cellulitis - Nursing Case Study

Pathophysiology

• Primary mechanism: Cellulitis typically begins with a breach in the skin barrier, allowing bacteria, commonly Streptococcus or Staphylococcus, to enter the dermis and subcutaneous tissues, triggering an inflammatory response characterized by redness, warmth, and swelling.

• Secondary mechanism: As the infection progresses, bacterial toxins and enzymes, such as hyaluronidase, facilitate the spread of bacteria by breaking down connective tissue, leading to extensive tissue inflammation and potential systemic involvement.

• Key complication: If untreated, cellulitis can lead to sepsis, characterized by a systemic inflammatory response that may result in organ dysfunction and requires urgent medical intervention.

Patient Profile

Demographics:

35-year-old female, office worker

History:

• Key past medical history: Type 2 diabetes mellitus, hypertension

• Current medications: Metformin, Lisinopril

• Allergies: Penicillin

Current Presentation:

• Chief complaint: Red, swollen, and painful area on the lower left leg

• Key symptoms: Increasing redness and warmth, mild fever, fatigue, slight difficulty walking due to pain

• Vital signs: Temperature 38.3°C (100.9°F), Heart rate 95 bpm, Blood pressure 145/90 mmHg, Respiratory rate 20 breaths per minute

Section 1

New Diagnostic Results:

Following the initial assessment, the patient was admitted for further evaluation and treatment. Laboratory tests, including a complete blood count (CBC), C-reactive protein (CRP), and blood cultures, were ordered to assess the extent of the infection and any systemic involvement. The CBC revealed leukocytosis with a white blood cell count of 15,000/mm³, indicating an inflammatory response. Her CRP level was significantly elevated at 80 mg/L, suggesting acute inflammation. Blood cultures were taken to identify any bacteremia, though results are still pending.

A Doppler ultrasound of the affected leg was performed to rule out deep vein thrombosis (DVT), given the patient's symptoms and risk factors. The ultrasound showed no evidence of DVT but confirmed subcutaneous edema consistent with cellulitis. In addition, a comprehensive metabolic panel (CMP) revealed mild renal impairment with a creatinine level of 1.5 mg/dL, likely secondary to dehydration and increased metabolic demand from the infection. This finding necessitates careful monitoring of renal function, especially considering her hypertension and diabetes, as these conditions may complicate fluid management and antibiotic therapy.

These diagnostic results highlight the need for prompt and targeted intervention to prevent further complications. The elevated CRP and leukocytosis indicate a robust inflammatory response, necessitating the initiation of broad-spectrum antibiotics that do not include penicillin due to the patient's allergy. The pending blood culture results will guide further antibiotic adjustments. The renal impairment requires close monitoring of fluid balance and renal function tests, reinforcing the importance of a multidisciplinary approach to manage the complexities of her condition effectively. These findings will inform the next steps in her care, emphasizing the need for vigilant observation for any signs of systemic involvement or deterioration.

Section 2

As the treatment progresses, the patient's status is closely monitored for any changes that could indicate complications. On the third day of admission, the patient begins to exhibit signs of increased pain and swelling in the affected leg, accompanied by a low-grade fever of 38.3°C (100.9°F). Despite the initiation of broad-spectrum antibiotics, there is minimal improvement in her symptoms, raising concerns about potential antibiotic resistance or an atypical organism. Her blood pressure remains stable at 135/85 mmHg, but her heart rate has increased to 102 bpm, suggesting possible systemic stress.

Repeat laboratory tests reveal a persistent leukocytosis with a white blood cell count now at 17,500/mm³, and CRP levels remain elevated at 75 mg/L. These findings, coupled with her clinical presentation, suggest that the infection is not being adequately controlled. Furthermore, the pending blood culture results return positive for methicillin-resistant Staphylococcus aureus (MRSA), necessitating a change in the antibiotic regimen to include vancomycin, an antibiotic effective against MRSA.

Concurrently, a repeat CMP indicates that the patient's renal function has deteriorated further, with a creatinine level rising to 1.8 mg/dL. This worsening renal impairment underscores the need to adjust the dosing of vancomycin and calls for careful fluid management to avoid fluid overload while maintaining adequate renal perfusion. The healthcare team, including infectious disease specialists and nephrologists, collaborates to refine the treatment plan. The patient is placed on a strict input-output monitoring protocol to balance hydration needs and prevent further renal compromise. This development highlights the complexity of managing cellulitis with systemic involvement and resistant organisms, prompting ongoing clinical reasoning to optimize therapeutic outcomes and prevent further complications.

Section 3

On the fifth day of admission, the healthcare team notes a concerning change in the patient's status. Despite the initiation of vancomycin therapy and adjustments to her fluid management plan, the patient reports increasing fatigue and shortness of breath. Upon examination, her respiratory rate has increased to 24 breaths per minute, and she appears mildly cyanotic with an oxygen saturation of 91% on room air, necessitating supplemental oxygen. Auscultation of the lungs reveals diminished breath sounds bilaterally, with fine crackles present at the lung bases, raising suspicion of fluid overload or early acute respiratory distress syndrome (ARDS).

Given these new developments, a chest X-ray is ordered, revealing bilateral infiltrates consistent with pulmonary edema. These findings suggest that despite careful fluid management, the patient may be experiencing a complication related to fluid overload, possibly exacerbated by underlying renal insufficiency. The nephrology team evaluates the patient and recommends further diuretic therapy to manage fluid balance carefully, while also considering the need for potential renal replacement therapy if renal function continues to decline.

The clinical team convenes to reassess the patient's care plan, focusing on optimizing her respiratory status and monitoring for signs of worsening renal function. They decide to continue vancomycin with close monitoring of trough levels to ensure therapeutic efficacy without contributing to nephrotoxicity. This situation underscores the importance of vigilant monitoring and timely intervention in managing complex cases of cellulitis with systemic involvement, as well as the necessity for ongoing interprofessional collaboration to address evolving complications effectively.

Section 4

Two days following the nephrology team’s intervention with diuretic therapy, the patient’s condition continues to evolve. Repeat laboratory tests reveal a significant increase in serum creatinine levels to 2.1 mg/dL from a baseline of 1.2 mg/dL, indicating worsening renal function. Blood urea nitrogen (BUN) has also risen to 38 mg/dL. Electrolyte panels show mild hyperkalemia with a potassium level of 5.6 mmol/L. The patient complains of persistent nausea and generalized muscle weakness, which could be attributed to the electrolyte imbalance and ongoing renal issues. Close monitoring of renal function is now crucial as these changes suggest a progression towards acute kidney injury, overshadowing the initial cellulitis management.

Despite the implementation of diuretics, the patient’s pulmonary status shows minimal improvement. Oxygen saturation remains at 92% with 2L supplemental oxygen via nasal cannula. Respiratory therapy notes a slight improvement in breath sounds but reports continued crackles at the lung bases. A follow-up chest X-ray still shows bilateral infiltrates, consistent with pulmonary edema, and highlights the need for more aggressive fluid management. The team deliberates the potential need for initiating renal replacement therapy to offload excess fluid and address the renal insufficiency.

The clinical team’s focus shifts to fine-tuning the balance between diuresis and potential nephrotoxicity from vancomycin. They decide to consult with the infectious disease team to explore alternative antibiotic regimens that are less nephrotoxic while maintaining efficacy against the suspected pathogens. The patient’s status warrants ongoing multidisciplinary collaboration to mitigate the risk of further complications and facilitate a gradual recovery. This complex interplay of renal and pulmonary management underscores the critical role of comprehensive assessment and dynamic care planning in the face of escalating complications.

Section 5

The clinical team decides to prioritize a new assessment of the patient's evolving condition. Upon examination, the patient shows signs of increased respiratory distress, with a respiratory rate now elevated to 26 breaths per minute and shallow breathing patterns. The supplemental oxygen has been increased to 3L via nasal cannula to maintain an oxygen saturation of 91%, indicating a concerning trend in pulmonary function. Auscultation reveals persistent crackles at the lung bases, and the patient reports feeling more short of breath and fatigued compared to the previous day. These signs suggest that the pulmonary edema may be worsening, prompting immediate consideration for more intensive interventions.

The nephrology team is consulted again to address the worsening renal function and the potential need for renal replacement therapy. In light of the rising serum creatinine, now at 2.3 mg/dL, and persistent hyperkalemia of 5.8 mmol/L, the nephrology team discusses the initiation of dialysis as a means to manage both fluid overload and electrolyte imbalances. Additionally, a repeat electrolyte panel highlights a further decrease in bicarbonate levels to 19 mmol/L, indicating metabolic acidosis, which could contribute to the patient's respiratory distress.

In parallel, the infectious disease team recommends switching from vancomycin to linezolid, a less nephrotoxic antibiotic, to continue addressing the cellulitis without exacerbating renal insufficiency. This adjustment aims to alleviate the burden on the kidneys while maintaining adequate antimicrobial coverage. The patient's care plan is updated to reflect these changes, and close monitoring is emphasized to reassess the patient's response to the modified therapeutic strategy. The multidisciplinary team remains vigilant, ready to adapt the management plan in response to any new developments, underscoring the complexity and interconnectedness of the patient's condition.