*For medical professionals only
Learn about emergency department knowledge every day
Severe pneumonia is a difficult clinical emergency. Legionella is one of the common pathogens of community-acquired pneumonia (CAP), and it also accounts for a large proportion of severe infections.
Today I would like to share with you a case to learn about the diagnosis and treatment of severe pneumonia and respiratory failure caused by Legionella.
Case presentation
Major medical history
Main medical history: A 67-year-old female patient was admitted to the hospital with “binaural hearing loss for 1 week, cough and sputum for 5 days”.
The patient developed binaural hearing loss and tinnitus without obvious inducement 7 days before admission. 5 days ago, the patient developed cough, yellow sputum, a large amount, and occasionally blood in the sputum, wheezing after exercise, accompanied by fever and chills, and the highest temperature was 39.2 °C.
Physical and laboratory tests
Body temperature 38.7℃, pulse (P) 112 beats/min, respiration (R) 26 beats/min, blood pressure (BP) 144/55mmHg.
Blood routine: WBC 14.04×109/L, neutrophils 95.2%, CRP 117.07mg/L.
CT scan of the chest: consolidation in the right lung, air bronchus sign, and multiple patchy shadows in the left lung. Moist rales were audible in the right lung, and both lower extremities were edematous, with no obvious abnormality.
Examination and Diagnosis
Blood biochemistry: albumin (ALB) 18.5g/L, PCT 2.15μg/L, microbial dynamic fungal monitoring 331.8ng/L, urine protein (++ ), urine red blood cells (++++), check SpO2: 89% (oxygen inhalation 3L/min), blood gas analysis (FiO: 33%): pH7.48, PO254.3mmHg, PCO236mmHg.
serum cytomegalovirus laG (+), Epstein-Barr virus capsid antigen laG (+): both blood cultures (-); Legionella urine antigen (+); Bronchoalveolar lavage fluid nucleic acid detection of Legionella (+).
Sputum culture report: Acinetobacter baumannii.
Diagnosis and Treatment
Diagnosis: severe pneumonia; type I respiratory failure; acute respiratory distress syndrome (ARDS); hypoalbuminemia.
Treatment: Mechanical ventilation, moxifloxacin + piperacillin sodium tazobactam sodium for anti-infection, methylprednisolone sodium succinate for injection to reduce exudation wait for treatment.
After comprehensive treatment, re-examination of chest CT showed that the consolidation of the right lower lobe was better than before, and the double pneumonia was more advanced than before. After that, the patient’s condition gradually improved. On the 20th day after entering the ICU, the patient’s condition was stable and transferred to the general ward.
Case analysis
This patient developed an out-of-hospital disease, was positive for Legionella urine antigen, and tested positive for nucleic acid in bronchoalveolar lavage fluid, confirming Legionella pneumonia.
The chest lesions showed complex and diverse appearances on CT: large patchy consolidation shadows, patchy fuzzy shadows, gauze shadows, and small nodular proliferation shadows with clear boundaries.
Legionella pneumonia has an acute onset, a dangerous condition and a high mortality rate. Clinicians should diagnose as soon as possible and give effective treatment.
Where can I learn more emergency knowledge?
What should I do if I encounter severe community-acquired pneumonia while on duty in the emergency department? Finding the cause is the most important! How to deal with emergencies correctly?
Severe allergic reaction rescue, is epinephrine the first choice? How is the drug administered? Where can I see the flow chart of the emergency meeting, the main points of treatment, and the most complete summary of emergency medicines?
More emergency cases
Take a look at the Decision Assistant “Daily Alert” module