Pneumonia

Written by: Dr. Sabrina Lee

Edited by: Dr. Joann Hsu

The case

17 yo female with no pmhx, UTD vaccines initially in ED for fever (Tmax 101F), productive cough, diarrhea, body aches x 1 week. Testing showed (+) strep and RLL pneumonia. RPP was negative. D/c with Rx of Amoxicillin.

Patient returned 5 days later due to persistent fever and cough and worsening SOB despite outpatient Amoxicillin. She was taking tylenol and motrin at home.


Physical Exam

  • BP 121/79, Hr 103, RR 28, T 36.9C, SpO2 86% on RA → 91% on 4L NC

  • GENERAL: Well-nourished, well-developed, well-hydrated, no distress. Vital signs reviewed.

  • OROPHARYNX: Moist mucus membranes.  No erythema, no ulcers, no exudate. Neck is supple, no masses.

  • CARDIOVASCULAR/HEART: Regular rate & rhythm, normal S1/S2, no murmurs, no rubs, no gallops, normal peripheral pulses.

  • RESPIRATORY/CHEST: Tachypnea, hypoxia. Decreased breath sounds to the right lung, especially to the right lower lobe.


Labs: CRP elevated to 26.30. Procalcitonin within normal limits. CBC, BMP unremarkable. EPOC unremarkable. 

  • RPP: (+) Mycoplasma pneumoniae

Imaging:

  • CXR: Interval increase in right lower lobe consolidation consistent with pneumonia with adjacent probable pleural effusion.

  • CT Chest: Near complete right lower lobe consolidation and mild patchy right upper and middle lobe opacities consistent with multifocal pneumonia. Small right pleural effusion.

Bedsde Lung POCUS:

Left lung showed normal lung sliding without B-lines, hepatization, or signs of pleural effusion.

Right lung showed normal lung sliding without B-lines. There was significant hepatization of right lower lobe (more on this later) consistent with pneumonia. Some static air bronchograms noted. Spine sign was seen consistent with pleural effusion.

Characteristics of Pneumonia on Ultrasound:

  • B-lines - especially focal B lines

  • Subpleural Consolidations (C-lines)

  • Pleural Thickening

  • Shred Sign - irregularity of the pleura, looks “shredded”

  • Hepatization - where the lung looks like liver!

  • Air Bronchograms

B-Lines: hyperechoic vertical rays from pleural line; localized patches suggest early pneumonia

Subpleural Consolidation (C-lines): cone or dome-shaped consolidations along pleural line; suggests early pneumonia

Pleural Thickening

Shred Sign: irregularity in pleural line, indicating the order between normal aerated lung and fluid/pus-filled lung

Hepatization: dense-appearing consolidation of the lung; seen when lung is completely fluid/pus-filled (pneumonia) or completely collapsed (atelectasis)

Air Bronchograms: small hyperechoic blebs indicated trapped air

  • Dynamic: movement of air with respiration (as seen in pneumonia) - see first clip

  • Static: no movement of air with respiration; indicates air is trapped by an obstruction (as seen in atelectasis) - see second clip

Ultrasound Features of Pneumonia by Pathogen:

Lung Abscess

  • Pus-filled cavity within lung tissue

  • Commonly caused by aspiration

  • Common pathogen: Staph aureus

  • Symptoms:

    • Fever

    • Cough

    • Sweats

    • Weight loss

Lung Empyema

  • Pus collection within pleural space

  • Common pathogen: Staph aureus

  • Symptoms:

    • Fever

    • Chest pain

    • Cough

    • Sweats

    • Weight loss

Which is better - chest XR or US?

Study #1:

A systemic review of multiple studies examining the sensitivity, specificity, and overall accurate of lung US compared to CXR in diagnosing pneumonia

  • Conclusion; US is generally more sensitive and specific over CXR in multiple studies

    • Lung US is effective and advantageous across all age groups (pediatric, geriatric, adults)



Study #2:

A prospective, observational study that examined sensitivity and specificity of lung US and CXR in diagnosing pneumonia in a resource-limited setting, specifically Nepal

  • Conclusion: LUS had better sensitivity than CXR to diagnose PNA in Nepal

    • Sensitivity: LUS 91% vs CXR 73%

    • Specificity: LUS 61% vs CXR 50%


Study #3:

A single-center, prospective, observational study that examined the sensitivity and specificity of lung US and CXR in diagnosing COVID-19 pneumonia at an urban university

  • Conclusion: LUS had better sensitivity than CXR to diagnose COVID-19 PNA

    • Sensitivity: LUS 97.6% vs CXR 69.9%

    • Specificity: LUS 33.3% vs CXR 44.4%

Benefits to Lung US

  • Cost-effective

  • Portable (at bedside)

  • Safety (less radiation)

  • Quicker to perform than CXR

  • More sensitive at diagnosing pneumonia than CXR



Limitations to Lung US

  • Operator dependent

  • Patient limitations (habitus, subcutaneous emphysema, large thoracic dressings)

  • Unable to detect hyper-inflated lung fields from increased intrathoracic pressures

  • Requires extra time by operator

  • Can miss lesions that do not extend to pleura (similar to CXR)



Back to our patient…

ED:

  • Patient required 5L NC and desatted to high 80s on RA

  • CT surgery consulted for possible chest tube placement but deemed not necessary at the time and to admit

  • Treated with 1L NS fluids and IV levofloxacin

  • Admitted to pediatric floors

Floors:

  • Hospitalized for 4 days

  • Completed 5-day course Azithromycin and 3-day course Unasyn

  • Discharged with Azithromycin & Augmentin


Happy scanning!

References

  • Abid I, Qureshi N, Lategan N, Williams S, Shahid S. Point-of-care lung ultrasound in detecting pneumonia: A systematic review: Published in Canadian Journal of Respiratory therapy. Canadian Journal of Respiratory Therapy. January 29, 2024. Accessed January 26, 2025. https://cjrt.ca/article/92182-point-of-care-lung-ultrasound-in-detecting-pneumonia-a-systematic-review. 

  • Amatya Y, Rupp J, Russell FM, Saunders J, Bales B, House DR. Diagnostic use of lung ultrasound compared to chest radiograph for suspected pneumonia in a resource-limited setting. Int J Emerg Med. 2018;11(1):8. Published 2018 Mar 12. doi:10.1186/s12245-018-0170-2

  • Boccatonda A, Cocco G, D’Ardes D, et al. Infectious pneumonia and lung ultrasound: A Review. Journal of clinical medicine. February 10, 2023. Accessed January 26, 2025. https://pmc.ncbi.nlm.nih.gov/articles/PMC9964129/. 

  • Gibbons RC, Magee M, Goett H, et al. Lung Ultrasound vs. Chest X-Ray Study for the Radiographic Diagnosis of COVID-19 Pneumonia in a High-Prevalence Population. J Emerg Med. 2021;60(5):615-625. doi:10.1016/j.jemermed.2021.01.041

  • Koratala A, says: jose de jesus C, says: AK. Pneumonia and Dynamic Air Bronchograms. NephroPOCUS. May 22, 2020. Accessed January 26, 2025. https://nephropocus.com/2019/07/01/dynamic-air-bronchograms-ultrasound-sign-of-pneumonia/. 

  • Lung. MMHEME. Accessed January 26, 2025. https://www.mmheme.org/lung. 

  • Rippey J. Lung ultrasound: Pneumonia. Life in the Fast Lane • LITFL. August 23, 2022. Accessed January 26, 2025. 

  • Ultrasound diagnosis of pneumonia. Emory University Shield. Accessed January 26, 2025. https://med.emory.edu/departments/emergency-medicine/sections/ultrasound/case-of-the-month/lung/pneumonia.html. 

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