CAPNOGRAPHY DETECTS SUB‐CLINICAL ALTERED RESPIRATORY EVENTS NOT DETECTED BY ROUTINE MONITORING IN CHILDREN UNDERGOING EGD WITH PROCEDURAL SEDATION

Abstract

Introduction: Capnography measures and displays in continuous waveform exhaled carbon dioxide concentration. Microstream capnography (mCAP) is a non-invasive method of capnography using a modified oxygen nasal cannula. This study compares the effectiveness of mCAP and conventional monitoring in detecting respiratory changes for pediatric patients undergoing EGD with deep sedation. Methods: The authors completed a prospective observational study. Altered Respiratory Events (AREs) were defined as any abnormality in mCAP waveform for >15 seconds or if events were associated with esophageal intubation/extubation. An independent clinician observed for any clinical changes and interventions, and recorded data collected by conventional monitoring (Pulse oximetry [POX], vital signs) and mCAP. Results: Forty four patients (M:F = 22:22, mean age 8.8 years) were enrolled. Patients were premedicated with 0.01 mg/kg of atropine and given an average of 0.16 mg/kg of versed and 1.6 mg/kg of ketamine. A total of 179 AREs were documented. All 179 AREs were detected by mCAP while POX detected 15 AREs. Of the 15 AREs detected by POX, 14 were detected by mCAP on average 15 seconds earlier. Two hundred and five identifiable clinical changes were associated with 168 of the AREs (78 esophageal intubation/extubation, 80 gag, 14 cough, 18 agitation, 2 breath holding, 13 procedure related), while 11 AREs had no clinical change. Eighty six interventions were required as a consequence of AREs (10 increased oxygen, 34 suction, 28 additional sedation, 12 withdrawl of endoscope, 2 reposition). Conclusions: Sub-clinical AREs are common in children undergoing EGD with deep sedation. The majority of these AREs are detected by mCAP but not by conventional monitoring. Most of these sub-clinical AREs are associated with identifiable clinical changes. The use of mCAP with conventional monitoring and POX increases the sensitivity of monitoring in children undergoing procedure related sedation.