the metablog

Opioid-free, AF anaesthesia and LMA atelectasis

Thu, 14 Nov 2024 10:37:00 +0000

Three interesting recent studies looking at specific choices around anaesthetic technique. In the Canadian Journal of Anesthesia, da Silveira reviews the benefits of opioid-free laparoscopic surgery; in the Journal of Cardiothoracic and Vascular Anesthesia, Ford goes deep on the pros and cons of different anaesthetic techniques for AF ablation procedures; and finally in the JCA, Liu reports on a single-centre RCT investigating the beneficial effects of LMAs on atelectasis.

Opioid-Free Laparoscopic Surgery: Less Nausea, Similar Pain Control

An interesting meta-analysis from da Silveira et al. explores whether we can effectively manage minimally invasive abdominal surgery without using opioids - an important question given how common opioid-related side effects are.

This was a comprehensive systematic review and meta-analysis of 26 randomised controlled trials, including 2,025 patients. The researchers specifically compared opioid-free versus opioid-containing anesthesia in minimally invasive abdominal surgeries. They were particularly interested in looking at side effects like PONV and bradycardia, as well as pain control and recovery times.

The results were quite interesting. The authors found that opioid-free anaesthesia:

Reduced PONV by 45% (from 24% to 13% / RR CI 0.40 to 0.74).
Led to slightly lower immediate postoperative pain scores (though not clinically significant).
Required less postoperative opioid use in the first 2 hours.
Showed no difference in recovery room length of stay.
Showed no increase in bradycardia, a previously noted concern when using intraoperative dexmedetomidine.

These findings are consistent with previous meta-analysis, but unique to this study, focus only on laparoscopic surgery, excluding orthopaedics and head & neck surgery included in past analyses.

"Opioid-free anesthesia showed a significant reduction in PONV and a decrease in opioid consumption during the first 2 hr postoperatively, suggesting it can be an alternative to opioid anesthesia in minimally invasive abdominal surgeries."

The (small) reduction in postop pain scores and opioid consumption is particularly notable, supporting the idea that intraoperative opioid may induce acute tolerance postoperatively. (We know this happens with remifentanil above a certain dose)

"A multimodal analgesic approach avoiding opioids with the use of lidocaine, magnesium, and ketamine suppresses impulses from injured nerve fibres and transmission of nociceptive stimuli, and may be able to promote analgesia in the first 24 hr after surgery, while reducing opioid consumption in the early postoperative period. ... Additionally, a2-agonists such as dexmedetomidine may replace opioids in terms of sympathetic stabilization, especially during major surgeries."

While the study captured a large sample size and robust statistical analysis, the authors acknowledge limitations related to study heterogeneity, "the included RCTs used different opioid-free anesthesia strategies and medication regimens".

Da Silveira and team make a strong argument for the possible superiority of opioid-free anaesthesia for laparoscopic surgery, it's worth noting that successful use of the technique requires expertise in using alternative agents like dexmedetomidine, ketamine, and regional techniques. The benefits, particularly in reducing post-operative nausea and vomiting, may be worth the learning curve.

Modern Anaesthesia and AF Ablation: What's Best?

This narrative review by Ford et al. examines the impact of anaesthetic technique on the success of catheter ablation for atrial fibrillation (AF), particularly ventilation strategies. It has relevance given that AF's is the most common arrhythmia, leading to a surge in ablation procedures.

The authors examine three key areas: general anaesthesia (GA) vs conscious sedation, high-frequency jet ventilation (HFJV), and high-frequency low tidal volume ventilation (HFLTV).

They show that GA appears superior to conscious sedation, with one study showing 88% vs 69% arrhythmia-free rates at 17 months. The GA group also experience a lower rate of pulmonary vein reconnection and shorter procedural and fluoroscopy times.

Both HFJV and HFLTV show promise in improving catheter stability and procedural outcomes. The authors note:

"GA has been shown to decrease the movement of catheter tips compared to conscious sedation, enabling better stability and lesion formation."

Though they acknowledge that HFJV faces practical challenges:

"While HFJV is known for its positive impact on catheter stability, its implementation faces challenges such as high costs, the need for additional training to use the ventilator, and the inability to measure end-tidal CO2."

HFLTV might thus offer a practical middle ground between conventional ventilation and HFJV, potentially providing similar benefits without the extra cost and training demands.

The benefits of GA, HFJV and HFLTV arise from reduced respiratory variability, leading to:

Minimising left atrial movement.
Better catheter stability, improving procedural accuracy.
More effective lesion formation.

The main weakness of the review is the lack of direct comparative data between the different ventilation strategies, which the authors acknowledge, calling out the need for randomised controlled trials comparing these strategies.

Nevertheless, the review makes a compelling argument for the use of an anaesthetic technique that avoids ventilation variability – and the less variability, the better.

Less is more: Do laryngeal masks reduce atelectasis compared to endotracheal tubes?

Liu and colleagues investigated whether laryngeal mask airway (LMA) use reduces atelectasis formation during general anaesthesia, compared to endotracheal tubes (ETT) – relevant given that ~90% of patients develop some degree of atelectasis after induction.

This was a single-centre, double-blind RCT of 180 patients undergoing non-laparoscopic surgery under 2 hours, with intention-to-treat analysis. They used lung ultrasound (LUS) scoring to assess atelectasis at various timepoints (15 min post-induction, pre-emergence and 30 min after extubation) along with oxygenation. All patients were induced with sufentanil, propofol and rocuronium, and maintained with propofol/remifentanil TIVA. Ventilation was volume controlled with TV 6-8 mL/kg and PEEP 5 cmH2O, I:E 1:1.5, RR 12-20 and FiO2 40%.

Surprisingly the LMA group showed significantly lower LUS scores at all three timepoints, along with better oxygenation and fewer postoperative pulmonary complications.

The authors propose several mechanisms to explain the superiority of LMAs:

Faster Airway Insertion

Shorter apnea time during airway placement (41 vs 95 seconds).
Less time for oxygen absorption in preoxygenated alveoli to cause absorptive atelectasis.
As they note: "Prolonged ventilation pause during this period can easily lead to excessive absorption of oxygen in the alveoli, causing absorptive atelectasis".

Reduced Airway Irritation

Less manipulation of the throat.
Reduced stimulation of airway reflexes.
Lower risk of bronchospasm and secretions.
Less risk of small airway obstruction.
Better preserved mucociliary clearance rates.

Lower Muscle Relaxant Requirements

"After anesthesia induction and administration of muscle relaxants, the weakening of inspiratory muscle tension in patients leads to a relative increase in intra-abdominal pressure. The relaxed diaphragm moves cephalad, reducing the cross-sectional area of the chest, thereby altering the geometry of the thoracic cavity and increasing chest wall pressure, subsequently compressing lung tissue and causing compressive atelectasis."

Reduced Anaesthetic Requirements

Lower doses of sufentanil and rocuronium for induction.
Lower maintenance doses of propofol and remifentanil.
Better preserved respiratory function.

Particularly relevant in this study, "the majority of surgeries in both groups being endoscopic procedures, resulting in minimal demand for anesthetic drugs. Therefore, the increase in the required dose of anesthetic drugs to attenuate cough reflex during endotracheal intubation becomes more significant." Thus the effect could be more about depth of anaesthesia and muscle relaxation than airway choice per se.

The authors note: "Compared to endotracheal intubation, laryngeal masks effectively reduce atelectasis formation and progression in gynecological, urological non-laparoscopic, and orthopedic limb surgeries."

The study is mainly limited by the lack of neuromuscular monitoring and the restriction to relatively healthy patients having shorter (mainly endoscopic!) procedures – arguably the group that atelectasis is least clinically important for!

Nonetheless, the results suggest that when appropriate, using an LMA rather than ETT may reduce atelectasis formation. The authors acknowledge this may not apply to longer procedures, laparoscopic surgery, or higher-risk patients; and naturally the risk-benefit balance of an unprotected airway versus an ETT needs to be considered.

"Rapid insertion and less airway irritation are key factors contributing to the LMA's ability to decrease the formation of absorptive atelectasis."

Mentioned studies:

CAB da Silveira, ACD Rasador, HJS Medeiros et al. Opioid-free anesthesia for minimally invasive abdominal surgery: a systematic review, meta-analysis, and trial sequential analysis. Can J Anaesth. 2024 Nov 5.
Ford P, Cheung AR, Khan MS et al. Anesthetic Techniques for Ablation in Atrial Fibrillation: A Comparative Review. J. Cardiothorac. Vasc. Anesth. 2024 Nov 1; 38 (11): 275427602754-2760.
Liu B, Wang Y, Li L et al. The effects of laryngeal mask versus endotracheal tube on atelectasis after general anesthesia induction assessed by lung ultrasound: A randomized controlled trial. J Clin Anesth. 2024 Nov 1; 98: 111564111564.

Does a GA CS increase PPD risk? Plus LMA studies & COVID vaccine optimism

Thu, 22 Jul 2021 02:04:00 +0000

GA caesarean section & post-partum depression

This large study (Guglielminotti 2020) of 428,204 New York caesarean section records (2006-2013), including 34,356 general anaesthetics (8%), investigated the association between mode of anaesthesia and post-partum depression (PPD). Other studies have shown an association between caesarean section (emergency > elective) and PPD. (Sun 2021, Xu 2017, and others), though this is the first to look specifically at general anaesthesia as a PPD risk factor.

Guglielminotti and Li found that general anaesthesia increased the odds of severe PPD by 54% (aOR 1.54, 1.21-1.95), and suicidal ideation by a massive 91% (aOR 1.91, 1.12-3.25), though not a significant increase in anxiety or PTSD.

The researchers discuss many potential causative factors, particularly known associations between GA CS & poor pain control, and subsequent pain & PPD – while also acknowledging the obvious potential for confounders. Of note patients receiving GA were older, more often non-Caucasian, had more co-morbidities, neonatal complexity, and lower socio-economic levels – also all independently associated with PPD risk.

In order to quantify the potential confounding contribution of emergency vs elective status, the researchers employed the novel E value:

To assess the impact of emergent cesarean delivery on our results, we calculated the E value associated with the aOR for the risk of PPD and suicidality. This relatively new metric takes into consideration 2 associations: (1) that between the confounder (emergent cesarean delivery) and the outcome (PPD); and (2) the association between the confounder (emergent cesarean delivery) and the exposure (general anesthesia).

An E value of 1.7 for the unmeasured confounder emergent cesarean delivery indicates that to explain away the association between general anesthesia and depression, either: (1) emergent cesarean delivery increases the risk of depression by at least 70%; or (2) emergent cesarean delivery is at least 70% more prevalent among general anesthesia than among neuraxial anesthesia. Either association is clinically plausible.

Keep it in perspective...

We already know that general anaesthesia for CS is suboptimal: it compromises both maternal experience and safety, but it should (hopefully) only ever be a chosen mode of anaesthesia when there is a true contraindication to regional anaesthesia – even at the modestly-high 8% GA rate among this New York cohort.

Looking at it from the other end, bear in mind that the modestly-faster time-to-incision for GA over regional is also of questionable neonatal benefit.

The take-home:

Just another reason to avoid GA CS when possible – but you already knew that, right?

"...general anesthesia is a potentially modifiable risk factor for PPD. This finding provides further supporting evidence favoring neuraxial over general anesthesia in cesarean delivery whenever possible."

Supraglottic airway training and manikins

Interesting prospective simulation & equipment study by way of the University of Freiburg. Schmutz et al. investigated how effective five different second generation supraglottic airway devices (SADs) performed in two common airway manikins: the TruCorp AirSim® and the crowd favourite, Laerdal's Resusci Anne® Airway Trainer™.

While ventilation was achieved in all SAD-manikin combinations, the Resusci Anne® Airway Trainer™ was associated with better and more consistent performance for SAD position, participant subjective assessment and ease of gastric tube insertion for most of the SADs. The TruCorp AirSim® did however achieve better leak pressures across most of the SADs (LMA® Supreme™, Ambu® AuraGain™, i-gel®, KOO™-SGA & LTS-D™).

But then, what are the implications for airway simulation training? The researchers correctly note that:

The most important quality of a manikin is the ability to simulate the real-world conditions and thus to give the trainee an authentic feedback.

The bottom line for SAD manikins?

While considering how manikin choice and SAD availability match with your aims for simulation training, the bigger picture is that the primary goal of any manikin-SAD coupling is real-life fidelity – and for that reason, participant subjective assessment is king. And so in this study at least, the Resusci Anne® Airway Trainer™ wins.

Head-rotation to improve LMA leak pressure?

Another interesting little airway study, this time out of Sapporo, Japan (Chaki 2021). A neat little randomised but-not-blinded study of the effect of head rotation on the oropharyngeal leak pressure of both the i-gel and LMA Supreme 2nd generation supraglottic airways.

The researchers investigated the leak pressure (OPLP) of the i-gel and LMA Supreme in paralysed patients with the head: 1. neutral, 2. rotated 30°, and 3. rotated 60°. They found that rotation of the head through 30° and 60° progressively increased OPLP by a clinically-significantly amount (0° vs 60° 5.5 cmH₂O (3.3-7.8) & 6.5 cmH₂O (5.1-8.0) respectively).

Before you get too excited...

The result however may not be reliably applicable to all populations, notably the study subjects were overwhelmingly small (x̄ ~160cm & 60kg) Japanese women (71%), receiving a TIVA muscle-relaxant anaesthetic (propofol, remifentanil, rocuronium). How well this improvement-with-rotation holds up among, for example, spontaneously ventilating large Caucasian males, is unclear.

Bottom-line

When using an i-gel or LMA Supreme 2nd generation supraglottic airway, careful head rotation to 60° may increased oropharyngeal leak pressure and so assist with ventilation troubleshooting. However head and neck rotation of anaesthetised, paralysed patients should be performed gently and cautiously – you are after all, not a chiropractor!

COVID mRNA vaccines and immune persistence

A great Good News study just published in Nature by researchers from Wash U Med investigated persisting COVID immunity following the Pfizer mRNA vaccination (BNT162b2). Turner et al. looked at the presence of not only circulating antibody-secreting B cells, but also germinal centre B cells found in the axillary lymph nodes of 14 study volunteers.

While the persistence of mRNA-vaccine induced immunity to SARS-CoV-2 has already been demonstrated to last at least 6 months, and likely 12 months, we do not yet know if or when vaccine boosters will be required beyond that.

Turner's study is particularly exciting because they found spike-protein binding B cells in the germinal centre of draining lymph nodes in all 14 post-immunisation participants for the full 15 weeks of the study. The germinal centre response was so vigorous and persistent that the researchers believe this could represent COVID-protection lasting for years.

"Ellebedy said the immune response observed in his team’s study appears so robust and persistent that he thinks that it could last for years. The researcher based his assessment on the fact that germinal centre reactions that persist for several months or longer usually indicate an extremely vigorous immune response that culminates in the production of large numbers of long-lasting immune cells, called memory B cells. Some memory B cells can survive for years or even decades..." – Dr Francis Collins, NIH Directors Blog

This study builds on the same team's earlier work (Turner 2021 May) looking at bone marrow plasma cells in those who have recovered from mild COVID infection, also showing a long-lived immune response.

COVID persistent immunity takeaway:

Although COVID-19 and developed vaccines have been circulating for only 12-18 months, these immune-response studies give some hope that the miracle of mRNA vaccines may not only be in their efficacy, but also in the longevity of protection.

Mentioned studies:

Guglielminotti J Li G. Exposure to General Anesthesia for Cesarean Delivery and Odds of Severe Postpartum Depression Requiring Hospitalization. Anesth. Analg. 2020 Nov 1; 131 (5): 1421-1429.
Schmutz A, Bohn E, Spaeth J et al. Comprehensive evaluation of manikin-based airway training with second generation supraglottic airway devices. Ther Clin Risk Manag. 2019 Jan 1; 15: 367-376.
Chaki T, Tachibana S, Kumita S et al. Head Rotation Reduces Oropharyngeal Leak Pressure of the i-gel and LMA® Supreme™ in Paralyzed, Anesthetized Patients: A Randomized Trial. Anesth. Analg. 2021 Mar 1; 132 (3): 818-826.
Turner JS, O'Halloran JA, Kalaidina E et al. SARS-CoV-2 mRNA vaccines induce persistent human germinal centre responses. Nature. 2021 Jun 28.

All Things Endotracheal

Sun, 24 May 2020 08:20:00 +0000

There have been some interesting papers recently exploring all-things endotracheal, relevant to anaesthesiologists, intensivists and emergency physicians alike.

Some challenge long-accepted dogma (ETT size), others confirm natural trends (cuffed paediatric tubes), or delve into ventilation physiology long forgotten by some of us (the ventral shift...).

Here's a brief stroll through five articles that may challenge your practice.

Choose smaller...

First, Karmali & Rose challenge the dogma surrounding endotracheal tube sizing in adult anaesthesia. They explore both the functional consequences of ETT size, good and bad, as well as the implications for airway trauma.

They describe how a modern ETT ≥ 6.0mm ID will accomodate most intraluminal devices, and in fact smaller sizes might even facilitate some airway procedures. Similarly, inspiratory and expiratory flow dynamics of smaller ETTs are inconsequential for most fit and healthy patients.

Noting that there is wide individual variation in tracheal dimensions, such that some patients are poorly served by a traditional ETT-size choice, they highlight the correlation between ETT size and airway trauma, hoarseness and sore throat, noting that for many patients a 'large' ETT offers little practical benefit.

"Instead of opting for ‘the largest tube that the larynx will comfortably accommodate’, we perhaps should consider using the smallest tube which permits the safe conduct of anaesthesia."

For routine anaesthesia of ASA 1 & 2 patients, an ETT sized 6.0-7.0 mm is probably the best balance between ventilation needs and airway trauma.

Don't cough

Yang et al.'s high quality meta-analysis explores the use of intravenous lidocaine/lignocaine to reduce a common, but potentially significant post-operative problem: coughing on extubation. Both coughing (reported incidence 15-94%) and post-operative sore throat (21-72%) are common among surgical patients.

This meta-analysis of 16 trials (though only 1,516 total subjects) showed a significant reduction in cough RR 0.64 (0.48-0.86 & NNT=5), and post-operative sore throat RR 0.46 (0.32-0.67), though no difference in laryngospasm, adverse events or time to extubation when using modern volatile agents.

However, they could make no clear recommendation of optimal timing or dose of lidocaine – although past reviews had found suggestion of a dose-effect, settling on 1.5 mg/kg as the best choice (Clivio et al. 2019).

Regardless, a simple intervention with peri-operative IV lidocaine reduces coughing on extubation and reduces post-operative sore throat, without any apparent increase in adverse events.

To cuff or not?

Shah and Carlisle address the steady shift in paediatric anaesthesia to use cuffed endotracheal tubes, beginning with the arrival of the Microcuff™ tube.

They challenge historical airway anatomy & physiology myths that once encouraged the use of uncuffed ETTs in children, and the questionable reliability of the widely-used Cole formula for tube size prediction (size = age/4 + 4; correct in only 50-75%).

More recently, Chamber's RCT compared cuffed and uncuffed ETTs in children undergoing elective general anaesthesia, and found that cuffed tubes improved ventilation and reduced short-term post-operative respiratory complications, in addition to decreasing tube changes.

Shah & Carlisle report on their updated meta-analysis, also showing that cuffed tracheal tubes in children result in fewer tube changes and less sore throat, but no difference in risk of laryngospasm.

Using a modern Microcuff™ or equivalent cuffed ETT that is 0.5 mm smaller in size than an equivalent uncuffed tube, offers functional, ventilation and safety benefits.

The ventral shift

Lumb and colleagues take us back to our physiological roots, confirming the well-known observation of a ventral ventilation shift under supine positive pressure ventilation, quantifying the contribution from the endotrachial tube itself (~16% of the change), versus from muscle relaxation and IPPV (noting some shift is also seen with an LMA under PSV).

While anaesthetists understand the detrimental effect of inadvertent endobronchial intubation, simply having the ETT tip close to the carina also worsens V/Q mismatch and is not as well appreciated. In these situations, tube withdrawal and/or 90^o rotation may improve V/Q match.

Plumbing nasal tube depths

Finally, as a bonus, Massoth et al. demonstrate that nasolaryngeal distance can be reliably predicted using their derived formula:

NLD (mm) = 1.1 × body height (cm) – 13.2

Although the accuracy of this simple formula is interesting, the authors noted the wide variability in nasal tubes from different manufacturers, particularly in length and guide markings for the same-sized tube. Thus correct ETT depth is probably better determined clinically: visually observing the cuff pass the cords, and auscultation to exclude endobronchial intubation – although this predictive-depth formula may be a useful sanity-check.

For abstracts, article summaries and full-text links:

Karmali S Rose P. Tracheal tube size in adults undergoing elective surgery - a narrative review. Anaesthesia. 2020 May 16.
Yang SS, Wang NN, Postonogova T et al. Intravenous lidocaine to prevent postoperative airway complications in adults: a systematic review and meta-analysis. Br J Anaesth. 2020 Mar 1; 124 (3): 314-323.
Shah A Carlisle JB. Cuffed tracheal tubes: guilty now proven innocent. Anaesthesia. 2019 Sep 1; 74 (9): 1186-1190.
Lumb AB, Savic L, Horsford MR et al. Effects of tracheal intubation and tracheal tube position on regional lung ventilation: an observational study. Anaesthesia. 2020 Mar 1; 75 (3): 359-365.
Massoth C, Schülke C, Köppe J et al. Nasolaryngeal Distances in the Adult Population and an Evaluation of Commercially Available Nasotracheal Tubes. Anesth. Analg. 2020 Apr 1; 130 (4): 1018-1025.

More related articles can also be found on metajournal's intubation, tracheal tube, and mechanical ventilation topic pages.

Five things I love about the C-MAC

Sat, 06 Aug 2016 22:53:00 +0000

Ah, videolaryngoscopes – wonderful toys increasingly common in operating rooms, intensive care units and emergency departments throughout the world.

After the first video laryngoscope was conceived by New York emergency physician Jon Berall in 1998, commercial success quickly followed with the 2001 Glidescope (designed by a vascular surgeon nonetheless!). Our love of the videolaryngoscope has grown ever since.

Like many anaesthetists and anesthesiologists I've used several different videolaryngoscopes over the past few years. The character that sets apart the videoscopes I like to use from those I do not is how well they enhance airway techniques I use every day rather than requiring a new technique specific to their device.

Overwhelmingly this comes down to how similar the laryngoscope is to a standard Macintosh blade rather than inventing a whole new shape. While there may be theoretical (or even real!) benefits to increasing the angle of the blade or adding extra conduits, when I have a difficult airway I want to augment the tools and techniques I use every day rather than change to something completely different. (When I want to change to something completely different I'll pick up a fibreoptic bronchoscope or something sharp!)

And this the first reason why I love the Storz C-MAC...

1. It uses standard Macintosh size 3 and 4 blades

(and a 'D' blade, if that floats your boat), enhanced by video which typically improves the Cormack-Lehane view by at least one.

In an unexpected difficult intubation my first go-to choice is the C-MAC and a bougie – and it has only let me down once.

This is a key point: the Macintosh-based videoscopes extend existing airway techniques, like tube-over-bougie, rather than inventing something new. A new technique is not necessarily a bad thing, but I'd rather stick with what I know when I'm in the airway vortex.

2. The C-MAC is quick to setup but difficult to loose.

Compared to the theatrical production of setting up a traditional FOB, lightsource and tower, calling for the C-MAC requires it only to be wheeled in and turned on.

Although the separate monitor and stand make it less portable than an all-in-one unit (though still a C-MAC option), the standalone monitor makes the C-MAC harder to loose if forgotten in a distant operating room, radiology or elsewhere.

The monitor can also be used with the Storz video endoscope – very useful in the heat of the moment to quickly swap out one airway weapon for another. It's also much faster to use the CMAC-endoscope de novo compared with a traditional FOB and tower.

3. The C-MAC is great for teaching junior doctors laryngoscopy technique.

"What do you see?" [silence] "What do you see?" [crickets]

Because it is a standard Macintosh blade, junior staff can use it like a normal laryngoscope under direct vision and I can watch on the C-MAC monitor, offering meaningful suggestions and understanding a little better where they might be going wrong.

For junior staff this is a great way to identify laryngoscopy 'threshold concepts' that they might struggle with (blade tip perfectly in the vallecula; vectors of force) – and for senior trainees the perfect way to support their management of a difficult airway without taking over.

While technical skill is a foundational part of difficult airway management, it's the decision making that determines a good or bad outcome. A senior trainee driving a videolaryngoscope allows the supervising clinician to support the decision making process.

The external monitor also allows others to see the airway view: an anesthesia assistant can see the screen and alter BURP as needed, and my surgeons can understand a little better the degree of airway challenge.

4. The C-MAC can be used for awake laryngoscopy.

With careful topicalisation and a co-operative patient, gentle awake laryngoscopy can quickly validate (or not!) the plan in suspicious airways – particularly when an awake FOB intubation is not an option.

5. The C-MAC can be cleaned quickly

Making it ready for use by the next patient, without need for disposables or consumables.

Processing a fibreoptic bronchoscope can easily take 45 minutes – an eternity when you. need. it. now!

The C-MAC is not the only game in town when it comes to Macintosh-videolaryngoscopes, though it has the greatest mindshare in the departments that I have worked in. From the range of videoscopes I have tried, the C-MAC is the one I am happiest with.

The challenge with airway toys is that because there are so many options it's easy to have superficial exposure to many but limited depth in any – and this is what I like about the C-MAC and other Macintosh-based videolaryngoscopes: they leverage the skills I've already earned in wielding Sir Robert's blade.

Want to read more on videolaryngoscopes like the C-MAC?
Click to browse metajournal.com’s indexed papers on videolaryngoscopy. Enjoy!