مقاربة غازات الدم الشرياني (القلاء الاستقلابي-1)

1. ABG series ANAS SAHLE , MD DAMASCUSE HOSPITAL

2. Acid-Base Disorders and the ABG 4

3. Very important note: Sodium should be corrected if glucose is high befor calculated AG REF:high-yield(c):2007

4. BREIF PREVIEW

5. Summary of the Approach to ABGs Check the pH Check the pCO2 Select the appropriate compensation formula Determine if compensation is appropriate Check the anion gap AG=NA – (HCO3 + CL):12±4 If the anion gap is elevated, check the delta-delta G:G Ratio =Δ AG (12-AG) HCO3 (24-HCO3) If a metabolic acidosis is present, check urine pH Generate a differential diagnosis

6. EXPECTED CHANGES IN ACID-BASE DISORDERS From: THE ICU BOOK - 2nd Ed. (1998) [Corrected]

8. Gap:gap ratio??

9. HIGH AG M.AC Osmolal gap = measured serum osmolality - (2 NA + gluco8 + bun,8) Corrected osmolal gap = measured serum osmolality - (2 NA + gluco8 + bun,8 + ETOH,6)

10. HIGH AG M.AC High normal

11. Expected PCO2 : Measured PCO2

12. YES NO YES NO YES NO YES NO

13. <5,5 >5,5 Urine AG = (UNA +UK) - UCL

14. METABOLIC ALKALOSIS-1

16. Vomiting

17. Exogenous alkali

18. Hyper- aldosteronism

20. < 20 mEq > 20 mEq HIGH NORMAL

21. Case: 1 An elderly woman from a nursing home was transferred to hospital because of profound weakness and areflexia. Her oral intake had been poor for a few days. Current medication was a sleeping tablet which was administered by nursing staff as needed.

22. LAB

27. YES NO YES NO YES NO YES NO YES NO

28. CASE: 3 46 year old man with progressive CKD on conservative management (baseline BUN 40, Creat 4.0) is admitted after episode of vomiting attributed to food poisoning. He is orthostatic on exam and appears “dehydrated” Nephrology called to dialyze Renal fellow: Why’s his HCO3 so high? Resident: High? It’s 25, and the pH is 7.40. Now come in and dialyze him!

29. CRF>>>>>>>HIGH AG M.AC VOMITING>>>>>>>METABOLIC ALKALOSIS FROM tow above disorders / we can explanation why PH,HCO3 in normal limites? Thereby we should calculate AG in all cases

30. MIXED DISORDERS(PH:NORMAL)

31. AG

32. CASE:4 45 year old woman with long history of EtOH abuse comes into ED with 3 days of nausea and vomiting. She lives on the streets and is very disgeveled appearing. She stopped drinking 3 days ago because she felt sick

33. LAB: Measured osmolal serum=284

34. What it etiology for each disorders

35. HIGH AG M.AC Osmolal gap = measured serum osmolality - (2 NA + gluco8 + bun,8) Corrected osmolal gap = measured serum osmolality - (2 NA + gluco8 + bun,8 + ETOH,6)

36. Discussion Osmolal GAP = 10 Normal osmolal gap. Is there CRF?. IS THERE KETON? IS BLOOD GLUCOSE HIGH?. What is diagnosis?

37. HIGH AG M.AC

38. Diagnosis Alkoholicketoacidosis

39. NEXT LECTURE Metabolic alkalosis-2 Cases