The kinetics of metamizol and its metabolites in critical-care patients with acute renal dysfunction.

We have studied the clearance of monomethylaminoantipyrine (MMAAP), the pharmacologically active form of metamizol, in 46 patients in surgical intensive care with different degrees of renal dysfunction. In 23 patients without any renal impairment, mean clearance was 2.8 ml.min-1 x kg-1. Twenty-one patients with acute renal impairment had a significantly reduced clearance of MMAAP (0.83 ml.min-1 x kg-1). There was also reduced clearance in four patients with septic shock (1.0 ml.min-1 x kg-1). Kinetics of the metabolites of MMAAP (N-formylaminoantipyrine (FAAP), aminoantipyrine (AAP), and its secondary product N-acetylaminoantipyrine (AcAAP)) were calculated. FAAP and AcAAP showed delayed invasion, which can be explained by reduced hepatic metabolic activity. The product of N-demethylation, AAP, was not significantly altered. The delayed elimination of monomethylaminoantipyrine can be explained by reduced hepatic function in parallel with acute renal failure due to disturbed cardiovascular function caused by septic shock. This may also lead to disturbed hepatic macro- and microperfusion associated with altered oxygen supply and oxygen consumption.

Kinetics of hexobarbital and dipyrone in critical care patients receiving high-dose pentobarbital.

The effect of pentobarbital treatment in a mean dose of 30 mg/kg/day on the clearance of hexobarbital (Evipan) and dipyrone (Novalgin) has been evaluated in critical care patients receiving a large number of drugs as comedication. Eleven patients treated with pentobarbital showed a hexobarbital half-life of 2.79 h and a total plasma clearance of 9.80 ml X min-1 X kg-1 as compared to 10 patients without pentobarbital administration in whom there was a significantly longer half life (6.92 h) and lower clearance (2.97 ml X min-1 X kg-1). The kinetics of hexobarbital were correlated with the urinary excretion of D-glucaric acid, a non-invasive parameter of drug metabolising activity. In 10 patients on pentobarbital, the total plasma clearance of N-4-methyl-aminoantipyrine, the active form of dipyrone, did not differ from that in 8 patients not receiving pentobarbital. As drug kinetics show great variability in these patients, it is difficult to discriminate enzyme induction from other mechanisms, for example competitive inhibition or changes in volume of distribution. In the presence of pentobarbital, however, induction of drug metabolising enzymes should be considered as a possible reason for the higher clearance of hexobarbital.

[Respiratory controlled intermittent inspiratory pleural drainage--a method for handling life threatening bronchopleural fistulas]. / Die respiratorgesteuerte intermittierende Pleuradrainage--eine Methode zur Behandlung lebensbedrohlicher bronchopleuraler Fisteln.

A report is presented on a technical device for artificial ventilation of patients with severe bronchopleural fistulae. The respirator-controlled apparatus interrupts drainage suction at the beginning of inspiration and releases it again at expiration. In contrast to similar constructions, this system does not allow drainage secretions to influence its functional efficiency. Modifications for connection of this apparatus are conceivable for all modern respirators. A case is described in order to demonstrate the effectiveness of the procedure. The hitherto published literature is critically reviewed.

[Fatal burn from a heated mat on the operating table]. / Tödliche Verbrennungen durch Operationstischheizmatte.

A number of heating mats were developed for use on operating tables in order to avoid hypothermia and incidental cardiocirculatory changes in patients undergoing prolonged surgical interventions. Because of inadequate technical safety devices, they can cause burns in patients. We report the case of a patient who, undergoing surgery for an aortobifemoral bypass, died of 2nd and 3rd degree burns after having been placed on a Maquet mat. Other possibilities which may lead to such severe burns are discussed.