Review Question - QID 104282

Action	Numeric Key	Letter Key	Function Key
Choose 1	1
Choose 2	2
Choose 3	3
Choose 4	4
Choose 5	5
Submit Response			Enter
Previous Question			Left Arrow
Next Question		N	Right Arrow
Open/Close Bookmode		C
Open Image			Spacebar

Acid-Base Differential Diagnosis Introduction Simple acid-base disorders QID: 104282 (M1.RL.14.8)

QID 104282 (Type "104282" in App Search)

A 66-year-old man is brought to the emergency department by his daughter because of 3 days of fever, chills, cough, and shortness of breath. The cough is productive of yellow sputum. His symptoms have not improved with rest and guaifenesin. His past medical history is significant for hypertension, for which he takes hydrochlorothiazide. He has a 30-pack-year history of smoking. His temperature is 38.9 C (102.0 F), blood pressure 88/56 mm Hg, and heart rate 105/min. Following resuscitation with normal saline, his blood pressure improves to 110/70 mm Hg. His arterial blood gas is as follows:

Blood pH 7.52, PaO2 74 mm Hg, PaCO2 28 mm Hg, and HCO3- 21 mEq/L.

Which of the following acid-base disturbances best characterizes this patient's condition?

Type & Select Correct Answer

Type in at least one full word to see suggestions list

Normal acid-base status

3/275

Metabolic acidosis

6/275

Metabolic alkalosis

11%

31/275

Respiratory acidosis

6/275

Respiratory alkalosis

82%

225/275

Select Answer to see Preferred Response

Review TC In New Tab

This patient's elevated blood pH and decrease in PaCO2 is consistent with acute respiratory alkalosis.

Respiratory acid-base disorders are caused by primary changes in PaCO2, whereas metabolic acid-base disorders are due to primary changes in the concentration of HCO3-. A primary rise in PaCO2 or a fall in plasma HCO3- reduces the pH (acidemia), whereas the opposite increase the pH (alkalemia). Patients suffering from pneumonia can have tachypnea due to hypoxia. Increased minute ventilation reduces arterial CO2, an acid, resulting in alkalosis. A slight decrease in bicarbonate level may be seen due to early renal compensation.

Incorrect Answers:
Answer 1: Normal pH range is 7.35-7.45. This patient's pH is outside this range, which indicates an acid-base disturbance.
Answer 2: A decreased pH and an decrease in HCO3- would be consistent with metabolic acidosis.
Answer 3: An elevated pH and an increase in HCO3- would be consistent with metabolic alkalosis.
Answer 4: Respiratory acidosis results from decreased alveolar ventilation, which causes increased arterial CO2 levels.

Rating

Please Rate Question Quality

3.9

(7)