PLoS One. 2016 May 10;11(5):e0155114. doi: 10.1371/journal.pone.0155114. eCollection 2016.
PURPOSE: Chronic pain after cesarean section (CS) is a serious concern, as it can result in functional disability. We evaluated the prevalence of chronic pain after CS prospectively at a single institution in Japan. We also analyzed perioperative risk factors associated with chronic pain using logistic regression analyses with a backward-stepwise procedure. MATERIALS AND METHODS: Patients who underwent elective or emergency CS between May 2012 and May 2014 were recruited. Maternal demographics as well as details of surgery and anesthesia were recorded. An anesthesiologist visited the patients on postoperative day (POD) 1 and 2, and assessed their pain with the Prince Henry Pain Scale. To evaluate the prevalence of chronic pain, we contacted patients by sending a questionnaire 3 months post-CS. RESULTS: Among 225 patients who questionnaires, 69 (30.7%) of patients complained of persistent pain, although no patient required pain medication. Multivariate analyses identified lighter weight (p = 0.011) and non-intrathecal administration of morphine (p = 0.023) as determinant factors associated with persistent pain at 3 months. The adjusted odds ratio of intrathecal administration of morphine to reduce persistent pain was 0.424, suggesting that intrathecal administration of morphine could decrease chronic pain by 50%. In addition, 51.6% of patients had abnormal wound sensation, suggesting the development of neuropathic pain. Also, 6% of patients with abnormal wound sensation required medication, yet no patients with persistent pain required medication. CONCLUSION: Although no effect on acute pain was observed, intrathecal administration of morphine significantly decreased chronic pain after CS.
BACKGROUND AND OBJECTIVES: Brazil ranks second among countries with the highest rates of cesarean section in the world. Little is known about the future consequences of this procedure on maternal health. This study investigated the influence of anesthetic/surgical technique and postoperative analgesia on the onset of chronic pain after three months of cesarean section. METHOD: This is a prospective randomized study of 443 patients undergoing cesarean section (elective and emergency), with different doses of hyperbaric bupivacaine 0.5% and opioids in spinal anesthesia. Patients were alocated into five groups as follow: G1 received hyperbaric bupivacaine (8 mg), sufentanil (2.5 μg), and morphine (100 μg); G2 received hyperbaric bupivacaine (10 mg), sufentanil (2.5 μg), and morphine (100 μg); G3 received hyperbaric bupivacaine (12.5 mg) and morphine (100 μg); G4 received hyperbaric bupivacaine (15 mg) and morphine (100 μg); G5 received hyperbaric bupivacaine (12.5 mg) and morphine (100 μg), without perioperative anti-inflammatory. Pain at rest and in movement were evaluated in the immediate postoperative period. Phone contact was made after three months of surgery for identification of patients withchronic pain. RESULTS: The incidence of chronic pain in the groups was G1=20%; G2=13%; G3=7.1%; G4=2.2%, and G5=20.3%. Patients who reported higher pain scores in the postoperative period had a higher incidence of chronic pain (p<0.05). CONCLUSION: The incidence of chronic pain decreases with higher doses of local anesthetics and use of anti-inflammatory drugs. The higher pain scores in the postoperative period were associated with chronic pain development after three months of cesarean section.