A hemodynamically unstable patient being ventilated in the volume-controlled continuous mandatory ventilation (VC-CMV)mode is triggering inspiration at a rate of 25 breaths/min and has the following arterial blood gas results: pH 7.50,partial pressure of carbon dioxide (PₐCO₂)30 mm Hg,partial pressure of oxygen (PₐO₂)98 mm Hg,arterial oxygen saturation (SₐO₂)100%,bicarbonate (HCO₃⁻)24 mEq/L.The respiratory therapist should perform which of the following?
A) Extubate and administer noninvasive positive pressure ventilation (NIV).
B) Change the mode to pressure-controlled continuous mandatory ventilation (PC-CMV).
C) Change the mode to volume-controlled intermittent mandatory ventilation (VC-IMV).
D) Sedate and paralyze the patient.

Question

Quizplus · Accepted Answer

This patient has ventilator-induced hyperventilation as evidenced by the partial pressure of carbon dioxide (PₐCO₂)of 30 mm Hg with a trigger rate of 25 breaths/min.Switching to the volume-controlled intermittent mandatory ventilation (VC-IMV)mode will decrease the number of ventilator breaths the patient triggers by allowing the patient to breathe spontaneously between the mandatory ventilator breaths.This will reduce the patient's minute ventilation and normalize the PₐCO₂ and pH.Another potential advantage is to put less of a strain on an already hemodynamically unstable patient.There is nothing in this patient's scenario that suggests extubation and use of noninvasive positive pressure ventilation (NIV).Switching to the pressure-controlled continuous mandatory ventilation (PC-CMV)mode will most likely not correct the patient's problem because the patient will still be able to trigger ventilator set breaths and could continue to hyperventilate.Although sedating and medically paralyzing the patient could normalize the patient's acid-base balance,it is not the treatment of choice because of the hemodynamic instability of the patient.

A Hemodynamically Unstable Patient Being Ventilated in the Volume-Controlled Continuous