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Biomedical subjects

D Vogelaers

Publications and source records attributed to D Vogelaers.

At least 37 records · Page 2Linked to original sources

Concentrations in plasma and safety of 7 days of intravenous itraconazole followed by 2 weeks of oral itraconazole solution in patients in intensive care units.

Pharmacokinetics and safety of a hydroxy-beta-propyl solution of itraconazole were assessed in 16 patients in an intensive care unit. On the first 2 days, four 1-h infusions of 200 mg were given at 0, 8, 24, and 32 h. From day 3 to 7, inclusive, a single 1-h infusion of 200 mg of itraconazole was given daily. The intravenous (i.v.) treatment was directly followed by repeated administrations of an oral solution of itraconazole at a dosage of either 200 mg once daily or 200 mg twice daily (b.i.d.). During i.v. treatment, steady-state concentrations of itraconazole and hydroxy-itraconazole in plasma were reached within 48 and 96 h, respectively. At the end of i.v. treatment, mean (+/- standard deviation) itraconazole and hydroxy-itraconazole trough concentrations in plasma were 0.344 +/- 0.140 and 0.605 +/- 0.205 microg/ml, respectively. After the 2-week oral follow-up of 200 mg once daily the mean trough concentration had decreased to 0.245 microg/ml, whereas after 200 mg b.i.d. it increased to 0.369 microg/ml. Diarrhea during oral treatment appeared to be dose related and may be due to the solvent hydroxypropyl-beta-cyclodextrin. More severe laboratory abnormalities were noted during the i.v. than the oral treatment phase, probably related to more severe illness in that period of intensive care, but none proved clinically important. These results suggest that plasma itraconazole levels above 0.250 microg/ml may be achieved and maintained with the 1-week i.v. schedule followed by b.i.d. oral administration, whereas the once-daily oral follow-up seems to be a suboptimal treatment.

2-Hydroxypropyl-beta-cyclodextrin↗

Ultrasound and CT changes of liver parenchyma in acute schistosomiasis.

Acute schistosomiasis in travellers to endemic regions often remains unrecognized. Early diagnosis is important to avoid progression to chronic disease. Diagnosis is based on clinical, epidemiological and laboratory data. The role of imaging techniques as diagnostic tools remains to be established in acute clinical schistosomiasis. We describe hypodense nodules in the liver on ultrasound and CT scanning in a patient with acute schistosomiasis (Katayama syndrome). To our knowledge this is the first description of nodular hepatic lesions in acute schistosomiasis.

Acute Disease↗

Xanthomas due to generalized oedema.

A unique case of normolipaemic eruptive xanthomas due to generalized oedema is described. We propose that in this patient eruptive xanthomas were caused by the capillary leak syndrome. The increased vascular permeability could be responsible for leakage of lipoproteins into the dermis with subsequent phagocytosis by histiocytic cells.

Acute Disease↗

Recurrent pericardial effusion as a result of chronic pancreatitis. Successful treatment with somatostatin.

We report a well-documented case of relapsing chronic calcifying pancreatitis with recurrent pleural and pericardial effusions during episodes of clinical and biochemical relapse of the pancreatitis. Pericardial effusions in association with pancreatitis have been reported only very occasionally, almost exclusively in chronic alcoholic pancreatitis with pseudocyst formation. Our successful conservative treatment consisted of parenteral nutrition and a continuous infusion of somatostatin for 6 weeks. We discuss other reported cases and proposed mechanisms of pathogenesis.

Adult↗

Hepatotoxicity of N, N-dimethylformamide (DMF) in acute poisoning with the veterinary euthanasia drug T-61.

1. We report on a patient who was resuscitated after a suicide attempt with the veterinary euthanasia product T-61 and treated with N-acetylcysteine (NAC) to prevent hepatotoxicity from N,N-dimethylformamide (DMF), the solvent of T-61. 2. Serum concentrations of DMF were high as compared with values published on occupational exposure. 3. The patient showed only a transient increase in liver enzymes with eventually a full recovery. 4. The hepatoprotective effect of NAC was studied in a rat model using the rise in serum sorbitol dehydrogenase (SDH) as a marker for DMF-induced hepatotoxicity. 5. Four series of randomized, controlled and double-blind experiments were carried out and consistently showed a lower increase in SDH in NAC-treated animals in each series. The difference was statistically significant only when the data of the 4 series were pooled. This is probably due to the large interindividual variations in the effect of DMF. 6. We hypothesize that in the rat NAC may have a protective effect. Whether NAC is also protective in patients, in which it is administered after exposure to DMF, cannot be concluded from the present experiments.

Acetylcysteine↗

Transmission of nosocomial infection by intravenous catheters: preventive strategies.

Intravascular catheter-related bacteraemia puts a major burden on health care due to its associated morbidity and mortality. Because of difficulties in the diagnosis and the consequences of catheter infections, prevention of infection is of the utmost importance. Depending on the setting, the intrinsic and extrinsic risk factors and the patient's personal characteristics, different strategies can be used, but they all focus on catheter care during placement and maintenance of the lines. In this review of the literature, recent data on the aetiology, diagnosis and prevention of catheter-related infections will be discussed.

Belgium↗

[Resuscitation in heart arrest due to severe hypothermia].

Two patients were resuscitated after cardiopulmonary arrest due to severe hypothermia. The first patient, a 76-year-old man, had ventricular fibrillation resistant to conventional therapy; he was rapidly rewarmed by means of cardiopulmonary bypass. In the second patient, a 77-year-old woman, classical resuscitation led to restoration of spontaneous circulation. The patient was subsequently rapidly rewarmed with hemodialysis with fluid of 40 degrees C. We conclude that rapid rewarming with cardiopulmonary bypass is the treatment of choice in severely hypothermic patients presenting with cardiac arrest that is resistant to conventional therapy. Hemodialysis seems a suitable technique in patients who remain deeply hypothermic after resuscitation. However, it is difficult to assess its value because of the lack of clinical studies comparing this technique with other procedures.

Aged↗

Cholinesterase reactivation in organophosphorus poisoned patients depends on the plasma concentrations of the oxime pralidoxime methylsulphate and of the organophosphate.

We measured in nine patients, poisoned by organophosphorus agents (ethyl parathion, ethyl and methyl parathion, dimethoate, or bromophos), erythrocyte and serum cholinesterase activities, and plasma concentrations of the organophosphorus agent. These patients were treated with pralidoxime methylsulphate (Contrathion), administered as a bolus injection of 4.42 mg.kg-1 followed by a continuous infusion of 2.14 mg.kg-1/h, a dose regimen calculated to obtain the presumed "therapeutic" plasma level of 4 mg.l-1, or by a multiple of this infusion rate. Oxime plasma concentrations were also measured. The organophosphorus agent was still detectable in some patients after several days or weeks. In the patients with ethyl and methyl several days or weeks. In the patients with ethyl and methyl parathion poisoning, enzyme reactivation could be obtained in some at oxime concentrations as low as 2.88 mg.l-1; in others, however, oxime concentrations as high as 14.6 mg.l-1 remained without effect. The therapeutic effect of the oxime seemed to depend on the plasma concentrations of ethyl and methyl parathion, enzyme reactivation being absent as long as these concentrations remained above 30 micrograms.l-1. The bromophos poisoning was rather mild, cholinesterases were moderately inhibited and increased under oxime therapy. The omethoate inhibited enzyme could not be reactivated.

Adult↗

Direct comparison of [13N]ammonia and [15O]water estimates of perfusion with quantification of regional myocardial blood flow by microspheres.

BACKGROUND: Both [13N]ammonia and [15O]water have been used to quantify myocardial blood flow with positron emission tomography using appropriate tracer kinetic models. A direct comparison of the two tracers with radioactive microspheres has not been performed in the same experimental preparation. METHODS AND RESULTS: The two tracers have been tested for myocardial blood flow quantification in closed-chest dogs with circumflex coronary stenosis or permanent occlusion at rest and during adenosine-induced hyperemia. [13N]ammonia- and [15O]water-derived myocardial blood flow values have been compared with radiolabeled microspheres. Validation studies consisted of simultaneous measurements of blood flow with positron emission tomography and microspheres over a wide range of flow values. Blood pool and regional tissue activity curves were fitted with a three-compartment model for [13N]ammonia with and without arterial metabolite correction and with a single-tissue-compartment model for [15O]water. A correction for finite-resolution effect before the fit was also applied. In large regions of interest (5 cm3), a good correlation between the microsphere method and [13N]ammonia (with metabolite correction) was obtained (y = 3 + 0.78x, r = 0.94). The correlation with microspheres was slightly better with [15O]water (y = -3 + 0.89x, r = 0.97). Similar correlations were achieved in smaller regions of interest (1 cm3) as well as in akinetic segments and in central infarct regions. CONCLUSIONS: Positron emission tomography with appropriate tracer kinetic models using [13N]ammonia and [15O]water provides an accurate quantitative method for measuring regional myocardial blood flow over a wide range of flow values in normally contracting or akinetic canine myocardium in the absence and in the presence of infarction.

Ammonia↗

Recovery of regional contractile function and oxidative metabolism in stunned myocardium induced by 1-hour circumflex coronary artery stenosis in chronically instrumented dogs.

Stunned myocardium produced by 1 hour of critical coronary artery stenosis was evaluated for alteration in regional mechanical function and overall oxidative and fatty acid metabolism by positron emission tomography (PET) in chronically instrumented dogs. Twenty-seven dogs, chronically instrumented for measurements of left ventricular pressure and regional myocardial wall thickening in normal and ischemic zones, were subjected to a 1-hour period of myocardial ischemia produced by graded left circumflex coronary artery stenosis, resulting in minimal residual flow. Mean transmural myocardial flow during 1-hour coronary stenosis decreased to 0.34 +/- 0.04 ml/min per gram in the ischemic zones (normal zone transmural flow, 0.96 +/- 0.10 ml/min per gram). Systolic wall thickening in the ischemic zone was almost completely abolished (-97 +/- 4%). On reperfusion, systolic wall thickening immediately resumed but remained depressed. Progressive recovery was noted with time. At 24 hours, systolic wall thickening was still depressed (-20 +/- 6%, p < 0.01). At 1 week, wall thickening had completely recovered and was no longer significantly different from the control condition. In addition, the absence of necrosis at the site of wall thickness measurements was confirmed at autopsy in all dogs. No abnormalities were found by electron microscopy in four dogs undergoing myocardial biopsies at the time of PET studies. Dynamic PET studies using [1-11C]acetate tracer (performed at 6 hours, 1 week, and 2 weeks after reperfusion) and [1-11C]palmitic acid tracer (performed at 6 hours, 12 hours, 24 hours, 1 week, and 2 weeks after reperfusion) allowed the computation of regional tissue time-activity curves in different regions of interest at different times during follow-up. Despite full reperfusion, abnormal [1-11C]acetate and [1-11C]palmitic acid kinetics were observed in the posterior segments, previously subjected to ischemia, as evidenced by a significant decrease in the slope of the early 11C clearance curve component. Repeat PET studies revealed progressive normalization of overall oxidative metabolism and fatty acid metabolism, which paralleled the time course of recovery of mechanical function. Thus, myocardial ischemia, produced by 1-hour coronary artery stenosis, followed by full reperfusion is associated with a prolonged period of postischemic mechanical and metabolic dysfunction. This transient reduction in oxygen delivery induced a prolonged impairment in fatty acid beta-oxidation as well as a reduction in overall oxidative metabolism despite full reoxygenation. A similar time course for recovery of function and metabolism was observed.

Acetates↗

Plasma concentrations of pralidoxime methylsulphate in organophosphorus poisoned patients.

Using pharmacokinetic data from healthy human volunteers in a bicompartmental pharmacokinetic model, a repeated dose scheme for pralidoxime methylsulphate (Contrathion) was developed producing plasma levels remaining above the assumed "therapeutic concentration" of 4 mg.l-1. Using the same data, it was found that a concentration of 4 mg.l-1 could also be obtained by a loading dose of 4.42 mg.kg-1 followed by a maintenance dose of 2.14 mg.kg-1.h-1. In order to study the pharmacokinetic behaviour of pralidoxime in poisoned patients, this continuous infusion scheme was then applied in nine cases of organophosphorus poisoning (agents: ethyl parathion, ethyl and methyl parathion, dimethoate and bromophos), and the pralidoxime plasma levels were determined. The mean plasma levels obtained in the various patients varied between 2.12 and 9 mg.l-1. Pharmacokinetic data were calculated, giving a total body clearance of 0.57 +/- 0.27 l.kg-1.h-1 (mean +/- SD), an elimination half-life of 3.44 +/- 0.90 h, and a volume of distribution of 2.77 +/- 1.45 l.kg-1.

Dose-Response Relationship, Drug↗

Intermediate syndrome due to prolonged parathion poisoning.

A parathion-poisoned patient with prolonged cholinesterase inhibition due to impaired hepatic metabolism and urinary excretion is reported. An intermediate syndrome characterized by respiratory paresis, weakness in the territory of several motor cranial nerves and of proximal limb and neck flexor muscles, persisted for 3 weeks. During this whole period, cholinesterase remained markedly reduced. Serial EMGs with repetitive nerve stimulation pointed to a combined pre- and postsynaptic disorder of neuromuscular transmission. Electron microscopy of an intercostal muscle biopsy showed focal degeneration at the poorly branched postsynaptic folds, and was considered to be nonspecific.

Acetylcholinesterase↗

Prolonged toxicity with intermediate syndrome after combined parathion and methyl parathion poisoning.

A prolonged type of organophosphate toxicity, previously characterized as the Intermediate Syndrome, has been recognized in 6 out of 7 prospectively studied patients poisoned by insecticide containing parathion and methyl parathion in equal proportions. The clinical characteristics included respiratory paresis, weakness in the territories of several motor cranial nerves, neck flexors and proximal limb muscles, and depressed tendon reflexes, all lasting for several days or weeks. Electromyography in the early stages disclosed diverse types of impaired neuromuscular transmission. EMG normalization preceded clinical recovery. Severe plasma butyrylcholinesterase and erythrocyte acetylcholinesterase inhibition persisted along with the occurrence of Intermediate Syndrome-related symptoms. We conclude that combined parathion and methyl parathion poisoning is more likely to induce Intermediate Syndrome than parathion poisoning alone. The mechanisms underlying this difference remain obscure. The Intermediate Syndrome shows clinical and electromyographic hallmarks of combined postsynaptic impairment of neuromuscular transmission.

Adult↗

Fibrinolysis and coagulation in patients with infectious disease and sepsis.

Sepsis is often associated with hemostatic dysfunction. This study aimed to relate changes in fibrinolysis and coagulation parameters to sepsis and sepsis outcome. Urokinase-type plasminogen activator (u-PA) antigen, tissue-type plasminogen activator (t-PA) antigen and activity, plasminogen activator inhibitor (PAI) type 1 antigen, PAI activity, antithrombin (AT) III activity, and protein C activity were measured in 24 patients suffering from sepsis or septic shock and the results were compared with those observed in 30 non-sepsis patients with severe infectious disease. The u-PA level was markedly increased in plasma of sepsis patients as compared to non-sepsis patients (11.5 +/- 9.4 versus 1.6 +/- 1.5 ng/ml, p less than 0.0001). PAI-1 antigen and t-PA activity showed a significant increase in sepsis patients (320 +/- 390 ng/ml versus 120 +/- 200 ng/ml, and 3.0 +/- 3.6 IU/ml versus 1.0 +/- 0.7 IU/ml, respectively, p less than 0.01). AT III was decreased in sepsis patients (58 +/- 28% in sepsis versus 79 +/- 26% in severe infectious disease, p less than 0.01) as was protein C (30 +/- 18% versus 58 +/- 27%, p less than 0.001). No significant difference was found for t-PA antigen nor for PAI activity. Nonsurvivors of sepsis were distinguished mainly by a high u-PA antigen level and increased t-PA activity. It is concluded that plasma u-PA antigen showed the strongest significant difference, among the parameters evaluated, between sepsis and severe infection. u-PA antigen may be of prognostic value in patients admitted to the medical intensive care unit for severe infectious disease.

Adult↗