Case study - Impaired gas exchange: Nursing

Nurse Emily works in an emergency department and is caring for Carolyn, a 77-year-old female with a history of congestive heart failure, or CHF, who came to the emergency department after shortness of breath woke her up during the night. After settling Carolyn in her room, Nurse Emily goes through the steps of the Clinical Judgment Measurement Model to make clinical decisions about Carolyn’s care by recognizing and analyzing cues, prioritizing hypotheses, generating solutions, taking action, and evaluating outcomes.

Nurse Emily begins by recognizing important cues. During report, Nurse Emily learns Carolyn has gained 7 pounds in the last week and has been using extra pillows to prop her up at night since she's short of breath when lying flat. Then, Nurse Emily assesses Carolyn’s vital signs, which are blood pressure 110/70 mmHg, heart rate 100 beats per minute, temperature 98.8 F or 37.1 C, respirations 24 breaths per minute and pain score of 0 out of 10. Pulse oximetry is 86 percent on room air. Nurse Emily notes Carolyn has bilateral lower extremity edema and upon auscultation she hears crackles bilaterally. She also notices Carolyn’s increased work in breathing through cues like nasal flaring and intercostal retractions. 

Then, Nurse Emily analyzes these cues. She reviews Carolyn’s diagnostic test results and sees her CBC, basic metabolic panel, or BMP, and ECG are within normal limits; however, her arterial blood gas, or ABG, reveals a decreased partial pressure of oxygen, or PaO2. Nurse Emily remembers that since Carolyn has CHF, her heart is not pumping effectively, impairing oxygenation, which is the ability of the lungs to exchange oxygen and carbon dioxide. This also impairs perfusion, which is the ability of oxygen-rich blood to travel throughout the body. Nurse Emily also realizes Carolyn’s CHF is causing blood to pool in Carolyn’s pulmonary and systemic circulation, leading to her symptoms.