Check the Tube. Then Check It Again.

Something a bit different this episode. We've spent this series on pumps and valves and circuits — today it's the airway, and the lung you're deliberately collapsing. Mike and Calum work through thoracic and cardiac airway management: one-lung ventilation, the difficult double-lumen tube, the shared airway, and a couple of scenarios that will catch you out badly if you haven't thought about them first. Please note: this reflects local Wythenshawe practice, and a fair amount of personal preference — flagged as such where it isn't gospel. Check your own guidelines. We start with how one-lung ventilation used to be taught — volume control, 500 mL, rate of 16, and it'll all be fine — and how completely that has changed. Bronchoscope before you turn them and again afterwards, because that tube will move. Then rather than picking numbers, find where the dependent lung actually sits on its compliance curve: start with low PEEP, hold the driving pressure constant, ramp the PEEP up a couple of centimetres at a time, and watch compliance. Most patients land around a PEEP of 6–8 with a driving pressure of 14–16 — and above 16 you're risking ventilator-associated lung injury. Driving pressure is the number to watch, not tidal volume. Then hypoxia on one lung, where the textbook answer and the real answer differ slightly. Check the tube. Then check it again — are you actually on one lung and not down one lobe, and in the correct lumen? Most of the time that's the answer. Optimise the dependent lung before you touch the other side. For the difficult double-lumen tube we cover a lubricated bougie inside the bronchial lumen with video laryngoscopy (a personal preference, and not uncontroversial), awake intubation for a truly predicted difficult airway, and exchanging a single-lumen tube over an airway exchange catheter — plus the answer that isn't a technique at all, which is asking for a second pair of hands early. Then rigid bronchoscopy and tracheal stenting: TIVA, rocuronium and sugammadex, depth of anaesthesia monitoring, and a Sanders jet ventilator on a genuinely shared airway. The centrepiece is a scenario that can trick anyone: high airway pressures coming off bypass. The answer you must hold in mind is anaphylaxis — and every classic sign works against you. It may be something the perfusionist gave, a surgical dye, a cleaning solution or a coated line. The patient is completely covered, so you won't see a rash. They're hypotensive, but hypotension coming off bypass is expected anyway. And if you then try to extubate after a lot of fluid, you may find oedematous cords. Look at the patient, look for a rash, consider anaphylaxis, and give adrenaline. We finish with anaesthetising a patient already on VV-ECMO (and why you must not do a tracheostomy on someone who isn't properly anaesthetised), restrictive pericarditis, the cardiac difficult airway, and ERAS — designing the whole anaesthetic backwards from the patient walking out. Chapters (00:00) Cold open — the lung you're deliberately collapsing (00:50) How one-lung ventilation used to be taught (02:00) Bronchoscope before and after you turn them (02:50) Titrating PEEP against compliance (04:20) When they don't tolerate one lung (05:10) Hypoxia on one-lung ventilation — check the tube first (06:30) The difficult double-lumen tube (08:00) Rigid bronchoscopy and jet ventilation (09:40) High airway pressures off bypass — think anaphylaxis (11:30) Anaesthetising a patient already on ECMO (12:40) Restrictive pericarditis and the cardiac difficult airway (13:50) ERAS: designing the anaesthetic backwards (15:00) Wrap-up Key takeaways One-lung ventilation has moved on: bronchoscope before and after turning them, because the tube moves Titrate PEEP against compliance rather than picking numbers — usually 6–8, with a driving pressure of 14–16 Driving pressure is the number to watch; above 16 you're risking lung injury If they desaturate on one lung, check the tube first — that's usually the answer Optimise the dependent lung before doing anything to the non-dependent one For a difficult double-lumen tube: bougie and video laryngoscopy, awake intubation, or exchange over a catheter — and ask for help early Rigid bronchoscopy needs neuromuscular blockade; airway trauma is reported without it High airway pressures off bypass should make you think anaphylaxis, because every classic sign is hidden or explained away A patient on ECMO having a tracheostomy needs full anaesthesia and depth of anaesthesia monitoring Turn the PEEP off in restrictive pericarditis, and have vasopressors ready at induction In the cardiac difficult airway, protect the stomach for the TOE probe and bail out to awake intubation early References / further reading Lohser J, Slinger P. Lung injury after one-lung ventilation. Anesth Analg 2015 Amato MBP et al. Driving pressure and survival in the acute respiratory distress syndrome. NEJM 2015 Campos JH. Lung isolation techniques for patients with difficult airway. Curr Opin Anaesthesiol 2010 Ahmad I et al. Difficult Airway Society 2025 guidelines for management of unanticipated difficult intubation in adults. Br J Anaesth 2025 Royal College of Anaesthetists. 6th National Audit Project (NAP6): perioperative anaphylaxis. 2018 Levy JH, Adkinson NF. Anaphylaxis during cardiac surgery. Anesth Analg 2008 Engelman DT et al. Guidelines for perioperative care in cardiac surgery: ERAS Society recommendations. JAMA Surg 2019