Author Question: A 63-year-old, 5'11, 185 lb male patient with a history of chronic obstructive pulmonary disease ... (Read 98 times)

joe · **on:** Jul 16, 2018

A 63-year-old, 5'11, 185 lb male patient with a history of chronic obstructive pulmonary disease (COPD) is admitted to the hospital due to liver failure. Over the course of the 48 hours he has developed respiratory distress.

The respiratory therapist performs a physical assessment and finds the following: heart rate 135 beats/min, respiratory rate 28 with accessory muscle use. Breath sounds are decreased bilaterally with coarse crackles in the right base. A chest X-ray from 24 hours ago shows bilateral lower lobe infiltrates. The patient has a nonproductive cough. The respiratory therapist draws an arterial blood gas that reveals: pH 7.31; partial pressure of carbon dioxide (PaCO2) 57 mm Hg; partial pressure of oxygen (PaO2) 58 mm Hg; arterial oxygen saturation (SaO2) 87; bicarbonate (HCO3) 27 mEq/L while receiving oxygen via nasal cannula 3 L/min. The respiratory therapist should recommend which of the following for this patient?
a. Continue with current therapy and moni-tor the patient closely.
b. Place the patient on a nonrebreather mask with 15 L/min oxygen.
c. Intubate and place on pressure-controlled continuous mandatory ventilation (PC-CMV), peak inspiratory pressure (PIP) 40 cm H2O, positive end-expiratory pressure (PEEP) 8 cm water (H2O), frac-tional inspired oxygen (FIO2) 1.0.
d. Use BiPAP with IPAP 10 cm H2O, EPAP 5 cm H2O, and bleed in 4 L/min oxygen.

Question 2

A 47-year-old, 6'1 male patient is admitted to the hospital due to trauma from a motor vehicle accident. Forty-eight hours post admission, the patient is suffering from respiratory distress with severe hypoxemia and is intubated.

A chest X-ray, done prior to intubation, reveals a ground glass appearance bilaterally. The physi-cian requests the volume-controlled continuous mandatory ventilation (VC-CMV) mode for this patient. The initial settings for the ventilator should be which of the following?
a. VT = 450 mL, rate = 18 breaths/min, PEEP = 8 cm H2O
b. VT = 600 mL, rate = 10 breaths/min, PEEP = 5 cm H2O
c. VT = 750 mL, rate = 15 breaths/min, PEEP = 10 cm H2O
d. VT = 900 mL, rate = 12 breaths/min, PEEP = 5 cm H2O

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

Answer to Question 1

ANS: D
This patient is showing signs of ventilatory failure as evidenced by his acute-on-chronic respira-tory acidosis with uncorrected hypoxemia. This patient should be tried on noninvasive positive pressure ventilation (NPPV) prior to intubation to try to avoid it if possible. Using a nonrebreath-er mask would not address the patient's ventilatory problem and may cause oxygen-induced hypoventilation. Continuing with current therapy would not address the problem of impending ventilatory failure. If intubated and mechanically ventilated with pressure-controlled continuous mandatory ventilation (PC-CMV), starting off at 40 cm H2O is too high. When the peak inspira-tory pressure (PIP) or plateau pressure (Pplateau) from volume ventilation are not available, an initial pressure of 10-15 cm H2O should be set followed by volume measurements and pressure adjust-ments when appropriate.

Answer to Question 2

ANS: A
First calculate ideal body weight (IBW) for a male, using the formula 106 + 6(ht 60). This pa-tient's IBW is 84 kg. Minute ventilation is about 100 mL/kg IBW, which would be 8.4 L/min. Since the patient appears to have acute respiratory distress syndrome (ARDS) the tidal volume should be set to between 4 and 6 mL/kg. This would make the appropriate tidal volume range 336-504 mL. This eliminates all of the choices except A. Dividing the tidal volume range into 8.4 L/min gives the set rate range at 17-25 breaths/min. This also eliminates all but choice A.