Help please! case study about Excretory System

[kochibaza]

A 50 years old woman presents with cough, dyspnea and generalized edema. She
also has small urine output, nausea, vomiting, fatigue and anorexia. She was diagnosed as diabetic
mellitus for 10 years ago and non-regular treatment.
Physical examination
Vital signs: BT 37 °C (37-37.5), PR 96 /min (80-100), RR 36 /min (25-30) BP 150/90 mmHg
HEENT : pale conjunctivae, neck vein engorged
Heart : regular rhythm, normal heart sound.
Lungs : fine crepitation at both lungs.
Abdomen : ascites was positive.
Extremities : pitting edema of both legs
Investigation
Blood examination
1. CBC: Hct 20%, Hb 7%
2. BUN 100 mg/dl, Cr 10 mg/dl
3. Serum electrolytes: Na 130 mEq/L, K 6.5 mEq/L, Cl 102 mEq/L, HCO3
- 4.5 mEq/L
4. Serum albumin 3.0 gm/dl
5. Random plasma sugar 250 mg/dl
6. ABG (Arterial Blood Gas): pH 7.30, PaCO2 28 mmHg, PaO2 90 mmHg
Physician made the diagnosis as renal failure and admitted her. She was treated with
intravenous 7.5% sodium bicarbonate, 10% calcium gluconate and subcutaneous insulin

First, i have no clue what is the normal range from blood examination and to answers these questions one should know physiology and pathology of overall body, i have only learned a few so it's impossible to me diagnose all he thing they gave me even if i guess the cause of symptom i couldn't ensure that my opinion is correct.

questions
1. Why this patient has decreased urine output? please explain the mechanism.
2. How did edema occur in this case?
3. What is/are the causes of nausea, vomiting, anorexia and fatigue?
4. How did crepitation and ascites occur in this case?
5. Is there any acid-base disorder in this patient? How?
6. Why did the physician give him 7.5% sodium bicarbonate, 10% calcium gluconate and insulin?

[daniel.kurz]

Looks like kidney disease or uncontrolled diabetes.