title: Measurement of oxygen consumption in children undergoing cardiac catheterization: comparison between mass spectrometry and the breath-by-breath method.
abstract: Accurate measurement of oxygen consumption (VO2) is important to precise calculation of blood flow using the Fick equation. This study aimed to validate the breath-by-breath method (BBBM) of measuring oxygen consumption VO2 compared with respiratory mass spectroscopy (MS) for intubated children during cardiac catheterization. The study used MS and BBBM to measure VO2 continuously and simultaneously for 10 min in consecutive anesthetized children undergoing cardiac catheterization who were intubated with a cuffed endotracheal tube, ventilated mechanically, and hemodynamically stable, with normal body temperature. From 26 patients, 520 data points were obtained. The mean VO2 was 94.5 ml/min (95 % confidence interval [CI] 65.7-123.3 ml/min) as measured by MS and 91.4 ml/min (95 % CI 64.9-117.9 ml/min) as measured by BBBM. The mean difference in VO2 measurements between MS and BBBM (3.1 ml/min; 95 % CI -1.7 to +7.9 ml/min) was not significant (p = 0.19). The MS and BBBM VO2 measurements were highly correlated (R (2) = 0.98; P < 0.0001). Bland-Altman analysis showed good correspondence between MS and BBBM, with a mean difference of -3.01 and 95 % limits of agreement ranging from -26.2 to +20.0. The mean VO2 indexed to body surface area did not differ significantly between MS and BBBM (3.4 ml/min m(2); 95 % CI -1.4 to 8.2; p = 0.162). The mean difference and limits of agreement were -3.8 ml/min m(2) (range, -19.9 to 26.7). Both MS and BBBM may be used to measure VO2 in anesthetized intubated children undergoing cardiac catheterization. The two methods demonstrated excellent agreement. However, BBBM may be more suited to clinical use with children.
authors.affiliation: Pediatric Cardiology, Stollery Children's Hospital, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, AB, Canada.
authors.forename: Long
authors.initials: L
authors.lastname: Guo
authors.forename: Yong
authors.initials: Y
authors.lastname: Cui
authors.forename: Scott
authors.initials: S
authors.lastname: Pharis
authors.forename: Mark
authors.initials: M
authors.lastname: Walsh
authors.forename: Joseph
authors.initials: J
authors.lastname: Atallah
authors.forename: Meng-Wei
authors.initials: MW
authors.lastname: Tan
authors.forename: Jennifer
authors.initials: J
authors.lastname: Rutledge
authors.forename: J Y
authors.initials: JY
authors.lastname: Coe
authors.forename: Ian
authors.initials: I
authors.lastname: Adatia
mesh_terms: D000293:Adolescent; D001784:Blood Gas Analysis / Q000379:methods*; D006328:Cardiac Catheterization; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D010101:Oxygen Consumption / Q000502:physiology*; D012121:Respiration, Artificial