Pneumonia is a potentially life-threatening infection of the lungs that inflames alveoli and spurs the overproduction of purulent material. Typically afflicting neonates and seniors, the COVID pandemic has revealed the importance of proper pneumonia care for all patients. 

By Bill Pruitt, MBA, RRT, CPFT, FAARC


Pneumonia is a potentially life-threatening infection of the lungs that inflames alveoli and spurs the overproduction of purulent material. Typically afflicting neonates and seniors, the COVID pandemic has revealed the importance of proper pneumonia care for all patients. This article will discuss the different etiologies of pneumonia (including bacterial, viral, fungal), the rise in cases as a result of COVID-19, the ongoing challenge of CAP/HAP/VAP, differences in adult versus pediatric care, and successful strategies for preventing severe cases.

Etiology, Diagnosis, Treatment

With breathing, we inhale air along with whatever is in the air around us—including dust, pollen, smoke, etc, and droplets/aerosols generated by people when they talk, cough, or sneeze. These inhaled items often carry microorganisms (bacteria, viruses, fungi) and as a result, the respiratory tract works constantly to prevent infections from starting. Inhaled air is filtered through the nose, particles are trapped and moved out through the mucociliary system, coughing or sneezing helps remove foreign items, and the immune system is present to defend against microorganisms through several mechanisms. However, infections may occur if the body’s defense systems are compromised, if there is a large “load” of microorganisms that overwhelms the barriers and defenses, or if the microorganisms are highly infectious (referred to as “virulent”). If an infection occurs, the result may be limited to the upper airway (ie, rhinitis, laryngitis), or move to the bronchi (resulting in bronchitis), or may reach the alveoli (resulting in pneumonia) .

Pneumonia is classified as either community-acquired pneumonia (CAP) which can occur in the out-patient setting or early in a hospital admission, or a hospital-acquired pneumonia (HAP) if it occurs > 48 hours of admission with nonintubated patients (also referred to as a nosocomial pneumonia). A subset of HAP is ventilator-associated pneumonia (VAP), which is a pneumonia that occurs >48 hours after intubation.1 Bacterial pneumonia is the most common type of pneumonia with streptococcus being the most common bacterial organism in the US.2 Viruses cause about a third of all pneumonias and viral pneumonia can lead to development of bacterial pneumonia. (See Table 1 for the common viral, bacterial, and fungal , causes of pneumonia). 


Table 1. Common viral, bacterial, and fungal organisms in pneumoniae2

Viral PneumoniaBacterial PneumoniaFungal Pneumonia
• Influenza viruses
• Cold viruses
• RSV
• SARS-CoV-2
• Measles virus
• Adenovirus
• Varicella-zoster		• Streptococcus pneumoniae 
• Mycoplasma 
• Legionella
• Certain types of chlamydia bacteria
• Bordetella pertussis (whooping cough)		• Coccidioidomycosis (causes valley fever)
• Cryptococcus 
• Histoplasmosis


Symptoms of pneumonia include sharp or stabbing pain when coughing, frequent, productive cough, fatigue, fever and chills, gastrointestinal issues (nausea, vomiting, diarrhea), shortness of breath and increased work of breathing, signs of cyanosis/hypoxemia, confusion, and tachycardia.1-2 Diagnosis is often based on clinical signs and symptoms along with radiographic evidence. For patients who need hospitalization, lab work often includes blood cultures, sputum gram stain and culture, tests for S. pneumoniae and Legionella, and testing for SARS-CoV-2.1 

Treatment is guided by the causative agent. Antibiotics are used for bacterial pneumonia, antiviral agents are used for viral pneumonia, and antifungal agents are used for fungal pneumonias. Treatment may be done at home for milder cases, while more serious infections call for hospital admission and may involve admission to intensive care. Supportive care is needed to ensure proper hydration and nutrition to boost the immune system, supplemental oxygen (including high-flow nasal cannula therapy), assistance in breathing (including noninvasive ventilation and/or mechanical ventilation), inhaled bronchodilators for bronchospasm/wheezing, and therapy for secretion clearance.

Impact of COVID-19

The first appearance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was in December 2019 with a subsequent pandemic occurring world-wide (the COVID-19 pandemic). Pneumonia caused by COVID-19 has been significant in causing serious morbidity and mortality, and the medical approaches to handling COVID-19 pneumonia are still being studied to find what works best. At the same time, the coronavirus has been evolving.3 While most countries have declared that the pandemic is over and that vaccines are preventing the most severe, life-threatening situations for most people, prevention and treatment of this disease is still ongoing.4 Many people have received the vaccination and some or all of the subsequent boosters and many have had COVID-19, which has activated their immune system to respond to the coronavirus if re-exposure occurs. These factors have reduced the seriousness of getting COVID-19. This is reflected in the updated isolation guidelines published in March 2024 from the Center for Disease Control and Prevention (CDC). The update recommends approaching COVID-19 in the same way as approaching other respiratory viruses, influenza, and respiratory syncytial virus (RSV). However, the disease is still a serious issue, particularly for the elderly and those with a compromised immune response.5 

The approach to treating COVID-19 pneumonia has shifted but the best strategy is still not settled within the medical community. Part of the difficulty lies in the fact that the clinical presentation of those infected ranges from being asymptomatic to having severe respiratory failure. Some COVID-19 patients demonstrate a unique feature in having severe hypoxemia but a comparatively low level of dyspnea. Also, although patients meet some of the recognized qualifications of having severe ARDS (having a PaO2/FiO2 or P/F ratio <100 mmHg, bilateral pulmonary infiltrates, non-cardiac origin), the usual ARDS condition described as the “baby lung” does not fit. In the pathophysiology and early clinical stages of the disease these patients have much larger areas of functioning lung tissue—more of an “adult” lung.3 

Hypoxemia in COVID-19 has been treated with a range of approaches, beginning with the usual low-level oxygen devices (nasal cannula, air-entrainment mask, partial or non-rebreather mask) to high-flow nasal cannula, to mask (or helmet) continuous positive airway pressure (CPAP), to noninvasive ventilation (NIV) by mask, coupled with prone positioning. Intubation and mechanical ventilation is the next step in providing support and refractory hypoxemia is often the driving factor in making this step. However, it is recommended that other variables be measured and evaluated in taking this step, such as changes in PaCO2, respiratory rate, spontaneous tidal volume, and patient-initiated lung stress and strain.3 Also, trying to correct hypoxemia needs to be tempered by lung-protective strategies and accepting lower level of oxygenation in order to protect the lung appears to have better survival.3 

Some 3% of patients with severe COVID-19 have received extracorporeal membrane oxygenation (ECMO), with a survival rate of about 51%. There are several factors that contribute to the success or failure of ECMO that should be considered when deciding to take this step. These include the patient’s pre-existing comorbidities, the ECMO approach being utilized (veno-venous, veno-arterial, or hybrid) and the experience/case load of the ECMO center.3

The Ongoing Challenge of CAP/HAP/VAP 

CAP is associated with a range of symptoms, from mild cases presenting with a fever and productive cough to severe cases involving respiratory distress and sepsis. Following urinary tract infections, CAP is the second most common cause of hospitalization but is number one in causing infection-related death.1,6 Risk factors for CAP include older age, chronic comorbidities (with COPD at the highest position), viral respiratory tract infections (particularly influenza virus), impaired airway protection that increase aspiration issues, smoking and alcohol overuse, and other lifestyle issues (i.e. prisoners, those in homeless shelters or low-income housing, and chronic exposure to environmental agents such as solvents, paint, or gasoline).1 In CAP, Streptococcus pneumoniae (pneumococcus) and respiratory viruses (with an increasing incidence of COVID-19 related cases) are the most frequent causative agents, but with the increasing use of pneumococcal vaccination, incidence of S. pneumoniae is decreasing.1,7

Only about half of CAP cases are given an identified pathogen (most mild cases can be treated without needing this identification), and for those with this detail, about one-third (in adults) are caused by viruses. However, testing for COVID-19 and influenza is often performed since the outcome may change the therapeutic approach.1,7 Treatment is based on antibiotics and support for the patient, depending on their health status and response. Antibiotic resistance is becoming more of a problem, particularly in cases of methicillin-resistant Staphylococcus aureus (MRSA), which is mentioned many times in the various strategies for fighting CAP from the American Thoracic Society and Infectious Diseases Society of America (ATS–IDSA).7-8 CAP can be very serious with death within a year occurring in about 30% of all who are hospitalized and around half of patients who are admitted into ICU.7

HAP is defined by the pneumonia appearing >48 hours after admission and is one of the most common nosocomial infections.9 The primary cause of HAP is microaspiration of oropharyngeal secretion that have been colonized by pathogens acquired in the hospital. As with CAP, there is a growing problem with antibody-resistant pathogens like MRSA, and some organisms are becoming resistant to multiple antibiotics (described as multidrug-resistant or MDR) pathogens).9 The ATS-IDSA guidelines for management of HAP recommend basing a clinical diagnosis on the appearance of a new lung infiltrate that is linked to an infectious origin as shown by new onset of fever, purulent sputum, leukocytosis (high white blood cell count) and a decrease in oxygenation.8 However, research looking at various combinations of signs and symptoms have not found any that are highly sensitive or specific for diagnosis.9 As in CAP, treatment is based on antibiotics, with several strategies described by the ATS-IDSA guidelines that depend on the causative agent, the patient’s health status, possible side-effects, drug tolerance, response, etc.8-9 Supportive care is provided as needed and may include the same approach as seen with COVID-19 treatment from respiratory care.

VAP is defined by the appearance of a pneumonia that occurs >48 hours after intubation. The same issues seen with HAP (described above) are seen in VAP, with the additional problems associated with placement of an endotracheal tube. These problems involve the bypassing the larynx and vocal cords which opens a direct entrance from the upper airway to the lower airway, loss of an effective cough, and increased risk of aspiration, plus possible issues with contaminated tubing, etc. Some studies have reported a steady decline in VAP rates in the U.S. while other sources suggest that the rate of VAP is holding steady.9 This discrepancy reflects “the lack of definitive criteria for VAP and the subjectivity of surveillance.”9 Treatment for VAP follows the same path seen in treating HAP: antibiotics used on a case-by-case basis, and supportive care.

Care Models for Adult Versus Pediatric Cases

Care models for adult patients with pneumonia has been described above. Most of the research into diagnosis, treatment, and prevention has been in the adult population, with little published in the pediatric population.10 This is unfortunate since pneumonia, looking at global statistics, is the leading cause of death in children <5 years of age.10 However, research looking at 132 developing countries has seen a decrease in pneumonia by 22% from 2000 to 2015. This is based on many factors including economic development, improved nutrition, reduced numbers of people in the household, increased use of appropriate antibiotics, and administration of effective vaccines in the pediatric population.10 Respiratory syncytial virus (RSV) is more of an issue in causing pneumonia in pediatric patients than in adults (except for the elderly and adults with severe lung disease).11 In cases of CAP in children, some 60%-90% are suspected to be of viral etiology and care is directed to relieving symptoms and treating issues such as hypoxemia, excessive secretions etc. However, if a bacterial component is suspected to be present, antibiotics are used in much the same way as in adults, and often physicians will utilize antibiotics.10 

Note that in pediatric and neonatal ICU patients, VAP is the second most common HAP and steps to avoid this issue are a must.12

Preventing Severe Cases

Severe pneumonia increases cost, length-of-stay for hospitalizations, increased need for ICU admission and possible intubation/mechanical ventilation, and carries an increased mortality for these patients. Prevention of severe pneumonia follows the same foundation as overall prevention of pneumonia. Vaccination against bacterial pneumonia helps reduce incidence of Haemophilus influenzae type b (Hib), pertussis (whooping cough), and pneumococcal pneumonia. Recommended immunizations that fight viral infections help fight issues with COVID-19, influenza (flu), measles, RSV, and varicella. 

People should avoid others who are sick and if one is sick, isolating is recommended to prevent transmission of pathogens. Other practical steps in preventing pneumonia include careful handwashing, cleaning and disinfecting surfaces that may serve as transmission sites, following cough/sneeze etiquette, quitting smoking and avoiding cigarette smoke, and taking steps to manage chronic conditions such as asthma and COPD. 13 Recommendations for avoiding HAP/VAP include:14

  • Use of high-flow nasal oxygen and/or noninvasive ventilation if appropriate
  • Avoid intubation and prevent reintubation if possible
  • Minimize use of sedation and follow a protocol for sedation vacations
  • Follow a protocol for weaning and discontinuing mechanical ventilation (MV) to minimize time on MV
  • Elevate the head of the bed 30o to 45o
  • Provide early exercise and mobilization
  • Perform oral care with toothbrushing
  • Provide early enteral nutrition
  • Only change ventilator circuits if visibly soiled or malfunctioning
  • Diagnose and manage dysphagia to reduce risk of aspiration
  • Implement ventilator bundles and pneumonia prevention bundles
  • Monitor, measure, and report outcomes on incidence of pneumonia
  • Educate staff on bundles and monitoring results
  • Incorporate changes to address areas of weakness, lack of compliance

Conclusion

Pneumonia is a frequent issue in the community and in the hospital, with VAP being a serious component in the HAP arena. Strategies to manage pneumonia are constantly being reviewed and updated guidelines are frequently appearing as more research is finished. It is important to keep abreast of the changes as they come out in order to provide the best, safest, and most effective care for the patient with pneumonia. There are common steps of care and common steps for prevention that cross from CAP to HAP to VAP, but the details and particulars for care in each group is important and should not be overlooked.

RT

Bill Pruitt, MBA, RRT, CPFT, FAARC, is a writer, lecturer, and consultant. Bill has over 40 years of experience in respiratory care in a wide variety of settings and has over 20 years teaching at the University of South Alabama in Cardiorespiratory Care. Now retired from teaching, Bill continues to provide guest lectures, participates in podcasts, and writes professionally. For more info, contact [email protected].


References

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