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BACKGROUND The Pupillary Pain Index is a recent pupillometric index designed to assess the level of analgesia under general anesthesia in children and adults. If analgesia is inadequate, acute nociceptive stimuli such as skin incision may induce significant hemodynamic disturbances. AIMS Our aim was to investigate the potential relationship between pre-incision Pupillary Pain Index and heart rate increase following skin incision in children. METHODS This was a prospective, non-randomized, registered pilot study. We included children undergoing surgery under general anesthesia. Pupillary Pain Index was assessed 2 min before skin incision. Then, heart rate maximal variation (ΔHR ) and pupillary diameter maximal variation (ΔPD ) in the minute following incision were recorded. Spearman coefficient was calculated to characterize the relationship between Pupillary Pain Index and ΔHR or ΔPD . Using receiver operating characteristic curve analysis, we also studied the predictive value of pre-incision Pupillary Pain Index for heart rate and pupillary diameter reactivity. RESULTS 53 patients were included (10 ± 4 years, 40 ± 19 kg). There was a modest correlation between pre-incision Pupillary Pain Index and ΔHR (Spearman rs = 0.35 [0.05-0.57], p = .011), and between pre-incision Pupillary Pain Index and ΔPD (Spearman rs = 0.54 [0.33-0.71], p

International audience; BACKGROUND : In this prospective study, we describe the electroencephalographic (EEG) profiles in children anesthetized with sevoflurane or propofol.METHODS : Seventy-three subjects (11 years, range 5-18) were included and randomly assigned to two groups according to the anesthetic agent. Anesthesia was performed by target-controlled infusion of propofol (group P) or by sevoflurane inhalation (group S). Steady-state periods were performed at a fixed randomized concentration between 2, 3, 4, 5, and 6 μg.ml-1 of propofol in group P and between 1, 2, 3, 4, and 5% of sevoflurane in group S. Remifentanil was continuously administered throughout the study. Clinical data, Bispectral Index (BIS), and raw EEG were continuously recorded. The relationship between BIS and anesthetic concentrations was studied using nonlinear regression. For all steady-state periods, EEG traces were reviewed to assess the presence of epileptoid signs, and spectral analysis of raw EEG was performed.RESULTS : Under propofol, BIS decreased monotonically and EEG slowed down as concentrations increased from 2 to 6 μg.ml-1 . Under sevoflurane, BIS decreased from 0% to 4% and paradoxically rose from 4% to 5% of expired concentration: this increase in BIS was associated with the occurrence of fast oscillations and epileptoid signs on the EEG trace. Propofol was associated with more delta waves and burst suppression periods compared to sevoflurane.CONCLUSION : Under deep anesthesia, the BIS and electroencephalographic profiles differ between propofol and sevoflurane. For high concentrations of sevoflurane, an elevated BIS value may be interpreted as a sign of epileptoid patterns or EEG fast oscillations rather than an insufficient depth of hypnosis.

International audience

Summary Background Analgesia and nociception can not be specifically monitored during general anesthesia. Movement of the patient or hemodynamic variations are usually considered as symptoms of insufficient analgesia. The measure of skin conductance (SC) allows an assessment of peripheral sympathetic activity. The analgesia-nociception index (ANI) provides an evaluation of the parasympathetic activity based on heart rate variability. These two non-invasive monitors might allow a better assessment of perioperative nociception. Objectives Describe the profiles of SC and ANI after a standardized nociceptive stimulation, in anesthetized children, at different infusion rates of remifentanil. Materials/Methods For this pilot study, 12 children (8.4 ± 5 years) scheduled for middle-ear surgery were anesthetized with desflurane to maintain a bispectral index at 50. Remifentanil was used for analgesia, at an initial infusion rate of 0.2 μg·kg−1·min−1. Remifentanil infusion rate was then decreased: Five steady-state periods of 10 min were obtained at 0.2, 0.16, 0.12, 0.08, and 0.04 μg·kg−1·min−1. At the end of each period, a standardized tetanic stimulation was applied to the patient. Variations in heart rate, blood pressure, SC, and ANI were recorded before and after each stimulation. Results After the stimulation, ANI was significantly decreased compared with prestimulation values for all remifentanil infusion rates. This decrease was greater at 0.04 μg·kg−1·min−1 than at the other infusion rates. SC, heart rate, and blood pressure were not modified by the stimulations, whatever the dose of remifentanil. Conclusion ANI might provide a more sensitive assessment of nociception in anesthetized children than hemodynamic parameters or skin conductance.