Carbon dioxide versus room air for colonoscopy in deeply sedated pediatric patients: a randomized controlled trial

Abstract

Background and study aims Use of carbon dioxide (CO ₂ ) instead of room air (RA) during colonoscopy in adults revealed significantly less flatulence and abdominal pain in several studies. The objectives of this study were to investigate the effects of CO ₂ usage on post-interventional pain, abdominal discomfort, abdominal girth, pCO ₂ levels, and narcotic requirement in deeply sedated pediatric patients. Patients and methods A total of 97 children and adolescents aged 4 years to 17 years undergoing colonoscopy were randomized to RA or CO ₂ in a prospective, randomized, controlled trial. Age-appropriate pain scales assessed abdominal pain as primary outcome. In addition, abdominal girth, abdominal bloating, transcutaneous pCO ₂ , narcotic requirement to achieve deeply sedation, and post-procedural analgesic demand was analyzed in 73 patients. Results Overall, significantly fewer patients reported bloating in the CO ₂ group ( P = 0.0012). However, we observed only a trend to lower post-interventional pain ( P = 0.15) and a lower pain score. There was no significant difference in transcutaneous pCO ₂ level and no adverse events occurred. Although there was no difference in the dosage of propofol and midazolam, we observed a significant increased necessity for use of synthetic opioids in the RA group to achieve optimal examination conditions ( P = 0.023). Conclusions The benefits using CO ₂ in colonoscopy of deeply sedated children predominate. In particular, CO ₂ insufflation may allow a less painful post-interventional time and it significantly reduces abdominal bloating. Moreover, with CO ₂ , significantly less additional opioids were used. Thus, CO ₂ insufflation can be considered as safe in deeply sedated patients as there was no relevant pulmonary CO ₂ retention observed. (DRKS00013914).

Fig. 1

Study flow diagram.

Supplemental Fig. 1

Visual analogue scale (VAS). We used a 10-point visual analogue scale combining numerical rating scales from zero (= no pain) to ten points (maximal pain as worse as it could be), a colored analog scale from blue to red and a face pain scale (scored 0, 2, 4, 6, 8, 10) to quantify age appropriate pain perception.

Fig. 2

Interventional-related pain sensation . Mean values for pain assessed by an age-appropriate combination of a 10-point visual analogue scale (VAS) (0 = no pain, 10 = maximum imaginable pain), a numerical rating scale, a colored analog scale and a face pain scale at the time points 15 minutes, 60 minutes, 3 hours and 24 hours after colonoscopy according to type of gas are indicated (mean carbon dioxide group (blue), mean room air group (green).

Supplemental Fig. 2

Abdominal girth 5 min and 60 min after colonoscopy. Difference of the abdominal girth (cm) of both methods compared in mean values ± standard deviation. Carbon dioxide (blue) and room air (green) 5 minutes ( P  = 0.59; not significant) and 60 minutes after colonoscopy ( P  = 0.4; not significant)

Supplemental Fig. 3

Propofol and Midazolam dosage during the examination. Dosage of propofol and midazolam in mean values ± standard deviation (mg/kg body weight) comparing patients receiving carbon dioxide (blue) or room air (green).

Fig. 3

Maximum p _TC CO ₂ values during examination . Box and whisker plots of the maximum value of the p _TC CO ₂ (in mmHg) during the examination, separated into the different types of gas. The whiskers indicate the 5 % and 95 % quantile (x), the median is symbolized by a -, the maximum or the minimum by a + ( P  = 0.27).