title: ACE inhibition facilitates sodium and water excretion during PEEP in conscious volume-expanded dogs.
abstract: Increased activity of the renin-angiotensin system may be involved in sodium and water retention during controlled mechanical ventilation (CMV) with positive end-expiratory pressure (PEEP). We therefore evaluated renal, hemodynamic, and hormonal effects of an acute angiotensin-converting enzyme inhibition (ACEI) during PEEP and extracellular volume expansion in five trained chronically tracheotomized dogs. Three protocols were performed: control, 4 h spontaneous breathing with continuous positive mean airway pressure (Paw) of 4 cmH2O (CPAP 4); CMV 20, CPAP for 1st h, CMV with 20 cmH2O Paw for 2 h (2nd and 3rd h), and 1 h of CPAP (4th h); and CMV20-ACEI, ACEI (Ramipril, 2 mg/kg body wt) followed by the same protocol as in CMV 20. During control, sodium excretion (UNaV) and urine volume (V) increased continuously to 56.2 +/- 2.7 (SE) mumol.min-1.kg body wt-1 and 482 +/- 23 microliters.min-1.kg body wt-1, respectively. UNaV and V increased less during PEEP in CMV 20 and CMV 20-ACEI. However, significantly more sodium and water were retained in CMV 20 than in CMV 20-ACEI (2.3 +/- 0.3 vs. 1.0 +/- 0.3 mmol/kg body wt, and 20 +/- 3 vs. 11 +/- 2 ml/kg body wt) because of a decrease of glomerular filtration rate and fractional UNaV in CMV 20. Heart rate did not change in control, CMV 20, or CMV 20-ACEI. Mean arterial pressure increased during control by 13 mmHg, did not change during CMV 20, and was decreased by 7 mmHg in CMV 20-ACEI.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Clinic of Anesthesiology and Operative Intensive Medicine, Universitätsklinikum Rudolf Virchow Standort Charlottenburg, Free University of Berlin, Federal Republic of Germany.
authors.forename: G
authors.initials: G
authors.lastname: Kaczmarczyk
authors.forename: R
authors.initials: R
authors.lastname: Rossaint
authors.forename: C
authors.initials: C
authors.lastname: Altmann
authors.forename: K
authors.initials: K
authors.lastname: Falke
authors.forename: R
authors.initials: R
authors.lastname: Mohnhaupt
authors.forename: H W
authors.initials: HW
authors.lastname: Reinhardt
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D004231:Diuresis / Q000187:drug effects* / Q000502:physiology; D004285:Dogs; D005110:Extracellular Space / Q000187:drug effects / Q000502:physiology; D005260:Female; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D009318:Natriuresis / Q000187:drug effects* / Q000502:physiology; D011175:Positive-Pressure Respiration / Q000009:adverse effects*; D012084:Renin-Angiotensin System / Q000187:drug effects / Q000502:physiology; D014882:Water-Electrolyte Balance / Q000187:drug effects / Q000502:physiology
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors