Sidestream end-tidal carbon dioxide monitoring during helicopter transport

Introduction: End-tidal carbon dioxide (EtCO₂) monitoring is standard of care for intubated patients. Sidestream technology also allows EtCO₂ monitoring in non-intubated patients. This is the first study to evaluate the feasibility of monitoring sidestream EtCO₂ on intubated and non-intubated patients during helicopter transport. Setting: An air medical transport program serving two level 1 trauma centers. Methods: In this prospective observational study, sidestream EtCO2 was monitored in 100 consecutive patients transported by helicopter. Flight nurses rated the difficulty posed by various factors of sidestream monitoring. An experienced flight nurse and a clinical engineer evaluated waveforms and EtCO₂ values. Results: Only 1 of the 100 transported patients required a change from sidestream to mainstream EtCO₂ monitoring. Moisture was noted in the tubing of two patients, and one was changed to mainstream. Eleven patients had occluded nares but were not changed to mainstream monitoring. On a 5-point Likert scale, responses to statements regarding difficulty with length of tubing, patient tolerance, and interference with patient care produced mean scores of 0.5 (range, 0-3). Responses regarding difficulty securing the cannula yielded a mean score of 0.7 (range, 0-3). Of 1,685 (99%) recorded EtCO₂ values, 1,668 met pre-established criteria for "consistent." Alveolar plateaus were identified in 81 of 94 (86%) patient waveforms by the flight nurse and 73 of 94 (78%) patient waveforms by the clinical engineer. Conclusion: Sidestream EtCO₂ monitoring is feasible during air medical transport of both intubated and non-intubated patients. The mechanism was easy to use, and consistent numeric values and waveforms with alveolar plateaus were obtained in a large majority of readings.