A 27 or 30G insulin needle with some lidocaine (still often called lignocaine here in Australia ) is a nice addition to this procedure. I rarely omit it unless the patient is unconscious. If you inject the local anaesthetic under real time ultrasound, it can also serve as a seeker so you see if you’re off target with the 30G needle and adjust based on that information, which improves your success with the larger (commonly 22G) needle used to take the gas. Not unreasonable to request local anaesthetic, really - it is known to be a painful procedure.