Acute limb ischemia and heparin-induced thrombocytopenia: the value of echocardiography in eliminating a cardiac source of arterial emboli

We report an unusual thromboembolic event occurring during severe heparin-induced thrombocytopenia. A left intraventricular thrombus was diagnosed as the source of multiple arterial emboli, resulting in an initial cerebrovascular event and subsequent bilateral acute lower extremity ischemia requiring emergency surgery. No underlying heart disease was detected. Pathologic examination of the embolectomy specimen revealed fibrin platelet aggregates with rare white and red blood cells, consistent with a "white thrombus." We conclude that routine monitoring of platelet count should be performed in all patients receiving heparin to identify promptly individuals who have heparin-induced thrombocytopenia, and when thromboembolic complications occur in this setting, echocardiography is indicated to identify possible intracardiac sources for emboli, even in patients with previously known structurally intact hearts.

Thyroid function parameters during a selenium repletion/depletion study in phenylketonuric subjects

Phenylketonuric (PKU) subjects have a limited supply of selenium (Se) in their phenylalanine-restricted diet. A Se repletion (1 microgram Se/kg/day)/depletion study was conducted in PKU children to determine the effect of Se on thyroid function parameters. The initial plasma Se concentration (mean +/- SD: 0.26 +/- 0.12 mumol/L, p < 0.00003, n = 10) and glutathione peroxidase (GSH-Px) activity (140 +/- 58 U/L, p < 0.00003, n = 10) were significantly lower compared to age-matched controls. After 14 weeks of supplementation, the plasma Se concentration (mean +/- SD: 0.74 +/- 0.20 mumol/L) normalized (normal range: 0.57-1.15 mumol/L, mean +/- SD: 0.76 +/- 0.13 mumol/L, n = 32) and remained stable thereafter during repletion. Plasma GSH-Px activity reached normal values after 18 weeks of supplementation (312 +/- 57 U/L; normal range: 238-492 U/L, mean +/- SD: 345 +/- 54 U/L, n = 32) and increased significantly for up to eight weeks thereafter (332 +/- 52 U/L). Individual and mean thyroid parameters were initially normal in all cases. The mean concentrations of plasma thyroxine (T4: p < 0.025), free T4 (FT4: p < 0.01) and reverse triiodothyronine (rT3: p < 0.005) decreased to 75% of their initial value within three weeks of Se supplementation and remained stable thereafter, within a normal physiological range during selenium supplementation. They increased back to their initial values three weeks (T4: p < 0.05, FT4: p < 0.05) and six weeks (rT3: p < 0.025) respectively, after the end of the supplementation. In conclusion, Se supplementation modifies thyroid function parameters in Se-deficient PKU subjects most likely by an increase in activity of type I 5'-deiodinase (5'-DIase I).

[Dynamics of the nasal colonization by methicillin resistant Staphylococcus aureus in patients hospitalized in an intensive care unit]

Prospective study on MRSA nasal cariage was done during two months in an intensive care unit in Limoges University Hospital. Nasal swab specimens were taken daily and cultured on selective and non selective media. Sixty eight patients were included in this study (878 swab collected, 575 MRSA isolated). Patients mean âge was 62 years and stay period mean was 12.3 days (median: 7 days). Among these patients, 16 were already carrying MRSA when entering in the unit and 26 became positive for MRSA during their stay. The mean colonisation delay was 5.5 days (median 4 days). All patients, except one, have shown a nasal carriage during all their stay. During the study period, 17 patients became infected and only two patients neither carried nasal MRSA before and during infection. In all cases, glycopeptide treatment did not affect nasal carriage. Colonisation and infection risk factors were discussed.

Effects of selenium supplementation on thyroid hormone metabolism in phenylketonuria subjects on a phenylalanine restricted diet

Type I 5'-deiodinase was recently characterized as a selenocysteine-containing enzyme in humans and other mammals. Up to now, the effect of selenium (Se) supplementation on thyroid hormone metabolism in humans has only been reported in the very peculiar nutritional environment of Central Africa, where combined severe iodine and Se deficiency occurs. In this study, a group of phenylketonuria subjects with a low selenium status, but a normal iodine intake were supplemented with selenium to investigate changes in their thyroid hormone metabolism. After 3 wk of selenium supplementation (1 microgram/kg/d), both the concentrations of the prohormone thyroxine (T4) and the metabolic inactive reverse triiodothyronine (rT3) decreased significantly. Clinically, the phenylketonuria subjects remained euthyroid before and after selenium supplementation. The individual changes of plasma Se and glutathione peroxidase activity were closely associated with individual changes of plasma T4 and rT3.

[Reactive hemophagocytic syndrome: a probably underestimated cause of thrombocytopenia in intensive acre patients]

Thrombocytopenia is a common feature in ICU patients which occurs usually in case of infection or septic shock. Its mechanisms, which are often unclear, include the haemophagocytic syndrome initially linked with histiocytic proliferation but probably also associated with infectious diseases. This syndrome is characterized by a phagocytosis of medullar blood cells. Reactive haemophagocytic syndrome can probably lead to thrombocytopenia in ICU patients as in this case report of a E. Coli infection.

Crescentic glomerulonephritis and crystals within glomerular capillaries in an AIDS patient treated with foscarnet

We report on a 28-year-old AIDS patient who developed a rapidly progressive glomerulonephritis while being treated with foscarnet for cytomegalovirus retinitis. Renal biopsy showed crescentic proliferation related to crystals within the glomerular capillaries. The role of foscarnet in this unusual renal syndrome is discussed.

Sleep apnea incidence in maintenance hemodialysis patients: influence of dialysate buffer

A high prevalence of sleep disorders and sleep apnea syndrome in hemodialysis (HD) patients has been known for 10 years. Acetate, the buffer once most commonly used, favors intradialytic hypoxemia through hypoventilation and ventilation-perfusion changes. The aim of the present study was to assess the influence of buffer, acetate or bicarbonate, on sleep and ventilation during the night subsequent to an afternoon (2-7 p.m.) dialysis session. Ten patients, 8 males and 2 females, aged 35-71 years, dry weight 55-72 kg, on dialysis 15 h a week for 6-67 months, were randomly assigned first to acetate or bicarbonate, then to the other mode of treatment. After a series of six sessions using the same buffer, polysomnographic recordings from 9.00 p.m. to 6.00 a.m. were obtained. Sex, age, weight, data of first dialysis, blood pressure and sleep disorder-related symptoms were not correlated with the sleep apnea syndrome. Prolonged or important oxygen desaturations were never observed. Central apnea occurred more frequently during the night following acetate dialysis: x = 33 (0-180) versus 3 (0-15), p < 0.05. Obstructive apneas were not different. A defective modulation of ventilatory control after acetate HD might be held responsible for central apnea, which would constitute one more case for a widespread use of bicarbonate HD.

Localized brain proton NMR spectroscopy in young adult phenylketonuria patients

Localized proton magnetic resonance spectroscopy with short echo time (TE = 20 ms) was used to investigate biochemical changes in the cerebral white matter of 20 young adult patients (median 19 years) with phenylketonuria (PKU). Results were compared with those of a group of 12 age-matched healthy volunteers (median 25 years). Concentrations of N-acetyl-aspartate (NAA) and choline (Cho) relative to creatine (Cr) were unchanged. However, concentrations of inositol (Ins) relative to creatine were found to be significantly lower (P < 0.001) in the PKU patients (0.30 +/- 0.09 versus 0.57 +/- 0.17). Individual inositol concentrations did not correlate with age, diet, serum phenylalanine (Phe) levels or extent of pathological regions in the T2-weighted images. The lack of correlation with individual data suggests that the decreased inositol concentration could be related to a metabolic deficiency during fetal development. No signal from the phenyl ring protons of phenylalanine was detected in the PKU patients (phenylalanine serum concentration < or = 1.27 mM), which suggests that concentration of phenylalanine may be lower in brain than in serum.

[Echographic localization for percutaneous internal jugular vein catheterization]

The standard internal jugular vein access is an anatomical-landmark method and the individual variations causes technical difficulty and sometimes morbidity. Ultrasound guidance for percutaneous puncture of internal jugular vein is used in 20 patients for hemodialysis catheter insertion. This method allow the visualization of jugular permeability and needle progression during puncture. A control historical group comparison emphasized the advantage of this technique with lower access time (20 s vs 90 s), more first needle pass success (90% vs 50%) and reduced morbidity (carotid puncture, hematomas). The ultrasound guidance is very simple and safe but major disadvantage is the cost of the equipment.

Ondine's curse: a discussion of five cases

Five cases of central congenital hypoventilation, Ondine's curse, were studied. The diagnostic criteria were: lack of respiratory autonomy during sleep, abnormal CO2 test results and abnormal respiratory monitoring results during sleep. This hypoventilation induced chronic complications, such as a pulmonary arterial hypertension and psychomotor and/or growth retardation. The other conditions frequently associated with Ondine's curse were: brainstem disturbances, Hirschsprung disease and neuroblastoma. Since other brainstem dysfunctions are sometimes associated with hypoventilation and because complications can arise, these children routinely underwent complementary investigations. Treatment was symptomatic. Assisted mechanical ventilation was initiated as soon as possible and carefully monitored. The prognosis for these children has greatly improved and some of them lead a normal life with nightly assisted ventilation at home.

[Volumetric analysis of urinary erythrocytes in the etiological diagnosis of hematuria]

Intravenous pyelography and cystography may fail to localize the origin of haematuria. Microhaematuria is known to be present in 2 to 10 percent of the general population, usually without pathological consequences. Study of red cell morphology by phase contrast microscopy is effective in distinguishing between "glomerular" (from renal tissue) and "non-glomerular" (from urinary tract) erythrocytes, but this technique is not currently available in all laboratories. Urinary blood cell volume analysis has been presented as a simple and automatic alternative method. We compared these two techniques in 100 cases of haematuria of various origins. The cut-off point between glomerular and non-glomerular erythrocytes was set at 71 fl. Phase contrast microscopy always confirmed the clinical and/or histological diagnosis, but volume analysis did not: mean erythrocyte volume of glomerular origin was 66.6 +/- 10.4 fl, while non-glomerular volume was 94.5 +/- 17 fl (P < 0.001); cell volume analysis was confirmative in only 72 percent of all diagnoses (65 percent of microhaematurias, 83 percent of macrohaematurias); sensitivity was 65 percent and specificity 85 percent for glomerular erythrocytes. Due to poor performance, urinary red volume analysis is not an acceptable alternative method to phase contrast microscopy when searching for the site of bleeding.

[To screen or systematically treat a population at risk? A method based on the analysis of costs applicable at the level of district health]

With severely limited resources, it is necessary for the health services to select the most efficient strategy for managing health problems in a population at risk. A simple method for cost analysis, which can be used at the district health care level, is proposed so that one can choose between selective treatment on the basis of case identification, or indiscriminate treatment of the entire population at risk. The treatment of anaemia at the antenatal clinic in health centres in southwestern Chad was studied and is presented as an example. The conditions for use and the limitations of the method are discussed.