Prospective Cohort Study Assessing Chronic Pain in Patients With Thoracic Blocks Following Minor Surgery for Breast Cancer.

This is a prospective observational study assessing the interest of preoperative thoracic block (injection of local anesthetic around the serratus muscle under ultrasound guidance) in the prevalence of chronic pain 3 months after a conservative breast cancer surgery.

Information on the present survey was given during pre-operative consultation and signed informed consent was obtained to enter the study.

The management of patients undergoing minor surgery for breast cancer is standardized within our department and reported in our previous study. After starting the induction of anesthesia and insertion of a laryngeal mask, a regional analgesia technique was performed under ultrasonography. Twenty ml of ropivacaine 3.75mg/ml were injected under the serratus muscle, at the lateral edge of the minor pectoralis muscle. In the absence of contraindications, multimodal analgesia consisted of paracetamol, non-steroidal anti-inflammatory drugs and nefopam. Postoperative intravenous morphine titration was possible in patients presenting a pain score >3/10 (numeric pain intensity scale from 0 = no pain to 10 = maximum imaginable pain) in the recovery room. If 0.1mg/kg of morphine did not permit to alleviate pain, ketamine titration was initiated by the anesthesiologist.

The incidence of patients that required opioids titration in the recovery room (and the dose injected) was recorded.

The questionnaire sent to the patients 3 months after their surgery was mainly composed of closed questions. This questionnaire included pain score, location of pain, analgesic drugs consumption, neuropathic component (self-administered questionnaire derived from the Neuropathic Pain 4 Questions - DN4 questionnaire), impact of quality of life using the Brief Pain Inventory.