We all like shortcuts. Video games have cheats to get past the boss at the end of the level. We’ve all snuck in a peak at the end of the book. Escalators are popular for a reason.
All too often when the topic of airway management comes up we take similar shortcuts. We get straight to the intubation bit. Or the equipment bling. Or the surgical airway debate.
We go straight past the first bit that seems so basic but sets up the rest of your success – the bit with the bag and the mask. This part of airway management is particularly important in kids’ anaesthesia where inhalational induction is a standard technique and there’s a good chance you’ll be managing a spontaneously ventilating patient for a bit. It is a little different to bag-mask technique for the older types and those older patients don’t tend to go through a phase of bag-mask ventilation at the time of induction in the same way.
So how good is your bag-mask technique? Paediatric anaesthetists who regularly have trainees coming through always end up spending a bit of time obsessing over this bit. Which makes it seem like a good topic for a post to share tips and tricks. Below are collated thoughts from a range of anaesthetists both old and new to the site – Dr Neil Street, Dr Donald Innes, Dr Jenny Chien, Dr Ian Miles, Dr Su May Koh and Dr Andrew Weatherall.
Rest assured we’ll get to the fancy gear and intubating bit some other time, but in the meantime here’s a few thoughts to get some chat flowing.
- Start with the Mask
“Start with the correct size mask. Unlike adult standard masks there are a lot more variations in paediatric mask sizing, shape and design. I find the cushioned clear masks the best at achieving a good seal, after ensuring that there is enough air in the actual cushion. Everything starts with the seal.” (SMK)
“The advent of clear disposable facemasks has made my practice so much easier. I routinely hold them sideways, use the edge of the mask to occlude the nose and tell the children to take large breaths in and out of their mouths. Using this technique you can rapidly go to 8% sevoflurane on most patients with little to no excitement. No more discussions about what it smells like, encourage breathing through their mouth. They won’t smell it. Rapid establishment of anaesthesia with good control is a big help.” (DI)
- Seals Should be Seals
“Beware nasogastric tubes etc. – it’s amazing how much leak around the mask they can cause and make ventilating neonates impossible. They’re better removed after suctioning but prior to induction, particularly if a difficult airway is anticipated.” (SMK)
- Open the Mouth, It’s Part of the Airway
“The tongue often ends up against the roof of the mouth which can cause obstruction. Opening the mouth, letting the tongue drop then putting your mask back on often relieves the obstruction without needing to put in an oropharyngeal airway.” (JC)
“Babies and small infants have no teeth to keep the mandible parallel to the maxilla, so you can use the bottom edge of the mask against the chin to prop the mouth open a little. This can help avoid obstruction.” (IM)
- Try Less Hard
“In smaller kids, it can be really hard to apply good bag-mask technique if you try as you would in an adult, with a digit behind the angle of the jaw and other fingers arranged along the mandible. This technique often works for me – lay your middle finger gently across the soft tissue just where the neckline starts to head up to the chin (yep, right in the midline). Gently stretch the skin up to the jaw line with that middle finger (almost like you’re pushing the little ridge of skin up to the chin). Now add the mask with your index finger and thumb holding it to the face as per normal. You should have an open airway. That’s all the effort it takes (if that’s as clear as mud, let me know and I’ll try to produce a better version).” (AW)
“A really common cause of airway obstruction is big fingers under the jaw on soft tissues. Often the best airway is maintained using the two finger technique – one under the jaw and another on top of the elbow connecting to the mask. This distributes the cushion of the mask evenly. Try too hard and you clamp down on those soft tissues.” (NS)
“Particularly in the younger ones, trying too hard can be the cause of difficulty. Keep the head in neutral position and keep your fingers away from grabbing hard on the soft tissues.” (JC)
“If you find yourself struggling harder and harder to maintain airway patency with reducing levels of success don’t be afraid to stop, remove the mask completely and start again.” (IM)
- Get Good at CPAP
“Not only will CPAP help to splint the airway open, but it will tell you instantly if you have lost the seal with the mask.” (IM)
“When people think they’re delivering CPAP, they’re often not really doing continuous airway pressure. Whichever circuit you’re using knowing how to maintain good CPAP with a seal is a real key to management of the paeds airway. This is particularly the case for episodes of laryngospasm. True CPAP, without additional efforts at ventilation, helps deal with the spasm. Use slight assistance once the respiratory effort kicks in. If you ventilate without respiratory effort, you’ll have a very well inflated stomach pretty quickly.” (NS)
“Good CPAP really helps you manage tissues that can cause obstruction at all levels of the airway. In that phase through induction where the airway can still be a bit reactive, CPAP will get you through to the bit where adding a Guedel’s can then be done safely to make things a little easier.” (AW)
- But wait, you still have to balance that pressure thing
“You do need to be wary of the pressures you are generating with your bag, T-piece or circle circuit as not all equipment is pressure limited and you have to be aware you can lose the sense of how much you’re delivering. Keep evaluating the pressure you’re using – it’s easy to create a risk of barotrauma or inflate the stomach which can cause big problems of its own.” (JC)
“Have a low threshold for inserting an oropharyngeal airway (assuming you evaluate the risk of airway reactivity at the time). Gastric distension is far more problematic in young children than adults.” (SMK)
- T-piece Specifics
I think a circle circuit is a perfectly good system for pretty much everyone but if you’re using a T-piece get a technique that gives you the full range of control. When I was shown the technique with the bag more in my palm, things got a lot easier. With this technique, you can manage your level of occlusion of the open end of the bag with digits 3, 4 and 5 while the index finger and thumb are ready to bag. You can also reduce the volume of the bag with a quick twist to reduce the volume (a 500 mL bag is very big for a little one). I like this so much more than the technique where you control the end of the bag with index finger and thumb.” (AW)
“I maintain that the T-piece is unsurpassed as the ventilating circuit in the management of any difficult airway. It is particularly good in small babies when hand ventilating where you can choke the bag off half way along. You get a better feel, smaller volumes but more effective maintenance of positive pressure.” (NS)
Who figured everyone would have that many words about a bag, a mask and an airway? Go forth, try them out, tell us what’s useful and what’s not. One of the advantages of looking after those kids who are spontaneously breathing is you can really assess if that technique is up to scratch.
Of course this is just a start and we’re not saying these are all the things that work that have ever been considered. It’s just a few words about treading lightly and keeping seals (which would also be a pretty good set-up for a nature documentary).
Got any suggestions to add? That’s what the comments are for.
That photo of a seal is an unmodified image obtained via the creative commons area of Flickr, having been posted by Airwolfhound.
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