Thermal territories of the abdomen after caesarean section birth: infrared thermography and analysis.
OBJECTIVE
To develop and refine qualitative mapping and quantitative analysis techniques to define 'thermal territories' of the post-partum abdomen, the caesarean section site and the infected surgical wound. In addition, to explore women's perspectives on thermal imaging and acceptability as a method for infection screening.


METHODS
Prospective feasibility study undertaken at a large University teaching hospital, Sheffield UK. Infrared thermal imaging of the abdomen was undertaken at the bedside on the first two days after elective caesarean section. Target recruitment: six women in each of three body mass index (BMI) categories (normal, 18.5-24.9 kg/m²; overweight 25-29.9 kg/m²; obese ≥30 kg/m²). Additionally, women presenting to the ward with wound infection were eligible for inclusion in the study. Perspectives on the use of thermal imaging and its practicality were also explored via semi-structured interviews and analysed using thematic content analysis.


RESULTS
We recruited 20 women who had all undergone caesarean section. From the booking BMI, eight women were obese (including two women with infected wounds), seven women were overweight and five women had a normal BMI. Temperature (ºC) profiling and pixel clustering segmentation (hierarchical clustering-based segmentation, HCS) revealed characteristic features of thermal territories between scar and adjacent regions. Differences in scar thermal intensity profiles exist between healthy scars and infected wounds; features that have potential for wound surveillance. The maximum temperature differences (∆T) between healthy skin and the wound site exceed 2º C in women with established wound infection. At day two, two women had a scar thermogram with features observed in the 'infected' wound thermogram.


CONCLUSIONS
Thermal imaging at early and later times after caesarean birth is feasible and acceptable. Women reported potential benefits of the technique for future wound infection screening. Thermal intensity profiling and HCS for pixel cluster dissimilarity between scar and adjacent healthy skin has potential as a method for the development of techniques targeted to early infection surveillance in women after caesarean section.
Professor of Clinical Science, Midwifery Researcher, Professor of Maternal and Infant Health, Centre for Health and Social Care Research, Sheffield Hallam University, Montgomery House, 32 Collegiate Crescent, Sheffield.
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C
Childs
ST7 Obstetrics and Gynaecology, Consultant, Jessop Wing, Sheffield Teaching Hospital NHS Trust, Tree Root Walk, Sheffield.
M R
MR
Siraj
Professor of Clinical Science, Midwifery Researcher, Professor of Maternal and Infant Health, Centre for Health and Social Care Research, Sheffield Hallam University, Montgomery House, 32 Collegiate Crescent, Sheffield.
F J
FJ
Fair
Associate Lecturer, Materials and Engineering Research Institute, Sheffield Hallam University, Howard Street, Sheffield.
A N
AN
Selvan
Professor of Clinical Science, Midwifery Researcher, Professor of Maternal and Infant Health, Centre for Health and Social Care Research, Sheffield Hallam University, Montgomery House, 32 Collegiate Crescent, Sheffield.
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H
Soltani
EPSRC Research Fellow, University of Sheffield, Portobello Centre, Sheffield.
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J
Wilmott
ST7 Obstetrics and Gynaecology, Consultant, Jessop Wing, Sheffield Teaching Hospital NHS Trust, Tree Root Walk, Sheffield.
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T
Farrell
D000005:Abdomen / Q000601:surgery*; D000328:Adult; D015992:Body Mass Index; D002585:Cesarean Section; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007407:Interviews as Topic; D049590:Postpartum Period; D011247:Pregnancy; D011446:Prospective Studies; D013530:Surgical Wound Infection / Q000175:diagnosis* / Q000517:prevention & control; D013817:Thermography / Q000379:methods*
abdomen; caesarean section; infection surveillance; infrared thermography; surgical site infection; thermal imaging