arterial blood gases tutorial question

8/14/2019 Arterial Blood Gases Tutorial Question

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ABG TUTORIALSEMIRA ABDI

M. Clin.Pharm (UKM), Bpharm (AAU)


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1. The primary parameter for determining whether a

patient has acidemia or alkalemia include

A. Arterial PH

B. Venous bicarbonate concentrationC. Arterial carbondioxide concentration

D. A & B

E. C& D


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Arterial PH


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2. The primary parameter for determining whether

a patient has respiratory acidosis or alkalosis

include

A. Plasma haemoglobin.

B. Percentage of oxygen saturation.

C. Arterial carbondioxide concentration.

D. A & B

E. A & C


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C. Arterial carbondioxide concentration.


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3. In compensating for respiratory alkalosis, the

body excretes more:

A. ammonium ions.

B. bicarbonate ions.C. dihydrogen phosphate ions.

D. carbonic acid.

E. hydrogen ions.


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B. bicarbonate ions.


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4. Given the following arterial blood gas values:

PH :7.56

PCO2 :31 mmHg

HCO3 : 27 mEq/L

PaO2: 56 mmHg

What is (are) the most likely acid base state(s) in the patient?

A. Acute respiratory alkalosis.

B. Chronic respiratory alkalosis.

C. Respiratory alkalosis and metabolic alkalosis.

D. Respiratory acidosis and metabolic acidosis.

E. Respiratory alkalosis and metabolic acidosis.


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c. Respiratory alkalosis and metabolic alkalosis.


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5. A 37-year-old man presents to hospital with

shallow and slow breathing due to heroin

overdose. His arterial blood gas results were as

follows.

Arterial blood gases (ABG):

pH: 7.30

PaCO2: 55 mm/Hg

HCO3-: 27 mEq/L

What kind of acid base disorder is he having?

Is there adequate compensation?


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Acute Respiratory Acidosis

use winters formula to assess whether there is

adequate compensation or not?

PCO2= 1.5 (HCO3) 8 2

= 1.5 (27) + 8 2

= 48.5 2= (46.5- 50.5)

There is no adequate compensation since the actual

measure CO2 is 55.


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6. A 77-year-old man presents with anxiety of

psychosomatic origin. He has a very rapid

breathing and slurred speech. His ABG results

are as follows.


pH: 7.57

PaCO2: 23 mmHg

HCO3-: 21 mEq/L

what kind of acid base problem is this patient having?


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Acute Respiratory Alkalosis


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7. A 70 year old man with history of CHF presents

with increased shortness of breath and leg

swelling.


pH : 7.24

PCO2 : 60 mmHg

PO2:52

HCO3: 27

What is the acid base disorder?


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RESPIRATORYACIDOSISWITHINADEQUATE

COMPENSATION(METABOLICALKALOSIS)

The pH is low, (less than 7.35) therefore by

definition, patient is acidemic.

PCO2 and HCO3- are abnormal in the same

direction, therefore less likely a mixed acid base

disorder but not yet ruled out.

PCO2 is high and represents acidosis and is

consistent with the pH(Respiratory Acidosis).

The high normal HCO3- must be the compensatory

response.


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8. A 23-year-old woman with gastroenteritis

experiences nausea and vomiting. Arterial blood

gas analysis is done 1 hour after the onset of

symptoms. Which of the following sets of blood

gases is most likely.

A. pH 7.30; PCO2 50; HCO3 - 24

B. pH 7.28; PCO2 40; HCO3 - 18

C. pH 7.56; PCO2 40; HCO3 - 35

D. pH 7.51; PCO2 45; HCO3 - 35


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Choice D is the best answer.

Vomiting causes loss of stomach acid leading to

metabolic alkalosis. The rise in pH will inhibit the

peripheral chemoreceptor for pH located in the

carotid bodies leading to hypoventilation (increased

PCO2), which is compensatory.


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9. Point x indicates the acid base status of a healthy

person at sea level. Point y indicates Data from a

patients ABG analysis. Urine PH is 4.5. what is the

most likely cause of the condition indicated by pointy?

A. Adaptation to high altitude

B. COPD

C. Diabetic ketoacidosisD. Infusion of sodium lactate

E. Severe prolonged vomiting


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Answer is c. pH was sl igh t ly below 7.4

(compensat ion is usual ly not complete and

does not overshoot) AND the stem stated that

ur ine pH was acidic. With respiratory alkalosis,

the kidneys are excret ing bicarbonate and pH is

no rmal ly alkal ine.


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THANK YOU

arterial blood gases tutorial question

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