Pneumonia: Causes, Symptoms, Diagnosis & Treatment
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| Pneumonia |
Pneumonia
Pneumonia refers to the inflammation/swelling of your lung parenchyma, the alveoli as opposed to the bronchi or bronchioles in one or both lungs. It is an infection of your lower respiratory tract.
Pneumonia is clinically manifested by cough, shortness of breath, raised respiratory rate, fever, inability to feed, and tachycardia.
Pneumonia is a highly contagious disease. It can be easily transmitted from one person to another person through droplet infection. When a person with pneumonia talks, laughs, spits, sneezes, and coughs, droplets hang in the air. If a healthy person inhales these droplets, he will also get the disease.
Pneumonia is characterized by consolidation. Consolidation is a pathological process where the alveoli are loaded up with a combination of fiery exudates. Types Of Pneumonia
Causes Of Pneumonia
Pneumonia is caused by various infectious agents like viruses, fungi, and bacteria. Bacterial pneumonia is caused by the most common bacteria, Streptococcus pneumoniae. Likewise, viral pneumonia is caused by Haemophilus pneumonia in most cases.
Pneumonia is most commonly caused by bacteria such as Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, P.aeruginosa, staphylococcus aureus, and Klebsiella pneumoniae.
Mycoplasma pneumoniae, chlamydophila pneumonia, legionella pneumophila, Coxiella burnetii, Chlamydia psittaci, Escherichia coli, and streptococci viridans are also involved in causing pneumonia.
Commonly involved viruses in causing pneumonia are influenza virus, adenovirus, and cytomegalovirus. The most common fungi involved in causing pneumonia include fungi pneumocystis jirovecii and pneumocystis Carini.
Pathogenesis Of Pneumonia
The development of pneumonia requires a pathogen that reaches the alveoli so that the host defenses are overwhelmed by micro-organism virulence. The endogenous sources of microorganisms are nasal carriers, sinusitis, gastric or tracheal colonization, hematogenous spread, and other external sources of contamination such as intensive care unit workers and bronchoscopy must be considered accidental.
Once the pathogen arrives at the alveoli, then the next step is based on the interaction between the invading bacteria and alveolar macrophages. Bacteria may overcome the alveolar macrophages and multiply in the alveolar space. Then in response to the uncontrolled multiplication, alveolar macrophages will produce cytokines that are an inflammatory response. This inflammatory response either can remain localized or become systemic.
Macrophages release cytokines which results in an increase in mucus production, and constriction of local and systemic vessels. This increase in mucus is associated with symptoms such as cough and sputum production. This inflammation results in the production of exudate that obstructs the air spaces, preventing the exchange of gases that is characteristic of pneumonia. If TNF-α and IL6 are released systemically, then the symptoms become more severe and may include hypotension and organ dysfunction.
Symptoms Of Pneumonia
In pneumatic patients, there are two types of signs and symptoms such as
- Respiratory signs and symptoms
- Non-Respiratory signs and symptoms
Respiratory Sign And Symptoms
- Cough: In pneumococcal pneumonia, initially it is a dry cough which is also called a non-productive cough but later it produces blood-stained or rust-colored sputum which is called a productive cough. A productive cough is a noisy, sudden expulsion of air from the lungs that removes sputum from the respiratory tract and permits air to reach to alveoli of the lungs. Bronchopneumonia presents more non-specifically with a productive cough. Atypical pneumonia is clinically characterized by a dry cough
- Shortness of breath or difficulty breathing. It is also called dyspnea.
- Respiratory rate: The normal value of respiratory rate depends on age, health, and recent activity. In pneumatic patients, the respiratory rate is usually raised. After age 12, most adults continue to breathe within this normal range which is 12-20 breaths/minute.
- Breath sounds: In pneumatic patients, breath sounds may be diminished. Rales or rhonchi may be heard. Rales or rhonchi are low-pitched sounds.
Non-Respiratory Signs and Symptoms
- Fever: The temperature of pneumatic patients may increase or decrease from baseline but most often it is increased. It may remain sustained or intermittent.
- Fatigue
- Sweats
- Headaches
- Leukocytosis: It is the above-normal range of white blood cells
- Leukopenia (deficiency of white blood cells)
- Mental status change: In patients with pneumonia, mental status changes such as confusion or lethargy (lack of energy or laziness) may occur.
- Chest pain: Chest pain is caused by pleurisy (inflammation of pleura) and pneumothorax (air in pleural space)
- The decline in oxygen saturation
- Inappropriate ADH hormone secretion
- Hyponatremia (low level of sodium in the blood)
- Patchy consolidation in both lungs
- Abnormalities in liver enzymes
Diagnosis Of Pneumonia
Diagnostic tests used for pneumonia may include the following,
Sputum Gram Stain Test
Gram sputum stain is neither delicate nor explicit for streptococcus pneumoniae. Likewise, it is also used to discover streptococcus aureus and gram-negative poles.
Blood Cultures
It is done in a large portion of the cases yet is not dependable on tests.
The Arterial Blood Gasses (ABG) Test
ABC test is utilized to check the seriousness of the ailment. It is utilized to check the seriousness of sickness and partial pressure of oxygen and carbon dioxide and the corrosive base level of the blood.
Urinary Antigen Test
Urinary antigen tests for Legionella pneumophila and Streptococcus pneumoniae are at any rate as touchy and explicit as sputum gram mess and culture. Results of urinary antigen tests are immediate and are not influenced by starting antimicrobial treatment. The method utilized is the Immuno chromatography procedure (ICT).
Rapid Flu Testing
It has transitional affectability yet high explicitness. Positive outcomes may diminish superfluous antibacterial use.
Other Tests
These incorporate bronchoscopy, lung biopsy, and so on, they are utilized once in a while as they are exceptionally unsafe. They are possibly utilized when the etiology is essential for finding.
Imaging Techniques
They include chest radiography, Ct-scan, and ultrasonography. They are used to check the opacities and lobular effusion etc. Chest imaging may help assess the severity of the disease and the response of therapy over time.
Treatment Of Pneumonia
There is a different treatment approach used for patients who are not hospitalized or who are hospitalized.
Treatment Plan For Not Hospitalized Patients
The treatment plan for not hospitalized pneumonia patients consists of macrolides such as azithromycin, clarithromycin, and erythromycin. Erythromycin and clarithromycin are preferred choices because dose-dependent effects are bacteriostatic at low concentrations and bactericidal at high concentrations.
Food increases the absorption of clarithromycin while decreasing the absorption of other members of this class. The antibacterial spectrum is like penicillin. That’s why it can be given to patients who are allergic to penicillin. Adverse effects of macrolides are nausea, vomiting, and elevated liver enzymes which lead to hepatotoxicity. The standard dose is 800mg for 7-10 days.
In penicillins, we prefer methicillin and amoxicillin because they are useful against mycoplasma and chlamydia pneumonia. They shorten the duration of atypical pneumonia and community-acquired pneumonia. Adverse effects of penicillin are hypersensitivity, nephrotoxicity, nephritis, and cationic toxicity. The standard dose is 250mg-2g.
Treatment Plan For Hospitalized Patients
Hospitalized patients with pneumonia are divided into two categories.
- Non-intensive care units
- Intensive care units patients
For Non-Intensive-Care Unit Patients
Drugs preferred for the treatment of non-intensive care units patients are fluoroquinolones (ciprofloxacin, levofloxacin, moxifloxacin, gatifloxacin, and gatifloxacin). These fluoroquinolones are also called respiratory fluoroquinolones.
Levofloxacin, ciprofloxacin, and moxifloxacin are used against streptococcus pneumonia. They have a long half-life and are used against multi-drug-resistant organisms. They shorten the duration of nosocomial and community-acquired pneumonia.
Levofloxacin, Gemifloxacin, gatifloxacin, and moxifloxacin have long half-lives which permit once-daily dosing. Adverse effects are GIT upset, dizziness, and photosensitivity. They are contraindicated with digoxin, warfarin, and ergot. Doses for pediatrics are (10-30mg) depending on body weight, the severity of the disease, and the age of the children. For adults, doses are 450mg-2g.
For Intensive Care Unit Patients
It is further subdivided into two categories, where pseudomonas infection is not an issue and where pseudomonas infection is an issue.
Preferred choices of drugs for the treatment of patients in which pseudomonas infection is not an issue are respiratory fluoroquinolones plus macrolides or extended-spectrum cephalosporins plus ampicillin.
Preferred choices of drugs for the treatment of patients in which pseudomonas infection is an issue are anti-pneumococcal/antipseudomonal, piperacillin, tazobactam plus cefepime (4th generation cephalosporin). Cefepime is superior to ceftazidime and piperacillin for nosocomial isolates of Enterobacter, Citrobacter, and Serratia species.
In case of comorbidities where the patient is suffering from chronic heart, lung, liver, or renal disease, diabetes, alcoholism, or immunosuppressive conditions, preferred drugs are respiratory fluoroquinolones (gemifloxacin, levofloxacin, moxifloxacin) plus β-lactam (amoxicillin) plus macrolides.
Prevention Of Pneumonia
Pneumonia can be very serious and even life-threatening. So whenever possible take steps to prevent the infection.
Vaccination is an effective way to prevent pneumonia infection. Vaccines are biological preparations that increase or boost your immunity. Vaccines cannot prevent all cases of infections. But if a person is vaccinated, then he has a milder case of infection.
Commonly used vaccines for the prevention of pneumonia are Pneumococcal pneumonia vaccines. These vaccines are used against streptococcus pneumonia. There are two types of Pneumococcal Pneumonia Vaccines, the Polysaccharide Vaccine, and the Conjugated Vaccine
Other vaccines used for the prevention of pneumonia are the Influenza vaccine and HIB (Haemophilus influenzea type b).
Besides vaccination, you must follow the following preventive measures,
- Hand washing
- Good hygiene practices to prevent pneumonia
- Medical devices and respiratory equipment should be cleaned and disinfected
- Things used by an infected person should be washed and disinfected before normal use
- Avoid contact with infected people
- Don't smoke: Smoking increases the risk of pneumonia
- Make the immune system strong: Immune system can be made strong through a proper diet (i.e. fruits, vegetables, fresh juices, etc.) and physical activity