Abstract
Background: Because arterial punctures are more painful, venous blood gas analysis
has been proposed as an alternative. Objectives: To determine if venous pCO2 can replace arterial pCO2 in emergency patients using a bedside blood gas analyzer. Methods: This is a cross-sectional
study. We recruited patients who were deemed by the attending Emergency Physicians
to require arterial blood gas analysis to determine their ventilation or acid-base
status. A venous and an arterial blood gas sample were drawn from the patient, temporally
as close to each other as possible. Both samples were then analyzed using the same
bedside blood gas analyzer immediately after collection. Results: There were 122 paired
samples obtained. The strength of the association between arterial and venous pCO2 is r = 0.838 (p = 0.001). The Bland-Altman bias plot methods for agreement show a mean difference
of 3.3 mm Hg with two standard deviation limits of agreement being −17.4 to 23.9;
93.4% of the pCO2 values fell within two standard deviation limits. Venous pCO2 below 30 mm Hg had a 100% (95% confidence interval [CI] 90.5–100) sensitivity and
100% (95% CI 80.7–100) Negative predictive value to rule out hypercarbia, defined
as arterial pCO2 > 45 mm Hg. Conclusions: There is significant variability in the arteriovenous difference
of pCO2 readings, hence, arterial punctures are still needed to specifically determine the
arterial pCO2.
Keywords
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References
- Pain during arterial puncture.Chest. 1996; 110: 1443-1445
- Comparison of arterial and venous blood gas values in the initial emergency department evaluation of patients with diabetic ketoacidosis.Ann Emerg Med. 1998; 31: 459-465
- Venous pH can safely replace arterial pH in the initial evaluation of patients in the emergency department.Emerg Med J. 2001; 18: 340-342
- Arterial blood gas results rarely influence emergency physician management of patients with suspected diabetic ketoacidosis.Acad Emerg Med. 2003; 10: 836-841
- Venous pCO2 and pH can be used to screen for significant hypercarbia in emergency patients with acute respiratory disease.J Emerg Med. 2002; 22: 15-19
- Correlation of simultaneously obtained capillary, venous, and arterial blood gases of patients in a paediatric intensive care unit.Arch Dis Child. 2004; 89: 176-180
- Validation of venous pCO2 to screen for arterial hypercarbia in patients with chronic obstructive airways disease.J Emerg Med. 2005; 28: 377-379
- Prediction of arterial blood gas values from venous blood gas values in patients with acute exacerbation of chronic obstructive pulmonary disease.Tohoku J Exp Med. 2006; 210: 285-290
- Can peripheral venous blood gases replace arterial blood gases in emergency department patients?.CJEM. 2002; 4: 7-15
- Comparison of arterial and venous blood gases analysis in patients with exacerbation of chronic obstructive pulmonary disease.Saudi Med J. 2007; 28: 862-865
- Agreement between bicarbonate measured on arterial and venous blood gases.Emerg Med Australas. 2004; 16: 407-409
- Clinical evaluation of i-STAT in the neonatal intensive care unit.Korean J Lab Med. 2004; 24: 166-172
- Errors in measuring blood gases in the intensive care unit: effect of delay in estimation.J Crit Care. 2003; 18: 31-37
- Sources of error in the pre-analytical phase of blood gas analysis [German].Praxis (Bern 1994). 1995; 84: 200-203
- Sequential changes of various parameters of arterial blood samples [Japanese].Masui. 2002; 51: 1352-1354
- Accuracy of the i-STAT bedside blood gas analyser.Eur Respir J. 1999; 14: 214-217
- The portable laboratory: an evaluation of the accuracy and reproducibility of i-STAT.Ann Clin Biochem. 1999; 36: 66-71
- Statistical methods for assessing agreement between two methods of clinical measurement.Lancet. 1986; 1: 307-310
- Comparing methods of measurement: why plotting difference against standard method is misleading.Lancet. 1995; 346: 1085-1087
- The accuracy of pulse oximetry in the emergency department.Am J Emerg Med. 2000; 18: 427-431
- Meta-analysis of arterial oxygen saturation monitoring by pulse oximetry in adults.Heart Lung. 1998; 27: 387-408
Article info
Publication history
Published online: October 20, 2008
Accepted:
April 20,
2008
Received in revised form:
March 27,
2008
Received:
February 7,
2008
Footnotes
Financial support was obtained from the National HealthCare Group Small Grant.
Identification
Copyright
© 2011 Published by Elsevier Inc.
