Viral Pneumonia Diagnosis and Treatment

The diagnosis is supported by finding sparse bacteria and a dominance of monocytes on smears of sputum and by failing to recover a likely bacterial pathogen. Identification of the virus is usually difficult but may be important during outbreaks, among seriously ill patients, and for those with treatable viruses. Pneumonias complicating exanthematous viral infections (eg, measles, varicella, or herpes) may be tentatively diagnosed on the basis of associated clinical findings, including the rash. A specific diagnosis in most viral respiratory infections requires recovery of the virus from throat washings or tissue, identification of typical inclusions in cytopathology or biopsy specimens, or serologic assays. Most hospital laboratories do not have facilities for viral culture. The diagnosis of influenza is usually established by the presence of typical symptoms during an outbreak of disease and serologic assays of acute and convalescent sera or fluorescent antibody stain of respiratory secretions.

Your doctor will check your temperature, heart rate, and blood pressure. A small clamp, which looks like a clothespin, can be put on your finger to check your blood oxygen level. Your doctor will listen to your heart and lungs to help determine the cause of your symptoms and the severity of your illness. If it is possible that you have pneumonia, you will probably have an x-ray of your chest. Blood tests are not very helpful in diagnosing pneumonia except in special circumstances.

• Influenza A and B are usually diagnosed clinically, which means the symptoms give the diagnosis—fever, headache, body aches, tiredness, cough, runny nose. No lab tests are needed. Sometimes, secretions from your nose can be tested to help identify the organism.

• Varicella pneumonia is usually diagnosed clinically because it usually happens during an outbreak of the chickenpox.

• If your doctor suspects respiratory syncytial virus (RSV), a swab of your nose secretions can be sent for testing by a laboratory. Children and infants are more likely to be tested for RSV, because this virus can be more serious in them.

• Adenovirus and parainfluenza virus are not likely to cause life-threatening illness. Tests are rarely done if these viruses are suspected to be the cause of pneumonia.

Viral Pneumonia Treatment

Acyclovir 5 to 10 mg/kg q 8 h for adults or 250 to 500 mg/m² BSA q 8 h for children is advocated for lung infections involving herpes simplex, herpes zoster, or varicella (chickenpox). CMV pneumonia may be treated with ganciclovir 5 mg/kg IV bid and immune globulin (IV immune globulin or CMV immune globulin) in organ transplant recipients, but this therapy has little documented benefit in patients with AIDS. (Prophylaxis and treatment of influenza are discussed in Influenza in Ch. 162.)

Some patients, especially those with influenza, develop superimposed bacterial infections that require antibiotics. Major pathogens encountered in this setting are Streptococcus pneumoniae and Staphylococcus aureus; less frequent superinfecting pathogens include Haemophilus influenzae, group A -hemolytic streptococci, and Neisseria meningitidis. Prognosis varies widely with the causative organism, the patient's age, and associated diseases; treatment is based on the pathogen.

• If you've been diagnosed with viral pneumonia, you need to rest and drink plenty of fluids.

• If you overexert yourself when you are sick, even with a virus, you can prevent your immune system from fighting off the illness, and possibly get even sicker.

• You can use over-the-counter medicines to reduce fever, body aches, and cough. Although some medicines can help you feel better, you still need rest. These medicines won't cure you, and your body still needs rest to have the energy to fight the infection and to heal itself.

• If your doctor suspects your pneumonia is caused by an influenza virus, you may get a prescription for an anti-flu medicine. It must be started within 36 hours of the beginning of symptoms to help. Four drugs are available: amantadine (Symadine), rimantadine (Flumadine), and oseltamivir (Tamiflu) are pills or capsules. Zanamivir (Relenza) is a powder that you inhale directly into your lungs.

• Varicella pneumonia is almost always serious enough to need treatment with acyclovir (Zovirax). You can take this drug by mouth or, if you are severely ill and in the hospital, by IV.

• Respiratory syncytial virus usually needs just treatment of the symptoms. If you are sick enough to be in the hospital, you might be treated with ribavirin (Rebetol).

• Treatment of adenovirus and parainfluenza virus pneumonia is also just to relieve symptoms.

• Because your lungs are weakened, your doctor may use an antibiotic to prevent you from developing a bacterial pneumonia.