Post Caesarean Surgical Wound Infection in Obese Patients: An Open Prospective Cohort Study

Abstract

Background:Studies have linked intra-abdominal hypertension (IAH) to postoperative infectious complications. Since IAH is a constant companion of obesity, it is logical to assume a causal connection between high incidences of wound infection in female obese patients to the level of postoperative intra-abdominal pressure (IAP).

Objective:The primary aim of the study was to determine if wound infection in obese primigravidas is related to intra- abdominal pressure (IAP) after caesarean section. Secondary objective was to determine the type of bacterial contamination in placenta, lochia and surgical site.

Materials and methods:Inclusion criteria were all primigravida women with term singleton pregnancy and delivery by caesarean section. A total of 313 patients were divided into four groups according to their BMI recorded before sixth week of pregnancy. Group I (n=90): BMI 18.5 - 24.9, Group II (n=137): BMI 25-29.9, Group III (n=49): BMI 30-39.9, Group IV (n=37) BMI ≥ 40 kg/m2.

Postoperatively incision site was evaluated for oedema, flushing, scar tenderness, hyperthermia, purulent discharge, and suture line disruption. Discharge was sent for cytology. The presence of seroma and hematomas (non-infectious complications) was assessed by ultrasound in uterovesical fold, subaponeurotic and epiaponeurotic layer done on post operative three, ï¬ve and seven days. Bacteriological studies were carried out on amniotic fluid, placenta, lochia and wound discharge. IAP was assessed by UnometerTM Abdo-PressureTM (Unomedical). Difference in abdominal pressure (Δ IAP) from baseline at 12, 24 and 72 hours was calculated.

Results:Postoperative wound complications (including infectious and non-infectious) was seen in 56 (17.9 %) post caesarean patients. Epiaponeurotic seroma, subaponeurotic and epiaponeurotic hematoma, infected wound and bacterial contamination of postoperative wounds was statistically signiï¬cant in obese patients (group III & group IV) compared to non obese group I (p < 0.05). The titer of cultured microorganisms increased with higher degree of obesity, but did not exceed 105 CFU/ml, cut off for infective wound. Postoperative IAP decreased with time in all groups. However IAP was statistically higher in Groups II, III and IV compared to Group I at all stages of the study.

Conclusion: In the present study, wound infection occurred in 9.9% obese female following caesarean section. Long- persisting IAH in the postoperative period is a signiï¬cant risk factor for post caesarean wound infection.

Keywords: Obesity; C-section; Wound infection; Intra-abdominal pressure; Bacteriological test