Ventilating the Patient with Traumatic Brain Injury

• Many patients with acute TBI will require intubation and mechanical ventilation for a variety of reasons.
• Ventilating the patient with TBI becomes a balancing act between maintaining adequate cerebral perfusion and minimizing lung injury.
• Some pearls to consider:
  • Avoid hypoxia: although guidelines recommend a P_aO₂ > 60 mm Hg, most suggest a higher P_aO₂ (> 80 mm Hg) be initially targeted.
  • Avoid hypercapnia:  many patients will develop hypercapnia when ventilated using the low tidal volume strategy (6 ml/kg) of the ARDSnet trial; titrate TVs to maintain a P_aCO₂ between 32-35 mm Hg.
  • PEEP: the application of PEEP remains controversial in patients with TBI given the theoretical risk of increasing ICP through reductions in venous return; if PEEP is applied pay close attention to the cerebral perfusion pressure to ensure it remains > 60 mm Hg.

References

Young N, Rhodes JKJ, Mascia L, Andrews PJD. Ventilatory strategies for patients with acute brain injury. Curr Opin Crit Care 2010; 16:45-52