med 610 clinical respiratory diseases & critcare med

Mechanical Ventilation

Case 5 Answers

A 65 year-old man was admitted to the ICU with pneumonia and was intubated when he developed progressive hypoxemia. He has been on the ventilator for 5 days and has generally been tolerating this therapy well. The nurse calls you because he has all of a sudden become severely agitated and appears to be fighting the ventilator. She asks if she can increase the infusion rates on his midazolam and fentanyl drips for sedation.

What should you do next?

This patient has suddenly become agitated while breathing on the ventilator. In some cases, the agitation is due to inadequate sedation. In many other cases, however, there is a new potentially serious problem that has developed. The problem, however, may not be obvious because the patient is intubated and, therefore, cannot talk to you and tell you what is wrong. It is important to consider and exclude such problems, particularly when there is an acute change in the patient’s status. Some important items to consider on the differential diagnosis include a pneumothorax, mucous plug in the endotracheal tube, myocardial infarction, pulmonary embolism, unrecognized disconnection from the ventilator or other ventilator problem, auto-PEEP (hyperinflation and increased intrathoracic pressure) causing difficulty triggering the ventilator, worsening oxygenation and delirium. The first step in the evaluation is to disconnect the patient from the ventilator and manually ventilate (“bag”) them. If they improve, the problem is proximal to the endotracheal tube (i.e. the machine or the ventilator tubing). If they are still having problems the airways should be suctioned and a thorough assessment (some history, exam, ABG, CXR and possibly an EKG and laboratory studies) should be performed. Further testing such as a CT pulmonary angiogram might be warranted based on what you find on your initial evaluation. You should always consider the differential diagnosis noted above and exclude life threatening issues before assuming the problem is inadequate sedation.

Case Index>>

Top of Page