Permissive hypercapnia could benefit patients with which of the following?

a. Cerebral trauma
b. Intracranial lesion
c. Acute lung injury
d. Cardiovascular instability

ANS: C
Patients with ALI benefit from permissive hypercapnia to protect the lungs from ventila-tor-induced lung injury. Contraindications to PHY include cerebral disorders, because CO2 is a powerful vasodilator. PHY is also contraindicated in patients with preexisting cardiovascular in-stability, because the circulatory effects of PHY can include decreased myocardial contractility, arrhythmias, vasodilation, and increased sympathetic activity.