[Practical methods for controlled diaphragmatic breathing in 2009: proposals for a consensus]. / Modalités pratiques de réalisation de la ventilation dirigée abdomino-diaphragmatique en 2009: propositions pour un consensus.

BACKGROUND: This work has been completed at the request of the French Language Society of Pneumology. It is the result of collaboration between the 'Muscles and Respiration Group' and the 'Working Group in Physiotherapy', arriving at a consensus on diaphragmatic breathing. RESULTS: From the literature followed by a formalized consensus methodology, the authors specify the terminology and define the appropriate methods of this technique that should be used. CONCLUSION: Analysis of the literature to date does not allow assessment of the efficacy of this technique. The precise definition of the methods of diaphragmatic breathing as proposed in the present study will be used as a basis for forthcoming studies on this technique.

Concurrent high-performance liquid chromatographic measurement of loxapine and amoxapine and of their hydroxylated metabolites in plasma.

The dibenzoxazepine neuroleptic loxapine, its N-demethylated metabolite amoxapine, and their 7- and 8-hydroxymetabolites were measured simultaneously in plasma by reversed-phase high-performance chromatographic method. An original liquid-liquid extraction procedure was performed, consisting in coextraction of the substances together with a water-miscible solvent (acetonitrile) by a non-water-miscible solvent (toluene). The substances were separated on a 5-microm CN 25-cm column, and eluted with a mobile phase consisting of acetonitrile-acetic acid 0.5 N (30:70) and hexylamine (0.05%). They were detected by ultraviolet spectrophotometry at 310 nm. Clozapine was used as internal standard. Linearity was demonstrated in the range of 10 to 250 microg/l, and detection limits were found to be 3.5 to 6.3 microg/l according to the substance. Within-day repeatability ranged from 2.7% to 6.5%, and between-day reproducibility ranged from 0.9% to 20.2%. The extraction procedure provided a mean absolute recovery of 51.1% (range, 40.7% to 58.6%) with a mean coefficient of variation of 4.2%. This technique was applied to the concurrent determination of plasma concentrations of the compounds in 10 patients administered loxapine 75 to 600 mg daily. Steady state plasma levels of loxapine were significantly correlated with oral doses (n = 10, r = 0.858, p < 0.002). In conclusion, the method proved to be a convenient and reproducible procedure allowing the simultaneous measurement of loxapine, amoxapine, and their metabolites in patients.