CHIC study's purpose is to compare the efficiency, in terms of blood pressure stability, of three changeovers of norepinephrine used routinely in ICU. The three techniques are:

• Quick change
• Double pumping
• Smart infusion pumps

The drugs used in intensive care units are numerous and their administration is based on a strong expertise in this context of urgency and complexity. Nurses role is not only to carry out preparation of a treatment but to implement a complex treatment that requires a risk management approach surpassing the simple task to which the decree of professional acts refers to.

In this context, the administration of catecholamines, widely used in intensive care medicine in the treatment of shock, appears to be a sensitive issue to study. These vasoactive drugs have a short half-life and a narrow therapeutic index. Administration should be careful ensuring both efficiency and prevention of complications such as hemodynamic instability or arrhythmias.

Administration of these therapeutic must be strictly continuous, that is to say delivered using electric syringe pumps. Syringe replacements appear as critical moments because of the risk of flow change or brief interruption of the infusion.

There are three main types of syringes relay techniques, but to date, no study has compared these techniques with each other. There is thus no recommendation based on objective datas to guide clinical nursing practice.

This study aims to provide evidence in order to secure the administration of catecholamines. It may also use as a reference for evaluation of new features that allow automation relays with called "smart pumps" and for which no study has demonstrated the added value in terms of security. No progress will be possible in securing the administration of drugs with a short half-life, narrow therapeutic index and significant side effects without a deep reflection of the conditions of their infusion. The choice of materials used and the development of care procedures must be based on reliable and timely recommendations. Patients expect safer care. Nurses must be able to have references enabling them to guide their practice to the benefit of patients.

Inclusion Criteria:

• Admission in Intensive Care Unit
• Norepinephrine perfusion started for less than three hours in ICU
• Invasive monitoring of blood pressure

Exclusion Criteria:

• Age under 18
• Pregnant and breastfeeding women
• Previous participation in the trial
• No registration in any health care system
• Patient protected by law
• Patient study refusal
• Active therapeutic limitation decision