Deep Block

The deep SAPB is performed with the same needle placement (see Figure 3). Ribs are seen as rounded structures with a bright hyper-echoic outline and black-out below this. The pleura is usually seen also as a bright hyper-echoic line sliding with respiration deep to the ribs. The needle is directed down onto the rib, taking care to avoid the pleura. It is then moved back slightly and local anaesthetic injected between the rib and serratus anterior muscle. This approach may be favourable in those with distorted anatomy secondary to rib fractures, or in the elderly where muscle layers may be poorly defined.