Tasty Morsels of Critical Care 054 | Chest injuries
Welcome back to the tasty morsels of critical care podcast. This time round we’re going to have a look at some chest wall injuries you should know about. The main reference here is Oh’s manual chapter 79. The vast majority of what we see here is going to be simple pneumothoraces and the elderly patient with some rib fractures and contusions or a developing pneumonia. That kind of thing is our bread and butter. This post will focus on some of the more esoteric injuries which of course occur with disproportionate frequency in fellowship examinations. There are a fairly small number of immediately life threatening injuries we need to recognise and the list could include: * tension PTX * open/sucking PTX * massive haemothorax * pericardial tamponade Massive haemothorax is typically defined as >1500mls immediately or more than 200ml/hr is certainly a concern that should prompt a surgeon to have a look inside. While not mentioned in Oh, the main concern with these is a sort of “damned if you do, damned if you don’t” scenario. When presented with a massive haemothorax and hypotension, it is not always immediately clear what the primary physiology causing the hypotension is. For example a large haemothorax with tension physiology will kink the SVC and obstruct the IVC leading to hypotension due to low preload to the heart. They may also be hypotensive form frank hypovolaemia because all the blood is in the pleural cavity instead of the blood vessels. The bit you can’t account for is how much this tension phenomenon is actually providing some kind of tamponade effect and keeping the remaining intravascular volume in the vasculature. The concern here is that when you decompress the haemothorax the patient is no less hypovolaemic than they were before. The blood is now in the chest drain rather than the pleural space. This hasn’t really fixed the hypovolaemia but has relieved the tension phenomenon obstructing the preload to the heart. Unfortunately it may have also unleashed the remaining circulating volume to enter the pleural cavity and swiftly out through the plastic conduit you’ve placed and into the chest drain. All this is a very long and convoluted way to say that it’s complicated. I think we will always end up draining that massive haemothorax but it would be wise to have someone capable of dealing with major bleeding inside the chest, immediately on hand. Speaking of thoracotomies, what follows is a list of interventions that might be potentially useful to do once the chest is open. * drain pericardial tamponade, this is 1st, 2nd and 3rd for me in terms of importance and utility. * control intrathoracic bleeding – which is a nice coverall term for all the various bits blood could be squirting out of * control of massive broncho venous embolism. In this scenario a pulmonary vein is lacerated and air is being entrained into the left side of the heart. This is bad form as one might imagine so it would be wise to clamp it * control of massive bronchopleural fistula. Maybe a lung has been avulsed proximally and you can see the ET tube through the bronchus. All the Vt is disappearing into the pleural space and you should something to stop it * temporary blocking of the aorta. Commonly done in an attempt to preserve the circulating volume to the heart and brain. You might better achieve this without opening the chest with a REBOA or a SAAP catheter but that’s a whole different kettle of fish * internal cardiac massage. In terms of aortic injuries these are often fatal pre-hospital but if you do find one they’ll typically be at the junction of the fixed and tethered aorta and the slightly more mobile arch. This junction occurs at the isthmus just distal to the ta...