Airway Dimensions in Children with Neurological Disabilities During Dexmedetomidine and Propofol Sedation for Magnetic Resonance Imaging Study

Abstract

Objective: Children with neurological disabilities are at an increased risk of airway complications during anaesthesia for magnetic resonance imaging (MRI) with spontaneous respiration. The primary objective of this study was to evaluate airway dimensions during propofol and dexmedetomidine sedation for MRI in children with neurological disabilities. The secondary objective was to examine the adverse respiratory and sedation-related events.

Methods: Seventy-two children aged 1-6 years undergoing MRI were randomly selected to receive sedation with either 2 mg kg-1 h-1 of propofol or 2 μg kg-1 h-1 of dexmedetomidine. The airway dimensions were measured at soft palate, the base of tongue and mid-epiglottis. Adverse airway events were noted, and the quality of sedation was determined based on the need for dose modification, patient movement and repeat imaging requirements.

Results: There was no significant difference in airway dimensions observed between the dexmedetomidine and propofol groups, except for maximum and minimum transverse diameter (15.4±3.4 vs. 13.4±4.7, p=0.04 and 14.6±3.3 vs. 12.4±4.7, p=0.02 respectively) at soft palate and for cross sectional area difference at the base of tongue (14.5±13.9 vs. 20.1±19.3, p=0.03). Airway obstruction (2/36 vs. 3/36), apnoea (0/36 vs. 3/36) and desaturation (0/36 vs 2/36) occurred less frequently with dexmedetomidine. Additional requirement of sedation (6 vs. 3 patients; p=0.48), movement during imaging (9 vs. 5 patients; p=0.37) and poor image quality necessitating re-acquisition (4 vs. 0 patients; p=0.08) were more frequent with propofol.

Conclusion: Airway dimensions were similar during dexmedetomidine and propofol sedation, except for the transverse diameters at soft palate, and for cross-sectional area difference at the base of tongue in spontaneously breathing children with neurological disabilities. Airway complications were less frequent and the quality of sedation was better with dexmedetomidine.

Keywords: Airway; children; dexmedetomidine; magnetic resonance imaging; propofol.

Conflict of interest statement

Conflict of Interest: No conflict of interest was declared by the authors.

Figures

Figure 1

Flow diagram showing participation of patients in the study

Figure 2

Sagittal view of MRI of the upper airway showing three levels of image acquisition at soft palate, base of the tongue and mid-level of epiglottis during dexmedetomidine infusion

Figure 3

Airway dimensions at the mid-level of epiglottis in a child with dexmedetomidine sedation (Upper left and lower left: Antero-posterior minimum and maximum diameter. Upper middle and lower middle: Transverse minimum and maximum diameter. Upper right and lower right: Minimum and maximum cross-sectional area)

Figure 4

Airway dimensions at the base of tongue level in a child with dexmedetomidine sedation (Upper left and lower left: Antero-posterior minimum and maximum diameter. Upper middle and lower middle: Transverse minimum and maximum diameter. Upper right and lower right: Minimum and maximum cross-sectional area)

Figure 5

Airway dimensions at the soft palate level in a child with dexmedetomidine sedation (Upper left and lower left: Antero-posterior minimum and maximum diameter. Upper middle and lower middle: Transverse minimum and maximum diameter. Upper right and lower right: Minimum and maximum cross-sectional area)

Figure 6

Changes in the heart rate over time in the dexmedetomidine and propofol groups

Figure 7

Changes in the systolic blood pressure over time in the dexmedetomidine and propofol groups