Capnography facilitates tight control of ventilation during transport

Objective: We tested the hypothesis that PaCO₂ 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 ICU to the neuroradiology suits 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 end Main Results: Arterial blood gases and end-tidal CO₂ values were measured before and after transport. When comparing overall group data, pre- and post. PaCO₂ 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 ± 2 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 PaCO₂ values for individual patients, we found that there was significantly greater variability for PaCO₂ 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 PaCO₂.