Gilad Gross

Risk Factors for Surgical Site Infection After Low Transverse Cesarean Section

BACKGROUND Independent risk factors for surgical site infection (SSI) after cesarean section have not been well documented, despite the large number of cesarean sections performed and the relatively common occurrence of SSI. OBJECTIVE To determine independent risk factors for SSI after low transverse cesarean section. DESIGN Retrospective case-control study. SETTING Barnes-Jewish Hospital, a 1,250-bed tertiary care hospital. PATIENTS A total of 1,605 women who underwent low transverse cesarean section during the period from July 1999 to June 2001. METHODS Using the International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes for SSI or wound complication and/or data on antibiotic use during the surgical hospitalization or at readmission to the hospital or emergency department, we identified potential cases of SSI in a cohort of patients who underwent a low transverse cesarean section. Cases of SSI were verified by chart review using the definitions from the Centers for Disease Control and Preventions National Nosocomial Infections Surveillance System. Control patients without SSI or endomyometritis were randomly selected from the population of patients who underwent cesarean section. Independent risk factors for SSI were determined by logistic regression. RESULTS SSIs were identified in 81 (5.0%) of 1,605 women who underwent low transverse cesarean section. Independent risk factors for SSI included development of subcutaneous hematoma after the procedure (adjusted odds ratio [aOR], 11.6 [95% confidence interval [CI], 4.1-33.2]), operation performed by the university teaching service (aOR, 2.7 [95% CI, 1.4-5.2]), and a higher body mass index at admission (aOR, 1.1 [95% CI, 1.0-1.1]). Cephalosporin therapy before or after the operation was associated with a significantly lower risk of SSI (aOR, 0.2 [95% CI, 0.1-0.5]). Use of staples for skin closure was associated with a marginally increased risk of SSI. CONCLUSIONS These independent risk factors should be incorporated into approaches for the prevention and surveillance of SSI after surgery.

Effective diminution of amniotic prostaglandin production by selective inhibitors of cyclooxygenase type 2

OBJECTIVE Cyclooxygenase inhibitors are effective tocolytic agents, but significant adverse effects limit their use. We hypothesized that selective inhibitors of the isozyme cyclooxygenase 2 would effectively diminish labor-associated prostaglandin production. STUDY DESIGN We analyzed cyclooxygenase type 1 and 2 expression in amnion, chorion, decidua, and myometrium from laboring or nonlaboring women and tested the efficacy of selective cyclooxygenase 2 inhibition in diminishing prostaglandin production. RESULTS The expression of cyclooxygenase 2 in amnion from women in labor, either preterm or at term, was significantly higher than in amnion before labor. In contrast, cyclooxygenase 1 expression was unchanged by labor. The enhanced expression of amniotic cyclooxygenase 2 was associated with increased prostaglandin E(2) levels in laboring women. Amniotic prostaglandin E(2) production was effectively diminished by the selective cyclooxygenase 2 inhibitors SC-236 and NS-398 but not by the cyclooxygenase 1 inhibitor SC-560. CONCLUSION Selective inhibitors of cyclooxygenase 2 are effective in diminishing prostaglandin production in vitro and may be useful in prevention of preterm deliveries.

Attributable costs of surgical site infection and endometritis after low transverse cesarean delivery.

BACKGROUND Accurate data on costs attributable to hospital-acquired infections are needed to determine their economic impact and the cost-benefit of potential preventive strategies. OBJECTIVE To determine the attributable costs of surgical site infection (SSI) and endometritis (EMM) after cesarean section by means of 2 different methods. DESIGN Retrospective cohort. SETTING Barnes-Jewish Hospital, a 1,250-bed academic tertiary care hospital. PATIENTS There were 1,605 women who underwent low transverse cesarean section from July 1999 through June 2001. METHODS Attributable costs of SSI and EMM were determined by generalized least squares (GLS) and propensity score matched-pairs by means of administrative claims data to define underlying comorbidities and procedures. For the matched-pairs analyses, uninfected control patients were matched to patients with SSI or with EMM on the basis of their propensity to develop infection, and the median difference in costs was calculated. RESULTS The attributable total hospital cost of SSI calculated by GLS was

Evaluation of polymerase chain reaction for group B Streptococcus detection using an improved culture method

3,529 and by propensity score matched-pairs was

Administration of steroids after 34 weeks of gestation enhances fetal lung maturity profiles

2,852. The attributable total hospital cost of EMM calculated by GLS was

Risk factors for endometritis after low transverse cesarean delivery

3,956 and by propensity score matched-pairs was

Comparison of costs of surgical site infection and endometritis after cesarean delivery using claims and medical record data.

3,842. The majority of excess costs were associated with room and board and pharmacy costs. CONCLUSIONS The costs of SSI and EMM were lower than SSI costs reported after more extensive operations. The attributable costs of EMM calculated by the 2 methods were very similar, whereas the costs of SSI calculated by propensity score matched-pairs were lower than the costs calculated by GLS. The difference in costs determined by the 2 methods needs to be considered by investigators who are performing cost analyses of hospital-acquired infections.

Clinical and laboratory trends in fetal lung maturity testing

OBJECTIVE: The administration of antibiotic prophylaxis to laboring women who harbor Group B streptococci (GBS) depends on identification of carriers. We sought to evaluate the diagnostic accuracy of real-time polymerase chain reaction (PCR) for detection of GBS using a more stringent culture method. METHODS: Two swabs were used simultaneously to obtain rectovaginal GBS samples from consenting women. One swab was analyzed using a stringent, validated culture technology, which included direct plating onto selective agar and inoculation of a selective broth. The other swab was used for a commercial real-time PCR assay, which uses amplification to detect the presence of the cfb gene sequence of GBS DNA. We calculated the assay accuracy using sensitivity and specificity. RESULTS: A total of 233 samples were available. Both the culture and PCR methods were positive for 59 and negative for 157 patients. The culture method was positive and PCR was negative in 9 patients. The culture was negative and the PCR positive for 8 patients. The sensitivity of the PCR assay was 86.8% and specificity was 95.2%. The positive predictive value was 88.1% and the negative predictive value was 94.6%. CONCLUSION: Although a rapid PCR assay may be useful to determine GBS status in the urgent intrapartum setting, the false-negative rate of 13.2% for the real-time PCR assay prohibits its use for standard GBS screening in the office. LEVEL OF EVIDENCE: II-1

A barrier retractor to reduce surgical site infections and wound disruptions in obese patients undergoing cesarean delivery: a randomized controlled trial

OBJECTIVE To estimate the effect of antenatal glucocorticoid administration on fetal lung maturity in pregnancies with known fetal lung immaturity between the 34th and 37th weeks of gestation. STUDY DESIGN Pregnancies between 34(0/7) and 36(6/7) weeks undergoing amniocentesis to determine fetal lung maturity were targeted. Women with negative results (TDx-FLM-II <45 mg/g) were randomly assigned to intramuscular glucocorticoid injection or no treatment. A repeat TDx-FLM-II test was obtained 1 week after enrollment. RESULTS Thirty-two women who met inclusion criteria were randomly assigned. Seven women delivered within a week of testing for fetal lung maturity, and were excluded from the analysis. Ten received glucocorticoid and 15 did not. Women assigned to glucocorticoids had a mean increase TDx-FLM-II in 1 week of 28.37 mg/g. Women assigned to no-treatment had an increase of 9.76 mg/g (P < .002). CONCLUSION A single course of intramuscular glucocorticoids after 34 weeks in pregnancies with documented fetal lung immaturity significantly increases TDx- FLM-II.

Tension compared to no tension on a Foley transcervical catheter for cervical ripening: a randomized controlled trial

OBJECTIVE To determine independent risk factors for endometritis after low transverse cesarean delivery. STUDY DESIGN We performed a retrospective case-control study during the period from July 1999 through June 2001 in a large tertiary care academic hospital. Endometritis was defined as fever beginning more than 24 hours or continuing for at least 24 hours after delivery plus fundal tenderness in the absence of other causes for fever. Independent risk factors for endometritis were determined by means of multivariable logistic regression. A fractional polynomial method was used to examine risk of endometritis associated with the continuous variable, duration of rupture of membranes. RESULTS Endometritis was identified in 124 (7.7%) of 1,605 women within 30 days after low transverse cesarean delivery. Independent risk factors for endometritis included age (odds ratio [OR] for each additional year, 0.93 [corrected] [95% confidence interval {CI}, 0.90-0.97]) and anemia or perioperative blood transfusion (OR, 2.18 [CI, 1.30-3.68]). Risk of endometritis was marginally associated with a proxy for low socioeconomic status, lack of private health insurance (OR, 1.72 [CI, 0.99-3.00]); with amniotomy (OR, 1.69 [CI, 0.97-2.95]); and with longer duration of rupture of membranes. CONCLUSION Risk of endometritis was independently associated with younger age and anemia and was marginally associated with lack of private health insurance and amniotomy. The odds of endometritis increased approximately 1.7-fold within 1 hour after rupture of membranes, but increased duration of rupture was only marginally associated with increased risk. Knowledge of these risk factors can guide selective use of prophylactic antibiotics during labor and heighten awareness of the risk in subgroups at highest risk of infection.