Viral pneumonia: symptoms, causes, treatment
The content of the article:
- The reasons for the development of pathology
- Symptoms of viral pneumonia
- Diagnostics
- Treatment and prevention of viral pneumonia
- Complications of pneumonia
- Video
Viral pneumonia is an infection of the lower respiratory tract. The disease is acute, it is characterized by a sudden increase in body temperature, chills, intoxication syndrome, wet cough, pleural pain, respiratory failure.
The most common causative agent of the disease is the influenza virus
This form of pneumonia usually occurs during an epidemic of viral infections. A high risk is noted in people with chronic obstructive pulmonary disease, heart failure. The main nonpulmonary clinical manifestation of pathology is myocarditis.
When diagnosing pneumonia, physical, laboratory and radiological data, the relationship between pneumonia and viral infection are taken into account. Therapy is based on the use of antiviral and symptomatic agents.
Mortality from primary viral pneumonia during the 1957–1958 pandemic. reached 80%. Postmortem morphological examination revealed signs of bronchitis, tracheitis, bronchiolitis and loss of normal ciliated epithelial cells of the airways.
The reasons for the development of pathology
In 5-15% of all community-acquired pneumonia cases, viral infections are the cause, the main place of which is the influenza virus. The incubation period can range from a few hours to three days, with an average of 1–2 days. Its duration depends on various factors - the number of viral particles that entered the body, the state of immunity, the type of virus, etc.
Other possible causative agents of pneumonia: parainfluenza virus, enteroviruses, adenoviruses, respiratory syncytial virus, etc.
With the flu, it is now customary to distinguish three forms of pneumonia:
- primary viral;
- viral and bacterial;
- secondary bacterial.
The severity of the symptoms of the disease depends on the type of virus and the number of viral particles that have entered the body.
Often the viral form of pneumonia occurs in closely interacting teams (community-acquired pneumonia). A feature is that the disease develops in previously healthy individuals without background pathology. Usually infection occurs in the winter season, pneumonia can be caused by the influenza A virus, a respiratory syncytial virus.
Predisposing factors play an important role in the development of pneumonia. These include:
- age over 60 years: the danger is associated with suppression of the cough reflex, changes in microbial flora, impaired mucociliary clearance, as well as the presence of concomitant diseases;
- hypothermia: this factor should not be underestimated, since the increase in the incidence of pneumonia occurs in the winter;
- smoking: when smoking up to 15–20 cigarettes per day, there is a violation of mucociliary clearance, an increase in the chemotaxis of neutrophils and macrophages, their activation, destruction of elastic tissue, a decrease in the effectiveness of mechanical protection.
Also, the following diseases / conditions predispose to the development of pneumonia: brain injury, anesthesia, epileptic seizure, impaired consciousness, overdose of narcotic and hypnotics, alcohol intoxication.
Symptoms of viral pneumonia
A significant proportion of fatal pneumonia is not a concomitant bacterial infection, but directly the invasion and reproduction of the virus in the lungs.
The risk group for primary influenza pneumonia includes patients with immunodeficiencies, intercurrent cardiovascular diseases, children and pregnant women.
The manifestations of pathology at the initial stage are typical for influenza, however, already within 12–36 hours there is an increase in shortness of breath, which in most cases is accompanied by a cough with streaks of blood and a scant amount of sputum. Symptoms of viral pneumonia, such as pleural pain and massive hemoptysis, are less common.
At the time of hospitalization of an adult or a child, respiratory failure, tachycardia, tachypnea, cyanosis are usually pronounced.
As the disease progresses, the auscultatory picture changes. At the initial stages, crepitus is auscultated, inspiratory humming rales and sometimes dry wheezing rales are observed in the lower parts of the lungs. In the future, breathing becomes weakened, wheezing spreads to all parts of the lungs.
When the disease reaches the terminal stage, breathing and wheezing are practically not heard, while tachypnea is significant. Sometimes agitation and dyspnea are so severe that the patient cannot tolerate an oxygen mask.
In some cases, the course of the pathology may be accompanied by complications such as acute renal failure and disseminated intravascular coagulation syndrome.
With viral-bacterial pneumonia, the interval between the onset of the first respiratory symptoms and signs of involvement of the lung parenchyma in the inflammatory process is longer and can be up to 4 days. At this time, even a slight improvement in the patient's condition is possible.
Most often, this form of pathology is characterized by a productive cough with bloody or purulent sputum, severe chills and pleural pain.
At the time of hospitalization, signs of severe respiratory failure are usually clearly manifested: tachypnea, painful dyspnea, cyanosis. When conducting a physical examination, a diverse picture emerges.
In most cases, there are signs of local consolidation with involvement of the lobe or several lobes of the lungs in the process. The clinical picture is complemented by signs of massive involvement of the lung parenchyma in inflammation, which manifests itself in the form of diffuse dry inspiratory humming rales and whistling inspiratory and expiratory rales. Sometimes there are only dry whistling and buzzing rales against the background of the absence of signs of consolidation.
The X-ray picture of the lungs is a diffuse infiltrative opacification, similar to those in primary influenza pneumonia, or a combination of diffuse infiltrates with foci of focal consolidation.
Diagnostics
In the viral form of pneumonia, physical and radiological symptoms are scanty. The disease is often not recognized, even in patients with a protracted course of acute respiratory viral infections, against which there are signs of bronchial obstruction, therefore, the diagnosis is often made: residual effects of an acute respiratory viral infection.
A chest x-ray is taken to clarify the diagnosis
When diagnosing pneumonia as a nosological form, the doctor carries out a differential diagnosis with a number of diseases that manifest themselves with similar symptoms, which differ in their essence and require other treatment methods.
The main methods for verifying pneumonia pathogens are:
- microbiological examination of bronchial lavage, sputum, bronchoalveolar lavage of pleural effusion;
- microbiological blood test, including a quantitative assessment of the microflora content;
- immunofluorescent method for detecting viral components.
Laboratory studies in most patients reveal peripheral blood leukocytosis (up to 20 thousand / ml), which is associated with an increase in the content of mature neutrophils and stab forms. The main cellular elements in sputum are mononuclear cells. The existing dissociation between the cytological composition of peripheral blood and sputum is evidence in favor of primary viral pneumonia, and not secondary bacterial infection.
Chest X-ray reveals bilateral confluent infiltrative opacities that diverge from the roots of the lungs (similar to the picture of cardiogenic pulmonary edema). There may also be slight interlobar or pleural effusion.
Treatment and prevention of viral pneumonia
Currently, there is no effective therapy for primary influenza pneumonia. The use of antibiotics is ineffective except in cases of bacterial infection.
The drugs prescribed for the treatment of pneumonia with a viral etiology depend on the pathogen:
- influenza virus: Remantadin, Oseltamivir, Zanamivir;
- influenza and herpes virus: Acyclovir;
- cytomegalovirus: Ganciclovir.
It should be borne in mind that neuraminidase inhibitors - Zanamivir and Oseltamivir, as well as other antiviral drugs, are advisable to be used only within the first 24–48 hours after the onset of symptoms.
Often, the antiviral drug Amantadine is prescribed for therapy, but there is no convincing data on its benefits for pneumonia. The action of the agent is aimed at preventing the penetration of influenza A viruses into cells, therefore, it is mainly of preventive value.
In 70% of patients exposed to influenza A virus Amantadine can prevent clinical manifestations of influenza. In patients with influenza A with mild respiratory symptoms, this therapy promotes faster recovery of lung function. This drug is effective when started within the first 48 hours from the onset of the disease.
Antibiotic therapy is indicated only with a mixed nature of pneumonia or in cases of the development of purulent complications.
To facilitate the discharge of sputum, medicinal inhalations are performed
As a symptomatic treatment, antipyretic, expectorant drugs can be prescribed. In order to facilitate the discharge of sputum, drainage massage, medicinal inhalations are performed.
Complications of pneumonia
The consequences of viral and viral-bacterial pneumonia can be divided into pulmonary and extrapulmonary.
Pulmonary complications:
- acute respiratory failure (distress syndrome);
- empyema of the pleura;
- parapneumonic pleurisy;
- gangrene and lung abscess;
- broncho-obstructive syndrome;
- multiple destruction of the lungs.
Extrapulmonary complications:
- nonspecific myocarditis, endocarditis, pericarditis;
- infectious toxic shock;
- acute cor pulmonale;
- sepsis;
- anemia;
- meningitis, meningoencephalitis;
- DIC syndrome;
- psychoses (usually with severe illness, especially in elderly patients).
It is important to use personal protective equipment in closely cooperating teams during an influenza epidemic
It is important to keep in mind that flu epidemics occur almost every year, mainly in winter. Therefore, an important role is played by the prevention of the development of pneumonia, including adherence to the rules of personal hygiene, hardening, and an active and healthy lifestyle. In an epidemiologically unfavorable period, personal protective equipment should be used.
Given the specifics of the development of the disease and the possibility of serious complications, if symptoms of pneumonia appear, you should consult a doctor.
Video
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Anna Kozlova Medical journalist About the author
Education: Rostov State Medical University, specialty "General Medicine".
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