Effect of a neck collar on upper airway size in children sedated with propofol-midazolam combination during magnetic resonance imaging

Airway patency in children undergoing magnetic resonance imaging using neck collars: a single center, randomized, double-blind, prospective study

Background and objectives

Maneuvers precluding the downward shift of the mandibula and providing slight extension of the head have been shown to increase upper airway dimensions. This study aimed to investigate the role of Neck Collars (NC) in maintaining airway patency during Magnetic Resonance Imaging (MRI) examination in a pediatric population aged between 0 and 16 years.

Methods

One hundred twenty-five children were recruited in this prospective study. Subjects were randomly assigned to NC group (NC+) or standard imaging group (NC-). Measurements of anteroposterior and transverse dimensions and cross-sectional area were performed to determine the upper airway size at three distinct levels: soft palate, base of the tongue, and tip of the epiglottis.

Results

The anteroposterior diameter and cross-sectional area at the levels of base of the tongue and soft palate were significantly higher in NC+ patients compared to NC- patients. However, anteroposterior dimensions and cross-sectional areas at the epiglottis level were similar in the two groups. When patients were analyzed according to age groups of 0–2, 2–8, and 8–16 years, the anteroposterior diameter and cross-sectional area at the levels of base of the tongue and soft palate were significantly higher in NC+ patients compared to NC- patients in all age groups.

Conclusions

This study clearly demonstrates that the application of a NC may improve retropalatal end and retroglossal airway dimensions in a pediatric population undergoing MRI examination and receiving sedation in supine position.

Radiologic Imaging in Trauma Patients with Cervical Spine Immobilization at a Pediatric Trauma Center

BACKGROUND

Pediatric trauma patients with cervical spine (CS) immobilization using a cervical collar often require procedural sedation (PS) for radiologic imaging. The limited ability to perform airway maneuvers while CS immobilized with a cervical collar is a concern for emergency department (ED) staff providing PS.

OBJECTIVE

To describe the use of PS and analgesia for radiologic imaging acquisition in pediatric trauma patients with CS immobilization.

METHODS

Retrospective medical record review of all trauma patients with CS immobilization at a high-volume pediatric trauma center was performed. Patient demographics, imaging modality, PS success, sedative and analgesia medications, and adverse events were analyzed. Patients intubated prior to arrival to the ED were excluded.

RESULTS

A total of 1417 patients with 1898 imaging encounters met our inclusion criteria. A total of 398 patients required more than one radiographic imaging procedure. The median age was 8 years (range 3.8-12.75 years). Computed tomography of the head was used in 974 of the 1898 patients (51.3%). A total of 956 of the 1898 patients (50.4%) required sedatives or analgesics for their radiographic imaging, with 875 (91.5%) requiring a single sedative or analgesic agent, and 81 (8.5%) requiring more than one medication. Airway obstruction was the most common adverse event, occurring in 5 of 956 patients (0.3%). All imaging procedures were successfully completed.

CONCLUSION

Only 50% of CS immobilized, nonintubated patients required a single sedative or analgesic medication for their radiologic imaging. Procedural success was high, with few adverse events.

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

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.

A retrospective comparison of propofol alone to propofol in combination with dexmedetomidine for pediatric 3T MRI sedation

BACKGROUND AND AIM

Both propofol and dexmedetomidine have been found to be safe and effective sedation for magnetic resonance imaging (MRI). Our program experienced an increase in patients arousing and experiencing an adverse airway event during propofol sedation for MRI in the first months of using a new 3T (Tesla) MRI scanner that was found to have a longer reverberation time compared to the previous 1.5 T MRI. In an effort to decrease patient arousal and adverse airway events during MRI, we administered a dexmedetomidine load prior to our standard propofol protocol. The objective was to compare adverse events and other outcome measures of patients sedated with propofol alone (Pro) and propofol preceded by a dexmedetomidine load (D+P).

METHODS

We reviewed a sedation database and medical records for all children undergoing 3T MRI studies while sedated with propofol alone or propofol preceded by a dexmedetomidine load in 2014.

RESULTS

Two hundred and fifty-six sedations were performed for MRI (87 Pro and 169 D+P). The two groups were comparable with regard to age, weight, gender, and American Society of Anesthesiologists status. Subjects in the D+P cohort had significantly fewer adverse events (10/169 patients (5.9%) vs 23/87 patients (26.4%) [OR 0.18, 95% CI: 0.08-0.39, P < 0.001]), particularly upper airway obstruction. Mean discharge time was longer in the D+P cohort compared to the Pro cohort (87.1, SD 26.3 min vs 69.7, SD 23.6; [mean difference 17.7 min, 95% CI: 10.6-24.8, P < 0.001]).

CONCLUSIONS

The addition of a dexmedetomidine infusion prior to our propofol MRI sedation protocol resulted in fewer sedation-related adverse events, particularly upper airway obstruction. Further studies are needed to evaluate the potential for a reduction on adverse events with this drug combination.