Airway

LETTER TO EDITOR
Year
: 2020  |  Volume : 3  |  Issue : 3  |  Page : 159--160

A variation in the Macintosh laryngoscope design: Is it really helpful?


Priya Rudingwa, Meenupriya Arasu, Balaji Kannamani, Sakthirajan Panneerselvam 
 Department of Anaesthesia and Critical Care, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India

Correspondence Address:
Dr. Meenupriya Arasu
Department of Anaesthesia and Critical Care, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry - 605 006
India




How to cite this article:
Rudingwa P, Arasu M, Kannamani B, Panneerselvam S. A variation in the Macintosh laryngoscope design: Is it really helpful?.Airway 2020;3:159-160


How to cite this URL:
Rudingwa P, Arasu M, Kannamani B, Panneerselvam S. A variation in the Macintosh laryngoscope design: Is it really helpful?. Airway [serial online] 2020 [cited 2021 May 11 ];3:159-160
Available from: https://www.arwy.org/text.asp?2020/3/3/159/304849


Full Text



Airway management in infants is challenging and unique taking into consideration the anatomical and physiological differences from that of adults. The high oxygen requirement and the unfavourable ratio of alveolar ventilation to functional residual capacity provide limited safe apnoea time during laryngoscopy. The choice of laryngoscope blade depends on the preference and experience of the anaesthesiologist. Although the Miller blade is recommended for children below 2 years,[1] it has not been found to provide better intubating conditions as compared to that of the Macintosh blade.[2] The availability of a zero size and the acquaintance with Macintosh blade could be a reason for its preference in infants.

We would like to share our experience while using a modified Macintosh blade (size 0) with an altered design which led to an unfavourable view during laryngoscopy. The original Macintosh laryngoscope (available as the English profile) [Figure 1] has a smooth, gentle curve and a flange that starts at the base and continues to the tip in a gradually narrowing manner. The modified Macintosh blade (available as the American profile)[3] has an abrupt curvature, the flange and the web end midway proximal to the tip [Figure 1]. The absence of the web in the distal part of the modified Macintosh blade (American profile) causes the relatively large tongue in infants to hang over the blade and bulb, obscuring the view of the glottis and leading to suboptimal lighting. This further results in a reduction of the space available for the advancement of the endotracheal tube.{Figure 1}

This alteration in design has probably been made with an intention to make the blade less bulky and the tip smaller, which would allow more space for negotiation of the endotracheal tube.[3] On the contrary, we found that by compromising the view and illumination, this modification makes laryngoscopy difficult even for experienced anaesthesiologists while intubating eight infants with normal airways. However, under the same intubating conditions, transition to the Macintosh blade (English profile) obviated the difficulty, resulting in successful intubation. Considering these issues, we would like to suggest that caution has to be exercised while using the Macintosh blade (American profile) in infants. Although with experience one may gain expertise in its use, novices may encounter this difficulty which could potentially increase the number of laryngoscopy attempts and lead to airway injury in infants. Hence, it would be pragmatic to keep a standard Macintosh blade or Miller blade as a standby should this problem be encountered.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Fiadjoe JE, Litman RS, Serber JF, Stricker PA, Cote CJ. The pediatric airway. In Cote C, Lerman J, Anderson BJ, editors. A Practice of Anesthesia for Infants and Children. Philadelphia:Elsevier;2019. p. 1437-40.
2Passi M, Sathyamoorthy M, Lerman J, Heard C, Marino M, Thompson JP. Comparison of the laryngoscopy views with the size 1 Miller and Macintosh laryngoscope blades lifting the epiglottis or the base of the tongue in infants and children <2 yr of age. Br J Anaesth 2014;113:869-74.
3Dalvi NP, Sayed NI. Laryngoscopes. In Baheti DK, Laheri VV, editors. Understanding Anesthetic Equipment & Procedures: A Practical Approach. India:Jaypee Brothers Medical Publishers;2015. p. 150-1.