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Venous blood gas in adult patients with diabetic ketoacidosis

Three Part Question

In [an adult patient with diabetic ketoacidosis] do [venous blood gases] accurately demonstrate [the degree of acidosis]?

Clinical Scenario

A 22 year old insulin dependant diabetic presents to our emergency department with a raised blood sugar and urine dipstick showing +++ of ketones. You suspect diabetic ketoacidosis and would like the know the degree of his acidosis, but the patient refuses arterial blood gas sampling due to a previous bad experience. You wonder whether venous blood would accurately show the degree of his metabolic acidosis.

Search Strategy

Medline 1966-04/03 using the OVID interface.
[(venous blood.mp OR exp blood specimen collection OR exp blood gas analysis) AND (exp diabetic ketoacidosis OR diabetic ketoacidosis.mp OR exp diabetic coma) AND (exp acidosis OR acidosis.mp OR exp hydrogen-ion concentration)] AND LIMIT to human AND English language.

Search Outcome

Altogether 27 papers were found of which only 2 are relevant and of sufficient quality for inclusion.

Relevant Paper(s)

Author, date and country Patient group Study type (level of evidence) Outcomes Key results Study Weaknesses
Brandenburg MA & Dire DJ,
1998,
USA
38 patients with DKA presented to emergency department Venous vs arterial pH ProspectiveMean difference in pH- 0.03Small numbers No control group
Gokel Y et al,
2000,
Turkey
152 samples from 100 - uremic patients 21 patients with DKA and 31 healthy volunteers Venous vs arterial pH ProspectiveMean difference in pH- 0.05Small numbers Unequal number of patients in each group

Comment(s)

There are only a limited number of studies on this subject and these have involved small numbers of patients. Further studies with large series of patients are necessary.

Clinical Bottom Line

There is no clinically significant difference between arterial and venous pH estimates in patients with diabetic ketoacidosis.

References

  1. Brandenburg MA, Dire DJ. Comparison of Arterial and venous blood gases in the initial emergency department evaluation of patients with diabetic ketoacidosis. Ann Emerg Med 1998;31(4);459-465.
  2. Gokel Y, Paydas S, Koseoglu Z, et al. Comparison of blood gases and acid-base measurements in arterial and venous blood samples in patients with uremic acidosis and diabetic ketoacidosis in the emergency room. Am J Nephrol 2000;20(4):319-323.