressed hepatic function during hypercapnia. We conclude that mild hypocapnia decreases HABF without affecting hepatic function and that mild hypercapnia is associated with a depression of hepatic function in spite of the increases in PVBF and THBF.
 ...
PMID:Effects of hypocapnia and hypercapnia on splanchnic circulation and hepatic function in the beagle. 250 78

To assess the effect of cerebral blood flow on hypoxic ventilatory response in humans, internal jugular venous blood and arterial blood gases and ventilation were measured simultaneously and repeatedly in fifteen healthy male volunteers in two settings: 1) progressive and subsequent sustained isocapnic hypoxia (PetO2 = 45 Torr), and 2) stepwise and progressive hypercapnia. Jugular venous-arterial PCO2 difference decreased significantly from 8.7 Torr at control to 7.4 Torr at 1 min, and 6.4 Torr at 5 and 15 min of sustained hypoxia, probably due to the increase in cerebral blood flow. Corrected hypoxic ventilatory response (HVR) (1.27 +/- 0.75 1/min/%), which was calculated with the product of change in jugular venous PCO2 (PjCO2) and the value of hypercapnic ventilatory response on PjCO2 (delta VE/delta PjCO2), was significantly higher than the actually measured HVR (0.52 +/- 0.45 1/min/%). However, the magnitude of this correction did not correlate with the original HVR. Ventilation decreased significantly during sustained hypoxia from 16.5 +/- 5.3 1/min at 1 min to 14.1 +/- 6.9 1/min (p less than 0.05) at 15 min of hypoxia. Such ventilatory depression was remarkable in the low responders, whose HVR were lower than the average response of all subjects. However, the behavior of PaO2 and PjCO2 did not seem to explain those results. Therefore, we conclude that an increase in cerebral blood flow may have a significant effect on HVR in humans even during moderate isocapnic hypoxia (PaO2 = 45 Torr), but it is unlikely to be the main factor of the inter-individual variation in HVR nor the ventilatory depression during sustained hypoxia.
 ...
PMID:[Effects of cerebral blood flow on hypoxic ventilatory response--a human study by jugular venous blood sampling]. 251 38

Thoracic epidural fentanyl has been used successfully for postoperative analgesia in patients undergoing thoracic surgery. Prior investigators have suggested that increasing the administered dosage and volume of lumbar epidural fentanyl may increase the spread of analgesia. The feasibility of injecting a high volume (20 mL) of fentanyl into the lumbar epidural space for post-thoracic surgery analgesia was studied in 17 patients undergoing elective thoracotomy or sternotomy. All patients had a lumbar epidural catheter placed before induction of general anesthesia. No narcotic was administered during surgery. Thirty minutes before the conclusion of anesthesia, 200 micrograms of fentanyl in 16 mL of 0.9% saline was administered via the epidural route. In the intensive care unit (ICU), additional fentanyl in the same dosage and volume was injected when the patient complained of pain. Pain was scored on a linear analog scale pre-injection and 30 minutes post-injection. Arterial blood gases were obtained simultaneously. All patients experienced pain relief within 15 minutes of injection. No significant respiratory depression or hypercarbia was noted. Lumbar epidural fentanyl is a safe and practical alternative to thoracic epidural analgesia in the post-thoracic surgical patient.
 ...
PMID:Lumbar epidural fentanyl analgesia after thoracic surgery. 251 38

The effect of intravenous sedation on oxygen saturation and ventilation was studied in 11 patients undergoing peritoneoscopy. Oxygen saturation (mean +/- SD) decreased from baseline (94.7% +/- 1.7%) to nadir (78.6% +/- 10.7%) after sedation. Respiratory depression was evident in these patients by concomitant decreases in minute ventilation and tidal volume. Baseline to nadir arterial blood gas changes in eight patients were consistent with hypoventilation and also suggested a superimposed ventilation perfusion mismatch. Mean respiratory rate did not significantly change during peritoneoscopy. Peritoneal gas insufflation stimulated increased ventilation and oxygen saturation, but no further changes in PCO2 or pH. We conclude that serious arterial oxygen desaturation and possibly some ventilation perfusion mismatch occur after sedation with intravenously administered meperidine-diazepam for peritoneoscopy with resultant hypoxemia, hypercarbia, and acidosis.
 ...
PMID:Alterations in oxygen saturation and ventilation after intravenous sedation for peritoneoscopy. 252 81

A bolus injection of almitrine bismesylate (0.5 mg.kg-1 i.v.) in anaesthetised artificially ventilated cats caused a significantly greater increase in carotid chemosensory discharge in animals with sectioned ipsilateral ganglioglomerular sympathetic nerves in comparison with a group in which these nerves were intact. Plasma levels of almitrine were similar in both groups. Responses to hypoxia and hypercapnia post-almitrine were also bigger if the ganglioglomerular nerves were cut. Domperidone (10-50 micrograms.kg-1 i.a), a dopamine D2 receptor antagonist, greatly increaed the responsiveness of chemoreceptors to almitrine in ganglioglomerular nerve-intact preparations. Almitrine-induced chemosensory activity was unaffected by illuminating the carotid bifurcation with light from a fibre optic lamp, regardless of whether or not the ganglioglomerular nerves were cut. It is concluded that almitrine may directly or indirectly activate an efferent pathway in the ganglioglomerular nerves to cause depression of chemoreceptor activity, possibly by releasing dopamine to act at D2 dopamine receptors in the carotid body.
 ...
PMID:Ganglioglomerular nerves influence responsiveness of cat carotid body chemoreceptors to almitrine. 252 5

The effects of subcutaneous doses of morphine and verapamil on respiratory and cardiovascular parameters have been assessed in conscious rats. Verapamil (10 mg kg-1) was injected simultaneously with morphine (16 mg kg-1) or at 10, 30, or 60 min before morphine administration. Morphine induced respiratory depression, as indicated by marked hypercapnia, hypoxia and acidosis, and caused marked tachycardia. Although morphine produced only a minor and inconsistent (but statistically significant, P less than 0.01) reduction of mean arterial blood pressure, morphine potentiated verapamil-induced hypotension. Verapamil suppressed morphine-induced hypercapnia only when injected simultaneously with morphine. Verapamil alone did not affect arterial blood gases or pH, but decreased heart rate and mean arterial blood pressure. Verapamil attenuated and delayed the maximum positive chronotropic effects of morphine at all times tested. Antagonism by verapamil of respiratory depression and tachycardia produced by morphine was unrelated to morphine levels in plasma. Thus, the explanation of verapamil-morphine interactions on respiration and cardiovascular function is not pharmacokinetic.
 ...
PMID:Time course of verapamil interaction with morphine effects on physiological parameters in rats. 257 6

The cardiovascular responses to breath-holding (BH) during short-lasting supramaximal exercise (415 W) on a cycle ergometer were investigated in 15 healthy male subjects. The arterial oxygen saturation, heart rate (HR), endtidal PO2 and PCO2 were continuously monitored. Firstly, 15 subjects performed exercise during BH, preceded by air breathing (air-BH test), and secondly, exercise without BH. Then 9 of the subjects performed the same procedure as in the air-BH test, except that all subjects breathed 100% O2 for 1 min before apnoea (O2-BH test). In 2 of these subjects, the systemic arterial blood pressure was continuously measured via a catheter in the radial artery and plasma catecholamine concentration [CA] was also measured both during the air-BH and the O2-BH tests. In the later period of the air-BH test, the high HR level became progressively depressed. This response, however, was absent in the O2-BH test. There was a late increase in the arterial blood pressure in both tests, and both tests produced hypercapnia. Only the air-BH test resulted in hypoxia, substantial hypertension and HR-depression. The increase in plasma CA was similar in both tests. The marked HR-depression demonstrated here is ascribed mainly to activation of the peripheral arterial chemoreceptors by asphyxia, and partially to baroreceptor activity due to elevated blood pressure.
 ...
PMID:Heart rate response to breath-holding during supramaximal exercise. 258 43


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>