PNEUMONIA

INTRODUCTION: Pneumonia is an inflammation of the lung parenchyma caused by various microorganisms, including bacteria, mycobacteria, fungi, and viruses. Pneumonias are classified as community acquired pneumonia (CAP), hospital-acquired (nosocomial) pneumonia (HAP), pneumonia in the immunocompromised host, and aspiration pneumonia. There is overlap in how specific pneumonias are classified, because they may occur in differing settings. Those at risk for pneumonia often have chronic underlying disorders, severe acute illness, a suppressed immune system from disease or medications, immobility, and other factors that interfere with normal lung protective mechanisms. The elderly are also at high risk.

PATHOPHYSIOLOGY: An inflammatory reaction can occur in the alveoli, producing an exudate that interferes with the diffusion of oxygen and carbon dioxide; Oxygen; Carbon dioxide  bronchospasm may also occur if the patient has reactive airway disease. Bronchopneumonia, the most common form, is distributed in a patchy fashion extending from the bronchi to surrounding lung parenchyma. Lobar pneumonia is the term used if a substantial part of one or more lobes is involved. Pneumonias are caused by a variety of microbial agents in the various settings. Common organisms include Pseudomonas aeruginosa and Klebsiella species; Staphylococcusaureus; and entericGram-negative bacilli, and viruses.

CLINICAL MANIFESTATIONS: Clinical features vary depending on the causative organism and the patient’s disease. Sudden chills and rapidly rising fever of a temperature raising from 38.5⁰C to 40.5⁰C. Pleuritic chest pain aggravated by respiration and coughing. Severely ill patient has marked tachypnea (25 to 45 breaths/min) and dyspnea; orthopnea when not propped up. Pulse rapid and bounding; may increase 10 beats/min per degree of temperature elevation. A relative bradycardia for the amount of fever suggests viral infection, mycoplasma infection, or infection with a Legionella organism.

OTHER SIGNS: upper respiratory tract infection, headache, low-grade fever, pleuritic pain, myalgia, rash, and pharyngitis; after a few days, mucoid or mucopurulent sputum is expectorated.

SEVERE PNEUMONIA: flushed cheeks; lips and nail beds demonstrating central cyanosis. Sputum purulent, rusty, blood-tinged, viscous, or green depending on etiologic agent. Appetite is poor, and the patient is diaphoretic and tires easily. Signs and symptoms of pneumonia may also depend on a patient’s underlying condition for example, different signs occur in patients with conditions such as cancer, and in those who are undergoing treatment with immunosuppressants, which decrease the resistance to infection.

ASSESSMENT AND DIAGNOSTIC METHODS: Primarily history, physical examination. Chest x-rays, blood and sputum cultures, Gram stain.

MEDICAL MANAGEMENT: Antibiotics are prescribed on the basis of Gram stain results and antibiotic guidelines including resistance patterns, risk factors, etiology must be considered. Combination therapy may also be used. Supportive treatment includes hydration, antipyretics, antitussive medications, antihistamines, or nasal decongestants. Bed rest is recommended until infection shows signs of clearing. Oxygen therapy is given for hypoxemia. Respiratory support includes high inspiratory oxygen concentrations, endotracheal intubation, and mechanical ventilation. For groups at high risk for CAP, pneumococcal vaccination is advised.

RELATED;

1.  TUBERCULOSIS

2.  ASTHMA

3.  ACUTE RESPIRATORY DISTRESS SYNDROME

4.  MEDICAL CONDITIONS

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