What is the diagnosis for a patient with a chest X-ray showing mild vascular congestion versus peribronchial thickening, normal troponin (Troponin) and D-dimer (D-dimer) levels, hyperglycemia (glucose 297), and normal renal function (creatinine 0.69)?

From the Guidelines

The patient's presentation suggests a need for careful assessment of volume status and management of hyperglycemia, with consideration of symptomatic treatment for possible bronchitis and gentle diuresis if fluid overload is suspected. Given the chest X-ray findings of mild vascular congestion versus peribronchial thickening of lower airway disease such as bronchitis, and the laboratory results, including a glucose level of 297 mg/dL, it is crucial to prioritize the management of hyperglycemia. According to the 2016 ESC guidelines for the diagnosis and treatment of acute and chronic heart failure 1, careful clinical evaluation is mandatory to select further management, and symptoms and signs of heart failure reflect fluid overload or reduced cardiac output. The normal troponin (0.01) and D-dimer (0.27) suggest no acute cardiac injury or pulmonary embolism, as indicated by the absence of elevated biomarkers and normal coagulation studies. The creatinine of 0.69 indicates normal kidney function, which is reassuring for medication clearance. For the respiratory findings, if bronchitis is suspected, consider symptomatic treatment with bronchodilators such as albuterol 2.5 mg via nebulizer every 4-6 hours as needed, adequate hydration, and possibly antibiotics if bacterial infection is suspected based on clinical presentation. The guidelines also recommend that initial diagnosis of acute heart failure (AHF) should be based on a thorough history, physical examination, and further confirmed by appropriate additional investigations such as ECG, chest X-ray, laboratory assessment, and echocardiography 1. In terms of specific management, starting with subcutaneous insulin or an insulin drip if severely symptomatic, with the goal of gradually reducing glucose to 140-180 mg/dL, is a reasonable approach. Additionally, gentle diuresis with furosemide 20-40 mg IV may be appropriate if fluid overload is suspected, considering the patient's volume status and the absence of signs of hypoperfusion, as defined in the guidelines 1. These interventions address both the potential lower airway disease and the metabolic derangement, which likely contribute to the patient's current condition. Key considerations include:

• Monitoring the patient's volume status and adjusting diuretic therapy as needed
• Adjusting the insulin regimen based on glucose levels and the patient's response to treatment
• Considering the use of bronchodilators and antibiotics if bronchitis is suspected
• Evaluating the need for further diagnostic testing, such as echocardiography, based on the patient's clinical presentation and response to initial treatment.

From the Research

Patient's Condition

The patient's chest x-ray shows mild vascular congestion versus the peribronchial thickening of lower airway disease, such as bronchitis. The patient's volume status should be correlated with these findings.

• No pleural effusion is present
• No pneumothorax is present
• Troponin levels are at 0.01, and d-dimer levels are at 0.27
• CMP shows glucose at 297 and creatinine at 0.69

Relevant Studies

Studies have shown that lower respiratory tract infections can be caused by various factors, including viral and bacterial infections 2, 3, 4, 5.

• A study published in 2006 found that clinical and radiological signs cannot be reliably used to identify the causative germ in lower respiratory tract infections 2.
• Another study published in 2001 found that most patients who consult with acute lower respiratory symptoms receive antibiotics, usually without evidence of significant infection 3.
• A 2019 study noted that acute bronchitis is typically viral and that antibiotics are not indicated in patients without chronic lung disease unless Bordetella pertussis infection is suspected 4.
• The effect of nebulized albuterol on blood glucose in patients with diabetes mellitus with and without cystic fibrosis was studied in 2005, and it was found that albuterol causes no clinically significant increases in blood glucose in these patients 6.

Management and Diagnosis

The diagnosis of lower respiratory tract infections, such as acute bronchitis and pneumonia, is based on symptoms and imaging study results 4.

• Severity scoring systems are used to aid clinical judgement in selecting inpatient versus outpatient management 4.
• Antibiotics should be administered according to current guidelines 4.
• Ultrasonography is more accurate than chest x-rays in diagnosing community-acquired pneumonia (CAP) 4.
• Advances in diagnostic testing have improved our ability to detect pathogens, including viral pathogens, which are important causal pathogens in immunocompetent patients 5.