Effects of dexmedetomidine sedation on cerebral blood flow and cerebral oxygen metabolism in patients with acute craniocerebral injury

Zhifeng LU; Yanping WU; Jie GAO

ABSTRACT

Objective:

To observe the sedative effect of dexmedetomidine(DEX) on patients with acute craniocerebral injury(ACI), and to explore its influences on cerebral blood flow(CBF) and cerebral oxygen metabolism.

Methods:

A total of 68 ACI patients were randomly divided into control group( n=34) and observation group( n=34) according the random digital table method.The patients in both two groups were transferred to intensive care unit(ICU) for routine comprehensive treatment after surgery.On this basis, the observation group was given intravenous injection of 0.5 μg·kg -1·h -1 DEX for 3d.The changes of mean arterial pressure(MAP), heart rate(HR), respiration rate(RR), blood oxygen saturation(SpO 2), scores of Ramsay and Glasgow Coma Scale(GCS), CBF, jugular bulb venous oxygen saturation(SjvO 2), arteriovenous oxygen content difference(AVDO 2) and cerebral oxygen extraction rate(CERO 2) were compared between the two groups.

Results:

At 24h and 72h after being transferred to ICU, MAP[(89.05±10.91)mmHg, (90.24±9.40)mmHg], HR[(82.42±9.51)times/min, (81.18±8.26)times/min] and RR[(27.03±5.20)times/min, (26.38±4.75)times/min] in the observation group were significantly lower than those in the control group[(109.49±10.41)mmHg, (103.63±11.68)mmHg, (109.52±8.37)times/min, (104.46±9.16)times/min, (32.76±5.71)times/min, (29.59±4.40)times/min]( t=7.904, 5.208, 12.473, 11.006, 4.326, 2.891, all P<0.05). There was no statistically significant difference in SpO 2 between the two groups( P>0.05). At 72h, the Ramsay score in the observation group was lower than that in the control group[(2.72±0.35)points vs.(3.42±0.40)points], while the GCS score was higher than that in control group[(11.92±1.81)points vs.(10.14±2.28)points], and there were statistically significant differences between the two groups( t=7.679, 3.565, all P<0.05). At 72h, the CBF, AVDO 2 and CERO 2 were lower than those at 0h in the observation group( t=2.406, 4.908, 6.291, all P<0.05), which were significantly lower than those in the control group( t=2.087, 5.493, 6.423, all P<0.05). At 72h, the SjvO 2 was higher than that at 0h in the observation group[(61.27±4.70)% vs.(51.44±3.48)%]( t=9.801, P<0.05), which was significantly higher than that in the control group[(53.32±3.64)%]( t=7.798, P<0.05).

Conclusion:

DEX can improve postoperative sedation effect of ACI patients, stabilize vital signs, reduce cerebral oxygen consumption and improve cerebral oxygen metabolism disorders.