Noninvasive monitoring capnometry for continuous monitoring of metabolic status in pediatric diabetic ketoacidosis (DKA)

Purpose

Patients with diabetic ketoacidosis (DKA) have complex metabolic abnormalities and manifest a low pCO₂ as result of respiratory compensation. During treatment, as venous pH improves, respiratory rate (RR) decreases causing an increase in pCO₂. To determine the reliability and clinical value of continous ETCO₂ by oral/nasal capnometry for monitoring the metabolic status of the pediatric DKA patient.

Design/setting

Prospective observational study, university affiliated children's hospital E/R.

Materials and methods

Patients with pH of 7.33 or less with evidence of hyperglycemia, ketosis and between the age of 1 year to 18 years of age were enrolled. ETCO₂ measurements was obtained by continuous oral/nasal side stream capnometry and vital signs were recorded every 15 min. Venous blood gases analyses were obtained every 1–2 hours with simultaneous recorded ETCO₂, (RR). ETCO₂ measurements were compared with venous pCO₂ and changes in respiratory rates.

Results

A total of 121 patients were monitored for a mean of 5.9 hours. Age ranged from 1.8 to 18 years, mean of 10.9 ± 5.2 years. Patient disposition were admitted to PICU or Wards or discharged to home.

ETCO₂ correlated with pCO₂R = 0.92 P = 0.0001, pH R = 0.88 P = 0.0001 and inversely correlated with respiratory rate R = -0.79 P = 0.0001. The concordance correlation for first (R = 0.93 P = 0.0001), last (R = 0.60 P = 0.0001) and all (R = 0.92 P = 0.0001) observation between ETCO₂ and pCO₂ were significant.

Conculsion

Dependable noninvasive continuous ETCO2 monitoring can be obtained using oral/nasal capnometry circuits and reflect metabolic changes in the pediatric DKA patient. We have demonstrated that continous end-tidal CO₂ monitoring can be used as a nonivasive assessment of the metabolic status of the pediatric patient in DKA.

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