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Mohamed Naguib - One of the best experts on this subject based on the ideXlab platform.

  • comparison of suxamethonium and different combinations of rocuronium and Mivacurium for rapid tracheal intubation in children
    BJA: British Journal of Anaesthesia, 1997
    Co-Authors: Mohamed Naguib, Abdulhamid H Samarkandi, A Ammar, A Turkistani
    Abstract:

    The use of suxamethonium in children is associated with undesirable side effects. The synergistic effect of a rocuronium-Mivacurium combination can be considered as an acceptable alternative to suxamethonium in clinical practice. The calculated ED50 of the rocuronium-Mivacurium mixture was only 62% of the predicted value assuming a purely additive interaction. The use of this combination has not been evaluated in children. In this two-part study, we assessed the intubating conditions and pharmacodynamics of suxamethonium, rocuronium, Mivacurium or a rocuronium-Mivacurium combinations in children. We studied 120 ASA I children of both sexes, aged 3-10 yr. Children were premedicated with trimeprazine 2 mg kg-1 orally, and received fentanyl 2 micrograms kg-1 and propofol 2 mg kg-1 for induction of anaesthesia. They were allocated randomly to receive one of the following drugs or drug combinations: suxamethonium 1.0 mg kg-1, Mivacurium 0.2 mg kg-1, rocuronium 0.6 or 0.9 mg kg-1, Mivacurium 0.1 mg kg-1 with rocuronium 0.3 mg kg-1 or Mivacurium 0.15 mg kg-1 with rocuronium 0.45 mg kg-1. In part 1, 60 s after administration of the neuromuscular blocking drug or drug combination, tracheal intubation was performed in 60 children by mimicking rapid sequence induction, and intubating conditions were evaluated by a blinded investigator according to a standard score. In part 2, neuromuscular monitoring was established before administration of neuromuscular blocking agent(s) and the time from injection of drug or drug combination until complete ablation of T1 (onset) and recovery of T1 to 25% (duration) were recorded in another 60 children. The frequency of distribution of excellent or good intubating conditions in the higher dose of rocuronium and the combination groups were similar to those in the suxamethonium group, but significantly different (P < 0.05) from those in the Mivacurium group. Mean onset time was faster in the suxamethonium (55.1 (SD 11.4) s), rocuronium 0.9 mg kg-1 (70.5 (37.7) s), Mivacurium 0.1 mg kg-1 with rocuronium 0.3 mg kg-1 (67 (35.9) s) and Mivacurium 0.15 mg kg-1 with rocuronium 0.45 mg kg-1 (55 (26.7) s) groups compared with the Mivacurium 0.2 mg kg-1 (116 (26.8) s) and rocuronium 0.6 mg kg-1 (97.9 (29) s) groups. This study demonstrated that the combination of rocuronium 0.45 mg kg-1 and Mivacurium 0.15 mg kg-1 could possibly be considered as an acceptable alternative to suxamethonium when rapid sequence induction of anaesthesia is indicated in children because it provides uniform excellent intubating conditions and complete neuromuscular block in < 60 s.

  • Dose-response studies of the interaction between Mivacurium and suxamethonium
    British journal of anaesthesia, 1995
    Co-Authors: Mohamed Naguib, Mohamed Abdulatif, M. Selim, A. Al-ghamdi
    Abstract:

    We have determined the effect of pretreatment with Mivacurium on the potency of suxamethonium and the effect of prior administration of suxamethonium on the potency of Mivacurium. We studied 100 ASA I or II patients during thiopentone-fentanyl-nitrous oxide-isoflurane anaesthesia. Neuro-muscular block was recorded as the evoked thenar mechanomyographic response to train-of-four stimulation of the ulnar nerve (2 Hz at 12-s intervals). Single dose-response curves were determined by probit analysis. Pretreatment with Mivacurium had a marked antagonistic effect on the development of subsequent depolarizing block produced by suxamethonium. The dose-response curves for suxamethonium alone and after pretreatment with Mivacurium did not deviate from parallelism, but those constructed after Mivacurium were shifted significantly to the right (P

  • Different priming techniques, including Mivacurium, accelerate the onset of rocuronium
    Canadian Journal of Anaesthesia, 1994
    Co-Authors: Mohamed Naguib
    Abstract:

    Cette étude compare l’influence de différentes séquences d’amorçage avec des doses d’égale puissance de rocuronium et de Mivacurium sur le début du bloc neuromusculaire complet et les conditions d’intubation avec celles de la succinykholine. Pendant une anesthésie au thiopentone-fentanyl-protoxyde d’azote, 70 patients sont assignés au hasard entre sept groupes. Le groupe I reçoit un seul bolus de Mivacurium 0,15 mg · kg^−1. Le groupe II reçoit une dose d’amorce de Mivacurium 0,015 mg · kg^−1 suivie trois minutes plus tard de Mivacurium 0,135 mg · kg^−1. Le groupe III reçoit un seul bolus de rocuronium 0,6 mg · kg^−1. Le groupe IV reçoit une dose initiale de 0,06 mg · kg^−1 de rocuronium suivie de rocuronium 0,54 mg · kg^−1. Le groupe V reçoit une dose initiale de Mivacurium 0,015 mg · kg^−1 suivie de rocuronium 0,54 mg · kg^−1. Le groupe VI reçoit une dose initiale de rocuronium 0,06 mg · kg^−1 suivie par Mivacurium 0,135 mg · kg^−1. Le groupe VII reçoit succinykholine 1,0 mg · kg^−1. Les groupes I, III et VII reçoivent un placébo en injection avant le myorelaxant. Un supplément de thiopentone 2 mg · kg^−1 iv est administré 30 sec avant l’intubation. Le début d’action (moyenne (intervalle de confiance 95%)) après l’amorçage du bloc au rocuronium (73 (57–90) sec) ou au Mivacurium (58 (47–69) sec) est identique à celui qui suit la succinykholine (54 (40–68) sec) et est plus court (P < 0,01) que celui qui est observé dans les autres groupes. Les conditions d’intubation ne diffèrent pas entre les groupes. Le bloc neuromusculaire k plus court est obtenu avec la succinykholine. En conclusion, l’amorçage du bloc neuromusculaire avec soit k Mivacurium soit le rocuronium produit un bloc comparabk à celui de la succinykholine tant pour le début d’action que pour ks conditions d’intubation. Different priming sequences of equipotent doses of rocuronium and Mivacurium on the onset of maximum neuromuscular block and intubating conditions were compared with those obtained after succinylcholine. During thiopentone-fentanylnitrous oxide anaesthesia, 70 patients were randomly assigned into seven groups. Group I received Mivacurium 0.15 mg · kg^−1 as a single bolus dose. Group II received a priming dose of Mivacurium 0.015 mg · kg^−1 followed three minutes later by Mivacurium 0.135 mg · kg^−1. Group III received rocuronium 0.6 mg · kg^−1 as a single bolus dose, and Group IV received an initial dose of rocuronium 0.06 mg · kg^−1 followed by rocuronium 0.54 mg · kg^−1. Group V received a priming dose of Mivacurium 0.015 mg · kg^−1 followed by rocuronium 0.54 mg · kg^−1. Group VI received an initial dose of rocuronium 0.06 mg · kg^−1 followed by Mivacurium 0.135 mg · kg^−1. Group VII received succinykholine 1.0 mg · kg^−1. Groups I, III, and VII received a placebo injection before the administration of the neuromuscular blocking drug. Additional thiopentone 2 mg · kg^−1 iv was given 30 sec before intubation. Onset times (mean (95% confidence interval)) after priming a rocuronium block with either rocuronium (73 (57–90) sec) or Mivacurium (58 (47–69) sec) were similar to those after succinykholine (54 (40–68) sec), and were shorter (P < 0.01) than that observed in other groups. Intubating conditions were not different between the groups. The duration of neuromuscular block was shortest with succinykholine. It is concluded that priming a rocuronium block with either Mivacurium or rocuronium resulted in a neuromuscular block comparable to that of succinykholine in both the onset of action and intubating conditions.

  • Neuromuscular Effects of Rocuronium Bromide and Mivacurium Chloride Administered Alone and in Combination
    Anesthesiology, 1994
    Co-Authors: Mohamed Naguib
    Abstract:

    BACKGROUND Rocuronium is a new nondepolarizing neuromuscular blocking agent with a rapid onset but with intermediate duration of action. Mivacurium, on the other hand, is a new short-acting nondepolarizing neuromuscular relaxant, but of slower onset of action. The current study was undertaken to characterize the interaction between rocuronium and Mivacurium. METHODS In the first study, the dose-response relations of rocuronium, Mivacurium, and their combination were studied in ASA physical status 1 or 2 patients during thiopental-fentanyl-N2O anesthesia. One hundred ten patients, randomly assigned to 1 of 11 groups of 10 patients each, received Mivacurium 30, 50, or 70 micrograms.kg-1; rocuronium 100, 200, 250, or 300 micrograms.kg-1; or an equieffective combination of both drugs (1 ED50 rocuronium + 1 ED50 Mivacurium; 1/2 ED50 rocuronium + 1/2 ED50 Mivacurium; 1/4 ED50 rocuronium + 1/4 ED50 Mivacurium; or 1/8 ED50 rocuronium + 1/8 ED50 Mivacurium, where ED50 is the dose producing 50% depression of the first twitch height). In the second study, 50 patients, ASA physical status 1 or 2, anesthetized with thiopental-fentanyl-N2O, were randomly allocated to 5 groups of 10 patients each to receive one of the following neuromuscular blocking drugs or drug combination: rocuronium 600 micrograms.kg-1 (group 1), Mivacurium 150 micrograms.kg-1 (group 2) rocuronium 150 micrograms.kg-1 + Mivacurium 37.5 micrograms.kg-1 (group 3), rocuronium 300 micrograms.kg-1 + Mivacurium 75 micrograms.kg-1 ((group 4), or rocuronium 600 micrograms.kg-1 + Mivacurium 150 micrograms.kg-1 (group 5). RESULTS The calculated ED50 values and their 95% confidence intervals were 125 (122-129) and 37 (36-38) micrograms.kg-1 for the rocuronium and Mivacurium groups, respectively. The interaction between rocuronium and Mivacurium was found to be synergistic. The measured ED50 of the mixture was only 62% of the predicted value assuming a purely additive interaction. In the second study, rocuronium 600 micrograms.kg-1 group and group 3 had similar onset times (99 [74-123] and 114 [100-128] s, respectively), which were significantly shorter than that observed in the Mivacurium 150 micrograms.kg-1 group (178 [149-206] s). Onset times in groups 4 and 5 were significantly shorter than that in each of the other study groups (69 [63-76] and 73 [65-80] s, respectively). Clinical duration of action (recovery of T1 to 25% of baseline twitch height) was significantly greater in group 5 (55 [51-60] min) than with all other doses and agents, and briefest (P < 0.01) with Mivacurium 150 micrograms.kg-1 (14.5 [12.6-16.5] min) and group 3 (14.7 [13.4-16] min). CONCLUSIONS The interaction between rocuronium and Mivacurium was found to be synergistic.

  • Different priming techniques, including Mivacurium, accelerate the onset of rocuronium.
    Canadian journal of anaesthesia = Journal canadien d'anesthesie, 1994
    Co-Authors: Mohamed Naguib
    Abstract:

    Different priming sequences of equipotent doses of rocuronium and Mivacurium on the onset of maximum neuromuscular block and intubating conditions were compared with those obtained after succinylcholine. During thiopentone-fentanylnitrous oxide anaesthesia, 70 patients were randomly assigned into seven groups. Group I received Mivacurium 0.15 mg · kg−1 as a single bolus dose. Group II received a priming dose of Mivacurium 0.015 mg · kg−1 followed three minutes later by Mivacurium 0.135 mg · kg−1. Group III received rocuronium 0.6 mg · kg−1 as a single bolus dose, and Group IV received an initial dose of rocuronium 0.06 mg · kg−1 followed by rocuronium 0.54 mg · kg−1. Group V received a priming dose of Mivacurium 0.015 mg · kg−1 followed by rocuronium 0.54 mg · kg−1. Group VI received an initial dose of rocuronium 0.06 mg · kg−1 followed by Mivacurium 0.135 mg · kg−1. Group VII received succinykholine 1.0 mg · kg−1. Groups I, III, and VII received a placebo injection before the administration of the neuromuscular blocking drug. Additional thiopentone 2 mg · kg−1 iv was given 30 sec before intubation. Onset times (mean (95% confidence interval)) after priming a rocuronium block with either rocuronium (73 (57–90) sec) or Mivacurium (58 (47–69) sec) were similar to those after succinykholine (54 (40–68) sec), and were shorter (P < 0.01) than that observed in other groups. Intubating conditions were not different between the groups. The duration of neuromuscular block was shortest with succinykholine. It is concluded that priming a rocuronium block with either Mivacurium or rocuronium resulted in a neuromuscular block comparable to that of succinykholine in both the onset of action and intubating conditions.

Leo H. D. J. Booij - One of the best experts on this subject based on the ideXlab platform.

  • a systematic review and meta regression analysis of Mivacurium for tracheal intubation
    Anaesthesia, 2014
    Co-Authors: L. E. H. Vanlinthout, S. H. Mesfin, Niel Hens, B. F. Vanacker, E.n. Robertson, Leo H. D. J. Booij
    Abstract:

    We systematically reviewed factors associated with intubation conditions in randomised controlled trials of Mivacurium, using random-effects meta-regression analysis. We included 29 studies of 1050 healthy participants. Four factors explained 72.9% of the variation in the probability of excellent intubation conditions: Mivacurium dose, 24.4%; opioid use, 29.9%; time to intubation and age together, 18.6%. The odds ratio (95% CI) for excellent intubation was 3.14 (1.65-5.73) for doubling the Mivacurium dose, 5.99 (2.14-15.18) for adding opioids to the intubation sequence, and 6.55 (6.01-7.74) for increasing the delay between Mivacurium injection and airway insertion from 1 to 2 min in subjects aged 25 years and 2.17 (2.01-2.69) for subjects aged 70 years, p < 0.001 for all. We conclude that good conditions for tracheal intubation are more likely by delaying laryngoscopy after injecting a higher dose of Mivacurium with an opioid, particularly in older people.

  • A systematic review and meta‐regression analysis of Mivacurium for tracheal intubation
    Anaesthesia, 2014
    Co-Authors: L. E. H. Vanlinthout, S. H. Mesfin, Niel Hens, B. F. Vanacker, E.n. Robertson, Leo H. D. J. Booij
    Abstract:

    We systematically reviewed factors associated with intubation conditions in randomised controlled trials of Mivacurium, using random-effects meta-regression analysis. We included 29 studies of 1050 healthy participants. Four factors explained 72.9% of the variation in the probability of excellent intubation conditions: Mivacurium dose, 24.4%; opioid use, 29.9%; time to intubation and age together, 18.6%. The odds ratio (95% CI) for excellent intubation was 3.14 (1.65-5.73) for doubling the Mivacurium dose, 5.99 (2.14-15.18) for adding opioids to the intubation sequence, and 6.55 (6.01-7.74) for increasing the delay between Mivacurium injection and airway insertion from 1 to 2 min in subjects aged 25 years and 2.17 (2.01-2.69) for subjects aged 70 years, p < 0.001 for all. We conclude that good conditions for tracheal intubation are more likely by delaying laryngoscopy after injecting a higher dose of Mivacurium with an opioid, particularly in older people.

Olli A. Meretoja - One of the best experts on this subject based on the ideXlab platform.

  • Potency and hourly maintenance requirement of combinations of Mivacurium and pancuronium in adults
    Canadian Journal of Anaesthesia, 1998
    Co-Authors: Pekka Rautoma, Olli Erkola, Olli A. Meretoja
    Abstract:

    Purpose To evaluate the dose-response and maintenance requirements of a combination of Mivacurium and pancuronium (cMP) in clinical practice. Methods In a randomised, open clinical study, 70 patients, 17–50 yr of age, were anaesthetised with propofol, alfentanil and nitrous oxide in oxygen. Thirty patients received Mivacurium and 20 patients received pancuronium to establish dose-response curves for these agents. Hourly maintenance requirements of Mivacurium and pancuronium to maintain 90–95% neuromuscular blockade (NMB) were determined. Thereafter, 20 additional patients received cMP in incremental doses to establish a cumulative dose-response curve for cMP followed by maintenance doses of cMP NMB was recorded by adductor pollicis electromyography. Results The ED_95 values for Mivacurium and pancuronium were 100 and 66μg·kg^−1, respectively; and for the cMP 2:1 (in mg:mg basis), 32 μg·kg^−1 Mivacurium together with 16 μg·kg^−1 pancuronium. This cMP was 1.8 times more potent than one parent agent ( P < 0.0001 ). When cMP 2:1 was used, 60% of normal maintenance requirement of pancuronium reduced the requirement of Mivacurium by > 90%. If cMP 20:1 was used, then 20% of normal maintenance requirement of pancuronium reduced the requirement of Mivacurium by > 70%. Neostigmine 35 μg·kKg^−1 given at T_1 10% recovery following cMP reversed the NMB to a TOF ratio of 0.70 in 9.5 ±3.9 min. Conclusion These results reflect considerable synergism between Mivacurium and pancuronium. The cMP is near intermediate-acting and the NMB is easily reversed with neostigmine. By using cMR it may be possible to save some pharmacological costs during maintenance of anaesthesia. Objectif Évaluer les besoins dose-réponse de même que les besoins d’entretien d’un mélange Mivacurium et pancuronium (cMP) en pratique clinique. Méthodes Dans une étude clinique ouverte et aléatoire, 70 patients âgés de 17 à 50 ans ont été anesthésiés avec propofol, alfentanil, N_2O et O_2. Trente patients ont reçu du Mivacurium et 20 patients ont reçu du pancuronium pour construire des courbes dose-réponse pour les deux médicaments. On a ensuite déterminé les besoins horaires de Mivacurium et de pancuronium pour maintenir un bloc neuro-musculaire (BNM) à 90–95%. Par la suite, 20 patients supplémentaires ont reçu le cMP en doses croissantes pour établir une courbe dose-réponse cumulative pour le cMR suivi de doses de maintien de cMP Le bloc a été enregistré par électromyographie de l’adducteur du pouce. Résultats Les valeurs ED_95 pour le Mivacurium et le pancuronium ont été respectivement de 100 et 66 μg·kg^−1; et pour le mélange cMP, en rapport 2:1 sur la base de mg:mg, 32 μg·kg^−1 pour le Mivacurium et 16 μg^−1kg pour le pancuronium. Cette combinaison cMP a été 1,8 fois plus puissante que chacun des agents constituants ( P < 0,000l). Lorsqu’on a utilisé le cMP 2:1, 60% de la dose d’entretien normale de pancuronium a réduit les besoins de Mivacurium de > 90%. Si on utilisait un mélange cMP 20:1, 20% de la dose de maintien normale de pancuronium réduisait les besoins de Mivacurium de > 70%. La néostigmine 35 μg·kg^−1 administrée lorsque le bloc produit par cMP avait récupéré à une valeur T_1 = 10% entraînait une récupération du BNM évalué par le train-de-quatre de 0,70 en 9.5 ± 3.9 min. Conclusion Ces résultats indiquent une synergie considérable entre le Mivacurium et le pancuronium. Le mélange cMP se comporte presque comme un relaxant musculaire de durée intermédiaire dont le bloc est facilement antagonisé par la néostigmine. Par l’utilisation du cMR il est possible de faire des économies quant aux coûts des médicaments durant le maintien de l’anesthésie.

  • The pharmacodynamics of Mivacurium preceded by atracurium or cisatracurium in children.
    Anesthesia and analgesia, 1998
    Co-Authors: Larisa Jalkanen, Pekka Rautoma, Tomi Taivainen, Olli A. Meretoja
    Abstract:

    UNLABELLED We evaluated whether Mivacurium maintains its short duration of effect when preceded by atracurium or cisatracurium in 45 children during propofol/alfentanil/N2O/O2 anesthesia. Neuromuscular response was recorded by using an adductor pollicis electromyogram (EMG). Children were randomized to receive two doses of atracurium (350 micrograms/kg and 70 micrograms/kg in Group AM), cisatracurium (64 micrograms/kg and 10 micrograms/kg in Group CM), or Mivacurium (200 micrograms/kg and 100 micrograms/kg in Group MM), followed by a final dose of Mivacurium 100 micrograms/kg. The second and third doses of the muscle relaxants were administered at 25% EMG recovery. After the final dose of Mivacurium, the times to 95% of EMG recovery in groups AM, CM, and MM were (median with 10-90 percentile range) 33.0 (28.0-40.0) min, 30.7 (26.0-40.3) min, and 10.3 (8.0-14.0) min, respectively (P < 0.0001). The recovery times to a train-of-four ratio of 0.70 were 30.3 (24.7-37.0) min, 28.0 (24.7-37.7) min, and 10.3 (8.0-13.7) min for groups AM, CM, and MM, respectively (P < 0.0001). Thus, the duration of effect of Mivacurium was prolonged by 200% if preceded by either atracurium or cisatracurium. IMPLICATIONS We compared the pharmacodynamics of Mivacurium given alone or preceded by atracurium or cisatracurium in children. The duration of effects of Mivacurium was prolonged by 200% if preceded by either atracurium or cisatracurium. This implies that Mivacurium has a short duration of effect only when given as a single relaxant.

  • Mivacurium When Precedent by Pancuronium Becomes a Long-acting Muscle Relaxant
    Anesthesiology, 1996
    Co-Authors: Olli Erkola, Pekka Rautoma, Olli A. Meretoja
    Abstract:

    BACKGROUND To ensure rapid recovery of neuromuscular block, it might be useful to administer a short-acting relaxant after a long-acting one. Therefore, the interaction between pancuronium and Mivacurium was investigated when Mivacurium was administered during the recovery from pancuronium block. METHODS After written informed consent, 41 adult patients were studied during propofol/alfentanil/nitrous oxide/oxygen anesthesia. Neuromuscular function was monitored using an electromyographic (EMG) method. AFter a stable EMG calibration response, cumulative doses of pancuronium were given to establish a 95% neuromuscular block. In the control group, and ED95 dose of 100 microg/kg Mivacurium was administered instead of pancuronium. When the EMG response after pancuronium or Mivacurium had recovered to 25% of the baseline, a single randomized intravenous bolus dose of 10 or 70 microg/kg Mivacurium was given. Thereafter, spontaneous recovery of the neuromuscular function was recorded. RESULTS The time from pancuronium until T1 25% EMG recovery was 38 +/- 12 min (mean +/- SD). The respective times after 10 or 70 microg/kg Mivacurium were 28 +/- 8 and 54 +/- 7 min in the pancuronium group or 3 +/- 1 (n=3) and 10 +/- 4 min in the Mivacurium group (P=0.0001). Times to 95% EMG recovery after 10 or 70 microgm/kg Mivacurium were 77 +/- 14 and 97 +/- 16 min in the pancuronium group and 11 +/- 3 and 20 +/- 7 min in the Mivacurium group, respectively (P

  • Interaction between Mivacurium and succinylcholine
    Anesthesia and analgesia, 1995
    Co-Authors: Olli Erkola, Pekka Rautoma, Olli A. Meretoja
    Abstract:

    We investigated the interaction between Mivacurium and succinylcholine when Mivacurium was administered during the early recovery from succinylcholine block. We studied 40 adult patients during propofol-alfentanil-N2O-O2 anesthesia. Neuromuscular function was monitored using an electromyographic method (Relaxograph, Datex, Helsinki, Finland). Patients randomly received either 1.0 mg/kg of succinyl-choline followed by 0.15 mg/kg of Mivacurium when the first twitch (T1) during succinylcholine block recovered to 5%, or 0.15 mg/kg of Mivacurium without succinylcholine. Serum cholinesterase activity was lower than normal range in two patients and higher than normal range in four patients, but the dibucaine number value was normal in every patient. The mean onset time (3.8 +/- 0.9 min) (mean +/- SD) or maximal neuromuscular block (96.6% +/- 7.2%) of Mivacurium did not differ between the groups. The T1 recovery times of Mivacurium were slightly shorter (P < 0.05) after succinylcholine administration than without it. During recovery of Mivacurium block, the fade was significantly greater, i.e., the train-of-four (TOF) ratio was lower, after succinylcholine administration than without it. Recovery index (T1 25%-75%, mean 4.7 +/- 1.3 min) and the time from the administration of Mivacurium to the recovery of TOF ratio 0.7 (mean 20.4 +/- 5.1 min) were not different between the groups. In conclusion, in healthy patients succinylcholine has negligible effects on a subsequent Mivacurium-induced neuromuscular block.

  • Mivacurium chloride in infants and children
    Acta Anaesthesiologica Scandinavica, 1995
    Co-Authors: Olli A. Meretoja, Tomi Taivainen
    Abstract:

    Mivacurium has been little studied in infants and children without a volatile anaesthetic agent. We analysed onset time and maximal neuromuscular response after Mivacurium 0.1 mg/kg, and the infusion requirement of Mivacurium to maintain a 50, 90, or 95% neuromuscular block in 76 infants and children under N2O-O2-alfentanil anaesthesia. Furthermore, we assessed the time course of potentiation of 1 MAC end-tidal halothane or isoflurane on the infusion requirement of Mivacurium. Neuromuscular response was recorded by adductor pollicis electromyogram. The onset time of Mivacurium was shorter in infants than in children (2.1 +/- 0.6 and 3.2 +/- 0.9 min (mean +/- SD); P = 0.0001). The dose potency of Mivacurium did not depend on the age of a paediatric patient. The estimated ED95 of Mivacurium was 136 +/- 46 micrograms/kg. The Mivacurium requirement to maintain a 50, 90, or 95% neuromuscular block averaged 340, 730, and 900 micrograms/kg/h, respectively. Halothane and isoflurane decreased this hourly requirement by 35 and 70%, respectively. The decrease in the Mivacurium infusion requirment was fastest in the youngest children. In conclusion, Mivacurium is easy to administer as bolus doses or continuous infusion in paediatric patients because its potency is similar in all patients from 1 month to 15 years of age. Halothane and isoflurane produce their maximal potentiation of neuromuscular block only after 30-60 min of administration. This potentiation is similar in magnitude in all patients, but takes place fastest in the youngest children.

Dennis M. Fisher - One of the best experts on this subject based on the ideXlab platform.

  • Effect of edrophonium and neostigmine on the pharmacokinetics and neuromuscular effects of Mivacurium.
    Anesthesiology, 2000
    Co-Authors: Janos Szenohradszky, Ronald T. Brown, Manohar Sharma, Declan Fogarty, Hans Kirkegaard-nielsen, Dennis M. Fisher
    Abstract:

    BACKGROUND Previous studies demonstrated that both edrophonium and neostigmine affect Mivacurium's pharmacokinetics, thereby potentially affecting its recovery profile. However, those studies were not clinically relevant because Mivacurium was still infused after the antagonists were given. In the present study, the authors gave antagonists (or placebo) after discontinuing a Mivacurium infusion, thereby obtaining data that are more clinically relevant. METHODS In 18 patients, Mivacurium was infused at 10 microg kg(-1) x min(-1) for 40 min, the infusion was discontinued for 15 min and then restarted at the same rate for another 40 min. Patients were randomized to receive 500 microg/kg edrophonium, 50 microg/kg neostigmine, or saline at discontinuation of the second infusion; all subjects received 1 mg atropine. Plasma was sampled during the final 10 min of each infusion to determine steady state Mivacurium concentrations and for 15 min after each infusion. Twitch tension was recorded. Mivacurium concentrations after each of the two infusions were compared. RESULTS After discontinuation of the second infusion, Mivacurium concentrations were larger than those after the first infusion at 2 min with edrophonium and at 2, 4, and 7 min with neostigmine. With both neostigmine and edrophonium, twitch tension recovered after infusion #2 more rapidly than after infusion #1; however, the magnitude of this effect was small CONCLUSION Edrophonium transiently slows the rate at which Mivacurium concentrations decrease; this is consistent with our previous findings. Neostigmine has a similar, although longer, effect. Despite altering Mivacurium's elimination characteristics, both drugs facilitate neuromuscular recovery, although their benefit is small.

  • Does age or pseudocholinesterase activity predict Mivacurium infusion rate in children
    Anesthesia & Analgesia, 1996
    Co-Authors: Dorothea A. Markakis, Paul S. Hart, Marie Lau, Ronald T. Brown, Dennis M. Fisher
    Abstract:

    Previous studies have suggested that the Mivacurium infusion rate to maintain target twitch depression is greater in children than in adults, and that there is only a limited relationship between pseudocholinesterase activity and Mivacurium infusion rate in children.We therefore examined whether Mivacurium infusion rates are larger in children than in adults, and whether pseudocholinesterase activity influences Mivacurium infusion rate in children. In 20 children aged 1-9 yr, mechanical twitch response to ulnar nerve train-of-four stimulation was measured; concurrent data were obtained in 14 adults aged 18-58 yr. All patients were anesthetized with N2 O and isoflurane, 0.75 minimum alveolar anesthetic concentration (MAC) (age-adjusted). Mivacurium was infused at constant rates for > 15 min targeting 50% and 90% twitch depression. The Hill Equation wasfit to the resulting values for twitch depression versus Mivacurium infusion rate to predict infusion rates producing 50% and 90% twitch depression (IR50 and IR90, respectively). The relationship of IR50 and IR90 to pseudocholinesterase activity was determined by linear regression; values for children and adults were compared by analysis of covariance. For children, IR50 (r2 = 0.22, P = 0.038) but not IR90 (r2 = 0.11 P = 0.21) was related to pseudocholinesterase activity. Infusion rates were approximately twice as large in children as in adults. We confirm that Mivacurium infusion rates are larger in children than in adults and demonstrate a relationship between pseudocholinesterase activity and infusion rates. (Anesth Analg 1996;82:39-43)

  • The effect of neostigmine on twitch tension and muscle relaxant concentration during infusion of Mivacurium or vecuronium.
    Anesthesiology, 1995
    Co-Authors: Janos Szenohradszky, Marie Lau, Ronald T. Brown, Manohar Sharma, Dennis M. Fisher
    Abstract:

    Background : An investigation suggested that neostigmine may not effectively antagonize Mivacurium, presumably because neostigmine impairs Mivacurium's metabolism. However, the effect of neostigmine on Mivacurium's metabolism in vivo has not been reported. Therefore, the effect of neostigmine on neuromuscular function and plasma Mivacurium concentrations during constant Mivacurium infusion was determined. Methods : Mivacurium was infused in five patients to maintain 90% depression of adductor pollicis twitch tension, then 50 μg/kg intravenous neostigmine was administered without altering the Mivacurium infusion. Peak twitch tension after neostigmine, plasma cholinesterase activity, and Mivacurium concentrations before and after neostigmine were measured. Five additional patients were given 50 μg/kg neostigmine to antagonize block due to continuous infusions of vecuronium. Results : Neostigmine produced less antagonism of Mivacurium (39 ± 11%) than of vecuronium (54 ± 9%, P < 0.05). Neostigmine decreased plasma cholinesterase activity and increased plasma concentrations of the trans-trans and cis-trans stereoisomers of Mivacurium (P < 0.05). Conclusions : Neostigmine is less effective at antagonizing the neuromuscular effect of Mivacurium than that of vecuronium during constant infusion. Neostigmine increases plasma Mivacurium concentrations, likely explaining its limited efficacy. Out results confirm that neostigmine impairs the metabolism of Mivacurium in vivo and may explain the observation that neostigmine may not effectively antagonize Mivacurium-induced block. (Key words : Antagonists, neuromuscular: neostigmine. Enzymes : cholinesterase ; plasma. Neuromuscular relaxants, nondepolarizing : Mivacurium.)

  • Edrophonium increases Mivacurium concentrations during constant Mivacurium infusion, and large doses minimally antagonize paralysis.
    Anesthesiology, 1995
    Co-Authors: Paul S. Hart, Marie Lau, Ronald T. Brown, Peter Wright, Manohar Sharma, Ronald D. Miller, Larry D. Gruenke, Dennis M. Fisher
    Abstract:

    BACKGROUND: Mivacurium, a nondepolarizing muscle relaxant, is metabolized by plasma cholinesterase. Although edrophonium does not alter plasma cholinesterase activity, we have observed that doses of edrophonium that antagonize paralysis from other nondepolarizing muscle relaxants are less effective with Mivacurium. We speculated that edrophonium might after metabolism of Mivacurium, thereby hindering antagonism of paralysis. Accordingly, we determined the effect of edrophonium on neuromuscular function and plasma Mivacurium concentrations during constant Mivacurium infusion. METHODS: We infused Mivacurium to maintain 90% depression of adductor pollicis twitch tension and then gave edrophonium in doses ranging from 125-2,000 micrograms/kg without altering the Mivacurium infusion. Peak twitch tension after edrophonium was determined to estimate the dose of edrophonium antagonizing 50% of twitch depression for antagonism of Mivacurium; plasma cholinesterase activity and Mivacurium concentrations before and after edrophonium were measured. Additional subjects were given 500 micrograms/kg edrophonium to antagonize continuous infusions of d-tubocurarine and vecuronium. RESULTS: With Mivacurium, edrophonium increased twitch tension in a dose-dependent manner: the dose of edrophonium antagonizing 50% of twitch depression was 2,810 micrograms/kg. The largest dose of edrophonium (2,000 micrograms/kg) produced only 45 +/- 7% antagonism. Edrophonium, 500 micrograms/kg, antagonized Mivacurium markedly less than it antagonized d-tubocurarine and vecuronium. Edrophonium increased plasma concentrations of the two potent stereoisomers of Mivacurium 48% and 79%, these peaking at 1-2 min; plasma cholinesterase activity was unchanged. CONCLUSIONS: Edrophonium doses that antagonize d-tubocurarine and vecuronium are less effective in antagonizing the neuromuscular effects of Mivacurium during constant infusion. Edrophonium increases plasma Mivacurium concentrations, partly or completely explaining its limited efficacy; the mechanism by which edrophonium increases Mivacurium concentrations remains unexplained. Our results demonstrate that antagonism of Mivacurium by edrophonium is impaired, and therefore we question whether edrophonium should be used to antagonize Mivacurium.

  • Is intramuscular Mivacurium an alternative to intramuscular succinylcholine
    Anesthesiology, 1994
    Co-Authors: Charles B. Cauldwell, Marie Lau, Dennis M. Fisher
    Abstract:

    BACKGROUND Mivacurium's rapid onset and short duration of action in children suggests that intramuscular administration might treat laryngospasm and facilitate tracheal intubation without producing prolonged paralysis. Accordingly, the authors measured the neuromuscular effects of intramuscular Mivacurium in anesthetized infants and children. METHODS Twenty unpremedicated infants and children (3 months to 5 yr of age) were anesthetized with nitrous oxide and halothane and permitted to breathe spontaneously. When anesthetic conditions were stable, Mivacurium was injected into the quadriceps or deltoid muscle. Minute ventilation and adductor pollicis twitch tension were measured. The initial Mivacurium dose was 250 micrograms/kg and was increased (to a maximum of 800 micrograms/kg, at which dose the trial was ended) or decreased according to the response of the previous patient, the goal being to bracket the dose producing 80-90% twitch depression within 5 min of drug administration. RESULTS No patient achieved > 80% twitch depression within 5 min of Mivacurium administration. Peak twitch depression was 90 +/- 13% (mean +/- SD) for infants and 88 +/- 15% for children at 15.0 +/- 4.6 min and 18.4 +/- 6.4 min, respectively. Ventilatory depression (a 50% decrease in minute ventilation or a 10-mmHg increase in end-tidal carbon dioxide tension) occurred at 9.0 +/- 4.4 min in nine infants and 13.6 +/- 7.5 min in 10 children; ventilatory depression did not develop in one infant given a dose of 350 micrograms/kg. Time to peak twitch depression or ventilatory depression was not faster with larger doses. CONCLUSIONS Although ventilatory depression preceded twitch depression, both occurred later with intramuscular Mivacurium than would be expected after intravenous Mivacurium or intramuscular succinylcholine. The authors speculate that the onset of intramuscular Mivacurium is too slow to treat laryngospasm or to facilitate routine tracheal intubation in infants or children, despite administration of large doses.

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  • COMPARISON OF Mivacurium AND SUXAMETHONIUM ADMINISTERED BY BOLUS AND INFUSION
    2016
    Co-Authors: Barbara W. Brandom, Susan K Woelfel, S. Weber, D. M. Powers, Ryan D. Cook, J N Weakly
    Abstract:

    Mivacurium chloride (BW B1090U), a new short-acting non-depolarizing neuromuscular blocking drug, has undergone initial clinical trials to evaluate its neuromuscular and cardiovascular effects [1-7]. Mivacurium is metabolized by pseudocholinesterase at a rate 70 % of that of suxamethonium [8]. Because of its relatively short duration of action, Mivacurium may be useful as a bolus to facilitate tracheal intubation and as an infusion to maintain extended neuromuscular block. This study of healthy adult patients undergoing surgery was designed to compare the onset of neuromuscular block and the ease of tracheal intubation after near equipotent bolus doses of Mivacurium or suxamethonium, to define the infusion requirements and recovery pattern following cessation of Mivacurium or suxa-methonium infusion, and to test the predictive value of the time to recovery of 5 % neuro-muscular transmission (75) after an initial bolus in determining the infusion requirements for miva-curium or suxamethonium. PATIENTS AND METHODS We studied 30 healthy adults (ASA physical status I or II) aged 18-57 yr. All patients underwent low to moderate risk elective surgical procedures requiring tracheal intubation. Wome

  • Neuromuscular effects of rapacuronium in pediatric patients during nitrous oxide-halothane anesthesia: comparison with Mivacurium
    Canadian Journal of Anaesthesia, 2000
    Co-Authors: Barbara W. Brandom, Susan K Woelfel, George B. Bikhazi, Charbel A. Kenaan, Judith O. Margolis, Allison K. Ross, Brian Ginsberg, Guy De L. Dear, John B. Eck, Mark E. Lloyd
    Abstract:

    Purpose: To describe neuromuscular effects of rapacuronium in pediatric patients during N_2 O-halothane anesthesia and compare them with Mivacurium in children. Methods: 103 pediatric patients, seven days- 12 yr, received rapacuronium or Mivacurium during N_2 O-halothane anesthesia. Onset and recovery of block were measured using EMG (Datex). Block was compared between groups based on drug treatment and age. Children < two years received 1 or 2 mg·kg^−1 rapacuronium: 2 – 12 yr received either 2 mg·kg^−1 or 3 mg·kg^−1 rapacuronium, or 0.2 mg·kg^−1 Mivacurium. Results: There were no differences in onset (1.7±1.8 min) or maximum block (T1 2.4±8%) among neonates, infants, and toddlers after either dose of rapacuronium. There was no difference between 1 and 2 mg·kg^−1 of rapacuronium block at 60 sec. Train-of-four ratio (T4/T1)>0.7 occurred later after 2 mg·kg^−1 than 1 mg·kg^−1 in these patients ( P 0.7 occurred 10 to 11 min later after this dose of rapacuronium than after Mivacurium. Conclusion: Rapacuronium produces block earlier than Mivacurium. Recovery from rapacuronium block is dose related and slower than that following Mivacurium during halothane anesthesia. Objectif: Décrire les effets neuromusculaires du rapacuronium pendant l’anesthésie avec N_2O et halothane et les comparer avec ceux du Mivacurium chez des enfants. Méthode: Cent trois enfants, de 7 jrs à 12 ans, ont reçu du rapacuronium ou du Mivacurium pendant une anesthésie avec N_2O et halothane. Le début et la fin du bloc ont été mesurés à l’aide de l’EMG (Datex). Le bloc a été comparé sur la base du traitement médicamenteux et de l’âge. Les enfants 0,7 s’est produit plus tard après 2 mg·kg^−1 qu’après 1 mg·kg^−1 ( P 0,7 sont survenus de 10–11 min plus tard après cette dose de rapacuronium qu’après le Mivacurium. Conclusion: Le rapacuronium agit plus rapidement que le Mivacurium. Pendant l’anesthésie avec de l’halothane, le renversement du bloc suivant l’utilisation de rapacuronium est relié à la dose et est plus lent que celui qui suit le Mivacurium.

  • synergism between atracurium and Mivacurium compared with that between vecuronium and Mivacurium
    Anesthesia & Analgesia, 1994
    Co-Authors: Larisa Jalkanen, Barbara W. Brandom, O A Meretoja, T Taivainen, Bimal Dayal
    Abstract:

    Synergism exists between some combinations of nondepolarizing muscle relaxants. To test the possibility of synergism between Mivacurium and atracurium or vecuronium, 60 children anesthetized with propofol-alfentanil-N2O-O2 were randomized to one of five groups. Three groups of 10 patients each received an ED50 dose of a parent drug atracurium (A), vecuronium (V), or Mivacurium (M), respectively, and two other groups of 15 patients each received a single-dose combination of atracurium with Mivacurium (cAM) or vecuronium with Mivacurium (cVM). Dose combinations constituted 0.5 times an ED50 dose of each drug. Neuromuscular response was monitored by adductor pollicis electromyogram (EMG). Maximum neuromuscular block (NMB) established by a single parent drug did not differ between the groups or from 50% NMB. It averaged 5.03 +/- 0.12 probits (51.2% NMB). On the contrary, maximum NMB established by the two-dose combinations, cAM or cVM, was significantly more than NMB produced by either single parent drug of the particular combination (cAM vs A or M; P = 0.0035, and cVM vs V or M; P = 0.0004) without a statistically significant difference between groups cAM and cVM. Maximum NMB established by combinations averaged 6.15 +/- 0.21 probits (87.5% NMB). The onset of maximum NMB for Mivacurium was significantly faster compared to that for atracurium or for vecuronium (2.8 +/- 0.3 vs 5.7 +/- 0.4 or 4.0 +/- 0.3 min, respectively; P = 0.0001). Our results indicate that both drug combinations are synergistic even though only vecuronium is markedly different in its molecular structure from Mivacurium.

  • accelerated onset and delayed recovery of neuromuscular block induced by Mivacurium preceded by pancuronium in children
    Anesthesia & Analgesia, 1993
    Co-Authors: Barbara W. Brandom, O A Meretoja, T Taivainen, Kari Wirtavuori
    Abstract:

    The goal of this study was to describe a technique which could shorten the time from Mivacurium administration to peak neuromuscular block (NMB) after administration of the maximum recommended dose of Mivacurium. Forty-eight pediatric patients were randomized into three groups and studied during nitrous oxide-alfentanil-thiopental anesthesia. Every patient received two blinded injections 3 min apart: either 15 micrograms/kg of pancuronium in 1 mL of saline followed by 170 or 200 micrograms/kg of Mivacurium or saline followed by 200 micrograms/kg of Mivacurium. Intravenous induction of anesthesia followed the first injection. Thenar electromyogram response to supramaximum train-of-four stimulation of the ulnar nerve at 10-s intervals was used for neuromuscular monitoring. Pretreatment with pancuronium significantly shortened the time to NMB and prolonged spontaneous recovery from NMB in comparison to the temporal course of NMB after administration of 200 micrograms/kg of Mivacurium. Time from injection to 90% NMB averaged 116 (SEM 11) s after administration of 200 micrograms/kg of Mivacurium, and 71 (7) s and 94 (11) s when 200 micrograms/kg or 170 micrograms/kg of Mivacurium, respectively, was preceded by pancuronium (P = 0.0095). Mean times from injection to recovery of neuromuscular function to > 25% of baseline (T25) and to train-of-four ratio of 0.75 were 9.1 (0.7) and 15.8 (1.2) min, respectively, after administration of 200 micrograms/kg of Mivacurium alone. T25 and train-of-four of 0.75 occurred significantly later at 21.9 (1.8) and 35.0 (2.8) min, respectively (P = 0.0001), when 200 micrograms/kg of Mivacurium was preceded by 15 micrograms/kg of pancuronium.(ABSTRACT TRUNCATED AT 250 WORDS)