[Comparison of the antithrombotic effects of heparin, enoxaparin and prostacycline in continuous hemofiltration]. / Comparaison des effets antithrombotiques de l'héparine, l'énoxaparine et la prostacycline au cours de l'hémofiltration continue.

Continuous anticoagulation is required during haemofiltration to prevent the deposition of fibrin and the formation of thrombus which would lead to early clotting of the haemofilter. This study aimed to compare the efficiencies of 3 different anticoagulation protocol: 150 IU.kg-1.day-1 heparin (group HEP), 1.2 mg.kg-1.day-1 enoxaparin (group ENX), and a combination of 0.8 mg.kg-1.day-1 enoxaparin with 5 ng.kg-1.min-1 prostaglandin I2 (group ENX and PGI2). A flat ANS69S (Hospal) haemofilter was used for continuous venovenous haemofiltration. Antithrombotic efficiency was assessed with a haemofilter permeability index (HPI) including the transmembraneous pressure gradient and the rate of production of ultrafiltrate. The time required for HPI to decrease to 1/3 of its initial value (HPI1/3) was used to compare the 3 protocols. Treatment tolerance was judged by monitoring the usual haemodynamic and haemostatic parameters. No adverse effects (bleeding, thrombosis, hypotension) were observed. HPI1/3 was 15.1 +/- 2.4 h, 18.3 +/- 3.1 h and 28.2 +/- 4.2 h in groups HEP, ENX and ENX and PGI2 respectively. High dose enoxaparin reached antithrombotic efficiency without increasing the risk of haemorrhage. The use of low doses of prostaglandin I2 greatly increased HPI1/3, without any deleterious haemodynamic effects. However, the high cost of prostaglandin I2 needs to be put in the balance with the increase in duration of haemofilter life. Therefore, further investigations are required to evaluate the possible synergy between heparin and prostaglandin I2, as well as the biological parameters which need to be monitored.

[Criteria for choice of an anesthetic technic for laryngeal laser microsurgery using the laser in adults]. / Critères de choix d'une technique anesthésique pour la micro-chirurgie laryngée au laser de l'adulte.

Laryngeal microsurgery by means of the laser involves anesthetic constraints regarding mainly the mode of ventilation during operation. The principal techniques and different anesthetic protocols are discussed. The two main criteria for the choice of method appear to be the permeability of the laryngeal passage and the patient's general condition and history. The two principal methods proposed are high frequency jet ventilation and ventilation controlled by a protected intubation tube.

[Partial pharyngo-laryngectomy with subtotal esophagectomy and 1-stage coloplasty]. / Pharyngo-laryngectomie partielle avec oesophagectomie sub-totale et coloplastie en un temps.

A patient with cancer of both the hypopharynx and esophagus was treated by partial pharyngolaryngectomy, subtotal esophagectomy and a reconstructive one-stage coloplasty. Surgical and carcinologic problems raised by this technique are discussed.

[Effects of anesthesia induction with propofol on plasma renin activity and atrial natriuretic factor secretion. A preliminary study]. / Effets de l'induction anesthésique au propofol sur l'activité rénine plasmatique (ARP) et la sécrétion de facteur natriurétique auriculaire (ANF). Etude préliminaire.

The authors have noted a substantial increase in plasma renin activity, when the patients were induced with propofol (2.5 mg.kg-1). Although a direct or an indirect effect of propofol may be suggested, the design of this study is not helpful in pointing out the responsibility of the drug in the observed effects. Further studies including peripheral vascular resistance measurements should be undertaken.

[Determination of elimination of pefloxacin and of its derivatives in continuous hemodiafiltration]. / Détermination de l'élimination de la péfloxacine et de ses dérivés en hémodiafiltration continue.

Continuous venovenous hemofiltration with dialysis (CVVHD) is being increasingly used to treat acute renal failure. However, because of the-lack of data on the clearance of therapeutic agents during this treatment, there is a risk of using inappropriate dosages. This in vitro study was undertaken to determine the clearance of pefloxacin (P) and its two main metabolites (active N-desmethyl P and inactive N-oxide P) during CVVHD. Acitrate-dextrose (ACD) anticoagulated fresh human blood containing P and its two metabolites in the usual therapeutic levels was circulated at a rate of 100 ml min.-1 through a closed-circuit continuous venovenous hemofiltration with dialysis unit (BSM 22-Hospal hemofilter). Temperature and ionic composition of the blood were controlled. Dialysate (L2D, Hospal) was circulated on the other side of the continuous venovenous hemofiltration with dialysis membrane at three different flow rates (Qdi) (0, 500 and 1,000 ml.h-1. The dialysate/ultrafiltrate outflow was adjusted using a withdrawal pump to obtain nul ultrafiltration. Arterial blood, venous blood and ultrafiltrate were sampled simultaneously at different time points for High Performance Liquid Chromatography (HPLC) assays and determination of the clearances (Cl) and sieving coefficients (s) of each compound. Pefloxacin had a sieving coefficient of 0.42 and a clearance of 6.8 ml min-1 when Qdi was nul. With the blood flow used, clearances were found to be correlated with the dialysate flow rate; when this rate was 500 ml h-1, a pefloxacin clearance similar to that seen in healthy subjects was obtained (15.2 ml min-1). The two bacteriologically active forms of the drug (pefloxacin and N-desmethyl P) had similar elimination parameters.(ABSTRACT TRUNCATED AT 250 WORDS)