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M Naguib

Publications and source records attributed to M Naguib.

At least 19 recordsLinked to original sources
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↗
PubMed1990

Cardiopulmonary resuscitation skills of medical professionals.

This study examined the theoretical knowledge and practical skills of different medical profession personnel and medical students in Basic Cardiac Life Support (BCLS). Two hundred twenty-four candidates who attended a BCLS course were tested in their theoretical knowledge of BCLS with 15 multiple choice questions (MCQs) as a pre-test. The same questions were included in the post-test but with a different sequence. We also evaluated each candidate during performance of single-rescuer CPR on a recording manikin, using a checklist and the recording strip from the manikin for evaluation of CPR steps and manikin performance respectively. Anesthesiologists and cardiologists demonstrated the best performance in the theoretical knowledge test followed by GPs and paramedics. In contrast, physicians, surgeons, pediatricians and medical students had comparable scores. No candidate performed all CPR steps correctly in the proper sequence. In addition, the manikin performance of all groups was poor. Nevertheless, the course significantly improved the theoretical knowledge (P less than 0.0001) and performance in both CPR steps (P less than 0.0005) and manikin performance (P less than 0.0005). The multivariate discriminant analysis identified that experience and prior CPR training influenced significantly (P less than 0.001) the degree of retention of theoretical knowledge only, but not the actual performance of basic resuscitation. It is concluded that no assumption based on previous clinical knowledge should be made for the expected CPR performance of all doctors, regardless of speciality. Formal training programs in medical schools should be considered. Our data also indicate that training is the only objective way to improve performance of all the candidates including the medical students.

Allied Health Personnel↗
PubMed1989

Atropine-neostigmine mixture: a dose-response study.

The dose-response relationship and the doses of atropine required to prevent neostigmine from lowering heart rates below baseline in 50 per cent (ED50) and 95 percent (ED95) of patients after antagonism of pancuronium-induced neuromuscular blockade were determined in 70 patients with neostigmine-atropine mixtures. Neostigmine 0.04 mg.kg-1 (group A, n = 35) or 0.06 mg.kg-1 (group B, n = 35) was randomly mixed with one of seven doses of atropine (ranging from 0.014 to 0.04 mg.kg-1) in group A and from 0.02 to 0.04 mg.kg-1 in group B), with dose-response curves for atropine being constructed for both groups 5 and 10 min after injection of the mixture. These dose-response curves were found to be parallel in both groups. The calculated ED50 and ED95 values of atropine were similar in both groups. The estimated ED50 doses of atropine in groups A and B at 5 min were 0.031 and 0.033 mg.kg-1 respectively, and at 10 min the ED50 doses were 0.037 and 0.037 mg.kg-1 respectively. The calculated ED95 doses of atropine in groups A and B at 5 min were 0.05 and 0.046 mg.kg-1, and at 10 min the ED95 doses were also similar, being 0.06 and 0.055 mg.kg-1 respectively. Under the conditions employed in this study it would seem that in order to prevent late reductions in heart rates, the appropriate doses of atropine when used with neostigmine should be greater than that commonly used.

Adult↗
PubMed1989

Train-of-four ratio after antagonism of atracurium with edrophonium: influence of different priming doses of edrophonium.

This study was designed to investigate the effect of different priming doses of edrophonium on the relationship between the the recovery of the first twitch of the train-of-four (T1) and train-of-four (TOF) ratio. This relationship was studied after the administration of the full dose of the antagonist in all groups. Edrophonium 1.0 mg.kg-1 was administered either in a single bolus dose (Group I, controls) or in an initial dose of 0.05, 0.1, 0.15 or 0.2 mg.kg-1 followed one minute later by the remainder of the 1.0 mg.kg-1 dose in Groups II to V. Reversal was attempted at the ten per cent spontaneous recovery of twitch height (T1) from atracurium-induced neuromuscular blockade. Of all the groups studied, Group V had a significantly greater recovery in the TOF ratio at any given T1 value. When first twitch tension (T1) had recovered to 100 per cent of the control, it was found for the same tension that the TOF ratio was greater in Group V, being 0.75 compared to 0.63, 0.65, 0.65 and 0.64 in Groups I to IV respectively. The implication is that this differential ability to reverse fade (or prejunctional activity) may be involved in the acceleration of recovery.

Adult↗
PubMed1988

Pharmacokinetic profile of epidural meperidine with and without dextran 70.

To evaluate the effect of dextran 70 on the kinetics of epidural meperidine, 10 female patients anesthetized with nitrous oxide and halothane were studied. Meperidine, 1 mg.kg-1, was administered epidurally in either 10 ml dextran 70 in saline solution (group I) or 10 ml saline solution (group II, control subjects). Plasma concentration of meperidine was determined for 10 hours after its administration with GC. Meperidine plasma concentration-time curves could be best resolved into three exponential terms with a lag time in both groups of patients. The disposition kinetics were described adequately by a three-compartment model. This study demonstrated that apart from a significantly longer lag time and smaller k10 (apparent first-order rate constant for elimination of meperidine from the central compartment), the addition of dextran did not alter significantly the kinetic parameters of epidural meperidine.

Adult↗
PubMed1987

The pattern of train-of-four fade after atracurium: influence of different priming doses.

This study was designed to investigate the effect of three different priming doses of atracurium--0.06, 0.07, and 0.08 mg/kg--followed 3 min later by the remainder of a 0.5 mg/kg dose on the relationship between the depression in the first twitch of the train-of-four (T1) and train-of-four (TOF) fade. This relationship was studied after the administration of the full dose of the relaxant in all groups. Of all the priming doses, 0.08 mg/kg atracurium, when followed 3 min later by 0.42 mg/kg atracurium, had a significantly greater fade in the TOF ratio at any given T1 value. This may indicate significant prejunctional activity. Acceleration of the onset of neuromuscular blockade was, however, evident in all groups that received atracurium in divided doses. The implication is, therefore, that prejunctional activity may not contribute significantly to the acceleration of onset of neuromuscular blockade after administration of atracurium in divided doses, as described in this study.

Atracurium↗