RESULTS: A higher sensitivity was observed in chromosomal DNA (MPRE-PCR assay), where this assay allows the detection of gelatin DNA at amounts as as low as 1 pg, whereas mitochondrial DNA (CBH-PCR assay) can only detect at levels down to 10 pg of gelatin DNA. When an analysis with commercial gelatin and gelatin capsule samples was conducted, the same result was observed, with a significantly more sensitive detection being provided by the repetitive element of chromosomal DNA.

METHODS: We conducted an observational crossover bench study to compare the cannula-to-Melker with the scalpel-bougie technique in a porcine tracheal model. Twenty-eight anesthetists participated. The primary outcome was time taken for device insertion. Secondary outcomes were first-pass success rate, incidence of tracheal trauma, and technique preference. We also compared the data on outcome measures with the data obtained in a similar workshop a year ago.

RESULTS: The scalpel-bougie technique was significantly faster than the cannula-to-Melker technique for cricothyroidotomy (median time of 45.2 s vs. 101.3 s; P = 0.001). Both techniques had 100% success rate within two attempts; there were no significant differences in the first-pass success rates and incidence of tracheal wall trauma (P > 0.999 and P = 0.727, respectively) between them. The relative risks of inflicting tracheal wall trauma after a failed cricothyroidotomy attempt were 6.9 (95% CI 1.5-31.1), 2.3 (95% CI 0.3-20.7) and 3.0 (95% CI 0.3-25.9) for the scalpel-bougie, cannula-cricothyroidotomy, and Melker-Seldinger airway, respectively. The insertion time and incidence of tracheal wall trauma were lower when the present data were compared with data from a similar workshop conducted the previous year.