In vitro norepinephrine significantly activates isolated platelets from healthy volunteers and critically ill patients following severe traumatic brain injury

Table 3 Changes in laboratory and clinical variables following severe traumatic brain injury

	First week	Second week	P value
Laboratory values
Platelets, × 10³/μL	150 ± 6	215 ± 10^a	<0.001
Lowest values	128 ± 14; day 1
Highest values		224 ± 23; day 14
Leukocytes, × 10³/μL	8.7 ± 0.4	12.3 ± 1^a	<0.01
C-reactive protein, mg/L	121 ± 26	133 ± 23	NS
Interleukin-6, ng/L	142 ± 40	78 ± 21	NS
Calculated arterio-jugular venous differences
AJVD platelets, × 10³/μL	1.5 ± 0.9	5.8 ± 2^a	<0.01
AJVD leukocytes, × 10³/μL	-0.12±0.05	-0.02±0.1^a	<0.03
AJVD glucose, mM	0.33 ± 0.02	0.43 ± 0.04^a	<0.04
AJVD lactate, mM	-0.03±0.006	-0.06±0.01^a	<0.04
AJVD sP-selectin, pg/mL	454 ± 932	700 ± 1,254	NS
Neuromonitoring
Mean arterial pressure, mm Hg	97 ± 1	96 ± 1	NS
Intracranial pressure, mm Hg	13 ± 0.7	16 ± 0.5^a	0.019
Cerebral perfusion pressure, mm Hg	83 ± 1	80 ± 1	NS
SjvO₂, percentage	76 ± 1	69 ± 1^a	<0.001
Temperature, °C	36.2 ± 0.1	35.5 ± 0.1^a	<0.001
Pharmacologic treatment/platelet transfusions
Norepinephrine, μg/minute	7 ± 0.64	7.2 ± 1.03	NS
Fentanyl, mg/hour	0.6 ± 0.05	0.59 ± 0.08	NS
Midazolam, mg/hour	62 ± 5	59 ± 8	NS
Platelet transfusions, ml	300 ± 227 (n = 4)	0
HES 130/0.4, mL (Voluven^®
Cumulative	11,935 ± 1,826^a	3,000 ± 2,100	<0.001
Daily average	1,571 ± 260^a	429 ± 300	<0.001

Positive arterio-jugular venous differences (AJVDs) reflect cerebral uptake, while negative AJVD values unmask release or decreased uptake/binding. Values are expressed as mean ± standard error of the mean. ^aDifferences are rated significant at the corresponding levels of significance using the t test or Mann-Whitney test, respectively. a, significant differences; HES, hydroxyethyl starch; NS, not significant; SjvO₂, jugular venous oxygen saturation.

ISSN: 1364-8535