IMAGING

Conscious Sedation Reduces Distress in Children Undergoing Voiding Cystourethrography and Does Not Interfere With the Diagnosis of Vesicoureteric Reflux: A Randomized Controlled Study
Herd DW, McAnulty KA, Keene NA, Sommerville DE
Department of Radiology, Waikato Hospital, Hamilton, New Zealand
AJR Am J Roentgenol. 2006; 187: 1621-6

• Objective: Voiding cystourethrography (VCU) is a distressing procedure for children. Conscious sedation using oral midazolam may reduce this distress, but its use may also alter the ability of the VCU to show vesicoureteric reflux (VUR). The objectives of our study were to assess the effectiveness of conscious sedation using oral midazolam when administered routinely in children undergoing VCU and to ensure that conscious sedation using oral midazolam does not alter the ability of VCU to show VUR.
• Subjects and Methods: Our study was a randomized double-blind controlled trial performed at a university teaching hospital; our study group consisted of children over the age of 1 year who been referred for their first VCU examination from July 2001 to July 2003. Participants were randomized to receive a placebo or midazolam syrup (0.5 mg/kg) before the examination. The primary outcome measures were the Groningen Distress Rating Scale (GDRS) and grading of VUR, as defined by the international grading system established by the International Reflux Study Group.
• Results: There were no serious adverse events. One hundred thirty-nine children were randomized in the study, and 117 underwent complete assessment. Eight who underwent VCU after the study day were included in a “complete case” intention-to-treat analysis. In the placebo group, 34 children (61%) experienced serious distress or severe distress (GDRS score, 3 or 4). In the midazolam group, 16 children (26%) experienced the same degree of distress. There was a significant difference between the GDRS scores (nonlinear mixed-model analysis, p < 0.001) of the two study groups. The number needed to treat to reduce serious or severe distress in one child was 2.9 (95% CI, 1.9-5.5). VUR was identified in 16% of all children. There was no difference in VUR grading between the groups (nonlinear mixed-model analysis, p = 0.31).
• Conclusion: Routine use of oral midazolam (0.5 mg/kg) for conscious sedation of children undergoing VCU reduces distress and does not alter the ability of VCU to show VUR well enough to allow diagnosis.
  
  
• Editorial Comment
  In children, the voiding cystourethrogram (VCUG) although a stressful experience for patients and their parents, is an exam relatively easy to perform by an experienced radiologist. Usually no preparation is needed for children; no cleansing enema, fasting or anesthesia is required. In fact, up to now, the vast majority of radiologists prefers to perform this examination when the child is awake. In selected group of children, particularly those who are excessively frightened (previous VCUG), oral midazolam has been used sporadically in order to reduce anxiety and produce antegrade amnesia (1). In 2003, a randomized double blind study (oral midazolam and placebo) performed in 95 children showed that there was no difference in frequency or grade of vesicoureteric reflux or bladder emptying between the two groups of patients(2). We must emphasize that good results has been obtained only with oral midazolan and not with other drugs. Recent study showed that children who underwent VCUG with sedation using propofol were less likely to void to completion thus impairing the ability to accurately detect vesicoureteral reflux (3).
  The authors of this important study clearly shows that sedation with midazolam facilitates the performance of VCUG in children above 1 year of age, with no impairment in the capacity of detect vesicoureteric reflux. We believe that sedation with oral midazolam should be routinely used in children candidate for VCUG examination since it reduce the stress and has no negative effect on the outcome of the examination.

References
1. Elder JS, Longenecker R: Premedication with oral midazolam for VCUG in children. AJR Am J Roentgenol. 1995; 164: 1229-32.
2. Stokland E. Andreasson S, Jacobsson B, Jodal U, Ljung B: Sedation with midazolam for voiding cystourethrography in children: a randomised double-blind study. Pediatr Radiol. 2003; 33: 247-9.
3. Merguerian PA, Corbett ST, Cravero J: Voiding ability using propofol sedation in children undergoing voiding cystourethrograms: a retrospective analysis. J Urol. 2006; 176: 299-302.

Dr. Adilson Prando
Chief, Department of Radiology
Vera Cruz Hospital
Campinas, São Paulo, Brazil