Tracheal tube with pressure monitoring lumen and method for using the same
According to various embodiments, methods and systems for determining pressure in the lungs may employ tracheal pressure measurements. The tracheal pressure measurements may be obtained through a pressure monitoring lumen associated with a tracheal tube. Such systems may include a purging or flushing mechanism to keep the pressure monitoring lumen free of any obstructions. The flushing mechanism may utilize fluids delivered through the pressure monitoring lumen at a predetermined point in the breathing cycle and/or at a predetermined pressure relative to the respiratory gases. The resulting pressure measurements may be used to determine a more accurate estimate of lung pressure, which in turn may be used to control a ventilator and provide breathing assistance to a patient.
1. A method comprising:
measuring a tracheal pressure of a patient's trachea with a pressure transducer in fluid communication with a pressure monitoring lumen, wherein the pressure monitoring lumen is associated with a tracheal tube;
receiving information related to a respiratory gas pressure over a breathing cycle of a patient;
determining a baseline pressure associated with a minimum pressure point over the course of the breathing cycle of the patient;
delivering a purging fluid as a bolus of purging fluid timed to coincide with the minimum pressure point over the course of the breathing cycle of the patient through the pressure monitoring lumen at a purging pressure greater than the respiratory gas pressure; and
determining a corrected tracheal pressure of the patient's trachea that accounts for the bolus of purging fluid based at least in part on the baseline pressure, wherein determining the corrected tracheal pressure comprises substituting the measured pressure during the bolus delivery with the baseline pressure.
2. The method of claim 1 , further comprising determining a second corrected tracheal pressure at a different point over the course of the breathing cycle based on a difference between a purging pressure and the tracheal pressure of the patient's trachea.
3. The method of claim 1 , comprising determining the baseline pressure in the pressure monitoring lumen at exhalation and using the baseline pressure to determine the corrected tracheal pressure.
4. The method of claim 3 , wherein the baseline pressure is a pressure left in the lungs after an end of exhalation.
5. The method of claim 1 , wherein delivering the purging fluid is controlled by instructions encoded within a processor.
6. The method of claim 1 , further comprising determining a second corrected tracheal pressure at a different point over the course of the breathing cycle by subtracting a purging pressure from the pressure in the pressure monitoring lumen.