Agreement between bicarbonate measured on arterial and venous blood gases

Abstract

Venous bicarbonate estimation shows a high level of agreement with the arterial value, with acceptably narrow 95% limits of agreement. These results suggest that venous bicarbonate estimation may be an acceptable substitute for arterial measurement.

Agreement between Central Venous and Arterial Blood Gas Measurements in the Intensive Care Unit

“…Nonetheless, that the patient population in the study had a predominance of patients with sepsis does limit the generalizability of our results, especially in patients with very low cardiac output. Third, the study did use central venous samples obtained from a central line, not peripheral venous samples; however, given that our study found acceptable agreement between arterial and central venous values, it would be expected that similar agreement would be found if peripheral venous samples were used, which in fact has been confirmed by both our own results and those of other studies (7)(8)(9)(10)(12)(13)(14)(15) …”

“…A number of studies have suggested that there is agreement between ABG and VBG values, although most of the previous studies were limited by specific patient group samples (e.g., patients with diabetic ketoacidosis), analysis of only one or some parameters rather than all commonly used parameters (e.g., pH, Pco 2 , and bicarbonate), or examination of only one ABG and VBG sample per patient (7)(8)(9)(10)(11)(12)(13)(14)(15). A few authors even expressed doubts about the use of VBG values in lieu of arterial values (4 -6).…”

“…Venous blood gas (VBG) analysis requires fewer punctures, is a relatively safer procedure for both the patient and the health care provider, and may be an alternative to ABG analysis for acid-base status. Although a few studies have expressed reservations regarding the accuracy of VBG values (4 -6), there is emerging evidence to suggest that there is agreement between ABG and VBG values (7)(8)(9)(10)(11)(12)(13)(14)(15). To our knowledge, no previous study has examined the agreement among all of the commonly used parameters in arterial and central VBG samples in a diverse population of medical intensive care unit (ICU) patients.…”

Effects of Mean Arterial Pressure and Needle Size on Arterial Sampler Filling Time

“…2 Although the pH and bicarbonate of venous blood have been shown to correlate well with the pH and bicarbonate of arterial blood, and may be used to identify patients with extreme hypercarbia, an arterial blood sample is necessary for assessing oxygenation and monitoring ventilation. [7][8][9] Although clinical practice guidelines suggest that blood color and pulsatile blood flow can verify a successful arterial puncture, those are subjective indicators, whereas sampler filling time is an objective indicator and may be more reliable in clinical practice. Lower blood pressures increased sampler filling times, and the longest average filling time was 20.5 s with a mean arterial pressure of 57 mm Hg.…”

Comparison of measured Serum Total Carbon Dioxide with calculated Bicarbonate calculated from Arterial Blood Gas Analysis

“…These theoretical reasons in themselves amount to approximately 2.0 mmol/L difference between calculated and measured bicarbonate. [10][11][12] The first step in assessing agreement between measured and calculated bicarbonate by correlation coefficient showed a good correlation with r = 0.950 with p < 0.05. The correlation coefficient to assess the agreement depends not only on the correlation coefficient, but also on the range of values, so a wide range of values will show a good correlation even if the values are in poor agreement.…”