Extubation in patients undergoing extracorporeal life support.

PURPOSE: Extracorporeal life support (ECLS) is a cardiopulmonary support system used for the treatment of severe cardiac and/or respiratory failure. Mortality is high partly because of the severity of the condition that requires support. The use of ECLS is generally associated with heavy sedation. The aim of this study was to demonstrate the feasibility of stopping sedation, allowing extubation of patients supported by ECLS. METHODS: 196 patients supported by ECLS for a period of 4 years were included. Sedation was stopped as soon as possible to allow extubation. The 44 extubated patients were compared with non-extubated patients. Finally, 24% of patients were not extubated without a determined cause and were compared with extubated patients. RESULTS: The extubated patients had a lower incidence of ventilator-associated pneumonia. In a multivariate analysis, the independent risk factors for death were the duration of ECLS, age and lack of extubation. Stopping sedation and extubation are feasible in selected patients under ECLS. CONCLUSIONS: This strategy could be a survival factor.

Pupillometry to detect pain response during general anaesthesia following unilateral popliteal sciatic nerve block: a prospective, observational study.

CONTEXT: Pupillary reflex dilation appears to be a reliable indicator of response to noxious stimulation even under general anaesthesia. The ability of pupillometry to detect the effects of extremity blocks during continuous infusion of opioids remains unknown. OBJECTIVE: To explore the performance of pupillometry to detect differences in pupillary reflex dilation response to a standardised noxious stimulus applied to each leg following unilateral popliteal sciatic nerve block during continuous infusion of remifentanil. DESIGN: Prospective, observational study. SETTING: University hospital anaesthesia department, between June 2010 and December 2010. PATIENTS: Twenty-four adult patients undergoing elective foot or ankle surgery under general anaesthesia who requested a peripheral nerve block. Unilateral popliteal sciatic nerve block with 0.75% ropivacaine and 1% lidocaine was performed awake. General anaesthesia was maintained with steady-state infusions of propofol and remifentanil. MAIN OUTCOME MEASURE: Video-based pupillometer was used to determine pupillary reflex dilation during tetanic stimulation (60 m, 100 Hz) applied to the skin area innervated by the sciatic nerve for 5 s after the onset of general anaesthesia. RESULTS: Sensory nerve block led to a blunted maximal pupillary reflex dilation response to noxious stimulation compared with the non-blocked leg: median (interquartile range) change from baseline 2% (1 to 4%) versus 17% (13 to 24%), respectively (P < 0.01). The differences in the response persisted throughout the 5-s stimulus and the recovery phase. CONCLUSION: These results are a proof of concept. The effects of peripheral nerve block can be detected via the measurement of pupillary reflex dilation response to noxious stimulation of the skin in patients receiving remifentanil.