Effects of age and emotionality on the effectiveness of midazolam administered preoperatively to children.

BACKGROUND: Multiple studies document the beneficial effect of midazolam on preoperative anxiety in children. Many clinicians report, however, that some children may in fact not benefit from the administration of this drug. METHODS: After screening for relevant exclusion criteria, children undergoing surgery were enrolled in the study (n = 262) and received 0.5 mg/kg oral midazolam at 20-40 min before induction of anesthesia. Personality instruments were administered to all children, and anxiety levels were evaluated before and after administration of midazolam as well as during induction of anesthesia. Blood was drawn during the induction process and later analyzed for midazolam levels. A priori definitions of responders and nonresponders to midazolam were established using a multidisciplinary task force, videotapes of induction, and a validated and reliable anxiety scale, the modified Yale Preoperative Anxiety Scale. RESULTS: While 57% of all children scored at the minimum of the modified Yale Preoperative anxiety scale, 14.1% of children fell in the a priori defined group of midazolam nonresponders. Midazolam blood levels (94 +/- 41 vs. 109 +/- 40 ng/ml) and timing between administration of midazolam and induction (28 +/- 9 vs. 29 +/- 8 min) did not differ between midazolam responders and nonresponders. In contrast, midazolam nonresponders were younger (4.2 +/- 2.3 vs. 5.9 +/- 2.0 yr), more anxious preoperatively (49.7 +/- 22.9 vs. 38.3 +/- 19.1), and higher in emotionality (13.6 +/- 3.6 vs. 11.3 +/- 3.8) as compared with responders (P < 0.05). CONCLUSIONS: Although midazolam is an effective anxiolytic for most children, 14.1% of children still exhibit extreme distress. This subgroup is younger, more emotional, and more anxious at baseline. Future studies are needed to determine the best strategy to treat these children.

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.

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.