Effect of excitatory amino acid receptor blocker MK-801 on overall, neurologic, and morphologic outcome after prolonged cardiac arrest in dogs

Excitatory amino acids accumulating in the brain during ischemia may cause selective neuronal damage postischemia. This hypothesis was tested in a series of studies using MK-801, an N-methyl-D-aspartate (NMDA) receptor blocker, in a reproducible outcome model of prolonged cardiac arrest in dogs. After normothermic ventricular fibrillation cardiac arrest, the dogs were resuscitated with closed-chest femoral veno-arterial cardiopulmonary bypass. At 4 h they were separated from bypass, ventilation was controlled for 20 h, and intensive care was continued to 96 h. In Study I, ventricular fibrilation cardiac arrest (no-flow) was 17 min; starting immediately with reperfusion, MK-801 1200 mg/kg (n = 5) or an equal volume of placebo (n = 5) was infused over 12 h in blinded, randomized fashion. In Study II, the duration of the no-flow period was reduced to 15 min, and MK-801 2400 mg.kg-1 (n = 4) or placebo (n = 4) was infused. In Study III, no-flow lasted for 15 min, and MK-801 2400 mg/kg was started 30 min before ventricular fibrillation (n = 4); comparison was with Study II controls. In all three studies, MK-801 plasma concentrations peaked at greater than 50 ng/ml and were 15-30 ng/ml over 12 h. All 22 dogs of experiments within protocol survived with severe brain damage. MK-801 delayed return of pupillary reactivity, EEG activity, consciousness, and respiration, necessitating longer periods of controlled ventilation. Neurologic deficit scores, overall performance categories, and brain and heart morphologic damage scores at 96 h did not differ between placebo and MK-801 pretreatment or post-treatment groups. These negative outcome results after prolonged cardiac arrest do not negate the hyperexcitability hypothesis of selective vulnerability, but suggest the existance of additional mechanisms of secondary brain damage.

[Trimethoprim as a monosubstance and cotrimoxazole in infections of the efferent urinary tract]

In a randomized single blind study the efficiency of Trimethoprim as a monosubstance used in the therapy of urinary tract infections was compared to that of Cotrimoxazole. There was a total of 40 patients available 20 of whom were given 2 X 200 mg Trimethoprim throughout 10 days whereas the other 20 patients were given 2 X 160 mg Trimethoprim + 800 mg Sulphamethoxazole in the same period. All patients were hospitalized during treatment. The urine was bacteriologically checked at the beginning of the treatment and after 7, 14 and 28 days respectively. The therapy was equally successful in both groups, both from the clinical and the bacteriological point of view (Trimethoprim 17, Cotrimoxazole 18); a statistically significant difference was not to be proved. In the Trimethoprim group there was one relapse, in the Cotrimoxazole group there were two. Undesirable side effects occurred in both groups with a larger number of them occurring in the Cotrimoxazole group. Cotrimoxazole and Trimethoprim proved equally efficient from a clinical point of view. The proportion of side effects is more favourable for Trimethoprim alone; the cost of therapy is almost 50% lower than that of Cotrimoxazole.

[Pharmacologic modification of diastolic ventricular function in patients with coronary heart disease]

The influence of 2 different cardiac pharmaceutics on the diastolic ventricular function (VF) in patients with ischaemic heart disease was examined. Diltiazem, a calcium antagonist, and k-strophanthine led to a reduction of time constant T of the isovolumic relaxation from 49 +/- 9 to 39 +/- 7 msec (p less than 0.005), to an increase of the quotient dt/T from 2.4 +/- 0.5 to 3.0 +/- 0.6 msec (p less than 0.01), to an increase of the peak filling rate (PFR) from 2.08 +/- 0.65 EDV/sec to 2.34 +/- 0.67 EDV/sec (p less than 0.001), to an increase of the filling fraction (FF) from 30 +/- 12% to 33 +/- 15% (p less than 0.001). The ejection fraction (EF) and the maximum rise of pressure dp/dt did not change significantly. After k-strophanthine T was reduced from 49 +/- 7 to 46 +/- 11 msec (p less than 0.05). The increase of dt/T from 2.5 +/- 0.4 to 2.7 +/- 0.4 msec was not significant. The PFR with 2.16 +/- 0.7 and 2.08 +/- 0.8 EDV/sec and the FF with 32 +/- 14 and 34 +/- 18% did not show any significant changes. The EF rose from 52 +/- 15 to 55 +/- 16 (p less than 0.05) and dp/dt rose from 1855 +/- 468 to 2124 +/- 591 (p less than 0.05). Diltiazem improves the diastolic VF without deteriorating the systolic VF in patients with ischaemic heart disease. K-strophanthine improves the systolic VF and the velocity of the isovolumic relaxation. The other variables of the diastolic VF did not show any directed changes.

[Acute kidney failure]

The etiology of acute renal failure is quite complex, in contradistinction to the monotonous appearance of the corresponding renal pathomorphology (tubular necrosis, intracapillary coagulation). A basic prerequisite for the successful prevention of acute renal failure is the knowledge of the responsible atiopathogenetic factors and their early recognition. Once kidney damage has occurred, therapeutic measures shift to concentrate on the symptomatic treatment of renal failure and the prevention of accompanying complications such as a hemorrhagic tendency, susceptibility to infections, hyperkalemia, hyperhydration, catabolism etc. In addition to the proper choice of the detoxification procedure (hemodialysis, hemofiltration, peritoneal dialysis, continuous a.v. hemofiltration) precise fluid and electrolyte balance, optimal nutrition, and the adjustment of drug dosages to the degree of renal insufficiency all play an important rule. The therapeutic principles and the differential therapy of the various detoxification procedures are discussed on the basis of concrete recommendations.

[Endogenous creatinine clearing during cytostatic therapy]

25 patients with a malign neoplasia were treated with cytostatics. The endogenous creatinine clearance as a parameter of the kidney function was checked. Patients who had no side-effects, did not show important changes in kidney function immediately and 10 days after the treatment. Patients who had hyperemesis and diarrhoea showed an impairment, patients with a hyperkinetic reaction improvement of kidney function. General hyperhydration during a cytostatic treatment is not necessary, it can even be dangerous for patients with a hyperkinetic reaction.