1. نفرولوژیست استادیار دانشکده پزشکی
دکتر عبدالامیر عطاپور
نفرولوژیست
استادیار دانشکده پزشکی

2. CASE STUDY 1 32 years of age a female patient Medications Hypertension
Asthma
Medications
Albuterol
Atenolol
Hydrochlorothiazide

3. Admitted for exacerbation of asthma secondary to bronchitis Treated
Albuterol treatments every 3 hours
Cephalosporin antibiotic
Prednisone taper
Her Atenolol is stopped

4. After 24 hours severe muscle cramps
Her admission potassium level was 3.9 mEq/L
A basic metabolic profile reveals normal renal function and a potassium level of 2.9 mEq/L

5. What do will do ? Kcl orally? 20 mEq/L K in NS ? 20 mEq/L k in DW ?
20 mEq/L in manitol ?
6 mEq/L direct IV ?

6. 40 mEq of potassium immediately
prescribed 40 mEq twice daily with close monitoring of her level.

7. Causes of hypokalemia DECREASED POTASSIUM INTAKE
INCREASED ENTRY INTO CELLS
INCREASED GASTROINTESTINAL LOSSES
INCREASED URINARY LOSSES  

8. DECREASED POTASSIUM INTAKE
 Potassium intake is normally 40 to 120 meq per day
In the presence of potassium depletion
The kidney is able to lower potassium excretion to a minimum of 5 to 25 meq per day

9. INCREASED ENTRY INTO CELLS
More than 98 percent of total body potassium is intracellular
Increased availability of insulin 
Elevated beta-adrenergic activity
Endogenous catecholamines
Acting via beta-2 adrenergic receptors Na-K-ATPase pump and the Na-K-2Cl (NKCC1) cotransporter possibly
Increasing the release of insulin

10. Elevation in extracellular pH
The serum potassium concentration falls by less than 0.4 meq/L for every 0.1 unit rise in pH
Organic acid
Inorganic acid

11. Hypokalemic periodic paralysis
Reduce the serum potassium to as low as 1.5 to 2.5 meq/L, are often precipitated by rest after exercise, stress, or a carbohydrate meal.

12. Increased blood cell production Hypothermia
Vit B12 & Folate
Hypothermia 
Drive potassium into the Barium intoxication — 
Ingestion of contaminated food or from a suicide attempt
Cesium intoxication
For cancer, can be associated with hypokalemia

13. Chloroquine intoxication Antipsychotic drugs
 Hypokalemia is a rare complication of therapy with selected antipsychotic drugs
Risperidone 
Quetiapine

14. INCREASED GASTROINTESTINAL LOSSES
Upper gastrointestinal losses 
The concentration of potassium in gastric secretions is only 5 to 10 meq/L
Lower gastrointestinal losses 
the potassium concentration in lower intestinal losses is relatively high (20 to 50 meq/L)

15. INCREASED URINARY LOSSES
Increased mineralocorticoid activity
Increased distal delivery of sodium and

16. Major causes of urinary potassium wasting
The most common causes of hypokalemia due to urinary potassium losses include
Diuretic
Primary increase in mineralocorticoid activity
Increased distal delivery of nonreabsorbable anions
Loss of gastric secretions

17. Non reabsorbable anions
Bicarbonate
Beta-hydroxybutyrate in diabetic ketoacidosis
Hippurate following toluene use (glue-sniffing)
Penicillin derivative in patients receiving high-dose penicillin therapy

18. Less common causes of urinary potassium wasting
Polyuria 
Potassium depleted subjects can normally reduce the urine potassium concentration to a minimum of 5 to 10 meq/L
Renal tubular acidosis 
Hypomagnesemia 
via an uncertain mechanism
Amphotericin B 
Salt-wasting nephropathies 
Liddle's syndrome 
Gittleman

19. Evaluation of the patient with hypokalemia
REGULATION OF POTASSIUM EXCRETION 
The urinary response to potassium depletion is twofold

20. ASSESSMENT OF URINARY POTASSIUM EXCRETION
A 24-hour urine collection is the most accurate method
Potassium excretion Higher 25 to 30 meq per day suggest at least a contribution from urinary potassium wasting.
Random measurement
Urine potassium concentration is higher than 15 meq/L suggest at least a component of potassium wasting.

21. Pitfall The effect of the diuretic has worn off Polyuria
Urine volume is only 500 mL due to a low rate of water intake
Urinary sodium excretion should be above 30 to 40 meq per day to avoid this problem.

22. Severe hypokalemia 24-hour potassium excretion is impractical
on a single urine specimen
Potassium-to-creatinine ratio
Less than 13 meq/g creatinine
Transtubular potassium concentration gradient.
Do not recommend using the TTKG

23. ASSESSMENT OF ACID-BASE STATUS
Metabolic acidosis with a low rate of urinary potassium excretion is suggestive of lower gastrointestinal losses
Metabolic acidosis with urinary potassium wasting is most often due to diabetic ketoacidosis or to type 1 (distal) or type 2 (proximal) renal tubular acidosis.

24. Metabolic alkalosis + low rate of urinary potassium excretion =surreptitious vomiting
Metabolic alkalosis + urinary potassium wasting and a normal blood pressure :
Diuretic use
Vomiting
Gitelman
Bartter syndrome

25. Metabolic alkalosis + urinary potassium wasting + hypertension:
Surreptitious diuretic therapy in a patient with underlying hypertension, Renovascular disease, or primary mineralocorticoid excess

26. بیمار خانم 51 ساله که به دلیل دلدرد اتساع شکم و کاهش وزن مراجعه نموده بیمار سابقه استفراغ مکرر را داشته و از دو هفته قبل عدم دفع گاز و مدفوع داشته و در معاینه 5-6 کیلوگرم کاهش وزن داشته
دستورات اولیه شامل سرم قندی نمکی + 10 سی سی کلرید پتاسیم هر 8 ساعت

27. نقایص شرح حال ؟

28. وازمایشات درخواستی CBC /Na/K/BS/LFT /PT/PTT
6واحد خون رزرو
سفازولین رانیتیدین شیاف دیکلوفناک
جواب آزمایشات روز اول
Na=140 /K=2.9 / Cr = 0.6 / BUN =13 / WBC = 6400 / Hb= 9.1 // PLT = 245

29. کدام درمان را بهتر میدانید؟
انجام لاپاراتومی و اصلاح انسداد
اصلاح هیپوکالمی

30. انجام لاپاراتومی و اصلاح انسداد
بیمار لاپاراتومی شده ولی بهبودی نداشته شکم متسع بوده
دستورات شامل انتی بیوتیک و سرم رینگر و رانیتیدین وریدی بوده

31. اصلاح هیپوکالمی Kcl orally? 20 mEq/L K in NS ? 20 mEq/L k in DW ?
20 mEq/L in manitol ?
6 mEq/L direct IV ?

32. Kcl orally?
meq 3-4 timse per day

33. چه مواقعی 20 mEq/L K in NS ? 20 mEq/L k in DW ? 20 mEq/L in manitol ?
6 mEq/L direct IV ?

34. جواب آزمایشات بعد از عمل WBC=1800 / Hb = 9
جواب آزمایشات بعد از عمل WBC=1800 / Hb = 9.7 / PLT = / Na = 157 / K = 2.9
بعد از عمل حال عمومی بیمار خوب بود ه اختلال همودینامیک نداشته شکم هنوز متسع بوده و تهوع و استفراغ ندارد
بیمار ترخیص شده و چند ساعت بعد فوت شده

35. ارزوی سلامتی برا ی همگان