TABLE 3. Brain Tissue Po₂ Variables by Probe Position in 405 Patients With Long-term Neurological Outcome^a.

Variable	Probe in Normal Brain, Mean ± SD or Median (Interquartile Range)	Probe in Abnormal Brain, Mean ± SD or Median (Interquartile Range)	P
Patients, n	159	246
Average Pbto2	30.8 ± 18.2	25.6 ± 14.8	<.001
Pbto2 duration below thresholds, h
Time < 10 mm Hg	0 (0-6.0)	5 (0-23.0)	<.001
Time < 15 mm Hg	4.0 (0-20.8)	15 (3-43)	<.001
Time < 20 mm Hg	16 (2-36)	30 (9-58)	<.001
Pbto2 trend pattern	<.001
Always ≥ 10 mm Hg	108 (50.5)	106 (49.5)
Transiently < 10 mm Hg at start	42 (32.6)	87 (67.4)
Persistently < 10 mm Hg	2 (13.3)	13 (86.7)
Decreased to < 10 mm Hg after normal at start	7 (14.9)	40 (85.1)

^aPbto₂, brain tissue Po₂.