Author Question: A 57-year-old, 5'3, 165 lb female patient arrives in the open heart unit following coronary artery ... (Read 27 times)

chads108 · **on:** Jul 16, 2018

A 57-year-old, 5'3, 165 lb female patient arrives in the open heart unit following coronary artery bypass surgery.

The patient has a history of diabetes and no history of pulmonary disease. The most appropriate initial volume-controlled continuous mandatory ventilation (VC-CMV) settings are which of the following?
a. VT = 220 mL, rate = 25 breaths/min, PEEP = 10 cm H2O
b. VT = 360 mL, rate = 15 breaths/min, PEEP = 5 cm H2O
c. VT = 550 mL, rate = 12 breaths/min, PEEP = 12 cm H2O
d. VT = 750 mL, rate = 10 breaths/min, PEEP = 8 cm H2O

Question 2

A 5'2 female patient with normal lungs has been intubated and requires mechanical ventilation with volume-controlled continuous mandatory ventilation (VC-CMV).

The tidal volume (VT) and ventilator rate settings that should be recommended for this patient are which of the following?
a. VT = 315 mL, rate = 20 breaths/min
b. VT = 364 mL, rate = 14 breaths/min
c. VT = 468 mL, rate = 12 breaths/min
d. VT = 563 mL, rate = 10 breaths/min

anoriega3 · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

ANS: B
First calculate ideal body weight (IBW) for a female, using the formula 105 + 5(ht 60). This patient's IBW is 55 kg. Minute ventilation is about 100 mL/kg IBW, which would be 5.54 L/min. Since the patient is post-op, the tidal volume should be set to between 5 and 8 mL/kg with rates of between 10 and 20 breaths/min. This would make the appropriate tidal volume range 275-440 mL. This fact eliminates choices A, C, and D. The positive end-expiratory pressure (PEEP) may also be too high for a post-op open heart patient in choices A, C, and D.

Answer to Question 2

ANS: B
First calculate ideal body weight (IBW) for a female, which is 105 + 5(ht 60) = 52 kg. Then using the range of 5-7 mL/kg IBW the tidal volume range for this patient is 260-364 mL. Minute ventilation is about 100 mL/kg IBW. Therefore, minute ventilation should be approximately 5.2 L/min. Then dividing the calculated minute ventilation by the tidal volume range for this patient provides a range of rates for the tidal volumes: 14-20 breaths/min depending on the set volumes. The most appropriate volume and rate combination for this patient is 364 mL 14 breaths/min = 5.1 L/min.