22nd July, 2014
By Bilikis Bakare
Globally, pneumonia kills more than 1 million children younger than 5 years of age each year. This is found to be greater than the number of deaths from any infectious diseases such as HIV infection, malaria or tuberculosis. Pneumonia is an infection of the lungs that causes mild and severe illness in people of all ages, but usually in adults 65 years of age or older and children younger than 5 years of age. Other group of people referred to as high risk sufferers include, those with diabetes or heart disease, asthmatics and those who smoke cigarettes.
The lungs are located in the chest, one on either side of the chest. The one on the right is divided into 3 sections referred to as lobes, while that of the left is divided into 2 lobes. Each lung is conical in shape and is pinkish white in colour at birth; in adult life the colour is dark grey, mottled in patches and it gets darker as one advances in age. They are soft and protected by the ribcage. The main functions of the lungs are to bring oxygen- gas that provides energy- in to the body and to remove carbon dioxide, which is a waste product or exhaust of the body.
Normally, the lungs have mechanisms of protecting themselves from irritants that can cause damage to the body. Firstly, the nose acts as a filter when breathing in, preventing large particles of pollutants from entering the lungs. But if an irritant does enter the lungs, it will get stuck in a thin layer of mucus that lines the inside of the respiratory tract, producing sputum or phlegm. An average of 3 ounces of sputum is secreted onto the lining of these breathing tubes every day. The mucus, sputum or phlegm is swept up towards the mouth by little hairs called cilia that line the breathing tubes. Cilia move mucus from the lungs upward towards the throat to the epiglottis- the gate which opens allowing the mucus to be swallowed. Another way through which the lungs protect themselves is by coughing up any irritant that enters the body through the nose.
The process takes place every day without an individual even thinking about it. Therefore, spitting up is not normal and does not occur unless the individual has chronic bronchitis or an infection such as chest, cold or pneumonia.
Pneumonia can be caused by a virus, bacteria or fungi. Common causes of viral pneumonia are influenza and respiratory syncytial virus (RSV), and a common cause of bacterial pneumonia is Streptococcus pneumoniae (pneumococcus). In children younger than 1 year of age, RSV is the most common cause of pneumonia. It can be classified according to the environment in which it is contracted. When someone develops pneumonia in the community (not in a hospital), it’s called community-acquired pneumonia (CAP). Pneumonia developed during or following a stay in a healthcare facility (like hospitals, long-term care facilities and dialysis centres) is called health care associated pneumonia (HCAP) which includes hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP).
Ventilator- associated pneumonia (VAP) is detected by using a combination of radiological, clinical, and laboratory criteria. VAP is suspected when a patient receiving mechanical ventilation has evidence of a new or progressive pulmonary infiltrate along with fever, leukocytosis, and purulent trachea-bronchial secretions. Pneumonia is considered ventilator associated if the patient was intubated and receiving mechanical ventilation at the time of or within 48 hours before the onset of infection.
According to experts, placement of an endotracheal tube can potentially increase the risk of VAP 6- to 20-fold in patients treated with mechanical ventilation. For VAP to develop, microorganisms must gain access to the normally sterile lower part of the respiratory tract. Critically ill patients are at risk for microorganisms getting into the lower part of the tract because these patients have a depressed level of consciousness and an impaired gag reflex, which may lead to pooling of approximately 100 to 150 ml of contaminated secretions within the oropharynx within a 24-hour period. Placement of an endotracheal tube impedes the body’s natural defence against infection by negating effective cough reflexes and mucocilliary clearance of secretions. Impairment of the cough reflex, accumulation of contaminated secretions within the oropharynx, and placement of an endotracheal tube substantially increase the risk for VAP in critically ill patients.
Health care-associated pneumonia is a relatively new classification of pneumonia that includes community-dwelling pneumonia patients having contact with the health care system. Current data indicate that health care-associated pneumonia patients present with more severe disease, are more likely to be infected with drug-resistant pathogens, and suffer increased mortality compared with community-acquired pneumonia patients. Guidelines recommend that these patients receive empiric antibiotics similar to those recommended for nosocomial pneumonia; however, it is not currently known if outcomes are improved when health care-associated pneumonia patients are treated in the same way as the community acquired ones.
Most common symptoms of pneumonia include high fever, chills, cough with phlegm that does not improve or get worse, shortness of breath with normal daily activities and chest pain when breathing. Basic personal and environmental hygiene is essential in the prevention of pneumonia. This includes regular washing of hands, cleaning hard surfaces that are touched often (like doorknobs and countertops), and coughing or sneezing into a tissue or into your elbow or sleeve. The risk of getting pneumonia can also be reduced by limiting exposure to cigarette smoke and prompt treatment and prevention of conditions like diabetes and asthma. Those with certain health conditions, like diabetes and asthma, should be encouraged to get vaccinated against the flu and bacterial pneumonia.
There are several vaccines that prevent infection by bacteria or viruses that may cause pneumonia. These vaccines include pneumococcal, Haemophilus influenza type b, pertussis (whooping cough), varicella (chickenpox), measles and influenza (flu).
Provision and access to vaccines and treatment (like antibiotics and antivirals) by the various tiers of governments can help prevent many pneumonia-related deaths. The public should be sensitized to reduce indoor air pollution and encouraged to imbibe good hygiene practices. Smoking should be discouraged, especially in public places to reduce the risk of contracting pneumonia through side stream smoking.
•Bakare wrote from Alausa, Ikeja.