In which of the following situations should iatrogenic ...

[j.rubin]

In which of the following situations should iatrogenic hyperventilation be considered?
 
  a. Severe traumatic brain injury
  b. Initial treatment for increased intracranial pressure
  c. Acute head injuries with increased intra-cranial pressure
  d. Acute neurological deterioration with in-creased intracranial pressure

Question 2

Permissive hypercapnia could benefit patients with which of the following?
 
  a. Cerebral trauma
  b. Intracranial lesion
  c. Acute lung injury
  d. Cardiovascular instability

[sultansheikh]

Answer to Question 1

ANS: D
Hyperventilation may be needed for brief periods when acute neurological deterioration is pre-sent and the ICP is elevated. Current therapeutic guidelines for head injuries with increased ICP do not recommend prophylactic hyperventilation (PaCO2 < 25 mm Hg) during the first 24 hours. Hyperventilation during the first few days after severe traumatic brain injury (TBI) may actually increase cerebral ischemia and cause cerebral hypoxemia.

Answer to Question 2

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.