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)

The anesthesiologist uses a wide spectrum of drugs, including inhalational general anesthetics, barbiturates, benzodiazepines, narcotics analgesics and their antagonists, and neuromuscular blocking drugs. All of these drugs in sufficient dose impair the ventilatory response to chemical stimuli, and may cause inadequate gas exchange. The effect of depression of ventilatory control depends on the magnitude of depression and the coexistence of functional abnormalities in the respiratory system. The functional abnormalities are the result of preexistent pulmonary disease or other disease processes that impair respiratory function, the anticipated effects of major surgery (e.g., pulmonary resection), and the complications of anesthesia and surgery. From a functional viewpoint, the mechanisms of the effects of these disease processes on ventilatory control are: (1) interference with the neurophysiological control of automatic ventilation; (2) impairment of peripheral or central chemoreceptor function; (3) impairment of respiratory muscle function; (4) increase in the mechanical load to breathing as a result of increased resistance or decreased compliance of the respiratory system; and (5) increase in the ventilatory requirements as a result of ventilation/blood flow maldistribution, metabolic acidosis, or increased metabolic rate. As a result of current trends in the use of multiple drugs and controlled ventilation during anesthesia, the patient is at greatest risk during the early postoperative period in the recovery room. In addition to the functional abnormalities described above, the probability of impaired gas exchange and respiratory failure is increased as a result of impaired metabolism and elimination of drugs as a result of hepatic and renal insufficiency, and acute changes in acidbase status, which alter the ionization and distribution of drugs.
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PMID:The effects of anesthetic drugs and disease on the chemical regulation of ventilation. 1 49

The study of the effect of analgesics in the newborn is difficult in the clinical situation and resort must be made to animals. Pethidine given within 1 hour of delivery is believed to cause less depression than when the time interval is longer. This study investigates whether it is pethidine or its metabolites which cause respiratory depression by comparing the respiratory effects of pethidine and its metabolites in the newborn rabbit. Fentanyl and buphrenorphine were also investigated as alternative analgesics. The response in the newborn rabbit to anoxia, is periods of dyspnoea, primary apnoea, and gasping. The metabolites of pethidine increased the primary apnoea signifying depression almost as much as pethidine. Depression was also produced when anoxia was induced 5 minutes after pethidine. Fentanyl caused less depression than pethidine or its metabolites excepting normeperidinic acid. Buphrenorphine administration resulted in the least depression with little difference between the low and high doses. Thus both pethidine and its metabolites are factors in the persisting depression, while buphrenorphine compared well with pethidine and fentanyl.
Anaesthesia 1977 Apr
PMID:The role of analgesics in respiratory depression: a rabbit model. 1 6

All potent CNS depressant drugs can depress cardiac function in man in a dose-dependent manner. The dose-effect curve is considerably flatter with several drugs (diethyl ether, cyclopropane, fluroxene, isoflurane, and ketamine), presumably from sympathetic nervous-system activation. Potent analgesics and tranquilizers appear to produce less depression, but have been incompletely studied. Neuromuscular blocking drugs and regional anesthesia produce minimal effects on the heart in healthy people. However, not as much is known about diseased man. For instance, nitrous oxide produces more depression in "muscle" function in IHD patients (43), while diazepam (28) and morphine (44) do not adversely affect pump function in this class of patients. Fluroxene (45) is more depressant in VHD patients, but nitrous oxide (46), morphine (30), fetanyl (46), and droperidol-fentanyl (46) seem to have equivalent effects to those seen in health patients. In any given patient, therefore, accurate prediction of the effect of any anesthetic drug on cardiac performance is not possible. Adequate monitoring and careful titration of drug dose offer the safest method of assuring a satisfactory response.
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PMID:Effect of anesthetic drugs on myocardial performance in man. 1 60

The cardiovascular effects of total hip placement were evaluated in 10 surgical patients, aged 55 to 82, while receiving fluroxene-N2O-O2 anesthesia. The anesthetic regimen caused mild cardiovascular depression. The placement of the acrylic cement into the acetabulum and femoral shaft also induced mild cardiovascular depression, but these changes were not significant at p less than 0.05. In one 67-yr-old woman, there were significant reductions of cardiac output and stroke volume 2 min after the insertion of acrylic into the femoral shaft, despite careful replacement of intravascular loss and careful anesthetic management. Methylmethacrylate (1 X 10(-6) to 1 X 10(-4), v/v) was administered to 24 isolated perfused rabbits hearts. These concentrations of methylmetacrylate are of the same order as measurable blood levels in surgical patients. There was a dose-dependent depression of left ventricular dP/dt correlated with a depression of the spontaneous heart rate. When the bradycardia was prevented by electrically pacing the hearts or the administration of atropine, the depressed dP/dt rose to control levels. Reduction in myocardial temperature and heart rate by means of reduction in perfusate temperature of the isolated hearts reduced the myocardial depressant effect of methylmethacrylate.
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PMID:Cardiovascular effects of total hip placement in man. With observations on the effects of methylmethacrylate on the isolated rabbit heart. 1 17

Diazepam and flunitrazepam were compared in equipotent doses as induction agents for premedicated patients having cardiac surgery. Both drugs caused a significant fall in arterial blood pressure, a rise in Paco2 and a fall in Pao2. There was no significant difference between the two drugs in onset time of anaesthesia, cardiovascular or respiratory depression, or quality of induction. There was also no significant difference from induction with thiopentone in these respects. Diazepam, over a 0.2 to 0.6 mg/kg range of doses showed no difference in toxicity, although induction was clinically smoother with the higher dose.
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PMID:Diazepam and flunitrazepam as induction agents for cardiac surgical operations. 2 Jul 27

Halothane, methoxyflurane, and enflurane produce dose-dependent depression in ventricular function in the dog. Myocardial blood flow and oxygen consumption are decreased accordingly without evidence of myocardial tissue hypoxia. Low-dose fluoxene does not depress the heart, while there is less depression with high-dose fluroxene than with the other anesthetics. In spite of this depression, myocardial blood flow was unchanged, and the decreased oxygen consumption during high-dose fluroxene was a result of decreased oxygen extraction by the heart. Sympathetic nervous system stimulation produced by fluroxene anesthesia is probably responsible for these effects, but further work is necessary for confirmation of this hypothesis.
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PMID:Dose-dependent depression of cardiac function and metabolism by inhalation anesthetics in chronically instrumented dogs. 2 4

In addition to those children delivered by cesarean, a noticeable number of premature infants show a neonatal depression without intrauterine or neonatal acidosis. The reasons for this are only partially known. Anesthesia, on the one hand, and the underdeveloped brain, on the other hand, are held responsible. The prognosis of these children is relatively serious. On the one hand, they show a frequent incidence of neurologic disorders, or an increased rate of deformity on the other which although without immediate intrauterine consequences, will render extrauterine life substantially more difficult, if not impossible.
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PMID:[Neonatal depression in the absence of azidose (author's transl)]. 2 8

Under light general anaesthesia the speed of onset of action of fazadinium, pancuronium, tubocurarine and suxamethonium has been assessed by measuring the decrease in the twitch height of the adductor pollicis muscle following administration of the drugs. Suxamethonium produced 95% depression of the twitch height significantly faster than any of the other drugs, while the onset of fazadinium was significantly more rapid than that of the other non-depolarizing neuromuscular blocking drugs.
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PMID:Comparison of speed of onset of fazadinium, pancuronium, tubocurarine and suxamethonium. 2 69

In 32 patients between 53 and 86 years of age, undergoing transurethral prostatectomy, the influence of intraoperative sedation with Diazepam (5-10 mg) and Flunitrazepam (0,4-0,8 mg) on postoperative forced vital capacity, forced exspiratory volume (1 sec.) and peakflow, were measured, compared to placebo. We could not find a depression of these ventilatory parameters, in the three groups except peak-flow after sedation with Flunitrazepam in the evening after operation (p less than or equal to 0,05). We conclude that sedation during regional anesthesia does not impair the most important advantage of local anesthesia, the minor effect on ventilation, compared with general anesthesia.
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PMID:[The influence of sedation with diazepam and flunitrazepam during regional anaesthesia upon postoperative pulmonary performance (author's transl)]. 3 76

The responsiveness of phasically active brainstem respiratory neurons to several amino acids was investigated in cats under Dial anesthesia. Four-barreled microelectrodes were used to extrude iontophoretically the putative neurotransmitters L-glutamate, L-asparatate, glycine, and gamma-aminobutyric acid (GABA), L-glutamate and L-aspartate caused increased activity when applied to either inspiratory or expiratory neurons and appeared to be equal in efficacy. Likewise, GABA and glycine depressed ongoing phasic neural activity of both inspiratory and expiratory units. In this case, however, the dosage of GABA required to produce a given depression was significantly less than the required dosage of glycine. These findings support the hypothesis that L-glutamate and/or L-aspartate may act as excitatory neurotransmitter agents at the synapses of brainstem respiratory neurons and conversely, GABA may act as the natural inhibitory neurotransmitter.
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PMID:Effects of excitatory and inhibitory amino acids on phasic respiratory neurons. 3 45


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