PNEUMONIA

PNEUMONIA

DEFINITIONPneumonia is an acute inflammation of the lung parenchyma caused by a microbial organism.INCIDENCEPneumonia is associated with significant morbidity and mortality.About 90% of ARTI deaths are due to pneumonia.In developed countries, incidence of pneumonia is low as 3% to 4% In developing countries, it is high as 20% to 30%. ETIOLOGYBacteria,viruses,mycoplasma, fungal agents,and protozoa. Streptococcus pneumoniae (major cause). Staphylococcus aureus Mycoplasma pneumoniaeAspiration of food,fluid,vomitus or from inhalation of toxic or caustic chemicals,smoke,dusts, or gases.Complication of immobility and chronic illness.

Factors predisposing to pneumoniaAdvanced ageHistory of smokingAir pollutionAltered consciousness: alcoholism, haed injury,seizures, anaesthesia, drug overdose,stroke,Altered oropharyngeal flora secondary to antibiotics.Bed rest and prolonged immobility.Chronic diseases: chronic lunf disease,DM,heart disease,cancer,ESRD.Deblitating illnessHIV infection

Factors predisposing to pneumonia..Immunosuppressive drugs: corticosteroids,cancer chemotherapy,immunosuppressive therapy after organ transplant.Intestinal and gastric feedings via nasogastric and nasointestinal tubes.MalnutritionTracheal intubationURTI

TYPES OF PNEUMONIAOn the basis of area involved, segmental pneumonia lobar pneumonia bilateral pneumoniaOn the basis of location and radiologic appearance, bronchopneumonia Interstitial pneumonia Alveolar pneumonia Necrotising pneumoniaAccording to causative organisms, community acquired pneumonia Hospital acquired pneumonia fungal pneumonia aspiration pneumonia opportunistic pneumoniaANATOMY AND PHYSIOLOGY

PATHOPHYSIOLOGYPneumococal pneumonia is the most cause of bacterial pneumonia and is caused by the Streptococus pneumoniae organism.The organism is generally found in the nose and throat. When it invades the lungs, pneumonia can occur.

There are 4 characteristic stages of disease process.1. Congestion2. Red hepatization3. Grey hepatization4. ResolutionCongestion: After the pneumococcus organism reach the alveoli, there is an outpouring of fluid into the alveoli.The organism multiply in the serous fluid ,and the infection is spread.The pneumococci damage the host by their overwhelming growth and by interfering with lung function.2. Red Hepatization: There is massive dilation of the capillaries, and alveoli are filled with organisms,neutrophils, RBCs and fibrin.The lungs appear red and granular, similar to liver, which is why the process is called hepatization. 3. Gray hepatization:Bloodflow decreases and leukocytes and fibrin consolidates in the affected part of the lung.

4. Resolution:Complete resolution and healing occurs if there are no complications.The exudate becomes lysed and is processed by the macrophages.The normal lung tissue is restored and the persons gas-exchange ability returns to normal.PathophysiologyResolution of InfectionRed Hepatization and consolidation of lung parenchyma.Inflammatory responseAttraction of neutrophils,release of inflammatory mediators, accumulation of fibrinous exudates,RBCs and bacteria.Gray hepatization & deposition of fibrin and pleural surfaces.Phagocytosis in alveoliAspiration of S.pneumoniaeRelease of bacterial endotoxinMacrophages in alveoli ingests and remove neutrophils,fibrin & bacteria.Leukocyte infiltration18CLINICAL FEATURESSudden onset of symptoms:FeverShaking chillsShortness of breathProductive cough of purulent sputum (rust coloured sputum in pneumococal pneumonia)Pleuritic chest painConfusion and stupor, in elderly patients.Signs of pulmonary consolidation:Dullness to percussionIncreased fremitusBronchial breath soundsCrackles.Pneumonia may manifest atypically with a more gradual onset. Symptoms includes:- Dry cough, extrapulmonary manifestations such as headache, myalgia, fatigue, sore throat, nausea, vomiting and diarrhoea.

COMPLICATIONSPLEURISY: Inflammation of the Pleura.PLEURAL EFFUSION: transudate fluid in the pleural space.ATELECTASIS: Collapsed, airless alveoli.BACTEREMIA: Bacterial infection in the blood.LUNG ABSCESS: seen in pneumonia caused by S.aureus and gram negative pneumonia.EMPYEMA: Accumlation of exudate in the pleural cavity.PERICARDITIS: Results from spread of infecting organisms from infected pleura or via hematogenous route to the pericardium.MENINGITIS: caused by S.pneumonia.ENDOCARDITIS: can develop when the organisms attack the endocardium and the valves of the heart.

DIAGNOSTIC STUDIESHistory and physical examinationChest X-ray: shows typical pattern characteristics of the infecting organism and is vulnerable in diagnosis.Lobar or segmental consolidation suggests bacterial cause.Diffuse pulmonary infiltrates are caused by infection with viruses or pathogenic fungi. cavity shadows suggests the presence of necrotising infection with destruction of lung tissue.Gram stains and cultures of sputum: LRT sputum specimen for culture is recommended before initiating antibiotic therapy.ABG analysis: reveals hypoxemia, hypercapnia and acidosis.CBC, differential and routine blood chemistries: leukocytosis in majority of cases. WBC > 15000/cmmBlood cold agglutinin testUrine streptococcus pneumonia antigenUrine legionella neumophilia rapid test.USG Abdomen and bilateral venous doppler.MANAGEMENTCOLLABORATIVE MANAGEMENTPrompt treatment with appropriate antibiotic s almost cures bacterial and mycoplasma pneumonia.In uncomplicated cases, the patients responds to drug therapy with in 48-72 hrs.Supportive measures include:Oxygen therapyAnalgesicsantipyretics

For viral pneumonia, two antiviral drugs: - amantidine - rimantadine. Are approved for use within 48hrs of onset of symptoms in the treatment of Influenza-A virus.The neuraminase inhibitors, Zanamivir and oseltamir are active against both Influenza A and B. VACCINATION: mainstay of preventionBoth inactivated influenza vaccine and live attenuated vaccines can be used.LAIV (Flumist) is an intravenously administered vaccine only for person aged 5-49 yrs.Pneumococcal vaccines: 50% to 80% effective in preventing bacteremic pneumococcal disease.

Nutritional therapyFluid intake of atleast 3L/day for supportive treatment.If oral intake cannot be maintained, IV administration of fluids and electrolytes may be necessary for acutly ill patients.Small and frequent meals are better tolerated by the dyspneic patient.NURSING MANAGEMENT