The effect of anti-spasmodic administration on the accuracy of magnetic resonance imaging staging of rectal cancer.

BACKGROUNDS: Magnetic resonance imaging is the primary method for local staging in rectal cancer patients. Administration of intravenous (IV) hyoscine butylbromide is thought to improve accuracy, but there are contraindications and potential adverse effects. The aim was to assess the efficacy of IV hyoscine butylbromide on the accuracy of MRI rectal cancer staging of T2 and T3 rectal cancers. METHODS: A retrospective cohort study was carried out on patients prospectively recorded on the Cabrini Monash colorectal neoplasia database. A total of 74 patients (53 males, 21 females) MRI pelvis and rectums with antispasmodics were performed at multiple centres in the pre-operative setting between 2010 and 2016. Each patient underwent total mesorectal excision of rectal cancer. The excision specimens were assessed and given a pathological TNM stage, which was considered the reference standard. RESULTS: There was no statistically significant impact on the overall accuracy of MRI rectal cancer staging between patient groups who received IV hyoscine butylbromide and groups who did not receive IV hyoscine butylbromide. The accuracy of T2 and T3 staged rectal cancers was more likely to be correct (compared with T1 cancers) with the administration of IV hyoscine butylbromide. Still, there was no improvement in the accuracy of N-staging. CONCLUSION: Given the potential side effects and adverse outcomes of IV anti-spasmodic agents, department protocols may need to be re-assessed regarding the prescription of these medications for MRI rectal cancer staging.

Emergency Front-of-Neck Airway Rescue Via the Cricothyroid Membrane: A High-Resolution Computed Tomography Study of Airway Anatomy in Adults.

BACKGROUND: Emergency front-of-neck airway rescue is recommended in a can't intubate, can't oxygenate clinical scenario. Cannula cricothyroidotomy has been reported as having a high failure rate. Our primary aim was to estimate the angle of the trachea in relation to the horizontal axis in a simulated emergency front-of-neck airway rescue position. Our secondary aims were to estimate the optimal cannula angle of approach and evaluate the anatomical relationship of the cricothyroid membrane (CTM) to adjacent structures. We also assessed whether the CTM lies above or below the neck midpoint, a point equidistant from the suprasternal notch (SSN), and the chin surface landmarks. All measurements were compared between the male and female subjects. METHODS: Subjects having elective computed tomography of their thorax were consented to have extension of the computed tomography to include their neck. A preliminary radiation dose and risk assessment deemed the additional radiation to be of very low risk (level IIa). Subjects were positioned supinely on the computed tomography table. Standard neck extension was achieved by placing a pillow under the scapulae and a rolled towel under the neck to simulate emergency front-of-neck airway rescue positioning. RESULTS: Fifty-two subjects were included in this study: 31 men and 21 women. The mean angle of the trachea in relation to the horizontal axis was 25.5° (95% confidence interval [CI], 21.8-29.1) in men and 14.0° (95% CI, 11.5-16.5) in women. The mean minimum angles required for hypothetical cannula cricothyroidotomy for men and women were 55.2° (95% CI, 51.8-58.7) and 50.5° (95% CI, 45.4-55.6), respectively. The CTM was located lower in the neck in men compared to women. The CTM was located below the neck midpoint in 30 of 30 (100%) male subjects and 11 of 20 (55%) female subjects (P < .001). CONCLUSIONS: The trachea angulates posteriorly in a simulated emergency front-of-neck airway rescue position in supine subjects and to a greater degree in men compared to women (P < .001). The minimum angle required for hypothetical cannula cricothyroidotomy was >45° in the majority (75%) of subjects studied. A steeper cannula angle of approach may be more reliable and warrants further clinical study. If airway anatomy is indistinct and performing a vertical scalpel cricothyroidotomy, consideration should be given to performing this incision lower in the neck in men compared to women.