Pain evaluation remains a clinical problem. Pain Monitor allows pain evaluation using the measurement of skin conductance.

Withdrawal of chest tube can be painful and the purpose of the study was to compare auto-evaluation of pain (visual analogic scale) and the index measured by the Pain Monitor.

Inclusion Criteria:

• patients undergoing removal of a chest tube after lung surgery,
• patients able to indicate the pain score.

Exclusion Criteria:

• pregnancy, lactation ,
• insulin-dependent diabetes with dysautonomia,
• central or peripheral neurological disease, agitation,
• inability to understand the protocol,
• inability to use the Pain Monitor: skin abnormalities at the site of measurement, pacemaker or implantable defibrillator, condition affecting the sympathetic nervous system, tremor of the extremities,
• contra-indication to oral morphine ,
• respiratory failure, severe hepatic insufficiency, intracranial hypertension, epilepsy associations
• recent administration of neostigmine or of atropine.

Lung surgical patients