Acid-Base Disorders

Terms in this set (107)

HPI: BF is a 42yo man with type I DM, HTN, and stage 5 CKD (chronic kidney disease) comes to the clinic complaining of "not feeling too good". He receives HD (hemodialysis) TIW (three times a week). Two days earlier, he developed fever, chills, general malaise, and SOB. This morning, he developed N/V. He admits to missing his HD session 2 days ago.
PMH:
1. IDDM since age 18.
2. HTN x12yrs.
3. CKD 5, on HD x5yrs (pt has no residual renal function).
4. L arm AV graft thrombus formation with thrombectomy last month; multiple episodes of AV graft thrombus formation.
5. AV graft infected with MRSA 2 months ago.
6. Hyperlipidemia.
7. Secondary hyperparathyroidism.
FH: Father with CAD; no family history of DM, HTN, CA.
SH: retired from glass factory; on disability; past history of smoking (quit 3yrs ago); (-) EtOH for the past 7yrs.
Allergies: NKDA.
Meds:
Warfarin 2.5mg po qd
Ranitidine 150mg po qd
Calcium acetate 667mg, 2tabs po tid
Nephrocaps 1tab po qd
Sodium ferric gluconate 62.5mg IV once weekly w/ HD
Clonidine patch, TTS-2, 1patch once weekly
Procardia XL 60mg po qd
Lipitor 10mg po qd
Lispro 6units SC before meals
Glargine 24units SC at HS
Epogen 6000IU IV TIW w/ HD
Calcijex 2mcg IV TIW w/ HD
Ensure 1bottle (240ml) po tid

PE (physical exam): Patient appears to be in mild to moderate distress.
VS: BP 172/86, P 122, RR 18, T 39oC
Dry body wt 72kg, ht 5'11"
Erythematous L arm AV graft site with marked tenderness, warm to the touch. Extremeties: trace B (bilateral) pedal edema.
Labs:
Na 135 Hgb 12.3 Ca 10.2
K 5.8 Hct 35.5% Mg 2.2
Cl 97 Plt 205x103 Phos 7.6
CO2 22 WBC 13.4x103 AST 35
BUN 71 ALT 29
Scr 8.8 T. bili 0.9
Glu 127 Alk Phos 87
Alb 2.8
Intact PTH 140 (last month 175) (normal 10-55)

EKG: sinus tachycardia.
Blood culture from AV graft (+) for coagulase-positive cocci.
Plan: Will dialyze now to correct some of the electrolyte abnormalities. Will start Vancomycin for probable MRSA-infected dialysis graft.

1. Evaluate patient's lab values and indicate which are elevated and which are low.
a) Elevated:
b) Low:

2. List three main electrolyte abnormalities:
a)
b)
c)

3. Could any of the medications or nutritional supplements the patient is receiving be contributing to his hyperkalemia?

4. What is the pathophysiology of the patient's hyperkalemia?

5. List signs and symptoms of severe hyperkalemia:

6. List pharmacological agents used for the treatment of severe/symptomatic hyperkalemia (K>7mEq/L) and explain their mechanism of action?

7. What nondrug therapies are available for treating hyperkalemia in this patient?

8. Calculate corrected calcium level for this patient.

9. Could any of the patient's medications be contributing to his hyperphosphatemia and hypercalcemia?

10. What is the pathophysiology of the patient's hyperphosphatemia and hypercalcemia?

11. What non-drug therapies might be useful for treating this patient's hyperphosphatemia and hypercalcemia?

12. What pharmacotherapeutic alternatives are available for treatment of hyperphosphatemia in this patient?

13. What pharmacologic products are available to treat hypercalcemia in this patient?
HPI: J.L., a 25yo, 60-kg woman with an 8-year history of type 1 diabetes, is moderately well controlled on 24 units insulin glargine plus premeal doses of insulin lispro. Her family brings her to the emergency department, where she complains of abdominal tenderness, nausea, and vomiting. According to her family, J.L. was well until 2 days ago when she awoke with nausea, vomiting, diarrhea, and chills. Because she was unable to eat, she omitted her usual morning dose of insulin. Her GI symptoms progressed, and she was brought to the emergency department when she became lethargic.

PE: Reveals an ill-appearing woman who is lethargic but responsive. Her T is 37°C. Skin turgor is poor, mucous membranes are dry, and her eyeballs are shrunken and soft. J.L.'s lungs are clear, but respirations are deep and her breath has a fruity odor. Cardiac examination is within normal limits.

Labs on admission: BG (blood glucose) 750 mg/dL, Na 127 mEq/L, K 5.4 mEq/L, Cl 102 mEq/L, CO2 6 mEq/L, Scr 2.0 mg/dL, Hgb 14.7 g/dL, Hct 49%, WBC 15,000/mm3 with 3% bands/70% polymorphonuclear neutrophils/ 27% lymphocytes; serum ketones positive.

The urinalysis showed: 2% glucose, moderate ketones, pH 5.5, specific gravity of 1.029; there were no WBCs, RBCs, bacteria, or casts.

ABG: pH 7.05, PCO2 20 mmHg, PO2, 120 mmHg, HCO3 6mEq/L.

Patient diagnosed with DKA (diabetic ketoacidosis) and admitted for fluid, electrolytes, and insulin infusions.

1. Interpret ABG result and indicate what acid-base disorder does JL exhibit?

2. Calculate anion gap on admission for this patient. Explain the meaning of the numerical value.

3. What is the cause of patient's acid-base disorder?

4. What type of hyponatremia does this patient have? Explain the reason for it?

5. Explain the reason for hyperkalemia in this patient?