ISSN:
1432-1238
Keywords:
Oxygen consumption
;
Carbon dioxide
;
Pediatric
;
Indirect calorimetry
;
Energy expenditure
;
Mechanical ventilation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Objective A paediatric option for the measurement of $$\dot VO_2$$ and $$\dot VCO_2$$ (20 to 150 ml/min) has recently been introduced for the adult Deltatrac metabolic monitor (Datex Instrumentarium, Finland) to use in ventilated and spontaneously breathing children. This paper describes a laboratory validation of the paediatric option for ventilated children with regard to the influence of respiratory variables. Design Respiratory variables were varied within the following ranges: FIO2 0.21–0.8, $$\overline {FEO_2 }$$ (DFO2) 0.01–0.05, $$\overline {FECO_2 } 0.01 - 0.05,\dot V_E 300 - 6000ml/\min$$ , VT 8–300 ml, RR 10–50/min, Paw 10–60 mbar, relative humidity 10% and 60%, and resulted in 107 test situations. Setting Gas exchange was simulated by injection of nitrogen and CO2 at a RQ close to 1. Patients or participants Different situations of paediatric patients ventilated in controlled mode were simulated on a gas injection model. Interventions Respiratory and metabolic variables were varied independently to result in a range of 8 to 210 ml/min of $$\dot VO_2$$ and $$\dot VCO_2$$ . Measurements and results Reference measurements were carried out by mass spectrometry and wet gas spirometry. The mean $$\dot VCO_2$$ difference for all tests ranging from 20 ml/min to 210 ml/min was −2.4% (2SD=±12%). The respective $$\dot VO_2$$ difference was −3.2% (2SD=±23%). Measurement agreement for $$\dot VO_2$$ in neonatal respirator treatment (20–50 ml/min) compared to older children (50–210 ml/min) showed a mean difference of −3.9% (2SD=±26%) versus −2.8% (2SD=±20%). The respective differences for $$\dot VCO_2$$ were −7.1% (2SD=±7%) versus +0.4% (2SD=±10%). The mean difference for $$\dot VO_2$$ as well as $$\dot VCO_2$$ indicated a high systematic agreement of both methods. The variability (±2SD) in $$\dot VCO_2$$ measurement is acceptable for all applications. The overall variability in $$\dot VO_2$$ measurement (2SD=±23%) can be reduced by exclusion of all tests with a $${FECO_2 }$$ and DFO2 below 0.03. This results in a mean difference of −3.2% (2SD=±13.7%). Conclusion Within this limitation the paediatric measurement option seems to introduce a valuable method for clinical application in paediatric intensive care medicine.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02425058
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