Resistance to Outflow of Cerebrospinal Fluid Determined by Bolus Injection Technique and Constant Rate Steady State Infusion in Humans

Neurosurgery ◽  
1985 ◽  
Vol 16 (3) ◽  
pp. 336-340 ◽  
Author(s):  
Michael Kosteljanetz
Keyword(s):  
Cerebrospinal Fluid ◽  
Steady State ◽  
Bolus Injection ◽  
Point Of View ◽  
Injection Technique ◽  
Communicating Hydrocephalus ◽  
Constant Rate ◽  
High Degree ◽  
Infusion Technique

Abstract Two methods for the determination of resistance to the outflow of cerebrospinal fluid, the bolus injection technique and the constant rate steady state infusion technique, were compared. Thirty-two patients with a variety of intracranial diseases (usually communicating hydrocephalus) were studied. There was a high degree of correlation between the resistance values obtained with the two methods, but values based on the bolus injection technique were systematically and statistically significantly lower than those obtained with the constant rate infusion test. From a practical point of view. both methods were found to be applicable in a clinical setting.

scholarly journals Levofloxacin Disposition in Cerebrospinal Fluid in Patients with External Ventriculostomy

2003 ◽  
Vol 47 (10) ◽  
pp. 3104-3108 ◽  
Author(s):  
Federico Pea ◽  
Federica Pavan ◽  
Ennio Nascimben ◽  
Claudio Benetton ◽  
Pier Giorgio Scotton ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Steady State ◽  
Bacterial Meningitis ◽  
Acute Bacterial Meningitis ◽  
Terminal Phase ◽  
Communicating Hydrocephalus ◽  
Synergistic Activity ◽  
Dosing Interval ◽  
Concentration Time ◽  
Meningeal Inflammation

ABSTRACT In vitro levofloxacin exhibits both potent or intermediate activity against most of the pathogens frequently responsible for acute bacterial meningitis and synergistic activity with some beta-lactams. Since levofloxacin was shown to penetrate the cerebrospinal fluid (CSF) during meningeal inflammation both in animals and in humans, the disposition of levofloxacin in CSF was studied in 10 inpatients with external ventriculostomy because of communicating hydrocephalus related to subarachnoid occlusion due to cerebral accidents who were treated with 500 mg of levofloxacin intravenously twice a day because of extracerebral infections. Plasma and CSF concentration-time profiles and pharmacokinetics were assessed at steady state. Plasma and CSF levofloxacin concentrations were analyzed by high-pressure liquid chromatography. The peak concentration of levofloxacin at steady state (C max ss)was 10.45 mg/liter in plasma and 4.06 mg/liter in CSF, respectively, with the ratio of the C max ss in CSF to the C max ss in plasma being 0.47. The areas under the concentration-time curves during the 12-h dosing interval (AUC0-τs) were 47.69 mg · h/liter for plasma and 33.42 mg · h/liter for CSF, with the ratio of the AUC0-τ for CSF to the AUC0-τ for plasma being 0.71. The terminal-phase half-life of levofloxacin in CSF was longer than that in plasma (7.02 ± 1.57 and 5.51 ± 1.36 h, respectively; P = 0.034). The ratio of the levofloxacin concentration in CSF to the concentration in plasma progressively increased with time, from 0.30 immediately after dosing to 0.99 at the end of the dosing interval. In the ventricular CSF of patients with uninflamed meninges, levofloxacin was shown to provide optimal exposure, which approximately corresponded to the level of exposure of the unbound drug in plasma. The findings provide support for trials of levofloxacin with twice-daily dosing in combination with a reference beta-lactam for the treatment of bacterial meningitis in adults. This cotreatment could be useful both for overcoming Streptococcus pneumoniae resistance and for enabling optimal exposure of the CSF to at least one antibacterial agent for the overall treatment period.

Distribution of H+ and HCO3 minus between CSF and blood during metabolic alkalosis in dogs

1975 ◽  
Vol 228 (4) ◽  
pp. 1141-1144 ◽  
Author(s):  
EG Pavlin ◽  
ttf Hornbein
Keyword(s):  
Cerebrospinal Fluid ◽  
Steady State ◽  
Metabolic Alkalosis ◽  
Extracellular Fluid ◽  
Ion Distribution ◽  
Brain Extracellular Fluid ◽  
Dc Potential ◽  
Arterial Plasma ◽  
Lumbar Cerebrospinal Fluid

In anesthetized, paralyzed dogs ventilated to maintain a normal PaCO2, metabolic alkalosis was induced and held constant over 6 h by infusion of sodium bicarbonate. Determination of pH, PCO2, (HCO3 minus), and (lactate) in cisternal and lumbar cerebrospinal fluid (CSF) and in arterial plasma together with measurement of the CSF/plasma DC potential differences permitted calculation of the electrochemical potential difference (mu) for H+ and HCO3 minus; measurements were made prior to induction of metabolic alkalosis at pHa equal to 7.40, as soon after induction as stable arterial values were achieved and 3, 4.5, and 6 h thereafter. A steady state for ion distribution was reached by 4.5 h. Values of mu for H+ and HCO3 minus returned to +0.1 and +0.9 mV of control at 6 h for cisternal CSF and +0.6 and minus 0.4 mV for lumbar CSF. This return of muH+ and muHCO3 minus close to control in the steady state is compatible with passive distribution of these ions between brain extracellular fluid and blood.

Cerebrospinal fluid conductance and compliance of the craniospinal space in normal-pressure hydrocephalus

1979 ◽  
Vol 51 (4) ◽  
pp. 521-525 ◽  
Author(s):  
Svend Erik Børgesen ◽  
Flemming Gjerris ◽  
Søren Claus Sørensen
Keyword(s):  
Cerebrospinal Fluid ◽  
Normal Pressure Hydrocephalus ◽  
Bolus Injection ◽  
Normal Pressure ◽  
Poor Correlation ◽  
Injection Technique ◽  
Pressure Monitoring ◽  
Perfusion Technique ◽  
Content Type

✓ Conductance to outflow of cerebrospinal fluid (CSF) has been measured by both a lumboventricular perfusion and a bolus injection method in 24 patients with normal-pressure hydrocephalus. One purpose was to investigate whether the less time-consuming technique of bolus, injection gave results comparable to the results obtained by the lumboventricular perfusion technique. There was a poor correlation between the results obtained by the two measurements of conductance to outflow of CSF. It is concluded that the bolus-injection technique cannot substitute for the lumboventricular perfusion test. Compliance of the CSF space was measured by the bolus injection. The presence of B-waves, recorded from long-term intraventricular pressure monitoring, could be correlated to the sum of conductance to outflow and compliance. The correlation offers a possible explanation of the nature of B-waves.

Significance of the So-Called Absorptive Reserve in Communicating Hydrocephalus

Neurosurgery ◽  
1981 ◽  
Vol 8 (5) ◽  
pp. 525-530 ◽  
Author(s):  
Frederick H. Sklar ◽  
Chester W. Beyer ◽  
Jan T. Diehl ◽  
Kemp W. Clark
Keyword(s):  
Cerebrospinal Fluid ◽  
Absorptive Capacity ◽  
Communicating Hydrocephalus ◽  
Physiological Range ◽  
Resting Pressure ◽  
Pressure Parameter ◽  
Infusion Technique ◽  
Csf Absorption

Abstract Twelve patients with communicating hydrocephalus were studied with a servocontrolled lumbar infusion technique to measure net cerebrospinal fluid (CSF) absorptive capacity and resting pressure. Each patient showed a significant absorptive reserve; the rate of CSF absorption exceeded the rate of formation over a physiological range of pressure. The size of the ventricles did not correlate with either the absorptive capacity or the resting pressure parameter, or both. The data suggest that communicating hydrocephalus does not reflect a simple imbalance between the rates of CSF formation and absorption. Other factors must be of etiological importance and are considered in the discussion.

scholarly journals Etiological Profile and Resistance of Bacterial Isolates from Samples of Cerebrospinal Fluid in Kosovo, during the years 2014-2019

2020 ◽  
Author(s):  
Rita Qarkaxhija
Keyword(s):  
Public Health ◽  
Cerebrospinal Fluid ◽  
Antimicrobial Resistance ◽  
Antimicrobial Agents ◽  
Prolonged Exposure ◽  
Point Of View ◽  
Annual Reports ◽  
Adaptive Selection ◽  
Inflammatory Conditions

Cerebrospinal fluid is a dynamic, metabolically active substance that has numerous important functions. It is considered a valuable diagnostic aid in assessing infectious inflammatory conditions, involving the brain, spinal cord, and meninges. The discovery and use of antimicrobial agents has fundamentally changed medicine from a therapeutic point of view, enabling the treatment of many diseases once considered threatening and deadly. However, after prolonged exposure of various microorganisms to these agents, the development of antimicrobial resistance has been enabled through the adaptive selection mechanism. The emergence of this resistance in the main pathogenic microorganisms is a very problematic and threatening issue in public health, making it a global problem. Resistance of various microorganisms in Kosovo, according to annual reports of CAESAR, compared to other European countries, is quite worrying. It reaches the tops of the lists for high resistance, along with other Balkan countries, such as Serbia, Montenegro, and North Macedonia. The purpose of this research was to define the etiology and level of resistance of microorganisms to antimicrobial agents, which are encountered in invasive samples of cerebrospinal fluid. This research is a retrospective, descriptive type analysis, which includes the data gathered from January 1, 2014 to May 7, 2019. We have a total of 185 bacteria isolated from 1499 isolates, conducted at the National Institute of Public Health in Kosovo. The determination of antimicrobial resistance was performed according to automated systems and the method of disk diffusion.

CSF dynamics and pressure-volume relationships in communicating hydrocephalus

1986 ◽  
Vol 64 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Michael Kosteljanetz
Keyword(s):  
Cerebrospinal Fluid ◽  
Bolus Injection ◽  
Formation Rate ◽  
Cerebral Atrophy ◽  
Pulse Amplitude ◽  
Volume Index ◽  
Communicating Hydrocephalus ◽  
Csf Dynamics ◽  
Content Type ◽  
Normal Individuals

✓ Twenty-nine patients consecutively admitted with a diagnosis of communicating hydrocephalus underwent 1) continuous intracranial pressure (ICP) monitoring; 2) pressure-volume studies; and 3) measurement of resistance to outflow of cerebrospinal fluid (Rout). The two latter calculations were made by the bolus injection and pressure-volume index (PVI) techniques. In 19 patients mean ICP never exceeded 15 mm Hg. In the other 10 patients varying degrees of mildly raised ICP was noted. The frequency of waves at ½ to 2/min varied from 3% to 58%. The ICP pulse amplitude ranged from 0.5 to 10 mm Hg, and PVI from 4.6 to 18.2 ml. The Rout ranged from 2.5 to 31.4 mm Hg/ml/min, and was linearly correlated to the ICP. Thus, patients with a higher Rout also had a higher ICP as compared with patients with lower Rout, yet ICP could still be within limits considered normal. The cerebrospinal fluid dynamics (formation rate × resistance) contributed much more to the ICP than in normal individuals. It is postulated that communicating hydrocephalus represents one endpoint of a continuum, where the preceding phase is high-pressure and high-resistance hydrocephalus as, for instance, is seen after subarachnoid hemorrhage. In some patients, there is a possibility of cerebral atrophy accompanied by otherwise insignificant increased Rout. In this study, the PVI technique proved to be a fast and safe method of measuring Rout.

scholarly journals The design of experiments using isotopes for the determination of the rates of disposal of blood-borne substrates in vivo with special reference to glucose, ketone bodies, free fatty acids and proteins

1973 ◽  
Vol 136 (3) ◽  
pp. 503-518 ◽  
Author(s):  
Dennis F. Heath ◽  
Roger N. Barton
Keyword(s):  
Fatty Acids ◽  
Steady State ◽  
Free Fatty Acids ◽  
Ketone Bodies ◽  
Specific Radioactivity ◽  
Constant Infusion ◽  
Time Curve ◽  
Constant Rate

1. The two well-known methods of estimating rates of irreversible disposal (R) of blood-borne substrates in vivo by isotope experiments involve estimating the specific radioactivity (S) of the substrate in blood either after single intravenous injection of labelled substrate or during its infusion at a constant rate. The value of R is calculated from the S–time curve, usually by assuming: (i) a metabolic steady state with respect to substrate, (ii) the passage of all substrate through the blood, and (iii) the absence of certain types of recycling via blood. 2. In a theoretical investigation we show how experiments can be performed and R calculated from analyses of blood when one or more of the above assumptions is unjustified, by using glucose, ketone bodies, plasma free fatty acids and proteins as examples. In general the methods require single injection procedures, with estimation of the total quantity of label in the substrate in blood and the substrate concentration instead of only S. Such values give estimates of R with standard errors even when only one blood specimen is taken from each of a group of animals, as is convenient when working with small animals or substrates in low concentration, and when the animals are in a non-steady state in which constant infusion procedures are invalid. 3. Similar methods give the fraction of label injected as one compound which passes through another (the isotopic yield). 4. The methods are not always applicable, and cannot be applied to plasma proteins in some pathological conditions. A questionnaire for assessing their applicability is given.

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