Table 3.

Cerebral hemodynamics pre- and post L-arginine administration at 12 and 48 hours post-injury (the “Worst” side is the hemisphere with the most severe traumatic injury).

Variable: Side	12 hr Post-injury		48 hr Post-injury		P value

	Pre-LA mean (SD)	Post-LA mean (SD)	Pre-LA mean (SD)	Post-LA mean (SD)	Day	L-Arg	Day x L-Arg	Day x L-Arg x Injury side	Other Factor

ICA-Fvol: Worst	184 (70)	189 (59)	181 (51)	210 (65) ^†	0.1559	0.0190	0.0045	0.7247
Best	185 (58)	195 (54)	175 (49)	214 (75) ^†

ICA-FV: Worst	57 (15)	61 (17)	72 (19) ^*	74 (20)	<0.0001	0.0968	0.6725	0.7641	Age 0.0456
Best	59 (17)	61 (18)	72 (20) ^*	74 (19)

ACA-FV: Worst	50 (15)	55 (15)	60 (19) ^*	64 (16)	<0.0001	0.0029	0.5667	0.6599
Best	50 (15)	54 (16)	63 (21) ^*	69 (22)

MCA-FV: Worst	69 (28)	72 (25)	91 (55) ^*	93 (27)	<0.0001	0.1886	0.9722	0.5384
Best	70 (21)	73 (25)	87 (25) ^*	94 (26)

PCA-FV: Worst	53 (16)	57 (19)	69 (22) ^*	72 (23)	<0.0001	0.0597	0.8388	0.6763
Best	53 (15)	57 (18)	71 (23) ^*	72 (26)

ARI: Worst	2.18 (1.37)	2.45(1.94)	1.82 (1.24)	2.04 (1.78)	0.1204	0.0738	0.8783	0.8175	Age 0.0414
Best	2.01 (1.44)	2.14 (1.63)	1.74 (1.43)	1.98 (1.62)

THRR: Worst	1.13 (0.15)	1.14 (0.15)	1.13 (0.13)	1.13 (0.11)	0.8057	0.1713	0.5540	0.6124
Best	1.19 (0.14)	1.16 (0.17)	1.16 (0.17)	1.12 (0.12)

CO₂R: Worst	2.2 (1.5)	3.0 (1.8)	2.5 (1.5)	3.3 (2.1)	0.1520	0.0002	0.1595	0.1880
Best	2.1 (1.3)	3.4 (2.1)	2.4 (1.8)	2.9 (1.9)

pre-L-arginine value at 48hr is different from pre-L-arginine value at 12hr (p<.05)

^†

change with L-arginine infusion at 48hr is different from change with L-arginine infusion at 12hr (p<.05)

Abbreviations: LA = L-arginine infusion

L-Arg: effect = of L-arginine administration

ACA = anterior cerebral artery

MCA = middle cerebral artery

PCA = posterior cerebral artery

F Vol = flow volume

FV = flow velocity

ARI = autoregulation index

THRR = transient hyperemic response ratio

CO₂R = carbon dioxide reactivity