Women (18+, American Society of Anesthesiologists 1,2,3) undergoing a mastectomy with axillar procedure will be randomised and receive a ultrasound guided modified pectoral nerve block, if participants meet in- and exclusion criteria and provide written informed consent.
Using a two needle approach, ten milliliters of local anesthetic is injected under ultrasound guidance between the major and minor pectoral muscle and twenty milliliters between the minor pectoral and the serratus anterior muscle, on the side to be operated.
Participants receive intravenous Patient Controlled Analgesia with morphine and dehydrobenzperidol (1mg/ml morphine, 50µg dehydrobenzperidol/ml).
Furthermore every participant in the trial will receive ketorolac 0.5mg/kg three times a day and paracetamol four times 1g per day.
When the analgesia using the intravenous Patient Controlled Analgesia regime isn't sufficient, the anesthesiologist will titrate with morphine until pain free using a protocol (a bolus of 2mg morphine IV every ten minutes until pain free).
