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Biomedical subjects

L H Booij

Publications and source records attributed to L H Booij.

At least 91 records · Page 5Linked to original sources
PubMed1987

Influence of ketanserin (serotonin antagonist) on bladder and urethral function.

As it is known that serotonin or 5-hydroxytryptamine can enhance bladder activity, we studied urodynamically the effect of ketanserin, a serotonin antagonist, in 17 patients, in the hope that this drug might be useful in treating unstable bladders. However, a relaxant effect on bladder contractility could not be demonstrated. On the contrary, a significant decrease of the urethral pressure was observed, suggesting that ketanserin might still have a possible role in promotion of bladder emptying. The relaxant effect on the urethra suggests some alpha-sympathicolytic activity of ketanserin.

Adolescent↗
PubMed1987

Propofol emulsion for induction and maintenance of anaesthesia. A combined technique of general and regional anaesthesia.

To provide general anaesthesia with endotracheal intubation during regional blockades, three dose regimens of propofol emulsion were studied: induction 2 mg kg-1, infusion rate 9 mg kg-1 h-1 (Group 1); induction 2.5 mg kg-1, infusion rate 12 mg kg-1 h-1 (Group 2); induction 2.5 mg kg-1, infusion rate 9 mg kg-1 (Group 3). Each group comprised 10 healthy (ASA class 1 or 2) unpremedicated patients. The induction times measured from the start of injection until counting ceased (+/- 50 s) and until eye-lash reflex disappeared (+/- 80 s) showed no statistical differences between groups. In five patients in Group 1 and one patient in each of Groups 2 and 3 the induction dose was too low for intubation. Pain on injection was seen in 13 cases (mild 6, moderate 6 and severe 1). Cough accompanied by hypersalivation was the most important side-effect. Recovery times varied widely and showed no statistical differences. Answering simple questions was possible after 14 min in Group 1, 23 min in Group 2 and 19 min in Group 3. Apart from a short period of euphoria, recovery was uneventful. There was no tendency to fall asleep again. None of the combinations of induction doses and infusion rates provided good anaesthesia conditions for an acceptable number of patients.

Adult↗
PubMed1987

The capnograph, a reliable non-invasive monitor for the detection of pulmonary embolism of various origin.

The wash-out curve in the capnogram is known to be a sign of pulmonary air embolism. This characteristic pattern is also seen in the case of pulmonary embolism of other nature. Capnographic recordings were studied retrospectively and 22 wash-out curves were found. The quantitative change in end-tidal carbon dioxide concentration was compared with the change in other, circulatory parameters known to change in the case of pulmonary air embolism. There proved to be a quantitative correlation between the decrease in end-tidal carbon dioxide concentration and the change in pulmonary artery pressure, central venous pressure and mean arterial pressure. The capnograph showed to be a reliable monitor for the detection of pulmonary embolism of various origin just like pulmonary artery pressure monitoring is. In cases with concomitant Doppler ultrasound detection, the capnograph showed to be a more reliable monitor for the detection of pulmonary air embolism as is the Doppler ultrasound device.

Blood Pressure↗
PubMed1987

Pulmonary edema following air embolism.

Venous air embolism is a major hazard during surgical procedures in the sitting position and is known to cause acute pulmonary edema in animal experiments (6, 7, 17). In man some cases of pulmonary edema immediately following air embolism have been described (10, 15, 16). In this case report we present a patient that developed pulmonary edema which became apparent several hours after the occurrence of air embolism.

Aged↗
PubMed1986

Infusion of vecuronium controlled by a closed-loop system.

Closed-loop control of neuromuscular blockade, using a semi-continuous infusion of vecuronium, is described. In 28 patients, the average neuromuscular transmission was between 13 and 17% of control. Requirements for vecuronium averaged 1.1 micrograms kg-1 min-1 (0.8-1.5 micrograms kg-1 min-1), being in the same range as for repeated bolus injections. No side effects were observed. After the infusion was stopped recovery was rapid. Only three patients required induced reversal of blockade.

Feasibility Studies↗
PubMed1986

Benzodiazepines and neuromuscular blocking drugs in patients.

The interaction between four benzodiazepines (diazepam, lorazepam, lormetazepam and midazolam) and two nondepolarizing neuromuscular blocking drugs (vecuronium and atracurium) was investigated in 113 patients during general anaesthesia. Neuromuscular function was monitored by recording the mechanical twitch tension of the adductor pollicis muscle of the thumb in response to ulnar nerve stimulation with single supramaximal stimuli of 0.2 ms at 0.1 Hz. In the first group of patients a benzodiazepine (diazepam 20 mg, lorazepam 5 mg, lormetazepam 2 mg or midazolam 15 mg), was injected i.v. 15 min before a single bolus of vecuronium 45 micrograms kg-1. In the second group of patients suxamethonium 1 mg kg-1 was given for endotracheal intubation, and 30 min later the patients received atracurium 200 micrograms kg-1. Fifteen min before injection of atracurium one of the same benzodiazepines as in the first group was injected i.v. Comparisons were made with control patients receiving thiopentone. Neither benzodiazepine caused significant potentiation of neuromuscular blocking agents in comparison with control. With midazolam, however, the duration to 25% and to 75% recovery of the twitch height after vecuronium was significantly longer than with diazepam. The time to 25% recovery of the twitch height after atracurium was significantly longer in patients receiving midazolam than in those receiving diazepam. The recovery index was not influenced by the four benzodiazepines.

Anesthesia↗
PubMed1986

The selection of anesthesia induction agents with respect to intubation induced bradycardia.

During induction of anesthesia and intubation dangerously low heart rates sometimes occur. In this study the short term influence of various commonly used anesthetics on heart rate was investigated, before, during and immediately after intubation. Various combinations of the drugs Fentanyl, nicomorphine, etomidate, thiopentone, succinyldicholine and vecuronium were studied in patients of ASA class I and II. The drugs nicomorphine, thiopentone and vecuronium did induce only minimal and short term heart rate changes. They are therefore safer in this respect and should probably be preferred for anesthesia induction of patients with known small cardiovascular safety margin.

Adult↗
PubMed1985

Interaction of midazolam with two non-depolarizing neuromuscular blocking drugs in the rat in vivo sciatic nerve-tibialis anterior muscle preparation.

Studies of the possible interactions between the water-soluble benzodiazepine, midazolam, and two non-depolarizing neuromuscular blocking drugs, vecuronium and tubocurarine, were performed in the rat in vivo sciatic nerve-tibialis anterior muscle preparation. Midazolam 0.5 and 5 mg kg-1 caused 17% and 34% depression of the twitch height, respectively, once a steady-state blockade of the twitch height had been induced by vecuronium. The potentiation of the tubocurarine steady state blockade by midazolam 5 mg kg-1 was quantitatively equal to that of vecuronium, but was slower in onset. The buffer solvent of midazolam 5 mg kg-1 did not change the steady-state blockade of vecuronium. Midazolam 5 mg kg-1 caused a shift to the left of the cumulative dose-response curves of vecuronium.

Animals↗
PubMed1985

The in vitro effects of benzodiazepines on the rat diaphragm. Structure-activity relationships.

The effect of three different subgroups of benzodiazepines on the indirectly evoked twitch tension was investigated in the in vitro rat phrenic nerve - hemidiaphragm preparation. Two effects were observed: an initial increase in twitch tension at lower concentrations with some benzodiazepines, and a concentration-dependent depression at higher concentrations with all benzodiazepines. Significant differences for these effects were observed among the three subgroups of benzodiazepines and additionally within the subgroup of the 1,4-benzodiazepine-2-ketones. Structural requirements for both effects were different. For the increase of twitch tension a --CH3 substitution at R1 and a --F substitution at R2' were beneficial. For the twitch depression an --OH substitution at R3 and a --C1 substitution at R2' were optimal. An interaction between substituents at different substitution sites occurred. The potency of twitch depression showed a good correlation with literature reports of pKa values and a poor-to-inverse correlation with lipophilicity indices. A benzodiazepines antagonist, Ro 15-1788, caused no change in twitch tension in the concentration range of the investigated benzodiazepines nor did it prevent the twitch depression caused by benzodiazepines.

Animals↗
PubMed1985

Interaction of some benzodiazepines and their solvents with vecuronium in the in vivo rat sciatic nerve-tibialis anterior muscle preparation.

Interaction studies between different injectable benzodiazepines and vecuronium, a non-depolarizing neuromuscular blocking drug, were performed in the rat in vivo sciatic nerve-tibialis anterior muscle preparation. The investigated doses were aimed to be "sedative" in the rat. A significant antagonism of a steady state depression of the twitch height induced by vecuronium was observed during approximately 10 min after i.v. injection of those benzodiazepines containing organic solvents in their formulations (diazepam, desmethyldiazepam, oxazepam, temazepam, lorazepam and lormetazepam). This antagonism is mainly due to propylene glycol, the main organic solvent for the poorly water-soluble benzodiazepines. After the initial antagonism, a potentiation of the vecuronium-induced depression occurred with some of these benzodiazepines (diazepam, desmethyldiazepam, temazepam and lormetazepam). Two water-soluble benzodiazepines, midazolam and flurazepam, caused a significant potentiation of the vecuronium-induced block. Important side-effects (blood pressure drop, convulsions, hematuria) were observed with the amount of propylene glycol present in the investigated formulation of lormetazepam.

Animals↗
PubMed1985

Lack of effects of emulsified propofol ('Diprivan') on vecuronium pharmacodynamics--preliminary results in man.

The possible interaction between vecuronium and propofol or thiopentone has been investigated. Cumulative dose response curves for vecuronium and the pharmacodynamic variables measured were similar with both anaesthetic agents. Patients were intubated following the topical application of lignocaine to the larynx and before the administration of vecuronium. A greater degree of relaxation of the vocal cords was noted in patients anaesthetized with propofol.

Adolescent↗
PubMed1985

Pharmacodynamics of vecuronium, atracurium, tubocurarine and their combinations in the rat in vivo.

In the in vivo rat sciatic nerve tibialis muscle preparation the potency and pharmacodynamics of vecuronium, atracurium, pancuronium, tubocurarine and their combinations were studied. Considering the potency only, there was no beneficial difference between the pure compounds and their combinations. As both vecuronium and atracurium are almost free from side-effects individually, a combination of the two relaxants brings no advantage.

Animals↗