Does current cefazolin dosing achieve adequate tissue and blood concentrations in obese women undergoing cesarean section?

BACKGROUND: Prophylactic administration of antibiotics preceding cesarean delivery is the most effective measure taken for preventing postpartum infection. While obese women are at greater risk for infection than non-obese women, evidence-based recommendations for modifying dosing in these women are limited. OBJECTIVES: The purpose of this study was to determine whether obese women undergoing cesarean delivery similarly reach adequate cefazolin concentrations within tissue and blood when weighing <120kg and dosed 2g versus weighing ≥120kg and dosed 3g. STUDY DESIGN: We prospectively studied women ≥18 years old with body mass index ≥30kg/m2 who underwent scheduled cesarean delivery with singleton pregnancy from August 2014 through March 2016. Women were dosed with 2g and 3g of cefazolin for body weights <120kg and ≥120kg, respectively. Samples of subcutaneous adipose tissue (following skin incision and before skin closure), myometrial tissue, fetal cord blood, and maternal blood were collected to assess whether cefazolin concentrations were adequate, i.e., at/above the minimum inhibitory concentration (MIC). Concentrations, based on inhibition zones for Streptococcus sanguinis, were calculated per gram of solid tissue and milliliter of blood. For all sample types, log-transformed concentrations were compared between dosage groups. Using a range of published MICs (1-8µg/mL or µg/g), odds ratios, describing differential odds of falling below the MIC between dosage groups, were also computed. RESULTS: Women who received 2g (n=65) versus 3g (n=19) of cefazolin did not significantly differ by maternal or gestational age, race/ethnicity, pre-operative hemoglobin, estimated blood loss, fluid administration, duration of surgery, or timing of sample collections relative to cefazolin administration (Ps>0.05). Dosage groups also did not differ in cefazolin concentration (median [interquartile range]) within adipose tissue following skin incision (5.30µg/g [3.00-9.60] vs. 6.35µg/g [3.90-8.40]; P=0.551), adipose tissue before skin closure (4.45µg/g [2.78-7.25] vs. 6.90µg/g [2.60-10.6]; P=0.342), myometrial tissue (13.1µg/g [8.60-19.6] vs. 15.7µg/g [10.8-21.7]; P=0.116), or maternal blood (41.6µg/mL [26.3-57.0] vs. 45.3µg/mL [36.7-68.3]; P=0.143). However, cord blood concentrations differed significantly (19.5µg/mL [13.7-28.5] vs. 27.9µg/mL [15.8-39.4]; P=0.032), and, in 3 of 5 sample types, group concentrations differed at the dosing cut-point of 120kg (Ps<0.02). Within the range of MICs considered, differences in the odds of concentration inadequacy were not detected between dosage groups for any sample type. Across all patients, inadequate concentrations in one or more solid tissue types were observed in 1.19%, 17.9%, 59.5%, and 86.9% of patients, given the MICs of 1µg/g, 2µg/g, 4µg/g and 8µg/g, respectively. In adipose tissues, specifically, and both dosage groups, mean concentrations were significantly lower than the MIC of 8µg/g (Ps<0.03). Concentrations in one or both blood sample types were inadequate for only 8.33% of patients, given the 8-µg/mL MIC. CONCLUSIONS: Adequate cefazolin concentrations were achieved in blood for the majority of our patients. However, concentration adequacy was not achieved in solid tissue for a nearly equally large proportion of patients. Larger scale studies for determining modified protocols for dosing and applying MICs are warranted.

Foley catheter placement for induction of labor with or without stylette: a randomized clinical trial.

BACKGROUND: Foley catheters are used for cervical ripening during induction of labor. Previous studies suggest that use of a stylette (a thin, rigid wire) to guide catheter insertion decreases insertion failure. However, stylette effects on insertion outcomes have been sparsely studied. OBJECTIVE: The purpose of this study was to compare catheter insertion times, patient-assessed pain levels, and insertion failure rates between women who received a digitally placed Foley catheter for cervical ripening with the aid of a stylette and women who received the catheter without a stylette. STUDY DESIGN: We conducted a randomized clinical trial of women aged ≥ 18 years who presented for induction of labor. Inclusion criteria were singletons with intact membranes and cephalic presentation. Women received a computer-generated random assignment of a Foley catheter insertion with a stylette (treatment group, n = 62) or without a stylette (control group, n = 61). For all women, a standard insertion technique protocol was used. Three primary outcomes were of interest, including the following: (1) insertion time (total minutes to successful catheter placement), (2) patient-assessed pain level (0-10), and (3) failure rate of the randomly assigned insertion method. Treatment control differences were first examined using the Pearson's test of independence and the Student t test. Per outcome, we also constructed 4 regression models, each including the random effect of physician and fixed effects of stylette use with patient nulliparity, a history of vaginal delivery, cervical dilation at presentation, or postgraduate year of the performing resident physician. RESULTS: Women who received the Foley catheter with the stylette vs without the stylette did not differ by age, race/ethnicity, body mass index, or any of several other characteristics. Regression models revealed that insertion time, patient pain, and insertion failure were unrelated to stylette use, nulliparity, and history of vaginal delivery. However, overall insertion time and failure were significantly influenced by cervical dilation, with insertion time decreasing by 21% (95% confidence interval [CI], 5-34%) and odds of failure decreasing by 71% (odds ratio, 0.29; 95% CI, 0.10-0.86) per 1 cm dilation. Resident postgraduate year also significantly influenced insertion time, with greater time required of physicians with less experience. Mean insertion time was 51% (95% CI, 23-69%) shorter for fourth-year than second-year residents. Statistically nonsignificant but prominent patterns in outcomes were also observed, suggesting stylette use may lengthen the overall insertion procedure but minimize variability in pain levels and decrease insertion failure. CONCLUSIONS: The randomized trial suggests that, even after accounting for nulliparity, history of vaginal delivery, cervical dilation, and physician experience, Foley catheter insertions with and without a stylette are equivalent in insertion times, patient pain levels, and failure of catheter placement.

Serum 25-hydroxyvitamin D, calcium, and calcium-regulating hormones in preeclamptics and controls during first day postpartum.

The evidence for a link between vitamin D and preeclampsia is conflicting. There is a paucity of studies reporting simultaneous 25-hydroxyvitamin D (inactive form) and 1,25-dihydroxyvitamin D (biologically active form). We investigated if levels of serum 25-hydroxyvitamin D, calcium-regulating hormones (1,25-dihydroxyvitamin D, parathyroid hormone), and calcium differ significantly between preeclamptics and controls. On postpartum day one, 98 subjects (44 with preeclampsia, 54 controls) were recruited among women admitted to the postdelivery unit, and their serum 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, parathyroid hormone, serum calcium, and serum albumin levels were prospectively measured. The majority of participants (70%) had serum 25-hydroxyvitamin D level<20 ng/mL; 53% had <15 ng/mL. Mean serum 25-hydroxyvitamin D level was similar between cases and controls (p=0.50). Mean total serum calcium adjusted for albumin and magnesium was similar between cases and controls (p=0.78). Mean serum 1,25-dihydroxyvitamin D and parathyroid hormone levels were normal, and there were no differences between cases and controls. The only significant differences found between preeclamptic cases and controls were mean body mass index, parity, and season of blood draw. Vitamin D levels did not differ among preeclamptic cases and controls.

Umbilical cord plasma and salivary insulin and leptin concentrations in AGA neonates: a preliminary report.

UNLABELLED: Background and objective: Insulin and leptin hormones are important regulators of food intake and energy balance. There is limited information about insulin and leptin hormones in neonates. This preliminary study aimed to investigate the concentrations of insulin and leptin in umbilical cord plasma and neonate's saliva and their relationships. METHODS: Umbilical cord plasma and salivary samples were obtained from 13 healthy, appropriate for gestational age (AGA) neonates. Insulin and leptin concentrations in umbilical cord plasma and saliva were measured using the MILLIPLEX MAP® Human Metabolic Hormone Magnetic Bead Panel. RESULTS: Insulin concentrations in umbilical cord plasma correlates positively and significantly with leptin concentrations in umbilical cord plasma (r = 0.55, p = 0.04). CONCLUSIONS: More research is needed to explore the relationships between insulin and leptin hormones in neonate's saliva.

American college of obstetricians and gynecologists practice bulletins: ascertaining their citation, influence, and utilization.

OBJECTIVE: To ascertain the influence and utilization of the American College Obstetricians and Gynecologists practice bulletins (PBs) by measuring their citations in three different search tools. STUDY DESIGN: PBs in obstetrics (OB-PBs) and gynecology (GYN-PBs) published from September 1998 to December 2009 were identified. PubMed, Ovid MEDLINE, and Web of Science were utilized to determine how often PBs were cited. The citations were quantified by three parameters, most citations, highest citation rate, and highest impact factor. RESULTS: The OB-PB with the most citations (125) was PB no. 33 (Diagnosis and Management of Preeclampsia and Eclampsia), highest citation rate (44) was PB no. 101 (Ultrasonography in Pregnancy), highest OBGYN impact factor (4.39) was PB no. 71 (Episiotomy), and highest non-OBGYN impact factor (53.49) was PB no. 38 (Perinatal Care at Threshold of Viability). The GYN-PB with the highest citation rate (103) was PB no. 109 (Cervical Cytology Screening), highest OBGYN impact factor (3.85) was PB no. 103 (Hereditary Breast and Ovarian Cancer Syndrome), and highest non-OBGYN impact factor (20.89) was PB no. 35 (Cervical Carcinoma). CONCLUSIONS: No one PB had the most citations, highest citation rate, and highest impact factor.

Racial and ethnic disparities in infant mortality in the United States: the role of gestational age.

OBJECTIVE: We assessed the association among gestational age (GA) at birth, timing of death, and risk status of the pregnancy and racial/ethnic disparities in infant mortality rate in the United States. STUDY DESIGN: We utilized U.S. 2000 to 2004 birth cohort-linked birth and infant death data restricted to nonanomalous singleton live births. Multivariable log-binomial regression models were fit to evaluate racial/ethnic disparities in infant mortality while adjusting for potential confounders. RESULTS: Compared with whites, blacks had a higher adjusted infant mortality rate (IMR) (risk ratio [RR] 1.96, 95% confidence interval [CI] 1.91, 2.01), and Hispanics had a lower adjusted IMR (RR 0.79, 95% CI 0.76, 0.82). When categorized by GA, at 24 to 31 weeks, the adjusted early neonatal mortality (ENM) is significantly lower for black than whites, similar at 32 to 36 weeks, and at 37 weeks or more, blacks have significantly higher ENM. CONCLUSIONS: The racial/ethnic disparities in infant mortality in the United States persist and vary across GA. These disparities may largely be driven by the excess post-neonatal deaths among blacks.

Skin closure of pfannenstiel incision with dermabond, staples, or suture during cesarean delivery: experience of a single attending.

OBJECTIVE: We aimed to compare the rates of wound separation (WS) and surgical site infection (SSI) after cesarean delivery (CD) by a single surgeon. Pfannenstiel skin incision (PSI) was closed with Dermabond, staples, or suture. STUDY DESIGN: Retrospectively all women having CD via PSI were identified. WS and SSI rates with Dermabond were compared with other two techniques. RESULTS: Of 239 CDs performed, 88% (n = 211) were available for postpartum evaluation. The PSI was closed with Dermabond in 85 (40%), staples in 76 (36%), and suture in 50 (24%). Overall WS rate was 7%; with Dermabond, it was 5% versus 13% with staple (p = 0.090) and 2% with suture (p = 0.651). Post hoc calculation suggests a randomization of 4325 women is needed to determine if Dermabond has one-third less wound complication than suture. CONCLUSION: For the PSI closure, Dermabond may be a useful alternative skin closure device, though a randomized trial is warranted.

Successful utilization of a novel aspiration thrombectomy catheter (Pronto) for the treatment of patients with stent thrombosis.

Stent thrombosis is a rare but catastrophic complication of percutaneous coronary intervention (PCI). Thrombolytic therapy is ineffective for the treatment of patients with stent thrombosis, while primary PCI in such patients is limited by a high thrombus burden in the culprit vessel often leading to distal embolization and extensive tissue infarction. We present three patients with stent thrombosis successfully treated with the adjunctive use of a novel and new aspiration thrombectomy device (Pronto).

Clinical utility of aortic pulses and pressures calculated from applanated radial-artery pulses.

Brachial artery cuff blood pressures are but approximations of central aortic pressures. The actual pressures against which the left ventricle must pump would be useful clinical information if obtained noninvasively. Our aim was to determine the clinical utility of aortic pulses and pressures calculated from noninvasively obtained radial-artery pulses. Radial-arterial pulses were recorded by applanation and calibrated with arm/cuff oscillometric pressures. Aortic pulses and pressures were calculated from the radial pulses by Fourier analysis and transfer functions. These calculated aortic pulses were compared with directly recorded aortic pulses by a transducer-tip catheter in a series of 50 patients undergoing cardiac catheterization. The correlation coefficient (r) of the measured versus the calculated aortic systolic blood pressure was +0.89, but the scatter was large (standard deviation of the differences=+/-11.3 mm Hg). The pulse pressure correlations were less good (r=+0.79) and also had a large scatter (+/-13.6 mm Hg). The average calculated pulse pressure was 11.5 mm Hg lower than the measured value because the cuff diastolic blood pressures, used to calibrate the radial pulses, were systematically higher than those in the aorta (8.9 mm Hg). Multivariable analysis incorporating height, age, heart rate, and ejection fraction as additional, independent variables eliminated mean differences between the new "predicted" and measured pressures, significantly improved correlation coefficients, and reduced the scatter. However, the improvements were small. The inaccuracy of the oscillometric cuff method for measuring arm blood pressure appears to be the limiting factor in the prediction of clinically useful, noninvasive aortic pressures.