Pneumonia, an infection of the lungs, occurs when an illness causes an increase in mucus in the airways. The mucus allows viruses and bacteria to multiply, resulting in the infection. The American Academy of Family Physicians reports that viruses and the bacteria Streptococcus pneumoniae are the most common causes of pneumonia in infants and children. Symptoms of pneumonia include cough, fever, shortness of breath, chills, headache, sweating, fatigue and loss of appetite. Although doctors can treat most patients at home without hospitalization, some children develop complications that can be serious.
Bacteremia and Sepsis
MedlinePlus, a website sponsored by the National Institutes of Health, reports that pneumonia caused by bacteria results in the most serious infections. Bacteremia describes a condition that occurs when bacteria enters the bloodstream. The first signs of bacteremia include a fever, rapid heartbeat and rapid breathing. If left undetected, the toxins produced by the bacteria in the blood build up and trigger the immune system to release cytokines that cause inflammation. This condition is known as sepsis--a serious complete-body response to the bacteremia.
Sepsis causes an abnormally high fever and can lead to a decrease in blood pressure. As the blood pressure decreases, the heart works harder, increasing the heart rate. Eventually the heart weakens from the added stress and less blood pumps out to the organs, leading to organ malfunction. The Merck Manual reports that death caused by sepsis occurs in about 15 percent of patients.
Lung Abscess
A bacterial infection of the lungs can cause the formation of a lung abscess--a pus-filled cavity in the lungs. The fluid inside a lung abscess puts pressure on the lungs, which can affect lung function. Symptoms of a lung abscess, also known as empyema, include chest pain, dry cough, excessive sweating, fever, shortness of breath and unexplained weight loss. As a complication of pneumonia, treatment includes not only curing the infection, but also draining the pus from the lung. The presence of a lung abscess increases the risk of permanent lung damage and death from the pneumonia.
Acute Respiratory Distress Syndrome
Acute respiratory distress syndrome, a life-threatening condition, leads to low oxygen levels in the blood. Normally, air enters the lungs through the bronchi and travels through the bronchial tubes to the tiny air sacs known as alveoli. Capillaries surround the alveoli, allowing for the exchange of fluids, oxygen and carbon dioxide between the lungs and the blood. A lung infection interferes with the intake of air and causes too much fluid to leak from the capillaries into the air sacs. This interferes with the exchange of oxygen, resulting in too little oxygen in the blood.
Patients in acute respiratory distress feel as though they cannot get enough air. The low blood oxygen level causes severe fatigue. When the organs, such as the heart and kidneys, fail to receive enough oxygen, they begin to malfunction. This can lead to low blood pressure and confusion. Acute respiratory distress syndrome requires hospitalization for treatment and can lead to further complications such as lung scarring.
