In September 2006, members of the Sex, Gender and Pain Special Interest Group of the International Association for the Study of Pain met to discuss the following: (1) what is known about sex and gender differences in pain and analgesia; (2) what are the “best practice” guidelines for pain research with respect to sex and gender; and (3) what are the crucial questions to address in the near future? The resulting consensus presented herein includes input from basic science, clinical and psychosocial pain researchers, as well as from recognized experts in sexual differentiation and reproductive endocrinology. We intend this document to serve as a utilitarian and thought-provoking guide for future research on sex and gender differences in pain and analgesia, both for those currently working in this field as well as those still wondering, “Do I really need to study females?”

Summary

Objectives

A shortfall exists of female doctors in senior academic posts in the United Kingdom. Career progression depends on measures of esteem, including publication in prestigious journals. This study investigates gender differences in first and senior authorship in six peer-reviewed British journals and factors that are associated with publication rates.

Design and main outcome measures

Data was collected on United Kingdom first and senior authors who had published in the British Medical Journal, Lancet, British Journal of Surgery, Gut, British Journal of Obstetrics and Gynaecology and the Archives of Diseases in Childhood. Authorship and gender were quantified for 1970, 1980, 1990, 2000 and 2004 (n=6457). In addition, selected questions from the Athena Survey of Science Engineering and Technology (ASSET2006), web-based doctor's self-report of publications were also analysed (n=1162).

Results

Female first authors increased from 10.5% in 1970 to 36.5% in 2004 (p<0.001) while female senior authors only increased from 12.3% to 16.5% (p=0.046). Within individual journals, the largest rise was in British Journal of Obstetric and Gynaecology with 4.5- and 3-fold increases for first and senior authors, respectively. In contrast, female senior authors marginally declined in Gut and Lancet by 2.8% and 2.2%, respectively. ASSET2006 identified that female respondents who were parents were less likely to have publications as sole (p=0.02) and joint authors (p<0.001) compared to male respondents. Female respondents with care responsibilities for parents/partner also had less publications as lead authors compared to those without carer responsibilities (p<0.001).

Conclusion

The increase in UK female first authors is encouraging. In contrast, there is considerable lag and in some specialties a decline in female senior authors. Factors that could narrow the gender gap in authorship should be sought and addressed.

Background

Breast pain and tenderness affects 70% of women at some time. These symptoms have been attributed to stretching of the nerves with increase in breast size, but tissue mechanisms are poorly understood.

Methods

Eighteen patients (n = 12 breast reduction and n = 6 breast reconstruction) were recruited and assessed for breast pain by clinical questionnaire. Breast skin biopsies from each patient were examined using immunohistological methods with specific antibodies to the capsaicin receptor TRPV1, related vanilloid thermoreceptors TRPV3 and TRPV4, and nerve growth factor (NGF).

Results

TRPV1-positive intra-epidermal nerve fibres were significantly increased in patients with breast pain and tenderness (TRPV1 fibres / mm epidermis, median [range] – no pain group, n = 8, 0.69 [0–1.27]; pain group, n = 10, 2.15 [0.77–4.38]; p = 0.0009). Nerve Growth Factor, which up-regulates TRPV1 and induces nerve sprouting, was present basal keratinocytes: some breast pain specimens also showed NGF staining in supra-basal keratinocytes. TRPV4-immunoreactive fibres were present in sub-epidermis but not significantly changed in painful breast tissue. Both TRPV3 and TRPV4 were significantly increased in keratinocytes in breast pain tissues; TRPV3, median [range] – no pain group, n = 6, 0.75 [0–2]; pain group, n = 11, 2 [1-3], p = 0.008; TRPV4, median [range] – no pain group, n = 6, [0–1]; pain group, n = 11, 1 [0.5–2], p = 0.014).

Conclusion

Increased TRPV1 intra-epidermal nerve fibres could represent collateral sprouts, or re-innervation following nerve stretch and damage by polymodal nociceptors. Selective TRPV1-blockers may provide new therapy in breast pain. The role of TRPV3 and TRPV4 changes in keratinocytes deserve further study.

A new classification for caesarean section was developed in a two-part study conducted at six hospitals. Initially, 90 anaesthetists and obstetricians graded ten clinical scenarios according to five different classification methods--visual analogue scale; suitable anaesthetic technique; maximum time to delivery; clinical definitions; and a 1-5 rating scale. Clinical definitions was the most consistent and useful, and this method was then applied prospectively to 407 caesarean sections at the same six hospitals. There was close agreement (86%) between anaesthetists and obstetricians for the five-point scale (weighted kappa 0.89), increasing to 90% if two categories were combined (weighted kappa 0.91). We suggest that the resultant four-grade classification system--(i) immediate threat to life of woman or fetus; (ii) maternal or fetal compromise which is not immediately life-threatening; (iii) needing early delivery but no maternal or fetal compromise; (iv) at a time to suit the patient and maternity team--should be adopted by multidisciplinary groups with an interest in maternity data collection.

The development of a cancer support organisation, CancerCare, for North Lancashire and South Lakeland is described. The use of relaxation therapy is described to illustrate the demand for supportive care. Between January 1990 and 1991, 513 patients, 243 relatives and 143 bereaved were referred to five cancer support nurses. One hundred and sixty-two (32%), 29 (12%) and 49 (34%) respectively, used relaxation therapy. The high demand for supportive care suggests that services should be made available in any district health provider unit. Measures of benefit and better definition of services are required before clear recommendations can be made.

The functions of an outpatient anaesthetic clinic are discussed in relation to the first 100 patients who attended. Preoperative assessment excluded 11 patients who would have been refused anaesthesia for elective operations without further treatment. Six of these required preoperative physiotherapy, 4 antihypertensive therapy, and 1 hospital admission for incipient myocardial infarction. The clinic also played an important role with regard to advice and reassurance of the patient from an experienced anaesthetist, organising suitable admission dates, and detecting anaesthetic and surgical hazards, especially dental caries and obesity, which could be corrected before operation. Two patients developed postoperative complications which could not have been foreseen.

Observations were made on 26 infants delivered by elective caesarean section under general anaesthesia. A standard anaesthetic technique was employed using a methohexitone, relaxant, nitrous oxide-oxygen sequence with regulated ventilation and the administration of papaveretum after clamping the umbilical cord. In 12 patients the induction dose of methohexitone was 1·4mg/kg and in 14 it was reduced to 1·0 mg/kg. There were no significant differences between the two groups in the clinical status of the mothers, in operative technique and timing, or in the value of PO2, PCO2, and pH in the umbilical cord venous blood.

The infants whose mothers received the lower dose of methohexitone were in better condition, as assessed by the number needing assisted ventilation, the time taken to establish regular respiration, the Apgar score, and the “Apgar minus colour” score.

Measurements of closing volume have been made in 20 women between the 36th and 40th weeks of pregnancy. The patients were studied in the erect and supine positions and the point of airway closure was related to functional residual capacity. The results show that airway closure occurred during tidal ventilation in 10 patients in the erect position and in six patients in the supine position. These results may explain the variation found in maternal arterial oxygen tension during pregnancy.