Pre-operative parental anxiety.

This study attempts to identify the incidence and specific sources of anxiety in the parents of children admitted to hospital for elective surgery, to isolate factors associated with increased anxiety and to identify useful ameliorative measures. One hundred parents were interviewed and completed a questionnaire before their child's surgery. Parental anxiety levels were measured using the Leeds scale for self-assessment of anxiety. Anxiety-related illness was identified in 47% of parents, who were significantly more concerned than others about all aspects of their children's hospitalisation. No factors were identified which could predict which parents were at high risk of developing an anxiety state. When questioned about educational and interventional measures which they felt would be reassuring, the same factors were identified by 'anxious' and 'non-anxious' parents. As all parents agree on useful ameliorative factors, a general advice and education programme would be appropriate.

Premedication with oral midazolam in children--an assessment of psychomotor function, anxiolysis, sedation and pharmacokinetics.

We studied 30 children, aged 4 to 12 years, undergoing elective circumcision, premedicated with midazolam 0.5 mg.kg-1 and atropine 0.02 mg.kg-1 by mouth. A modified postbox test and the coding component of the Wechsler intelligence scale (WISC-R) was used to assess the preoperative effect of premedication on psychomotor function. Mood and sedation were also scored and related to serum midazolam concentrations. The children showed a significant decline in psychomotor performance 30 and 60 minutes after premedication when compared with their best unmedicated performance recorded the previous evening. This decline in psychomotor performance was only weakly associated with serum midazolam concentrations (r = 0.1). The postbox toy ratio is a suitable measurement of psychomotor performance in children because of its simplicity and ease of use in the clinical environment, although it may suffer the "test-retest" limitations of similar types of assessment. The sedative and anxiolytic effects of midazolam provide a quiet environment for a smooth induction of anaesthesia.

The effect of premedication on oxygen saturation during the post-premedication period in 20 Chinese children undergoing elective surgery.

Peri-operative continuous pulse oximetric data were studied in healthy Chinese children randomly allocated to receive either pethidine 1 mg kg-1 and atropine 0.02 mg kg-1 intramuscularly 90 min prior to surgery (n = 10), or midazolam 0.5 mg kg-1 and atropine 0.02 mg kg-1 orally, 120 min before surgery (n = 10). Data were collected during the night before surgery, after premedication and for 8 h post-operatively. The pulse oximeter (Nellcor N-200E) output was retrospectively evaluated using Satmaster, a computer programme which permits storage, retrieval, signal evaluation and compilation of oximetric data. There was no significant difference in the frequency, duration, or magnitude ofdesaturation episodes recorded during the post-premedication period compared to the desaturation episodes which occurred in the same child during normal sleep, on the night before surgery. Furthermore, there was no significant difference in the desaturation data between the two premedicant regimens. No child recorded a genuine desaturation less than 80% for longer than 15 s at any time during the study. Neither regimen significantly depressed saturation in otherwise healthy children presenting for minor surgical procedures.

Changes in residual volume relative to vital capacity and total lung capacity after arthrodesis of the spine in patients who have adolescent idiopathic scoliosis.

We evaluated pulmonary functions before correction and again after a mean follow-up of three years in thirty-five patients who had adolescent idiopathic scoliosis. The mean age (and standard deviation) at the time of correction was 13.7 +/- 1.8 years, and at the time of follow-up it was 17.1 +/- 2.5 years. The findings in the patients were compared with those in matched normal control subjects. With the exception of forced vital capacity, all of the determinations of absolute pulmonary volume increased postoperatively, but the increases were not all proportional. When the preoperative and follow-up determinations were expressed as percentages of the predicted pulmonary volumes (on the basis of age) to eliminate any effects of the difference in age, there was no change in total lung capacity, but vital capacity and forced vital capacity were significantly reduced. In addition, there was a significant increase in residual volume. Of the mean increase in total lung capacity after correction of the scoliosis, 82 per cent was due to an increase in residual volume and 18 per cent, to an increase in vital capacity. However, in control subjects age-matched at the time of follow-up, the increase in vital capacity contributed 69 per cent of the mean increase in total lung capacity, a very marked difference from the findings in the patients who had scoliosis. In addition, two pulmonary-volume ratios--residual volume to vital capacity and residual volume to total lung capacity--increased in a highly significant fashion (Mann-Whitney test, p < 0.001) after arthrodesis of the spine.(ABSTRACT TRUNCATED AT 250 WORDS)

An evaluation of prolonged oximetric data acquisition.

Data derived from pulse oximetry has inherent limitations, one of which is artifactual desaturation caused by patient movement. Perioperative patterns of oxygen desaturation were studied for a mean duration of 67 hours in eight young patients following corrective spinal surgery. Pulse oximetry data were relayed to a computer using Satmaster, a program which permits storage, retrieval, signal evaluation and statistical analysis of oximetry data. Desaturation episodes were mild, of short duration and their infrequent occurrence was not increased during intravenous morphine infusion. Retrospective identification of contemporaneous artifactual changes in signal amplitude permitted the removal of artifactual desaturations from our statistical data analysis. This decreased the average time desaturated from 5.4% (220 minutes) to 4.2% (162 minutes) of the monitored period representing a 25% reduction in absolute incidence and a 35% reduction in episodic incidence of desaturation. Acquired data should be validated and inferences drawn from non-validated data must be assessed with caution.

Antagonism of the hypnotic effect of midazolam in children: a randomized, double-blind study of placebo and flumazenil administered after midazolam-induced anaesthesia.

In a randomized, double-blind study, we administered placebo and flumazenil to 40 healthy Chinese boys, aged 3-12 yr, undergoing circumcision. The children received midazolam 0.5 mg kg-1 orally for premedication and 0.5 mg kg-1 i.v. during induction. After operation the patients were given 0.1 ml kg-1 of a blinded solution followed by 0.05 ml kg-1 min-1 until either they awoke or the 10-ml ampoule of solution was empty. Efficacy of antagonism of midazolam was assessed by times to eye opening and self identification, modified Steward coma scale, a post-box toy completion-time ratio and qualitatively by an independent observer. The difference between flumazenil and placebo was both clinically and statistically different in the first 2 h. Children receiving flumazenil awoke approximately four times faster and identified themselves nearly three times sooner; 65% of this group could complete the post-box toy at 10 min, compared with none of the placebo group. There were no cases of resedation, but one child did not awaken for 30 min after i.v. administration of flumazenil 1.0 mg. The mean total dose of flumazenil administered was 0.024 (SD 0.019) mg kg-1. Flumazenil rapidly antagonized midazolam-induced hypnosis in children and was associated with minimal change in cardiorespiratory variables.

A comparison of lignocaine 2% with adrenaline 1:200,000 and lignocaine 2% with adrenaline 1:200,000 plus fentanyl as agents for caudal anaesthesia in children undergoing circumcision.

This randomised double-blind study compares the onset, quality and duration of analgesia in two groups of children (n = 30), aged between two and twelve years undergoing circumcision. Under concurrent general anaesthesia, the children received caudal anaesthesia employing either lignocaine 2% with adrenaline 1:200,000 plus normal saline 0.01 ml/kg, or lignocaine 2% with adrenaline 1:200,000 plus fentanyl 1.0 microgram/kg. The results show no statistical or clinical difference in the onset, duration, quality of pain relief, or side-effects between the two solutions.