Critical Care Management of People With Fungal Infections

What Are Fungal Infections?

Fungal infections are infections caused by various several types of fungus that can impact various body parts, including the skin, hair, nails, and internal organs. In critical care patients, fungal infections are a significant cause of disease and mortality, particularly in individuals with compromised immune systems, those on broad-spectrum antibiotics, or those undergoing immunosuppressive therapy. Aspergillosis, candidiasis, and mucormycosis are examples of invasive fungal infections that can cause serious infections that can damage several organs and call for extensive treatment.

The treatment of critical patients with fungal infections patients is equally important and can be achieved through measures such as hand hygiene, environmental cleaning, and the use of antifungal prophylaxis in high-risk patients. The judicious use of antibiotics and immunosuppressive agents can also reduce the risk of fungal infections in critically ill patients.

What Are the Causes of Fungal Infections in Critical Care Patients?

There are several causes of fungal infections in critical care patients, which are as listed:

• Host Factors: Immunosuppression, such as that brought on by AIDS (acquired immunodeficiency syndrome), hematologic malignancies, solid organ transplantation, and long-term corticosteroid usage are host variables that raise the risk of fungal infections in critical care patients. Neutropenia (low neutrophil count in the blood), malnutrition, and underlying lung diseases are additional host variables.

• Hospital-Related Factors: The use of invasive medical devices, such as central venous catheters, urine catheters, and mechanical ventilation, are environmental factors that lead to the development of fungal infections in critical care patients. These can serve as a point of entry for fungi into the body. Long-term hospitalization, broad-spectrum antibiotic use, and contact with contaminated water or soil are among other environmental risks.

What Are the Common Fungal Infections in Critical Care Patients?

According to the American College of Chest Physicians (ACCP), the most common fungal infections encountered in critical care settings are candidemia and invasive aspergillosis. Candidemia is often associated with the use of central venous catheters, while invasive aspergillosis is associated with prolonged hospitalization, neutropenia, and the use of corticosteroids or other immunosuppressive agents. Other less common fungal infections that may occur in critical care patients include cryptococcosis, histoplasmosis, blastomycosis, and mucormycosis.

What Are the Clinical Manifestations of Fungal Infections in Critical Care Patients?

The clinical manifestations of fungal infections in critical care patients can vary depending on the type of infection and the site of infection. Common symptoms of fungal infections in critical care patients include fever, chills, and malaise. Other signs and symptoms may include:

• Respiratory symptoms include coughing and loss of breath, chest pain, etc.

• Changes in vision.

• Gastric disturbances like nausea, and vomiting.

• Swelling of the skin or drainage at the site of infection.

• Neurological signs such as seizures and a change in mental state, and headaches.

How Are Fungal Infections in Critical Care Patients Diagnosed?

The diagnosis for the infections, when suspected in critical care patients, may include the following:

• Clinical Evaluation: The physicians will evaluate the patient with a suspected fungal infection including a thorough medical history, physical examination, and risk factor assessment.

• Laboratory Tests: Blood cultures, fungal cultures, antigen tests, and serologic tests are some of the commonly used laboratory tests used for the identification of fungal infections in critical care patients.

• Imaging Studies: Imaging studies, such as chest X-rays or CT (computed tomography) scans, may be used to identify the presence of fungal infections in organs or tissues.

• Molecular Diagnostic Tests: Molecular diagnostic tests, such as polymerase chain reaction (PCR) assays, can detect the presence of fungal DNA (deoxyribonucleic acid) in clinical specimens. However, access to these exams is limited, and are not yet standardized for routine clinical use.

• Biopsy: Histopathologic examination of tissue specimens obtained by biopsy or bronchoscopy can provide a definitive diagnosis of fungal infections.

What Are the Management Modalities for Fungal Infections in Critical Care Patients?

The management options for the various fungal infections for patients in critical care are based on the extent and severity of the infection. As per guidelines, the general approach is as listed:

• Candidemia: The pharmacological management of candidemia infections is by employing drugs belonging to the class of echinocandins, azoles, or Amphotericin B. The patient's clinical outcome and the underlying infection source determine how long the treatment will last. In patients with recurrent candidemia or symptoms of catheter-related infection, removal of the central venous catheter should be taken into consideration.

• Invasive Aspergillosis: Antifungal medications like Voriconazole, Isavuconazole, or liposomal Amphotericin B are frequently used to treat invasive aspergillosis. In cases with localized disease, surgical resection might be required. In some patients with advanced illnesses, corticosteroid adjunctive therapy may be recommended in specific cases.

• Mucormycosis: Therapy for mucormycosis typically involves treatment with liposomal Amphotericin B. For aggressive infections, invasive surgical removal of infected tissue may be carried out. In some cases, adjunctive therapy using hyperbaric oxygen may be recommended.

• Cryptococcosis: Antifungal therapy, such as Amphotericin B and Flucytosine, is frequently used to treat cryptococcosis. This is followed by consolidation therapy using Fluconazole or another azole antifungal agent. It is crucial for patients with cryptococcal meningitis (inflammation of the outer covering of the brain) to manage high intracranial pressure with the proper medication and surgical interventions.

• Histoplasmosis: Treatment of these infections typically involves the use of antifungal therapy, such as Itraconazole, Fluconazole, or Amphotericin B, depending on the severity of the disease and the patient's clinical response.

The management of fungal infections in critical care patients ought to additionally involve supportive care practices, including managing organ failure and electrolyte imbalances in addition to antifungal therapy. In severely ill patients who may have reduced organ function, close monitoring for adverse effects of antifungal medication, such as kidney and liver toxicity, is important.

Conclusion

Fungal infections are a significant cause of morbidity and mortality in critically ill patients. Despite advances in diagnostic techniques and antifungal therapy, the management of these infections remains challenging. Critical care management of people with fungal infections requires a multidisciplinary approach involving infectious disease specialists, microbiologists, and critical care physicians. The mainstay of treatment is the prompt initiation of antifungal therapy, guided by diagnostic tests such as blood cultures, fungal cultures, antigen tests, and histopathologic examination. In addition, supportive care, including fluid and electrolyte management, hemodynamic support, and respiratory support, is essential for the successful management of critically ill patients with fungal infections.