Lower respiratory tract infection | |
---|---|
Conducting passages | |
Specialty | Pulmonology |
Frequency | 291 million (2015) [1] |
Deaths | 2.74 million (2015) [2] |
Lower respiratory tract infection (LRTI) is a term often used as a synonym for pneumonia but can also be applied to other types of infection including lung abscess and acute bronchitis. Symptoms include shortness of breath, weakness, fever, coughing and fatigue. [3] A routine chest X-ray is not always necessary for people who have symptoms of a lower respiratory tract infection. [4]
Influenza affects both the upper and lower respiratory tracts.[ citation needed ]
Antibiotics are the first line treatment for pneumonia; however, they are neither effective nor indicated for parasitic or viral infections. Acute bronchitis typically resolves on its own with time.[ citation needed ]
In 2015 there were about 291 million cases. [1] These resulted in 2.74 million deaths down from 3.4 million deaths in 1990. [5] [2] This was 4.8% of all deaths in 2013. [5]
Bronchitis describes the swelling or inflammation of the [6] bronchial tubes. Additionally, bronchitis is described as either acute or chronic depending on its presentation and is also further described by the causative agent. Acute bronchitis can be defined as acute bacterial or viral infection of the larger airways in healthy patients with no history of recurrent disease. [7] It affects over 40 adults per 1000 each year and consists of transient inflammation of the major bronchi and trachea. [8] Most often it is caused by viral infection and hence antibiotic therapy is not indicated in immunocompetent individuals. [9] [6] Viral bronchitis can sometimes be treated using antiviral medications depending on the virus causing the infection, and medications such as anti-inflammatory drugs and expectorants can help mitigate the symptoms. [10] [6] Treatment of acute bronchitis with antibiotics is common but controversial as their use has only moderate benefit weighted against potential side effects (nausea and vomiting), increased resistance, and cost of treatment in a self-limiting condition. [8] [11] Beta2 agonists are sometimes used to relieve the cough associated with acute bronchitis. In a recent systematic review it was found there was no evidence to support their use. [6]
Acute exacerbations of chronic bronchitis (AECB) are frequently due to non-infective causes along with viral ones. 50% of patients are colonised with Haemophilus influenzae, Streptococcus pneumoniae, or Moraxella catarrhalis. [7] Antibiotics have only been shown to be effective if all three of the following symptoms are present: increased dyspnea, increased sputum volume, and purulence. In these cases, 500 mg of amoxicillin orally, every 8 hours for 5 days or 100 mg doxycycline orally for 5 days should be used. [7]
Pneumonia occurs in a variety of situations and treatment must vary according to the situation. [10] It is classified as either community or hospital acquired depending on where the patient contracted the infection. It is life-threatening in the elderly or those who are immunocompromised. [12] [13] The most common treatment is antibiotics and these vary in their adverse effects and their effectiveness. [12] [14] Pneumonia is also the leading cause of death in children less than five years of age in low income countries. [14] The most common cause of pneumonia is pneumococcal bacteria, Streptococcus pneumoniae accounts for 2/3 of bacteremic pneumonias. [15] Invasive pneumococcal pneumonia has a mortality rate of around 20%. [13] For optimal management of a pneumonia patient, the following must be assessed: pneumonia severity (including treatment location, e.g., home, hospital or intensive care), identification of causative organism, analgesia of chest pain, the need for supplemental oxygen, physiotherapy, hydration, bronchodilators and possible complications of emphysema or lung abscess. [16]
Typical bacterial Infections:
Atypical bacterial Infections:
Vaccination helps prevent bronchopneumonia, mostly against influenza viruses, adenoviruses, measles, rubella, streptococcus pneumoniae, haemophilus influenzae, diphtheria, bacillus anthracis, chickenpox, and bordetella pertussis. [18] Specifically for the children with low serum retinol or who are suffering from malnutrition, vitamin A supplements are recommended as a preventive measure against acute LRTI. [19]
Antibiotics do not help the many lower respiratory infections which are caused by parasites or viruses. While acute bronchitis often does not require antibiotic therapy, antibiotics can be given to patients with acute exacerbations of chronic bronchitis. [20] The indications for treatment are increased dyspnoea, and an increase in the volume or purulence of the sputum. [21] The treatment of bacterial pneumonia is selected by considering the age of the patient, the severity of the illness and the presence of underlying disease. A systematic review of 32 randomised controlled trials with 6,078 participants with acute respiratory infections compared procalcitonin (a blood marker for bacterial infections) to guide the initiation and duration of antibiotic treatment, against no use of procalcitonin. Among 3,336 people receiving procalcitonin-guided antibiotic therapy, there were 236 deaths, compared to 336 deaths out 3,372 participants who did not. Procalcitonin-guided antibiotic therapy also reduced the antibiotic use duration by 2.4 days, and there were fewer antibiotic side effects. This means that procalcitonin is useful for guiding whether to use antibiotics for acute respiratory infections and the duration of the antibiotic. [22] Amoxicillin and doxycycline are suitable for many of the lower respiratory tract infections seen in general practice. [20] Another cochrane review suggests that new studies are needed to confirm that azithromycin may lead to less treatment failure and lower side effects than amoxycillin. [23] In the other hand, there is no sufficient evidence to consider the antibiotics as a prophylaxis for the high risk children under 12 years. [24]
Oxygen supplementation is often recommended for people with severe lower respiratory tract infections. [25] Oxygen can be provided in a non-invasive manner using nasal prongs, face masks, a head box or hood, a nasal catheter, or a nasopharyngeal catheter. [25] For children younger than 15 years old, nasopharyngel catheters or nasal prongs are recommended over a face mask or head box. [25] A Cochrane review in 2014 presented a summary to identify children complaining of severe LRTI, however; further research is required to determine the effectiveness of supplemental oxygen and the best delivery method. [25]
Lower respiratory infectious disease is the fifth-leading cause of death and the combined leading infectious cause of death, being responsible for 2.74 million deaths worldwide. [26] This is generally similar to estimates in the 2010 Global Burden of Disease study. [27] This total only accounts for Streptococcus pneumoniae and Haemophilus influenzae infections and does not account for atypical or nosocomial causes of lower respiratory disease, therefore underestimating total disease burden.[ citation needed ]
Lower respiratory tract infections place a considerable strain on the health budget and are generally more serious than upper respiratory infections.[ citation needed ]
Workplace burdens arise from the acquisition of a lower respiratory tract infection, with factors such as total per person expenditures and total medical service utilisation demonstrated as greater among individuals experiencing a lower respiratory tract infection. [28]
Pan-national data collection indicates that childhood nutrition plays a significant role in determining the acquisition of a lower respiratory tract infection, with the promotion of the implementation of nutrition program, and policy guidelines in affected countries. [26]
Sinusitis, also known as rhinosinusitis, is an inflammation of the mucous membranes that line the sinuses resulting in symptoms that may include thick nasal mucus, a plugged nose, and facial pain.
Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, coughing, chest tightness, and shortness of breath. These may occur a few times a day or a few times per week. Depending on the person, asthma symptoms may become worse at night or with exercise.
Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severity of the condition is variable.
The common cold or the cold is a viral infectious disease of the upper respiratory tract that primarily affects the respiratory mucosa of the nose, throat, sinuses, and larynx. Signs and symptoms may appear fewer than two days after exposure to the virus. These may include coughing, sore throat, runny nose, sneezing, headache, and fever. People usually recover in seven to ten days, but some symptoms may last up to three weeks. Occasionally, those with other health problems may develop pneumonia.
A cough is a sudden expulsion of air through the large breathing passages which can help clear them of fluids, irritants, foreign particles and microbes. As a protective reflex, coughing can be repetitive with the cough reflex following three phases: an inhalation, a forced exhalation against a closed glottis, and a violent release of air from the lungs following opening of the glottis, usually accompanied by a distinctive sound.
Otitis media is a group of inflammatory diseases of the middle ear. One of the two main types is acute otitis media (AOM), an infection of rapid onset that usually presents with ear pain. In young children this may result in pulling at the ear, increased crying, and poor sleep. Decreased eating and a fever may also be present. The other main type is otitis media with effusion (OME), typically not associated with symptoms, although occasionally a feeling of fullness is described; it is defined as the presence of non-infectious fluid in the middle ear which may persist for weeks or months often after an episode of acute otitis media. Chronic suppurative otitis media (CSOM) is middle ear inflammation that results in a perforated tympanic membrane with discharge from the ear for more than six weeks. It may be a complication of acute otitis media. Pain is rarely present. All three types of otitis media may be associated with hearing loss. If children with hearing loss due to OME do not learn sign language, it may affect their ability to learn.
Pharyngitis is inflammation of the back of the throat, known as the pharynx. It typically results in a sore throat and fever. Other symptoms may include a runny nose, cough, headache, difficulty swallowing, swollen lymph nodes, and a hoarse voice. Symptoms usually last 3–5 days, but can be longer depending on cause. Complications can include sinusitis and acute otitis media. Pharyngitis is a type of upper respiratory tract infection.
Acute bronchitis, also known as a chest cold, is short-term bronchitis – inflammation of the bronchi of the lungs. The most common symptom is a cough. Other symptoms include coughing up mucus, wheezing, shortness of breath, fever, and chest discomfort. The infection may last from a few to ten days. The cough may persist for several weeks afterward with the total duration of symptoms usually around three weeks. Some have symptoms for up to six weeks.
Bronchiolitis is inflammation of the small airways in the lungs. Acute bronchiolitis is due to a viral infection usually affecting children younger than two years of age. Symptoms may include fever, cough, runny nose, wheezing, and breathing problems. More severe cases may be associated with nasal flaring, grunting, or the skin between the ribs pulling in with breathing. If the child has not been able to feed properly, signs of dehydration may be present.
Respiratory syncytial virus (RSV), also called human respiratory syncytial virus (hRSV) and human orthopneumovirus, is a contagious virus that causes infections of the respiratory tract. It is a negative-sense, single-stranded RNA virus. Its name is derived from the large cells known as syncytia that form when infected cells fuse.
Klebsiella pneumoniae is a Gram-negative, non-motile, encapsulated, lactose-fermenting, facultative anaerobic, rod-shaped bacterium. It appears as a mucoid lactose fermenter on MacConkey agar.
An upper respiratory tract infection (URTI) is an illness caused by an acute infection, which involves the upper respiratory tract, including the nose, sinuses, pharynx, larynx or trachea. This commonly includes nasal obstruction, sore throat, tonsillitis, pharyngitis, laryngitis, sinusitis, otitis media, and the common cold. Most infections are viral in nature, and in other instances, the cause is bacterial. URTIs can also be fungal or helminthic in origin, but these are less common.
Procalcitonin (PCT) is a peptide precursor of the hormone calcitonin, the latter being involved with calcium homeostasis. It arises once preprocalcitonin is cleaved by endopeptidase. It was first identified by Leonard J. Deftos and Bernard A. Roos in the 1970s. It is composed of 116 amino acids and is produced by parafollicular cells of the thyroid and by the neuroendocrine cells of the lung and the intestine.
Ventilator-associated pneumonia (VAP) is a type of lung infection that occurs in people who are on mechanical ventilation breathing machines in hospitals. As such, VAP typically affects critically ill persons that are in an intensive care unit (ICU) and have been on a mechanical ventilator for at least 48 hours. VAP is a major source of increased illness and death. Persons with VAP have increased lengths of ICU hospitalization and have up to a 20–30% death rate. The diagnosis of VAP varies among hospitals and providers but usually requires a new infiltrate on chest x-ray plus two or more other factors. These factors include temperatures of >38 °C or <36 °C, a white blood cell count of >12 × 109/ml, purulent secretions from the airways in the lung, and/or reduction in gas exchange.
Respiratory tract infections (RTIs) are infectious diseases involving the lower or upper respiratory tract. An infection of this type usually is further classified as an upper respiratory tract infection or a lower respiratory tract infection. Lower respiratory infections, such as pneumonia, tend to be far more severe than upper respiratory infections, such as the common cold.
Hospital-acquired pneumonia (HAP) or nosocomial pneumonia refers to any pneumonia contracted by a patient in a hospital at least 48–72 hours after being admitted. It is thus distinguished from community-acquired pneumonia. It is usually caused by a bacterial infection, rather than a virus.
Bronchitis is inflammation of the bronchi in the lungs that causes coughing. Bronchitis usually begins as an infection in the nose, ears, throat, or sinuses. The infection then makes its way down to the bronchi. Symptoms include coughing up sputum, wheezing, shortness of breath, and chest pain. Bronchitis can be acute or chronic.
Meningitis is acute or chronic inflammation of the protective membranes covering the brain and spinal cord, collectively called the meninges. The most common symptoms are fever, intense headache, vomiting and neck stiffness and occasionally photophobia.
An acute exacerbation of chronic obstructive pulmonary disease, or acute exacerbations of chronic bronchitis (AECB), is a sudden worsening of chronic obstructive pulmonary disease (COPD) symptoms including shortness of breath, quantity and color of phlegm that typically lasts for several days.
Chronic obstructive pulmonary disease (COPD) is a type of progressive lung disease characterized by long-term respiratory symptoms and airflow limitation. GOLD 2024 defined COPD as a heterogeneous lung condition characterized by chronic respiratory symptoms due to abnormalities of the airways and/or alveoli (emphysema) that cause persistent, often progressive, airflow obstruction.
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