Frank Weber

Intraoperative awareness during paediatric anaesthesia

BACKGROUNDnPrevious studies indicate a higher incidence of awareness during anaesthesia in children than in adults, that is, around 1% vs 0.2%. In this prospective cohort study, we determined the incidence of intraoperative awareness in children undergoing elective or emergency surgery at a university childrens hospital.nnnMETHODSnData from 928 consecutive paediatric patients, aged 5-18 yr, were collected prospectively over a 12 month period. Interviews using a structured questionnaire were scheduled at three time points: within 24 h after the operation, and 3-7 and 30 days after operation. Reports of suspected awareness were sent to four independent adjudicators. If they all agreed, the case was classified as a true awareness case.nnnRESULTSnThe interviews generated 26 cases of suspected awareness. Six cases were judged to be true awareness, equalling a 0.6% incidence (95% confidence interval 0.03-1.40%). Auditory and sensory perceptions were the sensations most reported by these six children. Pain, anxiety, and paralysis were less often mentioned. The children in general did not report awareness as stressful.nnnCONCLUSIONSnThe incidence of awareness in this study, in children undergoing general anaesthesia, is comparable with recent reports from other countries, and appears to be higher than that reported in adults.

Lower bispectral index values in children who are intellectually disabled.

BACKGROUND: Very few data are available on the use of bispectral index (BIS) monitoring in children who are intellectually disabled. Epileptiform electroencephalogram activity, underlying cerebral pathology, or anticonvulsant/spasmolytic therapy might influence BIS monitoring. Our aim in this exploratory study was to first compare BIS values at 4 different stages of anesthesia between intellectually disabled children and controls. Our second aim was to investigate the discriminative properties of BIS between consciousness and unconsciousness for intellectually disabled children and for controls. METHODS: Eighteen intellectually disabled children and 35 control children, aged 2–13 yr, were included. BIS values, landmark events, and standard monitoring values of vital functions were recorded throughout the whole procedure. The performance of BIS in distinguishing between a conscious and unconscious state was assessed from receiver operating characteristic curves. RESULTS: Median (interquartile range) BIS values for the intellectually disabled group were significantly lower than those for controls in the awake state (72 [48–77] vs 97 [84–98], P < 0.001), during stable intraoperative anesthesia (34 [21–45] vs 43 [33–52], P = 0.02), and during return of consciousness (59 [36–68] vs 73 [64–78], P = 0.009). The discriminative properties of the BIS monitor for the state of consciousness were comparable between the 2 groups according to the receiver operating characteristic curves. Nevertheless, the optimal cutoff BIS value for discrimination between conscious and unconscious state was 28 points lower for the intellectually disabled group. CONCLUSIONS: We advise anesthesiologists to be alert to possible lower BIS values in intellectually disabled children. There is a risk that they will inadvertently misinterpret the state of consciousness in intellectually disabled children. New multicenter studies must find the optimal manner of evaluating (un)consciousness in intellectually disabled patients with documented and confirmed specific etiologies of their intellectual disability.

Audiovisual aid viewing immediately before pediatric induction moderates the accompanying parents’ anxiety

Background:u2002 Parents accompanying their child during induction of anesthesia experience stress. The impact of audiovisual aid (AVA) on parental state anxiety and assessment of the child’s anxiety at induction have been studied previously but need closer scrutiny.

A Comparison in Adolescents of Composite Auditory Evoked Potential Index and Bispectral Index During Propofol-Remifentanil Anesthesia for Scoliosis Surgery with Intraoperative Wake-Up Test

BACKGROUND: The electroencephalogram-derived Bispectral Index (BIS), and the composite A-line ARX index (cAAI), derived from the electroencephalogram and auditory evoked potentials, have been promoted as anesthesia depth monitors. Using an intraoperative wake-up test, we compared the performance of both indices in distinguishing different hypnotic states, as evaluated by the University of Michigan Sedation Scale, in children and adolescents during propofol-remifentanil anesthesia for scoliosis surgery. Postoperative explicit recall was also evaluated. METHODS: Twenty patients (aged 10–20 yr) were enrolled. Prediction probabilities were calculated for induction, wake-up test, and emergence. BIS and cAAI were compared at the start of the wake-up test, at purposeful movement to command, and after the patient was reanesthetized. During the wake-up test, patients were instructed to remember a color, and were then interviewed for explicit recall. RESULTS: Prediction probabilities of BIS and cAAI for induction were 0.82 and 0.63 (P < 0.001), for the wake-up test, 0.78 and 0.79 (P < 0.001), and 0.74 and 0.78 for emergence (P < 0.001). During the wake-up test, a significant increase in mean BIS and cAAI (P < 0.05) was demonstrated at purposeful movement, followed by a significant decline after reintroduction of anesthesia. CONCLUSIONS: During induction, BIS performed better than cAAI. Although cAAI was statistically a better discriminator for the level of consciousness during the wake-up test and emergence, these differences do not appear to be clinically meaningful. Both indices increased during the wake-up test, indicating a higher level of consciousness. No explicit recall was demonstrated.

Comparison of Bispectral Index and Composite Auditory Evoked Potential Index for Monitoring Depth of Hypnosis in Children

Background:In pediatric patients, the Bispectral Index (BIS), derived from the electroencephalogram, and the composite A-Line autoregressive index (cAAI), derived from auditory evoked potentials and the electroencephalogram, have been used as measurements of depth of hypnosis during anesthesia. The performance and reliability of BIS and cAAI in distinguishing different hypnotic states in children, as evaluated with the University of Michigan Sedation Scale, were compared. Methods:Thirty-nine children (aged 2–16 yr) scheduled to undergo elective inguinal hernia surgery were studied. For all patients, standardized anesthesia was used. Prediction probabilities of BIS and cAAI versus the University of Michigan Sedation Scale and sensitivity/specificity were calculated. Results:Prediction probabilities for BIS and cAAI during induction were 0.84 for both and during emergence were 0.75 and 0.74, respectively. At loss of consciousness, the median BIS remained unaltered (94 to 90; not significant), whereas cAAI values decreased (60 to 43; P < 0.001). During emergence, median BIS and cAAI increased from 51 to 74 (P < 0.003) and from 46 to 58 (P < 0.001), respectively. With respect to indicate consciousness or unconsciousness, 100% sensitivity was reached at cutoff values of 17 for BIS and 12 for cAAI. One hundred percent specificity was associated with a BIS of 71 and a cAAI of 60. To ascertain consciousness, BIS values greater than 78 and cAAI values above 52 were required. Conclusions:BIS and cAAI were comparable indicators of depth of hypnosis in children. Both indices, however, showed considerable overlap for different clinical conditions.

A Visual Analog Scale to assess anxiety in children during anesthesia induction (VAS-I): Results supporting its validity in a sample of day care surgery patients

The modified Yale Preoperative Anxiety Scale is widely used to assess childrens anxiety during induction of anesthesia, but requires training and its administration is time‐consuming. A Visual Analog Scale, in contrast, requires no training, is easy‐to‐use and quickly completed.

Association between children's emotional/behavioral problems before adenotonsillectomy and postoperative pain scores at home

Children undergoing adenotonsillectomy are at risk of severe postoperative pain and sleep problems. Little is known about the specific child risk factors for these problems.

Use, applicability and reliability of depth of hypnosis monitors in children - a survey among members of the European Society for Paediatric Anaesthesiology

BackgroundTo assess the thoughts of practicing anaesthesiologists about the use of depth of hypnosis monitors in children.MethodsMembers of the European Society for Paediatric Anaesthesiology were invited to participate in an online survey about their thoughts regarding the use, applicability and reliability of hypnosis monitoring in children.ResultsThe survey achieved a response rate of 30% (Nu2009=u2009168). A total of 138 completed surveys were included for further analysis. Sixty-eight respondents used hypnosis monitoring in children (Users) and 70 did not (Non-users). Sixty-five percent of the Users reported prevention of intra-operative awareness as their main reason to apply hypnosis monitoring. Among the Non-users, the most frequently given reason (43%) not to use hypnosis monitoring in children was the perceived lack or reliability of the devices in children. Hypnosis monitoring is used with a higher frequency during propofol anaesthesia than during inhalation anaesthesia. Hypnosis monitoring is furthermore used more frequently in children >u20094xa0years than in younger children. An ideal hypnosis monitor should be reliable for all age groups and any (combination of) anaesthetic drug. We found no agreement in the interpretation of monitor index values and subsequent anaesthetic interventions following from it.ConclusionsPrevention of intraoperative awareness appears to be the most important reason to use hypnosis monitoring in children. The perceived lack of reliability of hypnosis monitoring in children is the most important reasons not to use it. No consensus currently exists on how to adjust anaesthesia according to hypnosis monitor index values in children.