Severe sepsis and septic shocks are increasingly codified. A biomarker as Lactate is very interesting to detect those situations. Usually, lactate used is arterial but results are often too slow to obtain if we want to respect Surviving Sepsis Campaign guidelines. Some analyzers (EKF diagnostics Lactate Scout*) can give results in 15 seconds.

We hypothesized that capillary lactate, easy to sample, tested with this analyzer may detect earlier those infections states and we want to find the most accurate site to detect severe sepsis (capillary, venous or arterial sample).

Actually, patients presenting a sepsis with arterial lactate> 2 mmol.l-1 must be considered as criticals, and if lactate> 4 mmol.l-1 as septic shock. However, results are usually slow to obtain, especially if we want to respect the Surving Sepsis Campaign, which preconize antibiotic as soon as possible (first hour).

In admission room, arterial sample can't be easily done and usual results need more than 30 minutes. On the contrary, using analyzers like "EKF diagnostics Lactate Scout*" can give results faster with capillary blood (15 seconds). We will compare this results with both veinous and arterial lactate.

• For primary outcome, we will determine the most accurate value of capillary or veinous lactate that may be able to detect critical patient suspected of infection.
• for secondary outcomes, we will determine if quick capillary lactate test may replace arterial lactate in this indication and be able to predict mortality.

Inclusion Criteria:

• Age >18 years
• S.I.R.S : 2 or more criteria (fever > 38.3°C or hypothermia (core temperature < 36°C) heart rate > 90.min-1, tachypnea, altered mental status)
• Suspected infection

Exclusion Criteria:

• Arterial sample by laboratory reference method no available

Patients with suspected infection in emergency department (admission time)