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Biomedical subjects

J Szewczykowski

Publications and source records attributed to J Szewczykowski.

At least 19 recordsLinked to original sources
PubMed1983

Quantitative CT assessment of furosemide- and mannitol-induced changes in brain water content.

We studied the effects of two commonly employed antiedema agents, mannitol and furosemide, on CT brain density in eight patients with primary and metastatic brain tumors. Noncontrast CTs were performed before and after IV furosemide or IV mannitol, and serial blood samples were analyzed for osmolality. Computer-generated frequency histograms of CT numbers from "before-and-after" brain slices were using quantile-quantile (QQ) plots and the Kruskal-Wallis statistic. After IV mannitol, there was a progressive increase in CT brain density, which corresponded to an upward shift in the QQ plot over the range 0 to 70 Hounsfield units. The differences between baseline and posttreatment histograms for mannitol patients were significantly different from controls, and maximum differences coincided with peak serum osmolality. No statistically significant effects were observed in the furosemide group despite maximal diuresis. The relative magnitude of the quantitative changes observed after mannitol and furosemide administration are consistent with anticipated changes in brain water content.

Brain Edema↗
PubMed1977

A fast method of estimating the elastance of the intracranial system.

The authors describe a fast method for estimating the elastance of the intracranial system in man. The method consists in constructing the so-called amplitude-pressure (Amp-P) curve which describes the relationship between the amplitude of pulse-related oscillations in cerebrospinal fluid pressure and the basic level of intracranial pressure. The Amp-P curve consists of two straight lines, and the point of intersection of these lines is thought to indicate the intracranial pressure level at which there occurs a qualitative change in the functioning of compensatory mechanisms of the intracranial system. The authors applied the method to examine the Amp-P curves of 10 patients without intracranial pathology and found that they provide a good description of the state and dynamics of the intracranial system. Preliminary data obtained in patients with intracranial pathology indicate that the method is a valuable tool in the diagnosis and treatment of neurosurgical patients.

Adult↗
PubMed1977

[Effect of sudden decompression on tissue pressure in the brain and the cerebrospinal fluid pressure].

Extracranial hypertension was produced in cats by means of epidural compression with a baloon. After 2 hours of compression sudden decompression was performed and tissue pressure was compared at symmetrical sites of cerebral hemispheres with cerebrospinal fluid pressure measured in the cisterna magna. It was found that symmetrical tissue pystem, which was due probably to early oedema developing in the compressed area.

Animals↗
PubMed1976

A method of estimating intracranial decompensation in man.

A new method of estimating intracranial decompensation in man is described. An on-line computer system is connected to an intracranial pressure (ICP) monitoring system to compute regression plots of mean ICP vs standard deviation; standard deviation is used as a measure of ICP instability. Two zones with distinctly different slopes are a characteristic feature of these plots. It is thought that the changes of slope signify intracranial decompensation.

Humans↗
PubMed1975

A computerized neurosurgical intensive care system.

A specialized neurosurgical data acquisition and processing system was developed and applied in practice to monitor some 60 patients after head injury or neurosurgical operations. At first the system allowed off-line operation, and the experiences thus gained made it possible to implement the system in its present form for real-time on-line patient monitoring. The algorithms prepared in our laboratory allow rapid and concise presentation of results and have proved their usefulness in clinical practice. The main parameters of interest in neurosurgery are intracranial pressure (ICP) and the volume of cerebrospinal fluid (CSF) drained from one of the lateral ventricles. Examples of statistical analysis of both these variables, and their presentation in the form of tables, diagrams and histograms are given.

Adolescent↗
PubMed1975

Computer-assisted analysis of intraventricular pressure after mannitol administration.

The effect of prolonged mannitol infusion upon intraventricular pressure was investigated with the aid of a specially-designed automatic digital recording system; the data recorded were processed off-line by a minicomputer. The character of the pressure curves is thought to result from interaction between the mannitol effect and the observed system's shifting equilibrium position, which is caused by other factors. The character of the pressure curves prior to mannitol infusion must be taken into consideration in estimating the actual effect of the drug; the authors suggest that in certain cases it might be possible to decrease further the rate of mannitol administration. The advantages of statistical approach to the evaluation of intracranial pressure variations are discussed.

Analysis of Variance↗
PubMedDate not supplied

[System of rapid automatic digital recording of cerebrospinal fluid pressure].

The authors describe a system for rapid digital automatic recording of cerebrospinal fluid pressure. The results are recorded in numerical form by a recorder. Owing to this quantitative expression of results the subjective evaluation of analog curves is avoided. The system may be used also to measure other slowly changing physiological processes.

Cerebrospinal Fluid↗