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)

Fentanyl, unlike morphine, is highly lipophilic and rapidly diffuses out of the epidural space. Respiratory depression is, therefore, unlikely when fentanyl is given epidurally. However, much of fentanyl's analgesic effect is mediated by systemic rather than spinal receptor binding. To test this hypothesis, we performed a prospective, double-blind, cross-over study comparing epidural and intravenous (IV) administration of fentanyl in 16 patients for the first 12 h after lower abdominal or lower extremity surgery. To allow direct comparison of these two routes of administration, patient-controlled analgesia was used so patients could self-titrate their analgesia. Patients were randomized to receive fentanyl initially by an epidural (group A, n = 8) or IV (group B, n = 8) catheter for 6 h, after which they were crossed-over to the alternate route by means of a hidden three-way stopcock. The degree of analgesia was subjectively evaluated by a visual analogue scale, and by an observer rating patient's comfort and sedation. Cumulative dosage of fentanyl was recorded, and plasma fentanyl concentrations were measured. The onset of analgesia and increase in plasma fentanyl concentrations were more rapid with intravenous fentanyl. However, after 60 min, analgesia (visual analogue scale 2-4 cm) or plasma fentanyl concentrations (0.3-0.7 ng/mL) did not differ between the two routes of administration. There were also no significant differences in the cumulative dosage of fentanyl within each group (epidural vs IV) or between the groups. Thus, the analgesic effects of epidural fentanyl appear largely mediated by systemic absorption. Intravenous fentanyl achieves a similar degree of analgesia and a more rapid onset of effect without the need for epidural catheterization.
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PMID:Use of patient-controlled analgesia to compare the efficacy of epidural to intravenous fentanyl administration. 848 28

The intraperitoneal injection of anaesthetic agents is a simple and convenient method of anaesthetizing rats. However, all of the anaesthetic combinations in current use which are administered by intraperitoneal injection produce prolonged sedation, and full recovery of consciousness may take several hours. Fentanyl, a mu agonist opioid, and medetomidine, an alpha 2-adrenoceptor agonist were mixed and administered as a single intraperitoneal injection. Combinations of 300 micrograms/300 micrograms/kg and 300 micrograms/200 micrograms/kg of fentanyl/medetomidine were shown to produce surgical anaesthesia in the rat. This anaesthetic regimen produced significant respiratory depression (P less than 0.01) and animals did not regain their righting reflex until 193 +/- 21 min (mean +/- 1 SD) after injection. Administration by intraperitoneal injection of atipamezole, a specific alpha 2-adrenoceptor antagonist (1 mg/kg) mixed with a mu antagonist/k agonist opioid (nalbuphine, 2 mg/kg or butorphanol 0.4 mg/kg), resulted in a rapid (less than 8 min) reversal of anaesthesia and the associated respiratory depression, and apparent full recovery of consciousness.
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PMID:Fentanyl and medetomidine anaesthesia in the rat and its reversal using atipamazole and either nalbuphine or butorphanol. 154 41

The effects of propofol, etomidate, midazolam, and fentanyl on motor evoked responses to transcranial stimulation (tc-MERs) were studied in five healthy human volunteers. Each subject, in four separate sessions, received intravenous bolus doses of propofol 2 mg.kg-1, etomidate 0.3 mg.kg-1, midazolam 0.05 mg.kg-1, and fentanyl 3 micrograms.kg-1. Electrical tc-MERs (tce-MERs) were elicited with anodal stimuli of 500-700 V. Magnetic tc-MERs (tcmag-MERs) were elicited using a Cadwell MES-10 magnetic stimulator at maximum output. Compound muscle action potentials were recorded from the tibialis anterior muscle. Duplicate tce-MERs and tcmag-MERs were recorded before and up to 30 min after drug injection. Reproducible baseline tce-MERs (amplitude 4.7 +/- 0.43 (SEM) mV, latency 29.4 +/- 0.35 ms) and tcmag-MERs (amplitude 3.7 +/- 0.43 mV, latency 31.1 +/- 0.39 ms) were obtained in all subjects. Pronounced depression of tce-MER amplitude to 2% of baseline values (P less than 0.01) was observed 2 min after injection of propofol. Thirty minutes after injection of propofol, amplitude depression to 44% of baseline (P less than 0.05) was still present, despite an apparent lack of sedation. Midazolam caused significant (P less than 0.01) amplitude depression, e.g., tcmag-MER to 16% of baseline values 5 min after injection. Significant depression persisted throughout the 30-min study period. Fentanyl did not cause any statistically significant amplitude changes in this small population. Etomidate caused significant but transient depression of tc-MER amplitude. However, there was considerable intersubject variability. Latency did not change significantly after any drug.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of propofol, etomidate, midazolam, and fentanyl on motor evoked responses to transcranial electrical or magnetic stimulation in humans. 155 Feb 74

Epidural fentanyl is often added to epidural local anaesthetic agents to improve the quality of anaesthesia obtained during Caesarean section. Fentanyl may be given either before or after delivery of the infant. When given before delivery, fentanyl has not been reported to cause neonatal depression, although this remains a concern. A prospective, randomized, double-blind study was undertaken to determine if fentanyl was more effective if given before or after delivery of the baby in 64 women undergoing Caesarean section under lidocaine epidural anaesthesia. Maternal outcome was determined by time to achieve T4 neural blockade, the dose of lidocaine necessary to achieve this block and intraoperative scores for pain, nausea, vomiting, shivering, and sedation. Neonates were assessed by umbilical arterial blood pH and Apgar scores. No differences were detected in either group with respect to maternal or neonatal outcome. We recommend using only epidural local anaesthetic agents before delivery, and giving epidural fentanyl following delivery of the infant.
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PMID:Epidural fentanyl and caesarean section: when should fentanyl be given? 840 64

Surgical stress and general anesthesia can suppress immune function and thus may increase postsurgical infections and tumor metastasis. We previously reported that two narcotics commonly used in high-dose opiate anesthesia (fentanyl and sufentanil) suppress natural killer (NK) cell activity in rats. Such doses of narcotics also cause respiratory depression accompanied by hypoxia, hypercarbia, and acidosis, which might account for the observed narcotic-induced NK suppression. In the present study, we compared the effects of fentanyl on NK activity in ventilated and non-ventilated rats. Fentanyl significantly suppressed NK cell activity to the same magnitude in the two groups, although the groups significantly differed in CO2 and O2 levels. The fact that high-dose fentanyl-induced NK suppression can be demonstrated in ventilated rats accentuates the relevance of these findings to clinical studies showing NK suppression in the immediate postoperative period. Such immunosuppression could be a risk factor for patients undergoing surgery, especially in cancer-related operations.
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PMID:Narcotic-induced suppression of natural killer cell activity in ventilated and nonventilated rats. 164 47

Fentanyl/diazepam anesthesia is an appropriate combination for surgical operations on the guinea pig, since it ensures definitive anesthesia and analgesia without respiratory depression. Comparative investigations with pentobarbital and urethane were carried out to check their applicability for electrocochleographic recordings. We found that fentanyl/diazepam combination anesthesia is more suitable for electrocochleographic investigations than pentobarbital. We were thereby able to prove that pentobarbital has an attenuating effect on electrocochleographic recordings in contrast to the findings reported in the available literature. For this reason, and because the lowest rates of animal morbidity occurred with fentanyl/diazepam, this combination anesthesia should be used preferentially for electrophysiological experiments in guinea pigs.
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PMID:The value of fentanyl/diazepam anesthesia for experimental operations and recordings of compound action potentials in the guinea pig cochlea. 174 48

Transdermal fentanyl 75 micrograms/h (Fentanyl-TTS) was compared with placebo in a randomized double-blind study in the early postoperative period, using 50 patients recovering from major urological operations. Analgesic efficacy was individually titrated with intravenous fentanyl by means of a PCA pump (demand dose 34 micrograms, lockout time 5 min). The test systems were applied 8 h before anaesthesia and were left in situ for 24 h. During the PCA period (18.2 h) patients with Fentanyl-TTS required significantly less additional fentanyl (0.48 vs 0.93 micrograms.kg-1.h-1) and reported less pain than patients in the placebo-group. Patient acceptance was high in both groups. Side-effects were of only minor intensity and did not differ between the two groups. In particular, there was no case of clinically relevant respiratory depression.
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PMID:Transdermal fentanyl for the treatment of pain after major urological operations. A randomized double-blind comparison with placebo using intravenous patient-controlled analgesia. 178 72

The purpose of this retrospective study was to evaluate the combined use of intravenous analgesia, with a potent opiate alone, supplemented by local anaesthesia as an alternative to general anaesthesia for medically compromised patients. Sixty-two in-patients, aged between 32 and 80 years, with an ASA physical status of III and IV, were involved in this study. The local anesthetic used was 4% articain with epinephrine (1:200,000) and narcotic analgesics were Fentanyl or Alfentanil. Surgical procedures included multiple dental extractions, cystectomy and the removal of impacted teeth. All patients completed the surgery without deeper anaesthesia and mostly enjoyed a comfortable intraoperative period. Only one respiratory depression was observed, but quickly reversed. Other adverse effects were few and without consequences, hemodynamic changes remained in tolerable limits. In conclusion this anaesthetic technique can be a suitable alternative to general anaesthesia in oral surgery for high-risk patients.
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PMID:Local anaesthesia with intravenous analgesia as an alternative to general anaesthesia for medically compromised patients undergoing oral surgery. A retrospective study of sixty-two cases. 183 35

Use of the benzodiazepine antagonist flumazenil may inhibit the effects of benzodiazepines in a competitive manner. The only known partially agonistic effect of flumazenil is a weak anticonvulsive action at high doses. However, reports have claimed that flumazenil reduces the MAC of isoflurane in animal studies. Other reports have found that antagonizing midazolam-induced sedation or anesthesia by flumazenil led to an increase in respiratory depression. The aim of this study was to examine whether flumazenil i.v. increases fentanyl-induced respiratory depression. METHODS. In two separate sessions, ten healthy young volunteers were given either 0.0027 mg/kg fentanyl alone or 0.0027 mg/kg and 1 mg flumazenil i.v. over 4 min each time. The CO2 rebreathing method was used to determine the ventilatory response. RESULTS. Fentanyl alone brought about a significant reduction in CO2 response, characterized by a shift to the right and a decrease in the slope of the rebreathing curve (from 1.95 +/- 0.76 l.min-1.mmHg-1 to 0.86 +/- 0.53 l.min-1.mmHg-1). The infusion of additional flumazenil caused similarly significant respiratory depression (from 2.21 +/- 1.0 l.min-1.mmHg-1 to 0.77 +/- 0.38 l.min-1.mmHg-1). In both groups changes persisted for at least 120 min. No statistically significant differences between the two groups could be detected. CONCLUSION. Flumazenil does not enhance fentanyl-induced respiratory depression. Flumazenil's weak, partially agonistic action is therefore of no clinical importance.
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PMID:[The effect of flumazenil on alfentanyl-induced respiratory depression]. 186 67

Propofol (Diprivan), a modern intravenous hypnotic, produces a reduction in both cardiac index (CI) and mean arterial pressure (MAP). Ketamine (Ketanest), a potent analgesic, in contrast, causes an increase in MAP and CI. The aim of the present study was to investigate whether the combination of propofol and ketamine can give better hemodynamic stability during the induction and maintenance of general anesthesia than propofol used with fentanyl, whose cardiodepressant actions may cumulate. METHODS. For induction of general anesthesia 10 patients (ASA I and II) each received 3-5 boluses of propofol (0.5 mg.kg-1 during 35 s until predetermined level of anesthesia was reached (stage D2/E0 according to [20]) followed by a continuous propofol infusion (0.120 mg.kg-1.min). Fentanyl 0.1 mg was administered to each patient in group A for induction of anesthesia and again if evident pain was present. In group B ketamine was given following a pharmacokinetic model based on computer-simulated calculation. After an initial bolus of 38 mg injected within 2 min further doses of 42 mg, 35 mg, 32 mg and 28 mg ketamine were administered over 30 min at a time. Signs of evident pain were treated by means of supplementary doses of 0.5 mg.kg-1. RESULTS. In both groups a moderate drop of MAP was observed after the induction of general anesthesia. Two patients in each group showed a distinct decrease in MAP (-32%). The heart rate dropped slightly (-9%) in group A, but did not change in group B. Following intubation the MAP rose by less in group A (+8%) than in group B (+21%). After the beginning of the operation the group treated with propofol/fentanyl showed major hemodynamic changes; in particular, bradycardia with less than 40 bpm was observed in more patients than in the propofol/ketamine group. Postoperatively, fewer patients in group B required rescue doses of analgesics (1 of 10) than these in group A (7 of 10), though vigilance was better in group B. DISCUSSION. The dose of ketamine administered during the induction of general anesthesia may have been not high enough to neutralize the cardiodepressant effect of propofol. But during the maintenance of anesthesia there was in fact better hemodynamic stability in group B than in group A as a result of the neutralization of opposing actions. Fentanyl even intensified the fall in MAP after propofol. Patients in group B showed better vigilance as well as better pain relief postoperatively. The population of the fentanyl group was obviously more deeply sedated and analgesia was still inadequate. In our study general intravenous anesthesia with propofol and ketamine offered the advantages of better analgesia, a higher state of vigilance and the absence of respiratory depression during the postoperative phase compared with the combination of propofol and fentanyl.
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PMID:[The effect of propofol-ketamine anesthesia on hemodynamics and analgesia in comparison with propofol-fentanyl]. 207 45


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