Brain protective effect of dexmedetomidine vs propofol for sedation during prolonged mechanical ventilation in non-brain injured patients

Table 1 Baseline characteristics of non-brain injured patients, n (%)

	Dexmedetomidine (n = 52)	Propofol (n = 63)	P value
Age (yr), median (IQR)	61.0 (55.0-64.0)	61.0 (53.0-66.0)	0.663
Male	30 (57.7)	39 (61.9)	0.646
BMI (kg/m2), median (IQR)	21.8 (19.6-24.3)	21.1 (19.0-22.3)	0.191
SAPS II, median (IQR)	46.0 (38.0-54.0)	46.0 (36.0-53.0)	0.675
Main reason for ICU
Medical	37 (71.2)	44 (69.9)	0.983
Surgical	10 (19.2)	13 (20.6)
Trauma	5 (9.6)	6 (9.5)
Infection at ICU admission	24 (46.2)	30 (47.6)	0.875
SOFA score of organ > 2
Respiratory	30 (57.7)	35 (55.6)	0.818
Cardiovascular	26 (50.0)	27 (42.9)	0.444
Renal	8 (15.4)	10 (15.9)	0.943
Coagulation	4 (7.7)	6 (9.5)	0.729
Liver	1 (1.9)	1 (1.6)	0.891
Total SOFA score, median (IQR)	7.0 (4.0-9.0)	6.0 (3.0-9.0)	0.954
RASS score at enrollment, median (IQR)	-2 (-3 to -1)	-3 (-3 to -1)	0.247
Time from ICU admission to drug initiation (h), median (IQR)	32.0 (20.0-35.0)	31.0 (20.0-42.0)	0.798

ICU: Intensive care unit.

Table 2 Dosage of study drugs during mechanical ventilation

	Dexmedetomidine (n = 52)	Propofol (n = 63)	P value
Duration of study drug infusion (h), median (IQR)	52.0 (36.0-73.5)	53.0 (37.0-72.0)	0.958
Dose of study drug (μg or mg/kg/h), median (IQR)	0.58 (0.34-0.79)	0.82 (0.65-1.32)	-
Dose of remifentanil (μg/kg/h), median (IQR)	4.5 (4.0-5.0)	4.6 (4.0-5.0)	0.395
Receiving rescue sedation, n (%)	36.0 (69.2)	32.0 (50.8)	0.045

Table 3 Comparison of sedative effect between the two groups

	Dexmedetomidine (n = 52)	Propofol (n = 63)	P value
Percentage of time within the target RASS (%), median (IQR)	85.6 (65.8-96.6)	86.7 (72.3-95.3)	0.592
Percentage of target RASS score (%), median (IQR)	72.2 (60.8-91.7)	73.3 (60.0-100.0)	0.880

RASS: Richmond Agitation and Sedation Scale.

Table 4 Comparison of S100-β serum levels between the two groups

Time	Dexmedetomidine		Propofol		P value
	n	S100-β	n	S100-β
Day 0	52	0.12 (0.06-0.18)	63	0.14 (0.08-0.23)	0.4080
Day 1	52	2.12 (2.03-2.22)	63	3.02 (2.92-3.18)	< 0.001
Day 2	52	2.30 (2.18-2.48)	63	3.53 (3.32-3.85)	< 0.001
Day 3	52	2.88 (2.67-3.05)	63	3.62 (3.39-4.06)	< 0.001
Day 4	35	3.58 (3.36-3.85)	40	4.70 (4.35-4.97)	< 0.001
Day 5	22	4.46 (4.34-4.58)	28	4.98 (4.86-5.44)	< 0.001
Day 6	15	4.83 (4.68-5.03)	19	5.33 (4.98-5.65)	0.0026
Day 7	10	5.06 (4.81-5.32)	14	5.38 (5.19-5.67)	0.0562

Table 5 Comparison of neuron-specific enolase serum levels between the two groups

Time	Dexmedetomidine		Propofol		P value
	n	NSE	n	NSE
Day 0	52	9.95 (9.08-10.65)	63	9.86 (9.35-10.56)	0.9570
Day 1	52	20.09 (17.63-21.43)	63	21.42 (20.71-23.08)	< 0.001
Day 2	52	20.35 (17.96-21.50)	63	22.35 (21.38-23.92)	< 0.001
Day 3	52	24.89 (21.87-26.85)	63	26.25 (25.15-27.35)	< 0.001
Day 4	35	26.62 (23.43-29.35)	40	29.17 (26.61-31.14)	0.0082
Day 5	22	26.75 (24.93-29.37)	28	29.66 (27.72-31.14)	0.0047
Day 6	15	28.93 (26.35-30.52)	19	30.72 (28.65-31.98)	0.0774
Day 7	10	28.34 (26.95-31.23)	14	30.54 (28.90-32.46)	0.2060

NSE: Neuron-specific enolase.