Q&A: Hospital-acquired Pneumonia (Nosocomial Pneumonia)

Hospital-acquired pneumonia (HAP) or nosocomial pneumonia refers to any pneumonia contracted by a patient in a hospital at least 48–72 hours after being admitted. It is thus distinguished from community-acquired pneumonia. It is usually caused by a bacterial infection, rather than a virus.

This article is for Medical Students & Professionals

This is a  Question & Answer revision article designed for medical students and professionals preparing for the PLAB, MRCP or USMLE examinations. They are based on actual questions from these examinations. You may find the Pneumonia article more useful, or one of our many articles on Diseases & Conditions, Medical Syndromes, Health & Wellness or Home Remedies.

In this article:
What is nosocomial pneumonia?
MCQ exam: clinical scenario
MCQ exam: answer
MCQ exam: explanation

What is nosocomial pneumonia?

Hospital-acquired pneumonia (HAP), also known as nosocomial pneumonia, is defined by the American Thoracic Society guidelines as pneumonias that occur more than 48 hours after hospital administration but was not present at the time of admission.

Nosocomial pneumonia is one of the leading entities of nosocomial infections worldwide with invasive ventilation being one of the major risk factors. Major general risk factors include old age, multi-morbidity, preexisting pulmonary disease, immunosuppression and abdominal or thoracic surgery.

Evidence based prevention measures for ventilated patients include hand hygiene, aseptic handling techniques of the ventilator circuit, subglottic suctioning for patients intubated more than 72 hours, cuff pressure control, mouth and dental care, daily spontaneous breathing trials, use of sedation protocols and head of bed 30-45 degrees. For non-ventilated patients early mobilization and/or frequent position changes, correct use of feeding tubes and mouth care are key components. In preoperative patients training of a simple breathing exercise combined with mnemonic aids for its use in the postoperative period has been proven to be helpful.

MCQ exam: clinical scenario

Hospitalized immunocompromised patients are at risk for pneumonias.

Which of the following would represent such a nosocomial pneumonia?

a) P carinii
b) Nocardia spp
c) M avium-intracellulare
d) Pseudomonas aeruginosa
e) Staphylococcus aureus

MCQ exam: answer

The correct answer is D.
Pseudomonas aeruginosa is a common cause of nosocomial pneumonia.

MCQ exam: explanation

Hospitalized immunocompromised patients are at risk for nosocomial pneumonias, half of which are caused by anaerobic gram-negative bacilli, including:

• Pseudomonas aeruginosa,
• Enterobacter species,
• Klebsiella species,
• Escherichia coli, and
• Acinetobacter specie

A hospital-acquired infection (HAI), also known as a nosocomial infection, is any infection that is acquired in a hospital or other health care facility. This includes pneumonia. To emphasize both hospital and nonhospital settings, it is sometimes instead called a healthcare–associated infection (HAI or HCAI), therefore you could also have a healthcare–associated pneumonia. Such an infection can be acquired in hospital, nursing home, rehabilitation facility, outpatient clinic, diagnostic laboratory or other clinical settings.

Reference(s)
1). National Library of Medicine: Nosocomial pneumonia. Dtsch Med Wochenschr. 2020 Mar;145(6):371-382. doi: 10.1055/a-0993-1078. Epub 2020 Mar 19. Available online: https://pubmed.ncbi.nlm.nih.gov/32191977/
2). Radiopaedia: Hospital-acquired pneumonia. Available online: https://radiopaedia.org/articles/hospital-acquired-pneumonia-1
3). Wikipedia, the Free Encyclopedia: Hospital-acquired pneumonia. Available online: https://en.wikipedia.org/wiki/Hospital-acquired_pneumonia