Mark D. Hennessy
University of Tennessee Medical Center
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Featured researches published by Mark D. Hennessy.
American Journal of Obstetrics and Gynecology | 1998
Ran Neiger; Mark D. Hennessy; Melan Patel
OBJECTIVES We hypothesize that the success rate of external cephalic version may be increased by performing a repeat attempt with the patient under epidural anesthesia. STUDY DESIGN One hundred eight women with term singleton pregnancies in breech presentation underwent attempted external version. When external version failed, we offered them the option of a later attempt under epidural anesthesia. All fetuses who remained in breech position were delivered by elective cesarean section. RESULTS Fifty (60%) of the 83 attempted external versions performed without anesthesia were successful. Seventeen of the 33 women whose versions were unsuccessful underwent elective cesarean delivery, and 16 elected to undergo repeat version attempts under epidural. Nine (56%) of these 16 procedures were successful, and 7 of these 9 women were delivered vaginally. The overall success rate was 71%, similar to the success rate of versions attempted on 25 women under epidural anesthesia. CONCLUSIONS When an attempted external version fails, a repeat attempt under epidural anesthesia will usually be successful, resulting in a lower cesarean delivery rate.
Obstetrics & Gynecology | 2010
Molly V. Houser; Mark D. Hennessy; Bobby C. Howard
BACKGROUND: In patients with medically refractory seizures, vagal nerve stimulation is becoming an increasingly common adjunctive therapy. Although its safety and efficacy have been proven in the general population, little is known about its use during pregnancy. CASE: A 19-year-old primigravid woman presented during the first trimester for routine prenatal care. She had a past medical history significant for generalized tonic–clonic seizure disorder since childhood. Multiple medical regimens had failed, and a vagal nerve stimulator was implanted approximately 2 months before conception. The patient continued to take phenytoin, with improved seizure control. She had a term spontaneous delivery complicated by mild preeclampsia. CONCLUSION: Adjunctive treatment of medically refractory seizures with a vagal nerve stimulator is a viable option during pregnancy.
American Journal of Obstetrics and Gynecology | 2014
Cheryl N. Onwuchuruba; Craig V. Towers; Bobby C. Howard; Mark D. Hennessy; Lynlee Wolfe; Marjorie S. Brown
OBJECTIVE The objective of the study was to analyze a large number of patients receiving vancomycin chemoprophylaxis and evaluate the maternal and neonatal cord blood levels at the time of delivery. STUDY DESIGN Every mother who entered labor with a positive group B streptococcal culture and a high-risk penicillin allergy with resistance to clindamycin or unknown sensitivity was consented to participate in the study. In the initial phase of the study, patients received the standard intravenous dose of 1 g every 12 hours. Based on the results, this was changed to a dosing of 15 mg/kg every 12 hours in the second phase and then further modified to 20 mg/kg every 8 hours in the third phase. Maternal and cord blood vancomycin levels were obtained at delivery and evaluated. RESULTS A total of 55 patients consented to participate in the study, with 31 in phase I, 12 in phase II, and 12 in phase III. For the standard-dosing phase I group, only 32% of maternal and 9% of cord blood samples were therapeutic at delivery. For phase II, 50% of maternal and 33% of cord blood values were therapeutic; however, in phase III, 83% of mothers and neonates had therapeutic levels at the time of delivery. CONCLUSION With standard dosing, only 9% of neonates have therapeutic vancomycin levels at delivery. By using a regimen of 20 mg/kg intravenous every 8 hours (maximum individual dose 2 g), the newborn therapeutic level increases above 80%. The pharmacological pattern shows that transplacental passage occurs with fetal levels equaling maternal levels, but transplacental transport is somewhat slow in both directions.
Obstetrics & Gynecology | 2016
Noelle Fernandez; Craig V. Towers; Lynlee Wolfe; Mark D. Hennessy; Beth Weitz; Stephanie Porter
OBJECTIVE: To evaluate possible modes of hepatitis C virus (HCV) acquisition in pregnant women found to be HCV-infected in the prenatal period and to assess transmission risk factors. METHODS: This was a prospective cohort study conducted from March 2014 through June 2015 involving the distribution of an anonymous survey to HCV-infected pregnant women that assessed for numerous modes of potential HCV transmission involving, intravenous drug use, blood transfusion, organ transplant, sexual contact, tattoos, and snorting drugs with a straw. Participants were drawn from our institutional obstetric high-risk clinic. Statistical analysis involved simple percentages and &khgr;2 comparisons where appropriate; P<.05 was considered significant. To test biologic plausibility, snorting utensils confiscated by law enforcement authorities from patients not in this study were tested for the presence of human blood. RESULTS: A total of 189 HCV-infected pregnant patients completed the survey, and no approached patients declined. Of these, 136 (72%, 95% confidence interval [CI] 65–78%) admitted to intravenous drug use, of whom 89 (65%, 95% CI 57–73%) reported sharing needles. Of the 178 (94%, 95% CI 90–97%) who admitted snorting drugs, 164 (92%, 95% CI 87–96%) reported sharing straws. The difference between the proportion reporting sharing of snorting utensils compared with the proportion sharing intravenous drug use utensils was significant (P<.001). Twenty-nine patients (15%, 95% CI 11–21%) reported snorting drugs and sharing straws but denied any other risk factor except sexual contact. Of the 54 straws confiscated by law enforcement authorities, 13 (24%, 95% CI 13–38%) tested positive for the presence of human blood. CONCLUSION: Sharing snorting utensils (straws) in noninjection drug use may be an additional risk factor for HCV and other virus transmission.
American Journal of Obstetrics and Gynecology | 2015
Megan Rooney Thompson; Craig V. Towers; Bobby C. Howard; Mark D. Hennessy; Lynlee Wolfe; Callie Heitzman
OBJECTIVE Prostaglandin E₁ (PGE₁) is commonly used in obstetric practice for labor induction and cervical ripening and in treating postpartum hemorrhage; however, its use in pregnant asthmatic patients has not been studied to date. The package insert states there is an unknown causal side effect for dyspnea and bronchospasm. Other pharmacological publications have stated that bronchoconstriction may occur with the use of PGE₁. The study objective was to examine peripartum pregnant asthmatic patients who received prostaglandin E₁. STUDY DESIGN Every patient who was administered PGE₁ from January 2010 through December 2013 was prospectively recorded. The charts were retrospectively reviewed. Peripartum patients with asthma were identified and further analyzed for any evidence of an asthma exacerbation following administration of the drug. RESULTS A total of 234 of 2629 patients (8.9%) who received PGE₁ were identified as having asthma. None of the patients had any evidence of an asthma exacerbation (0 of 234; 95% confidence interval, 0-0.017). Of the 234 patients, 104 (44%) had active asthma and were receiving daily medication, and the remaining 130 patients had a medical history of asthma for which they used an inhaler on an as-needed basis. A total of 98 patients (42%) received greater than 400 μg of total dose. A post hoc statistical assessment was performed, and the study was sufficiently powered to detect any clinically meaningful increase in asthma exacerbation with PGE₁ usage, if such a risk existed. CONCLUSION Based on the 95% confidence interval of these data, the maximum risk for an asthma exacerbation following the use of prostaglandin E₁ is less than 2%. Although all medications administered to asthmatic patients in the peripartum period should be carefully selected, this information supports the use of prostaglandin E₁ in obstetric patients with asthma, if clinically indicated.
Journal of Maternal-fetal & Neonatal Medicine | 2015
Meredith Fields; Craig V. Towers; Bobby C. Howard; Mark D. Hennessy; Lynlee Wolfe; Beth Weitz; Stephanie Porter
Abstract Objective: To determine whether meconium-contaminated amniotic fluid falsely elevates the lamellar body count in fetal lung maturity testing. Methods: Thirty mothers undergoing amniocentesis for fetal lung maturity testing were prospectively consented. A 2 mL portion of the patient’s sample was mixed with a 10% meconium solution and the meconium-stained sample was then run in tandem with the patient’s sample used in clinical management. Pure meconium samples without amniotic fluid were also run through the cell counter for analysis. Results: Following meconium contamination, the lamellar body count value increased in 67% of the cases, decreased in 23% and remained the same in 10%. There were 13 test results that had “immature” values in the uncontaminated patient management sample group and nine of these (69%) became elevated to a “mature” level (a false elevation) following the addition of meconium. All of the 10 pure liquid meconium samples devoid of amniotic fluid processed by the cell counter identified and quantified some particle the size of platelets. Conclusions: The lamellar body count test result is not reliable in meconium-stained amniotic fluid specimens. There is some unknown particle found in meconium that is the size of platelets/lamellar bodies that can falsely elevate the test result. Currently, the only reliable fetal lung maturity test in meconium-stained amniotic fluid is the presence of phosphatidylglycerol.
American Journal of Obstetrics and Gynecology | 2016
Jennifer Bell; Craig V. Towers; Mark D. Hennessy; Callie Heitzman; Barbara Smith; Katie Chattin
American Journal of Obstetrics and Gynecology | 2016
Craig V. Towers; Mark D. Hennessy
American Journal of Obstetrics and Gynecology | 2016
Craig V. Towers; Mark D. Hennessy
Journal of Reproductive Medicine | 2015
Kevin Visconti; Craig V. Towers; Mark D. Hennessy; Bobby C. Howard; Stephanie Porter; Beth Weitz