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
| Prospective | Mean difference in pH | - 0.03 | Small 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
| Prospective | Mean difference in pH | - 0.05 | Small 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
- 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.
- 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.