Upregulation of Alpha-1 Receptors Upon Septic Shock? (CATACHOC)

Inclusion Criteria:

• patients presenting to the CCU with septic shock : SBP<90 mm Hg refractory to volume load (>30 ml.kg-1 within 6 h before inclusion) thus in need administration of noradrenaline for >1 h (0.1 mcg.kg-1.h-1 i.e. >0.5 mg.h-1/70 kg) to maintain mean BP>65 mm Hg.
• criteria for sepsis :temperature>38.5 or <36°C ; WBC>12 000 or <4000/ml ; tachypnea (>20 cycles par min) or mechanical ventilation ; tachycardia : >90 bpmin
• written informed consent by the patient or next of kin or signature by the investigators of the form "emergency inclusion"

Exclusion Criteria:

• age<18 ans
• pregnancy
• mental illness making informed consent impossible
• Absence of consent as signed by the patient or next of kin or signature of "emergency inclusion form"
• individual without social security coverage or participating in another biomedical research
• Contre-indications to clonidine (uncorrected hypovolemia, sick sinus syndrom, III grade AV block)
• HR<70 bp/min
• pre-exitus