EVALUATION OF A PORTABLE INFRARED END-TIDAL CARBON-DIOXIDE MONITOR DURING PEDIATRIC INTERHOSPITAL TRANSPORT

Purpose. Critically ill children often require endotracheal intubation before transport to a tertiary care center. Correct endotracheal tube (ETT) placement (trachea versus esophagus) and maintenance during tra nsport are of the utmost importance. We evaluated a portable, qualitat ive, infrared end-tidal carbon dioxide monitor during transport of cri tically ill children. Methods. Fifty patients, ages 1 day to 19 years (median, 1 year), weighing 1.6 to 70 kg (median, 10 kg) who were intub ated and transported by ground ambulance (n = 25) or rotorcraft (n = 2 5) were enrolled. ETT position was confirmed by physical examination, arterial blood gas or pulse oximetry, and sometimes by a chest radiogr aph. The instrument was attached, and readings were obtained before an d during transport by transport nurses or respiratory therapists who a lso completed a brief questionnaire about the monitor. A moving bar in dicator with a light-emitting diode display on the instrument indicate s the presence of expired carbon dioxide. Results. All three esophagea l tube positions and 48 of 50 tracheal tube positions were correctly i dentified (sensitivity, 96%; specificity, 100%; positive predictive va lue, 100%; and negative predictive value, 60%). There were two false-n egative results: in one case, there was instrument malfunction because of blood backing up into the tubing because of traumatic intubation, and in the second case, the patient had a chest tube that was leaking air. The device was evaluated as ''too large'' (30 of 50), ''hard to s ecure'' (25 of 50), and ''not convenient'' (29 of 50). Tube kinking wa s a problem (n = 7) when used in small infants in isolettes. The instr ument was considered helpful in assuring ETT position when clinical ev aluation was not possible because of noisy conditions. Conclusions. We conclude that this carbon dioxide monitor was useful during transport of critically ill children in confirming ETT position. Further improv ements in this noninvasive technology might be helpful in making the d evice more practical for use during interhospital transport.