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Biomedical subjects

L H Booij

Publications and source records attributed to L H Booij.

At least 55 records · Page 3Linked to original sources
PubMed1994

A comparison of rocuronium and vecuronium: the pharmacodynamic, cardiovascular and intra-ocular effects.

The aim of this study was to compare, in 30 patients, the pharmacodynamics of equipotent intubating doses of rocuronium and vecuronium and to compare their effects on heart rate, arterial pressure and intra-ocular pressure under steady state propofol anaesthesia. Baseline readings of heart rate and arterial pressure, using a Dinamap, and intra-ocular pressure, using a Tonopen, were made after induction of anaesthesia. The effects of the administration of the relaxants on these parameters were measured, recorded and compared. Rocuronium had a faster onset time than vecuronium, but had a similar duration of action. Vecuronium had no significant cardiovascular effects. Rocuronium caused a rise in mean arterial pressure (10-15%) and a slight rise in heart rate (5-10%). Both vecuronium and rocuronium caused similar falls in intra-ocular pressure. With its rapid onset time and lack of intra-ocular pressure effects, rocuronium is perhaps the relaxant of choice in patients with penetrating eye injuries requiring emergency endotracheal anaesthesia where a longer-acting relaxant is not contraindicated.

Adolescent↗
PubMed1993

The predictive performance of a system model for enflurane closed-circuit inhalational anesthesia.

BACKGROUND: Previously, the authors described a system model for closed-circuit inhalational anesthesia, and demonstrated close agreement between end-tidal isoflurane concentrations measured in their clinical study and those predicted by the model. The predictive performance of their model has not, however, been tested for anesthetics featuring nonpulmonary elimination (NPE). METHODS: The authors quantified the predictive performance of two versions (A and C) of the model in 50 patients by comparing the predicted and the measured alveolar concentration-time profiles after bolus injections of liquid enflurane into the expiratory limb of the closed system. Version A did not incorporate NPE, but version C emulated NPE by adopting the irreversible loss of a fraction of the enflurane present in the arterial hepatic blood flow (0.131, derived from a mass balance study performed by others). For each concentration measured by mass spectrometry, the authors used computer simulations of version A and C to calculate a predicted concentration for both versions. For each patient, the authors calculated the bias (indicating systematic over- or underprediction) and the scatter of the prediction errors (indicating typical error size). RESULTS: The authors administered a total of 379 ml of liquid enflurane via 466 injections. A total of 18,432 alveolar concentrations (one per 10-s period; average concentration = 0.96 vol%) were measured. The bias and the scatter, both given as mean (and SD), were 10.0 (13.1)% and 11.8 (3.9)% for version A and -0.8 (11.4)% and 11.4 (2.8)% for C. The bias for version C was closer to zero; the scatters were similar. CONCLUSIONS: Version C incorporating NPE performs better than version A. The accuracy that was obtained should encourage the use of version C for clinical, teaching, research, economic, and ecologic purposes.

Adult↗
PubMed1993

Pharmacokinetics of intravenously administered nicomorphine and its metabolites in man.

Intravenous doses of 30, 20 and 10 mg nicomorphine (Vilan) are extremely quickly metabolized into the metabolites 6-nicotinoylmorphine and morphine. The half-lives of elimination are respectively 3 min for nicomorphine, 3 and 15 min for 6-nicotinoylmorphine, and 135-190 min for morphine. The kinetics of the 30 and 20 mg dose are comparable, the 10 mg dose shows patient dependent variations in metabolism. The AUC of the parent drug and its metabolites is linearly related to the dose.

Adult↗
PubMed1992

Coronary artery bypass grafting using two different anesthetic techniques: Part I: Hemodynamic results.

Hemodynamic changes were studied during two different anesthetic techniques in 54 patients undergoing coronary artery bypass grafting (CABG). All patients had normal to moderately impaired left ventricular function and were randomly assigned to two groups. In 27 patients, high thoracic epidural analgesia (TEA) with bupivacaine 0.375% plus sufentanil 1:200,000 (ie, 5 micrograms/mL) was used in combination with general anesthesia with midazolam/N2O; in the other 27 patients, general anesthesia (GA) with midazolam and sufentanil was used. After induction of epidural analgesia, heart rate and mean arterial pressure (MAP) decreased. Changes in cardiac index, systemic vascular resistance, and pulmonary capillary wedge pressure were not observed, whereas the stroke volume index increased significantly. After induction of intravenous anesthesia MAP decreased (20%) in both groups. During the pre-bypass period, metaraminol was used in 7 of 27 patients in the GA group and in 5 of 27 patients in the TEA group to treat hypotension. Inotopic drugs were used in 5 patients in the GA group and in none in the TEA group to treat a low CO. Ten GA patients and 4 TEA patients developed hypertension after sternal spread and the GA patients required more nitroprusside. Four GA patients developed electrocardiographic evidence of prebypass ischemia and, therefore, more nitroglycerin was needed for treating myocardial ischemia. More sodium nitroprusside was needed in the GA group during cardiopulmonary bypass (CPB) and the post-bypass period to treat hypertension with a high SVR. In conclusion, hemodynamic stability was more pronounced in the TEA than the GA group before and after CPB.

Aged↗
PubMed1992

Coronary artery bypass grafting using two different anesthetic techniques: Part 2: Postoperative outcome.

The aim of the present investigation was to study the effects of intraoperative and postoperative epidural pain management during and after coronary artery bypass grafting (CABG) on the recovery time, postoperative pulmonary and cardiac parameters, visual analog scale (VAS) scores, and sedation scores (SS) compared with patients anesthetized with general anesthesia (GA) whose postoperative pain was relieved with intermittent intravenous (IV) administration of nicomorphine. Fifty-four patients were studied postoperatively after uncomplicated CABG. In the thoracic epidural analgesia (TEA) group (n = 27), intraoperative analgesia was based on high TEA in combination with GA. In the GA group (n = 27), IV anesthesia with high-dose sufentanil and midazolam was used. Postoperative pain management in the GA group consisted of intermittent IV administration of nicomorphine, 0.1 mg/kg every 6 hours, whereas for the TEA group continuous high TEA with 0.125% bupivacaine plus sufentanil, 1:1,000,000 (0.05 mL/cm body length/hr) was used. Patients in the TEA group awakened earlier (148 [34] minutes vs 335 [51] minutes), resumed spontaneous respiration earlier (326 [79] minutes vs 982 [52] minutes), and were extubated earlier (463 [79] minutes vs 1140 [58] minutes). VAS score, SS, and postoperative PaO2 were significantly (P less than or equal to 0.01) better in the TEA group. The incidence of tachycardia (15 vs 2 patients) and postoperative myocardial ischemia (12 vs 4 patients) was higher in the GA group. It is concluded that intraoperative and postoperative pain treatment with epidurally administered bupivacaine plus sufentanil improved the recovery time, as well as pulmonary and cardiac outcome after CABG, when compared with IV postoperative pain treatment after intraoperative GA with sufentanil and midazolam.

Analgesia, Epidural↗
PubMed1992

Coronary artery bypass grafting using two different anesthetic techniques: Part 3: Adrenergic responses.

Twenty patients were studied during and after coronary artery bypass grafting (CABG). The patients were randomly assigned to two groups. In 10 patients, intraoperative general anesthesia (GA) was based on a combination of intravenous (IV) sufentanil and midazolam. In 10 other patients, thoracic epidural analgesia (TEA) with 0.375% bupivacaine plus sufentanil, 1:200,000 (5 micrograms/mL), and intraoperative GA with midazolam/N2O were used. During the prebypass period, lower heart rates (HR), less variability in mean arterial pressure (MAP), and systemic vascular resistance (SVR) was accompanied by less variability in plasma norepinephrine (NE) concentrations in the TEA group. Although no differences were observed between the groups in perfusion pressure and the amount of vasoactive drugs used during the bypass period, variability in SVR was less in the TEA group. This was accompanied by less increase in NE and less variability in epinephrine (E) plasma concentrations. However, cortisol (Co) release was higher during this period in the TEA group. Weaning from bypass was accompanied by higher MAP and SVR in the TEA group at a lower HR, whereas no differences were observed in the E, NE, and Co plasma concentrations between the groups. During the first and second postoperative days, better pain relief and lower E and Co plasma concentrations were found in the TEA group. It can be concluded that better hemodynamic stability during the prebypass and bypass periods was accompanied by less E and NE release during these periods. Co release in the TEA group was higher during the bypass period. Weaning from bypass was characterized by better hemodynamics in the TEA group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Factors affecting magnitude and time course of neuromuscular block produced by suxamethonium.

This study was designed to identify factors that significantly alter the magnitude and duration of suxamethonium-induced neuromuscular block in patients with an apparently normal genotype for pseudocholinesterase. One hundred and fifty-six adults (ages 18-65 yr) were allocated to 13 subgroups. Patients in each subgroup received suxamethonium 50-2000 micrograms kg-1. The mechanographic response of the adductor pollicis brevis muscle to ulnar nerve stimulation was recorded. The ED50 was found to be 167 micrograms kg-1, ED90 was 316 micrograms kg-1 and ED95 was 392 micrograms kg-1. The duration of action (delta t) was in agreement with earlier published results. The magnitude of block was dose-related and decreased with increasing onset time (ton) and pseudocholinesterase activity (PChA). Neither age nor gender affected the degree of suxamethonium-induced block. Delta t was dose-related, decreased with increasing PChA, and was shorter for women. Age and ton had no effect on delta t.

Adolescent↗
PubMed1991

Pharmacokinetics of nicomorphine and its metabolites in man after epidural administration.

In ten patients who received an epidural injection of 15 mg of nicomorphine, the compound was relatively slowly released from the epidural space and was found in plasma for approximately 1.5 h. Nicomorphine is relatively slowly metabolized into 6-nicotinoylmorphine and morphine. The rate of release is patient-dependent. The relative AUC values are 15.3% for nicomorphine, 23.9% for 6-nicotinoylmorphine and 60.8% for morphine. The mean clinical effect lasts for 18.2 +/- 10.1 h.

Adolescent↗
PubMed1991

Pharmacokinetics of intramuscular nicomorphine and its metabolites in man.

After i.m. injection nicomorphine is relatively slowly absorbed from the muscular depot and is found in the serum for approximately 1 h. The rate of absorption differs between patients and governs the overall pharmacokinetic profile of the compound. The relative AUCs were nicomorphine 18%, 6-nicotinoylmorphine 17%, and morphine 65%. Nicomorphine and 6-nicotinoylmorphine have significantly higher AUCs after i.m. injection than after i.v. injection, while the AUC of morphine and the total AUC show no difference between the two modes of administration.

Adult↗
PubMed1991

A system model for closed-circuit inhalation anesthesia. II. Clinical validation.

Recently, we described a basic model and its more elaborate variants to predict the uptake and distribution of inhalational anesthetics during closed-circuit anesthesia. As an initial clinical validation of the linear, continuous, 14-compartment basic model, the current study examined its predictive performance in 50 patients by comparing quantitatively the predicted and the measured alveolar concentration-time profiles after bolus injections of liquid isoflurane into the closed system during mechanical ventilation. The two versions of the model studied differed in the size of their peripheral shunt, as 0% (version A) and 16% (version B) of the cardiac output. A total of 15,744 alveolar concentrations of isoflurane (one per 10s period) were measured by mass spectrometry. For each measured concentration we used computer simulations of version A and version B to calculate a predicted concentration for both versions. For each patient we calculated the bias (indicating over- or underprediction) and the scatter of the prediction errors (indicating the typical error size). The bias and the scatter of the prediction errors, both given as mean (and standard deviation), were 2.25 (13.59) and 12.51 (5.84)% for version A and 12.00 (14.97) and 14.12 (6.54)% for B. Version A performed better than B: both the bias (P = 0.008) and the scatter (P less than 0.0001) were closer to zero for A. Logistic regression analysis showed for version A that scatter, but not bias, increased with age (P = 0.002). Gender, body mass index (weight x height-2), and number of injections per hour did not influence scatter or bias.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

A system model for closed-circuit inhalation anesthesia. I. Computer study.

Developing a custom computer program to simulate the uptake, distribution, and elimination of inhalational anesthetics allows the anesthesiologist to address specific problems, but extensive skills are required to translate the involved processes first into a set of mathematical equations and then into a satisfactory computer program. The first step is often facilitated by solutions offered in the literature. The second step demands computer proficiency that is often not available, but this problem can be obviated by means of a special-purpose simulation language (SPSL). We therefore constructed a model for closed-circuit inhalation anesthesia with the aid of the block-structured SPSL TUTSIM. Noticeable differences with previous models are that the linear, 14-compartment basic model does not assume a constant alveolar concentration and mimics circulation times through the use of blood pools. Advanced features of the SPSL were used to develop variants of the basic model to simulate feedback-controlled isoflurane administration, nitrous oxide uptake, and the impact of a nonlinearity by incorporating the effect of enflurane on cardiac output. Two variants were concatenated to form a multiple model showing the concentration and second-gas effects. The model was capable of reproducing the anesthetic uptake from previous experimental studies for nitrous oxide. After its validation for other anesthetic agents, the model can be used for clinical, teaching, and research purposes. The SPSL freed the authors from the problems associated with computer programming and allowed them to concentrate on the structure of the model.

Anesthesia, Closed-Circuit↗
PubMed1991

The neuromuscular blocking effect of Org 9426. A new intermediately-acting steroidal non-depolarising muscle relaxant in man.

Org 9426, a new steroidal non-depolarising muscle relaxant, which is stable in solution, was studied in 30 anaesthetised (thiopentone, fentanyl, nitrous oxide) male patients, ASA 1 or 2. A dose-response curve for Org 9426 was constructed and the ED90, mean (SD), was found to be 0.36 (0.031) mg/kg. The onset of action was 3.8 (1.8) minutes, the clinical duration 17.4 (3.2) minutes, the total duration of action 31.9 (6.2) minutes and the recovery time 9.96 (3.2) minutes. No signs of histamine release or cardiovascular effects were observed. Org 9426 thus has a faster onset of action than vecuronium bromide or atracurium dibesylate.

Adult↗
PubMed1991

Thoracic epidural analgesia in a patient with bilateral phaeochromocytoma undergoing coronary artery bypass grafting.

A patient suffering from phaeochromocytoma and coronary artery stenoses needed coronary artery bypass grafting before adrenalectomy. High thoracic epidural analgesia (T1-T2) with bupivacaine and sufentanil in combination with general anaesthesia was used. Plasma adrenaline and noradrenaline concentrations decreased during the period before bypass grafting compared to the baseline value and no important haemodynamic changes were seen during this period. Thoracic epidural analgesia failed to suppress the release of catecholamine during the bypass period. After the operation, the plasma catecholamine concentrations returned to the baseline value. Excellent analgesia (visual analogue scale = 1-2) was achieved with a postoperative epidural, but the plasma catecholamine concentration increased considerably.

Adrenal Gland Neoplasms↗
PubMed1991

The effects of a 16-N-homopiperidino analogue of vecuronium on neuromuscular transmission in anaesthetized cats, pigs, dogs and monkeys, and in isolated preparations.

Org 9991, a 16-N-homopiperidinium substituted vecuronium analogue, has been tested for neuromuscular blocking activity in anaesthetized cats, pigs, dogs and monkeys, and in isolated nerve-muscle preparations. Org 9991 exhibited non-depolarizing neuromuscular blocking activity of the competitive type, being reversible by neostigmine and showing no endplate channel blocking action in isolated preparations. In cats, 50% vagal block was observed at doses of Org 9991 approximately 10 times those producing 50% neuromuscular block; no ganglion block was seen at these doses. Effects on blood pressure or heart rate at 90% twitch blocking doses were either minor or absent. The potency and time course of action of Org 9991 remained similar in all four species: i.e. 90% block at ca 200-300 micrograms kg-1; onset time ca 1.2-1.9 min; duration 90% ca 4.5-8.9 min. This study suggests that 16-N-homopiperidinium analogues of vecuronium may provide leads in the quest for a potent non-depolarizing replacement for suxamethonium.

Androstanols↗
PubMed1991

Hemocue--a new haemoglobinometer in the clinic.

The accuracy of the Hemocue, a portable haemoglobinometer, was tested on 29 patients undergoing open-heart surgery, and the results were compared with the haemoglobin values obtained from the hospital laboratory. Special attention was paid to the lower range of haemoglobin values and the simplicity and speed of operating the meter. The correlation between the methods was good (r = 0.965). The limits of agreement were 0.0323 +/- 0.705 mmol l-1 (95% confidence level).

Adolescent↗
PubMed1990

Intrathecal somatostatin produces effects dependent on the interval between catheter implantation and drug injection.

Intrathecal (i.t.) injection of somatostatin has been reported to depress nociceptive reflexes as well as to cause severe disturbance of somatomotor performance. The present study was designed to assess the dependence of these effects on the dose and the interval between implantation of the catheter and i.t. injection of somatostatin in rats. The effects produced by i.t. injection of somatostatin consisted of an increase in the response latencies of nociceptive responses to noxious heat, impairment of motor performance and grooming behavior, convulsions, and death. Except for grooming behavior, these were related in incidence and degree to the dose and the interval, the potency of somatostatin being highest at short intervals. Sham operations also affected the effectiveness of somatostatin.

Animals↗