Pneumothorax following ultrasound guided supraclavicular brachial plexus block.

Sir,

I read with keen interest the article “Pneumothorax following ultrasound guided supraclavicular brachial plexus block”.[1] The authors have very vividly illustrated the ways to avoid this potentially lethal and one of the most dreaded complications but I would like to add a couple of points.

It's very important that before we start needling for the supraclavicular block we get the subclavian artery and the plexus to lie over the 1st rib rather than pleura. Slight posterior inferior angulation of the ultrasound probe helps in obtaining this ultrasound picture. The advantage of getting the plexus over the 1st rib is that even if the view of needle is missed as it was in this particular case there would be more chance that needle would be hitting the rib which acts a natural barrier before hitting the pleura.

The clear understanding of the difference in appearance of 1st rib and pleura is of utmost importance.

At times it is very difficult to get the plexus over the 1st Rib due to specific neck and shoulder anatomy. These are the patients wherein we have to be very careful. An alternative method of putting the probe in the anterior posterior direction rather than parallel to the clavicle has been described and helps in getting the plexus over the 1st rib and helps in decreasing the risks of pneumothorax.[23]

Tall, thin patients seem to be at a greater risk and the risk is greater on the right side as the cupola of the lung is higher on right side[2] as was the in this case.

The bottom line always remains that make sure what you are seeing is the tip of the needle and do not advance the needle till you can actually see it.