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Biomedical subjects

M Naguib

Publications and source records attributed to M Naguib.

At least 73 records · Page 4Linked to original sources
PubMed1994

Dose-response relationships for edrophonium and neostigmine antagonism of pipecuronium-induced neuromuscular block.

We have studied the dose-response relationships for neostigmine and edrophonium during antagonism of neuromuscular block induced by pipecuronium bromide. Fifty-six ASA physical status I or II adults were given pipecuronium 70 micrograms/kg during fentanylthiopental-nitrous oxide-halothane anesthesia. Train-of-four (TOF) stimulation was applied to the ulnar nerve every 10 s, and the force of contraction of the adductor pollicis muscle was recorded. When spontaneous recovery of first twitch height reached 20% of its initial control value, edrophonium (0.125, 0.25, 0.75, or 1 mg/kg) or neostigmine (0.015, 0.03, 0.045, or 0.06 mg/kg) was administered by random allocation. Neuromuscular function in another seven subjects was allowed to recover spontaneously. This study demonstrated that the dose-response curves for these two drugs for reversal of first twitch and TOF ratio were not parallel. The doses of neostigmine required to achieve 50% (ED50) and 80% (ED80) recovery of the first twitch after 10 min were 8.5 (7.3-9.7) and 17.4 (16.2-18.7) microgram/kg [mean (95% confidence intervals)], respectively. Corresponding ED50 and ED80 values for endrophonium were 84.1 (72.9-96.9) and 233 (215.7-253.3) microgram/kg, respectively. These values corresponded to neostigmine:edrophonium potency ratios of 9.89 (7.4-12.3) and 13.4 (11.8-14.9) for first twitch ED50 and ED80 height, respectively. The calculated doses producing 50% (ED50) recovery of the TOF ratio at 10 min were 18.8 (17.5-20.2) and 271.3 (246.5-298.6) microgram/kg for neostigmine and edrophonium, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Vascular malformation of the internal auditory canal.

A report of a case with a vascular malformation of the internal auditory canal (IAC) is presented. A review of the literature of this rather rare lesion is also made in an attempt to outline its clinical features, radiological diagnosis and management. The differential diagnosis and distinction between vascular malformations and other internal auditory canal tumours are discussed.

Adult↗
PubMed1993

Isobolographic and dose-response analysis of the interaction between pipecuronium and vecuronium.

We have studied the neuromuscular effects of pipecuronium, vecuronium and their combination in 130 ASA group I or II patients. Patients were anaesthetized with 0.8% halothane and 60% nitrous oxide in oxygen. Neuromuscular block was recorded as the evoked thenar mechanomyographic response to train-of-four stimulation of the ulnar nerve (2 Hz at 10-s intervals). The dose-response curves were determined by probit analysis. The calculated doses producing 50% depression of the first twitch height were 15.6, 16.9 and 15.0 micrograms kg-1 for the pipecuronium, vecuronium and pipecuronium-vecuronium combination groups, respectively. Isobolographic and algebraic (fractional) analyses were used to assess quantitatively the combined neuromuscular effect of pipecuronium and vecuronium and to define the type of interaction between these drugs. The interaction between pipecuronium and vecuronium was found to be additive.

Adolescent↗
PubMed1993

Dose-response relationships for edrophonium and neostigmine antagonism of mivacurium-induced neuromuscular block.

We have studied the dose-response relationships for neostigmine and edrophonium during antagonism of neuromuscular block induced by mivacurium chloride. Sixty-four ASA group I or II adults were given mivacurium 0.15 mg kg-1 during fentanyl-thiopentone-nitrous oxide-isoflurane anaesthesia. Train-of-four stimulation (TOF) was applied to the ulnar nerve every 10 s, and the force of contraction of the adductor pollicis muscle was recorded. When spontaneous recovery of first twitch height reached 10% of its initial control value, edrophonium 0.1, 0.2, 0.4, or 1 mg kg-1 or neostigmine 0.005, 0.01, 0.02, or 0.05 mg kg-1 was administered by random allocation. Neuromuscular function in another 16 subjects was allowed to recover spontaneously. Spontaneous recovery from 90% mivacurium block to 95% twitch height and TOF ratio 0.75 occurred within 15 min. This study demonstrated that the dose-response curves for these two drugs for antagonism of neuromuscular block (first twitch and train-of-four ratio) were parallel. The doses of neostigmine required to achieve 50% (ED50) and 70% (ED70) recovery of the first twitch after 10 min were 2 (1.5-2.5) micrograms kg-1 and 4.7 (4.1-5.4) micrograms kg-1 (mean (95% confidence intervals)), respectively. Corresponding ED50 and ED70 values for edrophonium were 2.8 (0.75-10.2) micrograms kg-1 and 9.2 (3.6-23.6) micrograms kg-1, respectively. These values corresponded to neostigmine:edrophonium potency ratios of 1.4 (0.4-2.4) and 1.95 (0.9-2.9) for first twitch ED50 and ED70 height, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Dose-response relationships for edrophonium and neostigmine antagonism of rocuronium bromide (ORG 9426)-induced neuromuscular blockade.

BACKGROUND: Rocuronium bromide (ORG 9426) is a new nondepolarizing muscle relaxant with a rapid onset but an intermediate duration of action. The dose-response relationships for neostigmine and edrophonium were studied during antagonism of neuromuscular block induced by rocuronium bromide. METHODS: Sixty-four ASA physical status 1 or 2 adults were given 0.6 mg/kg rocuronium bromide during thiopental-fentanyl-nitrous oxide-isoflurane anesthesia. Train-of-four (TOF) stimulation was applied to the ulnar nerve every 10 s, and the force of contraction of the adductor pollicis muscle was recorded. When spontaneous recovery of first twitch height reached 10% of its initial control value, edrophonium (0.1, 0.2, 0.4, or 1 mg/kg) or neostigmine (0.005, 0.01, 0.02, or 0.05 mg/kg) was administered by random allocation. Neuromuscular function in another eight subjects was allowed to recover spontaneously. Assisted recovery was defined as actual recovery minus mean spontaneous recovery in patients who were not given antagonists. RESULTS: The dose-response curves for neostigmine- and edrophonium-assisted antagonism of rocuronium bromide neuromuscular blockade for the single twitch and TOF ratio were not parallel. The doses of neostigmine required to achieve 50% and 80% recovery (ED50 and ED80, respectively) of the first twitch after 10 min were 0.017 (0.001) and 0.033 (0.001) mg/kg (mean (standard error of estimate for the mean)), respectively. Corresponding ED50 and ED80 values for edrophonium were 0.161 (0.001) and 0.690 (0.001) mg/kg, respectively. These values corresponded to neostigmine:edrophonium potency ratios of 9.5 (0.56) and 21 (0.67) for first twitch ED50 and ED80 height, respectively. The calculated doses producing ED50 of the TOF ratio at 10 min were 0.017 (0.001) and 0.469 (0.001) mg/kg for neostigmine and edrophonium, respectively. These values corresponded to a potency ratio of 27.5 (1.66). CONCLUSIONS: Under the conditions described in this study, if reversal was attempted at 10% first twitch recovery, edrophonium was less capable than neostigmine of reversing fade (potency ratio of 19.2 and 27.5 at 5 and 10 min, respectively) than first twitch (potency ratio of 6.7 and 9.5 at 5 and 10 min, respectively) during antagonism of rocuronium bromide-induced blockade. Edrophonium was found to be less effective than neostigmine at reversing rocuronium bromide-induced TOF fade.

Adult↗
PubMed1993

A prospective evaluation of the hepatotoxicity of lofepramine in the elderly.

Lofepramine has been acclaimed as an effective and safe antidepressant, particularly for the elderly. Recent case reports of hepatic toxicity following treatment with lofepramine, however, caused clinicians to question its use in a patient population who frequently have concomitant physical illness. From published data the incidence of serious side effects as well as the implications for its use remain unclear. In this study, 52 patients over the age of 65 years treated with lofepramine were monitored over a 12-week period. The results suggest that for the overwhelming majority of patients, any rise in liver enzyme activity is transient. It is recommended, however, that LFTs be monitored for the first 12 weeks of treatment.

Aged↗
PubMed1992

Induction dose-responses studies with propofol and thiopentone.

The relative potencies of propofol and thiopentone were assessed using different indicators of induction of anaesthesia: abolition of the response to verbal commands and eyelash stimulation. Log-probit dose-response curves for these end-points were determined 30, 60 and 90 s after induction in 96 unpremedicated ASA group I patients. For propofol, ED50 values for abolition of the response to verbal commands and eyelash stimulation at different time intervals were in the ranges 1.16-1.42 and 1.23-1.72 mg kg-1, respectively; corresponding ED95 values were 2.18-2.67 and 2.42-3.27 mg kg-1, respectively. For thiopentone, the calculated ED50 values for verbal commands and eyelash stimulation at the same time intervals were 1.81-2.23 and 3.55-3.40 mg kg-1; corresponding ED95 values were 5.11-6.29 and 6.41-6.70 mg kg-1, respectively. The potency ratio of propofol to thiopentone observed in this study varied from 1:1.27 to 1:2.88. It is concluded that a dose-response curve reflecting one end-point of anaesthesia cannot be used to define another end-point of anaesthesia.

Adult↗
PubMed1992

Pipecuronium-induced neuromuscular blockade during nitrous oxide-fentanyl, enflurane, isoflurane, and halothane anesthesia in surgical patients.

This study was designed to determine the capacity of several anesthetics to augment pipecuronium neuromuscular blockade. The potency of pipecuronium was determined with single-bolus administration of 20-50 micrograms/kg in 160 patients. Patients were anesthetized with N2O/O2 (60:40) supplemented with fentanyl (4-5 micrograms/kg), halothane (0.8%), isoflurane (1.2%), or enflurane (1.7%). Neuromuscular blockade was measured by an acceleration-responsive transducer (the Accelograph, Biometer International, Odense, Denmark). Responses were defined in terms of percent depression in first-twitch height and train-of-four response, and the dose-response curves were constructed after probit transformation of the responses. The dose-response curves were found to be parallel for both first twitch height and train-of-four responses. The dose-response lines for the enflurane and isoflurane groups were displaced significantly (P less than 0.01) to the left of the line for the fentanyl-N2O group. The calculated doses producing 50% depression of first twitch height were 21.9, 21.2, 18.9, and 17.8 micrograms/kg for the N2O-fentanyl, halothane, isoflurane, and enflurane groups, respectively. Corresponding calculated doses for 50% depression of train-of-four response were significantly smaller (15.5, 14.4, 13.7, 11.9 micrograms/kg, respectively). The enhancing effects of the volatile anesthetics were reflected by significant prolongation of the clinical duration of neuromuscular blockade by pipecuronium. It is concluded that the potency of pipecuronium is enhanced more by enflurane and isoflurane than halothane or fentanyl-N2O anesthesia.

Adult↗
PubMed1992

Myasthenia gravis and pipecuronium--report of two cases.

The use of pipecuronium in two patients with myasthenia gravis undergoing thymectomy is described. Neuromuscular function was monitored throughout using the train-of-four (TOF) mechanical twitch response. The cumulative dose-response to pipecuronium was determined in both patients during nitrous oxide-oxygen-narcotic anaesthesia. Both patients were sensitive to pipecuronium. The ED50 doses of pipecuronium were 11.6 and 11.1 micrograms.kg-1 and the ED95 doses were 35 and 33.3 micrograms.kg-1 in patients #1 and 2 respectively. Edrophonium 1 mg.kg-1 and neostigmine 0.06 mg.kg-1 were administered to patients #1 and 2 respectively for antagonism of residual neuromuscular blockade at 25 per cent spontaneous recovery of first twitch (T1) of the TOF stimulation. As with other non-depolarizing muscle relaxants pipecuronium in reduced dosage and with careful neuromuscular monitoring can be used to provide surgical relaxation safely in patients with controlled myasthenia gravis.

Adult↗
PubMed1991

Neostigmine and edrophonium for reversal of pipecuronium neuromuscular blockade.

Neostigmine 0.06 mg.kg-1 or edrophonium 1 mg.kg-1 were administered to two groups of 15 patients each for antagonism of pipecuronium-induced neuromuscular block at 20% spontaneous recovery of the first twitch (T1) of the train-of-four (TOF) stimulation. The mean onset of action (+/-SEM) of edrophonium (18.1 +/- 2.4 sec) was significantly more rapid (P less than 0.01) than that of neostigmine (47.6 +/- 4 sec), as were the times taken to attain a TOF ratio of 0.25 and 0.5. Nevertheless, the reversal time (time taken from the end of injection of the antagonist until TOF ratio value had reached 0.75) was significantly shorter (P less than 0.01) in the neostigmine than in the edrophonium group (499.3 +/- 62 vs 767 +/- 52 sec respectively). The TOF ratio ten minutes after reversal was greater in the neostigmine group than in the edrophonium group (P less than 0.01), 0.78 +/- 0.02 vs 0.68 +/- 0.02 min respectively. At that time, 33% (5 out of 15) and 80% (12 out of 15) patients failed to be reversed adequately (TOF ratio of 0.75) after neostigmine 0.06 mg.kg-1 and edrophonium 1 mg.kg-1, respectively. Administration of one additional dose (one-third of the initial dose) of the same antagonist resulted in adequate antagonism in the remaining five patients in the neostigmine group and in nine patients in the edrophonium group. Two such doses were required in the remaining three patients in the latter group. The mean total dose of neostigmine and edrophonium employed in this study was 0.067 +/- 0.002 and 1.3 +/- 0.05 mg.kg-1, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Edrophonium priming alters the course of neuromuscular recovery from a pipecuronium neuromuscular blockade.

This study was designed to investigate the effect of divided administration of edrophonium on the course of neuromuscular recovery from a pipecuronium neuromuscular blockade. During thiopentone-nitrous oxide-halothane anaesthesia 48 patients were given pipecuronium 70 micrograms.kg-1. Patients were randomly assigned to one of four groups (n = 12 in each) to receive either edrophonium 1 mg.kg-1 (Groups I and II) or edrophonium 0.75 mg.kg-1 (Groups III and IV). In Groups I and III (single-dose groups), edrophonium was administered as a single bolus dose. In Groups II and IV (divided-dose groups) edrophonium was administered as an initial dose of 0.25 mg.kg-1 followed three minutes later by either 0.75 or 0.50 mg.kg-1 respectively. Reversal was attempted at 20% spontaneous recovery of twitch height. Administration of edrophonium in divided doses (Groups II and IV) accelerated the reversal of the pipecuronium neuromuscular blockade. At ten minutes post-reversal, train-of-four (TOF) ratio recovery reached 0.75 or more in 12 (100%) and in ten (83%) patients in Groups II and IV respectively. Similarly, times to attain a TOF of 0.75 (SEM) were shorter in the divided-dose groups than in the single-dose groups (P less than 0.05), being 354.5 (38.7) and 398.3 (49.1) sec in Groups II and IV vs 705.4 (66.6) and 651.2 (54.3) sec in Groups I and III respectively. Time was counted from the first administration of edrophonium. It is concluded that administration of edrophonium in divided doses produced a faster reversal of residual pipecuronium-induced neuromuscular blockade than single bolus administration. Also, administration in divided doses reduced the requirements of edrophonium needed for reversal of pipecuronium neuromuscular blockade.

Adult↗
PubMed1991

Thiopentone-propofol hypnotic synergism in patients.

The hypnotic effects of thiopentone, propofol and their combination were studied in 120 unpremedicated ASA group I patients. The end-point for induction of anaesthesia was taken as inability to open the eyes to command 60 s after the end of injection. The dose-response curves were determined by probit analysis. Isobolographic and algebraic (fractional) analyses were used to assess quantitatively the combined hypnotic effect of thiopentone and propofol and to define the type of interaction between these two drugs. The interaction between thiopentone and propofol was found to be synergistic.

Adult↗
PubMed1991

Comparative effects of pipecuronium and tubocurarine on plasma concentrations of histamine in humans.

We have examined the effects of a rapid bolus dose of pipecuronium 0.1 mg kg-1 or tubocurarine 0.5 mg kg-1 on plasma histamine concentration, heart rate and arterial pressure in 20 patients (n = 10 in each group). Anaesthesia was induced with thiopentone 6 mg kg-1 i.v. and maintained with 70% nitrous oxide and halothane in oxygen. Neuromuscular blocking drugs were administered 4 min after administration of thiopentone. Venous blood samples were obtained before induction, 1 min after thiopentone and 1, 3 and 5 min after the administration of the neuromuscular blocking drugs. Tubocurarine caused 240% and 210% increases in plasma concentration of histamine at 1 and 3 min, respectively. These changes were significant (P less than 0.05) at 1 min and associated with a decrease in mean arterial pressure and an increase in heart rate. None of the 10 patients receiving pipecuronium had a significant change in plasma concentration of histamine or in haemodynamic variables.

Adult↗
PubMed1991

Ketamine for caudal analgesia in children: comparison with caudal bupivacaine.

Fifty children undergoing inguinal herniotomy were allocated randomly to three groups to receive a caudal injection of either 0.25% bupivacaine 1 ml kg-1 with or without ketamine 0.5 mg kg-1 or ketamine 0.5 mg kg-1 with normal saline 1 ml kg-1. There was no significant difference in quality of pain relief, postoperative behaviour or analgesic requirements between the ketamine group and the two other groups. The bupivacaine-ketamine mixture provided better analgesia than the bupivacaine solution alone. Side effects such as motor weakness or urinary retention were not observed in the ketamine group.

Analgesia, Epidural↗
PubMed1991

Paraphrenia revisited.

Paranoid disorders of late life, commonly known as paraphrenia, are not uncommon. This article reviews the history of the concept, the classification, the possible risk factors implicated in causation and the natural history of the disorder. Evidence suggests that paraphrenia is distinct from schizophrenia and that an organic substrate probably exists in most cases.

Aged↗
PubMed1991

[Paraphrenia in the elderly. Psychopathologic and computer tomography indications of two subtypes].

Psychopathological and cranial computed tomography findings in 48 patients with late paraphrenia were compared with the findings in 40 normal controls. 19 patients with late paraphrenia and first rank symptoms showed significantly less cortical atrophy than 29 patients without first rank symptoms (p less than 0.01). There were no significant differences of ventricular enlargement, cerebellar atrophy, the presence of leukoaraiosis or basal ganglia mineralisation between the late paraphrenic and control groups. In contrast to the controls, cortical atrophy, ventricular enlargement and the presence of leukoaraiosis were not age-related. These results may indicate different origins of late paraphrenia with or without first rank symptoms.

Aged↗