Family-centered preparation for surgery improves perioperative outcomes in children: a randomized controlled trial.

BACKGROUND: Children and parents experience significant anxiety and distress during the preoperative period. Currently available interventions are having limited efficacy. Based on an integration of the literature in both the anesthesia and psychological milieus, the authors developed a behaviorally oriented perioperative preparation program for children undergoing surgery that targets the family as a whole. METHODS: Children and their parents (n = 408) were randomly assigned to one of four groups: (1) control: received standard of care; (2) parental presence: received standard parental presence during induction of anesthesia; (3) ADVANCE: received family-centered behavioral preparation; and (4) oral midazolam. The authors assessed the effect of group assignment on preoperative anxiety levels and postoperative outcomes such as analgesic consumption and emergence delirium. RESULTS: Parents and children in the ADVANCE group exhibited significantly lower anxiety in the holding area as compared with all three other groups (34.4+/-16 vs. 39.7+/-15; P=0.007) and were less anxious during induction of anesthesia as compared with the control and parental presence groups (44.9+/-22 vs. 51.6+/-25 and 53.6+/-25, respectively; P=0.006). Anxiety and compliance during induction of anesthesia was similar for children in both the ADVANCE and midazolam groups (44.9+/-22 vs. 42.9+/-24; P=0.904). Children in the ADVANCE group exhibited a lower incidence of emergence delirium after surgery (P=0.038), required significantly less analgesia in the recovery room (P=0.016), and were discharged from the recovery room earlier (P=0.04) as compared with children in the three other groups. CONCLUSION: The family-centered preoperative ADVANCE preparation program is effective in the reduction of preoperative anxiety and improvement in postoperative outcomes.

What pediatricians should know about child-related malpractice payments in the United States.

OBJECTIVE: The purpose of this study was to examine child-related National Practitioner Data Bank data. METHODS: Data were obtained from the National Practitioner Data Bank. RESULTS: the period from February 1, 2004, through December 31, 2005, a total of 30195 malpractice payments were made on behalf of practitioners in the United States; 14% of those payments (4107 of 30,195 payments) were child related. During the period analyzed, $1.73 billion were paid for malpractice cases involving children. More than 95% of all payments were the result of settlements and only approximately 5% the result of judgments. The average child-related malpractice payment was significantly greater than an adult-related malpractice payment ($422,000 vs $247,000); however, child-related malpractice payments were only one half as likely to occur, compared with adult-related malpractice payments. Significant geographic variability was found in the numbers and sizes of child-related malpractice payments. Failure to diagnose was the leading reason for child-related payments (18%), followed by improper performance (9%), delay in diagnosis (9%), and improper management (6%). Finally, we found that approximately 40% of all malpractice awards were the result of surgical or obstetrical issues. CONCLUSIONS: Practicing pediatricians should be aware of the existence of a mandatory electronic depository that documents all malpractice settlements and judgments involving practitioners.

Preoperative anxiety, postoperative pain, and behavioral recovery in young children undergoing surgery.

OBJECTIVE: Findings from published studies suggest that the postoperative recovery process is more painful, slower, and more complicated in adult patients who had high levels of preoperative anxiety. To date, no similar investigation has ever been conducted in young children. METHODS: We recruited 241 children aged 5 to 12 years scheduled to undergo elective outpatient tonsillectomy and adenoidectomy. Before surgery, we assessed child and parental situational anxiety and temperament. After surgery, all subjects were admitted to a research unit in which postoperative pain and analgesic consumption were assessed every 3 hours. After 24 hours in the hospital, children were discharged and followed up at home for the next 14 days. Pain management at home was standardized. RESULTS: Parental assessment of pain in their child showed that anxious children experienced significantly more pain both during the hospital stay and over the first 3 days at home. During home recovery, anxious children also consumed, on average, significantly more codeine and acetaminophen compared with the children who were not anxious. Anxious children also had a higher incidence of emergence delirium compared with the children who were not anxious (9.7% vs 1.5%) and had a higher incidence of postoperative anxiety and sleep problems. CONCLUSIONS: Preoperative anxiety in young children undergoing surgery is associated with a more painful postoperative recovery and a higher incidence of sleep and other problems.

Predicting which children benefit most from parental presence during induction of anesthesia.

BACKGROUND: The purpose of this large-scale prospective cohort study (n = 426) was to identify child and parent characteristics that are associated with low anxiety and good compliance during induction of anesthesia when parents are present. METHODS: Outcome variables included child's anxiety and child's compliance during induction of anesthesia. Predictor variables included demographics, temperament, trait (baseline) anxiety, coping style, and locus of control. RESULTS: Results of a linear regression model (overall proportion of variance accounted for equals 39.5%) showed that significant predictors of anxiety during induction of anesthesia while parents are present included: the child's age (DeltaR(2) = 0.315, P = 0.0001), behavior during previous medical visits (DeltaR(2) = 0.025, P = 0.001), child's activity level (DeltaR(2) = 0.016, P = 0.007), parent's state (contextual) anxiety (DeltaR(2) = 0.022, P = 0.001) and parent's locus of control (DeltaR(2) = 0.009, P = 0.036). A linear regression model that was constructed with compliance of the child as the outcome revealed similar findings. CONCLUSIONS: Children who benefit from parental presence are older, had lower levels of activity in their temperament, and had parents who were calmer and who valued preparation and coping skills for medical situations. The practical implications of these findings are discussed.

Psychological predictors of postoperative sleep in children undergoing outpatient surgery.

BACKGROUND: The purpose of this study was to examine psychological predictors of postoperative sleep in children undergoing outpatient surgery. METHODS: We used hierarchical multivariate regression to examine the impact of demographic and personality variables such as parental worry/anxiety [NEO-personality inventory, revised (NEO-PI-R) Neuroticism], parental coping style (Miller Behavioral Style Scale), children's aggressive behavior [child behavior checklist (CBCL) externalizing], and children's temperament (emotionality, activity, sociability, and impulsivity) on postoperative sleep in 52 consecutive, healthy, children undergoing outpatient surgery. Sleep was assessed using actigraphy, a valid, reliable and objective measure of sleep quality. All perioperative protocols were strictly controlled and standardized. RESULTS: We found that 22% of the children experienced difficulty with postoperative sleep as defined by actigraphy. A hierarchical multiple regression model that was constructed to identify predictors of postoperative sleep efficiency in children accounted for 82% of the variance (R = 0.906, F = 19.42, P = 0.0001). Significant predictors in this model included preoperative sleep patterns (60%), postoperative pain (8.2%), parental anxiety/worry (NEO-PI-R Neuroticism scale; 9%), and children's aggressive behavior (CBCL externalizing; 5%). CONCLUSIONS: We conclude that psychological factors such as parental anxiety/worry and children's aggressive behavior are predictive of children's postoperative sleep above and beyond the influence of preoperative sleep patterns and postoperative pain.

Predicting which child-parent pair will benefit from parental presence during induction of anesthesia: a decision-making approach.

Using a multiply matched, concurrent cohort analysis, with 568 subjects matched from data obtained by our laboratory over the past 7 yr, we examined whether parental presence during induction of anesthesia (PPIA) reduces children's anxiety depending on the interaction between child and parent's baseline anxiety. Children's and parents' baseline anxiety was assessed preoperatively; children's anxiety was again assessed during induction of anesthesia. We found that anxious children who received PPIA from a calm parent were significantly less anxious during induction of anesthesia as compared with anxious children who did not receive PPIA (P = 0.03). In contrast, calm children who received PPIA from an overly anxious parent were significantly more anxious as compared with calm children who were not accompanied by a parent (P = 0.002). We found no effect of PPIA on children's anxiety during induction of anesthesia when calm parents accompanied calm children into the operating room (P = 0.15) or when overly anxious parents accompanied anxious children (P = 0.49). We conclude that the presence of a calm parent does benefit an anxious child during induction of anesthesia and the presence of an overly anxious parent has no benefit.

Behavioral interactions in the perioperative environment: a new conceptual framework and the development of the perioperative child-adult medical procedure interaction scale.

BACKGROUND: The authors suggest that research in the area of parental presence during induction of anesthesia should shift to emphasize what parents actually do during induction, rather than focusing simply on their presence. As a first step, the authors aimed to develop a behavioral coding system that would measure child and adult interactions in the perioperative environment. METHODS: The authors enrolled 45 parents and children (aged 2-12 yr) undergoing elective surgery and general anesthesia. A multidisciplinary team examined videotapes and transcriptions of interactions between children, parents, and medical personnel in the holding room and operating room. The team used an existing scale, the Child-Adult Medical Procedure Interaction Scale, as the prototype for the development of a new perioperative behavioral coding system. The research team conducted extensive revisions to the original scale and added multiple codes to the original scale, including nonverbal codes. Interrater reliability was assessed using weighted kappa statistics. Construct validity was also examined. RESULTS: The final Perioperative Child-Adult Medical Procedure Interaction Scale contains 40 codes in four domains. Analyses showed excellent reliability overall for verbal and nonverbal codes. Kappa values averaged 0.87 for verbal codes characterizing adult vocalizations, 0.92 for verbal codes characterizing child vocalizations, and 0.88 for nonverbal codes. Construct validity was demonstrated by finding the hypothesized associations between certain scale codes and children's anxiety (P = 0.0001). CONCLUSION: Showing excellent reliability, the Perioperative Child-Adult Medical Procedure Interaction Scale is an appropriate tool for assessing child-adult behavioral interaction during the perioperative period. When sequential analyses are conducted and target behaviors are identified, empirically based parent preparation programs can be developed.

Preoperative psychological preparation of the child for surgery: an update.

Preoperative anxiety is associated with a number of poor postoperative outcomes and with significant parental and child distress before surgery. Preparing children for surgery can prevent many behavioral and physiologic manifestations of anxiety. Psychologic and behavioral interventions and pharmacologic interventions are available to treat preoperative anxiety in children. This article discusses the psychologic preparation of children for surgery.

Motivation and maternal presence during induction of anesthesia.

BACKGROUND: The authors developed a measure to determine whether maternal motivation to be present during induction (Motivation for Parental Presence during Induction of Anesthesia [MPPIA]) is related to children's anxiety during the induction process. METHODS: Mothers and children (aged 2-12 yr) undergoing outpatient, elective surgery and general anesthesia were enrolled in this study (n = 289 dyads). Items to assess motivation for parental presence during induction were selected by experts in anesthesiology, psychology, and child development; mothers completed the resulting 14-item measure as well as assessments of anxiety and coping style. Children's anxiety and compliance was assessed during induction of anesthesia. Factor analysis was performed, and maternal motivation was then examined against children's anxiety during induction of anesthesia. RESULTS: Factor analysis resulted in four scales with a total variance of 72.3%: MPPIA-Desire, MPPIA-Hesitancy, MPPIA-Anxiety, and MPPIA-Preparation. Analysis supported the reliability (0.89-0.94) and validity of the MPPIA. The authors found that mothers with high MPPIA-Desire and low MPPIA-Hesitancy had children with significantly higher anxiety (P < 0.0001) during induction of anesthesia, as compared with mothers with low MPPIA-Desire and MPPIA-Hesitancy. The authors also found that highly motivated mothers reported significantly higher levels of anxiety (P = 0.007). CONCLUSION: Clinicians should be aware that many mothers who have a high desire to be present in the operating room are very anxious and that their children are likely to exhibit high anxiety levels during induction of anesthesia.

Acupressure and preoperative parental anxiety: a pilot study.

In this randomized sham-controlled study we examined the anxiolytic and sedative effects of acupressure on parents in the preoperative holding area before their children's surgery. Sixty-one parents received acupressure either at the Yintang point (midpoint between the two eyebrows) or at a sham point. Anxiety (as measured by the Stait-Trait Anxiety Inventory), arterial blood pressure, and heart rate were assessed before and after the intervention and a Bispectral Index monitor was used to continuously monitor hypnotic sedation levels. Repeated-measures analysis of variance showed that parents in the acupressure group reported significantly less anxiety at 20 min post-intervention as compared with parents in the sham group (37 +/- 10 versus 45 +/- 13, P = 0.03). Bispectral Index values, heart rate, and arterial blood pressure, however, did not differ between the two study groups (P = not significant). We conclude that acupressure at the Yintang point may be used as a treatment for parental preoperative anxiety. Future studies are needed to quantify the magnitude and duration of the anxiolytic effect.

Complementary and alternative medicine for low-back pain in pregnancy: a cross-sectional survey.

OBJECTIVE: To identify common treatments used for low-back pain (LBP) during pregnancy. DESIGN: A two-part anonymous survey. SETTING/LOCATION: New Haven, Connecticut. SUBJECTS: Pregnant women and providers of prenatal health care (nurse educators, nurse midwives, and obstetricians). RESULTS: We found that the majority of pregnant women who participated in our survey (61.7%) reported that they would accept complementary and alternative medicine (CAM) therapy as treatment for LBP during pregnancy. Similarly, 61% of providers of prenatal health care in our sample reported that they would consider using CAM as treatment for LBP during pregnancy. Massage (61.4%), acupuncture (44.6%), relaxation (42.6%), yoga (40.6%), and chiropractic (36.6%) were the most common CAM therapies recommended for LBP in pregnancy by the providers of prenatal health care in our sample. CONCLUSIONS: This two-part survey study found that both providers of prenatal health care and pregnant women in New Haven county are likely to use CAM treatments for pregnancy-induced LBP. Further investigation should focus on whether it is a nationwide phenomenon, as well as if various CAM therapies are an efficacious treatment for LBP during pregnancy.

Sevoflurane versus halothane: postoperative maladaptive behavioral changes: a randomized, controlled trial.

BACKGROUND: The authors conducted a double-blind, randomized, controlled trial to determine whether the use of sevoflurane in children undergoing anesthesia and surgery results in a higher incidence of postoperative maladaptive behavioral changes as compared with halothane. METHODS: Children and their parents (n = 102) were randomly assigned to either a halothane group (n = 50) or a sevoflurane group (n = 52). The intraoperative anesthetic protocol was strictly controlled, and the postoperative analgesic consumption and pain levels were recorded. The effect of the group assignment on emergence status and maladaptive postoperative behavioral changes was assessed both by validated psychological measures and physiologic instruments (actigraphy) on postoperative days 1-7. Anxiety of the parent and child was also assessed, as was the child's postoperative recovery (Recovery Inventory). RESULTS: There were no group differences in preoperative state anxiety, postoperative analgesic requirements, postoperative pain, or the incidence of emergence delirium (P = not significant). Two-way repeated-measures analysis of variance showed no group differences in the incidence of postoperative maladaptive behaviors (F4,72 = 0.60, P = 0.701) or actigraphic variables such as percent sleep, number of night awakenings, and night awakenings that lasted for more than 5 min (P = not significant). CONCLUSION: The authors found no increased incidence of emergence delirium, maladaptive postoperative behavior changes, or sleep disturbances in children undergoing anesthesia with sevoflurane as compared with halothane.

Preoperative anxiety and emergence delirium and postoperative maladaptive behaviors.

Based on previous studies, we hypothesized that the clinical phenomena of preoperative anxiety, emergence delirium, and postoperative maladaptive behavioral changes were closely related. We examined this issue using data obtained by our laboratory over the past 6 years. Only children who underwent surgery and general anesthesia using sevoflurane/O(2)/N(2)O and who did not receive midazolam were recruited. Children's anxiety was assessed preoperatively with the modified Yale Preoperative Anxiety Scale (mYPAS), emergence delirium was assessed in the postanesthesia care unit, and behavioral changes were assessed with the Post Hospital Behavior Questionnaire (PHBQ) on postoperative days 1, 2, 3, 7, and 14. Regression analysis showed that the odds of having marked symptoms of emergence delirium increased by 10% for each increment of 10 points in the child's state anxiety score (mYPAS). The odds ratio of having new-onset postoperative maladaptive behavior changes was 1.43 for children with marked emergence status as compared with children with no symptoms of emergence delirium. A 10-point increase in state anxiety scores led to a 12.5% increase in the odds that the child would have a new-onset maladaptive behavioral change after the surgery. This finding is highly significant to practicing clinicians, who can now predict the development of adverse postoperative phenomena, such as emergence delirium and postoperative behavioral changes, based on levels of preoperative anxiety.

Low back pain during pregnancy: prevalence, risk factors, and outcomes.

OBJECTIVE: To estimate the severity of the low back pain (LBP) during pregnancy, including prevalence, risk factors, impact on daily living, and health provider management. METHODS: An anonymous survey consisting of 36 questions was distributed to pregnant women participating in various prenatal care clinics and educational classes in New Haven County, Connecticut. A total of 950 surveys was returned from May 2002 through October 2003. At each site, a researcher was available each week to answer questions and gather surveys. RESULTS: Six hundred forty-five (68.5%; 95% confidence interval [CI] 65-72%) respondents reported experiencing LBP during their current pregnancy. The prevalence was not affected by gestational age (P =.56). Low back pain during the current pregnancy was predicted by age (younger women were more likely to develop it; P =.004), history of LBP without pregnancy (P =.002), during menstruation (P =.01), and during a previous pregnancy (P =.002). The majority of respondents reported that LBP during pregnancy caused sleep disturbances (58%; 95% CI 54-62%) and impaired daily living (57%; 95% CI 53-62%). Average pain was moderate in severity. Nearly 30% of respondents stopped performing at least one daily activity because of pain and reported that pain also impaired the performance of other routine tasks. Only 32% (95% CI 28-36%) of the respondents with LBP during pregnancy informed their prenatal care providers of this problem, and only 25% (95% CI 21-28%) of prenatal care providers recommended a treatment. CONCLUSION: Low back pain during pregnancy is a common problem that causes hardship in this population. Further studies are indicated in the areas of prevention and treatment.

Parental auricular acupuncture as an adjunct for parental presence during induction of anesthesia.

BACKGROUND: The purpose of this study was to determine whether parental auricular acupuncture reduces parental preoperative anxiety and thus allows children to benefit from parental presence during induction of anesthesia. METHODS: Mothers of children who were scheduled to undergo surgery were randomly assigned to an acupuncture intervention group (auricular press needles at relaxation, tranquilizer point, and master cerebral point) or a sham acupuncture control group (auricular press needles at the shoulder, wrist, and extraneous auricular point). The intervention was performed at least 30 min before the child's induction of anesthesia. All mothers were present during induction of anesthesia. The behavioral and physiologic anxiety of mothers and children were rated during the perioperative process. RESULTS: : Multivariable analysis examining maternal anxiety as a function of group found a group-by-time interaction (F1,65 = 4.1, P = 0.04). That is, after induction, maternal anxiety in the acupuncture group was significantly lower (42.9 +/- 10 vs. 49.5 +/- 11; P = 0.014). A multivariate model (F1,65 = 4.8, P =0.031) also showed that children whose mothers received the acupuncture intervention were significantly less anxious on entrance to the operating room (34.9 +/- 20 vs. 47.4 +/- 26; P = 0.03) and during introduction of the anesthesia mask (38.6 +/- 25 vs. 55.6 +/- 31; P = 0.016). There were no significant differences in maternal blood pressure and heart rate between the two groups. CONCLUSIONS: : Auricular acupuncture significantly decreased maternal anxiety during the preoperative period. Children of mothers who underwent acupuncture intervention benefitted from the reduction of maternal anxiety during the induction of anesthesia.

Trends in the practice of parental presence during induction of anesthesia and the use of preoperative sedative premedication in the United States, 1995-2002: results of a follow-up national survey.

UNLABELLED: Both parental presence during induction of anesthesia and sedative premedication are currently used to treat preoperative anxiety in children. A survey study conducted in 1995 demonstrated that most children are taken into the operating room without the benefit of either of these two interventions. In 2002 we conducted a follow-up survey study. Five thousand questionnaires were mailed to randomly selected physician members of the American Society of Anesthesiologists. Mailings were followed by a nonresponse bias assessment. Twenty-seven percent (n = 1362) returned the questionnaire after 3 mailings. We found that a significantly larger proportion of young children undergoing surgery in the United States were reported to receive sedative premedication in 2002 as compared with 1995 (50% vs 30%, P = 0.001). We also found that in 2002 there was significantly less geographical variability in the use of sedative premedication as compared with the 1995 survey (F = 8.31, P = 0.006). Similarly, we found that in 2002 parents of children undergoing surgery in the United States were allowed to be present more often during induction of anesthesia as compared with 1995 (chi(2) = 26.3, P = 0.0001). Finally, similar to our findings in the 1995 survey, midazolam was uniformly selected most often to premedicate patients before surgery. IMPLICATIONS: Over the past 7 yr there have been significant increases in the number of anesthesiologists who use preoperative sedative premedication and parental presence for children undergoing surgery.

Interactive music therapy as a treatment for preoperative anxiety in children: a randomized controlled trial.

UNLABELLED: In this study, we examined whether interactive music therapy is an effective treatment for preinduction anxiety. Children undergoing outpatient surgery were randomized to 3 groups: interactive music therapy (n = 51), oral midazolam (n = 34), or control (n = 38). The primary outcome of the study was children's perioperative anxiety. We found that children who received midazolam were significantly less anxious during the induction of anesthesia than children in the music therapy and control groups (P = 0.015 and P = 0.005, respectively). We found no difference in anxiety during the induction of anesthesia between children in the music therapy group and children in the control group. An analysis controlling for therapist revealed a significant therapist effect; i.e., children treated by one of the therapists were significantly less anxious than children in the other therapist group and the control group on separation to the operating room (OR) (P < 0.05) and on entrance to the OR (P < 0.05), but not on the introduction of the anesthesia mask (P = not significant). Children in the midazolam group were the least anxious even after controlling for therapist effect (P < 0.05). We conclude that music therapy may be helpful on separation and entrance to the OR, depending on the therapist. However, music therapy does not appear to relieve anxiety during the induction of anesthesia. IMPLICATIONS: Depending on the music therapist, interactive music therapy may relieve anxiety on separation and entrance to the operating room but appears less effective during the induction of anesthesia.

Sleeping characteristics of adults undergoing outpatient elective surgery: a cohort study.

STUDY OBJECTIVE: To describe sleeping patterns of adults before and after outpatient surgery. DESIGN: Observational cohort study. SETTING: Outpatient surgical facility. PATIENTS: 127 consenting adults, including 92 surgery patients and 35 community controls. INTERVENTIONS: Participants' sleep was measured for two days before and 2 days after outpatient surgery. MEASUREMENTS: Sleep was measured using actigraphy; additional measurements were made of anxiety (STAI), pain and energy (VAS), recovery (PHRI), and sleep history. MAIN RESULTS: Approximately 23% of patients experienced clinically significant sleep impairment after surgery, a more difficult recovery, increased pain, and lower energy. In contrast, only 2.9% of the community control group experienced clinically significant sleep impairment during the same time period. Also, patients in the surgery group experienced significantly more True Wake Time postoperatively than did control patients (p = 0.029). The surgery group also experienced more Night Awakenings >5 minutes than the control group (p = 0.006), but not more overall Night Awakenings (p = 0.106). Finally, of the patients in the surgery group, those who had higher state anxiety in the holding area also had more difficulty sleeping over the 4-day monitoring period (True Sleep Time was lower, 352 +/- 187 vs. 229 +/- 225, p = 0.009). CONCLUSIONS: A moderate proportion of adults experience postoperative sleeping problems.

The use of complementary and alternative medicines by surgical patients: a follow-up survey study.

UNLABELLED: In a previous study, we indicated that 42% of surgical outpatients are interested in using acupuncture as a treatment modality for preoperative anxiety. We designed this follow-up survey to assess differences in attitude toward complementary-alternative medical therapies (CAM) between patients undergoing outpatient surgeries and those undergoing inpatient surgeries. The results indicate that most surgical patients (57.4%) use some form of CAM, including self-prayer (praying for their own health; 29%), chiropractic treatment (23%), massage therapy (15%), relaxation (14%), herbs (13%), megavitamins (9%), and acupuncture (7%). Inpatient surgical respondents reported using self-prayer more than outpatient surgical respondents, but no other differences in CAM use were found between inpatient and outpatient respondents. More inpatient respondents reported disclosing their usage of CAM to perioperative physicians than did outpatient respondents. Most surgical patients were willing to accept CAM as part of their perioperative management but were not willing to pay out-of-pocket for CAM treatment. The leading CAM therapies that fewer of the respondents were willing to pay for out-of-pocket included relaxation, massage, chiropractic medicine, herbs, and acupuncture. IMPLICATIONS: Most surgical patients use some form of complementary-alternative medical therapies (CAM) and are willing to accept CAM therapy as part of their perioperative management.

Hemispheric synchronized sounds and intraoperative anesthetic requirements.

Hemispheric synchronization is currently promoted as a treatment for preoperative anxiety and for reduction of intraoperative anesthetic and analgesic consumption. We designed this study to examine the effect of Hemisync sounds on anesthetic hypnotic depth. After obtaining informed consent, we randomized subjects undergoing general anesthesia and outpatient surgery into two groups: the treatment group received Hemisync sounds (n = 31), and the control group received a blank cassette tape (n = 29). Both groups received the intervention in the preoperative area and during the surgical procedure. Subjects underwent a propofol-based anesthetic regimen, and propofol doses required for the induction and maintenance of anesthesia were recorded. A bispectral index monitor was used to ensure that the hypnotic component of the anesthetic state was the same in all patients. We found no differences in the amount of propofol used during the induction of anesthesia (2.49 +/- 0.59 mg/kg versus 2.60 +/- 0.59 mg/kg; P = 0.48) or the maintenance of anesthesia (0.141 +/- 0.02 mg x kg(-1) x min(-1) versus 0.146 +/- 0.04 mg x kg(-1) x min(-1); P = 0.62) between the Hemisync and control groups. We also found no differences between the Hemisync group and the control group for participants with high state anxiety (P = not significant). We conclude that Hemisync sounds do not reduce the hypnotic component of the anesthetic state of patients undergoing general anesthesia and surgery.