B. Julliac

Risk factors for the occurrence of electroencephalogram abnormalities during induction of anesthesia with sevoflurane in nonepileptic patients.

Background:The aim of this prospective study was to determine the risk factors of epileptiform discharge during induction with sevoflurane in healthy adult patients. Methods:Forty adult patients with American Society of Anesthesiologists physical status I were randomly allocated to one of four groups. Group A: Patients breathed 8% sevoflurane in oxygen (8 l/min) via a prefilled circuit. End-tidal sevoflurane was maintained at 4%. Tracheal intubation was performed at the third minute after cisatracurium injection. Group B: The anesthesia protocol was similar, but a vital capacity technique was performed. Group C: Patients were anesthetized as in group A but were hyperventilated. Group D: Patients were anesthetized as in group A, but end-tidal sevoflurane was maintained at 2%. An electroencephalogram was recorded before and during induction up to 11 min after the start of induction. Statistical analysis was performed with Statview 5.0® (SAS Institute Inc., Cary, NC) for multivariate analysis. Results:Twelve patients experienced epileptiform discharges. Risk factors were female sex (odds ratio, 12.60; 95% confidence interval, 1.46–135), delay to the occurrence of β waves (odds ratio, 0.92; 95% confidence interval, 0.86–0.99), and end-tidal sevoflurane (odds ratio, 8.78; 95% confidence interval, 1.12–69). Epileptiform discharges were not associated with significant hemodynamic or Bispectral Index variations. Conclusion:Induction with sevoflurane may result in epileptiform electroencephalographic activity. Only electroencephalographic monitoring allows the diagnosis. Risk factors are mainly female sex, short delay to onset of anesthesia, and high alveolar sevoflurane concentration. Induction with high sevoflurane concentration is controversial mainly in women.

Elevated levels of shed membrane microparticles with procoagulant potential in the peripheral circulating blood of patients with subarachnoid haemorrhage: A-792

Elevated levels of shed membrane microparticles with procoagulant potential in the peripheral circulating blood of patients with subarachnoid haemorrhage M. Biais1, N. Morel2, O. Morel3, L. Petit1, B. Julliac2, A. Lelias1,2, F. Sztark1, Ph. Dabadie2 1DAR I, Hôpital Pellegrin, Bordeaux, France; 2Département des Urgences, Hôpital Pellegrin, Bordeaux, France; 3Fédération de Cardiologie des Hôpitaux Universitaires de Stras Background and Goal of Study: Microparticles (MP) are fragments released from the plasma membrane of most stimulated or apoptotic cells. MP have procoagulant and pro-inflammatory properties. We hypothesized that elevated levels of procoagulant MP could circulate in the peripheral blood of patients who recently underwent subarachnoid haemorrhage (SAH). Materials and Methods: Consecutive patients admitted with SAH were prospectively enrolled. Demographic (age, sex) and neurological (GSW, Hunt-Hess, WFNS and Fisher scores) factors were recorded at admission. The Glasgow Outcome Scale (GOS) at 3 months was evaluated. We isolated the circulating MP by capture with annexine V and determined their procoagulant potential with a prothrombinase assay, at the day of the enrolment (D0) and five days later (D5). The cellular origin of MP was determined by antigenic capture with specific antibodies. As control, circulating MP were measured in 67 healthy patients. Results were expressed as median [Min;Max]. Statistical analysis was performed using Student’s t test and Mann and Whitney test as appropriate. P 0.05 was considered significant. Results and Discussions: We included 16 patients with recent SAH. The mean age was 55 years. The median of the WFNS score was 1 and the median of GCS was 15. The complications were 2 rebleeding, 3 symptomatic vasospasms and 8 acute hydrocephalus (AH). MP levels were significantly higher in SAH group (8.4[2.1–24.7] nMPhtSer Eq) compared with control group (1.57[0.14–9.1] nMPhtSer Eq), P 0.001. Released MP in patients with recent SAH had platelet origin. MP levels decreased significantly between D0 and D5 in patients without rebleeding (P 0.01), and increased in patients with rebleeding. MP were significantly increased in patients with lower Fisher score (P 0.01), lower AH incidence (P 0.05) and better clinical outcome evaluated by GOS (P 0.05). Conclusion: High levels of procoagulant platelet MP are present in circulating blood of patients with recent SAH and are associated with a lower bleeding, a decrease of AH incidence and with a good clinical outcome. Reference: 1 Zwall RF, Schroit AJ. Blood 1997; 89(4):1121–32.