COMPARISON OF BLOOD GAS AND ACID-BASE MEASUREMENTS IN ARTERIAL AND VENOUS BLOOD SAMPLES IN PATIENTS WITH UREMIC ACIDOSIS AND DIABETIC KETOACIDOSIS IN THE EMERGENCY ROOM.

Gokel Y, et al. Am J Nephrol 2000 Jul-Aug;20(4):319-23.

BACKGROUND/AIMS: The aim of this study was to examine a plausible correlation between venous and arterial blood gas values in acidotic patients with chronic uremia or diabetic ketoacidosis (DKA).

METHODS: A total of 152 arterial and 152 venous blood samples from uremic patients (n = 100), DKA patients (n = 21) and healthy controls (n = 31) were analyzed for measurements of blood gas and acid-base status.

RESULTS: The means of arterial and venous pH, and arterial and venous HCO(-)(3) values for the uremic patients were 7. 17 +/- 0.14, 7.13 +/- 0.14, 10.13 +/- 4.26 and 11.86 +/- 4.23 mmol/l, respectively. The respective mean differences between arterial and venous pH values and arterial and venous HCO(-)(3) values were 0.04 +/- 0.02 and -1.72 +/- 0.42 mmol/l, respectively, for these patients. The means of the laboratory findings of DKA patients were arterial pH, 7.15 +/- 0.15; venous pH, 7.10 +/- 0.15; arterial HCO(-)(3), 8. 57 +/- 5.71 mmol/l and venous HCO(-)(3), 10.46 +/- 5.73 mmol/l. The respective mean differences between arterial and venous pH and arterial and venous HCO(-)(3) for this group were calculated to be 0. 05 +/- 0.01 and -1.88 +/- 0.41 mmol/l. In the healthy controls, the means of arterial and venous pH, and arterial and venous HCO(-)(3) values were 7.39 +/- 0.02, 7.34 +/- 0.02, 24.91 +/- 0.82 and 26.57 +/- 0.83 mmol/l, respectively. For the healthy controls the mean differences between the respective values in arterial and venous pH, and arterial and venous HCO(-)(3) were 0.05 +/- 0.01 and -1.66 +/- 0. 58 mmol/l. Although in healthy controls the correlation between arterial and venous pH values (r(2): 0.595) and arterial and venous HCO(-)(3) values (r(2): 0.552) were moderate, these correlations were significantly increased in both the acidotic patient group (r(2): 0.979 and 0.990) and the DKA group (r(2): 0.989 and 0.995).

CONCLUSION: A venous blood sample can be used to evaluate the acid-base status in uremic and DKA patients.

COMPARISON OF ARTERIAL AND VENOUS BLOOD GAS VALUES IN THE INITIAL EMERGENCY DEPARTMENT EVALUATION OF PATIENTS WITH DIABETIC KETOACIDOSIS.

Brandenburg MA, Dire DJ. Ann Emerg Med 1998 Apr;31(4):459-65.

STUDY OBJECTIVE: To determine whether venous blood gas values can replace arterial gas values in the initial emergency department evaluation of patients with suspected diabetic ketoacidosis.

METHODS: This prospective comparison was performed in an adult university teaching hospital ED. Samples for arterial and venous blood gas analysis were obtained during initial ED evaluations. The venous gas samples were collected with samples for other blood tests at the time of intravenous line insertion. Both arterial and venous samples were obtained before the initiation of treatment.

RESULT: Data from 44 episodes of diabetic ketoacidosis in 38 patients were analyzed. Laboratory findings of those patients with diabetic ketoacidosis were as follows (mean +/- SD): arterial pH, 7.20 +/- 14; venous pH, 7.17 +/- 13; serum glucose, 33.8 +/- 16 mmol/L (609 +/- 288 mg/dL); arterial HCO3-, 11.0 +/- 6.0 mmol; venous HCO3-, 12.8 +/- 5.5 mmol/L; serum CO2, 11.8 +/- 5.0 mmol/L; and anion gap, 26.7 +/- 7.6 mmol/L. The mean difference between arterial and venous pH values was 0.03 (range 0.0 to 0.11). Arterial and venous pH results (r = .9689) and arterial and venous HCO3- results (r = .9543) were highly correlated and showed a high measure of agreement.

CONCLUSION: Venous blood gas measurements accurately demonstrate the degree of acidosis of adult ED patients presenting with diabetic ketoacidosis.