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PubMed1997

The effects of epidural fentanyl on hemodynamic responses during emergence from isoflurane anesthesia and tracheal extubation: a comparison with intravenous fentanyl.

To investigate the effects of epidural fentanyl infusion on hemodynamic responses to recovery of consciousness and tracheal extubation, we studied 50 unpremedicated patients scheduled for abdominal hysterectomy. All patients underwent epidural catheterization and blind infusion of placebo and study drug. Patients were assigned randomly to three groups: Group I received epidural and intravenous (i.v.) bolus injections and infusion of saline at the rate of 0.2 mL x kg(-1) x h(-1); Group II received an i.v. injection of fentanyl 2 microg/kg for 30 s followed by 25 ng x kg(-1) x min(-1), and Group III received epidural injection and infusion using the same administration regimen as Group II. Anesthesia was induced with and maintained by isoflurane alone in an air-oxygen mixture. The study drug was administered at the start of retroperitoneal suturing. Hemodynamic variables, including systolic and diastolic arterial pressures (SAP and DAP, respectively) and heart rate (HR), were recorded every minute between the start of administration of the study and 5 min after tracheal extubation. During emergence from anesthesia and tracheal extubation, the increases in SAP, DAP, and HR in Groups II and III were significantly diminished (P < 0.05) compared with those in Group I. Arterial pressures, but not HR, were attenuated more significantly in Group III than in Group II during and after tracheal extubation, although the plasma fentanyl concentration was significantly lower (P < 0.01) in Group III (0.64 +/- 0.03 ng/ mL, [mean +/- SD]) than in Group II (1.15 +/- 0.09 ng/mL). The incidence of coughing during and after extubation was also lower with Group III. Suppression of respiratory rate prior to tracheal extubation was similar in the two groups receiving fentanyl. These findings suggest that the significant reduction in arterial pressures responses to tracheal extubation due to epidural fentanyl infusion may arise from more suppression of cough reflex than i.v. fentanyl infusion, which could be provided by the spinal action of epidural fentanyl as well as the supraspinal action.

Adjuvants, Anesthesia↗

PubMed2006

A combination of fentanyl-midazolam-propofol provides better intubating conditions than fentanyl-lignocaine-propofol in the absence of neuromuscular blocking agents.

BACKGROUND: The use of propofol and adjuvants such as opioids, benzodiazepines and local anaesthetic agents, may provide adequate conditions for tracheal intubation without the need for neuromuscular blocking agents. In this randomized, double-blind study, intubating conditions after induction of anaesthesia with propofol, midazolam and fentanyl were compared with those after propofol, lignocaine and fentanyl. METHODS: In 80 ASA I/II adult patients undergoing elective gynaecological surgery, intubating conditions were compared after induction of anaesthesia with a fentanyl 2 microg/kg, midazolam 0.03 mg/kg, propofol 2.5 mg/kg combination (group FMP) vs. a fentanyl 2 microg/kg, lignocaine 1.5 mg/kg, propofol 2.5 mg/kg combination (group FLP). Intubating conditions were assessed using a qualitative scoring system. RESULTS: Intubation was successful in all patients in group FMP and in 87.5% of patients in group FLP; (P= 0.021). Overall, intubating conditions were clinically acceptable in 77.5% and 55% of patients in group FMP and group FLP, respectively (P= 0.033). CONCLUSION: We conclude that the fentanyl, midazolam, propofol combination more reliably provides acceptable conditions for intubation than the fentanyl, lignocaine, propofol combination. Intubation was successful in all patients receiving the fentanyl, midazolam, propofol combination.

Adult↗

PubMedDate not supplied

Comparison of plasma fentanyl concentrations by using three transdermal fentanyl patch sizes in dogs.

OBJECTIVE: To compare plasma fentanyl concentrations attained after the application of three transdermal fentanyl patch sizes (50, 75, and 100 micrograms/hour) in dogs. DESIGN: Repeated Latin square controlled study. ANIMALS: Six intact, mixed-breed adult dogs (2 males, 4 females) weighing 19.9 +/- 3.4 kg. METHODS: Each dog was randomly assigned to receive each of three treatments: 50 (P50), 75 (P75), or 100 (P100) micrograms/hour transdermal patches. Patches were left in place for 72 hours. Jugular venous blood was collected at 1, 2, 4, 8, 12, 24, 36, 48, 60, and 72 hours after patch application and for 1, 2, 4, 8, and 12 hours after patch removal. Plasma fentanyl concentrations were measured using a radioimmunoassay technique. After a 96-hour washout period, each dog was moved to another treatment group and received a different patch size. RESULTS: The following results were obtained (mean +/- SD): average plasma fentanyl concentration from 24 to 72 hours, 0.7 +/- 0.2 ng/mL (P50), 1.4 +/- 0.5 ng/mL (P75), 1.2 +/- 0.5 ng/mL (P100); the total area under the concentration versus time curve (0 hours to infinity), 46 +/- 12.2 ng/h/mL (P50), 101.2 +/- 41.4 ng/h/mL (P75), 80.4 +/- 38.3 ng/h/mL (P100); and the apparent elimination half-life, 3.6 +/- 1.2 hours (P50), 3.4 +/- 2.7 hours (P75), and 2.5 +/- 2.0 hours (P100). There was a high degree of variability in plasma fentanyl concentrations achieved. Plasma fentanyl concentrations declined rapidly after patch removal. CONCLUSIONS: The attainment of steady-state plasma concentrations takes up to 24 hours, and there is a great deal of variability in the final concentrations reached in different individuals. In this study, the 100 micrograms/hour patches did not provide statistically increased plasma concentrations when compared with the 50 micrograms/hour patches. CLINICAL RELEVANCE: Because of the interindividual and intraindividual variation in plasma fentanyl concentrations, patches should be applied 24 hours before the anticipated time that analgesia will be required. Adequacy of analgesia and potentially deleterious side effects, such as sedation and respiratory depression, should be monitored while the patches are in place. Skin reactions may occur, and the patches should be removed if such skin irritation is seen. After the patch is removed, it is expected that analgesia will wane rapidly because of the brief elimination half-life.

Administration, Cutaneous↗

PubMed1992

[Clinical manifestations and serum fentanyl concentrations during epidural high dose fentanyl anesthesia].

Twelve elective abdominal surgeries were performed under epidural anesthesia with high dose fentanyl. An epidural catheter was inserted at Th9-Th12 interspace and fentanyl 10 micrograms.kg-1 with [E (+)] or without [E(-)] epinephrine 1:100,000 was given for each group of 6 patients. After the administration of epidural fentanyl, arterial blood was sampled at 5, 10, 15, 30, 60, 120, 180, 240 minutes. The serum concentrations of fentanyl were measured by gas chromatography. The peak concentration of serum fentanyl was observed in the E (-) group, while that was not seen in the E (+) group. The time of reach maximum serum concentration after epidural fentanyl administration in the E (-) group was from 10 to 15 minutes. In two cases of E (-) group, the plasma concentration-time course could be fitted to two-compartment model. The others could be fitted neither to a two-compartment nor to a three-compartment model. In both groups, we could maintain anesthesia with enflurane of less than 0. 4%, and N2O, 66%. It is suggested that analgesic effect of fentanyl on opioid receptor of spinal cord plays a major role in this anesthesia method.

Abdomen↗

PubMed1990

Comparison of continuous epidural infusion of fentanyl and fentanyl-bupivacaine for post cholecystectomy pain control.

Epidural narcotics has been shown to produce profound and long-lasting analgesia. It has been suggested that lipid-soluble narcotics such as fentanyl, because of their short transit time in the CSF, are less likely to be associated with delayed respiratory depression and side effects. We tried to combine low concentrations of fentanyl with bupivacaine to minimize side effects and to see if synergistic effect existed. Forty ASA physical status I or II patients who present for cholecystectomy were included in the trial. Before surgery a thoracic epidural catheter was inserted and pain control began when patients became fully awake and complained of pain in the recovery room after surgery. Patients were randomized in a double-blind fashion to one of four groups. Patients in group I were given epidural infusions of fentanyl 0.001%; patients in group 2 received fentanyl 0.001% mixed with bupivacaine 0.1%; patients in group 3 received fentanyl 0.0005%; patients in group 4 received fentanyl 0.0005% mixed with bupivacaine 0.1%. A continuous epidural infusion of these drugs began at a rate of 10 mL/h after a 5-mL bolus of the solution. Pain relief was assessed with visual analogue pain scale. Respiratory rates, vital signs, and mental status were assessed hourly. Except the group 3, the degree of analgesia achieved was similarly satisfactory in all other groups. There was no respiratory depression developed in either group. Motor block was minimal or absent in all groups. The incidence of nausea and pruritus was significant less in group 3 and group 4. In conclusion, the continuous infusion of dilute bupivacaine with fentanyl provides synergistic analgesia with minimal side effects.

Analgesia, Epidural↗

PubMed1981

[Comparative analgesic kinetics of fentanyl and droperidol-fentanyl association (author's transl)].

UNLABELLED: To specify pharmacological interferences between droperidol and fentanyl an experimental study was carried out on mice. The analgesic kinetic was studied after the administration of the two drugs in a concentration ratio between 25/1 and 150/1. RESULTS: Fentanyl is a potent analgesic with a short time effect. It has very good correlations between dose effect and time effect. Droperidol does not have a analgesic effect. The behaviour of the two drugs depends on the way they are administered, either simultaneously or consecutively: simultaneous administration of the two drugs increases the level and duration of analgesia: nalaxone reverses analgesia, a fentanyl injection given 5 minutes before a droperidol injection produces the same analgesia as fentanyl alone, a droperidol injection given 5 minutes before a fentanyl injection induces a level of analgesia lower than fentanyl alone. Droperidol appears to reverse the fentanyl analgesia.

Analgesics↗

PubMed2000

Assessing the impact of heat on the systemic delivery of fentanyl through the transdermal fentanyl delivery system.

OBJECTIVES: To examine the effects of locally applied heat on the systemic delivery of fentanyl through the Transdermal Fentanyl Delivery System. DESIGN: Open, 2-period crossover randomized study conducted in the anesthesia department of a university teaching hospital. METHOD: Six healthy adult volunteers received a fentanyl 25-microg/h patch with and without local heat for 240 minutes followed by administration without heat for an additional 20 hours. Participants then crossed over. Venous blood was drawn at baseline and hourly for 24 hours. Peak plasma concentration (CMax) of fentanyl was measured and the area under the curve (AUC) of the plasma fentanyl concentration versus time post administration graph was evaluated. RESULTS: Difference in CMax and AUC were not statistically significant over the entire 24-hour study period. However, for the 4-hour period of heat application statistically significant differences were seen in both mean CMax (heat, 0.4 ng/mL versus no heat, 0.1 ng/mL (P =.030)) and mean AUC (heat, 40 ng/mL x min versus no heat, 10 ng/mL x min (P =.010)). CONCLUSION: Local heat can speed the onset of steady state fentanyl concentration in the Fentanyl Transdermal Drug Delivery System thus limiting the delay in onset of analgesia and allowing earlier identification and treatment of side effects.

Clinical Trial↗

PubMed2002

Addition of bupivacaine 1.25 mg to fentanyl confers no advantage over fentanyl alone for intrathecal analgesia in early labour.

PURPOSE: a) To evaluate the effect of adding 1.25 mg of bupivacaine to intrathecal fentanyl on the duration of analgesia in an Asian population and b) to examine if the baricity of the local anesthetic at this dose has any bearing on the duration and quality of block. METHODS: Forty-eight parturients in early labour received combined spinal epidural (CSE) analgesia to evaluate a) the effect of adding 1.25 mg of bupivacaine to intrathecal (IT) fentanyl 25 microg on the duration of analgesia and b) the effect of baricity of intrathecal local anesthetic on the duration and quality of the block. Patients were randomly allocated to receive: IT fentanyl 25 microg plus normal saline (Group f, n=16), IT fentanyl 25 microg plus plain bupivacaine 1.25 mg (Group f+pb, n=16) and IT fentanyl 25 microg plus heavy bupivacaine 1.25 mg (Group f+hb, n=16). The two components of the IT injectate (total of 2.25 mL) were given sequentially. RESULTS: Group f+hb had the lowest sensory dermatomal block (T7 vs T4 (Group f), T5 (Group f+pb), P <0.01). There were no differences in the duration of analgesia and incidence of side effects among the groups. CONCLUSION: We found no advantage of adding 1.25 mg bupivacaine to fentanyl 25 microg. At this dose, the baricity of bupivacaine has no effect on the duration of analgesia.

Adult↗

PubMed1990

The efficacy of transdermal fentanyl in the treatment of postoperative pain: a double-blind comparison of fentanyl and placebo systems.

Forty consenting patients scheduled for abdominal surgery were entered into a double-blind comparison of the efficacy of transdermal fentanyl (TTS-fentanyl) and placebo (TTS-placebo) in the treatment of postoperative pain. All patients were allowed supplementary pethidine (25-50 mg) if pain relief was inadequate provided that their respiratory rate was greater than 10 breaths/min and there was no pronounced CNS depression. Visual analogue pain scores (VAPS), sedation rating scores (SRS), blood samples for the determination of fentanyl concentration, blood pressure, pulse and respiratory rate were determined hourly for 48 h from the time of TTS system application. The first lot of TTS systems were removed after 24 h and a second lot were applied which remained in situ for a further 24 h. There was no significant difference between the patients in the TTS-fentanyl and TTS-placebo groups in the VAPS throughout the 0-12, 12-24, 24-36 and 36-48 h periods suggesting that the quality of pain relief was similar between the 2 groups. However, significantly less supplementary pethidine was administered to the TTS-fentanyl group in the 12-24, 24-36 and 36-48 h periods. In contrast, the amount of supplementary pethidine administered in the 0-12 h period was similar in both groups which was consistent with the long delay time (mean +/- S.D. value of 16.6 +/- 10 h) before clinically effective concentrations of fentanyl were obtained from the systems. The profile of side effects was similar in the 2 groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Cutaneous↗

PubMed2006

Relative bioavailability of the fentanyl effervescent buccal tablet (FEBT) 1,080 pg versus oral transmucosal fentanyl citrate 1,600 pg and dose proportionality of FEBT 270 to 1,300 microg: a single-dose, randomized, open-label, three-period study in healthy adult volunteers.

BACKGROUND: The fentanyl effervescent buccal tablet (FEBT) was designed to enhance the rate and extent of absorption of fentanyl through the buccal mucosa. FEBT is being investigated for the management of breakthrough pain. OBJECTIVES: The primary objective of this study was to compare the relative bioavailability of FEBT 1,080 microg with that of oral transmucosal fentanyl citrate (OTFC) 1,600 microg, and the secondary objective was to assess the dose proportionality of FEBT 270 to 1,300 microg in healthy adult volunteers. METHODS: This single-dose, randomized, open-label, 3-period study was conducted by MDS Pharma Services, Lincoln, Nebraska. Non-opioid-tolerant healthy adult volunteers were included. In periods 1 and 2 (relative-bioavailability analysis), subjects were randomly assigned to 1 of 2 administration sequences: single-dose FEBT 1,080 microg followed by single-dose OTFC 1,600 microg, or vice versa; in period 3 (dose-proportionality analysis), they were randomly assigned to receive a single dose of FEBT 270, 810, or 1,300 microg. Subjects were instructed to place FEBT between the gum and cheek above an upper molar tooth and allow it to disintegrate for 10 minutes. Subjects were instructed to place the OTFC lozenge between the cheek and lower gum and move the unit from side to side using the handle and allow the unit to dissolve for 15 minutes. All subjects received naltrexone 50 mg PO at 15 and 3 hours before and 12 hours after fentanyl administration, except those receiving FEBT 270 microg, who were not given naltrexone at 12 hours. For the measurement of serum concentrations of fentanyl, venous blood samples were collected before and up to 36 hours after study drug administration. For tolerability analysis, continuous pulse oximetry, 12-lead electrocardiography, clinical laboratory analysis, and physical examination, including vital-sign measurements, were performed; the oral mucosa was inspected; and spontaneous reporting was employed. RESULTS: A total of 42 subjects were enrolled (25 women, 17 men; mean [SD] age, 27 [11] years; mean [SD] weight, 68.4 [8.7] kg); 39 completed the study. Total systemic exposure (as measured using AUC(0-infinity))) was statistically similar between FEBT 1,080 microg and OTFC 1,600 microg (mean [SD], 18.0 [5.4] vs 18.0 [7.1] ng x h/mL). However, the mean (SD) C(max) with FEBT 1,080 microg was 2.7 (0.9) ng/mL compared with 2.2 (0.7) ng/mL with OTFC 1,600 microg (P = NS), and the T(max) of 1.0 hour with FEBT was significantly less compared with OTFC (2.0 hours; P < 0.001). Similarly, mean (SD) early systemic exposure (AUC(0-Tmax'); ie, AUC from time 0 to 1 hour the median T(max) of the reference dose of FEBT [810 microg]) was significantly greater with FEBT compared with OTFC (1.5 [0.5] vs 0.8 [0.4] ng x h/mL; P < 0.001). Exploratory analyses suggested dose proportionality as assessed using AUC(0-infinity) and AUC(0-Tmax') over the range of FEBT 270 to 1,300 microg. Increases in C(max) were less than dose proportional at FEBT doses >810 microg. Definitive attribution of adverse events (AEs) to FEBT or OTFC was generally not possible because these medications were coadministered with naltrexone. With naltrexone alone, there were reports of headache (3 [7%] subjects), nausea (1 [2%]), upset stomach (1 [2%]), and low systolic blood pressure (1 [2%]) after naltrexone administration, but before FEBT or OTFC administration. The AEs were typical of opioids (ie, headache, nausea, lightheadedness), and most (89.6%) were mild. One case each of mild oral irritation and redness were reported after the administration of FEBT Both occurrences resolved within 4.5 hours after study drug administration. No irritation or redness was reported after the administration of OTFC. CONCLUSIONS: In this pharmacokinetic study in healthy volunteers, total systemic exposure increased in a dose-proportional manner up to FEBT 1,300 microg, whereas doses above 810 microg showed a less-than-dose-proportional increase in C(max). The results suggest that fentanyl enters the systemic circulation to a significantly greater extent (C(max) and AUC(0-Tmax')) and significantly more rapidly (T(max)) with FEBT compared with OTFC.

Administration, Buccal↗

PubMed2005

Comparison of maternal and neonatal outcomes with epidural bupivacaine plus fentanyl and ropivacaine plus fentanyl for labor analgesia.

BACKGROUND: Several studies have been performed to find a safe method of labor analgesia with minimal side effects and toxicity in mother and fetus. We aimed to compare the efficacy and side effects of epidural bupivacaine plus fentanyl and ropivacaine plus fentanyl at low concentrations. METHOD: Forty ASA I-II parturients' were included in this prospective, double-blind, trial and randomized to receive either bupivacaine or ropivacaine for labor analgesia. Analgesia was initiated with 8 mL of 0.125% solution plus fentanyl 50 microg and maintained with a continuous infusion of 0.0625% solution with fentanyl 2 microg/mL. RESULTS: There were no differences in pain scores, total dose of local anesthetics used, sensory or motor blockade, labor duration, mode of delivery, side effects, patient satisfaction, or neonatal outcome between the two local anesthetics at these dosages, but at the end of the second stage and delivery, adequate analgesia quality could not be ensured. CONCLUSION: We found no major advantage of continuous epidural infusion of ropivacaine 0.0625% plus fentanyl 2 microg/mL over bupivacaine 0.0625% plus fentanyl 2 microg/mL for labor analgesia. We believe that different methods or dosages may be tried in order to improve comfort at the second stage of labor and the delivery.

Adult↗

PubMed1975

Hemodynamic and ventilatory responses to fentanyl, fentanyl-droperidol, and nitrous oxide in patients with acquired valvular heart disease.

Fentanyl (10 mug/kh) or fentanyl (10 mug/kg) plus droperidol (100 mug/kg) administered intravenously during 20 minutes to adult patients with acquired valvular heart disease produced minimal circulatory changes. The trend during drug infusion was for mean arterial pressure and systemic vascular resistance to decrease, and for cardiac index and stroke volume index to increase without change in heart rate. Central venous pressure increased during drug infusion (P less than 0.05) but decreased to awake levels following controlled ventilation and skeletal-muscle paralysis, probably reflecting thoracoabdominal-muscle rigidity rather than a circulatory response. Hypoventilation during drug infusion necessitated assisted or controlled ventilation, with or without skeletal muscle paralysis, in 14 of 16 patients. Addition of 60 per cent nitrous oxide following fentanyl or fentanyl-droperidol infusion significantly decreased mean arterial pressure, heart rate, and cardiac index. All circulatory changes were similar in direction and extent to those previously found during morphine-nitrous oxide anesthesia. (Key words: Anesthetics, intravenous, fentanyl; Anesthetics, gases, nitrous oxide; Heart, effect of fentanyl, dorperidol, and nitrous oxide.).

Adult↗

PubMed1982

Continuous thoracic epidural fentanyl. A comparison of epidural fentanyl with intramuscular papaveretum for postoperative pain.

A prospective open trial was conducted to compare the analgesic and side-effects of continuously infused fentanyl into the thoracic epidural space with those of intramuscular papaveretum given 4 hourly as required. It was demonstrated that during the first 24 hours after upper abdominal surgery thoracic epidural fentanyl produced better analgesia with less sedation than intramuscular papaveretum. However, the epidural group suffered more nausea. Likewise, postoperative respiratory function tests were statistically significantly better in those patients who received epidural fentanyl. Despite a significantly greater volume of nasogastric aspirate during the period of study, the epidural fentanyl group also had a significantly greater urine output than did the patients receiving papaveretum. Hypotension and respiratory depression were not problems, but pruritus occurred in two patients given fentanyl. It is concluded that epidural fentanyl delivered by continuous infusion offers significant advantages over a conventional intramuscular narcotic regime.

Adult↗

PubMed2004

Plasma fentanyl concentrations and analgesic effects during full or partial exposure to transdermal fentanyl patches in cats.

OBJECTIVE: To compare plasma fentanyl concentrations and analgesic efficacy during full or partial exposure to 25-microg/h transdermal fentanyl patches (TFPs) in cats undergoing ovariohysterectomy. DESIGN: Randomized controlled clinical trial. ANIMALS: 16 client-owned cats. PROCEDURE: Cats were randomly assigned to receive full or partial exposure to a TFP; patches were applied approximately 24 hours prior to ovariohysterectomy. Rectal temperature, heart rate, respiratory rate, blood glucose concentration, and blood pressure were measured and pain severity was assessed periodically for 72 hours after patch application. Venous blood samples were collected for determination of plasma fentanyl concentration 0, 6, 12, 18, 24, 36, 48, 60, and 72 hours after patch application. RESULTS: Mean +/- SD steady state plasma fentanyl concentration in cats in the full TFP exposure group (1.78 +/- 0.92 ng/mL) was significantly greater than concentration in cats in the partial exposure group (1.14 +/- 0.86 ng/mL). Steady state plasma fentanyl concentrations were evident between 18 and 72 hours after patch application. Subjective scores used to evaluate analgesic efficacy were not significantly different between treatment groups. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that delivery of fentanyl from TFPs can be reduced by decreasing the amount of exposed surface area. In cats weighing < 4 kg (9 lb), exposure to half a 25-microg/h TFP appears to provide adequate analgesia following ovariohysterectomy.

Administration, Cutaneous↗

PubMed2003

[Intravenous anesthesia using continuous administration of propofol and fentanyl: fentanyl administration procedure and quality of awareness].

BACKGROUND: We studied total intravenous anesthesia using continuous administration of propofol and fentanyl and examined especially the method of fetanyl administration. METHODS: Anesthesia was induced with fentanyl 2 micrograms.kg-1 and propofol 2 mg.kg-1. Fentanyl 1 microgram.kg-1 was then administered before the start of the operation and infused continuously at a rate of 0.02 microgram.kg-1.min-1 during operation. Propofol was also infused continuously at 4-10 mg.kg-1.min-1. RESULTS: These methods allowed a significant reduction in the necessary dose of fentanyl and propofol compared with ordinary methods, and a stable general condition was maintained during the operation. Additionally, high quality of awareness was obtained after the recovery. CONCLUSIONS: This continuous administration procedure of fentanyl reduced the total doses of both propofol and fentanyl, allowing high quality of awareness after the recovery.

Adult↗

PubMed1988

Cardiac electrophysiologic effects of fentanyl and combinations of fentanyl and neuromuscular relaxants in pentobarbital-anesthetized dogs.

The effects of fentanyl, both alone and in combination with pancuronium bromide or succinylcholine, on atrioventricular (AV) node and ventricular conduction times and refractory periods were studied. Twenty-four pentobarbital-anesthetized dogs were instrumented both with an intraaortic catheter to measure cardiac conduction times and, through a thoracotomy, with atrial and ventricular epicardial pacing electrodes to provide premature stimulation that would allow measurement of atrial and ventricular refractoriness. Fentanyl prolonged the RR interval in both low- (100 micrograms/kg) and high-dose (400 micrograms/kg) groups by 26 and 45%, respectively, and prolonged AV node conduction time by 28 and 25%, respectively. During atrial pacing at a rate sufficient to capture the atria, AV node conduction time lengthened in the low- and high-dose groups by 27 and 25%, respectively. Fentanyl also significantly lengthened AV node effective and functional refractory periods and ventricular effective refractory periods in both groups. Pancuronium (0.1 mg/kg) administered after fentanyl shortened RR intervals in the low- and high-dose groups by 14 and 22%, respectively, and shortened AV conduction times by 18 and 20%, respectively, but did not restore all values to baseline. Pancuronium significantly shortened AV node refractory periods in the low-dose but not the high-dose group. When administered after fentanyl, succinylcholine (2 mg/kg) significantly shortened the RR interval in the low- and high-dose groups by 14 and 12%, respectively. Succinylcholine shortened AV node conduction slightly but without significance and had no effect on cardiac refractoriness. His-Purkinje conduction remained unaffected by any drug intervention. These data demonstrate that fentanyl depresses cardiac conduction; subsequent administration of pancuronium and succinylcholine partially reverses this effect.

Animals↗

PubMedDate not supplied

[Comparison between fentanyl and a fentanyl-bupivacaine combination using epidural PCA for postoperative analgesia after thoracotomy].

HYPOTHESIS: The association of opioids and local anesthetics for spinal analgesia appears to have a synergistic++ effect. OBJECTIVE: To compare the efficacy of fentanyl in comparison with combined fentanyl and bupivacaine at low concentrations in a thoracic epidural system of patient-controlled analgesia (PCA) following thoracotomy. PATIENTS AND METHODS: Twenty male patients scheduled for thoracotomy by postero-lateral (T5-T6) incision received analgesia after surgery through a thoracic (T4-T8) epidural catheter connected to a PCA pump (continuous infusion and boluses). They were randomly assigned to 2 groups as follows: group A (n = 10) received a baseline infusion of fentanyl 1 microgram/kg/h and bupivacaine 0.125% with boluses of 12.5 micrograms fentanyl and bupivacaine at 0.125%. The variables studied were: score on a visual analog scale (VAS) before treatment and at 12 and 24 h; the number of boluses administered through the PCA pump, forced vital capacity (FVC) and peak expiratory flow (PEF) before treatment and at 12 h. RESULTS: Analgesia was satisfactory in both groups, with no significant differences in VAS and number of boluses administered. Nor were there significant differences in lung function tests. One instance of respiratory depression was recorded in group A. CONCLUSIONS: The analgesic effect obtained with epidural fentanyl or fentanyl/bupivacaine is similar and adequate, and the association of fentanyl and bupivacaine can be considered safe.

Aged↗

PubMed2001

Hemodynamic stability during induction of anesthesia and tracheal intubation with propofol plus fentanyl, ketamine, and fentanyl-ketamine.

PURPOSE: This study was conducted to investigate hemodynamic and cardiac stability during anesthesia induction and intubation, using propofol plus fentanyl, propofol plus ketamine, and propofol plus fentanyl and ketamine. METHODS: Forty-five adult patients were randomly allocated to one of three groups according to the agents used for induction: propofol (2 mg/kg) plus fentanyl (3 microg/kg) (PF), propofol (2 mg/kg) plus ketamine (0.1 mg/kg) (PK), and propofol (2 mg/kg) plus fentanyl (3 microg/kg) plus ketamine (0.1 mg/kg) (PFK). Hemodynamic responses were assessed by measuring changes in blood pressure (BP), heart rate (HR), and cardiac output (CO; using dye dilution combined with pulse dye densitometry [PDD]). RESULTS: BP and HR changes during the induction of anesthesia tended to be greater in the PK group than in the PF and PFK groups. After the injection of propofol, the cardiac index (CI) fell significantly below baseline values in the PF and PFK groups, but remained unchanged in the PK group. After tracheal intubation, BP and HR increased significantly only in the PF and PK groups, and reached a level significantly above baseline values only in the PK group. The CO responses to tracheal intubation were: PK group > PF group > PFK group. CONCLUSION: A combination of propofol plus fentanyl plus ketamine would provide greater reduction of fluctuations in hemodynamic variables associated with induction of anesthesia and tracheal intubation than combinations of propofol plus fentanyl or propofol plus ketamine.

Clinical Trial↗