A multifaceted prevention program to reduce infection after cesarean section: Interventions assessed using an intensive postdischarge surveillance system

Perioperative Antibiotics and Other Factors Associated with Postcesarean Infections: A Case-Control Study

OBJECTIVE

Our objective was to determine modifiable risk factors associated with surgical site infection (SSI) and postpartum endometritis. We hypothesized that inappropriate surgical antibiotic prophylaxis would be a risk factor for both types of infections.

STUDY DESIGN

This was a single-center case-control study of SSI and endometritis after cesarean delivery over a 2-year period from 2016 to 2017. Cases were identified by International Classification of Diseases, 10th Revision diagnosis codes, infection control surveillance, and electronic medical records search and were subsequently confirmed by chart review. Three controls were randomly selected for each case from all cesareans ± 48 hours from case delivery. Demographic, pregnancy, and delivery characteristics were abstracted. Separate multivariable logistic regression models were used to assess factors associated with SSI and endometritis. Postpartum outcomes, including length of stay and readmission, were also compared.

RESULTS

We identified 141 cases of SSI and endometritis with an overall postpartum infection rate of 4.0% among all cesarean deliveries. In adjusted analysis, factors associated with both SSI and endometritis were intrapartum delivery, classical or other (non-low-transverse) uterine incision, and blood transfusion. Factors associated with SSI only included inadequate antibiotic prophylaxis, public insurance, hypertensive disorder of pregnancy, and nonchlorhexidine abdominal preparation; factors only associated with endometritis included β-lactam allergy, anticoagulation therapy, and chorioamnionitis. Among cases, 34% of those with SSI and 25% of those with endometritis did not receive adequate antibiotic prophylaxis, compared with 12.9 and 13.5% in control groups, respectively. Failure to receive appropriate antibiotic prophylaxis was associated with an increased risk of SSI (adjusted odds ratio [aOR]: 4.4, 95% confidence interval [CI]: 1.3-15.6) but not endometritis (aOR 0.9, 95% CI 0.4-2.0).

CONCLUSION

Inadequate surgical antibiotic prophylaxis was associated with an increased risk of SSI but not postpartum endometritis, highlighting the different mechanisms of these infections and the importance of prioritizing adequate surgical prophylaxis. Additional potentially modifiable factors which emerged included blood transfusion and chlorhexidine skin preparation.

KEY POINTS

· Inadequate antibiotic prophylaxis is associated with a four-fold risk in surgical site infections.. · The most common cause for failure to achieve adequate surgical prophylaxis was inappropriate timing of antibiotics at or after skin incision.. · Blood transfusions are strongly associated (>10-fold risk) with both SSI and endometritis..

Do maternal albumin levels affect post-operative complications after cesarean delivery?

BACKGROUND

This study explored the correlation between maternal serum albumin levels prior to elective cesarean delivery (CD) and postoperative complications.

METHODS

This retrospective cohort study included women admitted for elective CD at term to our tertiary referral center, during the years 2016-2018. Blood samples were collected during the preoperative admission. Information collected included maternal demographics, pregnancy and postoperative complications. Data between patients with preoperative serum albumin levels < 3.3 g/dL or ≥ 3.3 g/dL were compared.

RESULTS

Among 796 women admitted for an elective CD, 537 met the inclusion criteria. There were 250 (46.6%) women in the low albumin level group (< 3.3 g/dL) and 287 (53.4%) with serum albumin level ≥ 3.3 g/dL. Patients with serum albumin ≥ 3.3 g/dL had increased rates of surgical site infection (SSI) (5.6% vs. 1.6% respectively; p = 0.02), need for antibiotics during the post-partum period (10.8% vs 3.2%, respectively; p = 0.001), surgical intervention (2.1% vs. 0%, respectively; p = 0.03) and higher rate of rehospitalization (5.2% vs. 0.4%, respectively; p = 0.001). Multivariant analysis showed that albumin level ≥ 3.3 g/dL was independently associated with composite postoperative adverse maternal outcome.

CONCLUSIONS

High serum albumin levels among women undergoing CD, might be associated with abnormal postoperative outcomes. Larger prospective studies, with a heterogenous population are needed to validate these observations.

Calculating the appropriate prophylactic dose of cefazolin in women undergoing cesarean delivery

BACKGROUND AND OBJECTIVES

Surgical site infection and other postoperative complications are relatively common in obstetrical procedures, and they are associated with morbidity, prolonged hospital stay, and readmissions. Appropriate levels of antimicrobial agents given directly before skin incision can prevent the establishment of surgical-related infection caused by endogenous microorganisms present on the woman's skin. We aimed to determine serum concentrations of cefazolin given to pregnant women prior to scheduled cesarean delivery and to compare their drug concentrations and pharmacokinetics in 2 weight groups.

STUDY DESIGN

We conducted a prospective cohort analysis of the pharmacokinetics of cefazolin in women undergoing cesarean delivery (August 2017 to September 2018). One or two grams of intravenous cefazolin was administered within 30 min prior to skin incision to women weighing <80 kg and ≥80 kg, respectively. Maternal serum samples were obtained at skin incision and 30 min later. The serum concentration of cefazolin was measured by high-pressure liquid chromatography. Antimicrobial coverage was defined as being appropriate when the cefazolin levels were above the minimal inhibitory concentration. Pharmacokinetic parameters were estimated using a one-compartment model.

RESULTS

A total of 61 women were enrolled, of whom 47 underwent cesarean delivery (study group). The mean time that had elapsed between drug administration to incision was 13 ± 6.9 min (95% confidence interval 10.6-16.2 min). The drug levels after 30 min in women who weighed >80 kg and in women who received 2 g cefazolin, after 30 min from incision differed significantly (87.0 ± 26.0 vs 55.4 ± 16.6 μg/ml, p = .0001).

CONCLUSION

A single 1- or 2-g dose of cefazolin provides serum concentrations above minimal inhibitory concentrations for susceptible pathogens in most women undergoing scheduled cesarean delivery.

Intra-abdominal infection (IAI) following cesarean section: a retrospective study in a tertiary referral hospital in Egypt

BACKGROUND

The incidence of post cesarean intra-abdominal infection (IAI) and the independent risk factors associated with it were retrospectively studied at a tertiary referral hospital in Egypt.

METHODS

The study targeted the period between January 2014 and December 2017 (4 years) at Minia University Hospital for Obstetrics and Gynecology (a tertiary referral hospital), Minia Governorate, Egypt. All cases that developed IAI following cesarean section (CS) during the study period were included (408 cases, which served as the case group); in addition, 1300 cases that underwent CS during the study period and were not complicated by IAI or surgical site Infection (SSI) were randomly chosen from the records (control group). The records of cases and controls were compared and bivariate analysis and multivariate logistic regression were used to identify risk factors for IAI.

RESULTS

During the studied period, there were 35,500 deliveries in the hospital, and 14200 cases (40%) of these were by cesarean section, producing a rate of 40%. The incidence of IAI post CS was 2.87%, and the mortality rate was 1.2% (due to septicemia). The most identifiable risk factors for IAI were chorioamnionitis (AOR 9.54; 95% CI =6.15-16.2; p ≤ 0.001) and premature rupture of membranes (PROM) (AOR 7.54; 95% CI =5.69-10.24; p ≤ 0.001). Risk factors also included: prolonged duration of CS >  1 h (AOR 3.42; 95% CI =2.45-5.23; p = 0.005), no antenatal care (ANC) visits (AOR 3.14; 95% CI =2.14-4.26; p = 0.003), blood loss > 1000 ml (AOR 2.86; 95% CI =2.04-3.92; p = 0.011), emergency CS (AOR 2.24; 95% CI =1.78-3.29; p = 0.016), prolonged labor ≥24 h. (AOR 1.76; 95% CI =1.26-2.27; p = 0.034) and diabetes mellitus (AOR 1.68; 95% CI =1.11-2.39; p = 0.021).

CONCLUSIONS

The incidence of IAI post CS in our hospital was 2.87%. Identification of predictors and risk factors for IAI is an important preventive measure.

Implementation strategies to reduce surgical site infections: A systematic review

BACKGROUND

Surgical site infections (SSIs) portend high patient morbidity and mortality. Although evidence-based clinical interventions can reduce SSIs, they are not reliably delivered in practice, and data are limited on the best approach to improve adherence.

OBJECTIVE

To summarize implementation strategies aimed at improving adherence to evidence-based interventions that reduce SSIs.

DESIGN

Systematic reviewMethods:We searched PubMed, Embase, CINAHL, the Cochrane Library, the WHO Regional databases, AFROLIB, and Africa-Wide for studies published between January 1990 and December 2015. The Effective Practice and Organization Care (EPOC) criteria were used to identify an acceptable-quality study design. We used structured forms to extract data on implementation strategies and grouped them into an implementation model called the "Four Es" framework (ie, engage, educate, execute, and evaluate).

RESULTS

In total, 125 studies met our inclusion criteria, but only 8 studies met the EPOC criteria, which limited our ability to identify best practices. Most studies used multifaceted strategies to improve adherence with evidence-based interventions. Engagement strategies included multidisciplinary work and strong leadership involvement. Education strategies included various approaches to introduce evidence-based practices to clinicians and patients. Execution strategies standardized the interventions into simple tasks to facilitate uptake. Evaluation strategies assessed adherence with evidence-based interventions and patient outcomes, providing feedback of performance to providers.

CONCLUSIONS

Multifaceted implementation strategies represent the most common approach to facilitating the adoption of evidence-based practices. We believe that this summary of implementation strategies complements existing clinical guidelines and may accelerate efforts to reduce SSIs.

Impact of evidence-based interventions on wound complications after cesarean delivery

BACKGROUND

A number of evidence-based interventions have been proposed to reduce post-cesarean delivery wound complications. Examples of such interventions include appropriate timing of preoperative antibiotics, appropriate choice of skin antisepsis, closure of the subcutaneous layer if subcutaneous depth is ≥2 cm, and subcuticular skin closure with suture rather than staples. However, the collective impact of these measures is unclear.

OBJECTIVE

We sought to estimate the impact of a group of evidence-based surgical measures (prophylactic antibiotics administered before skin incision, chlorhexidine-alcohol for skin antisepsis, closure of subcutaneous layer, and subcuticular skin closure with suture) on wound complications after cesarean delivery and to estimate residual risk factors for wound complications.

STUDY DESIGN

We conducted a secondary analysis of data from a randomized controlled trial of chlorhexidine-alcohol vs iodine-alcohol for skin antisepsis at cesarean delivery from 2011-2015. The primary outcome for this analysis was a composite of wound complications that included surgical site infection, cellulitis, seroma, hematoma, and separation within 30 days. Risk of wound complications in women who received all 4 evidence-based measures (prophylactic antibiotics within 60 minutes of cesarean delivery and before skin incision, chlorhexidine-alcohol for skin antisepsis with 3 minutes of drying time before incision, closure of subcutaneous layer if ≥2 cm of depth, and subcuticular skin closure with suture) were compared with those women who did not. We performed logistic regression analysis limited to patients who received all the evidence-based measures to estimate residual risk factors for wound complications and surgical site infection.

RESULTS

Of 1082 patients with follow-up data, 349 (32.3%) received all the evidence-based measures, and 733 (67.7%) did not. The risk of wound complications was significantly lower in patients who received all the evidence-based measures compared with those who did not (20.3% vs 28.1%; adjusted relative risk, 0.75; 95% confidence interval, 0.58-0.95). The impact appeared to be driven largely by a reduction in surgical site infections. Among patients who received all the evidence-based measures, unscheduled cesarean delivery was the only significant risk factor for wound complications (27.5% vs 16.1%; adjusted relative risk, 1.71; 95% confidence interval, 1.12-2.47) and surgical site infection (6.9% vs 1.6%; relative risk, 3.74; 95% confidence interval, 1.18-11.92). Other risk factors, which include obesity, smoking, diabetes mellitus, chorioamnionitis, surgical experience, and skin incision type, were not significant among patients who received all of the 4 evidence-based measures.

CONCLUSION

Implementation of evidence-based measures significantly reduces wound complications, but the residual risk remains high, which suggests the need for additional interventions, especially in patients who undergo unscheduled cesarean deliveries, who are at risk for wound complications even after receiving current evidence-based measures.

Surgical site infection after cesarean delivery: incidence and risk factors at a US academic institution

PURPOSE

To identify the rate of surgical site infection (SSI) after Cesarean delivery (CD) and determine risk factors predictive for infection at a large academic institution.

METHODS

This was a retrospective cohort study in women undergoing CD during 2013. SSIs were defined by Centers for Disease Control (CDC) criteria. Chi square and t-tests were used for bivariate analysis and multivariate logistic regression was used to identify SSI risk factors.

RESULTS

In 2419 patients, the rate of SSI was 5.5% (n = 133) with cellulitis in 4.9% (n = 118), deep incisional infection in 0.6% (n = 15) and intra-abdominal infection in 0.3% (n = 7). On multivariate analysis, SSI was higher among CD for labor arrest (OR 2.4; 95%CI 1.6-3.5; p <.001). Preterm labor (OR 2.8; 95%CI 1.3-6.0; p = .01) and general anesthesia (OR 4.4; 95%CI 2.0-9.8; p = .003) were predictive for SSI. Increasing BMI (OR 1.1; 95%CI 1.05-1.09; p = .02), asthma (OR 1.9; 95%CI 1.1-3.2; p = .02) and smoking (OR 1.9; 95%CI 1.1-3.2; p = .02) were associated with increased SSI.

CONCLUSIONS

Several patient and surgical variables are associated with increased rate of SSI after CD. Identification of risk factors for SSI after CD is important for targeted implementation of quality improvement measures and infection control interventions.

Reliability and validity of using telephone calls for post-discharge surveillance of surgical site infection following caesarean section at a tertiary hospital in Tanzania

Background

Surgical site infection (SSI) is a common post-operative complication causing significant morbidity and mortality. Many SSI occur after discharge from hospital. Post-discharge SSI surveillance in low and middle income countries needs to be improved.

Methodology

We conducted an observational cohort study in Dodoma, Tanzania to examine the sensitivity and specificity of telephone calls to detect SSI after discharge from hospital in comparison to a gold standard of clinician review. Women undergoing caesarean section were enrolled and followed up for 30 days. Women providing a telephone number were interviewed using a structured questionnaire at approximately days 5, 12 and 28 post-surgery. Women were then invited for out-patient review by a clinician blinded to the findings of telephone interview.

Results

A total of 374 women were enrolled and an overall SSI rate of 12% (n = 45) was observed. Three hundred and sixteen (84%) women provided a telephone number, of which 202 had at least one telephone interview followed by a clinical review within 48 h, generating a total of 484 paired observations. From the clinical reviews, 25 SSI were diagnosed, of which telephone interview had correctly identified 18 infections; telephone calls did not incorrectly identify SSI in any patients. The overall sensitivity and specificity of telephone interviews as compared to clinician evaluation was 72 and 100%, respectively.

Conclusion

The use of telephone interview as a diagnostic tool for post-discharge surveillance of SSI had moderate sensitivity and high specificity in Tanzania. Telephone-based detection may be a useful method for SSI surveillance in low-income settings with high penetration of mobile telephones.

Infection Risk in Sterile Operative Procedures

BACKGROUND

The main objective of hospital hygiene and infection prevention is to protect patients from preventable nosocomial infections. It was recently stated that the proper goal should be for zero infection rates in sterile surgical procedures. In this article, we attempt to determine whether this demand is supported by the available literature.

METHODS

We systematically searched the Medline and EMBASE databases for studies published in the last 10 years on the efficacy of infection control measures and carried out a meta-analysis according to the PRISMA tool. We used the following search terms: "aseptic surgery," "intervention," "surgical site infection," "nosocomial infection," "intervention," and "prevention."

RESULTS

2277 articles were retrieved, of which 204 were acquired in full text and analyzed. The quantitative analysis included 7 prospective cohort studies on the reduction of nosocomial infection rates after aseptic surgery. The measures used included training sessions, antibiotic prophylaxis, and operative-site disinfection and cleaning techniques. These interventions succeeded in reducing postoperative wound infections (relative risk (RR] 0.99 [0.98; 1.00]). Subgroup analyses on antibiotic prophylaxis (RR 0.99 [0.98; 1.01]) and noncontrolled trials (RR 0.97 [0.92; 1.02]) revealed small, insignificant effects.

CONCLUSION

A multimodal approach with the participation of specialists from various disciplines can further reduce the rate of postoperative infection. A reduction to zero is not realistic and is not supported by available evidence.