title: Single-injection thoracic paravertebral block and postoperative analgesia after mastectomy: a retrospective cohort study.
abstract: BACKGROUND
  The treatment of postoperative pain after mastectomy is an area of increasing interest, as this treatment option is now considered a standard of care for those affected by breast cancer. Thoracic paravertebral nerve block (tPVB) using local anesthetics administered before mastectomy can theoretically provide postoperative analgesia, thereby facilitating a more comfortable and shorter hospitalization.
  
  
  METHODS
  In this retrospective cohort study, we aimed to determine the duration and degree to which tPVB provides postoperative analgesia in patients who underwent either unilateral or bilateral mastectomy (n = 182). We retrospectively examined the numeric rating scale (NRS) for pain scores recorded by nursing staff throughout individual patient hospitalizations, looking specifically at the following time points: arrival from the postanesthesia care unit to the surgical wards, noon on postoperative day 1 (POD1), and discharge. We also examined the number of days until patients were discharged from the hospital.
  
  
  RESULTS
  Our results revealed a statistically significant decrease in NRS in pain scores for patients who had received a tPVB (n = 92) on arrival from the postanesthesia care unit to the surgical wards (mean NRS decrease of 1.9 points; 99% confidence interval [CI], -3.0 to -0.8; P < .001) but did not show statistically significant decreases in NRS for pain scores for patients at noon on POD1 (mean NRS decrease of 0.3 points at noon on POD1, P = .43) or at discharge (mean NRS decrease of 0.1 point at discharge, P = .65). Moreover, use of tPVB did not have an impact on time until discharge (average decrease of 0.5 hours; 95% CI, -6 to +5 hours, P = .87).
  
  
  CONCLUSIONS
  Single-injection tPVB appears to provide meaningful postoperative analgesia in the immediate postoperative period after mastectomy but not after the first day of surgery.
authors.affiliation: Department of Anesthesiology, University of California San Diego, San Diego, CA.
authors.forename: Rishi R
authors.initials: RR
authors.lastname: Agarwal
authors.affiliation: Department of Surgery, University of California San Diego, San Diego, CA.
authors.forename: Anne M
authors.initials: AM
authors.lastname: Wallace
authors.affiliation: Department of Anesthesiology, University of California San Diego, San Diego, CA.
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Madison
authors.affiliation: Department of Anesthesiology, University of California San Diego, San Diego, CA.
authors.forename: Anya C
authors.initials: AC
authors.lastname: Morgan
authors.affiliation: Departments of Quantitative Health Sciences and Outcomes Research, Cleveland Clinic, Cleveland, OH.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Mascha
authors.affiliation: Department of Anesthesiology, University of California San Diego, San Diego, CA. Electronic address: bilfeld@ucsd.edu.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Ilfeld
mesh_terms: D000328:Adult; D000368:Aged; D000779:Anesthetics, Local / Q000008:administration & dosage*; D001943:Breast Neoplasms / Q000601:surgery*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007902:Length of Stay; D008408:Mastectomy / Q000379:methods*; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy*; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D000779:Anesthetics, Local
keywords: Peripheral nerve block; Postoperative analgesia; Postoperative pain; Regional analgesia; Regional anesthesia