PNEUMONIA


pneumonia can be defined as an acute inflammation (respiratory illness) of the lung (alveoli sac) that can lead to fluid accumulation in the lung. Pneumonia can arise as a complication of several diseases such as Corona virus.


Statistics:

 According to statistics, It is said that over 450 million people suffer from pneumonia with over 2.56 million recorded death from pneumonia in 2017.

Pneumonia in Children: 

One third of pneumonia cases were children below 5 years of age and it is important to know that pneumonia is the leading cause of death in children of this age group (below 5 years). According to the world health organization (WHO), in the year 2017, we recorded a total of 808694 pneumonia  death in children.

Mortality rate of Pneumonia: 

The mortality rate of pneumonia is between 5 to 10% in Hospitalized patients and can drastically increase to greater than 30% for patients in the intensive care unit. In the year 2017, we recorded 2.56 million death from pneumonia worldwide. 

Areas with highest incidence for pneumonia: 

pneumonia is highest in developing countries with South Asia and sub Saharan Africa having the highest number of pneumonia cases. In the year 2015, India was the country with the highest number of pneumonia cases

In the United States, pneumonia accounts for over 3 million cases every year. 


Categorization of Pneumonia

Pneumonia can be categorized into 3;

  • Segmental
  • Lobal
  • Multilobal


Lobal pneumonia:

 can be used as a pathological as well as a radiologic term to describe a homogeneous (uniform) consolidation of one or more than one lobe, characterized with pleural effusion. If we have more than a single love, then such pneumonia is described as multilobal. 


Bronchial pneumonia:

describes a patchy alveoli with consolidation associated with bronchial or bronchiolar inflammation. It is often bilateral. 


Causes of Pneumonia

Pneumonia is an acute respiratory disease that's mostly caused by viruses, bacteria and fungi. Majority of upper respiratory tract infections might be due to virus but the major cause of pneumonia in all age groups is streptococcus pneumoniae. The symptoms of pneumonia will depend on what kind of pneumonia you have. 


Mode of Transmission of Pneumonia

Pneumonia is greatly contagious and the treatment is based on preventing the multiplication of the bacteria. The major cause of pneumonia is strep. Pneumoniae. If proper antibiotics are given to patients suffering from pneumonia, they seize to be contagious within 2 to 3 days. The method of spread of pneumonia is via respiratory droppler during sneezing, coughing, talking etc. 


Staging of Pneumonia

Staging of pneumonia is done for patients having lobal pneumonia. This is a characteristic of how lobar pneumonia progresses if left untreated. There are four major stages of lobar pneumonia:

  1.  Congestion: the process of congestion occurs within 24 hours after infection. During congestion, the capillary vessels in the alveoli wall become congested with the presence of intravascular fluid as a result. Patients will often present with multiple bacteria present in the lung. 
  2. Red Hepatization: this stage proceeds after the congestion stage and is ofen after 2 - 3 days after congestion has occurred. Frome the name, it signifies the appearance of the liver cells. The liver cells will present red in color. The alveoli of the lungs will present with massive RBCs, Neutrophils, desquamated epithelial cells and fibrin. 
  3. Grey Hepatization: this stage occurs 2 - 3 days after Red Hepatization. Patient presents with a greyish-brown liver color due to distergration of liver cells. Also, patient will have a dry lung
  4. Resolution (complete recovery): this process of complete recovery occurs after Grey Hepatization when exudate have experienced a progressive enzymatic digestion.


Types of Pneumonia

Pneumonia can be described in a greater detail under 2 major types. Pneumonia can be community acquired or hospital acquired. In this article, we will focus lot more on community acquired pneumonia as it is the most commonly seen in our hospitals. The clinical features of pneumonia, differential diagnosis of pneumonia and it's management will also be discussed on in greater detail.  


Community Acquired Pneumonia (CAP)

Community acquired pneumonia affects mostly the very old and very young. 

The mode of Transmission of community acquired pneumonia is via respiratory dropplets. 


Causes of Community Acquired Pneumonia (CAP)

  • The major cause of pneumonia is streptococcus pneumoniae (affecting individuals of all age groups)
  • Mycoplasma pneumonia (children and young adults)
  • Legionella pneumophila (middle to old age)
  • Chlamydia pneumoniae ( young to middle age)
  • Haemophilia influenzae (common in old age and in children with underlying lung disease (COPD, Bronchiectasis)

Primary viral pneumonias 

  • Influenza and parainfluenza (Pneumonia in patients with secondary bacterial infections)
  • Measles
  • Herpes simplex (Pneumonia in immunosuopressed)
  • Varicella zuster (severe Pneumonia)
  • Adenovirus (pneumonia inalnourished children or immunosuppressed)
  • Corona virus (severe acute respiratory distress disease) 


Symptoms of Pneumonia

Systemic symptoms of Pneumonia

  • Fever
  • Chills
  • Rigor
  • Shievering 
  • Vomiting
  • Loss of appetite 
  • Head ache

Pulmonary symptoms

  • Dyspnoea (difficulties in breathing)
  • Cough (will be short, painful and dry but as it progresses will later be accompanied by expectoration of mucopurulent sputum)
  • Rust coloured sputum (an indication for streptococcus pneumoniae)
  • Chest pain radiating to shoulder or anterior abdominal wall
  • Wheezing
  • Upper abdominal tenderness( lower lobe Pneumonia, characteristic of hepatitis infection) 
  • Consolidation (due to accumulation of infected cells in the alveoli sac)


Risk Factors

The risk factors associated with pneumonia infection include:

  • Cigarette smoking
  • Upper Respiratory Tract Infection (URTI)
  • Alcohol
  • Corticosteroids
  • Old age (65>)
  • Recent influenza infection 
  • Pre-existing lung disease 
  • HIV
  • Air pollution


Differential Diagnosis of Pneumonia

1. Pulmonary infarction
2. Pulmonary/pleural TB
3. Pulmonary Oedema (can be unilateral in some cases)
4. Pulmonary Eusinophilia
5. Malignancy (bronchoalveolar cell carcinoma)


Laboratory Investigation

The main objective of a laboratory investigation is to exclude the differential diagnosis associated with Pneumonia-like symptoms, to assess the severity of Pneumonia and lastly to identify the development of complications associated with pneumonia infections. The investigations to be carried out include: 

  1. Chest x-ray (an opaque localization can be a sign of lobar pneumonia. Opaque nature appears within 12 to 18 hours after infection by microorganism)

All patients should have the following laboratory investigations

  • Sputum
  • Blood culture 
  • Serology
  • PCR

Investigatio for Severe patient 

The following test are subjective in patients presenting with severe pneumonia in addition to the above mentioned laboratory investigations 

  1. Tracheal aspirate
  2. Throat swap
  3. Eural fluid
  4. Cold agglutinine


Managent of Community Acquired Pneumonia

The management of pneumonia can be done without identification of the causative agent in patients with acute pneumonia. Acute pneumonia is also referred to as walking pneumonia since the patient will be able to do his normal day to day activities. The management of walking Pneumonia is subjective to patients and include

  • Oxygenation:

 very important especially for patients with an oxygen partial pressure <60mmHg or PaO2 <8kPa or SaO2 > 92%.


IV fluid: 

 this is very important for patients with severe illness, older patients and also for patients vomiting. If patient do not fit these 3 conditions, it is advisable to encourage patient to increase their level of fluid intake. 


Conditions for Hospitalization due to pneumonia

The CURB-65 scale is used to assess patients severity of illness and to guide the decision of the healthcare provider on wether or not patient should be hospitalized. Every letter in the CURB-65 SCALE is very important. The method of assessment is given thus: a score of 1 is given to patients that fit each criteria and the cumulative used to make the decision

C = Confusion

U = Urea > 7mmol/l

R = respiratory rate > 30/min

B = systole < 90mmHg or diastole <60mmHg

65 = patients with age 65 and above are also given a score 

Evaluation of CURB-65 score

0 - 1 = Suitable for home treatment

2 = Hospital Supervised Treatment

3 or more = managed as severe pneumonia


Treatment

The treatment option for Community Acquired Pneumonia involves the giving of antibiotics and also to focus on other underlying causes or complications. Care should be taken when prescribing antibiotics to prevent antibiotic resistance and allergic reactions.

  •  The drug of choice for the treatment of pneumonia include a joint those of amoxicillin + clavulanic acid. 

  • Patients suffering from pleural effusion can be given paracetamol, co-codamol or NSAIDs
  • Opiods should be used with precautions in the treatment of pleural pain as patient will need ventilation especially for patients with poor Respiratory function rate. 
  • Physiotherapy have been proven to be helpful in the management of patients having expectorations and suppress cough because of pleural pain or bronchial collapse because of mucus plug