The aim of the study is to measure serum levels of myristic acid in septic patients and to compare them with myristic acid serum levels in patients with Systemic Inflammatory Response Syndrome of non infective etiology and in healthy volunteers. Furthermore, other biomarkers of sepsis are evaluated in comparison with microbiological findings detected either by standard hemocultures or by molecular biological methods.

Currently, there is an array of biomarkers potentially useful in diagnosis and prognosis in septic patients, either alone or in combination. Only a fraction of them is used in clinical practice. The reasons vary, low sensitivity or specificity is the main one, cost/benefit or difficult processing with the need of highly specialized laboratory to name the other.

Recent pilot study from Swedish authors (A.M.Kauppi et al.) published in 2016 showed high correlation of myristic acid levels in blood in patients with sepsis and bacteraemia. There was no other publication on this molecule in relation to sepsis before. Cambiaghi et al. observed its significant decrease in nonresponders to the treatment of septic shock.

Myristic acid is an organic acid of linear structure. Measurement of its level will be performed using gas chromatography linked with mass spectrometry.

Inclusion Criteria:

• Sepsis or septic shock.
• Systemic inflammatory response syndrome.
• Subjects without systemic inflammation.

Exclusion Criteria:

• There is no exclusion criteria in the study

Patients admitted to ICU in study group, patients with Systemic Inflammatory Response Syndrome after surgery in SIRS group and subjects without systemic inflammation in control group.