Wilkin's Chapter 8: Interpretation of ABGs

A patient has a measured SaO2 of 82%. What is his approximate PaO2? a. 50 mm Hg b. 60 mm Hg c. 70 mm Hg d. 80 mm Hg

40-50-60/70-80-90 A. 50 mm Hg

A 17 year old man is brought into the ER. Vitals are as follows: pulse 100 beats/minute; RR 4 breaths/minute, BP 100/65 mm Hg. The patient was at a party where he was discovered by his friends to be slumped in a chair and unresponsive. ABG results are as follows: pH 7.24, PaCO2 68 mm HG, HCO3 28 mmol/L, BE +1 mmol/L. The patient's acid-base status is classified as which of the following? a. uncompensated resp. acidosis b. partially compensated resp. acidosis c. compensated resp. alkalosis d. uncompensated met. acidosis

A

A 35 year old, 54-kg woman with CHF enters the ER with shortness of breath. An ABG sample shows the following results: pH 7.51, PaCO2 30 mm Hg, HCO3 23 mmol/L, BE +1 mmol/L. These results indicate which of the following? a. uncompensated resp. alkalosis b. compensated resp. acidosis c. uncompensated met. alkalosis d. uncompensated met. acidosis

A

An acute increase in the PaCO2 of 10 mm Hg to 15 mm Hg causes a corresponding increase in plasma HCO3 of how much? a. 1 mmol/L b. 2 mmol/L c. 3 mmol/L d. 4 mmol/L

A

Continuous noninvasive assessment of patient oxygenation can be provided by which of the following methods? 1. transcutaneous PO2 2. capnography 3. pulse oximetry 4. indwelling arterial line a. 1 and 3 b. 1 and 2 c. 3 and 4 d. 1, 3, and 4

A

Given the following ABG results, interpret the acid-base status: pH 7.14, PaCO2 55 mm Hg, HCO3 18 mmol/L. a. combined resp. and met. acidosis b. partially compensated resp. acidosis c. mixed resp. acidosis and met. acidosis d. uncompensated met. acidosis

A

What is the common reference range for CaO2? a. 16-20 mL/dL b. 12-16 mL/dL c. 8-12 mL/dL d. 4-8 mL/dL

A

Which of the following infection control precautions would you apply when obtaining an arterial blood gas sample? a. standard precautions plus face shield b. contact precautions plus gown c. droplet precautions plus surgical mask d. airborne precautions plus N95 respirator

A

Which of the following is the preferred site for arterial puncture? a. radial b. femoral c. dorsalis pedis d. brachial

A

Which of the following is true regarding respiratory alkalosis? a. PaCO2 is less than 35 mm Hg b. an increase in HCO3 compensates for resp. alkalosis c. it is called completely compensated if the pH is 7.52 d. it is called partially compensated if the pH is in the normal range

A

Which of the following parameters represents the respiratory component of acid-base status? a. PaCO2 b. HCO3 c. PaO2 d. BE

A

A patient breathing 40% O2 has a markedly higher than normal P(A-a)O2, which does not improve when the O2 concentration is increased to 50%. What is the most likely cause of her hypoxemia? a. V/Q imbalance b. Pulmonary shunting c. hypoventilation d. diffusion defect

B

An 80 year old patient has a PaO2 of 71 mm Hg. How would you describe this finding? a. normal for his age b. mild hypoxemia c. moderate hypoxemia d. severe hypoxemia

B

Given the following ABG results, interpret the acid-base status: pH 7.42, PaCO2 56 mm Hg, HCO3 35 mmol/L. a. partially compensated metabolic alkalosis b. mixed metabolic alkalosis and respiratory acidosis c. combined resp and met alkalosis d. fully compensated resp acidosis

B

In performing an Allen test of a patient's left wrist before drawing an arterial sample, you note that her hand remains blanched for more than 25 seconds after releasing pressure on the ulnar artery. Which of the following actions would you take this this time? a. insert a catheter into the brachial artery b. repeat the test on the opposite wrist c. report that the sample cannot be obtained d. proceed with sampling through left radial artery

B

The best way to minimize the impact of cell metabolism on analysis of an ABG sample is to: a. use extra heparin in the syringe b. analyze the sample within 30 minutes c. immediately place the sample on ice d. fully expel all air bubbles

B

The procedure whereby a blood-measuring instrument is exposed to samples at two or more known levels to ensure accuracy is termed: a. proficiency testing b. analyzer calibration c. pre-analytic validation d. preventive maintenance

B

What is the common reference range for arterial pH? a. 7.25-7.35 b. 7.35-7.45 c. 7.45-7.55 d. 7.55-7.65

B

Which of the following causes metabolic acidosis? a. hyperventilation b. renal disease c. hypokalemia d. vomiting

B

Which of the following could you use to assess the adequacy of ventilation in an intubated child receiving mechanical ventilation? 1. transcutaneous PCO2 2. capnography 3. pulse oximetry 4. arterial blood gas a. 1 and 2 only b. 1, 2, 4 c. 4 only d. 1, 2, 3

B

Which of the following is the best indicator of metabolic acid-base status? a. plasma HCO3 b. BE c. standard HCO3 d. T40 HCO3

B

Which of the following is true regarding standard pulse oximeters? a. They measure the fractional saturation of Hb (O2 Hb to total Hb) b. In patients with good perfusion, their accuracy is in the 2% to 4% range c. Their accuracy increases when the Hb saturation drops below 65%-70% d. In the presence of dyshemoglobins, they tend to underestimate the true SaO2

B

Which of the following ratios of HCO3/PaCO2 would result in a pH of 7.40? a. 24:1 b. 10:0:5 c. 6:0.82 d. 15:1

B

A mixed metabolic acidosis and respiratory alkalosis is likely when the pH and HCO3 are low and the PaCO2 is: a. higher than the predicted b. within its reference range c. lower than the predicted d. 20 times the concentration

C

A patient has the following ABG results: pH 7.33, PaCO2 35 mm Hg, HCO3 18 mmol/L, BE -7mmol/L. Bases on these findings, the patient has which of the following? a. compensated metabolic acidosis b. uncompensated resp. acidosis c. uncompensated met. acidosis d. compensated resp. acidosis

C

Before an arterial blood gas sample is obtained, the patient's clotting parameters should be evaluated because: a. they may affect the accuracy of the sample PaO2 b. if reduced, they may hinder filling of the syringe c. bleeding time may be prolonged if they are abnormal d. they may impact the accuracy of the sample pH

C

Given the following ABG results, interpret the acid-base status: pH 7.62, PaCO2 30 mm Hg, HCO3 30 mmol/L. a. partially compensated met. alkalosis b. mixed resp. alkalosis and met. acidosis c. combined resp. and met. alkalosis d. uncompensated met. alkalosis

C

To evaluate a patient's acid-base status, you would recommend which of the following? a. transcutaneous PCO2 b. pulse oximetry c. arterial blood gas d. CO-oximetry

C

Which of the arterial blood gas acid-base reports represents an error? a. pH= 7.30, PaCO2= 60 mm Hg HCO3= 29 mmol/L b. pH= 7.40, PaCO2= 25mm Hg HCO3= 15 mmol/L c. pH= 7.50, PaCO2= 50 mm Hg HCO3= 20 mmol/L d. pH= 7.60, PaCO2= 35 mm Hg HCO3= 33 mmol/L

C

A 5 year old patient is admitted to the ER with suspected smoke inhalation. To assess the oxygenation status, you would recommend: a. Standard pulse oximetry b. Arterial sample plus arterial blood gas analysis c. Transcutaneous PO2 d. Arterial sample + CO oximetry

D

A patient receiving mechanical ventilation requires frequent assessment of oxygenation, ventilation, and acid-base balance. Which of the following would you recommend? a. PtcO2/PtcCO2 monitoring b. continuous pulse oximetry c. continuous capnography d. arterial blood gas sampling through and A-line

D

Given the following ABG results, interpret the acid-base status: pH 7.45, PaCO2 25 mm Hg, HCO3 17 mmol/L, BE -6 mmol/L. a. compensated met. acidosis b. uncompensated resp. alkalosis c. uncompensated resp. acidosis d. compensated resp. alkalosis

D

The blood gas results from a patient breathing a confirmed O2 concentration pf 30% indicates a PaO2 of 250 mm Hg. Based on this data, it can be concluded that: a. patient has a larger pulmonary shunt b. PaO2 is in the expected range for this % O2 c. patient must be at high altitude d. PaO2 is in error and should be re-measured

D

To measure actual blood O2 saturation, you would recommend: a. transcutaneous PO2 b. pulse oximetry c. arterial blood gas d. CO-oximetry

D

What is the commons reference range for PaO2 breathing air at sea level? a. 50-60 mm Hg b. 60-70 mm Hg c. 70-80 mm Hg d. 80-100 mm Hg

D

Which of the following represents a normal P(A-a)O2 for a 50 year old woman breathing room air? a. 105 mm Hg b. 75 mm Hg c. 45 mm Hg d. 15 mm Hg

D patient's age multiplied by 0.3