Measurement of end-tidal carbon dioxide in spontaneously breathing patients in the pre-hospital setting. A prospective evaluation of 350 patients.
OBJECTIVE
Monitoring of end-tidal carbon dioxide (EtCO(2)) is good clinical practice in the patient who is intubated and ventilated. This study investigated the EtCO(2) values in spontaneously breathing patients treated in a physician-staffed mobile intensive care unit (MICU). This article also discusses whether EtCO(2) monitoring may have an influence on therapeutic decisions by emergency physicians by providing additional information.


METHODS
Over a period of 6 months, 350 spontaneously breathing patients (162 males, 137 females) were treated and transported in our MICU and monitored using a LifePak 12 monitor (EtCO(2), respiratory rate, pO(2), blood pressure, heart rate). Only 299 were enrolled in the study.


RESULTS
Pathological EtCO(2) values were detected in 19 patients (6.3%). EtCO(2) levels of >55 mmHg (7.3 kPa) were found in nine of 12 (75%) patients with asthma, in one of 23 patients with hypoglycaemia (4.3%), and in all patients with subarachnoid hemorrhage, acute seizures and drug intoxications. With the exception of the asthma patients, all patients had an initial Glasgow Coma Score <8. EtCO(2) levels <20 mmHg (2.7 kPa) were found in all patients with hyperventilation or shock due to volume deficiency. Errors in EtCO(2) measurement occurred in 5% of cases.


CONCLUSIONS
Although EtCO(2) monitoring may be a useful additional variable in spontaneously breathing patients. Consideration of the respective disease and the cost to benefit ratio suggests that this method should only be used for selected indications.
Wahlen
B M
BM
Clinic for Anesthesiology, Johannes Gutenberg-University of Mainz, Langenbeckstrasse 1, 55101, Mainz, Germany.
Bey
T
T
Wolke
B B
BB
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000552:Ambulances; D001249:Asthma / Q000175:diagnosis; D002245:Carbon Dioxide / Q000032:analysis*; D004632:Emergency Medical Services; D005260:Female; D006801:Humans; D007003:Hypoglycemia / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D009294:Narcotics / Q000506:poisoning; D011446:Prospective Studies; D012640:Seizures / Q000175:diagnosis; D013345:Subarachnoid Hemorrhage / Q000175:diagnosis
D009294:Narcotics; D002245:Carbon Dioxide