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H C Schuyt

Publications and source records attributed to H C Schuyt.

12 recordsLinked to original sources
PubMed1996

Measurement and reduction of nitrous oxide in operating rooms.

In a program designed to lower exposure to anesthetic gases, nitrous oxide in the breathing zone of anesthesiologists was continuously monitored by means of a direct reading apparatus and a specially designed collar. Initially, the average concentration during anesthesia in intubated patients, determined in 30 operating rooms of seven hospitals, was 68 ppm. During mask anesthesia in children, it was 407 ppm (nine operating rooms, nine hospitals). The main hygienic measures were: a check of the anesthesia apparatus, improvement of the general ventilation in the operating room, and the application of a "double mask." With a combination of measures, the concentration during anesthesia in intubated patients was reduced from 61-90 ppm to 2-15 ppm. During mask anesthesia in children, the concentration decreased from 134-764 ppm to 9-42 ppm. The monitoring system used reveals important differences in the exposure during the separate phases of the anesthesia (induction, maintenance, and extubation). It also indicates which factors determine the exposure of the anesthetist and allows accurate determination of the personal exposure.

Adult↗
PubMed1983

Influence of high-dose alfentanil anaesthesia on the electroencephalogram: correlation with plasma concentrations.

The influence of high-dose alfentanil-oxygen-air anaesthesia on the electroencephalogram was studied in 10 patients undergoing elective coronary artery surgery. Premedication was either lorazepam 5 mg orally (n = 5) or morphine 10 mg and hyoscine 0.4 mg i.m. (n = 5). Anaesthesia was induced with alfentanil 125 micrograms kg-1 h-1 and maintained by a continuous infusion at a rate of 0.25-0.5 mg kg-1. The EEG was recorded on the day before surgery, continuously from before induction of anaesthesia until the end of surgery and at hourly intervals after operation. Blood samples were withdrawn at intervals during and after surgery for measurement of plasma alfentanil concentrations. Anaesthesia was associated with large increases in delta activity and reduction in higher frequency components. There was less synchronization of the EEG than is observed with fentanyl or sufentanil. Spindle activity was prominent in 70% of patients. The changes in the EEG during recovery tended to occur abruptly and there was no obvious correlation between the EEG and plasma concentrations of alfentanil. There was a significant correlation between the total dose of alfentanil and the awake plasma concentration (r = 0.94; P less than 0.01). Plasma concentrations decreased exponentially after operation, with a mean half-life of 304 +/- 54 min.

Alfentanil↗
PubMed1982

A model for provoking ischemic necrosis in rat liver parenchyma and its quantitative analysis.

Ischemia in the left lateral and median lobe of the rat liver was provoked by means of a small clip, as applied in human microvascular surgery. After various periods of ischemia (30, 40, 50, 60 and 90 min) the blood flow to these lobes was restored. Twenty-four hours after restoration, the extent of necrosis was estimated quantitatively via morphometric measurements of the relative surfaces of necrotic tissue in photomicrographs of gallocyanin-stained serial sections. After periods of ischemia longer than 40 min, the percentage of necrotic tissue increased linearly with the period of clamping. After 40 min of total ischemia the changes in hepatocytes are for the greater part reversible, whereas after 90 min the majority of the cells have passed the "point of no return" and will no more be able to maintain their integrity.

Animals↗
PubMed1980

Growth pattern of individual liver cells after partial hepatectomy in the rat.

The growth (i.e. changes in protein content) of isolated parenchymal cells of rat liver after partial hepatectomy has been investigated cytophotometrically. 3, 14 and 56 days after operation in rats of different age, no statistically significant differences could be measured in the Naphthol Yellow S-protein content of the most commonly found types of parenchymal cells in comparison with controls of the same age. An exaggeration of the hyperplasia of binuclear diploid (BD) and mononuclear tetraploid (MT) cells, characteristic for normal postnatal growth, could not be detected in any of the age groups investigated (30, 65 and 99 at operation). Consequently, it appears that the accelerated growth after partial hepatectomy mainly takes place by a growth mechanism primarily based on multiplication of cells (hypertrophy) as usually found in the embryonic period.

Animals↗
PubMed1979

Growth patterns of rat hepatocytes during postnatal development.

During postnatal growth in the liver of the rat, a characteristic shift towards binuclear cells and cells of higher ploidy class occurs. When the protein content of individual isolated hepatocytes of different ploidy classes is analysed cytophotometrically using the specific protein stain Naphthol Yellow S, it appears that the growth in mass in the period 30-99 days is due mainly to increase of protein content of binuclear diploid (BD) and mononuclear tetraploid (MT) cells. The mononuclear diploid (MD) cells play a quickly diminishing role in the parenchymal population after the initial growth phase and cells of highest ploidy degree remain unimportant quantitatively. The quickly growing BD and MT cells only reach a Naphthol Yellow S protein value twice that of MD cells after a certain period of growth, whereas changes in protein content are slight or absent from 99 days onwards in all cell types investigated.

Aging↗
PubMed1978

An improved method in rabbit intubation and thymectomy.

A procedure is developed for endotracheal intubation followed by positive pressure ventilation anaesthesia, allowing major thoracic surgery, including thymectomy, to be performed in the young and adult rabbit. A method is described to bring the animal in a position favourable for thymectomy. A detailed description is given of a thymus ablation technique in which the thoracic wall is left intact.

Animals↗
PubMed1977

An improved method of tracheal intubation in the rabbit.

A rabbit to be intubated was anesthetized and placed in a supine position with its head back at a 45 degree angle. A speculum made of spring steel and cord was used to hold the mouth open. The tongue was held to one side, an infant size laryngoscope was inserted in the direction of the larynx, and an uncuffed nasal/oral tube was introduced into the mouth. The tube was then passed into the larynx during inspiration and held in place in the mouth and a specially designed bit.

Animals↗