We covered how to wean patients from mechanical ventilation in our last post on extubation. In this post, we wanted to cover more advanced techniques, tips, and tricks to optimize your patient’s chances to safely come off mechanical ventilation.
The T-Piece is a device that you or your RT can attach to your patient’s endotracheal tube (ETT) that will allow them to oxygenate with the ETT in place, but remove the ventilatory support portion of mechanical intubation. Now the patient is breathing solely through the ETT without any PEEP or other ventilator support. Imagine that your patient is essentially breathing through a straw: most ETT are 7.5 – 8.0 mm in diameter! Your patient will have to work harder to pull adequate tidal volumes.
You may ask: why would this be of ANY benefit? What information could we get from putting the patient under MORE stress?
Good question! Let’s say that you had an 76 year old male with a history of heart failure with reduced ejection fraction who came in for a severe flash pulmonary edema and was intubated due to respiratory failure secondary to this. Prior to the flash episode, he had a severe increase in his blood pressure, from a baseline of 120/66 on his medication to 220/130.
It would make sense to try to make sure that the patient would not experience another episode of flash pulmonary edema, especially when the ETT is pulled out. The t-piece trial places your patient under a degree of stress (working harder to breath and overcome the increased airway resistance of the ETT). So in a situation like the previous example, if your patient gets hypertensive and tachycardic while undergoing a t-piece trial, it can indicate that they aren’t fully ready to be extubated.
On the other hand, if they sail through t-piece breathing without increasing their blood pressure or showing other signs of strain/stress, they may be safe to extubate.
Recently, the value of t-piece trials has been called into question. A recent RCT1 by Subira et al. showed that a short 30 min trial of pressure support at 8 cm H20 actually led to successful extubations more often than a two hour t-piece trial. Another study2 by Vallverdu et al. showed that most t-piece trials failed 30 minutes into the trial. I’ve worked with physicians who still use t-piece trials, but for shorter duration and only in patients who have severe heart failure, valve problems, or some risk of having flash pulmonary edema. To my knowledge, no criteria on when to use t-piece vs a short SBT with pressure support exists, but if one does, please share in the comments below!
Extubation to BiPAP
When would you ever consider putting someone directly onto a BiPAP after extubation? Didn’t the patient just have a lot of ventilatory support? Why would they need more?
I hear ya! It can be annoying to your patients to come off a breathing tube and go right to BiPAP, but there is excellent data that suggests this can prevent re-intubation, particularly in patients who presented with a severe COPD exacerbation. A small RCT3 done by Ornico et al. showed that, in patients who had been intubated for over 72 hours, immediately placing them on BiPAP after extubation significantly reduced the reintubation rate after 48 hours. They kept their patients on BiPAP for 24 hours, but to my knowledge there hasn’t been a study to determine optimal BiPAP timing yet (if you know of one, please let me know!)
The Tracheostomy Discussion
Despite our best efforts, sometimes a patient’s lung pathology is so severe that they are not able to wean safely off the vent in a relatively short time period. The longer the ETT remains in place, the more chance of developing ventilator acquired pneumonia, tracheomalacia, or other ETT induced complications. After about 10 days of ETT mechanical ventilation and consistently failed extubation trials, it may be time to have the conversation about offering a tracheostomy to your patient or patient’s family4. Obviously, different patients have different circumstances or different expectations with regard to the tracheostomy, but the highlights are that it can allow for safer long term weaning off mechanical ventilation.
The Debrief – Sunil’s Tips for Extubation:
1) Listen to the respiratory therapist! A good RT is an ESSENTIAL part of the ICU team, and you must incorporate their input into your rounds. They have the best knowledge of the patient’s respiratory status. Check in with the RT often – If the RT is worried, you should be worried too!
2) Dry lungs are happy lungs5! Try to keep your patient’s fluid balance net negative in the ICU. This is especially true if the primary reason for your patient’s respiratory failure was due to pulmonary edema.
3) 30 minutes of SBT on pressure support is PROBABLY enough for you to make a determination about your patient’s readiness to be extubated.
4) Every clinician will have their own recipe for judging readiness for extubation. Listen and learn from everyone, and then find a method that works for you.
5) LISTEN TO THE RESPIRATORY THERAPISTS!
Please share your tips and tricks for successful extubation below, or send me a message and I’ll add your suggestions! FOAMed works best when multiple people contribute knowledge!
- Subirà C, Hernández G, Vázquez A, et al. Effect of Pressure Support vs T-Piece Ventilation Strategies During Spontaneous Breathing Trials on Successful Extubation Among Patients Receiving Mechanical Ventilation: A Randomized Clinical Trial. JAMA. 2019;321(22):2175–2182. doi:10.1001/jama.2019.7234
- Vallverdú I, Calaf N, Subirana M, Net A, Benito S, Mancebo J. Clinical characteristics, respiratory functional parameters, and outcome of a two-hour T-piece trial in patients weaning from mechanical ventilation. Am J Respir Crit Care Med. 1998;158(6):1855-1862. doi:10.1164/ajrccm.158.6.9712135
- Ornico SR, Lobo SM, Sanches HS, et al. Noninvasive ventilation immediately after extubation improves weaning outcome after acute respiratory failure: a randomized controlled trial. Crit Care. 2013;17(2):R39. Published 2013 Mar 4. doi:10.1186/cc12549
- Bice T, Nelson JE, Carson SS. To Trach or Not to Trach: Uncertainty in the Care of the Chronically Critically Ill. Semin Respir Crit Care Med. 2015;36(6):851-858. doi:10.1055/s-0035-1564872
- Mekontso Dessap A, Roche-Campo F, Kouatchet A, Tomicic V, Beduneau G, Sonneville R, Cabello B, Jaber S, Azoulay E, Castanares-Zapatero D, Devaquet J, Lellouche F, Katsahian S, Brochard L. Natriuretic peptide-driven fluid management during ventilator weaning: a randomized controlled trial. Am J Respir Crit Care Med. 2012 Dec 15;186(12):1256-63. doi: 10.1164/rccm.201205-0939OC. Epub 2012 Sep 20. PMID: 22997204.
The increase in preload and afterload due to elimination of PEEP contributes to postextubation flash pulmonary edema and extubation failure, I pretreat patients who appear susceptible to post extubation flash with nitro paste just prior to extubation to prevent the increase in preload and afterload and subsequent flash.
Thank you for sharing! What a neat technique- I have not seen that done but that sounds interesting! I’ll have to give that a try!
Very interesting technique Michael. That makes sense. Thanks for sharing.