Question

Acid-Base Case Studies

(15 questions)

Case 1.

23 y/o patient is two days post-op following a small bowel resection. The patient’s nasogastric (NG) tube is connected to low intermittent wall suction with copious amounts of green liquid drainage.   Urine output has decreased to 0.3mL/kg/hr despite receiving IV fluids. Labs are as follows:

pH 7.52
PO2 90	Na 144
PCO2 48	K 3.2
HCO3 39	Cl 94

What does the pH indicate?

Is the primary process metabolic or respiratory? Why?

Calculate the anion gap? Is the gap normal or abnormal?

Is compensation occurring? Full or partial?

What is the likely cause of this acid -base disturbance?

Case 2.

56 y/o patient with asthma is admitted to the hospital with labored breathing after several days of diarrhea. The patient is treated with bronchodilators and oxygen but his breathing continues to worsen. Labs are as follows:

pH 6.94
PO2 90	Na 137
PCO2 60	K 2.1
HCO3 15	Cl 111

What does the pH indicate?

Is the primary process metabolic or respiratory? Why?

Calculate the anion gap? Is the gap normal or abnormal?

Is compensation occurring?

What is the likely cause of this acid- base disturbance?

Case 3.

67 y/o patient with a history of Cohn’s disease was admitted to the hospital with a perforated bowel and peritonitis. Patient is now status post (s/p) colectomy with a fever of 103 F. Patient is transferred to the ICU with the following labs:

pH 7.12
PO2 85	Na 140
PCO2 19	K 4.8
HCO3 5	Cl 105

What does the pH indicate?

Is the primary process metabolic or respiratory? Why?

Calculate the anion gap? Is the gap normal or abnormal?

Is compensation occurring?

What is the likely cause of this acid -base disturbance?

Answer 1

Case 1,

PH indicate alkalosis.. blood PH above 7.45 is considered to be in alkalosis..

Normal ranges acid- base balance

Po2 (80-90)

Pco2 (36 -44)

Hco3 (21-28)

Na (136-145)

K (3.5 -5.0)

Cl (98-106)

Metabolic Alkalosis

When there is large loss of gastric content that time PH will increase and HCO3 level also will be high or an excessive loss of acids has occurred..

Anion gap is the difference between sodium and potassium and the primary measured anion ( chloride and bicarbonate) in serum..This test will be performed in patients with acute illness.. normal range of anion gap with potassium 12-16 mEq/ l.. without potassium 8- 12 mEq/ l

Anion gap = Na + K _(CL +Hco3)

144 + 3.2 _(94 +39)

147.2 _133

AG = 14.2

Patient having normal AG

Compensation for this case by replacing IV fluid administration.. partial compensation occuring for this patient..

Acid base disturbance cause for this condition is Acid loss and HCo3 retention,low potassium level,loss of gastric acid, dehydration Because the patient having low urine output..

Case 2:

This case PH indicate alkalosis

Primary process is respiratory alkalosis..because PH is high because an increase in respiratory rate or volume.

Anion gap = 137 +2.1 _( 111 +15)

139.1_126

Anion gap= 13.1..it is normal with potassium range..

Compensation happening with oxygen administration and bronchodilator..cause for this acid base disturbance is dehydration and breathing difficulty ( hypo ventilation)..