ORIGINAL ARTICLES   

International Angiology 2004 June;23(2):177-84

Copyright © 2004 EDIZIONI MINERVA MEDICA

lingua: Inglese

Modifications of plasma concentrations of hormonal and tissue factors during mechanical ventilation with positive end-expiratory pressure

Barbieri A. ¹, Siniscalchi A. ², De Pietri L. ², Pasetto A. ², Torsello A. ³, Nolli M. ⁴

¹ Department of Emergency, University of Modena and Reggio Emilia, Policlinico, Modena, Italy 2 Department of General Surgery and Surgical Specialities, University of Modena and Reggio Emilia, Policlinico, Modena, Italy 3 Department of Experimental Medicine, Environmental and Medical Biotechnologies, University of Milano-Bicocca, Monza (Milan), Italy 4 Intensive Care Unit, S. Andrea Hospital, La Spezia, Italy

Aim. The aim of this study is to ana­lyse if the ­decrease of car­diac per­for­mance due to pos­i­tive end-expir­a­to­ry pres­sure (PEEP) appli­ca­tion, with­in low val­ues ­applied in clin­i­cal prac­tice (5 cm H2O) is able to trig­ger a ­response of the main endog­e­nous fac­tors which con­trol and main­tain the mean arte­ri­al pres­sure (MAP).
Meth­ods. This study was ­applied to 18 ­patients, admit­ted to the Inten­sive Care Unit (ICU) of the Uni­ver­sity Hos­pi­tal of Mod­ena, who under­went oro-tra­cheal intu­ba­tion and mechan­i­cal ven­ti­la­tion. On admis­sion, ­patients did not suf­fer from car­diac or lung dis­ease. This study anal­y­ses plas­ma con­cen­tra­tions of epi­neph­rine, nor­epi­neph­rine, ET-1, NO metab­olites, renin, aldos­te­rone at 4 dif­fer­ent times: ­before PEEP appli­ca­tion, 60 min­utes after the begin­ning of mechan­i­cal ven­ti­la­tion with PEEP, and respec­tive­ly 30 and 60 min­utes after with­draw­al of PEEP. At the same time, MAP val­ues and heart rate (HR) have been ­observed.
­Results. ­Results show an ­increase of epi­neph­rine and nor­epi­neph­rine after PEEP appli­ca­tion and a ­decrease to basal val­ues at PEEP with­draw­al. All vari­a­tions are sta­tis­ti­cal­ly sig­nif­i­cant. After PEEP intro­duc­tion, ET-1 ­showed an ­increased con­cen­tra­tion, ­although it was not sta­tis­ti­cal­ly sig­nif­i­cant, while a sig­nif­i­cant decreas­ing trend was ­observed after PEEP with­draw­al. A sig­nif­i­cant ­increase of NO metab­olite val­ues has been ­observed togeth­er with the ­increase of ET-1, fol­lowed by a ­decrease to basal val­ues after the with­draw­al of PEEP. Con­cen­tra­tions of renin ­increased when PEEP was ­applied even ­though they were not sig­nif­i­cant and ­decreased sig­nif­i­cant­ly when PEEP was with­drawn. A sim­i­lar trend was ­revealed by aldos­te­rone even ­though it under­went con­stant sig­nif­i­cant vari­a­tions.
Con­clu­sion. The admin­is­tra­tion of PEEP pro­duc­es an effec­tive ­response of endog­e­nous sub­stanc­es whose func­tion is to main­tain a prop­er tis­sue per­fu­sion.