Pneumonia

Posted by Pozziepinoy on 8:53 AM

I would like to discuss this topic because not only it is an opportunistic infection (OI) especially if it recurs within a year, but also one poz is now confined because of it. Yesterday he texted me and told me that he was in a bad condition. He said that he has difficulty in breathing and he can hardly walk. He also has high grade fever. He was thinking he has a lung problem. I told him to get himself checked by a doctor (in that case, a lung specialist). The following afternoon, he told me that his pulmo doctor said that he has pneumonia and he needs to be confined. I told him to do what the doctor tells him to do no matter what.

To all my readers, please help pray for him so that he can recover fast and regain his life back.


Please, if you have the symptoms being discussed here, don't think twice. Go and seek consult immediately. Go to a pulmo doctor fast! If you need a good pulmonologist, I know one. Just email me at pozziepinoy@yahoo.com.


Pneumonia can be cured if treated fast!





WHAT IS PNEUMONIA?

Pneumonia is an infection of one or both lungs which is usually caused by bacteria, viruses, or fungi. Prior to the discovery of antibiotics, one-third of all people who developed pneumonia subsequently died from the infection. Currently, over 3 million people develop pneumonia each year in the United States. Over a half a million of these people are admitted to a hospital for treatment. Although most of these people recover, approximately 5% will die from pneumonia. Pneumonia is the sixth leading cause of death in the United States.


HOW DO PEOPLE "CATCH" PNEUMONIA?

Some cases of pneumonia are contracted by breathing in small droplets that contain the organisms that can cause pneumonia. These droplets get into the air when a person infected with these germs coughs or sneezes. In other cases, pneumonia is caused when bacteria or viruses that are normally present in the mouth, throat, or nose inadvertently enter the lung. During sleep, it is quite common for people to aspirate secretions from the mouth, throat, or nose. Normally, the body's reflex response (coughing back up the secretions) and their immune system will prevent the aspirated organisms from causing pneumonia. 
However, if a person is in a weakened condition from another illness, a severe pneumonia can develop. People with recent viral infections, lung disease, heart disease, and  swallowing problems , as well as alcoholics, drug users, and those who have suffered a stroke or seizure are at higher risk for developing pneumonia than the general population. As we age, our swallowing mechanism can become impaired as does our immune system. These factors, along with some of the negative side effects of medications, increase the risk for pneumonia in the elderly.

Once organisms enter the lungs, they usually settle in the air sacs and passages of the lung where they rapidly grow in number. This area of the lung then becomes filled with fluid and pus (the body's inflammatory cells) as the body attempts to fight off the infection.



WHAT ARE THE SIGNS AND SYMPTOMS OF PNEUMONIA?

Most people who develop pneumonia initially have symptoms of a cold ( upper respiratory infection , for example, sneezing, sore throat, cough), which are then followed by a high fever (sometimes as high as 104 F), shaking chills, and a cough with sputum production. The sputum is usually discolored and sometimes bloody. Depending on the location of the infection, certain symptoms are more likely to develop. When the infection settles in the air passages, cough and sputum tend to predominate the symptoms. In some, the spongy tissue of the lungs that contain the air sacs is more involved. In this case, oxygenation of the blood can be impaired, along with stiffening of the lung, which results in shortness of breath. At times, the individual's skin color may change and become dusky or purplish (a condition known as "cyanosis") due to their blood being poorly oxygenated.

The only pain fibers in the lung are on the surface of the lung, in the area known as the pleura. Chest pain may develop if the outer aspects of the lung close to the pleura are involved in the infection. This pain is usually sharp and worsens when taking a deep breath and is known as pleuritic pain or pleurisy. In other cases of pneumonia, depending on the causative organism, there can be a slow onset of symptoms. A worsening cough, headaches, and muscle aches may be the only symptoms.

Children and babies who develop pneumonia often do not have any specific signs of a chest infection but develop a fever, appear quite ill, and can become lethargic. Elderly people may also have few symptoms with pneumonia.


HOW IS PNEUMONIA DIAGNOSED?

Pneumonia may be suspected when the doctor examines the patient and hears coarse breathing or crackling sounds when listening to a portion of the chest with a stethoscope. There may be wheezing or the sounds of breathing may be faint in a particular area of the chest. A chest X-ray is usually ordered to confirm the diagnosis of pneumonia. The lungs have several segments referred to as lobes, usually two on the left and three on the right. When the pneumonia affects one of these lobes, it is often referred to as lobar pneumonia. Some pneumonias have a more patchy distribution that does not involve specific lobes. In the past, when both lungs were involved in the infection, the term "double pneumonia" was used. This term is rarely used today.

Sputum samples can be collected and examined under the microscope. Pneumonia caused by bacteria or fungi can be detected by this examination. A sample of the sputum can be grown in special incubators, and the offending organism can be subsequently identified. It is important to understand that the sputum specimen must contain little saliva from the mouth and be delivered to the laboratory fairly quickly. Otherwise, overgrowth of noninfecting bacteria from the mouth may predominate. As we have used antibiotics in a broader uncontrolled fashion, more organisms are becoming resistant to the commonly used antibiotics. These types of cultures can help in directing more appropriate therapy.

A blood test that measures white blood cell count (WBC) may be performed. An individual's white blood cell count can often give a hint as to the severity of the pneumonia and whether it is caused by bacteria or a virus. An increased number of neutrophils, one type of WBC, is seen in most bacterial infections, whereas an increase in lymphocytes, another type of WBC, is seen in viral infections, fungal infections, and some bacterial infections (like tuberculosis).

A bronchoscopy is a procedure in which a thin, flexible, lighted viewing tube is inserted into the nose or mouth after a local anesthetic is administered. Using this device, the doctor can directly examine the breathing passages (trachea and bronchi). Simultaneously, samples of sputum or tissue from the infected part of the lung can be obtained.

Sometimes, fluid collects in the pleural space around the lung as a result of the inflammation from pneumonia. This fluid is called a pleural effusion. If a significant amount of fluid develops, it can be removed. After numbing the skin with local anesthetic a needle is inserted into the chest cavity and fluid can be withdrawn and examined under the microscope. This procedure is called a thoracentesis. Often ultrasound is used to prevent complications from this procedure. In some cases, this fluid can become severely inflamed (parapneumonic effusion) or infected (empyema) and may need to be removed by more aggressive surgical procedures. Today, most often, this involves surgery through a tube or thoracoscope. This is referred to as video-assisted thoracoscopic surgery or VATS.


PNEUMONIA AND HIV

Pneumonia in the immunocompromised host involves infection and inflammation of the lower respiratory tract. Regardless of the reason for altered immune function, pneumonia carries a high mortality rate in immunocompromised patients. 
Immunocompromise, and, consequently, a high risk of pneumonia, is associated with the presence of the following factors:
  • Malignancy
  • Human immunodeficiency virus (HIV) infection
  • Primary immunodeficiencies
  • Transplant immunosuppression
  • Pregnancy
  • Alcoholism
  • Cystic fibrosis
  • Autoimmune disease
  • Neuromuscular disease
  • Cognitive dysfunction
  • Spinal cord injury
  • Burns
  • Leukemia
  • Lymphoma
  • Extreme old or young age
  • Solid organ malignancy chemotherapy
  • Chronic steroids
  • Asplenia
  • Diabetes
Complications

Complications of pneumonia in immunocompromised persons can include the following:
  • Pneumothorax
  • Hypoglycemia (may occur with pentamidine)
  • Respiratory failure/ventilatory dependence
  • Acute respiratory distress syndrome
  • Superinfection
  • Pleural effusion
  • Empyema
  • Death
Causes of Pneumonia

Many pulmonary pathogens reliably plague a host who has a dysfunctional immune system. Others are encountered more frequently with certain causes of immune suppression. Therefore, the pathophysiology can be appreciated in general and more specific contexts.

Conceptually, pneumonia susceptibility due to immunosuppression stems from neutrophil defects, immunoglobulin defects, or T-cell defects. The underlying reason for immune suppression may suggest certain pulmonary pathology.

The etiologic agents responsible for pneumonias in immunocompromised patients are often different from those found in immunocompetent patients.

Infectious causes of pneumonia in immunocompromised patients include the following:
  • Bacterial organisms
  • Coccidioides species
  • Cytomegalovirus (CMV)
  • Tuberculosis (TB)
  • Histoplasma species
  • Aspergillus species
  • Mycobacterium avium complex (MAC)
  • Pneumocystis (carinii) jiroveci (PCP)
  • Influenza
  • Herpes simplex virus (HSV)
  • Varicella-zoster virus (VZV)
  • Legionella species
  • Nocardia species
  • Cryptococcus neoformans
  • Mucoraceae species
  • Strongyloides species
  • Toxoplasma species
  • Capnocytophaga species
Noninfectious causes of pneumonia in immunocompromised patients include the following:
  • Pulmonary hemorrhage
  • Pneumonitis
  • Congestive heart failure
  • Pulmonary embolism
  • Myocardial infarction
  • Pneumothorax
  • Drug-induced injury
  • Radiation-induced injury
Patients with human immunodeficiency virus (HIV) are at risk for a number of pulmonary infections. Pneumocystis jiroveci remains the most common opportunistic infection in this group; however, the epidemiology of pulmonary infections among patients with HIV is changing.

HIV causes dysfunction of cell-mediated, as well as humoral, immunity. CD4 T cells principally help other cells achieve their effector function. As such, at low CD4 levels, a disruption of B-cell differentiation occurs. Impaired B-cell functions, particularly of memory cells, are postulated to account for increased risk of infection.[3] Even after the initiation of highly active antiretroviral therapy (HAART), patients with HIV have reduced marginal zone B-cell percentages.

Tuberculosis

HIV is considered to be the greatest risk factor for TB. Patients with HIV are more likely to develop active tuberculosis (TB) once infected, and they have a higher risk of death from TB. HIV is the most important recognized risk factor for progression from latent to active tuberculosis.

Bacterial pneumonia

The most common bacterial pathogen causing illness in patients with HIV isStreptococcus pneumoniae. Patients infected with this organism develop pneumonia more frequently than do their non-HIV–infected counterparts, and they have a more severe clinical course when they are infected.

Pneumocystis (carinii) jiroveci pneumonia (PCP)

Pneumocystis (carinii) jiroveci infection remains the most common opportunistic infection among patients with HIV; however, its epidemiology is changing. Adoption of HAART has resulted in lower frequency of this infection.

Transmission of and infection from P (carinii) jiroveci is incompletely understood. Traditionally, infection in a patient with HIV has been thought to represent the reactivation latent colonization. Now, however, some evidence exists that the epidemiology of this infection is defined on a more local geographic level. As molecular analysis of P (carinii) jiroveci improves, so will the understanding of the transmission and epidemiology of this opportunistic infection. 

Histoplasmosis

For the immunocompetent host, histoplasmosis is frequently asymptomatic. In the setting of HIV, this infection is much more common and frequently progresses to disseminated disease. Immunocompromised persons living in endemic areas are at increased risk of disease.

Spores of the mold phase are inhaled and cause a localized or patchy bronchopneumonia. CD4 lymphocytes normally activate macrophages to control the infection. In patients with HIV and low CD4 counts, the likelihood of developing pulmonary and disseminated histoplasmosis is increased.

Coccidiomycosis

Coccidiomycosis also can lead to pneumonia. This fungal infection is caused byCoccidioides immitis, an organism endemic to large parts of the southwestern United States.

Spores are inhaled and then ingested by pulmonary macrophages. Impaired cell-mediated immunity in persons with HIV accounts for an increased risk of infection in these patients. Life-threatening infections have been described in patients both with HIV and impaired cellular immunity.

Cryptococcus

Cryptococcal pneumonia is more severe in patients with HIV. Patients with pulmonary disease frequently progress to disseminated disease.

Most cases are the result of the reactivation of a latent infection. Recognition and treatment are important, because pulmonary cryptococcus is thought to herald the onset of disseminated disease.

Herpes simplex virus and varicella-zoster virus

The pathophysiology of HSV and VZV infections in the setting of HIV is not well understood. Varicella pneumonia is not a common infection in patients with HIV. Few cases have been reported; these have included primary and reactivation disease.

Mycobacterium avium complex

Mycobacterium avium complex (MAC) infection refers to infection with either of two nontuberculous mycobacterial species, either M avium or M intracellulare. These infections can occur in non-HIV–infected patients; however, MAC is much more frequently encountered in the setting of HIV.

This infection is thought to represent a recent acquisition of organisms rather than the reactivation of a latent infection.

Staging of HIV-associated pneumonia

A staging system specifically for predicting mortality in HIV-associated pneumonia has been described. This model was developed by using classification tree analysis, and it relies on 3 commonly available clinical variables: neurologic symptoms, respiratory rate more than 25, and serum creatinine level. However, this study has not been subsequently validated in the era of HAART.

Malignancy

Neutrophil defects, immunoglobulin defects, and T-cell defects are all seen in patients with cancer.
Underlying malignancy itself is a risk factor for subsequent infections, while leukopenia and lymphopenia are common adverse reactions to chemotherapy.

Primary immunodeficiencies

Patients with primary immunodeficiencies are challenged by a number of pulmonary infections. The spectrum of illnesses they face is largely determined by their underlying immune dysfunction: humoral deficiencies, cellular deficiencies, or combined deficiencies.

Patients with defects of humoral immunity are unable to create functional antibodies. Their complications are characterized by severe, recurrent upper and lower respiratory tract infections.

Cellular deficiencies are rare conditions that affect T-cell development and function. Dysfunction of T cells invariably has an impact on B-cell activity; therefore, most of these conditions manifest as combined deficiencies.

In combined deficiencies, T-cell and B-cell function is disturbed. These patients present not only with recurrent episodes of respiratory syncytial virus (RSV), HSV, VZV, influenza, and other viral respiratory infections, but also with chronic diarrhea and chronic mucocutaneous candidiasis.

Transplant immunosuppression

Solid-organ and bone-marrow transplant patients have a heightened risk of pulmonary infection. Timing since transplantation, use of immunosuppressive medications, and the type of transplant are all important in predicting these complications.

For solid-organ and bone-marrow transplant patients, the time since transplant is a major predictor of infectious complications. Induction regimens are used in the early posttransplant period, while maintenance therapies are later, long-term medication strategies.

In addition, the depth and duration of neutropenia are risk factors for infection in transplant patients. Risk factors for pulmonary nocardial disease reportedly include the receipt of high-dose steroids, CMV disease in the previous 6 months, and high median calcineurin inhibitor level.

A variety of antilymphoproliferative agents are used commonly in solid-organ transplantation patients, including cyclosporine, azathioprine, and tacrolimus. Additionally, monoclonal and polyclonal antibodies to hematopoietic antigens are increasingly being used. The full medication history should be available through the patient’s transplant coordinator.

Like solid-organ transplant patients, various antilymphoproliferative agents are used commonly in bone-marrow transplantation patients. Distinguishing between CMV, idiopathic pneumonia syndrome, and graft-versus-host disease is challenging.

PCP can occur even in patients who are on prophylactic treatment with trimethoprim-sulfamethoxazole.

Pregnancy

Pregnancy results in immunologic changes, including a decrease in helper-T-cell numbers, a reduction in the activity of natural killer cells, and a decrease in cell-mediated immune function, that predispose patients to infections. In addition, the elevated serum concentrations of progesterone and 17beta-estradiol observed in the latter half of pregnancy can stimulate the growth and maturation ofCoccidioides immitis.

Cardiopulmonary changes that occur as a part of normal pregnancy may result in a diminished capacity to compensate for the effects of respiratory disease.

Further, a reluctance to perform imaging studies in pregnant patients may lead to delayed detection of pneumonias.

The etiologic agent is not identified in approximately half of cases of community-acquired pneumonia in pregnancy. S pneumoniae and Haemophilus influenzae are the most frequently identified bacterial agents.

Alcohol consumption

Alcohol consumption affects systemic and pulmonary immune function. Current alcohol use is an independent risk factor for severe community-acquired pneumonia. Additionally, patients who are alcoholics are frequently also smokers. The negative effect of these risk factors for pulmonary infections are additive. Chronic alcohol drinkers also have decreased saliva production, an important component of mucosal defense.

Patients who are receiving treatment with corticosteroids for alcoholic hepatitis are at increased risk of developing Pneumocystis pneumonia.

Cystic fibrosis

Patients with cystic fibrosis experience progressive lung disease, which leads to respiratory insufficiency and failure.

In cystic fibrosis, abnormal chloride and sodium transport in the respiratory epithelium results in the development of thick, viscous secretions. Chronic airway obstruction leads to colonization by pathogenic bacteria, including Pseudomonas aeruginosa.

Autoimmune diseases

Patients with autoimmune diseases, either primary ones or those resulting from immunosuppressive therapies, are at higher risk of infectious pulmonary complications.

In systemic lupus erythematosus (SLE), distinguishing infection from an autoimmune flare is important. Treatment with steroids in the setting of infection could be deleterious. Susceptibility to infections derives from therapeutic and disease-related factors.

Complement deficiencies and elevated Fc gamma III and granulocyte-macrophage colony-stimulating factor (GM-CSF) levels may contribute to increased susceptibility to infection in patients with SLE. Deficiencies of functional mannose-binding lectin do not appear to be the reason for increased infection burden.

Low complement, the use of more than 20 mg prednisone daily, and the use of cyclophosphamide in patients with SLE were important risk factors in multivariate analyses.

Severe manifestations of disease are treated with immunosuppressive therapies.

In connective tissue diseases, the primary condition and the use of immunosuppressive medications place patients at increased risk. Of 5,411 cases reviewed, 29% of patients developed a serious infection; 24% died from this infection—most reported as bacteremia or pneumonia.

Neuromuscular disease

Poorly managed secretions and frequent aspiration are risk factors for pneumonitis and pneumonias. Reasons for a breakdown in this component of pulmonary defense can be functional, resulting in an overwhelmed immune system.

Pneumonia is a leading cause of death in persons with neuromuscular disease. Impairment of cough and swallowing mechanisms contributes to an increased risk of pneumonia. Gastroesophageal reflux is more common, persistent, and severe in patients with cerebral palsy. Kyphoscoliosis secondary to unequal muscle tone leads to restrictive lung function and predisposes to atelectasis.

Cognitive dysfunction

Drooling, feeding problems, and aspiration place patients with cognitive dysfunction at higher risk of pulmonary infections.

Spinal cord injury

Muscular weakness from spinal cord injury may contribute to a dysfunctional cough reflex.

Extremes of age

Older patients may complain of fewer symptoms than younger patients, making the diagnosis more challenging.

Children and infants at risk of RSV infection include those younger than 24 months with chronic lung disease who have required medical therapy within 6 months of RSV season onset, preterm infants born prior to 32 weeks’ gestation, preterm infants born at 32-35 weeks’ gestation with at least 2 additional risk factors, and those with hemodynamically significant heart disease.

Burn

Complications arise from direct lung injury and from indirect pulmonary effects (eg, decreased lung expansion secondary to circumferential burns).

Bacterial clearance is impaired in patients with inhalational injury. This can result from a variety of causes, including impaired cough, impaired mucociliary action, airway plugging, and impaired alveolar macrophage function.

Selective oral decontamination in burn patients has been advocated in some burn centers. Reduced oral carriage of organisms responsible for pulmonary infections is speculated to account for a lower frequency of pneumonias in these patients.

Leukemia

Leukemia itself (primarily chronic lymphocytic leukemia) is characterized by frequent infectious episodes. Patients who are undergoing chemotherapy are additionally at risk for severe neutropenia and subsequent pulmonary infections.

Lymphoma

When lymphoma compromises airway lumen, secondary postobstructive pneumonias can develop. Patients with lymphoma are often taking steroids, which increase their risk of pulmonary infections.

Solid-organ malignancy chemotherapy

Patients who are undergoing chemotherapy for solid-organ tumors are at increased risk of infections. Pulmonary infections are common.

Steroids

Patients who are taking steroids long term are at higher risk for pulmonary infections.This includes patients who are taking steroids long term for sarcoidosis; they have the same risk for pulmonary infections as do other chronic steroid users, and they are also at risk for complications from postobstructive infections secondary to compressive granulomas.

The dose and duration of use are predictive of increased risk of pneumonia. Low-dose and short-term use carry minimal additional risk of pneumonia; dosages more than 10 mg/d or cumulatively 700 mg of prednisone increased patients' risk of pulmonary infection.

Asplenic patients

These patients are at particularly high risk for acquiring infections from encapsulated organisms.They also have a higher rate of infection from pneumonias overall.

Hyperglycemia and diabetes

Hyperglycemia and diabetes cause neutrophil dysfunction and are independent predictors of poor outcomes in patients with pneumonia.



RATE OF PNEUMONIA IN HIV

In patients with HIV who are infected with S pneumoniae, the risk of pneumonia is 10-100 times greater than non-HIV infected persons.

In patients with PCP, risk of infection is strongly correlated with CD4 count. In patients with a CD4 count between 201 and 350, the incidence was 0.5%.



MORTALITY AND MORBIDITY RATES FOR HIV-ASSOCIATED PNEUMONIA

From 1999-2000, the leading cause of death was from PCP. More than 50% of patients who died were not on or were not adherent to HAART.

The case-fatality rate in patients with TB is higher in patients co-infected with HIV.
For community-acquired pneumonia, the in-patient mortality rate is 9.1%. The clinical staging system predicts mortality: neurologic symptoms, elevated respiratory rate, and elevated creatinine.

CLINICAL PRESENTATION

Patient history

The underlying cause of immunosuppression is a crucial aspect of the history.
Nonspecific findings may include the following:
  • Fever
  • Exertional dyspnea, followed by dyspnea at rest with progression of disease
  • Cough, most often nonproductive in patients with acquired immunodeficiency disease (AIDS)
  • Pleuritic chest pain
  • Anorexia and weight loss
  • Abdominal pain
Physical examination
Pulmonary findings may be nonspecific or nonexistent in immunocompromised patients.
Findings at physical examination may include the following:
  • Fever
  • Tachypnea
  • Tachycardia or bradycardia
  • Rales or crackles
  • Rhonchi
  • Decreased breath sounds
  • Dullness to percussion
  • Egophony