The utility of the pretracheal stethoscope in detecting ventilatory abnormalities during propofol sedation in children.
Monitoring of ventilation with capnography or a stethoscope is recommended because the detection of ventilatory abnormalities can be significantly delayed by the use of pulse oximetry alone in patients receiving supplemental oxygen. The aim of this study was to evaluate the diagnostic performance of the pretracheal stethoscope with pulse oximetry and capnography in detecting adverse respiratory events during propofol sedation in nonintubated children. We hypothesized that use of the pretracheal stethoscope would facilitate earlier detection of adverse respiratory events.
This was a prospective observational study of children undergoing procedural sedation at a pediatric sedation program. A pretracheal stethoscope, pulse oximetry, and nasal capnography were attached at the discretion of the sedation nurse and provider to monitor ventilation.
We enrolled 104 patient encounters (mean recorded time, SD 8.3 ± 5.3 minutes) from February, 2015 to March, 2017. The pretracheal stethoscope was the first monitor to detect adverse events in 64% (25/39) of patients compared to 18% (7/39) for capnography and 15% (6/39) for pulse oximetry. Auscultation performed best at detecting upper airway obstruction but capnography and pulse oximetry performed best at detecting hypoventilation. The positive predictive value for detecting a true ventilation abnormality and 95% CI of the pretracheal stethoscope, pulse oximetry, and capnography was 100% (90%-100%), 18% (10%-31%), and 27% (18%-38%), respectively. The negative predictive value and 95% CI of the pretracheal stethoscope, pulse oximetry, and capnography was 88% (82%-92%), 68% (59%-75%), and 70% (61%-78%), respectively. Limitations are short observation time, nonstandardized application of respiratory monitors, and too much focus on auscultation.
A pretracheal stethoscope in conjunction with capnography and pulse oximetry detects most sedation-related adverse events first. Auscultation performed best at detecting upper airway obstruction but capnography and pulse oximetry performed best at detecting hypoventilation.