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.
Similar content being viewed by others
References
Rieke H, Weyland A, Hoeft A, Weyland W, Sonntag H, Breme S (1990) Kontinuierliche HZV-Messung nach dem Fickschen Prinzip in der Kardioanaesthesie. Anaesthesist 39:13–21
Raemer DB, Westenskow DR, Gehmlich DK, Richardson CP, Jordan WS (1979) A method for measurement of oxygen uptake in neonates. J Appl Physiol 46:1200–1204
Mayfield SR (1991) Technical and clinical testing of a computerized indirect calorimeter for use in mechanically ventilated neonates. Am J Clin Nutr 54:30–34
Fixler DE, Carrell T, Brown R, Willis K, Miller WW (1974) Oxygen consumption in infants and children during cardiac catheterization under different sedation regimens. Circulation 50:788–794
Lister G, Hoffman JIE, Rudolph AM (1974) Oxygen uptake in infants and children: A simple method of measurement. Pediatrics 53:656–662
Marks KH, Coen P, Kerrigan JR, Francalancia NA, Nardis EE, Snider MT (1987) The accuracy and precision of an open-circuit system to measure oxygen consumption and carbon dioxide production in neonates. Pediatr Res 21:58–65
Meriläinen PT (1987) Metabolic monitor. Int J Clin Monit Comput 4:167–177
Braun U, Zundel J, Freiboth K, Weyland W, Turner E, Heidelmeyer CF, Hellige G (1989) Evaluation of methods for indirect calorimetry with a ventilated lung model. Intensive Care Med 15:196–202
Bland JM, Altman DG (1986) Statistical methods for assessing agreement between two methods of clinical measurement. Lancet I:307–310
LaMantia KR, O'Connor T, Barash PG (1990) Comparing methods of measurements: an alternative approach. Anesthesiology 72:781–783
Ultman JS, Bursztein S (1981) Analysis of error in the determination of respiratory gas exchange at varying FIO2. J Appl Physiol 50:210–216
Svensson KL, Sonander HG, Stenqvist O (1990) Validation of a system for measurement of metabolic gas exchange during anaesthesia with controlled ventilation in an oxygen consuming lung model. Br J Anaesth 64:311–319
Young BA, Fenton TW, Mclean JA (1984) Calibration methods in respiratory calorimetry. J Appl Physiol 56:1120–1125
Weyland W, van der Horst J, Weyland A, Reiter M, Freiboth K; Braun U (1992) Validierung der Gasaustausch Monitoringfunktion des Engström-Elvira-Beatmungsgeräts. Anaesthesist 41:210–217
Makita K, Nunn JF, Royston B (1990) Evaluation of metabolic measuring instruments for use in critical ill patients. Crit Care Med 18:638–644
Takala J, Kainänen O, Väisänen P, Kari A (1989) Measurement of gas exchange in intensiv care: laboratory and clinical validation of a new device. Crit Care Med 17:1041–1047
Weissman C, Sardar A, Kemper M (1990) In vitro evaluation of a compact metabolic measurement instrument. J Parenter Enteral Nutr 14:216–221
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Weyland, W., Weyland, A., Fritz, U. et al. A new paediatric metabolic monitor. Intensive Care Med 20, 51–57 (1994). https://doi.org/10.1007/BF02425058
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02425058