Capnography facilitates tight control of ventilation during transport

Objective: We tested the hypothesis that Paco(2) would be more tightly controlled if end-tidal CO2 monitoring was used during hand ventilation for transport of intubated patients. Design: Randomized, prospective analysis of the no monitor and monitor-blind groups (the monitor was on the bed during transport but only the investigator was aware of the end-tidal CO2 values). Nonrandomized, prospective analysis of the monitor group (ventilation controlled using end tidal CO2 value from monitor). Setting: University hospital operating room and intensive care unit (ICU). Patients: Fifty intubated patients who were transported from the operating room to the ICU or from the CU to the neuroradiology suite were assigned randomly to one of two groups: a) no monitor group (n = 25); and b) monitor-blind group (n = 25). An additional group (monitor group, n = 10) was subsequently added to the study. Interventions: Capnography was instituted in all patients in a blocked fashion. Measurements and Main Results: Arterial blood gases and end-tidal CO2 values were measured before and after transport. When comparing overall group data, pre- and post-Paco(2) values were similar: monitor 39 +/- 2 vs. 41 +/- 2 torr (5.2 +/- 0.3 vs. 5.5 +/- 0.3 kPa); monitor-blind 39 +/- 1 vs. 39 +/- torr (5.2 +/- 0.1 vs. 5.2 +/- 0.3 kPa); no-monitor 39 +/- 1 vs. 37 +/- torr (5.2 +/- 0.1 vs. 5.0 +/- 0.1 kPa). However, when comparing Paco(2) values for individual patients, we found that there was significantly greater variability for Paco(2) after transport when end tidal CO2 was not used for control of ventilation during transport. Conclusions: These data do not support routine monitoring of end-tidal CO2 during short transport times in adult patients requiring mechanical ventilation. However, the monitor may prevent morbidity in patients requiring tight control of Paco(2).