Day 1:

Pneumonia

Pneumonia is most common and dangerous in very young children, people over the age of 65, and people with underlying medical conditions such as heart disease, diabetes, or chronic lung disease. This patient who comes from a nursing home will most likely have Nursing home acquired pneumonia (NHAP). It is one of the most common infectious diseases in long term care facilities and is a significant cause of mortality and morbidity among residents of such facilities. Dysphagia has been identified as a risk factor. This type of pneumonia closely resembles community acquired pneumonia. 

The pathophysiology of NHAP is the same as CAP

NHAP may result when a patient aspirates oropharyngeal contents into 1 or more lung lobes. It may also occur is distant focus of infection hematogenously disseminated to the lungs 

Type of PNA

NHAP – 

• mc pathogens: strep pneumo, h influenza, moraxella catarrhalis
• uncommon pathogens: legionella, chlamydophila pneumo
• Chest X-ray: Focal sequential/lobar ± consolidation ± pleural effusion. No cavitation 
• Length of stay: 7-10 days

CAP

• mc pathogens: S pneumoniae, H influenzae, M catarrhalis
• uncommon pathogens: legionella, Mycoplasma
• Chest x-ray: Focal sequential/lobar ± consolidation ± pleural effusion. No cavitation
• 7-10 days

NP (nosocomial pneumonia)

• mc pathogens: Pseudomonas aeruginosa, Klebsiella, Escherichia coli
• Uncommon pathogens: serratia
• Chest x-ray: Necrotizing pneumonia and cavitation with P aeruginosa and Klebsiella. Bilateral infiltrates without cavitation or pleural effusion
• 10-21 days

Symptoms: 

• most patients are febrile and may be low grade
• Chills, SOB, chest pain with breathing, tachycardia and tachypnea, N/V/D, cough that produces green or yellow sputum 
• Patient may have low oxygen saturation 

Physical examination: 

fever, dullness to percussion, egophony, tachycardia, and tachypnea. Asymmetric breath sounds, pleural rubs, egophony, and increased fremitus 

Rales or bronchial breath sounds 

Tachypnea is common in older patients with CAP, occurring in up to 70 percent of those older than 65 years. Pulse oximetry 

DX

• Obtain blood cultures (mostly s pneumo or h flu)
• CBC – leukocytosis with a left shift may occur in NHAP (also common with an acute MI, PE, dehydration or other causes of stress)
• Sputum staining and culture 
• Urine testing – can be helpful for diagnosing pneumonia caused by two bacteria (strep pneumo and legionella)
• Chest x-ray 

Antibiotic therapy 

• empiric therapy – coverage against the most likely pathogens 
• Duration of therapy is usually 2 weeks  
• first line: Macrolide (azithromycin or clarithromycin), or tetracycline (doxycycline)
• Fluoroquinolone abx
• Augmentin 

Complications 

• pleural effusion 
• Abscess 
• Bacteremia 
• Cardiovascular events 

 

Day 2:

Pathogenesis 

• the coronavirus that causes COVID-19 is a betacoronavirus in the same subgenus as the severe acute respiratory syndrome (SARS) virus (as well as several bat coronaviruses). 
• Corona virus was typically surrounding around bats – a natural animal reservoir – mutated and caused disease in humans
• The structure of the receptor-binding gene region is very similar to that of the SARS coronavirus, and the virus has been shown to use the same receptor, the angiotensin-converting enzyme 2 (ACE2), for cell entry
• Person-to-person spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is thought to occur mainly via respiratory droplets
• virus released in the respiratory secretions when a person with infection coughs, sneezes, or talks can infect another person if it makes direct contact with the mucous membranes; infection can also occur if a person touches an infected surface and then touches his or her eyes, nose, or mouth.
• Droplets typically don’t travel more than 6 feet and do not linger in the air 
• appears that SARS-CoV-2 can be transmitted prior to the development of symptoms and throughout the course of illness
• Viral RNA levels from upper respiratory specimens appear to be higher soon after symptom onset 
• suggested infectiousness started 2.3 days prior to symptom onset, peaked 0.7 days before symptom onset, and declined within seven days
• How long a person remains infectious is also uncertain. The duration of viral shedding is variable; there appears to be a wide range, which may depend on severity of illness

Clinical features 

• median age ranged from 49 to 56 years
• The incubation period for COVID-19 is thought to be within 14 days following exposure, with most cases occurring approximately four to five days after exposure
• The spectrum of symptomatic infection ranges from mild to critical; most infections are not severe
  • Mild (no or mild pneumonia) was reported in 81 percent – some don’t develop any symptoms 
  • Severe disease (eg, with dyspnea, hypoxia, or >50 percent lung involvement on imaging within 24 to 48 hours) was reported in 14 percent.
  • Critical disease (eg, with respiratory failure, shock, or multiorgan dysfunction) was reported in 5 percent.
  • Of over 900,000 cases and 45,335 deaths – fatality rate of 5% – however – current studies suggest its lower (.7%) – because of many undiagnosed/ asymptomatic carriers
  • Comorbidities that have been associated with severe illness and mortality include:
  • Cardiovascular disease
  • Diabetes mellitus
  • Hypertension
  • Chronic lung disease
  • Cancer
  • Chronic kidney disease
  • Obesity (body mass index ≥30)
• Asymptomatic infections can also be common (around 25% of those infected)

Initial Presentation

• Pneumonia seems to be the most frequent serious manifestations of infection – fever, cough, dyspnea, bilateral infiltrates on chest imaging – there is currently no specific clinical features that can reliably distinguish COVID 19 from other viral respiratory infections
• Fever (99%)
• Fatigue
• Dry cough 
• Anorexia
• Myalgias
• Dyspnea 
• Sputum production (27%)
• Smell and taste disorders have also been a common symptom 
• Less common – headache, sore throat, and rhinorrhea 
• GI symptoms 

 

• ARDS is a major complication in patients with severe disease and can manifest shortly after the onset of dyspnea 
• Other complications – arrhythmia, acute cardiac injury and schlock 

 Diagnosis/ Lab findings

• Leukopenia, leukocytosis and lymphopenia (the most common)
• Elevated LDH, ferritin, liver enzymes 
• Imaging – Chest X-ray – consolidation and ground glass opacities, with bilateral, peripheral and lower lung zone distributions 
• Lung involvement increased over the course of illness – peak in severity at 10-12 days after symptom onset
• Chest CT in patients with COVID-19 most commonly demonstrates ground-glass opacification with or without consolidative abnormalities, consistent with viral pneumonia
• Diagnosis is made with Reverse transcriptase polymerase chain reaction
• the CDC recommends collection of a nasopharyngeal swab specimen
• A positive test for SARS-CoV-2 generally confirms the diagnosis of COVID-19.
• If influenza is circulating in the community, it is reasonable to also test for influenza when testing for SARS-CoV-2

Sources: 

UpToDate

Osmosis

Medscape