Analgesia for spinal anesthesia positioning in elderly patients with proximal femoral fractures: Dexmedetomidine-ketamine versus dexmedetomidine-fentanyl

Abstract

Elderly patients with femoral fractures are anticipated to endure the most pain caused by positional changes required for spinal anesthesia. To improve pain relief, we compared the analgesic effects of intravenous dexmedetomidine-ketamine and dexmedetomidine-fentanyl combinations to facilitate patient positioning for spinal anesthesia in elderly patients with proximal femoral fractures. Forty-six patients were randomly assigned to two groups and received either 1 mg/kg of intravenous ketamine (group K) or 1 μg/kg of intravenous fentanyl (group F) concomitant with a loading dose of dexmedetomidine 1 μg/kg over 10 minutes, then dexmedetomidine infusion only was continued at 0.6 μg/kg/h for following 20 minutes, and titrated at a rate of 0.2 to 0.6 μg/kg/h until the end of surgery. After completion of the infusion of either ketamine or fentanyl, the patients were placed in the lateral position with the fracture site up. The pain score (0 = calm, 1 = facial grimacing, 2 = moaning, 3 = screaming, and 4 = unable to proceed because of restlessness or agitation) was used to describe the pain intensity in each step during the procedure (lateral positioning, hip flexion, and lumbar puncture), and quality score (0 = poor hip flexion, 1 = satisfactory hip flexion, 2 = good hip flexion, and 3 = optimal hip flexion) was used to describe the quality of posture. Group K showed a median pain score of 0 (0-1), 0 (0-0) and 0 (0-0) in lateral positioning, hip flexion and lumbar puncture, respectively, while group F showed a score of 3 (2.75-3), 3 (2-3) and 0 (0-1), respectively. The pain score in lateral positioning (P < .0001) and hip flexion (P < .0001) was significantly lower in group K than group F. Group K showed the significantly higher quality scores of spinal anesthesia positioning (P = .0044) than group F. Hemodynamic adverse effects, such as bradycardia, hypotension, and desaturation, were not significantly different between the groups. The administration of dexmedetomidine-ketamine showed a greater advantage in reducing pain intensity and increasing the quality with patient positioning during spinal anesthesia in elderly patients with proximal femoral fractures, without any serious adverse effects.

Conflict of interest statement

The authors have no conflicts of interest to disclose.

Figures

Figure 1

CONSORT flow diagram.

Figure 2

Infusion plan. Intravenous ketamine (1 mg/kg) or fentanyl (1 μg/kg) was infused, concomitant with a loading dose of dexmedetomidine 1 μg/kg over 10 minutes. Then ketamine or fentanyl infusion was discontinued, and the infusion of dexmedetomidine was continued at 0.6 μg/kg/h for the next 20 min, and then titrated at a rate of 0.2–0.6 μg/kg/h until the end of surgery. Group K = patients who received dexmedetomidine-ketamine, Group F = patients who received dexmedetomidine-fentanyl. T0: at the beginning of infusion, T10: 10 min later, T30: 30 minlater, T100: at the end of surgery.

Figure 3

Mean blood pressure (MBP) at a 5-minute interval during the first 30 min from the beginning of dexmedetomidine administration with either ketamine or fentanyl. Intravenous ketamine (1 mg/kg) or fentanyl (1 μg/kg) was infused, concomitant with a loading dose of dexmedetomidine 1 μg/kg over 10 min. Then ketamine or fentanyl infusion was discontinued, and the infusion of dexmedetomidine was continued at 0.6 μg/kg/h for the next 20 minutes. There was no statistically significant difference in the MBP between groups K and F. The MBP at T20, T25 and T30 were significantly lower than that at T0 in both groups. There were significant differences in the MBP between T10 and T15, and between T15 and T20 in group K, while significant differences were shown in the MBP between T10 and T15, between T15 and T20, and between T20 and T25 in group F. There was a significant decrease over time in each group (§: P < .001 in group K, #: P < .001 in group F). Data are presented as the mean ± SD. Group K = patients who received dexmedetomidine-ketamine, Group F = patients who received dexmedetomidine-fentanyl. †: P < .05 compared with baseline value, ‡: P < .05 compared with previous value.

Figure 4

Heart rate (HR) at a 5-minute interval during the first 30 min from the beginning of dexmedetomidine administration with either ketamine or fentanyl. Intravenous ketamine (1 mg/kg) or fentanyl (1 μg/kg) was infused, concomitant with a loading dose of dexmedetomidine 1 μg/kg over 10 minutes. Then ketamine or fentanyl infusion was discontinued, and the infusion of dexmedetomidine was continued at 0.6 μg/kg/h for the next 20 minutes. There was no statistically significant difference in the HR between groups K and F. The HR at T20, T25, and T30 were significantly lower than that at T0 in group K, while the HR at T15, T20, T25, and T30 were significantly lower than that at T0 in group F. There was a significant difference in the HR between T15 and T20 in group K, while there were significant differences between T10 and T15, and between T15 and T20 in group F. There was a significant decrease over time in each group (§: P < .001 in group K, #: P < .001 in group F). Data are presented as the mean ± SD. Group K = patients who received dexmedetomidine-ketamine, Group F = patients who received dexmedetomidine-fentanyl. †: P < .05 compared with baseline value, ‡: P < .05 compared with previous value.

Figure 5

Pulse oximetry saturation (SpO2) at a 5-min interval during the first 30 min from the beginning of dexmedetomidine administration with either ketamine or fentanyl. Intravenous ketamine (1 mg/kg) or fentanyl (1 μg/kg) was infused, concomitant with a loading dose of dexmedetomidine 1 μg/kg over 10 minutes. Then ketamine or fentanyl infusion was discontinued, and the infusion of dexmedetomidine was continued at 0.6 μg/kg/h for the next 20 minutes. There was no statistically significant difference in the SPO2 between groups K and F. Data are presented as the mean ± SD. Group K = patients who received dexmedetomidine-ketamine, Group F = patients who received dexmedetomidine-fentanyl.

Figure 6

Bispectral index (BIS) at a 5-min interval during the first 30 min from the beginning of dexmedetomidine administration with either ketamine or fentanyl. Intravenous ketamine (1 mg/kg) or fentanyl (1 μg/kg) was infused, concomitant with a loading dose of dexmedetomidine 1 μg/kg over 10 min. Then ketamine or fentanyl infusion was discontinued, and the infusion of dexmedetomidine was continued at 0.6 μg/kg/h for the next 20 minutes. The BIS at T15 was 82 ± 9 and 75 ± 14 in groups K and F, respectively, and there was a statistically significant difference between groups K and F (P = .0489). The BIS at T5, T10, T15, T20, T25, and T30 were significantly lower than those at T0 in both groups. There was a significant difference in the BIS between T0 and T5, and between T5 and T10 in group K, while there was a significant difference between T0 and T5 in group F. The BIS tended to decrease over time, and there was a significant decrease over time in both groups (§: P < .001 in group K, #: P < .001 in group F). Data are presented as the mean ± SD Group K = patients who received dexmedetomidine-ketamine, Group F = patients who received dexmedetomidine-fentanyl. ∗: P < .05 compared with group F, †: P < .05 compared with baseline value, ‡: P < .05 compared with previous value.