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Anatomy and Etiology

Pneumonia is an infection of the lung parenchyma. It is caused by viruses, bacteria, fungi, and parasites and includes interstitial tissue and alveolar spaces. Pneumonia can present as a complication of another illness or disease or it can be a primary condition as a result of different organisms (Bartolf & Cosgrove, 2016). The classification of pneumonia is based on where and how it was acquired. The different classifications of pneumonia are: 1) community acquired pneumonia – where the patient has not been in the hospital or a nursing home within the last fourteen days; 2) hospital acquired (nosocomial) pneumonia – where the patient acquires pneumonia forty eight hours or more after being admitted to the hospital; 3) ventilator acquired pneumonia – where the patient acquires pneumonia forty eight hours or more after being intubated; and 4) healthcare associated pneumonia – where the patient has had two or more days of contact with someone in the healthcare system within the last ninety days (Bartolf & Cosgrove, 2016).

Risk factors. There are several risk factors associated with pneumonia such as: chronic lung disease, being in an immunocompromised state, gastroesophageal reflux disease, environmental or animal exposure, recent influenza infection, injection drug abuse, institutional residence, impaired mentation with aspiration risk, and other iatrogenic risk factors (Bartolf & Cosgrove, 2016).

Pathophysiology

The exact pathology of pneumonia depends upon the overall health of the patient, the age of the patient, the type of organism, and the size of the pathogen. Pneumonia is a result of the entry and growth of certain pathogens which enter the lung parenchyma (Mattila, et al., 2014). Typically, bacterial pneumonia is a result of a common organism found in the upper respiratory tract that are transferred to a patient who may be at a higher risk for infection (Mattila et al., 2014). It is transmitted through airborne droplets which then migrate to the lower respiratory tract. The most common cause of bacterial pneumonia is streptococcus (Mattila et al., 2014). Other types of bacteria that cause pneumonia are mycoplasma pneumoniae, legionella pneumophila, chlamydophila pneumoniae, streptococcus pyogenes, klebsiella pneumoniae, staphylococcus aureus, neisseria meningitides, haemophilus influenza, and moraxella catarrhalis (Mattila et al., 2014). Viral pneumonia is often a result of an organism which begins in the upper respiratory tract and moves to the terminal bronchioles as would be seen in a respiratory syncytial virus or in influenza. It can also originate from organisms which enter the upper respiratory airways and then spread through until it reaches the lower respiratory tract, as would be seen in measles. The most common viruses that cause viral pneumonia are parainfluenza, influenza A, B, and C, adenovirus, respiratory syncytial virus, rhinovirus, and coronavirus (Mattila et al., 2014). Pneumonia can similarly be the result of a fungal infection which is common in patients who are immunocompromised, for example, pneumocystis jiroveci, cryptococcus, and histoplasma capsulatum (Mattila et al., 2014).

With pneumonia, pathogens normally enter the upper respiratory tract through micro-aspiration (Driver, 2012). Certain chronic conditions (heart failure, cancer, diabetes, renal failure and chronic respiratory disorder) as well as an ageing immune system can decrease the body’s ability to fight off these pathogens. The pathogens pass in to the lower respiratory tract and can overwhelm the macrophages (Driver, 2012). This results in an inflammatory response which causes a production of intra-alveolar exudate. The exudate fills the alveolar spaces and causes them to stick together, resulting in them becoming airless (Driver, 2012). An increased production of neutrophils is also caused from the inflammatory response which can lead to pulmonary edema, fibrosis, damage of the lungs, and pleural effusion. These changes ultimately result in a decreased gas exchange which can lead to decreased oxygen to the organs and an overall disruption of normal physiology (Driver, 2012). The practitioner can expect to see heart rate and respiratory rate elevated due to oxygen levels falling and carbon dioxide rising.

Consequences: adult and geriatric. The older patient is less able to fight off infections due to an aging immune system as are the very young. They are more susceptible to infections and sometimes cannot respond to treatment (Teramoto, Yoshida, & Hizawa, 2015). Added issues to consider with the older patient are chronic renal failure, leaner body mass, and polypharmacy issues which can limit the choice of treatment (Teramoto, Yoshida, & Hizawa, 2015). Other things to take in to account are decreased elasticity of the lungs and decreased strength of respiratory muscles. Weakening of the alveoli can also result in senile emphysema and a decrease of the diameter of the airways can furthermore cause a higher workload on the respiratory muscles (Teramoto, Yoshida, & Hizawa, 2015). With the older patient as well as the very young patients, it is important for caregivers to ensure that the patient remains well hydrated, receives adequate nutrition, and is compliant with the prescribed treatment (Teramoto, Yoshida, & Hizawa, 2015).

Epidemiology

Pneumonia continues to be a significant health problem across the globe. Despite the availability of antibiotics, pneumonia remains a large cause of mortality around the world (Bartolf & Cosgrove, 2016). Every year, approximately one and a half million people die from this disease. It is considered to be the most common cause of death among children throughout the world (Bartolf & Cosgrove, 2016). It is also one of the more common causes of mortality among geriatric groups in industrialized countries.

Cultural, age, race, gender, US, international. Using a nationwide claims database, a retrospective study used to determine the incidence of community acquired pneumonia in the Netherlands identified close to two hundred thousand cases of CAP between 2008 and 2011, which represented and average incidence of almost three hundred cases per one hundred thousand population per year (Juckett, 2015). The authors of the study determined that the mean annual cost of CAP in this population was approximately one hundred seventy eight million euros, with seventy six percent of the cost resulting from people older than fifty years of age. The elderly are associated with having a higher incidence of CAP and also with having a more severe case of the disease, having a greater need for hospitalization, and also having a higher mortality rate (Juckett, 2015).

Prognosis

The severity of community acquired pneumonia is related to short term mortality. Mortality is less than one percent in patients who are appropriately treated as outpatient. The rate goes up to eight percent in patients who are hospitalized for treatment (Maury, London & Offenstadt, 2015). It is believed that the cause of death may be related to the pneumonia, progression to sepsis, or an exacerbation of coexisting conditions. Patients who have been hospitalized for treatment of pneumonia are at an increased risk of death during the year after being discharged (Maury, London & Offenstadt, 2015). The mortality rate depends to some degree on the pathogen. Mortality rates are increased with gram-negative bacteria and CA-MRSA. However, S. pneumonia is the most common cause of death in patients with CAP due to the high incidence of this pathogen. Atypical pathogens have a better prognosis. Mortality is higher when patients do not respond to initial antibiotics and in patients whose treatment regimen does not conform to guidelines (Maury, London & Offenstadt, 2015).

Patient Education

Patients should be educated on prevention, namely vaccines to help decrease the chances of contracting certain types of bacterial and viral pneumonia. The influenza vaccine can help prevent seasonal influenza which is a common cause of pneumonia (Mattila et al., 2014). The pneumococcal polysaccharide vaccine can also help prevent a common bacterial form of pneumonia. Other types of vaccines that can help prevent viral and bacterial illnesses that lead to pneumonia are pertussis, Haemophilus influenza type b, measles, and varicella (Mattila et al., 2014).

Treatment Evaluation

Approach Considerations

Guidelines. When determining the treatment for CAP, the clinician needs to first determine if hospitalization is required or if the patient can safely be treated on an outpatient basis. The American Thoracic Society (ATS) guidelines recommend for clinicians to use validated clinical decision tools for risk stratification such as the Pneumonia Severity Index (PSI) or CURB-65 (confusion, urea nitrogen, respiratory rate, blood pressure, sixty five years of age and older) to help identify patients who may require hospitalization or can be safely treated on an outpatient basis (Watkins & Lemonovich, 2011). It is typically recommended that patients with no prior history of respiratory or cardiac disease and who present to the clinic with mild to moderate symptoms can be treated on an outpatient basis with close monitoring by their general practitioner (Watkins & Lemonovich, 2011). However, patients with a history of chronic respiratory, cardiac, or neurological conditions who are also immunocompromised are at a higher risk and would need to be considered for hospital admission (Watkins & Lemonovich, 2011). Patients who have not responded to an appropriate course of oral antibiotics should also be considered for hospital admission. The clinician should also consider the patient’s social structure and support in the community when making this decision (Watkins & Lemonovich, 2011).

Complications

Complication with community acquired pneumonia usually happen when the diagnosis is delayed because the patient does not present with symptoms in the early stages or the patient is initially diagnosed incorrectly (Clinical Protocol Pneumonia, 2011). The wrong choice of initial antibiotics also delays the proper treatment. Complications are more often seen with bacterial pneumonia rather than viral pneumonia. Some of the most common complications of CAP are: lung abscess, pleural effusion, lung cavitation, serious hypotension which causes severe hemodynamic changes, acute respiratory failure, and sepsis. CAP can also cause mild confusion, mild anemia, mild jaundice, arthritis, and hemoptysis (Clinical Protocol Pneumonia, 2011).

Health Promotion and Risk Reduction

The patient should have a clear understanding of their diagnosis, the treatment plan, and follow up appointments (Clinical Protocol Pneumonia, 2011). If the patient is a smoker, a referral to a smoking cessation program should be made during the initial visit. For the patient being treated for mild to moderate CAP, a follow up should be conducted within forty eight hours to assess the patient’s response to the treatment (Clinical Protocol Pneumonia, 2011). The patient should be referred to the emergency department if their condition worsens after forty eight hours of initial treatment. If the patient is responding after forty eight hours, a follow up appointment should be scheduled in one week (Clinical Protocol Pneumonia, 2011).

Medicolegal Concerns

As with all aspects of the medical field, there are medicolegal issues to contend with. As previously mentioned, misdiagnosing a patient which will delay treatment can cause major complications with the patient’s condition. Prescribing errors, often treating pneumonia with the wrong antibiotic, can also lead to complications with the patient’s condition (Clinical Protocol Pneumonia, 2011). Failure to communicate clearly and effectively with the patient and/or their caregiver can lead to misunderstandings of the patient’s diagnosis, treatment, and medication plan. Inadequate follow-up by the clinician can also lead to medico-legal issues (Clinical Protocol Pneumonia, 2011).

Future Research Needed

Community acquired pneumonia is a significant contributor to morbidity and mortality across the globe and especially in the elderly (Bartolf & Cosgrove, 2016). Research to better diagnose and treat this disease can significantly help reduce these occurrences. Research is also needed to improve risk stratification indices based on disease severity to predict intensive care need. Research to improve diagnostic tools can greatly contribute to early diagnosis and better targeted therapy (Bartolf & Cosgrove, 2016).

Consultation

For difficult cases of pneumonia, the clinician should consult with a pulmonary specialist and/or an infectious disease specialist (Bartolf & Cosgrove, 2016). An infection control specialist and/or a pharmacist can help provide necessary information on regional or hospital bacterial resistance and sensitivity patterns. They can also assist in prescribing appropriate antibiotic dosing and level monitoring (Bartolf & Cosgrove, 2016). If a patient requires intubation or noninvasive mechanical ventilation, a consultation with a critical care medicine specialist would be helpful to assist in managing the patient after they have been admitted to the intensive care unit (Bartolf & Cosgrove, 2016).

Long Term Monitoring

All patients who have been treated in an outpatient setting for bacterial pneumonia must arrange a follow up evaluation and should return promptly to see a clinician if their condition worsens. A follow-up chest x-ray should be done approximately six weeks later to confirm the resolution of the consolidation and to assess for any persistent abnormalities of the lung parenchyma (Driver, 2012).

Ethical and Cultural Considerations

Cultural differences can greatly influence the treatment and management of pneumonia. Many cultures turn to home remedies or seek treatment from traditional healers before seeking treatment from a conventional healthcare provider (Juckett, 2015). Some cultures believe in predetermined fate and refuse to adhere to medical treatments because they believe that the illness was “meant to be” and have spiritual, not medical, causes (Juckett, 2015). Other cultures, such as Latinos and Asians, believe a hot-cold balance is needed for health, meaning that a hot condition should be treated with cold therapies and cold conditions should be treated with hot therapies (Juckett, 2015). The clinician should take in to account the patient’s cultural beliefs in order for the patient to comply with treatment.

Cost

Pneumonia is one of the leading causes of hospitalizations and deaths in the United States. It is estimated that medical costs in 2012 exceeded ten billion dollars for adults in the US (Centers for Disease Control and Prevention, 2015).

Critical Reflection of Interaction and Investigation

The overall interaction with the patient and the staff nurse assigned to the patient was very positive. Forming an open and trustful relationship with the staff nurse was very important and helpful because the patient was disoriented and unable to provide much verbal information that was needed for the history. The nurse was very clear and detailed with the information she provided regarding the patient’s symptoms and the progression of his illness over the last few days. She was also very helpful in providing some of the history that was needed to complete the exam. My preceptor and I were able to work together in ruling out the differential diagnosis based on the patient’s symptoms and on the results of the chest x-ray. In all, it was a very good learning experience.

Test Questions

1. For a patient diagnosed with community acquired pneumonia, which of the situations listed below would be appropriate to treat the patient in an outpatient setting rather than admitting the patient:

a. A 34 year old male with community acquired pneumonia with a respiratory rate of 36, altered mental status, and a blood pressure of 92/52.

b. A 68 year old female with community acquired pneumonia with a respiratory rate of 32, confusion, and a blood pressure of 122/86.

c. A 63 year old female with community acquired pneumonia with a respiratory rate of 18 and a blood pressure of 132/78.

d. A 54 year old male with community acquired pneumonia with a respiratory rate of 34, confusion, and a blood pressure of 98/52.

2. Signs and symptoms of pneumonia typically include (select all that apply):

a. Elevated white blood cells

b. Non-productive cough

c. Stridor

d. Tachypnea

e. Coarse crackles

f. PC02 less than 35

g. Oxygen saturation less than 90%

3. A patient who was admitted to the ICU forty eight hours ago for a motor vehicle accident begins to develop a fever of 103.9 and a productive cough. The patient presents with coarse crackles in the left lower lobe and the chest x-ray displays infiltrates in the left lower lobe with consolidation. Based on the information given, what type of pneumonia does the patient have?

a. Community acquired pneumonia

b. Ventilator pneumonia

c. Aspiration pneumonia

d. Hospital acquired pneumonia

4. Of the four pathophysiological mechanisms listed below that occur in the lung parenchyma, which one allows pneumonia to develop?

a. Bronchiectasis

b. Inflammation

c. Atelectasis

d. Effusion

5. Of the following organisms listed below, which is the most common cause of community acquired pneumonia in adults?

a. Streptococcus pneumoniae

b. Haemophilus influenza

c. Staphylococcus aureus

d. Klebsiella pneumoniae

References

Bartolf, A., & Cosgrove, C. (2016). Pneumonia. Medicine, 44(6), 373-377. doi:10.1016/j.mpmed.2016.03.004

New CDC study highlights burden of pneumonia hospitalizations among US adults. (2015). Centers for Disease Control and Prevention. Retrieved from https://www.cdc.gov/media/releases/2015/p0714-pneumonia-hospitalizations.html

Clinical Practice Guideline. (2012). Hunter New England NSW Health. Retrieved from https://safetyandquality.gov.au/wp-content/uploads/2012/02/3.3-Adult-Pneumonia-CPG-CAP-HAP-combined-post-AQUM-HNE-Health.pdf

Clinical Protocol Pneumonia. (2011). Mandurah Medical Center. Retrieved from http://www.nursing.health.wa.gov.au/docs/career/np/mmc/pneumonia.pdf

Driver, C. (2012). Pneumonia part 1: Pathology, presentation and prevention. British Journal of Nursing, 21(2), 103-106. doi:10.12968/bjon.2012.21.2.103

Juckett, G. (2015). Cross-cultural medicine. American Family Physician, 72(11), 2267.

Mattila, J. T., Fine, M. J., Limper, A. H., Murray, P. R., Chen, B. B., & Lin, P. L. (2014). Pneumonia. treatment and diagnosis. Annals of the American Thoracic Society, 11 Suppl 4, S189.

Maury, E., London, J., & Offenstadt, G. (2015). Community-acquired pneumonia. The New England Journal of Medicine, 372(3), 292

Teramoto, S., Yoshida, K., & Hizawa, N. (2015). Update on the pathogenesis and management of pneumonia in the elderly-roles of aspiration pneumonia. Respiratory Investigation, 53(5), 178-184. doi:10.1016/j.resinv.2015.01.003

Watkins, R. R., & Lemonovich, T. L. (2011). Diagnosis and management of community-acquired pneumonia in adults. American Family Physician, 83(11), 1299