The Crashing Vented Patient (Critical Care Mini-fellowship Summary)

Author: Taylor Douglas, Raymond Beyda

Edited by: Robby Allen

You’re on a tough CCT shift, and you’ve just walked your junior resident through a complicated intubation, and she was successful. You’re congratulating yourselves behind the desk while ordering the confirmatory chest x-ray when the nurse comes to you and says, “Hey Doc, the patient doesn’t look so good.” Your attending is out buying everyone celebratory coffees, so you enter the trauma bay alone to find out what went wrong.

You start by looking at the whole patient-ventilator circuit and asking yourself some important questions:

How are they breathing? Are they in distress?

Are they awake, alert, anxious, diaphoretic?

Is blood pressure dropping? Is the heart rate rising? Is oxygen saturation dropping?

Do the waveforms on the ventilator indicate the problem?

Ventilator waveforms (courtesy of Deranged Physiology [1])

As you start to feel overwhelmed, you remember with confidence that you went to the CCMF meeting earlier this year and learned a couple great mnemonics to assess (DOPES) and treat (DOTTS) the unstable intubated patient. [2]

The DOPES Mnemonic, an approach to the differential diagnosis of the crashing intubated patient.

D = Dislodgement

Has the tube moved?
Is there gurgling or bubbling at the oropharynx?

O = Obstruction

Is the patient biting the tube? Do they need more sedation or analgesia?
Has the tube kinked?
Could there be mucus plugging and blood clots?
On the vent waveform, this will be reflected by a high peak pressure but normal plateau pressure pointing to an airway resistance issue

High vs. normal airway resistance (Deranged Physiology, [3])

P = Pneumothorax

Is there asymmetry in chest rise? Are there equal breath sounds?
Grab your ultrasound! This is the time to look for that “beach sign.”

E = Equipment

Is the ventilator circuit broken or disconnected? Is it on?
Examine the tubing from the patient all the way to the wall.

S = Stacked Breaths

Is there chest rise? Are they very tympanic? Are the peak pressures very high?
Look at the flow time scalar. Is the flow returning to baseline? If not, there is likely auto-PEEP pathophysiology.

Normal flow and gas trapping (Deranged Physiology [4]). The first cycle shows a low peak expiratory flow and a prolonged expiratory phase. In the second cycle, the flow did not reach zero at the beginning of the next breath; gas trapping has occurred.

The DOTTS Mnemonic, an approach to treating potential causes for instability in the intubated patient.

D = Disconnect

Do this yourself. Don’t wait for respiratory. Then you can assess the patient (look, listen, and feel) while you bag them.
This removes all equipment failures from the equation besides the tube itself (and the BVM).

O = Oxygenate

Crashing patients with dropping O2 saturations or BP should receive 100% FiO2. You can down-titrate later, but give them all the oxygen you can while you’re troubleshooting.
Again, ventilation should be with BVM unless you are sure your equipment is not the problem.

T = Tube

You can use in-line suction and/or bougie to ensure the tube is patent.
You can always grab VL or DL to confirm the tube is properly placed and hasn’t been dislodged.
Have all your supplies available in case you need to re-intubate or perform a tube exchange.

T = Tweak

This is the point where we manage the breath-stacking patient.
Multiple options are available: decrease respiratory rate, decrease tidal volume, decrease inspiratory time (i time).
Decreasing respiratory rate is the most high-yield and should be your first modification.

S = Sonogram

The opportunity to use your POCUS skills arrives!
Look for pneumothorax, B-lines.
Consider using ultrasound as an adjust to confirm tube placement in the crashing patient. [5,6]
If their hemodynamic instability seems unrelated to their vent, consider a RUSH exam to look for other etiologies.

You walk back out of the trauma bay with confidence, having stabilized your patient just as your attending returns with some piping hot deli coffee. You call the ICU for admission and endorse your patient to their team for further care. You know you’ll be able to handle unstable intubated patients as long as you remember to diagnose with DOPES and treat with DOTTS.

References

1. Yartsev A. An introduction to the ventilator waveform. Deranged Physiology. Created 15 June 2015, Last updated 15 Sept 2018. Accessed 29 Sept 2020. https://derangedphysiology.com/main/cicm-primary-exam/required-reading/respiratory-system/Chapter%20551/introduction-ventilator-waveform

2. Rezaie S. REBEL Cast Ep 46b: Vent Management in the Crashing Patient with Haney Mallemat. REBEL EM blog. 12 Mar 2018. Accessed 12 Aug 2020. Available at: https://rebelem.com/rebel-cast-ep-46b-vent-management-crashing-patient-haney-mallemat/.

3. Yartsev A. Interpreting the shape of the pressure waveform. Deranged Physiology. Created 16 June 2015, Last updated 29 Sept 2019. Accessed 29 Sept 2020. https://derangedphysiology.com/main/cicm-primary-exam/required-reading/respiratory-system/Chapter%20552/interpreting-shape-pressure-waveform

4. Yartsev A. Interpreting the shape of the ventilator flow waveform. Deranged Physiology. Created 16 June 2015, Last updated 27 Sept 2018. Accessed 29 Sept 2020 https://derangedphysiology.com/main/cicm-primary-exam/required-reading/respiratory-system/Chapter%20553/interpreting-shape-ventilator

5. Chou HC, Tseng WP, Wang CH et al. Tracheal rapid ultrasound exam (T.R.U.E.) for confirming endotracheal tube placement during emergency intubation. Resuscitation. 2011;82(10):1279-1284. doi:10.1016/j.resuscitation.2011.05.016

6. Chao A, Gharahbaghian L. Tips and Tricks: Airway Ultrasound. ACEP Emergency Ultrasound Section website. Accessed 2 Oct 2020. https://www.acep.org/how-we-serve/sections/emergency-ultrasound/news/june-2015/tips-and-tricks-airway-ultrasound/

7. Pedigo R. Ventilator Management of Adult Patients in the Emergency Department. EM Practice, EB Medicine. 2020;22(7):1-20.

8. Owens W. Ventilator Management and Troubleshooting in the Emergency Department. EM Critical Care, EB Medicine. 2014;4(5):1-16.

9. Wood SL, Van der Kloot T. Ventilator Management in the Intubated Emergency Department Patient. EM Critical Care, EB Medicine 2013;3(4):1-16.