afib - Nursing Case Study

Pathophysiology

• Primary mechanism: Atrial fibrillation (AFib) develops due to disorganized electrical signals in the heart's atria, leading to rapid and irregular contractions. This chaotic activity prevents the atria from effectively emptying into the ventricles, compromising cardiac output.

• Secondary mechanism: Over time, AFib can cause structural changes in the heart tissue (remodeling). The constant rapid and irregular contractions lead to atrial enlargement and fibrosis, which further perpetuates AFib, creating a vicious cycle.

• Key complication: The irregular contractions in the atria can lead to blood pooling and clot formation (thromboembolism), which poses a risk for stroke if a clot dislodges and travels to the brain.

Patient Profile

Demographics:

67 years old, male, retired engineer.

History:

• Key past medical history: Diagnosed with atrial fibrillation 3 years ago, hypertension, type 2 diabetes.

• Current medications: Metoprolol, Warfarin, Metformin.

• Allergies: No known drug allergies.

Current Presentation:

• Chief complaint: Increasing fatigue, shortness of breath, and palpitations.

• Key symptoms: Palpitations, general fatigue, shortness of breath, occasional dizziness, mild swelling in the legs.

• Vital signs: Blood pressure 150/90 mmHg, heart rate irregular at 110 bpm, respiratory rate 20 breaths per minute, oxygen saturation 94%.

Section 1

Change in patient status:

The patient's fatigue and shortness of breath seem to be worsening. His oxygen saturation has dropped from 94% to 90% over the course of the day, and his heart rate continues to be irregular, now averaging 120 bpm. The patient reports increased palpitations and a feeling of lightheadedness. On assessment, the nurse notes that the patient's lower extremities are significantly more swollen than on initial admission. Moreover, the patient complains of chest discomfort described as a "pressure" sensation.

New diagnostic results:

The health care team has ordered a series of lab tests and imaging studies to understand the patient's condition better. His blood tests reveal an elevated B-type natriuretic peptide (BNP) level of 900 pg/mL (normal range: 0-100 pg/mL), indicating heart failure. His Troponin I level is slightly elevated at 0.05 ng/mL (normal range: 0-0.04 ng/mL), suggesting some myocardial injury. A repeat ECG confirms persistent AFib with a rapid ventricular response. A transthoracic echocardiogram reveals left atrial enlargement and reduced ejection fraction (EF) of 45% (normal range: 55-70%), suggesting systolic dysfunction. These findings, along with the patient's worsening symptoms, suggest the development of AFib-related heart failure.

Section 2

Continuing assessment findings:

The nurse revisits the patient, who now reports increased difficulty in breathing, even at rest, and his oxygen saturation has further dropped to 88% on room air. The nurse also notes that the patient's respiratory rate has increased to 22 breaths per minute, indicating possible respiratory distress. On auscultation, the nurse hears crackles in the lower lung fields, further corroborating the suspicion of fluid overload due to worsening heart failure. The patient's pulse is still irregular, and his blood pressure has dropped to 100/65 mmHg, which might be a result of decreased cardiac output due to the fast and irregular heart rate.

Response to interventions:

To address the patient's declining oxygen saturation and respiratory distress, the nurse immediately places the patient on 2L of supplemental oxygen via nasal cannula, which improves his oxygen saturation to 92%. The healthcare team initiates intravenous diuretics to help reduce the fluid overload signified by the patient's swollen lower extremities and the presence of crackles on auscultation. The healthcare team also adjusts the patient's rate-controlling medications to try to slow down the heart rate and alleviate the lightheadedness. The nurse continues to closely monitor the patient's vital signs and symptoms, ready to escalate care if necessary.

Section 3

New diagnostic results:

The healthcare team obtains an EKG, which continues to show atrial fibrillation with a rapid ventricular response. Lab results reveal a B-type natriuretic peptide (BNP) level of 900 pg/mL, indicating severe heart failure. Additionally, the patient's blood chemistry is notable for an elevated creatinine level at 2.0 mg/dL and a decreased glomerular filtration rate (GFR) of 45 mL/min, suggesting that the patient's kidney function is also compromised. The patient's hemoglobin level is slightly decreased at 11.5 g/dL, but the hematocrit is within normal range.

Change in patient status:

While awaiting further instructions from the healthcare team, the nurse notices that the patient's respiratory rate has increased to 26 breaths per minute, and he appears increasingly uncomfortable and anxious. His oxygen saturation has dropped to 90%, despite receiving supplemental oxygen. The nurse also observes that the patient's lower extremities appear more swollen than before and his blood pressure has further dropped to 90/60 mmHg. He is expressing increasing concern about his condition and asks the nurse if his heart failure is getting worse.

Section 4

Change in Patient Status:

The nurse quickly reevaluates the patient, noting that the patient's skin is clammy and cool to the touch. His heart rate has further increased to 130 beats per minute. The nurse auscultates crackles in the lower lobes of the lungs and notices that the patient's jugular veins are distended. On further examination, the nurse also observes that the patient's urine output has decreased to just 20 mL over the past hour, and the patient reports increasing levels of fatigue and weakness.

New Complications:

This sudden change in the patient's status leads the nurse to suspect that the patient may be experiencing a worsening of his heart failure, possibly with acute decompensated heart failure or cardiogenic shock. The increased heart rate, decreasing blood pressure, increased respiratory rate, and decreased oxygen saturation are concerning findings that suggest a worsening cardiac condition. Additionally, the decreased urine output, elevated creatinine levels, and lowered GFR may indicate that the patient's compromised cardiac function is leading to decreased renal perfusion and acute kidney injury. The nurse quickly alerts the healthcare team about the patient's deteriorating condition and prepares for immediate interventions.

Section 5

New Diagnostic Results:

The healthcare team responds swiftly and conducts an immediate electrocardiogram (EKG), which shows an irregular rhythm with no identifiable P waves - a pattern consistent with the patient's history of atrial fibrillation. A chest x-ray reveals pulmonary congestion, suggesting fluid overload due to worsening heart failure. Lab results show an increase in B-type natriuretic peptide (BNP) to 900 pg/mL (normal range: 0-100 pg/mL) indicating heart failure. Additionally, the patient's creatinine levels have risen to 2.5 mg/dL from a baseline of 1.0 mg/dL, and the GFR has dropped to 30 mL/min, both of which are indicative of acute kidney injury likely due to decreased renal perfusion.

The arterial blood gas (ABG) analysis indicates respiratory alkalosis with a pH of 7.48, PaCO2 of 32 mmHg, and bicarbonate of 24 mEq/L, likely due to the patient's increased respiratory effort. The blood oxygen saturation (SpO2) level has decreased to 90%, suggestive of hypoxemia. These results confirm the nurse's suspicion of a deteriorating cardiac condition and possible cardiogenic shock. The healthcare team must now determine an appropriate intervention plan to manage these complications. By correlatively analyzing these new findings, the nurse would be able to participate effectively in the multidisciplinary discussion to formulate a comprehensive plan of care.