Author Question: Which of the following are valid reasons for not using a heat and moisture exchanger in infants? ... (Read 89 times)

mynx · **on:** Jul 16, 2018

Which of the following are valid reasons for not using a heat and moisture exchanger in infants?

1. Heat and moisture exchangers add 30 mL to 90 mL of mechanical dead space.
2. Heat and moisture exchangers are not effective with uncuffed endotracheal tubes.
3. Heat and moisture exchangers might cause an obstruction in endotracheal tubes in infants.
4. Heat and moisture exchangers are an inexpensive alternative to humidifiers.
a. 1, 2, and 3 c. 2 and 4
b. 1 and 4 d. 3 and 4

Question 2

A heat and moisture exchanger is best placed where in the ventilator circuit?

a. Directly at the patient Y-connector
b. Twenty centimeters away from the endo-tracheal tube
c. At the ventilator outlet
d. At the ventilator inlet

tuwy · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

ANS: A
Heat and moisture exchangers are not recommended for use in infants for several reasons. Heat and moisture exchangers add 30 to 90 mL of mechanical dead space, often exceeding the tidal volume of a 5-kg infant (i.e., 25 mL). Uncuffed endotracheal tubes used in infants allow a por-tion of exhaled gas to leak around the tube, bypassing the heat and moisture exchanger and re-ducing its ability to capture exhaled heat and humidity. Providing heated humidity at less than 35 C has been associated with narrowing and obstruction of endotracheal tubes in infants. The advantages of heat and moisture exchangers are that they are inexpensive alternatives to humidi-fiers and they are the best choice for adult patients.

Answer to Question 2

ANS: A
Heat and moisture exchangers should be placed directly at the airway or patient Y-connector. Other heat and moisture exchanger locations that might also prove effective are 10 cm away from the endotracheal tube.