PT  - JOURNAL ARTICLE
AU  - Ulla Møller Weinreich
AU  - Beata Rychwicka-Kielek
AU  - Bjarne Andersen
AU  - Rana Bibi
AU  - Lene Birket-Smith
AU  - Søren Risom Kristensen
AU  - Stephen Edward Rees
TI  - Mathematical arterialisation for monitoring during exacerbation
DP  - 2011 Sep 01
TA  - European Respiratory Journal
PG  - p558
VI  - 38
IP  - Suppl 55
4099  - http://erj.ersjournals.com/content/38/Suppl_55/p558.short
4100  - http://erj.ersjournals.com/content/38/Suppl_55/p558.full
SO  - Eur Respir J2011 Sep 01; 38
AB  - Repeated arterial puncture for acid-base and oxygenation status is painful, but quite common in COPD patients admitted for periods of exacerbation. Recently, a method has been presented (Rees, S.E. et. al. Comput. Methods Programs Biomed. 2006;81:18-25) for mathematically transforming values in peripheral venous blood to arterial, potentially eliminating the need for painful arterial puncture. This method has been evaluated at a single time point in COPD patients (Rees, S.E. et. al. Eur J Appl Physiol. 2010;108:483-94).The aim of this study was to evaluate the method in patients during the whole period of admission to the hospital for exacerbation.Twenty patients were studied over an admission of on average 5 days, with an average of 3 arterial blood samples taken during this period. For each arterial sample a paired peripheral venous sample was taken and used to calculate arterial values.Values of pH and arterial PCO2 calculated by the method compared well with those measured with a mean and standard deviation of the difference (measured minus calculated) of 0.000±0.010 pH and -0.03±0.26 kPa PCO2. Figure 1 illustrates the ability of the calculated values (squares, dashed) of arterial pH, PCO2 and PO2 to mirror measured clinical changes (open circles, solid) in a single patient studied on six consecutive days.Conclusions: The method may be a useful tool to evaluate COPD patients during admission without the need for repeated arterial punctures.