Several indications for OLV, commonest are thoracic surgery & some oesophagectomies. Essentially three ways to achieve OLV - use of:
- Double lumen tube
- Bronchial Blocker
- Elective endobronchial intubation
Here are some #OnePagers covering the basics #JanuAIRWAY 2/9
The key physiological change is the creation of a large shunt – deoxygenated blood (which would normally be oxygenated), returns to the left heart resulting in hypoxaemia. #JanuAIRWAY 3/9
Often OLV is done in the lateral decubitus position. This has several effects on V/Q relations. As we can see in these diagrams. #JanuAIRWAY 4/9
Evolution is amazing, because we have a friend to help us deal with shunt – hypoxic pulmonary vasoconstriction. Bottom line – mechanism is complicated, it’s biphasic, aims to decrease shunt to non-ventilated lung – can be influenced by several factors. #JanuAIRWAY 5/9
Our tips for OLV:
- Choose your airway wisely – get it right first time – use a fiberoptic scope
- If using bronchial blocker – consider going outside ETT.
- Be aware of physiological interplay
- Plan to deal with hypoxaemia
A knowledge of bronchoscopic anatomy is incredibly useful in anaesthesia / critical care – especially when performing OLV. Here’s a pair of #OnePagers covering the basics #JanuAIRWAY 7/9
#JanuAIRWAY Day 16 (we’re over ½ way!) Cannot Intubate Cannot Oxygenate (CICO) Scenario - Needle Techniques. Potentially controversial (DAS primarily advocates scalpel techniques), but worth knowing about - particularly for paeds! Here’s some #OnePagers to start.. #JanuAIRWAY 1/7
CICO Key = decide on your plan before you're in the situation. @dasairway promotes scalpel techniques (final common pathway of CICO) MUST be taught. For more on the Needle technique check of Dr Andy Heard’s work at the Perth ‘wet’ lab. 🔗bjanaesthesia.org.uk/article/S0007-… #JanuAIRWAY 2/7
Integrating the needle technique into CICO algorithms could look something like this #OnePager. There are 2 scenarios for each technique (needle & scalpel):
-palpable and
-impalpable anatomy
another reason to decide early –> lower cognitive load. #FOAMed #JanuAIRWAY 3/7
#JanuAIRWAY Day 15. Tracheostomies – more than just an ETT through the neck. Here’s a #OnePager covering some of the different tube types. Let’s dive in… #JanuAIRWAY 1/9
Tracheostomies have potentially been performed since ancient Egypt. The first non-emergency trache was thought to be performed by Asclepiades. He was also a proponent of music therapy (might be of interest to Veena). #JanuAIRWAY 2/9
There are 4 basic indications for tracheostomy: 1. Provide patent airway 2. Protect the airway 3. Clear secretions 4. Aid weaning from ventilator – the timing of which was investigated in the Tracman study in 2013 (jama.jamanetwork.com/article.aspx?a…) #JanuAIRWAY 3/9
#JanuAIRWAY Day 13. Jet Ventilation – this is a bit more niche in anaesthesia / airway management, but fascinating. Here’s a #OnePager covering the basics. Let’s dive in… #JanuAIRWAY 1/8
2 modes of jet ventilation – low frequency (<60 jets/min) & high frequency (>60). Frequency determines device. 2 commonly used devices – Manujet (modified hand operated Sanders injector) or Monsoon (specialised jet ventilator). Here’s a some #OnePagers #JanuAIRWAY 2/8
Several different potential mechanisms to apnoic oxygenation during HFJV, including:
-Bulk flow
-Laminar flow
-Taylor dispersion
-Pendelluft
-Molecular diffusion
-Cardiogenic mixing derangedphysiology.com has a great article & this diagram #FOAMed #JanuAIRWAY 3/8
#JanuAIRWAY Day 12. Awake Techniques (ft. expert contributions from @dr_imranahmad). This is a key skill for an airway manager. Here’s a #OnePager covering the basics of Awake Tracheal Intubation (ATI) and nasendoscopy. Let’s dive in… #JanuAIRWAY 1/11
Key = topicalization (if right, may not need sedation). Top tips:
- Know nerve supply CN V, IX & X.
- Block Ant.ethmoidal AND Sphenopalatine ganglion supply to the nasal septum #JanuAIRWAY 2/11
Often you don’t need high dose LA if in right spot – this video is @Vapourologist after only gargling instilagel. #JanuAIRWAY 3/11
#JanuAIRWAY Day 11. The Aintree Intubation Catheter – an amazingly useful piece of equipment – every airway practitioner should be familiar with. Here’s a #OnePager. Let’s dive in… #JanuAIRWAY 1/5
Main function is as a stop-gap to maintain tracheal access & facilitate tracheal intubation through a supraglottic airway device (SAD) using a fibreoptic scope. They are Long, hollow, semi-rigid, powder blue, polyurethane catheters #JanuAIRWAY 2/5
To highlight: NEVER insert beyond 26cm. NEVER insufflate with an oxygen flow >2l/min … or just NEVER use for insufflation! #JanuAIRWAY 3/5
#JanuAIRWAY Day 10. The Cook Airway Exchange Catheter – it’s a useful piece of equipment, but one not everyone will be familiar with. Here’s a #OnePager. Let’s dive in… #JanuAIRWAY 1/6
Main function is as a stop-gap to maintain tracheal access & facilitate ETT exchange. They are long, hollow, radiopaque, soft-tipped tubes – types for use with single / double lumen tubes. #JanuAIRWAY 2/6
All users MUST be trained & knowledgeable of how to use such devices together with their limitations and dangers. The Gordon Ewing case makes for tragic reading – but highlights this point. Essential reading for airway practitioners.
🔗scotcourts.gov.uk/search-judgmen… #JanuAIRWAY 3/6