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The frst or tracheal intubation was reported by Sir William
Macewen
1
as a measure for providing ventilation in a patient of glottis
oedema and for administering Chloroform anaesthesia. But during
that time, visualisation of the glottis for inserting the tube into the
trachea was done indirectly, by using a combination of mirrors. In
1913 Chevalier Jackson
2
used direct laryngoscopy with the help of a
blade that had a light source at the distal tip. This made intubation a lot
easier than what was done earlier. Further modifcation in the design
of the laryngoscope blade and the laryngoscope were done by Sir
Ivan Magill
3
who also designed the Magill Forceps. The laryngoscope
which is used now a day was introduced by Sir Robert Macintosh
4
. It
was a curved blade, with a distal light source and phalange to create
space in the mouth. For more than half a century now, his design
has remained unchallenged and his instrument has remained as the
handiest and widely used device for intubation in all areas of the
Operation Theatre, ICUs and emergency rooms worldwide.
But despite of the universal design, the laryngoscope failed
to intubate in some patients, as the vocal cord visualisation was
insuffcient or sometimes even impossible. Many unexpected deaths
occurred in the Operation Theatres and emergency rooms, just because
the anaesthesiologists were unable to visualise the vocal cords and
intubate the patients. The patients were not timely ventilated and died
on the OT table itself, even before the beginning of the surgery. So,
there was a search for an ‘aid’ which could facilitate the process of
intubation. In 1949, Sir Macintosh
5
published a case report describing
the use of a gum elastic urinary catheter as an endotracheal tube
introducer. Inspired by his report, in 1973, P Hex Venn
6
developed
Eschmann endotracheal tube introducer
.
Later on, the concept of
intubation stylet was introduced in 1978, by Finucane & Kupshik
7
who used Central Venous Catheter for the purpose. Now a day we
have many types of intubation aids like Gum elastic Bougie, Frova
Intubation Catheter, Flexitip stylets, Light wands etc, which have
increased the manuverbility of the tube inside the oral cavity and have
made diffcult intubations quite possible to negotiate.
Another breakthrough in the history of intubation was the
invention of Fibreoptic bronchoscope by Shigeto Ikeda
8
. Though it
was invented, to visualise the pathologies of tracheobronchial tree,
but because its manuveribility and due to its thin size of 5-6 mm, it
became an essential component of every Anaesthesia Department’s
‘Diffcult Airway Cart’. With the help of fber optic bronchoscope,
virtually every case of diffcult intubation, like patients of facial
burns, syndromic babies who had their airway anatomy distorted,
was now possible and within Anaesthetist reach. But despite of these
advantages in intubation, the bronchoscope had the drawback of
high cost and requirement of more time for assembly and cleaning,
which made it diffcult to use in Emergencies and unexpected diffcult
intubations. Its camera if it was soiled with blood, made it very diffcult
to visualise the vocal cords and intubate the patients. The patient
had to be awake and cooperative for the procedure to which caused
discomfort. Nevertheless, Fiberoptic bronchoscope has been a very
useful device for all cases of planned diffcult airway management
cases in the Operation Theatre and ICU.
Another new development in the history of intubation was the
incorporation of cameras, LCD screens and digital technology in the
laryngoscopes. These new devices are based on indirect laryngoscopy
instead of Direct Laryngoscopy of the Macintosh Blade. A live video
of the glottisis available on the screen, which can be seen not only by
the anaesthetist who is performing the procedure but other persons
in the OT also. These videos can be recorded and snapshots can be
taken for teaching purposes. Many of these Video laryngoscopes have
channels to carry the tube to the glottic opening and special shapes
which have reduced the diffculty in diffcult intubation cases. King
Vision Videolaryngoscope
9
which is marketed by Ambu has a channel
to carry the tube and is useful, where larynx is anteriorly placed and
neck movement is restricted. Its blades are disposable providing better
hygiene in infected patients. It has an added advantage of being low
cost and handy. C-Mac D blade laryngoscope (by Storc)
9
requires
less mouth opening for insertion of the blade and has better success
rate in anterior larynx. It has internal rechargeable battery and has
buttons for taking screenshots. In Vividtrach,
9
images are displayed
on a connected laptop, which can be seen by other people also. And
according to manufacturer there is no need to tilt the head during
intubation. But despite these advantages, these video laryngoscopes
have a certain learning curve and require some amount of practice
before one achieves 100% success with them. They also have issues
in cases where there is blood or too many secretions in the oral cavity
because these soils the camera lens and obscure the vision, making
intubation diffcult. The cost of these newer devices is in between 1 to
5lacs. King Vision is a low-cost alternative and is available at a price
below 1lac. But its blades are disposable which increase the usage
prices. Nevertheless, Video laryngoscopes have proved to be very
handy and useful devices. They can be assembled within seconds and
intubation can be achieved within 15 to 30 seconds similar to that
of Macintosh Laryngoscope. In cases where patient’s oral anatomy
is normal, these devices are now proving to be even superior to the
Fiberoptic bronchoscope.
MOJ Surg. 2018;6(3):84‒85. 84
© 2018 Gupta et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which
permits unrestricted use, distribution, and build upon your work non-commercially.
Newer intubation techniques: a journey
Volume 6 Issue 3 - 2018
Abhinav Gupta, Shalu Singh, Harikishan
Mahajan
Machine Learning Department, Carnegie Mellon University, USA
Correspondence: Abhinav Gupta, Machine Learning
Department, Carnegie Mellon University, USA,
Email drabhinav.isic@gmail.com
Received: March 26, 2018 | Published: May 08, 2018
MOJ Surgery
Opinion
Open Access
Opinion
Tracheal intubation is the placement of a fexible plastic tube
into the trachea through mouth or nose. This tube acts as a conduit
to deliver oxygen and other gases from an external source like a gas
cylinder, Ventilator or an Anaesthesia machine into the lungs. It is a
widely used practice for providing mechanical ventilation to critically
ill patients in ICU and Emergency Rooms. Intubation is also used to
deliver Anaesthetic gases to unconscious patients in operation theatres
and to prevent soiling of lungs by gastric secretions in comatose
patients. It is also the primary step in all types of resuscitation
treatments in trauma and cardiac arrest situations.