Rocuronium is a non-depolarising neuromuscular blocking agent. The compound has a rapid onset and an intermediate duration of action.

The rapid onset is of importance in patients at risk for pulmonary aspiration, for elective induction of anesthesia. Clinical studies simulating rapid sequence induction in elective patients indicate that rocuronium 0.9 mg kg-1 may be suitable for crash intubation.Also, rocuronium may be an alternative to succinylcholine for rapid sequence induction when high dose is injected (3x Effective Dose 95 %= 1mg/kg). But, pharmacokinetic of rocuronium at 1 mg/kg is not well establish.

The investigator investigate the onset and recovery of a single dose rocuronium (1 mg/kg) in consecutive patients (>100) using adductor muscle monitoring (Train of Four and Post Tetanic Count)

In this study, pharmacokinetic of rocuronium at 1 mg/kg will be evaluated at each point of Train of Four Response (TOF) and Post Tetanic Count (when TOF=0) troughout the period of anesthesia and surgery.

Time 0 is the time of rocuronium injection, Time 1 is the time when post tetanic count is > 5-7 and TOF=0, Time 3 when TOF >0 response, Time 4 when 4 reponses of the TOF and Time 5 when TOF > 90 %

Inclusion Criteria:

• elective or emergency surgery under general anesthesia with deep block
• approval
• adult

Exclusion Criteria:

• contra indication to neuromuscular blockade (allergy, myopathy, hyperkaliemia)
• refusal
• < 18 years olds
• Body mass index > 50
• neuropathy
• regional anesthesia

Patients scheduled for surgery under general anesthesia with the need of deep neuromuscular block for surgery