title: Effect of the menstrual cycle phase on post-operative pain perception and analgesic requirements.
abstract: BACKGROUND
  Research has shown that menstrual cycle phase may affect pain sensitivity. There is a lack of studies evaluating this effect on post-operative pain and analgesic needs.
  
  
  METHODS
  In this prospective cohort study, we determined the effect of menstrual cycle phase on pain perception and analgesic requirements following total abdominal hysterectomy. Sixty women with regular menstrual cycles undergoing elective surgery were recruited and divided into 'follicular' and 'luteal' groups according to their menstrual history. Post-operative pain was managed with intravenous patient-controlled analgesia using tramadol. Intravenous morphine was used for rescue analgesia, and pain was assessed for 24 h.
  
  
  RESULTS
  Pain scores in the recovery room and ward six and 24 h post-operatively were similar in the groups at rest and on coughing. Pain scores at rest 12 h post-operatively were significantly higher in the luteal group (P = 0.043), while they were similar on coughing. There was no significant difference in the total tramadol requirement. Number of patients requiring rescue analgesia and the amount of morphine used was also similar.
  
  
  CONCLUSIONS
  There was no difference in pain scores or analgesic requirements between the two groups except for rest pain at 12 h, which was significantly higher in the luteal group. As pain was assessed at 13 different time points, a significant difference seen only at one point could be due to random chance. We suggest that future research should concentrate on studying this issue in patients of relatively younger age groups with more pronounced hormonal variations during the cycle.
authors.affiliation: Department of Anaesthesia, Aga Khan University, Karachi, Pakistan. aliya.ahmed@aku.edu
authors.forename: A
authors.initials: A
authors.lastname: Ahmed
authors.forename: F
authors.initials: F
authors.lastname: Khan
authors.forename: M
authors.initials: M
authors.lastname: Ali
authors.forename: F
authors.initials: F
authors.lastname: Haqnawaz
authors.forename: A
authors.initials: A
authors.lastname: Hussain
authors.forename: S I
authors.initials: SI
authors.lastname: Azam
mesh_terms: D000328:Adult; D016058:Analgesia, Patient-Controlled; D000700:Analgesics / Q000008:administration & dosage* / Q000627:therapeutic use*; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000627:therapeutic use; D001794:Blood Pressure / Q000502:physiology; D003371:Cough / Q000150:complications; D004562:Electrocardiography; D004958:Estradiol / Q000097:blood; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007432:Intraoperative Period; D008597:Menstrual Cycle / Q000502:physiology*; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy* / Q000523:psychology*; D011374:Progesterone / Q000097:blood; D011997:Recovery Room; D056152:Respiratory Rate; D014147:Tramadol / Q000008:administration & dosage / Q000627:therapeutic use
chemical_list: D000700:Analgesics; D000701:Analgesics, Opioid; D014147:Tramadol; D011374:Progesterone; D004958:Estradiol; D010100:Oxygen