Optimal Effect-Site Concentration of Propofol for Hemodynamic Stability During Intubation with Dexmedetomidine: A Randomized Controlled Study

Abstract

Background: This study aimed to determine the 95% effective concentration (EC₉₅) of propofol via target-controlled infusion (TCI) for endotracheal intubation at three different doses of dexmedetomidine.

Methods: One hundred and eighty patients aged 18-60 and classified as American Society of Anesthesiologists (ASA) class I-II were enrolled to undergo general anesthesia. Patients were randomly assigned to one of the three groups (A, B, or C), receiving three different doses of dexmedetomidine (0.6, 0.8, or 1 μg/kg) infused over 10 min. Anesthesia was then induced with propofol TCI, followed by rocuronium. The biased coin design method was used to calculate the EC₉₅ of propofol for successful intubation. The primary outcome endpoint was the EC₉₅ of propofol for successful endotracheal intubation at each dexmedetomidine dose.

Results: Sixty patients in each group completed the trial. The time from propofol administration to intubation in group C (132.5 ± 10.7 s) was significantly shorter compared to group A (140.2 ± 14.4 s, P<0.0001) and group B (142.6 ± 13.2 s, P=0.0037). Both the EC₉₅ and the average total dose of propofol in group B [14.6 (10.8, 14.8) μg/mL and 3.6 ± 1.1 mg/kg] and C [12.7 (11.5, 12.8) μg/mL and 2.8 ± 1.0 mg/kg] were lower than those in group A [14.9 (4.5, 15.0) μg/mL and 3.8 ± 0.9 mg/kg] (P<0.001). The incidence of hypotension and bradycardia during induction was low in each group.

Conclusion: The EC₉₅ of propofol for endotracheal intubation across three different background doses of dexmedetomidine was determined. We suggest administering 1.0 μg/kg dexmedetomidine and then the EC₉₅ of propofol for successful endotracheal intubation was 12.7 μg/mL.

Registration: Chinese Clinical Trial Registry; Registration number: ChiCTR2400089952, URL:https://www.chictr.org.cn/showproj.html?proj=221236.

Keywords: dexmedetomidine; effective concentration; endotracheal intubation; opioid-free anesthesia; propofol.

Figure 1

Flowchart of the study.

Figure 2

(A-C) The positive or negative reaction for each participant at the designated dosage of dexmedetomidine, with the participant sequence on the x-axis and each allocated dosage on the y-axis, respectively.

Figure 3

The HR (A), MAP (B), and BIS (C) values at T₀, T₁, T₂, T₃, T_4, and T₅ in three groups. T₀: before administering dexmedetomidine, T₁: before anesthesia induction, T₂: before tracheal intubation, T₃: during tracheal intubation, T₄: after tracheal intubation, T₅: 3 minutes after tracheal intubation. No significant differences (P>0.05) in HR, MAP and BIS values were observed at these time points in the three groups.