Author: Tucker Matthews, MD
It’s time for edition 2! I never really gave much of a background for this, but my goal is stay up to date on the airway literature coming out, and to maybe help others do the same in the process. So these are all going to be papers hot off the press that I read through and write a little summary about with my thoughts. Here are four more!
Paper 1: Carter A, Jensen J L, Walker M, et al. (August 08, 2022) Paramedic Endotracheal Intubation Success Rates Before and After an Intensive Airway Management Education Session. Cureus 14(8): e27781. doi:10.7759/cureus.27781
Methods: These authors conducted an intensive 10 hour airway management course for paramedics and compared intubation success the year before and the year after.
-674 attempts before, 143 during, and 604 after
-First pass success rates improved from 68% to 75%
-Success rates were maintained for the entire 12 months after the course (sort of…)
-Number of attempts for successful ETT placement decreased as well
There are some definite limitations here. First, it’s self-reported, and nobody wants to admit they sucked. Especially after taking a course to make you better. They also weren’t able to collect outcomes on the patients once they hit the hospital. So maybe the 7% of patients that they’re now able to get tubes into, did just as bad, or even worse, in regards to clinical outcomes.
It was also a really oddly written paper, that didn’t actually include much of the data in the actual text. There’s still some pretty interesting stuff here though. I think my main takeaway, which the authors didn’t really touch on, is that these rates just didn’t really increase all that much. For a course that is pretty time-intensive (you have to have trainers, resources, and then get every single paramedic to do this), the benefit was only 7% over the first year. And there seemed to be a possible regression in success rates over the final six months, maybe indicating loss of knowledge. So they really need further tracking past the one year mark.
Overall I just still feel like LMAs are the way to go. Even after the course, there are still ¼ of patients here who they couldn’t get a tube in, so why not just save time and slide in an LMA.
Summary: An intensive airway intervention course was able to increase first pass success rates and decrease number of intubation attempts for paramedics in the year following the intervention. Nonetheless, the improvement was small, and it is unclear whether there would be any improvements to further patient outcomes.
Kanaris C, Murphy PC. Fifteen-minute consultation: Intubation of the critically ill child presenting to the emergency department. Archives of Disease in Childhood – Education and Practice 2022;107:330-337.
Methods: This is an expert opinion from a PICU doc and a pediatric anesthesiologist, on intubating pediatric patients in the Emergency Department setting.
What they say: Any sign of poor perfusion should lead to 10cc/kg IV fluid boluses (aliquots) in addition to peripheral inotropic support, for which they suggest epinephrine.
Don’t hesitate to get an IO, as peripheral lines are harder in kids, and central and arterial lines often come with the problem that the provider has not performed many in pediatric patients, and so it will likely take longer and have greater risk of complications.
We don’t retain information well during times of stress, and so checklists are important. They provide theirs and it looks pretty good.
The younger the patient, the faster the onset of apneic desaturations, and so we really need to do good pre-oxygenation, ideally with HFNC, so that apneic oxygenation can also take place.
We should really only use cuffed tubes, sized via our classic conversion (age/4 + 3.5).
Use a smaller tube if the patient has croup.
They argue for ketamine and rocuronium, both at 1mg/kg; with 1microgram/kg of fentanyl as a plus/minus.
If patient is predicted to have a difficult airway, don’t mess around; call for anesthesia and/or ENT, along with a PICU specialist ASAP. These should ideally be done by the most experienced operator in the room, and so, this really isn’t a time for a trainee.
The job obviously doesn’t end with successful ETT placement. It’s critical to immediately focus on proper sedation, along with ensuring haemodynamic stability. It’s also a good idea to have a team debrief, and then to make sure to update the family.
Thoughts: There’s not a lot here that’s overly different from intubating an adult patient, but there are still some really good tips/reminders for proper intubation skills and setup.
Summary: Pediatric intubations are relatively infrequent, and so we should be fully prepared beforehand for whatever might happen. Make sure to expect the worst, and to call for help if there’s any indication that it might be difficult.
Paper 3: Foorman B, Utarnachitt RB, Danielson K, Brookie T, Henry L, Latimer A. Prolonged Use of an Extraglottic Airway During Air Medical Transport From a Remote Alaskan Island. Air Med J. 2022 Sep-Oct;41(5):491-493. doi: 10.1016/j.amj.2022.06.004. Epub 2022 Jul 15. PMID: 36153148.
Methods: A case report detailing a 9 hour prehospital course from a medical clinic to a tertiary hospital, utilizing an extraglottic device (EGD) as means of airway management.
The case: The patient was a 25 year old woman who was hit in the head by a metal object, and then covered in gasoline and lit on fire. She initially had intact ABCs, and a GCS of 15, and was brought by EMS from her home to a rural medical clinic. She had a right frontal scalp laceration, and burns to her face, anterior neck, and bilateral upper and lower extremities (not stated the extent or burn depth). She developed respiratory distress, and unfortunately, the providers gave 3 unsuccessful attempts at intubation with RSI, after which they placed a King airway.
The patient began to develop significant lip, tongue, and airway edema, and so the providers and transport personnel were concerned that removing the EGD to reattempt intubation would potentially make it so that they were unable to replace the EGD if they again failed at intubation. So they initiated transport to the tertiary care center, with plans to do a surgical airway if the EGD failed. For transport, they hooked her up to the vent, paralyzed her with vecuronium, and ran morphine and midazolam for sedation. Transport went swimmingly, and on arrival she was taken to the OR for a tracheostomy. She was eventually discharged home in stable condition after a 5 week hospitalization.
Thoughts: This is just too cool. I love rural medicine, so I had to pick this. It’s really just a fascinating story, but I also think it’s a good reminder that EGDs are still really good airways. I haven’t personally really interacted with King airways or combi-tubes in my experience, but it still holds true for LMAs and i-gels (both considered supraglottic devices). One thing I wonder though is how this case would have gone with a supraglottic airway, given the extent of her edema.
Summary: Extraglottic devices are great airways, and if we can’t intubate, it’s definitely worth considering them instead of just jumping towards a surgical airway (or a prolonged time with a BVM).
Paper 4: Hansel J, Rogers AM, Lewis SR, Cook TM, Smith AF. Videolaryngoscopy versus direct laryngoscopy for adults undergoing tracheal intubation: a Cochrane systematic review and meta-analysis update. Br J Anaesth. 2022 Oct;129(4):612-623. doi: 10.1016/j.bja.2022.05.027. Epub 2022 Jul 9. PMID: 35820934.
Methods: This is an abridged version of the updated Cochrane systematic review and meta-analysis comparing VL and DL. They were able to add an additional 158 new studies to the original 64, for a total of 222 RCTs with 26,149 patients.
Notable results: They specifically wanted to analyze the safety profiles of VL devices, and to separate the VL devices into Mac-style, hyperangulated, and channeled (the tube slides through the blade). The original Cochrane used 64 studies of 7044 patients, and demonstrated evidence that VLs may improve glottic visualization while also reducing incidences of failure. They had not, however, split up the blade types. The critical outcomes measured were failed intubation, hypoxaemia, successful first attempt, and oesophageal intubation. Failed intubation was defined as >3 attempts, or a change of device or intubator. Hypoxaemia was defined as oxygen saturations <94%.
Mac-style VL was favorable over DL for minimizing intubation failure, hypoxaemia, and for increasing rates of first pass success (RR of 0.41, 0.72, and 1.05, respectively). There was no difference in rates of oesophageal intubation.
For hyperangulated VL versus DL, there was again a decreased risk of intubation failure (RR 0.51), though no decreased risk of hypoxaemia (large confidence interval that crossed 1). There was just barely an increased likelihood of first attempt success, with a RR of 1.03 and a CI from 1.00 – 1.05. There was a RR of 0.39 for oesophageal intubation.
Finally, when comparing the channeled videolaryngoscopy against DL, there was a decrease in intubation failure (RR 0.43) and hypoxaemia (RR 0.25), with an increased likelihood of first attempt success (RR 1.10). There was no difference in rates of oesophageal intubation.
They also attempted to perform subgroup analyses to find factors that would predict increased likelihood of failure, however, there generally weren’t enough studies to do this. They did note though, that during situations of anticipated difficult airways, the hyperangulated VL performed significantly better than DL setups.
Thoughts: It would be interesting to compare between the different VL mechanisms, but obviously that isn’t possible here given the original RCTs. There’s also the difficulty of interpreting data from a combination of prehospital, ED, OR, and ICU settings. Overall, it’s really an awesome compilation of these data though, and it certainly seems to indicate that VL is probably the way to go. Obviously, it’s unclear if any of these documented outcomes lead to changes to important patient-centered downstream outcomes, as these were rarely reported.
Summary: The current evidence seems to suggest that videolaryngoscopy outperforms direct laryngoscopy on a number of crucial outcomes, regardless of the specific blade design used.