UMEM Educational Pearls

Title: Mechanical Ventilation Strategies in Paralyzed or Sedated Patients

Keywords: Mechanical Ventilation, Paralytics (PubMed Search)

Posted: 4/27/2019 by Mark Sutherland, MD (Updated: 11/13/2024)
Click here to contact Mark Sutherland, MD

Many, if not nearly all, of our intubated patients in the ED have altered mental status, a potential to clinically worsen, or a requirement for medications that would alter their respiratory status (e.g. propofol, opioids, paralytics). It is imperative to place these patients on appropriate ventilator modes to avoid apnea when their respiratory status changes.

Spontaneous modes (see partial list below) REQUIRE patients to initiate breaths on their own. No ventilation occurs in a true spontaneous mode without patient effort.
Patients who have alterations in respiratory drive, neuromuscular function, or are receiving paralytics should NOT be placed on:
- Pressure Support (PSV),
- Volume Support (VSV),
- CPAP/BiPAP/APAP,
- Pressure-Assisted Ventilation (PAV) / Proportional Pressure Support (PPS),
- or other spontaneous modes
Our hypothermia order set includes a prn paralytic (cisatracurium infusion, vecuronium bolus) to combat shivering. Discontinue these medications for patients on spontaneous modes.
Our Servo-I ventilators automatically backup to a control mode (VS-->VC, PS-->PC) after a period of apnea (default is anywhere from 15-45 seconds, but it depends on how the RT has set the ventilator) as a safety mechanism, but this could still cause dangerous hypoxia or hypercapnea in severely ill patients.
If the mechanics of pressure support are desired in patients at risk of apnea, there are other methods to achieve this (PC, descending flow VC, SIMV VC+PS with a low rate, and others).
Always consult your RT when changing ventilator settings, and be sure to take vent alarms seriously.

References

Marx, J. A., & Rosen, P. (2014). Rosen's emergency medicine: concepts and clinical practice. 8th ed. Philadelphia, PA: Elsevier/Saunders. Chapter 2 Mechanical Ventilation and Non-Invasive Ventilatory Support.
Servo I User Manual: https://www.medonegroup.com/pdf/manuals/userManuals/Maquet-Servo-i-Operators-Manual.pdf. Accessed 4/27/2019.

Attachments

1904271657_Apnea_Alarm.JPG (16 Kb)