Risk factors for postcesarean surgical site infection

Reduction of surgical site infections after Caesarean delivery using surveillance

Since 1997, the Krankenhaus Infektions Surveillance System (KISS) has collected data on surgical site infections (SSIs) following Caesarean delivery (CD). The aim of this study was to determine whether surveillance and feedback of healthcare-associated infections (HAIs) could reduce the infection rate after CD. Only departments that had participated in KISS for at least three years were included in the analysis. The CD infection rates of the first, second and third years of KISS participation were compared for significant differences. The relative risk was calculated for the first and the third year of KISS participation. Multi-variate logistic regression analysis was performed to detect significant risk factors for SSI after CD using the third year of participation as one parameter. Twenty-six of 52 obstetric and gynaecology departments met the study's inclusion criteria. In those 26 departments, 17,405 CD procedures were performed and 331 SSIs were recorded (1.9%). The SSI rate after CD procedures was significantly reduced in the third year of KISS participation (1.6%) compared with the first year of KISS participation (2.4%), with a relative risk of 0.63 [95% confidence interval (CI) 0.48-0.82]. Logistic regression analysis confirmed that KISS participation over three years was an independent factor for the reduction of SSI rate (odds ratio 0.64; 95% CI 0.49-0.83). As shown previously for other types of HAI, this study demonstrated that continuous surveillance and comparison with stratified reference data could reduce SSI infection rates after CD.

Postpartum endometritis

Postpartum endometritis or a surgical site infection should be suspected if the patient develops an elevated oral temperature, 100.4 degrees F or higher, with an associated tachycardia following the procedure. A tachycardia paralleling the temperature strongly indicates infection. A thorough examination should be performed. Patients failing to respond to initial antibiotic therapy should be thoroughly evaluated for the possible emergence of a resistant bacterium or the development of an abscess or septic pelvic thrombosis. Antibiotic therapy should be continued until the patient is afebrile for 24 to 48 hours, the white blood cell count returns to normal, and the patient is tolerating oral liquids and solids, and ambulating without difficulty.

Risk factors for post-partum complications occurring after preeclampsia and HELLP syndrome. A study in 453 consecutive pregnancies

OBJECTIVE

To evaluate complications that occurred during the post-partum period for patients with preeclampsia or HELLP syndrome.

STUDY DESIGN

Retrospective analysis of 453 patients. The main outcome measures were maternal complications during post-partum period: fever >38.5 degrees C with proved infection, abdominal or perineal abscess, thrombo-embolic events, reoperation, need for blood transfusion, acute renal failure, eclampsia or disseminated intravascular coagulation. Statistic tests included univariate and multivariate analysis with stepwise descending logistic regression.

RESULTS

Patients were divided into 305 preeclampsia (67.3%) and 20 HELLP syndrome (4.4%), 128 (28.3%) had both. Eighty-five patients (18.8%) had at least one post-partum complication. The most frequent complication was infection: fever (41 patients, 9.1%) and abscess (30 patients, 6.6%). Twenty-six transfusions (5.7%), 10 disseminated intravascular coagulation (2.2%), seven thromboembolic events (1.5%), seven reoperations (1.5%) and one eclampsia (0.2%) were observed. There was no acute renal failure, no pulmonary oedema and no maternal death. Stepwise logistic regression showed five independent risk factors associated with post-partum complications: ascites or pulmonary oedema (OR: 1.84, 95% CI: 1.01-3.37), platelet count <100000/mm3 (OR: 1.96, 95% CI: 1.18-3.26), serum acid uric >360 micromol/l (OR: 2.36, 95% CI: 1.22-4.52), serum creatinine >120 micromol/l (OR: 2.99, 95% CI: 1.32-6.78), and proteinuria >5 g/l (OR: 1.80, 95% CI: 1.06-3.05).

CONCLUSION

We conclude that severity criteria for preeclampsia or HELLP syndrome combined with caesarean section increased the risk of complication during the post-partum period.

Maternal obesity and complications during pregnancy

Obesity has become a major health problem all over the world and during pregnancy is associated with an increased risk of complications, including gestational diabetes, preeclampsia, and delivery complications such as macrosomia, shoulder dystocia and higher rates of cesarean sections and infections. Maternal obesity may also be an independent risk factor for neural tube defects and fetal mortality. This review focuses on the consequences of maternal obesity during pregnancy.

Infections de site opératoire chez les patientes césarisées : bilan de 5 années de surveillance

AIMS

To determine the incidence of surgical site infections and to identify risk factors for infections.

METHOD

A prospective study of surgical site infections (SSI) after cesarean section was carried out from September 1997 to September 1998 (pilot study) and from January 2000 to August 2003, using the methodology of the American National Nosocomial Infection Surveillance System. Follow up of women was performed by midwives until discharge and during the post-natal visit. Suspected surgical site infections were confirmed by surgeons and infection control practitioners. The microbiological file of each patient was edited 30 days after cesarean section. Risk factors were analyzed using a logistic regression model.

RESULTS

During the pilot study, infection rate was estimated at 3.2%. At multivariate analysis, factors independently associated with an increased risk of SSI were ASA score > 1, performance of cesarean section in a room not dedicated to this activity, and use of an open urine drainage system. During the following years (2000-2003), infection rates progressively decreased to reach 1.9% in 2003. Infections included superficial wound infections (involving skin and subcutaneous tissue) (47%), deep wound infections (involving deep and soft tissue (fascia and muscle) (20%) and organ/space infections (i.e. endometritis, pelvic abscess) (33%). Infections occurred after patient discharge in 47.5% of cases and diagnosis was based only on clinical findings in 30% of cases. Infected patients were hospitalized longer (median: 6 days) than non infected patients.

CONCLUSION

Prospective surveillance of SSI led to better awareness of infectious problems among health care workers, to identification of risk factors and evaluation of health procedures. Surveillance contributed to a decrease in nosocomial infections.

The Maternal-Fetal Medicine Units cesarean registry: chorioamnionitis at term and its duration-relationship to outcomes

OBJECTIVE

The purpose of this study was to evaluate the relationship between chorioamnionitis and its duration to adverse maternal, fetal, and neonatal outcomes.

STUDY DESIGN

This was a 13-university center, prospective observational study. All women at term carrying a singleton gestation who underwent primary cesarean from January 1, 1999 to December 31, 2000 were eligible. Data abstraction was systematic and performed by trained research nurses. Selected adverse outcomes were compared between pregnancies with, and without, clinically diagnosed chorioamnionitis using relative risks (RRs) and 95% CIs. The duration of chorioamnionitis was stratified into 5 intervals (<or=3 h,>3-6 h,>6-9 h,>9-12 h, and>12 h), and respective outcomes compared by Mantel-Haenszel test for trend. Additionally, regression analysis was used to compute odds ratios (ORs) and 95% CIs for chorioamnionitis duration length as a continuous explanatory variable.

RESULTS

16,650 pregnancies were analyzed, 1965 (12%) with chorioamnionitis, which was associated with significantly increased risks of maternal blood transfusion, uterine atony, septic pelvic thrombophlebitis, and pelvic abscess (RR 2.3-3.7), as well as 5-minute Apgar <or=3, neonatal sepsis, and seizures (RR 2.1-2.8). By test of trend, only uterine atony (P <.01), maternal blood transfusion (P=.03), maternal admission to intensive care unit (P=.02), and 5-minute Apgar <or=3 (P <.01) were associated with duration of chorioamnionitis. By logistic analysis, only uterine atony (OR for each hour of chorioamnionitis 1.03, 95% CI 1.00-1.06), 5-minute Apgar <or=3 (OR 1.09, 95% CI 1.00-1.16), and neonatal mechanical ventilation within 24 hours of birth (OR 1.07, 95% CI 1.01-1.12) were significantly associated with chorioamnionitis duration.

CONCLUSION

Chorioamnionitis was associated with increased rates of morbidity after cesarean at term. The duration of chorioamnionitis, however, was not related to most measures of adverse maternal or fetal-neonatal outcome.

Complications of cesarean deliveries: rates and risk factors

OBJECTIVE

The purpose of this study was to determine complication rates after cesarean delivery and to identify independent risk factors for complications.

STUDY DESIGN

In a prospective population-based cohort study in Norway, rates of predefined types of complications from 2751 cesarean deliveries were determined. The complications that were studied were intraoperative complications, blood loss, wound infection, cystitis, endometritis, hematoma, and reoperation. Independent risk factors were identified by stratification and multiple logistic regression analysis.

RESULTS

Altogether, 21.4% of the women had > or =1 complications. The degree of cervical dilation, general anesthesia, low gestational age, and fetal macrosomia were independent risk factors. For operations that were performed at 9 to 10 cm cervical dilation, the complication rate was 32.6% versus 16.8% at 0 cm (odds ratio, 2.39; 95% CI, 1.77-3.22; P<.001).

CONCLUSION

Cesarean delivery was associated with a high complication rate. Increasing cervical dilation and, in particular, cervical dilation of 9 or 10 cm at the time of operation, general anesthesia, low gestational age, and fetal macrosomia were identified as independent risk factors.

Obstetricians' attitudes, subjective norms, perceived controls, and intentions on antibiotic prophylaxis in caesarean section

Over 10% of current births in all countries of the world are delivered by caesarean section. Single-dose ampicillin or cefazolin administered after cord clamping has been proven to be effective for the prevention of post-caesarean infections as indicated in many randomised trials and reviews in the Cochrane Library. This study aimed to determine three determinants of behavioural intention using the theory of planned behaviour: attitudes, subjective norms, and perceived controls. Intentions were examined for five aspects of the use of antibiotic prophylaxis, namely whether or not antibiotics were used, used in all caesarean sections, after rather than before cord clamping, whether ampicillin/cefazolin or broader-spectrum antibiotics were used, and whether single or multiple doses were given. Fifty obstetricians selected from university, regional, and general hospitals in southern Thailand, were surveyed using a questionnaire and in-depth interview. Their intentions to use a single dose and to use in all cases were low, and this was related to negative attitudes and reference groups who did not approve of the single dose. The negative attitude was based on scepticism concerning the applicability of well-equipped trials from the developed world and fear of consequences of post-caesarean infections. Norms carried over from residency training had more long-term influence in their practice than newer information from books or journals. Perceived external controls on their practice were less predictive of intentions. Intentions were only partly predictive of behaviour. Changing attitudes, introducing evidence-based information into residency training and strengthening control systems in the hospital are essential to improve intentions.

Subcutaneous stitch closure versus subcutaneous drain to prevent wound disruption after cesarean delivery: a randomized clinical trial

OBJECTIVE

The purpose of this study was to compare a subcutaneous stitch closure and subcutaneous drain placement for the risk of wound disruption after cesarean delivery.

STUDY DESIGN

This was a prospective randomized clinical trial that evaluated subcutaneous stitch closure, placement of a subcutaneous drain, or no closure for subsequent wound disruption risk in women with subcutaneous depth at >or=2 cm.

RESULTS

The maternal demographics and intrapartum risk factors for postoperative wound disruptions were similar among the 964 study subjects, who were divided into 3 groups. Wound disruptions that required opening of the wound, irrigation, debridement, packing, and/or secondary delayed closure occurred in 9.7% of the women with no closure, 10.4% of the women in the stitch closure group, and 10.3% of the women in the closed drain group (P =.834).

CONCLUSION

There appears to be no difference in the subsequent risk of wound complications when no closure of the subcutaneous tissue layers occurs versus suture closure or a closed drainage system.