Background Arginine vasopressin (AVP), produced by
hypothalamic neurons, is released during stress following
different stimuli such as hypotension, hypoxia,
hyperosmolarity, acidosis, and infections. Measurement of
AVP levels has limitations because of its short half-life and
instability. Copeptin, the carboxy-terminal part of the
precursor (prepro-AVP), is a more stable peptide and mirrors
AVP concentrations.
Aim The aim of this work was to study the usefulness of
plasma copeptin as a predictor of prognosis and outcome of
respiratory failure patients admitted in the ICU.
Patients and methods This prospective study was carried
out on 45 patients (38 patients admitted at Benha University
Hospital ICU and Chest Department and seven healthy
patients). They were classified into three groups: group A
(ICU patients) comprised 30 patients admitted with
respiratory failure due to different chest diseases; group B (inpatients)
comprised eight patients selected from those
hospitalized at Chest Department because of respiratory
failure and with no need for ICU admission as a positive
control group; and group C comprised seven healthy patients
included as a negative control group. All patients were
submitted to full clinical history and physical examination at
ICU admission, as well as available preadmission clinical
data, pulmonary function tests, chest radiography if done,
arterial blood gases, ECG, and clinical lab data; blood
samples were taken and plasma was separated and copeptin
level was measured by sandwich immunoluminometric
assay.
Results There was a statistically significant difference among
studied groups as regards plasma copeptin level, which was
higher in ICU patients (group A) than in in-patients (group B)
and healthy control patients (group C) (P