Deciphering Arterial Line Waves

[offlabel]

Above is the arterial wave form of an awake,  non intubated patient. Below represents the arterial wave form of that patient intubated.

Explain.

(The actual pressures are irrelevant.)

[offlabel]

Mods, can you move this to Student Nurse Anesthetists?

[allnurses Admin Team]

Topic moved to SRNA forum.

[chare]

Not a CRNA/SRNA, but I'll give it a shot.

The non-intubated a-line tracing represents an extreme example of pulsus paradoxus.  Being intubated and mechanically ventilated results in an elevated intrathoracic pressure and diastolic pressure; decreasing the pulsus paradoxis.

[offlabel]

chare said:

Not a CRNA/SRNA, but I'll give it a shot.

The non-intubated a-line tracing represents an extreme example of pulsus paradoxus.  Being intubated and mechanically ventilated results in an elevated intrathoracic pressure and diastolic pressure; decreasing the pulsus paradoxis.

Nice, Chare....maybe some SRNA's could learn something from you! So, you've identified that positive pressure ventilation must change the filling because the peaks and valleys of the tracing have vanished. But that's kind of counter intuitive because positive pressure reduces venous return. 

We know that, when breathing spontaneously, RV filling increases on inspiration, but the valleys on that tracing are on...inspiration! Why?

Maybe some students can demonstrate they're smart enough for anesthesia school?