End-tidal carbon dioxide measurement in infants and children during and after general anaesthesia.
We have examined the reliability of end-tidal carbon dioxide (PetCO2) monitoring as an estimate of arterial carbon dioxide tension (PaCO2) in spontaneously breathing infants and children. Forty patients were studied in the post-anaesthetic care unit; 20 < 12 kg and 20 > or = 12 kg. The PetCO2 was sampled via a 5 cm 16 gauge catheter taped below an external naris and this measurement was compared with the PaCO2 of a sample drawn from an indwelling arterial line. Twenty additional patients were studied during inhalational anaesthesia. The PetCO2 was measured both from the proximal end of the elbow connector and from a 5 cm cannula inserted through the elbow. An arterial blood gas sample was obtained simultaneously. The arterial to end-tidal (Pa-et) differences were compared between the two sites. Patients studied in the post-anaesthetic care unit showed good correlation between PetCO2 and PaCO2 regardless of weight: Pa-etCO2 of -0.6 +/- 3.6 (< 12 kg) and -1.1 +/- 2.8 mmHg (> or = 12 kg). Patients studied during mask anaesthesia showed better correlation between PetCO2 and PaCO2 when PetCO2 was sampled from the cannula: Pa-etCO2 of 3.5 +/- 4.8 mmHg (cannula), 8.6 +/- 4.5 (elbow) (P < 0.05). These results suggest that end-tidal CO2 monitoring is a useful and reliable method for assessing adequacy of ventilation in spontaneously breathing children weighing between 5.2 and 35 kg.
Campbell
F A
FA
Department of Anaesthesia, Hospital for Sick Children, University of Toronto, Ontario, Canada.
McLeod
M E
ME
Bissonnette
B
B
Swartz
J S
JS
D000762:Anesthesia Recovery Period; D000769:Anesthesia, Inhalation; D002245:Carbon Dioxide / Q000032:analysis* / Q000097:blood; D002648:Child; D002675:Child, Preschool; D006221:Halothane / Q000008:administration & dosage; D006801:Humans; D007223:Infant; D008991:Monitoring, Physiologic; D009609:Nitrous Oxide / Q000008:administration & dosage; D010100:Oxygen / Q000008:administration & dosage / Q000097:blood; D012119:Respiration; D013990:Tidal Volume
D002245:Carbon Dioxide; D009609:Nitrous Oxide; D010100:Oxygen; D006221:Halothane