I read with interest the article by Park et al [1], comparing tracheal intubation using the Airtraq with the lightwand during routine airway management. The authors report no difference in heart rate or mean arterial pressure (secondary outcomes) between the two groups, and it is on this point that I would like to comment.

The main focus of their study was to compare the intubation time, success rate and ease of use of each device, which is reflected in the design and methodology of their study. However, the authors also recorded mean arterial pressure and heart rate at various points pre- and post- intubation. However, their exclusion criteria during patient recruitment does not include patients with cardiovascular disease, or those taking antihypertensive or vasoactive drugs. The authors also fail to report the model and manufacturer of their non-invasive arterial blood pressure monitor, whether it had been recently calibrated, and if the selection of blood pressure cuff was correctly sized [2-3]. All of these points would have been appropriate to report in a study where cardiovascular responses are being compared. Furthermore, in the results section, the cardiovascular data recorded is not provided in either tabular or graphical format. This omission is unfortunate, as it may have helped to support their observations. 

The authors conclude that the reason that their investigation found no haemodynamic difference between the groups was that neither the Airtraq nor the lightwand lift the mandible. An alternative explanation for this could be in their choice of opioid. In previous studies comparing pressor responses, a bolus of fentanyl was invariably administered at induction [3-5], but the authors chose to use remifentanil by bolus and then an infusion. It is therefore possible that their choice of opioid and anaesthetic technique may have suppressed the cardiovascular response following tracheal intubation. Until the results from further studies are available, the haemodynamic responses in this study and their subsequent conclusions should be interpreted with caution.

JL Tong

The Royal Centre forDefence Medicine, Birmingham.

References

1.     Park EY, Kim JY, Lee JS. Tracheal intubation using the Airtraq: a comparison with

         the lightwand. Anaesthesia 2010; 65:729-32.

2.     Tong JL, Smith JE. Cardiovascular changes following insertion of oropharyngeal

         and nasopharyngeal airways. British Journal of Anaesthesia 2004; 93: 339-42.

3.     Tong JL, Ashworth DR, Smith JE. Cardiovascular responses following

         laryngoscope assisted fibreoptic orotracheal intubation. Anaesthesia 2005; 60: 754

        -758.

4.     Maharaj CH, O'Croinin D, Curley G, et al. A comparison of tracheal intubation

       using the Airtraq or the Macintosh laryngoscope in routine airway management: a

       randomised, controlled clinical trial. Anaesthesia2006; 61: 1093-9.

5.     Maharaj CH, Buckley E, Harte BH, et al. Endotracheal intubation in patients with

         cervical spine immobilization. Anesthesiology 2007; 107: 53-9.