Critical care case study - Acute respiratory distress syndrome: Nursing

Nurse Tamara works in the ICU and is caring for Matthew, a 67-year-old who was diagnosed with acute respiratory distress syndrome, or ARDS. Nurse Tamara goes through the steps of the Clinical Judgment Measurement Model to make clinical decisions about Matthew’s care by recognizing and analyzing cues, prioritizing hypotheses, generating solutions, taking action, and evaluating outcomes.

First, Nurse Tamara recognizes important cues, including Matthew’s vital signs which are temperature 101.2 F or 38.4 C, heart rate 110 beats per minute, respirations 24 breaths per minute, blood pressure 90/45 mmHg, and oxygen saturation 89 percent. Matthew is intubated and mechanically ventilated with an FiO2 of 50% and PEEP of 10 cm H2O; and he has a sedative and neuromuscular blocker infusing in a central line. Upon assessment, Nurse Tamara notes bilateral fine crackles in his lung bases.

Next, Nurse Tamara analyzes these cues. She reviews the electronic health record, or EHR, and notes that Matthew was admitted for pneumonia and recently developed ARDS, after which he was intubated. His most recent chest X-ray shows diffuse alveolar infiltrates, bilaterally. She also reviews Matthew’s labs, including his most recent arterial blood gas, or ABG, which indicates respiratory acidosis; low partial pressure of oxygen, or PaO2; and an elevated partial pressure of carbon dioxide, or PaCO2.

Nurse Tamara knows that ARDS is a severe condition characterized by lung inflammation and pulmonary edema that’s triggered by an underlying lung injury, like pneumonia. Inflammatory mediators are released at the site of injury, damaging the alveolar-capillary membrane where gas exchange occurs. This results in increased capillary permeability and edema, as protein-rich fluid leaks into the alveoli, impairing their ability to participate in gas exchange. Also, the damaged type II pneumocytes start producing less surfactant, so there’s more surface tension within the alveoli, which makes them more likely to collapse. Less surfactant also makes the lungs less compliant, meaning they don’t stretch and expand easily, so ventilation is more difficult. Together, these events lead to hypoxemia, or low blood oxygen levels.

Adding to this is an accumulation of dead cells and fluid that starts to pile up in the alveolar space, forming a waxy hyaline, or glassy-appearing material, making gas exchange even more difficult, even when receiving a high concentration of oxygen. And because ventilation is compromised but perfusion of deoxygenated blood continues to flow to the alveoli, there’s a ventilation-perfusion, or V/Q mismatch. Finally, fibroblasts start to multiply and begin laying down large amounts of collagen, causing lung tissue to become fibrotic and stiff, further impairing ventilation. Ultimately, ARDS can progress to multiple organ failure and death.

Nurse Tamara knows Matthew needs prompt respiratory management to prevent ARDS from progressing.

Now, using the information she’s gathered, Nurse Tamara chooses a priority hypothesis of impaired gas exchange. Then, she generates solutions to address Matthew's impaired gas exchange including pharmacologic and non-pharmacologic interventions; and she establishes the expected outcome that after intervening, Matthew's oxygen saturation will be above 92% within 2 hours.

Then Nurse Tamara takes action to implement these solutions. First, she reviews orders that include a scheduled IV antibiotic and an antipyretic for fever. Additional orders include respiratory therapy to titrate ventilator settings to maintain oxygen saturation above 92%, prone positioning for 12 hours daily, and repeat ABGs today.