Copeptin and arginine vasopressin concentrations in critically ill patients.
BACKGROUND
Determination of arginine vasopressin (AVP) concentrations may be helpful to guide therapy in critically ill patients. A new assay analyzing copeptin, a stable peptide derived from the AVP precursor, has been introduced.


OBJECTIVE
Our objective was to determine plasma copeptin concentrations.


METHODS
We conducted a post hoc analysis of plasma samples and data from a prospective study.


METHODS
The setting was a 12-bed general and surgical intensive care unit (ICU) in a tertiary university teaching hospital.


METHODS
Our subjects were 70 healthy volunteers and 157 ICU patients with sepsis, with systemic inflammatory response syndrome (SIRS), and after cardiac surgery.


METHODS
There were no interventions.


METHODS
Copeptin plasma concentrations, demographic data, AVP plasma concentrations, and a multiple organ dysfunction syndrome score were documented 24 h after ICU admission.


RESULTS
AVP (P < 0.001) and copeptin (P < 0.001) concentrations were significantly higher in ICU patients than in controls. Patients after cardiac surgery had higher AVP (P = 0.003) and copeptin (P = 0.003) concentrations than patients with sepsis or SIRS. Independent of critical illness, copeptin and AVP correlated highly significantly with each other. Critically ill patients with sepsis and SIRS exhibited a significantly higher ratio of copeptin/AVP plasma concentrations than patients after cardiac surgery (P = 0.012). The American Society of Anesthesiologists' classification (P = 0.046) and C-reactive protein concentrations (P = 0.006) were significantly correlated with the copeptin/AVP ratio.


CONCLUSIONS
Plasma concentrations of copeptin and AVP in healthy volunteers and critically ill patients correlate significantly with each other. The ratio of copeptin/AVP plasma concentrations is increased in patients with sepsis and SIRS, suggesting that copeptin may overestimate AVP plasma concentrations in these patients.
Jochberger
Stefan
S
Department of Anesthesiology, Innsbruck Medical University, Anichstrasse 35, 6020 Innsbruck, Austria. Stefan.Jochberger@uibk.ac.at
Morgenthaler
Nils G
NG
Mayr
Viktoria D
VD
Luckner
Günter
G
Wenzel
Volker
V
Ulmer
Hanno
H
Schwarz
Siegfried
S
Hasibeder
Walter R
WR
Friesenecker
Barbara E
BE
Dünser
Martin W
MW
D000328:Adult; D000368:Aged; D001127:Arginine Vasopressin / Q000097:blood*; D002097:C-Reactive Protein / Q000032:analysis; D016022:Case-Control Studies; D016638:Critical Illness; D005260:Female; D006020:Glycopeptides / Q000097:blood*; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care; D018805:Sepsis / Q000097:blood; D018746:Systemic Inflammatory Response Syndrome / Q000097:blood; D013903:Thoracic Surgery
D006020:Glycopeptides; C048197:copeptins; D001127:Arginine Vasopressin; D002097:C-Reactive Protein