Question

The patient is a 60-year-old Caucasian female presenting to the emergency department with acute onset shortness of breath. Symptoms began approximately 2 days before and had progressively worsened with no associated, aggravating, or relieving factors noted. She had similar symptoms approximately 1 year ago requiring hospitalization. She uses BiPAP ventilatory support at night when sleeping.

She denies fever, chills, cough, wheezing, and sputum production but does get short of breath easily.

There are no known ill contacts at home. Her family history includes significant heart disease and prostate malignancy in her father. Social history is positive for smoking tobacco use at 30 pack years. She quit smoking 2 years ago due to increasing shortness of breath. She denies all alcohol and illegal drug use. There are no known foods, drugs, or environmental allergies.

Physical Exam

Initial physical exam reveals temperature 97.3 F, heart rate 74 bpm, respiratory rate 24, BP 104/54, BMI 40.2, and O2 saturation 90% on room air.

Pulmonary/Chest: No respiratory status distress at this time, tachypnea present, (+) wheezing noted, bilateral rhonchi, decreased air movement bilaterally. Patient barely able to finish a full sentence due to shortness of breath.

ABG: Initial arterial blood gas with pH 7.491, PCO2 27.6, PO2 53.6, HCO3 20.6, and oxygen saturation 90% on room air.

(1) What is your interpretation of the ABG results?

(2) Based on the findings, what is the clinical diagnosis?

(3) What medication would you anticipate the health care provider ordering?

(4) What is the difference between Bipap and CPAP?

Answer 1

Arterial Blood Gas result interpretation is:

pH 7.491 - Typical normal value according to the National Institute of Health is 7.35-7.45. The pH value of 7.491 is slightly high, showing it is alkalotic.

PCO2 27.6 - Typical normal value according to the National Institute of Health is 35-45 mmHg. The (PCO2) partial pressure of carbon dioxide value of 27.6 is low.

PO2 53.6 - Typical normal value according to the National Institute of Health is 75 to 100 mmHg. The (PO2) partial pressure of oxygen value of 53.6 is low.

HCO3 20.6 - Typical normal value according to the National Institute of Health is 22-26 mEq/L. The (HCO3) bicarbonate value of 20.6 is low.

O2 Sat 90% on room air - Typical normal value according to the National Institute of Health is 94-100%. The (O2 Sat) oxygen saturation value of 90% is low.

Here the pH is low and PCO2 is low. This shows the patient has respiratory alkalosis. The HCO3 is also low and this shows the patient has respiratory alkalosis with metabolic compensation.