Comparative efficacy of different doses of dexmedetomidine in sedation during awake fibreoptic nasotracheal intubation: A systematic review and meta-analysis

Abstract

Background and aims: Awake fibreoptic nasotracheal intubation (AFONI) is critical in patients with difficult airways, requiring effective sedation that preserves spontaneous ventilation and airway reflexes. This systematic review evaluated the comparative efficacy of various dexmedetomidine doses in sedation for AFONI, with a meta-analysis focusing on 0.5, 1, and 1.5 µg/kg doses.

Methods: Databases searched included PubMed, EMBASE, Web of Science, and Cochrane, initially up to 5 May 2024, with a top-up search on 15 April 2025. Five studies were systematically reviewed, covering dexmedetomidine doses of 0.5, 0.7, 1, 1.5, and 2 µg/kg. A meta-analysis was conducted on two studies with doses of 1 and 1.5 µg/kg, and two studies with doses of 0.5 and 1.5 µg/kg. Primary outcomes included patient comfort, intubation scores, and sedation levels; secondary outcomes included vocal cord function, cough, and limb movements. Continuous and dichotomous outcome variables were summarised as mean difference and risk ratio, with a 95% confidence interval, using RStudio 2024.12.0 (PROSPERO ID: CRD42024541481).

Results: Meta-analysis showed that 1.5 µg/kg did not significantly improve patient comfort or intubation conditions compared to 1 and 0.5 µg/kg. No significant differences were observed in intubation comfort scores, sedation levels, or patient satisfaction across the various doses.

Conclusions: Dexmedetomidine at 0.5 and 1 µg/kg offers effective sedation and patient comfort comparable to 1.5 µg/kg during AFONI. Given the very low to moderate certainty of evidence, further large-scale studies are warranted to establish optimal dosing for enhanced patient experience and reduced side effects across various clinical settings.

Keywords: Airway; awake intubation; conscious sedation; dexmedetomidine; doses; intubation; patient comfort; patient satisfaction; systematic review.

Figure 1

Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) flow diagram

Figure 2

Forest plot showing the pooled relative risk of no reaction in comfort score between dexmedetomidine 1.5 µg/kg and dexmedetomidine 1 µg/kg group. RR=Risk Ratio, CI=Confidence Interval, Dex=Dexmedetomidine

Figure 3

Forest plot showing the pooled relative risk of no reaction in comfort score between dexmedetomidine 1.5 µg/kg and dexmedetomidine 0.5 µg/kg group RR=Risk Ratio, CI=Confidence Interval, Dex=Dexmedetomidine

Figure 4

Forest plot showing the pooled relative risk of slight grimacing in comfort score between dexmedetomidine 1.5 µg/kg and dexmedetomidine 1 µg/kg group. RR=Risk Ratio, CI=Confidence Interval, Dex=Dexmedetomidine

Figure 5

Forest plot showing the pooled relative risk of slight grimacing in comfort score between dexmedetomidine 1.5 µg/kg and dexmedetomidine 0.5 µg/kg group. RR=Risk Ratio, CI=Confidence Interval, Dex=Dexmedetomidine

Figure 6

Forest plot showing the pooled relative risk of defensive movement in comfort score between Dexmedetomidine 1.5 µg/kg and Dexmedetomidine 1 µg/kg group. RR=Risk Ratio, CI=Confidence Interval, Dex=Dexmedetomidine

Figure 7

Forest plot showing the pooled relative risk of defensive movement in comfort score between dexmedetomidine 1.5 µg/kg and dexmedetomidine 0.5 µg/kg group. RR=Risk Ratio, CI=Confidence Interval, Dex=Dexmedetomidine

Figure 8

Forest plot showing the pooled mean difference of sedation scores between dexmedetomidine 1.5 µg/kg and dexmedetomidine 1 µg/kg group. SMD=Standardised Mean Difference, CI=Confidence Interval, Dex=Dexmedetomidine

Figure 9

Forest plot showing the pooled relative risk of good satisfaction score between Dexmedetomidine 1.5 µg/kg and Dexmedetomidine 1 µg/kg group. RR=Risk Ratio, CI=Confidence Interval, Dex=Dexmedetomidine

Figure 10

Forest plot showing the pooled relative risk of good satisfaction score between dexmedetomidine 1.5 µg/kg and dexmedetomidine 0.5 µg/kg group. RR=Risk Ratio, CI=Confidence Interval, Dex=Dexmedetomidin

Figure 11

Forest plot showing the pooled relative risk of fair satisfaction score between dexmedetomidine 1.5 µg/kg and dexmedetomidine 1 µg/kg group. RR=Risk Ratio, CI=Confidence Interval, Dex=Dexmedetomidine

Figure 12

Forest plot showing the pooled relative risk of fair satisfaction score between dexmedetomidine 1.5 µg/kg and dexmedetomidine 0.5 µg/kg group. RR=Risk Ratio, CI=Confidence Interval, Dex=Dexmedetomidine

Figure 13

Forest plot showing the pooled relative risk of poor satisfaction score between dexmedetomidine 1.5 µg/kg and dexmedetomidine 1 µg/kg group. RR=Risk Ratio, CI=Confidence Interval, Dex=Dexmedetomidine

Figure 14

Forest plot showing the pooled relative risk of poor satisfaction score between dexmedetomidine 1.5 µg/kg and dexmedetomidine 0.5 µg/kg group. RR=Risk Ratio, CI=Confidence Interval, Dex=Dexmedetomidine

Figure 15

Risk-of-bias assessment for studies comparing the outcomes between dexmedetomidine 1.5 µg/kg and dexmedetomidine 1 µg/kg. ROB2 – (a) Traffic light plot; (b) Summary plot. (a) Quality assessment of the risk of bias in the included trials. The traffic light plot presents a schematic representation of risks (low=green, some concerns=yellow) for specific types of biases of each study in the review. (b) Quality assessment of the risk of bias in the included trials. The summary plot presents risks (low=green, some concerns=yellow) for the subtypes of biases of the combination of studies included in this review

Figure 16

Risk-of-bias assessment for studies comparing the outcomes between dexmedetomidine 1.5 µg/kg and dexmedetomidine 0.5 µg/kg. ROB2 – (a) Traffic light plot; (b) Summary plot. (a) Quality assessment of the risk of bias in the included trials. The traffic light plot presents a schematic representation of risks (low=green, some concerns=yellow, and high=red) for specific types of biases of each study in the review. (b) Quality assessment of the risk of bias in the included trials. The summary plot presents risks (low=green, some concerns=yellow, and high=red) for the subtypes of biases of the combination of studies included in this review