Front-of-neck airway rescue with impalpable anatomy during a simulated cannot intubate, cannot oxygenate scenario: scalpel-finger-cannula versus scalpel-finger-bougie in a sheep model.

BACKGROUND: Front-of-neck airway rescue in a cannot intubate, cannot oxygenate (CICO) scenario with impalpable anatomy is particularly challenging. Several techniques have been described based on a midline vertical neck incision with subsequent finger dissection, followed by either a cannula or scalpel puncture of the now palpated airway. We explored whether the speed of rescue oxygenation differs between these techniques. METHODS: In a high-fidelity simulation of a CICO scenario in anaesthetised Merino sheep with impalpable front-of-neck anatomy, 35 consecutive eligible participants undergoing airway training performed scalpel-finger-cannula and scalpel-finger-bougie in a random order. The primary outcome was time from airway palpation to first oxygen delivery. Data, were analysed with Cox proportional hazards. RESULTS: Scalpel-finger-cannula was associated with shorter time to first oxygen delivery on univariate (hazard ratio [HR]=11.37; 95% confidence interval [CI], 5.14-25.13; P<0.001) and multivariate (HR=8.87; 95% CI, 4.31-18.18; P<0.001) analyses. In the multivariable model, consultant grade was also associated with quicker first oxygen delivery compared with registrar grade (HR=3.28; 95% CI, 1.36-7.95; P=0.008). With scalpel-finger-cannula, successful oxygen delivery within 3 min of CICO declaration and ≤2 attempts was more frequent; 97% vs 63%, P<0.001. In analyses of successful cases only, scalpel-finger-cannula resulted in earlier improvement in arterial oxygen saturations (-25 s; 95% CI, -35 to -15; P<0.001), but a longer time to first capnography reading (+89 s; 95% CI, 69 to 110; P<0.001). No major complications occurred in either arm. CONCLUSIONS: The scalpel-finger-cannula technique was associated with superior oxygen delivery performance during a simulated CICO scenario in sheep with impalpable front-of-neck anatomy.

Training models for meniscal repairs and small joint arthroscopy.

BACKGROUND: The reduced availability of human cadavers and their associated high costs, coupled with an increasing requirement for meeting continuing professional development targets, has accentuated the need for alternative training models that meet current ethical standards. The aim of this study is to identify suitable substitutes that are accessible and cost effective for use as training models for meniscal repairs and small joint arthroscopy. METHOD: Ovine, bovine and porcine stifles were analysed for comparable anatomy to the human knee, arthroscopic access, arthroscopic view and ease of meniscal repair. RESULTS: The bovine stifle joint was found to be too large and offered limited access due to a large anterior fat pad and thick surrounding soft tissue. The ovine and bovine stifles were both easily available and had comparable anatomy to the human knee. Advantages of the porcine stifle include better availability and easier accessibility, comparable anatomy to the human knee and its relatively larger size that made it easier to arthroscope. CONCLUSION: Porcine stifles are cost effective, accessible, allow for meniscal repair and are suitable for arthroscopic access and view. Our view is that they are an ideal training model for arthroscopic meniscal repair, small joint arthroscopy and anterior cruciate ligament reconstruction.

Use of bovine carpal joints as a training model for cruciate ligament repair.

BACKGROUND: Currently, there is a lack of cheap and effective training models to allow orthopaedic surgery trainees to learn the basics of anterior cruciate ligament reconstruction. The aim of this paper was to investigate the viability of using various animal joints as models for the training of anterior cruciate ligament reconstruction. METHOD: Equine stifles, bovine stifles and carpal joints, sheep stifles and porcine stifles, were sourced from a local abattoir. Each joint was assessed for the following criteria: suitable tendons for harvesting, ease of arthroscopy access, adequacy of arthroscopy view and suitable joint surfaces. Tendon harvesting, preparation, joint arthroscopy and tendon tunnelling were performed on the most suitable joint. RESULTS: Equine, bovine, sheep and porcine stifles were found to be unsuitable. The bovine carpal joint was similar to a human wrist joint with two rows of carpal bones and fused metacarpal bones, but with deeper flexion - similar to a human knee joint. The distal joint space was found to provide a greater range of flexion and space than the narrower proximal joint space. The joint capsule provided sufficient integrity during saline irrigation to allow adequate visualization of joint structures. Tendons surrounding the joint were found to be of similar diameter to human hamstring tendons and easily accessible. Tendon tunnelling was successfully performed in a manner similar to human anterior cruciate ligament repair. CONCLUSION: The use of bovine carpal joints is a cost-effective, safe and easily reproducible model for education on basic anterior cruciate ligament repair skills and technique prior to patient contact.