Showing papers by "Jürgen Peters published in 1999"

Both Intravenous and Inhaled Lidocaine Attenuate Reflex Bronchoconstriction but at Different Plasma Concentrations

Abstract: Intravenous lidocaine can attenuate bronchial hyperreactivity. However, lidocaine inhalation might yield the same or better results at higher airway and lower lidocaine plasma concentrations. Therefore, we tested in awake volunteers with bronchial hyperreactivity the effect of lidocaine on histamine-induced bronchoconstriction administered either intravenously or as an aerosol. After approval of the local ethics committee, 15 volunteers were enrolled in this placebo-controlled, double-blinded, randomized study. Volunteers were selected by showing a decrease in FEV1 greater than 20% of baseline (PC20) in response to histamine inhalation. On three different days the challenge was repeated after pretreatment with either intravenous lidocaine, inhaled lidocaine, or placebo. Blood samples for determination of lidocaine plasma concentration were drawn. Comparisons were made using the Friedman and Wilcoxon signed-rank tests. Baseline PC20 was 6.4 +/- 1.1 mg. ml-1. Both inhalation of lidocaine and intravenous administration significantly increased PC20 to 14.8 +/- 3.5 mg. ml-1 and 14.2 +/- 2. 5 mg. ml-1, respectively (p = 0.0007). Peak plasma lidocaine concentrations at the end of challenges were 0.7 +/- 0.1 microg. ml-1 (inhaled) and 2.2 +/- 0.1 microg. ml-1 (i.v.). However, 7 of 15 subjects showed an initial decrease of FEV1 greater than 5% following lidocaine inhalation. While both intravenous as well as inhaled lidocaine attenuate reflex bronchoconstriction significantly, lidocaine plasma concentrations are significantly lower after inhalation. However, the high incidence of initial bronchoconstriction to lidocaine inhalation may limit its use in patients with asthma and thus offers therapeutic advantages for intravenous lidocaine.

Combined antithrombin III and C1-esterase inhibitor treatment decreases intravascular fibrin deposition and attenuates cardiorespiratory impairment in rabbits exposed to Escherichia coli endotoxin.

Abstract: Objective To assess the effect of a combined antithrombin III and C1-esterase inhibitor treatment on intravascular organ fibrin deposition and cardiorespiratory changes following intravenous Escherichia coli endotoxin (lipopolysaccharide [LPS] 80 [micro sign]g/kg iv) exposure. Design Prospective, randomized trial. Setting Research laboratory of a university medical center. Subjects Anesthetized, instrumented and mechanically ventilated rabbits ([Chbb:CH); n = 40). Interventions Endotoxin was given to 30 animals. Ten animals received no inhibitor (endotoxin control group). The other animals were either treated by high-dose (300 units/kg; n = 10) or low-dose (100 units/kg; n = 10) combined antithrombin III and C1-esterase inhibitor administration. Ten rabbits (time control group) were given placebo (sodium chloride 0.9%). Cardiorespiratory variables were assessed at baseline, 120 mins, and 240 mins after endotoxin or placebo administration. Four hours after endotoxin injection, liver, lung, and kidney tissue samples were examined for intravascular fibrin deposition by light microscopy. Measurements and Main Results Inhibitor treatment significantly decreased clot formation in lungs and livers without, however, demonstrating a clear dose-dependent effect. Combined antithrombin III/C1-esterase treatment attenuated the decrease of mean arterial pressure and cardiac output observed following endotoxin injection. Blood pressure improvement was significantly dependent on dosage administered. Conclusion Combination of antithrombin III and C1-esterase inhibitor treatment during early endotoxin shock decreased organ fibrin deposition and improved cardiovascular stability. (Crit Care Med 1999; 27:597-604)