**11. Conclusion**

Although it has been suggested by many to be the era of ultrasound in regional anaesthesia, it could equally be termed the era of the tissue plane. This of course is courtesy of ultrasound, but the technology alone will not get us the results we want. It has been suggested that 'if we can see it, we can block it' [84], but this invites invocation of the old adage 'primum non nocere'. Was the block necessary? Did it add real benefit? All interventions risk harm. Perhaps we could change the saying to 'now that we can see it, how do we better understand what we are seeing, and how can this aid our practice?' The challenge is to methodically and responsibly work our craft so that it helps us as well as our patients.
