Guest Author: Dr Jonathon Wills 2019
This is a big topic, which I have tried to divide up and cover as broadly as possible. I am only qualified in this by having done a few more than your average rural doctor, due to a previous life as a registrar in cardiothoracics. This hopefully draws together a number of guidelines with a rural focus. If there are any big gaps or contradicting evidence please comment below.
There is a one page summary as a separate document if you want the ‘cheat sheet’ version without the details.
Firstly, here is a summary of my interpretation of the evidence:
NON- TRAUMATIC CONDITIONS:
Obviously needs decompression immediately. This can be via finger thoracostomy or needle decompression. Physician choice as to which method, but the main consideration is timeliness.
There is some evidence that decompression in the midaxillary line, 2nd intercostal space often fails with standard cannulas due to chest wall thickness and that the anterior/midaxillary line, 5th intercostal space may be more reliable. Needle decompression needs to be followed by a drain.
Make a distinction between primary and secondary.
Evidence here is changing, it seems there has been some local work which is yet to be published, but the results favour more conservative management of primary pneumothorax in most instances. The recommendations here are based on the currently published literature, but watch this space.
Small (ie: less than 2cm at the hilum or 3cm at the apex) can probably be managed conservatively, and are probably safe to monitor out of hospital.
Large: (more than 2cm at the hilum or 3cm at the apex) may still be able to be managed conservatively in minimally symptomatic patients, but will resolve quicker with aspiration or drainage. Really big ones (ie; complete lung collapse) should have a percutaneous/Seldinger drain.
This evidence requires a little caution in the rural context where patient might not be able to get back to hospital quickly. I would have a lower threshold for small bore percutaneous/Seldinger drain and making sure no ongoing air leak (ie: the bubbling stops)
There are currently no good studies comparing needle aspiration to small bore saldinger drains (original studies were using large surgical drains and benefit was decreased admission rates plus length of stay.
Needle aspiration is likely to fail to resolve the pneumothorax with complete lung collapse and tends to fail about ⅓ of the time anyway., Likewise, if more than 2.5L of air is aspirated there is a high likelihood of ongoing leak, therefore these patients should have a drain.
BTS guidelines suggest ok to fly after full resolution, rather than a mandatory time-frame. If you work in a part of the world with loads of tourists this may be an indication to drain more frequently.
If there is a need for ongoing transfer, particularly air transport, consideration should be given to drainage prior.
My general philosophy is if I am going to intervene, I do so with a percutaneous drain, mainly because then I don’t have to stand there aspirating, but also because having punctured the pleura, it doesn’t take much to saldinger exchange for a drain.
diseased lung eg asthma, COPD e.t.c.
Due to the compromised underlying lung, these patients are less likely to be suitable for conservative management. Firstly smaller pneumothoraces cause more respiratory compromise due to less physiological reserve. Secondly, there is higher risk of ongoing air leak from diseased lung.
Small secondary pneumothoraces should be observed in hospital and large or symptomatic ones should be drained, needle aspiration has higher failure rates due to ongoing air leak.
Therefore, similar to treating primary spontaneous pneumothorax, if I am going to intervene (which is much more likely in secondary pneumothorax) I tend to put in a percutaneous drain.
Oxygen therapy; very old small human and animal studies show up to four fold increase in resorption with oxygen therapy. There is no recent or high quality evidence for this, particularly in light of growing evidence of harm from oxygen.
If your are draining the pneumothorax, short of treating hypoxia there is no point. When pneumothoraces are managed conservatively (and patient not hypoxic) I am not sure of the of the benefit to potential harm ratio.
Drain properly/dry; 50% will reaccumulate. They are likely to need repeat procedure earlier if just aspirated/incompletely drained. Clamp at 1.5L for 2 hours (see note below about re-expansion pulmonary oedema).
Consider early pleurodesis; talc is best agent. VATS (video assisted thoracic surgery) pleurodesis is probably the most effective method (95%), though talc slurry is almost as good (90%). Lung expansion needs to be confirmed first, as pleurodesis can’t be effective if the pleura aren’t in contact. In the rural setting, bedside talc pleurodesis is probably a reasonable therapy given similar success rates to VATS and it could be delivered locally.
Most malignant pleural effusions will reaccumulate. Therefore if survival more than a few months is predicted (LENT score is the only validated tool for this) more definitive management (ie pleurodesis talc slurry versus VATS procedure) or indwelling pulmonary catheter (particularly if lung trapped because pleurodesis very likely to fail if lung can’t re-expand) should be considered, though these procedures are likely to be unavailable at rural hospitals.
Re-expansion pulmonary oedema is a rare but nasty complication of pleural space drainage. Risk factors for re-expansion pulmonary oedema are younger age(20–40), duration of collapse longer than 1 week and volume greater than 3000mL. There is no real evidence for the arbitrary value of 1.5L, re-expansion pulmonary oedema has been reported at much lower volumes. In fact most of these risk factors seem to be very old and week evidence and the most recent case series suggests it doesn’t matter, (though they did use manometry to ensure no greater than –20cm intrapleural pressure). In this case fluid was removed manually via syringe- not by free drainage.
ie: either too small to sample, or a free-flowing small effusion has a neutrophilic exudate (an elevated protein level >0.5 percent of serum and/or a lactate dehydrogenase (LDH) level >0.6 that in the serum), a normal pH, a normal glucose level, and does not contain micro-organisms
Probably OK to leave alone and will resolve with appropriate treatment for pneumonia. Parapneumonic effusions that don’t meet above criteria are considered complicated and should be drained percutaneously.
Intra-pleural fibrinolysis can help based on a few small RCTs and is probably ok to do rurally as relatively low complication rates.,
Needs to be drained, small bore probably ok. Intrapleural fibrinolysis as above can reduce the need for surgery
Ultrasound guidance is good for drains is good. (Bedside of course); (0% vs 33% failure rate; 3% vs 18% pneumothorax).,
Should probably be drained based on current practise. There is very little data unless they are small.
ATLS convention says all traumatic pneumothoraces should be drained.
Occult traumatic pneumothoraces (those seen on CT but not plain X-ray can probably be managed conservatively (90% no significant deterioration), even those on positive pressure ventilation., (This is retrospective observational data and those treated conservatively had smaller pneumothoraces than those who were drained.) Those with concurrent haemo-pneumothorax were more likely to fail conservative management.
I can’t find any evidence about ‘occult pneumothoraces’ when diagnosed by ultrasound rather than CT- but maybe similar to ones on CT?
There is growing evidence towards smaller drains (open insertion) and percutaneous drains are probably OK based on very small trials.,
In the setting of chest tube placement for traumatic pneumothorax; antibiotics should be given to cover staph and strep (less pneumonia and empyema).
Three sided dressing appear out- they mostly don’t work. Recommendations are to occlude wound with a vented dressing if available, if not simply seal the wound with an occlusive dressing and monitor closely for signs of tension pneumothorax.
I am a little sceptical here, occlusive dressings seem unnecessarily risky. Did someone on the committee have shares in a specialised vented dressing?
Place chest tube through a clean site, close wound (simple dressing is fine initially, or formal closure provided that don’t meet indications for the formal operative thoracotomy)-
I can’t find any good evidence for this other than various brief statements in various trauma guidelines.
Drain it unless very small- retained blood in the pleural space is a problem; complication include empyema (up to 33%) or fibrosis impairing lung function.
However, there is some suggestion a more conservative approach is coming here too! However about ⅓ of those observed initially did require a drain. Four independent predictors of failed observation were identified: older age, fewer ventilation-free days, large hemothorax, concurrent pneumothorax.
Small drains are OK, Seldinger ones probably are too. It seems blood will come out fine through any sized tube, but clot won’t drain regardless of tube size.
INDICATIONS FOR SURGERY
therefore transfer to a cardiothoracic service if you haven’t already…
There is some retrospective evidence that a combined total of more than 1500 mL blood from a chest tube has higher mortality and this value can be used regardless of rate of accumulation. Beyond this most guidelines state: greater than 1500 mL total or more than 200mL/hr for 2–4 hours.
These should usually be drained as per haemothorax. Also, as above, pneumothoraces are more likely to require drainage if associated blood.
Having covered the covered the evidence, I cannot finish without a personal rant.…
Open tube thoracostomy (ie: surgical drain) is a very different procedure to percutaneous techniques (eg: Saldinger) and you need to have different considerations prior to procedure. I commonly see ideal locations for the two confused.
An open tube thoracostomy is a surgical procedure that requires safe access to the pleura.
Considerations for location of this procedure involves establishing safe passage through minimal tissue to the pleural space. Traditionally this is the ‘triangle of safety’ around the 4/5th intercostal space in the anterior/midaxillary line (though the 2nd intercostal space midclavicular line can also be used). Because the pleural space is entered by blunt dissection and then confirmed by palpation of the back of the ribs it does not matter if the lung is adjacent to the pleura, it will be safely pushed away by blunt objects as you enter the pleura. Therefore the location of an open tube thoracostomy is determined by safe access to the pleural space, NOT maximal point of pneumothorax or blood/fluid.
In contrary, a percutaneous technique involves using a sharp object to enter the pleural space. (Ultrasound guided of course) To enter the pleural space safely with a sharp object you need space between needle tip and lung. Therefore the best location for this procedure depends mainly on biggest space between visceral and parietal pleura. (though safe passage through the chest wall needs to also be considered, given it is a minimally invasive technique this is less important) Ultrasound guidance means in the setting of pleural fluid you can determine the best location based on a large space between pleural layers. (This will depend on patient position). In the setting of pneumothorax, ultrasound can only determine the pleura are not opposed, rather than the distance between them. Regardless, the same principle applies, you should be placing a saldinger drain only where there is a safe gap between parietal pleura and lung.
Finally when you are securing drains, please don’t spiral the tie up around it, the shortest distance around a cylinder is the circumference, not a spiral- a spiralled tie will slide down and come loose, it may look pretty but its not effective!