Incision and drainage
Patients in the incision and drainage arm were admitted in the Emergency ward and prepared for surgery under general anesthesia in casualty theatre by the principal investigator. In the operation theatre with the patient positioned supine, the breast was swabbed using Chlorhexidine- Cetrimide (Cetrimide 15% w/v, Chlorhexine 1.5%w/v Isopropylalcohol4%w/v) 35 mls in 1 L of water. A skin depth incision was made at the area of maximum fluctuation along skin lines and a sinus forceps used to reach the abscess cavity. Initial pus was swabbed with a sterile pus swab which was transported for Culture and sensitivity. The pus was then evacuated and loculi broken down digitally, the wound was packed with sterile gauze. After recovery, the patient was taken back to emergency ward.
Post operatively the patient was put on analgesics and antibiotics, Diclofenac 75 mg i/m stat, then 50 mg orally for 3 days and Cloxacillin 500 mg 8hry for 10 days respectively. The patient was discharged home the next morning to undergo daily wound dressing at a nearby clinic until the wound heals. Patients whose culture and sensitivity results showed resistance to Cloxacillin were excluded from the study and the antibiotic treatment changed accordingly.
Ultrasound guided needle aspiration
Patients under the needle aspiration arm were managed in the department of Radiology Ultrasound room as outpatient cases. Under aseptic condition, a small area of skin adjacent to the abscess was anaesthetized by 1% Lignocaine through a 23 G needle. Aspiration was done under ultrasound guidance using a 16 G needle and a 20 mls syringe. Initial aspirated pus was sent for culture and sensitivity. Aspiration was done until there was no significant residual pus. After the procedure the patient was discharged on antibiotics and analgesics, Cloxacillin 500 mg orally 8hry for 10 days and Diclofenac 75 mg i/m stat then 50 mg orally 8hry for 3 days respectively. Similarly patients whose culture and sensitivity results showed resistance to Cloxacillin were excluded from the study and the antibiotic treatment changed accordingly.
In order to minimize non- compliance to treatment in both arms, drugs were provided by the principal investigator to the patients who could not afford buying the drugs. Patients were required to come back with the packs of drugs during follow up visits to countercheck whether the patients had taken the drugs. In both arms, lactating patients were advised to resume breast-feeding on both breasts as soon as possible as they could tolerate the pain as the baby breast feed. The patient's follow up was done at the OPD by the principal investigator on day 7, day 14 and 30 days. At every follow up, clinical assessment of symptoms and signs was done to assess resolution of the abscess.
Ultrasound scan was done to assess radiological resolution of the abscess which was defined as complete absence of fluid collection, normal breast glandular and fibro fatty tissues without edema. In situation where the abscess persisted in case of ultrasound guided needle aspiration, re-aspiration was to be done on day 7, if it still persisted on day 14 it was considered treatment failure and hence converted to the traditional incision and drainage.
Breast abscess recurrence and acceptance were assessed at the last visit (day 30). Patients who had not achieved complete resolution of the breast abscess at the end of the study period were referred to the Breast outpatient clinic for further follow up.
All costs were done in Ugandan shillings. Costs incurred by the patients and they included; cost for antibiotics, analgesics, syringes (20 cc) and cannulas (FG 16) used during U.S.S guided aspiration. These were estimated basing on open market price obtained in the local pharmacies. Costs for lodging, professional fee, surgery, anesthesia, amenities, sundries, doctor in care fee and health care fee were estimated basing on the Mulago hospital private patients' charges for the year 2007. Cost for ultrasound guided aspiration was valued basing on the charges as per radiology department for interventional ultrasound guided procedures. Costs for daily dressing for patients in the incision and drainage group was obtained from patient basing on how much she was charged every time she would go for wound dressing at the nearby clinic.
Data collection and statistical analysis
Data was collected using a structured and coded interviewer administered questionnaire. Administered in the questionnaire were; Age, Parity, Social economic status, Smoking, Time of presentation from onset of symptoms and Size of breast abscess. Outcome variables included; Time to breast abscess resolution, Breast abscess recurrence, Acceptance of ultrasound guided needle aspiration procedure and Cost of the procedures. Statistical analysis was done using SPSS computer software version 11.5. Categorical data was summarized into proportions, percentages and rates. Continuous data was summarized into mean, median, mode, range and standard deviation. Tables were used to present data. Chi-square was used to compare the differences between the two groups where the outcome was categorical and if continuous, t-test was used. Statistical significance was defined as a P value of less than 0.05. Survival Analysis using Kaplan-Meier and Cox Regression was used to compare the healing rates between the two groups. For the cost data, costs in each intervention arm were summed up to give the total expenditure per intervention. The cost effectiveness ratio was determined by dividing the total cost of each intervention group by the number of patients successfully treated.
Approval to carry out research was obtained from; Faculty of Medicine Research Committee, National Science and Research Council, Mulago Hospital Complex and the department of surgery, Mulago hospital before the commencement of the study.