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Biomedical subjects

L H Booij

Publications and source records attributed to L H Booij.

At least 109 records · Page 6Linked to original sources
PubMed1985

Propofol ('Diprivan') emulsion for total intravenous anaesthesia.

Propofol as an hypnotic in combination with fentanyl and vecuronium was used for total intravenous anaesthesia in 30 healthy unpremedicated patients undergoing elective surgery scheduled to last no longer than 1 h. Induction with propofol 2 mg/kg and fentanyl 1.875 micrograms/kg resulted in cessation of counting after 39 s and the loss of the eyelash reflex after 57 s. Mean recovery times, measured from the end of the infusion of propofol (9 mg/kg/h) and fentanyl (7.5 micrograms/kg/h) until eyes opened on command and questions answered correctly were 10.5 and 11.5 min, respectively. Trieger test, performed 3 h postoperatively, showed no difference in comparison with the preoperative score. During longer procedures there was evidence of accumulation in that propofol utilization rate decreased as the duration of anaesthesia increased. The results obtained are similar to those described with the previous Cremophor formulation although greater variability in induction and recovery times was noted with the emulsion formulation.

Adult↗
PubMed1984

In vitro interaction of diazepam and oxazepam with pancuronium and suxamethonium.

In vitro studies using the rat phrenic nerve-hemidiaphragm preparation were performed to investigate the effects of diazepam and three of its metabolites on indirectly evoked twitch tension. Diazepam, desmethyldiazepam and temazepam alone caused an increase in twitch tension in lower concentrations, followed by complete depression in higher concentrations. Oxazepam did not cause an initial increase in twitch tension, but showed an immediate and dose-dependent depression. Cumulative concentration-response curves for pancuronium and suxamethonium in the presence of different concentrations of diazepam or oxazepam showed that small concentrations of diazepam, which did not change twitch tension alone, caused antagonism of the action of pancuronium, but not of suxamethonium. With oxazepam no such antagonism was observed. In liminal and supraliminal concentrations, both diazepam and oxazepam potentiated the action of pancuronium and suxamethonium. Possible implications for in vivo interactions are discussed.

Animals↗
PubMed1984

Effect of some benzodiazepines on peripheral neuromuscular function in the rat in-vitro hemidiaphragm preparation.

The effect of equimolar cumulative concentrations of 11 different benzodiazepines on the indirectly evoked twitch contraction was investigated in the rat in-vitro phrenic nerve-hemidiaphragm preparation. Depending on the pattern of the concentration-response curves two groups of benzodiazepines can be distinguished: (i) a first group with a biphasic action, e.g. potentiation of twitch tension in low concentrations and depression of twitch tension in high concentrations, and (ii) a second group with primary depression of twitch tension with increasing concentrations. All of the tested compounds ultimately caused a 100% depression of twitch tension at concentrations ranging from 0.175 to 0.35 mmol litre-1. Although this peripheral effect of benzodiazepines on neuromuscular function is not the main site of action of these compounds, there are enough arguments to state that it is not a simple toxic effect. There is some evidence from this study that the peripheral component of the benzodiazepine effect on muscle relaxation may involve a multi- rather than one single receptor system.

Animals↗
PubMed1984

[Double-blind testing of alfentanyl and fentanyl in total intravenous anesthesia].

Fentanyl or alfentanil (at a dose ten times that of fentanyl) was administered to fifty healthy patients undergoing elective surgery. They were given in a double-blind manner for analgesia in a total intravenous anaesthesia technique to see if differences existed in their respiratory depressant, analgesic or sedative effects. They were combined in the same syringe with etomidate and given by intravenous bolus injection followed by a continuous intravenous infusion. Analgesia was generally adequate for the operations in this study. Respiratory depression (respiratory rate less than ten) lasted about ten minutes after drug administration, ceased in all patients. The return of respiratory rate, consciousness, and psychomotor performance to control was similar in the groups receiving fentanyl or alfentanil. This study showed that alfentanil and fentanyl have equivalent potency and duration of action when used in a ten to one ratio. Furthermore, the technique provided good operating conditions but there was a high incidence of postoperative drowsiness, nausea and vomiting.

Adjuvants, Anesthesia↗
PubMed1984

Air embolism due to the Mayfield skull clamp.

During posterior craniotomy of a 77 years old man in the sitting position air embolism was monitored and reoccurred not withstanding proper measures. Only at the end of the operation the source was discovered: when the head was removed from the Mayfield skull clamp the embolism reoccurred once more. All this not withstanding the meticulous treatment of the three points of the head holder with antibacterial ointment, in the beginning.

Aged↗
PubMed1984

[Monitoring neuromuscular function in the operating theater].

The advantages of monitoring neuromuscular blockade during anaesthesia and intensive care by electromyography or mechanomyography are reviewed. Correlations between clinical symptoms, monitoring parameters and percentage of receptor occupation are established. Single twitch, train of four and tetanic stimulation of motor nerves are described in detail and their relative indications discussed. It is pointed out, that neuromuscular transmission can be considered to be unimpaired, if single twitch responses equal 100% of preblock values and train of four ratios achieve 0.7. Especially under conditions of hypothermia, acid-base disturbances or side effects of drugs other than muscle relaxants monitoring of neuromuscular transmission is superior to simple clinical judgment.

Anesthesia↗
PubMed1983

Pharmacokinetics of the infusion of alfentanil in man.

The pharmacokinetics of alfentanil under the conditions of an empirically derived 1-h continuous infusion of 3 micrograms kg-1 min-1, with a bolus of 80 micrograms kg-1, both i.v., were determined in five patients. The distribution half-life (mean +/- SD) (7.4 +/- 3.1 min), elimination half-life (86.7 +/- 15.8 min), apparent volume of distribution, Varea (0.44 +/- 0.15 litre kg-1) and elimination clearance (3.33 +/- 0.75 ml kg-1 min-1) were similar to those previously reported for a single bolus of alfentanil. These values for apparent volume of distribution and clearance can be used to calculate correct bolus and infusion doses to maintain any desired steady state plasma concentration using standard formulae: for example, to maintain a steady state plasma concentration of 400 ng ml-1, a bolus dose of 176 micrograms kg-1 and an infusion of 1.3 micrograms kg-1 min1 would be required.

Adult↗
PubMed1983

Clinical comparison of atracurium and vecuronium (Org NC 45).

The potency, histamine releasing ability, cardiovascular effects, and pharmacodynamics of vecuronium and atracurium were investigated in 64 healthy patients following administration i.v. Cumulative dose-response curves showed vecuronium to be 4.4 times as potent as atracurium. Using the calculated ED90 of each drug (43 micrograms kg-1 for vecuronium and 188 micrograms kg-1 for atracurium), vecuronium had a significantly more rapid onset time and shorter duration of action than atracurium. When three times the ED90 doses were used (129 micrograms kg-1 for vecuronium and 564 micrograms kg-1 for atracurium), no statistically significant differences in the pharmacodynamics were seen between the two drugs, although vecuronium tended to be shorter-acting. There was no clinical evidence of histamine release during the study. No clinically significant changes in arterial pressure or heart rate were seen after the injection of either drug, although vecuronium caused a statistically significant decrease in heart rate (approximately 5%) at 5 and 10 min after administration. Both drugs would appear to have certain advantages over existing non-depolarizing neuromuscular blocking drugs.

Adolescent↗
PubMed1983

Interactions of diisopropyl phenol (ICI 35868) with suxamethonium, vecuronium and pancuronium in vitro.

In vitro studies were performed using the rat phrenic nerve-hemidiaphragm preparation to investigate possible interactions between diisopropyl phenol and its solvent, cremophor, with three neuromuscular blocking drugs. Cumulative concentration curves were constructed for the neuromuscular blockers and linear regression analyses performed. Differences in the calculated effective concentration to produce a 50% decrease in twitch height (EC50) and slope showed that diisopropyl phenol potentiated the action of suxamethonium, vecuronium (Org NC 45) and pancuronium. Cremophor potentiated the action of suxamethonium but antagonized the action of the non-depolarizing neuromuscular blockers. The possible mechanisms of action are discussed.

Anesthetics↗
PubMed1983

Some effects of diisopropyl phenol (ICI 35 868) on the pharmacodynamics of atracurium and vecuronium in anaesthetized man.

The effects of a bolus injection of diisopropyl phenol 2 mg kg-1 i.v. and an infusion (150 micrograms kg-1 min-1 for 30 min and 75 micrograms kg-1 min-1 thereafter) on the pharmacodynamics and dose-response curves of atracurium and vecuronium were studied in 52 healthy (ASA I or II) patients. Under anaesthesia with diisopropyl phenol, the cumulative dose-response curves of both myoneural blocking drugs were shifted to the left when compared with previously reported results. However, there was no clinically significant change in the pharmacodynamics of either drug after the bolus injection of the blocking drug. Diisopropyl phenol 2 mg kg-1 i.v. administered during steady-state infusions of vecuronium and atracurium increased the depth of the constant neuromuscular blockade. When diisopropyl phenol alone was given to four patients there was no change in the twitch height. These results show that diisopropyl phenol, given according to the regimen in this study, potentiates both of the neuromuscular blockers studied but does not prolong the duration of action of either drug. During the infusion of diisopropyl phenol, vecuronium was found to be five times more potent, to have a more rapid onset time, and to be shorter acting than an equipotent dose of atracurium.

Adolescent↗
PubMed1983

Disoprofol (ICI 35868) for total intravenous anaesthesia.

The purpose of this study was to evaluate disoprofol as the hypnotic for total intravenous anaesthesia. Sixty women undergoing minor gynaecological surgery participated and were randomly assigned to four groups (N = 15 in each group). Disoprofol, 2 mg/kg was given i.v. to induce anaesthesia after a bolus injection of either fentanyl 1.875 micrograms/kg or alfentanil 18.75 micrograms/kg. Vecuronium, 0.06 mg/kg, was given for muscle relaxation when indicated. One-half of the patients received acute premedication with midazolam, 5 mg i.v. Anaesthesia was maintained with a continuous infusion of disoprofol 150 micrograms/kg/min and either fentanyl 0.125 micrograms/kg/min or alfentanil 1.25 micrograms/kg/min. These drug combinations were compatible and produced good operating conditions. Awakening time was significantly shorter for women who received no premedication and was not affected by the narcotic used. Respiration returned more quickly when fentanyl was the narcotic given and was not affected by premedication. Both hypotension and bradycardia were seen in some patients, but other side effects were infrequent. This total intravenous anaesthesia technique was very well accepted by the patients and the nurses who cared for them in the postoperative period.

Adult↗
PubMed1983

Intradermal histamine release by 3 muscle relaxants.

The induration and redness caused by intradermal injections of equipotent doses of atracurium, vecuronium and d-tubocurarine were measured in six healthy, male volunteers. Atracurium and d-tubocurarine were almost indistinguishable in their reactions. Vecuronium caused a significantly smaller response than both atracurium and d-tubocurarine. We therefore suggest that of these three drugs, vecuronium may cause the least histamine release and is, perhaps, the drug of choice in patients with a history of asthma or allergy.

Adult↗
PubMed1983

[Comparative study of thiopental and midazolam for induction of anesthesia].

In 40 female ASA class I-II patients, scheduled for laparoscopy, midazolam 0.2 mg kg-1 i.v. was compared with thiopentone 5 mg kg-1 i.v. for induction of anaesthesia after parenteral premedication. Loss of the eyelash reflex occurred significantly earlier (p less than 0.005) in the thiopentone group (23.3 s) than in the midazolam group (37.5 s). During orotracheal intubation a more stable cardiovascular course was found with midazolam than with thiopentone. Awakening was markedly slower with midazolam than with thiopentone. Anterograde amnesia of more than 60 minutes after induction of anaesthesia occurred in 50% of midazolam patients compared with 10% in the thiopentone group. No significant differences in side effects could be found. Midazolam 0.2 mg kg-1 was sufficient to induce anaesthesia reliably after premedication with droperidol and fentanyl shortly before induction.

Adult↗