[The effect of electrostimulation with the Rebox apparatus on ischemic renal injury in rats]. / Vliv elektrostimulátoru Rebox na prubeh ischemického poskození ledvin u krys.

BACKGROUND: With developing transplantation programmes the problem of protection against ischaemic renal damage had become important. The results of experimental pharmacological protection of the kidneys are not quite conclusive. The objective of the presented paper was to assess the effect of electrostimulation by means of a Rebox apparatus (generator of direct rectangular impulses at a frequency of 1 to 10 kHz), on the development of ischaemic damage of the renal parenchyma induced experimentally in rats. METHODS AND RESULTS: The experiments were made on Wistar strains rats (n = 15) which were subjected to dextrolateral nephrectomy and the left renal artery was closed by a clamp which was released in the tested and the control group after 30 minutes. In the rebox group electrostimulation with the Rebox apparatus was implemented immediately after release of the clamp. In rats which were in metabolic cages the following parameters were assessed: diuresis, period of survival, endogenous creatinine clearance, plasma creatinine level, urea level and excretion, as well as sodium and potassium urinary excretion. No significant difference in the survival time of the rats was found nor in the plasma levels of creatinine, urea and urinary excretion of potassium and urea between the control and the Rebox group. In the Rebox group, as compared with the control group, a significantly higher diuresis was found 22.8 vs 5.6 (p < 0.001) and natriuresis 0.44 vs 0.11 (p < 0.01). CONCLUSIONS: Electrostimulation by rebox currents in rats increases significantly the diuresis and natriuresis of the solitary kidney exposed to 30-minute ischaemia but has no impact on other parameters. The mechanism of action is not quite clear, apparently the reabsorption of sodium in the proximal tubule is inhibited.

Shifts in external iliac venous pressure under local and general anaesthesia. Their impact on the tactics of venous thrombectomy in iliofemoral thrombosis.

The authors measured the venous pressure in the iliofemoral segment in 12 patients in good general conditions, with a normal patency of the inferior caval vein, profound pelvic veins, and lower limb veins. Examination was performed with Claudy manometer. The resting venous pressure in the external iliac vein was 40--75 mm H2O = 3--5.5 mmHg. During Valsalva's manoeuvre the patients achieved an overpressure 250--1 100 mm H2O = 18--81 mmHg for 20 s. After induction of general anaesthesia and intubation, the anaesthesiologist produced an overpressure of 50 cm H2O in the patient's respiratory circuit for 20 s, but the venous pressure rose only to 90--175 mm H2O = 7-- mmHg. This rise is lesser with a high statistical significance than the overpressure produced in the Valsalva's manoeuvre. In the light of these results the authors discuss the tactics of venous thrombectomy. As a safe prevention of peroperative uplmonary embolism they regard either Valsalva's manoeuvre, carried out under local anaesthesia, or a tourniquet fixation of the clot head during the surgical intervention under general anaesthesia. The anaesthesiologist cannot prevent embolism by restriction of the venous return by producing an overpressure in the respiratory circuit of a patient under general anaesthesia.