What is Lobar pneumonia?

Answer 1

Pneumonia is usally an infection or inflammation of the very smallest bits of our lungs - called alveoli. These are very small, very thin 'sacks' where oxygen can pass out of the air we breath and into our blood so we can do all the things we need to.

If a bacteria (or less commonly a virus) starts making a home for itself there, our bodies react by activating our immne system to try and destroy it. This means that lots of fluid floods into the area, showing up as white on a chest x-ray (what doctors call 'consolidation'). Obviously, if there's fluid here, the alveoli can't function to exchange oxygen, so the patient becomes short of breath and weak, and are usually in pain.

A lobar pnneumonia is usually only on one side, and affecting a whole 'lobe' (big chunk) of the lung. These patients will often also have fluid filling up the space OUTSIDE the lung, called a pleural effusion, which makes it even harder to breath. The bacteria often responsible for a lobar pneumonia is called pneumococcus, and we like to vaccinate the elderly against this as they're most at risk. The lungs of people with lobar pneumonia can fill up with nasty pus, so putting a chest drain in is sometimes also necessary. It's this nasty pus that people with a lobar pneumonia cough up, so these patients are often described as having a 'productive cough'.

The other type of bacterial pneumonia is called a bronchopneumonia, which unlike the lobar-type, tends to affect both lungs, and rather than affecting a whole lobe, shows up little patches like cotton-wool on the x-ray. You usually don't see the pleural effusion that you might with a lobar pneumonia. The bacteria that are often responsible for causing bronchopneumonia include Streptococcus pneumoniae, Staphlococcus aureus, Pseudomonas aeroginosa or Haemophilus influenzae.

Knowing the type is important, as it will often inform the choice of immediate treatment. Sputum (the stuff you cough up) can be sent to lab for the pathologists to smear onto jelly and see what grows. This means you can be prescribed the best antibiotic!