The mixed pectoral one / serratus plane block (PECI/SPB) block is another regional nerve block that has been successfully used by anesthesiologists at The Ottawa Hospital and offers a more complete pain blockade than the intercostal nerve block, as it includes more nerves that supply the breast. In addition to this, the intercostal nerve block is a so-called "blind-technique" compared to the PECI/SPB block, which is more accurately guided by ultrasound. Blind techniques are associated with higher failure rates.