[The effects of incremental PEEP on atrial natriuretic peptide, right atrial pressure and the size of the right atrium in anesthetized patients].
8 ASA class II-III patients (50-67 years) undergoing traumatic-surgical procedures were studied. Since the release of atrial natriuretic peptide (ANP) is stimulated by volume loading and increased right atrial pressure (RAP), the effects of incremental positive end-expiratory pressure (PEEP) on ANP-concentration, RAP and right atrial dimensions were investigated. Anaesthesia was induced with intravenous etomidate and vecuronium and maintained after endotracheal intubation with 66% N2O in O2 and ethrane (0.4-0.6 Vol.-%). A catheter was inserted into the A. radialis for blood sampling and determination of mean arterial pressure (MAP). For determining endsystolic (RAESA) and end-diastolic (RAEDA) areas of the right atrium a 5 MHz transoesophageal echocardiographic (TEE)-probe was positioned at the level of the foramen ovale. Under TEE-control a catheter was placed into the right atrium for measurement of RAP. The method for ANP determination was based on a direct radioimmunoassay that is specific for human ANP (ANP-J125). PEEP was incrementally raised from 0 to 16 mbar in 4 mbar steps each for 5 min and thereafter reduced to 0 mbar. During the investigation no significant differences were detectable for MAP, heart rate, end-expiratory CO2 partial pressure and the arterial O2 saturation. However, 16 mbar PEEP ventilation increased plasma ANP concentrations (from 44.3 +/- 9.7 to 58.1 +/- 8.7 pg/ml) and RAP (from 4.4 +/- 0.9 to 10.7 +/- 0.9 mmHg) whereas the right atrial dimensions RAESA (from 9.4 +/- 1.0 to 4.6 +/- 0.6 cm2) and RAEDA (from 5.9 +/- 1.2 to 3.2 +/- 0.4 cm2) decreased.(ABSTRACT TRUNCATED AT 250 WORDS)
Scholz
J
J
Abteilung für Anästhesiologie, Universitäts-Krankenhaus Eppendorf, Hamburg.
Bednarz
F
F
Roewer
N
N
Schmidt
R
R
Schulte am Esch
J
J
D000368:Aged; D000769:Anesthesia, Inhalation; D009320:Atrial Natriuretic Factor / Q000097:blood*; D004737:Enflurane; D006321:Heart / Q000503:physiopathology*; D006801:Humans; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D009609:Nitrous Oxide; D010100:Oxygen; D011175:Positive-Pressure Respiration
D009320:Atrial Natriuretic Factor; D004737:Enflurane; D009609:Nitrous Oxide; D010100:Oxygen
Wirkungen steigender PEEP-Stufen auf das atriale natriuretische Peptid, den rechtsatrialen Druck und die Grösse des rechten Vorhofes bei narkotisierten Patienten.