Case of the Month

Management:

Patient admitted to a general ward with standard and contact precautions (due to copious frank pus). The wound was locally infiltrated with Lignocaine, all stiches removed, and wound opened. Pus drained freely. A wound washout was done with saline. Daily saline dressings were prescribed. Antimicrobials prescribed:

·         Ampicillin 2g 6-hourly intravenously

·         Gentamycin 240mg daily intravenously

·         Metronidazole 400mg 8 hourly per mouth.

 Intravenous antimicrobials were stopped after 3 days and switched to oral antimicrobials. Patient discharged on 16 March 2022 in a satisfactory condition, wound clean and dry.  

Discussion:

Caesarean section is one of the most common surgical procedures performed and the incidence is increasing in all countries. South African caesarean rates are around 26.2% in the public sector, and almost three times that, 76.8% in the private sector.

Most studies done on caesarean section surgical site infections (SSI) come from sub-Saharan African countries.  In one study ⁷ the incidence of SSI was 7.3 % (range 1.7-10.4 %). Ninety-three percent of surgical site infections were superficial. In multivariate analysis, younger age, premature rupture of the membranes, and neonatal death were associated with an increased risk of surgical site infections (SSI). ⁷  Post-caesarean section wound complications may manifest themselves as bruises, seroma or dehiscence and wound infections may even present as necrotizing fasciitis in severe cases. ¹   Wound infection manifests itself with erythema and induration of the incision that usually develops 4 to 7 days after the cesarean section ^2,3. When the wound infection develops within 48 hours, the offending organisms are usually groups A or Beta-hemolytic Streptococcus. Other common pathogens isolated in wound infections are Ureaplasma urealyticum, Staphylococcus epidermidis, Enterococcus faecalis, Staphylococcus aureus, Escherichia coli and Proteus mirabilis. ⁴   It is always recommended that a tissue sample is taken after the wound is cleaned or in theatre during re-opening and debridement. In this case a superficial wound swab was taken and mixed growth isolated, which could indicate that the specimen was taken incorrectly. The diagnosis of the superficial incisional infection was still made according to clinical signs & symptoms.   

According to CDC a Superficial incisional surgical site infection (SSI) must meet the following criteria:

Date of event for infection occurs within 30 days after operative procedure (where day 1 = the procedure date) AND involves only skin and subcutaneous tissue of the incision AND patient has at least one of the following:

a.         purulent drainage from the superficial incision.

b.         organisms identified from an aseptically obtained specimen for purposes of clinical diagnosis or treatment

c.         superficial incision that is deliberately opened by a surgeon, attending physician

AND

d.         patient has at least one of the following signs or symptoms:

- pain or tenderness;

- localized swelling;

- erythema; or

- heat.

e.         diagnosis of a superficial incisional SSI by the surgeon or attending physician

www.cdc.gov/nhsn/xls/cpt-pcm-nhsn.xlsx 

Most risk factors for developing infection are known before delivery, and some are potentially modifiable. Although the incidence of surgical site infection decreased over time, targeted clinical and infection prevention and control interventions could further reduce the burden of illness associated with this health-care-related infection. Antibiotic prophylaxis is an established protective factor for surgical site infection. ⁵

In this case the patient received Cefazolin 2g intravenously less than 60 minutes prior to the time of skin incision. Numerous studies have shown a significant reduction in SSI rate in cesarean deliveries following implementation of an infection prevention bundle. Another bundle element is appropriate hair removal.  For many years, it has been known that the use of razors prior to surgery increases the incidence of wound infection when compared to clipping, depilatory use, or no hair removal at all. The use of clippers has been found to be the best method in many hospitals.

Adolescents are a particularly vulnerable group of the obstetric population. A study by Suna et al. aimed to determine the modifiable risk factors associated with surgical site infection (SSI) after cesarean section in adolescent pregnant patients. ⁶ This study was a retrospective case-control study looking at pregnant adolescents (≤ 19 years) who underwent caesarean section at an institution between January 2014 and March 2021. The diagnosis of SSI was made according to the criteria defined by the Centers for Disease Control and Prevention (CDC). Results: SSI was diagnosed in 62 (2.9%) of 2105 adolescent mothers who underwent cesarean section. Univariate and multivariate analyses confirmed that a high body mass index (BMI) (OR = 2.35; 95% CI, 1.3-4.78), induction of labor (OR = 1.9; 95% CI, 1.2-3.71), and pre-operative hemoglobin values less than 10 g/dl (OR = 2.1; 95% CI, 1.2-4.46) were risk factors for SSI in adolescent mothers. Conclusions: Body mass index (BMI), labour induction, and antenatal anemia were independent risk factors for SSI in adolescents. Among these, BMI and anemia were modifiable patient-related risk factors. Addressing obesity in adolescents and treating prenatal anemia could be the first steps toward preventing SSI. ⁶  

In this case the patient had a Hb = 10.5g/dl and labour were induced. She had a normal BMI.