Head of bed (HOB) elevation to 30° after severe traumatic brain injury (TBI) has become standard positioning across all age groups. This maneuver is thought to minimize the risk of elevated ICP in the hopes of decreasing cerebral blood and fluid volume and increasing cerebral venous outflow with improvement in jugular venous drainage. However, HOB elevation is based on adult population data due to a current paucity of pediatric TBI studies regarding HOB management. In this prospective study of pediatric patients with severe TBI, the authors investigated the role of different head positions on intracranial pressure (ICP), cerebral perfusion pressure (CPP), and cerebral venous outflow through the internal jugular veins (IJVs) on postinjury days 2 and 3 because these time periods are considered the peak risk for intracranial hypertension.
Patients younger than 18 years with a Glasgow Coma Scale score ≤ 8 after severe TBI were prospectively recruited at a single quaternary pediatric intensive care unit. All patients had an ICP monitor placed, and no other neurosurgical procedure was performed. On the 2nd and 3rd days postinjury, the degree of HOB elevation was varied between 0° (head-flat or horizontal), 10°, 20°, 30°, 40°, and 50° while ICP, CPP, and bilateral IJV blood flows were recorded.
Eighteen pediatric patients with severe TBI were analyzed. On each postinjury day, 13 of the 18 patients had at least 1 optimal HOB position (the position that simultaneously demonstrated the lowest ICP and the highest CPP). Six patients on each postinjury day had 30° as the optimal HOB position, with only 2 being the same patient on both postinjury days. On postinjury day 2, 3 patients had more than 1 optimal HOB position, while 5 patients did not have an optimal position. On postinjury day 3, 2 patients had more than 1 optimal HOB position while 5 patients did not have an optimal position. Interestingly, 0° (head-flat or horizontal) was the optimal HOB position in 2 patients on postinjury day 2 and 3 patients on postinjury day 3. The optimal HOB position demonstrated lower right IJV blood flow than a nonoptimal position on both postinjury days 2 (p = 0.0023) and 3 (p = 0.0033). There was no significant difference between optimal and nonoptimal HOB positions in the left IJV blood flow.
In pediatric patients with severe TBI, the authors demonstrated that the optimal HOB position (which decreases ICP and improves CPP) is not always at 30°. Instead, the optimal HOB should be individualized for each pediatric TBI patient on a daily basis.