Obstetric hemorrhage survey: Attitudes and practices of maternal-fetal medicine fellows.

OBJECTIVE: To evaluate experiences related to obstetric hemorrhage and suspected abnormal placentation among first year maternal-fetal medicine fellows. STUDY DESIGN: A cross-sectional anonymous survey was administered at the Society for Maternal-Fetal Medicine fellow retreat in March 2013. Fellows were asked about management strategies that reflected both their individual and institutional practices. RESULTS: There was a 56% response rate (55/98). In cases of postpartum hemorrhage due to uterine atony, there was variable use of the uterine tamponade device. The median incremental time for balloon deflation was every 5 hours (IQR = 2-12). Compared to the east coast, fellows from the west coast performed more hysterectomies (mean±SD; 2.9±2.4 vs. 1.2±1.2, p = 0.004). During a peripartum hysterectomy, 29% of fellows used a handheld cautery device such as Ligasure® or Gyrus®. Fifty-six percent responded that their institution never recommend planned delayed hysterectomies for abnormal placental implantation. CONCLUSION: There is wide variation in practice among first year maternal-fetal medicine fellows in management of peripartum hysterectomy and postpartum hemorrhage.

Lung area--volume models in relation to the recruitment--derecruitment of individual lung units.

The objective of this study was to reconsider some of the previous experimental results in terms of simple geometric models in order to determine if any of the apparent conflicts could be explained within a more unified concept. These models allow individual lung units and the entire lung to expand differently with regard to their area-volume relationship. The effect of a recruitment-derecruitment process as the lung inflates-deflates is also considered. Examples are used to illustrate how some of the apparent conflicts found in the literature may arise from whether or not recruitment and derecruitment take place during lung expansion and contraction.

Wound infection in gynecologic surgery.

OBJECTIVE: We sought to determine the wound infection rate among patients undergoing elective gynecologic surgery at a single tertiary care center and to determine the predictive value of various factors that contribute to infection. We further investigated the adequacy of hospital records in documenting infection rates as well as the timing of presentation of wound infections. METHODS: The records of 115 patients undergoing elective gynecologic surgery at our institution were reviewed. Patients were further subdivided based on route of surgery. We analyzed the importance of antibiotic prophylaxis, route of surgery, smoking, diabetes, and body mass index (BMI). RESULTS: The overall wound infection rate was 12.17% with no significant difference in the subgroups by route of surgery. Overall, antibiotic prophylaxis significantly decreased infection rates (P = 0.0118), but the route of surgery, BMI, smoking, and diabetes were not significant predictors of infection. Only one case of infection was detected during the initial hospital stay (6.1%). Fifty percent of the patients with infection required readmission, and of these 35.7% required an additional surgical procedure. The average length of hospital stay was 2.4 days longer in patients with infection. CONCLUSIONS: Antibiotic prophylaxis has a role in the management of patients undergoing abdominal gynecologic surgery. In today's environment of cost containment, an increased hospital stay and the added likelihood of additional surgical intervention associated with wound infection are important targets for prevention. Most patients with wound infection were diagnosed after discharge from the hospital. In our population, among whom transportation problems and remote residence are prevalent, strategies for infection surveillance should be integral to discharge planning.

Detection of pericentric inversion of X chromosome in a male fetus.

Amniocentesis on a 32-year-old woman at risk for trisomy 21 by maternal serum triple screen showed a 46,Y,inv(X) (p22.1q24) karyotype in all cells analyzed. A blood sample was obtained from the mother for cytogenetic evaluation. Since she had the same inversion, DNA replication studies were performed to determine if the X inactivation pattern was random or not, since skewed inactivation of the inverted X might suggest that the breakpoints disrupted functional genes. DNA replication studies demonstrated that 68% of mother's cells with the inverted X were active, suggesting random X inactivation. The random X inactivation pattern suggested that the inversion is probably balanced and should not affect the fetus. A normal male was delivered at 40 weeks gestation.

On the relevance of locus equations for production and perception of stop consonants.

We examined the possible relevance of locus equations to human production and perception of stop consonants. The orderly output constraint (OOC) of Sussman, Fruchter, and Cable (1995) claims that humans have evolved to produce speech such that F2 at consonant release and F2 at vowel midpoint are linearly related for consonants so that developing perceptual systems can form representations in an F2ons-by-F2vowel space. The theory claims that this relationship described by locus equations can distinguish consonants, and that the linearity of locus equations is captured in neural representations and is thus perceptually relevant. We investigated these claims by testing how closely locus equations reflect the production and perception of stop consonants. In Experiment 1, we induced speakers to change their locus equation slope and intercept parameters systematically, but found that consonants remained distinctive in slope-by-intercept space. In Experiment 2, we presented stop-consonant syllables with their bursts removed to listeners, and compared their classification error matrices with the predictions of a model using locus equation prototypes and with those of an exemplar-based model that uses F2ons and F2vowel, but not locus equations. Both models failed to account for a large proportion of the variance in listeners' responses; the locus equation model was no better in its predictions than the exemplar model. These findings are discussed in the context of the OOC.

Peak expiratory flow rate in normal pregnancy.

OBJECTIVE: To determine whether peak expiratory flow rate changes with pregnancy and advancing gestation. METHODS: We measured the peak expiratory flow rate in 57 women during each trimester of pregnancy and postpartum. During four visits, all subjects exhaled forcefully three times into a peak flow meter. For each visit, the best of three attempts defined their peak expiratory flow rate. Using accepted standard nomograms, we normalized peak expiratory flow rate with respect to height and age. Using analysis of variance, we compared the mean normalized peak expiratory flow rates in each of the trimesters and postpartum. RESULTS: The subjects' peak expiratory flow rates did not change significantly during the three trimesters and postpartum (P = .317). The mean peak expiratory flow rates for the three trimesters and postpartum were 434 +/- 18, 452 +/- 16, 444 +/- 15, and 450 +/- 16 (values in liters per minute +/- 95% confidence intervals [CIs]). The mean normalized peak expiratory flow rates for the three trimesters and postpartum were 0.92 +/- 0.036, 0.95 +/- 0.032, 0.94 +/- 0.030, and 0.95 +/- 0.031 (values +/- 95% CI). CONCLUSIONS: This study demonstrates that peak expiratory flow rate does not change with pregnancy and advancing gestation. Therefore, testing peak expiratory flow rate in pregnancy is valid, and physicians can use peak expiratory flow rate accurately and reliably in the management of pregnant women with asthma.

Pharmacokinetics and pharmacodynamics of subcutaneous heparin during the early third trimester of pregnancy.

OBJECTIVE: Our purpose was to study the pharmacokinetics and pharmacodynamics of heparin administered subcutaneously during the early third trimester of pregnancy. STUDY DESIGN: We gave subcutaneous heparin (143 units/kg) to six pregnant women (mean gestational age 27.1 +/- 1.2 weeks) and to six women who were not pregnant, who served as controls. We serially measured plasma heparin concentrations and activated partial thromboplastin times over 10 hours and compared the time courses of these two measures in the two groups. We calculated the mean peak plasma heparin concentration, time to peak plasma heparin concentration, peak activated partial thromboplastin time, and time to peak activated partial thromboplastin time and compared these variables in the two groups. RESULTS: Plasma heparin concentrations changed significantly over time in both pregnant and nonpregnant subjects. However, the peak plasma heparin concentration in pregnant subjects was significantly lower than in controls (0.11 +/- 0.017 units/ml vs 0.23 +/- 0.036 units/ml) and the time to peak plasma heparin concentration was significantly shorter in the pregnant patients compared with the nonpregnant controls (113 +/- 20 minutes vs 222 +/- 20 minutes). The peak activated partial thromboplastin time (30.3 +/- 1.7 seconds) was significantly lower and time to peak activated partial thromboplastin time (137 +/- 31 minutes) significantly shorter in the pregnant women compared with nonpregnant controls (50 +/- 4.0 seconds; 230 +/- 26 minutes). CONCLUSIONS: Subcutaneous administration of heparin to pregnant patients results in lower plasma heparin concentrations and clinically insignificant prolongation of the activated partial thromboplastin time compared with equivalent doses administered to nonpregnant women. These findings have important implications for the dosing and monitoring of subcutaneous heparin in pregnant women.

DNA analysis of multiple synchronous renal cell carcinomas.

The authors used retrospective quantitative DNA analysis to study interrelationships between multiple synchronous renal cell carcinomas in seven patients. DNA content was determined by image analysis on Feulgen-stained nuclear smears prepared from multiple paraffin blocks from each tumor. Tumors were unilateral in four cases and bilateral in three. Ten tumors had homogeneous, and four heterogeneous DNA stemlines. Intertumoral heterogeneity in four cases suggested multifocal origin. Identical DNA aneuploid indices in bilateral tumors in one case suggested metastasis from a solitary origin. Abnormal DNA content and heterogeneous populations began to appear in the size range 2.0 to 5.0 cm. All tumors over 5.0 cm contained nondiploid populations. Although the interrelationships between these multiple synchronous neoplasms are not entirely clear, the DNA analysis suggests that the occurrence of nondiploid stemlines and heterogeneous DNA content may parallel both tumor growth and more aggressive behavior.

Comparison of lung sounds and gas trapping in the study of airway mechanics.

We have previously shown that gas is trapped in isolated animal lungs and have proposed that this gas-trapping process is related to meniscus formation in the small airways of the lung. The purpose of this investigation was to compare how the lung sound-generation process and the gas-trapping process are related to airway mechanics and each other. Rats were anesthetized, the heart and lungs were removed en bloc and placed in a liquid-filled plethysmograph. Lung sounds were recorded by using a microphone acoustically coupled to the tracheal cannula. The results show that discontinuous lung sounds in the form of crackles occur during lung inflation at the same time gas trapping takes place.