hey everybody this is rishi and in this video i wanted to talk about the terms pneumothorax and collapsed lung now in everyday conversation with a non-medical person a non-medical person will use the term collapse lung to mean pneumothorax but as medical professionals we should really try to aim for more precise language and not use the term collapse lung when we really mean pneumothorax let's define the terms collapse lung and pneumothorax real quick i'm sure you've heard of the term atelectasis which means loss of aeration of the lung due to caving in of the air spaces remember that atelectasis is different from consolidation because in consolidation the air spaces are filled with something like pneumonia or pulmonary edema in the case of atelectasis the air spaces aren't filled in with anything they're just caved in like a deflated balloon collapsed lung is just another name for complete atelectasis of the lung and we can also talk about a collapsed lobe which means a whole lobe is adolectatic pneumothorax on the other hand just means air in the plural space between the visceral and parietal pleura it doesn't tell us anything about the state of aeration of the lung these terms are mutually exclusive from one another meaning you can have a collapsed lung with or without a pneumothorax and you can have a pneumothorax with or without a collapsed lung i think the confusion arises because if we take this normal chest x-ray and imagine that the visceral pleura goes this way meaning the lung collapses how could you not have a pneumothorax in that space and i just want to show you a couple examples of how that can happen in this case we have complete opacification of the left hemithorax and we have a bronchial cutoff sign right here and that's because this patient had a mucous plug causing collapse of their left lung because of the fact that the mediastinum is shifted towards the side of the opacity we can say with a pretty high degree of confidence that this is isolated collapse of the lung without a significant pleural effusion so in this case the mediastinum is located about right here and the rest of that space in the left hemithorax is occupied by the collapsed lung so this is a case of a collapsed lung without a pneumothorax and instead of air taking up that space in the pleura we have the mediastinum taking up the space that was once occupied by the aerated left lung let's take a look at another case in this case we have another complete white out but notice that the trachea is shifted to the contralateral side of the opacification that tells us that not only do we have lung collapse here but we also have a large pleural effusion and although we can't see the delineation between the pleural fluid and the lung i would guess that the lung is collapsed around the hilum something like this and we don't even see any air bronchograms in it so it's really hard to tell and that the rest of this opacity is due to pleural fluid so again we have a case of complete collapse of one lung but instead of a pneumothorax we have a large pleural effusion taking up the space of the once aerated lung now here's a case in which we have a pneumothorax and we have near complete collapse of the right lung so this right here is the visceral pleura and you can see that the lung is almost completely collapsed with just a little bit of aerated lung over here and down here however most pneumothoraxes do not look like this example this is also a case of a pneumothorax you can see the thin visceral pleural line here but the lung is still about 90 percent or more aerated and no would call this a collapsed lung all right to summarize i showed you two cases of a collapsed lung that are not from a pneumothorax one was from a mucous plug and the second was due to a large pleural effusion and i also showed you two cases of pneumothorax one with a collapsed lung and one without a collapsed lung i hope this clears up any confusion you might have about these terms but if you still have questions you can leave them in the comments section below thanks