Sickle cell anemia - Nursing Case Study

Pathophysiology

• Primary mechanism: Sickle cell anemia is caused by a mutation in the HBB gene which codes for beta-globin, a component of hemoglobin. This mutation results in the production of abnormal hemoglobin S (HbS) instead of normal hemoglobin A (HbA). When HbS releases its oxygen to the tissues, it sticks together to form long, rigid rods that deform the red blood cells into a sickle shape.

• Secondary mechanism: The sickle-shaped red blood cells are rigid and sticky, leading to vaso-occlusion. These cells can block small blood vessels, restricting blood flow, which results in ischemia, pain, and eventually necrosis of tissues and organs.

• Key complication: Over time, the continuous sickling and unsickling leads to hemolysis, the premature destruction of red blood cells, resulting in chronic hemolytic anemia. This can trigger severe complications such as acute chest syndrome, stroke, and organ damage due to repeated episodes of ischemia and reperfusion injury.

Patient Profile

Demographics:

45-year-old male, construction worker

History:

• Diagnosed with Sickle cell anemia at age 3

• Currently on Hydroxyurea, Penicillin V, and Folic Acid

• Allergic to Aspirin

Current Presentation:

• Chief complaint of severe abdominal pain and difficulty breathing

• Key symptoms include fatigue, jaundice, delayed growth, episodes of severe pain, and frequent infections

• Vital signs: Blood pressure 170/100 mmHg, Pulse 110 bpm, Respiratory rate 30 breaths per minute, Oxygen saturation 88%, and Temperature 39.1°C (fever)

Section 1

Change in Patient Status:

The patient's condition rapidly deteriorates after admission. His work of breathing escalates, and he becomes increasingly dyspneic with oxygen saturation dropping to 83%. He reports worsening abdominal pain, rating it 9 out of 10 on the pain scale. His blood pressure spikes to 180/110 mmHg, and the pulse quickens to 130 bpm, indicating a possible vaso-occlusive crisis. On auscultation, crackles are heard in the lower lobes of the lungs, suggesting possible acute chest syndrome, a life-threatening complication of sickle cell anemia. The patient's skin and sclera become more jaundiced, and he develops signs of peripheral ischemia, with cool, pale extremities and delayed capillary refill.

New Diagnostic Results:

An immediate chest X-ray reveals infiltrates in the lower lung fields, confirming the suspicion of acute chest syndrome. A complete blood count (CBC) shows a decreased hemoglobin level of 7.1 g/dL, hematocrit of 21.3%, and a raised reticulocyte count of 15%. These values indicate severe anemia and increased red blood cell production, a response to the ongoing hemolysis. Blood chemistry reveals elevated lactate dehydrogenase (LDH) at 800 U/L, suggestive of tissue damage, and indirect bilirubin of 3.2 mg/dL, signaling increased red cell breakdown. The patient's white blood cell count is elevated at 18,000/mm3, indicating possible infection or inflammation. The prothrombin time (PT) and activated partial thromboplastin time (aPTT) are prolonged at 16 seconds and 35 seconds, respectively, indicating a potential coagulopathy. These findings require immediate attention and advanced clinical reasoning to manage the patient's deteriorating condition.

Section 2

Response to Interventions:

Despite aggressive fluid resuscitation and supplemental oxygen, the patient's dyspnea and hypoxia persist, with oxygen saturation lingering around 85%. His blood pressure remains elevated at 175/105 mmHg and pulse at 135 bpm, suggesting uncontrolled severe pain and potential onset of malignant hypertension. The administration of intravenous opioids for pain relief initially lowers the pain score to 6 out of 10, but the relief is short-lived. Within an hour, the patient's pain score climbs back up to 8. The patient's hemoglobin level post-transfusion rises to 8.5 g/dL, a modest improvement that does not correspond to the urgency of the situation. Meanwhile, the patient's jaundice intensifies, and signs of peripheral ischemia worsen, with capillary refill time extending to 4 seconds.

New Complications:

The patient's condition continues to deteriorate, and he develops a high-grade fever of 39.5 degrees Celsius (103.1 degrees Fahrenheit). His mental status begins to fluctuate, with episodes of confusion and agitation, raising concerns for possible sepsis or meningitis. Repeat blood cultures are drawn, and broad-spectrum antibiotics are initiated. A lumbar puncture is also considered to rule out meningitis. The patient's respiratory status worsens, with a respiratory rate of 28 breaths per minute and decreased breath sounds in the right lower lung fields now evident on auscultation. His oxygen saturation drops to a concerning 78% on 4L nasal cannula. An arterial blood gas (ABG) reveals a PaO2 of 55 mmHg, indicating severe hypoxemia. This worsening respiratory failure and potential sepsis or meningitis further complicate the clinical picture, requiring swift, complex decision-making and interventions.

Section 3

New Diagnostic Results:

Laboratory results return revealing that the patient's white blood cell count has significantly increased to 20,000 cells/uL, indicating a possible infection. His C-reactive protein (CRP) level is elevated at 6.8 mg/L, further supporting the suspicion of an inflammatory response. The blood cultures drawn earlier confirm the presence of Streptococcus pneumoniae, a common pathogen in patients with Sickle Cell Anemia and a cause of sepsis and meningitis. A lumbar puncture is performed, and the cerebrospinal fluid (CSF) analysis reveals neutrophilic pleocytosis, decreased glucose, and increased protein, consistent with bacterial meningitis.

Change in Patient Status:

Despite aggressive management, the patient's condition rapidly declines. His mental status continues to deteriorate, with increasing periods of lethargy and disorientation. His respiratory status also worsens, with a respiratory rate increasing to 36 breaths per minute and oxygen saturation dropping to 72% on 4L nasal cannula. The patient also starts to exhibit signs of reduced urine output (<0.5 mL/kg/hr), suggesting possible acute kidney injury (AKI) secondary to sepsis. The combination of severe hypoxemia, possible sepsis-induced AKI, and confirmed meningitis necessitates the escalation of care, including possible intubation and transfer to an intensive care unit (ICU) for advanced monitoring and management.

Section 4

New Complications:

Despite aggressive treatment measures, the patient experiences a grand mal seizure, a complication related to his bacterial meningitis. Post-seizure, his Glasgow Coma Scale (GCS) score decreases to 7, indicating a significant decrease in consciousness level. He also develops a new onset fever of 39.7°C, further suggestive of the systemic inflammatory response to the severe infection. Meanwhile, his hemoglobin levels drop from 9 g/dL to 6.5 g/dL, raising concerns about possible acute chest syndrome, a life-threatening complication of Sickle Cell Anemia characterized by vaso-occlusive crisis in the pulmonary vasculature.

Response to Interventions:

The patient's worsening condition prompts immediate intervention. He is intubated for airway protection due to his decreasing GCS score and for better oxygenation. His oxygen saturation improves to 90% on a FiO2 of 0.8. He is started on broad-spectrum antibiotics, including ceftriaxone and vancomycin, to combat the Streptococcus pneumoniae infection. A chest X-ray is ordered to assess for acute chest syndrome. He is also given a transfusion of packed red blood cells to address his low hemoglobin levels. Despite these interventions, the patient remains in a critical state, and the healthcare team prepares for the potential need for dialysis due to his ongoing low urine output and risk of worsening AKI.

Section 5

New Diagnostic Results:

The results from the chest X-ray come back, revealing diffuse pulmonary infiltrates, a classic sign of acute chest syndrome. His arterial blood gas (ABG) analysis shows a pH of 7.28, PaO2 of 55 mmHg, and PaCO2 of 60 mmHg. These values are indicative of severe respiratory acidosis, aligning with his clinical picture of acute chest syndrome. Additionally, his blood cultures return positive for Streptococcus pneumoniae, confirming the suspicion of bacterial meningitis.

Change in Patient Status:

Despite the interventions, the patient’s condition continues to deteriorate. His fever spikes to 40.2°C, and he becomes more tachycardic with a heart rate now in the 130s. His blood pressure begins to drop, with readings now consistently below 90/60 mmHg. The patient's renal function worsens, with his creatinine rising to 3.2 mg/dL and a continued decrease in urine output. This scenario, coupled with the patient's rising lactate levels (4.5 mmol/L), raises the concern of septic shock secondary to bacterial meningitis and acute chest syndrome. His hemoglobin levels remain low at 6.3 g/dL, despite the transfusion. The healthcare team recognizes these signs of multiorgan failure and acknowledges the necessity of rapidly escalating care to prevent further deterioration.