Biomedical subjects

John C Morrison

Publications and source records attributed to John C Morrison.

At least 37 records · Page 2Linked to original sources

PubMed2005

The length of the third stage of labor and the risk of postpartum hemorrhage.

OBJECTIVE: To estimate whether the length of the third stage of labor is correlated with postpartum hemorrhage. METHODS: In this prospective observational study women delivering vaginally in a tertiary obstetric hospital were assessed for postpartum hemorrhage. All women were actively managed with the administration of oxytocin upon delivery of the anterior shoulder. Blood loss was measured at each delivery in collecting devices, and drapes and sheets were weighed to calculate the blood loss at each vaginal delivery. Postpartum hemorrhage was defined as more than 1,000 mL blood loss or hemodynamic instability related to blood loss requiring a blood transfusion. RESULTS: During a 24-month period there were 6,588 vaginal deliveries in a single tertiary obstetric hospital, and postpartum hemorrhage occurred in 335 of these (5.1%). The median length of the third stage of labor was similar in women having and those not having a postpartum hemorrhage. The risk of postpartum hemorrhage was significant at 10 minutes, odds ratio (OR) 2.1, 95% confidence interval (CI), 1.6-2.6; at 20 minutes, OR 4.3, 95% CI 3.3-5.5; and at 30 minutes OR 6.2, 95% CI 4.6-8.2. The best predictor for postpartum hemorrhage using receiver operating characteristic curves was 18 minutes. CONCLUSION: A third stage of labor longer than 18 minutes is associated with a significant risk of postpartum hemorrhage. After 30 minutes the odds of having postpartum hemorrhage are 6 times higher than before 30 minutes. LEVEL OF EVIDENCE: III.

Adult↗

PubMed2005

Elevated intraocular pressure and optic nerve injury models in the rat.

Models of experimentally elevated intraocular pressure in rats provide valuable opportunities to discover and study mechanisms of pressure-induced optic nerve damage. The structure and vasculature of the rat optic nerve head have several anatomic similarities and differences from the primate that allow useful comparisons and insights into human glaucoma. Specifically, the ultrastructural relationship between astrocytes, retinal ganglion cell axons and the connective tissues of the optic nerve head appear quite similar to the primate, and have a high potential for revealing cellular mechanisms of axonal injury. Three widely used models of creating elevated IOP in rats exist. However, they are not all equivalent and appear to differ in the relationship they exhibit between the level of pressure and extent of optic nerve damage. This indicates that these models may differ in the mechanisms by which they produce elevated eye pressure. All of these models are amenable to a variety of methods for evaluating damage. These include objective and subjective histologic assessment of the optic nerve, counting cells in the retinal ganglion cell layer of the retina and the use of retinal whole mounts to count retinal ganglion cells that have been back-labeled with dye applied to the superior colliculus. In the decade since their introduction, these versatile models have provided important insights into mechanisms of pressure-induced optic nerve damage using sensitive molecular biology techniques. They have also allowed the evaluation of several potential strategies for neuroprotection in glaucoma, ranging from currently available drugs to gene transfer studies.

Animals↗

PubMed2005

Depression screening in the pregnant soldier wellness program.

OBJECTIVES: The purpose of this study was to determine the prevalence of depression among active-duty low-risk pregnant women using the Edinburgh Postnatal Depression Scale. Rates for depression have been reported to be as high as 13% during pregnancy and 12 to 22% postpartum, with postpartum suicidal ideation at nearly 7%. METHODS: From April 2002 through March 2003, 82 women receiving prenatal care at Madigan Army Medical Center completed screening questionnaires during pregnancy and/or postpartum visits. RESULTS: A total of 97 questionnaires were administered (71 antepartum and 26 postpartum). During pregnancy, 24% of individuals screened scored positive. During the postpartum, 19% scored positive. A total of 15 women were screened twice during the study period. One woman was screened twice during pregnancy and the remaining 14 were screened once antepartum and once postpartum. Suicidal ideation was present in 11% of those screened during pregnancy and in 15% postpartum. CONCLUSIONS: Active-duty women appear to have a higher rate of depression and suicidal ideation compared with rates in nonmilitary populations; perhaps such screening should become a standard practice.

Depression↗

PubMed2005

Postpartum hemorrhage after vaginal birth: an analysis of risk factors.

OBJECTIVE: To determine, in a single tertiary obstetric hospital, the incidence of and risk factors for postpartum hemorrhage (PPH) after a vaginal birth. METHODS: PPH was defined as measured blood loss greater than 1,000 mL and/or need for a transfusion. RESULTS: Over a 4-year period, 13,868 of 19,476 women delivered vaginally, with a PPH rate of 5.15%. Identified risk factors for PPH were Asian race, maternal blood disorders, prior PPH, history of retained placenta, multiple pregnancy, antepartum hemorrhage, genital tract lacerations, macrosomia (>4 kg), and induction of labor, as well as chorioamnionitis, intrapartum hemorrhage, still birth, compound fetal presentation, epidural anesthesia, prolonged first/second stage of labor, and forceps delivery after a failed vacuum. CONCLUSIONS: Identification of risk factors for PPH after a vaginal delivery may afford prophylactic treatment of such women with reduction of morbidity.

Adolescent↗

PubMed2005

Postpartum hemorrhage after cesarean delivery: an analysis of risk factors.

OBJECTIVE: To determine the incidence and risk factors for postpartum hemorrhage (PPH) associated with cesarean delivery. METHODS: Blood loss at cesarean delivery was measured and defined as 1,000 to 1,499 mL or greater than 1,500 mL and/or the need for a blood transfusion. Variables were identified and evaluated to determine the factors associated with PPH. RESULTS: There were 1,844 elective and 2,993 nonelective cesarean deliveries over 4 years. The PPH rate in nonelective cesarean (6.75%) was greater than after elective cesarean (4.84%, P = 0.007). Risk factors for PPH after an elective operation included leiomyomata, blood disorders, placenta previa, antepartum bleeding, preterm birth, and general anesthesia. Nonelective cesarean PPH risk factors included blood disorders, retained placenta, antepartum transfusion, antepartum/intrapartum hemorrhage, placenta previa, general anesthesia, and macrosomia (odds ratio > 1.5, confidence interval > 1.5). CONCLUSIONS: Nonelective cesarean deliveries have a higher risk of PPH than women delivered electively. Risk factor identification and prevention should be a priority.

Adult↗

PubMed2005

Evaluation of inducible nitric oxide synthase in glaucomatous optic neuropathy and pressure-induced optic nerve damage.

PURPOSE: To determine whether inducible nitric oxide synthase (NOS-2) is involved in glaucomatous optic neuropathy. METHODS: Chronic elevation of rat intraocular pressure (IOP) leading to optic nerve damage was induced by episcleral injection of hypertonic saline, which caused sclerosis and blockade of aqueous humor outflow pathways. Expression of NOS-2 in the retina and optic nerve head (ONH) was evaluated by immunohistochemistry, gene array analysis, and quantitative PCR (Q-PCR). Immunohistochemistry was also used to assess the NOS-2 level in the ONH from primary open-angle glaucoma (POAG) and nonglaucomatous human eyes. Finally, an NOS-2 inhibitor, aminoguanidine, administered orally in the drinking water, was tested for its effect on optic nerve injury in rats with ocular hypertension. RESULTS: Chronically elevated IOP in the rat produced optic nerve damage that correlated with pressure change (r(2) = 0.77), but did not increase NOS-2 immunoreactivity in the optic nerve, ONH, or ganglion cell layer. Retinal and ONH NOS-2 mRNA levels did not correlate with either IOP level or severity of optic nerve injury. Similarly, there was no difference in NOS-2 immunoreactivity in the optic nerve or ONH between POAG and nonglaucomatous eyes. Furthermore, aminoguanidine treatment did not affect the development of pressure-induced optic neuropathy in the rat. CONCLUSIONS: As demonstrated by several independent methods, glaucomatous optic neuropathy was not associated with a significant change in the expression of NOS-2 in the retina, ONH, or optic nerve.

Aged↗

PubMed2005

Absent or reversed end-diastolic flow in the umbilical artery: outcome at a community hospital.

OBJECTIVE: To describe the peripartum outcome and risk factors for neonatal death among pregnancies complicated with umbilical arterial absent end diastolic or reverse flow (AREDF UA), in a community hospital. STUDY DESIGN: The inclusion criteria of this retrospective analysis were: AREDF UA detected and managed at a community hospital. RESULTS: During the 46 months, 50 cases of AREDF UA were detected and the pregnancies were complicated by hypertensive disease in 52%, twins in 26%, and diabetes mellitus in 14%. Excluding four (8%) stillbirths of non-anomalous fetuses, nine newborns died and the significant differences between those who died and lived (n = 36) were: oligohydramnios (odds ratio [OR] 34.00, 95% confidence intervals [CI] 4.65, 248.50), non-immune hydrops (OR 24.33, 95% CI 1.01, 560.60) and respiratory distress syndrome (OR 7.00, 95% CI 1.27, 38.59). CONCLUSIONS: The risk factors for neonatal mortality with AREDF UA are oligohydramnios, non-immune hydrops, or respiratory distress syndrome.

Blood Flow Velocity↗

PubMed2005

Well-differentiated papillary mesothelioma of the uterine serosa identified at cesarean section: a case report.

BACKGROUND: Peritoneal mesotheliomas encompass a variety of benign and malignant neoplasms. Well-differentiated papillary mesothelioma (WDPM) is uncommon, is thought to be of low malignant potential and is often discovered incidentally during abdominal or pelvic surgery. We describe a highly unusual case in which WDPM arising from the uterine serosa was identified at the time of cesarean delivery. CASE: A 21-year-old primigravida underwent cesarean delivery at term for arrest of the active phase of labor. A 2-cm, polypoid lesion was excised from the posterior uterine fundus; final pathology showed well-differentiated papillary mesothelioma. Subsequent examination and computed tomography were negative. A follow-up laparoscopic examination with abdominal washing for cytology and peritoneal biopsies revealed no residual disease. CONCLUSION: Survey of the pelvic cavity during cesarean section is important. Knowledge of the variable disease spectrum of mesothelioma is important in patient counseling and management. Differentiating between WDPM and malignant mesothelioma, other peritoneal tumors and implants from primary sites is necessary to avoid overtreatment.

Adult↗

PubMed2005

Excessive uterine contractions: effect on the incidence of preterm delivery in twin gestation.

OBJECTIVE: To evaluate the effect of uterine contractions on the incidence of preterm delivery within 7 and 14 days in twin pregnancies. STUDY DESIGN: Study patients were identified from a large database composed of women receiving outpatient surveillance with home uterine contraction monitoring. We included tracings collected on a routine or acute basis from twin pregnancies without cerclage at 24.0-36.0 weeks. Tracings from patients with indicated delivery were excluded. Fisher's exact and Pearson's X2 tests were used. RESULTS: Datafrom 2,423 patients who recorded 8,291 acute tracings and 12,649 routine tracings were analyzed. Preterm delivery within 7 days followed 1.4% of routine vs. 6.6% of acute tracings (p < 0.001). Preterm delivery within 14 days followed 5.1% of routine vs. 16.8% of acute tracings (p < 0.001). CONCLUSION: Preterm uterine contractions affect pregnancy prolongation and outcome in twin pregnancies utilizing outpatient surveillance. Evaluation of patients exhibiting elevated preterm uterine contractions is warranted.

Adult↗

PubMed2005

Diagnostic imaging in uterine incisional necrosis/dehiscence complicating cesarean section.

OBJECTIVE: To review the diagnostic imaging studies in patients with surgically proven uterine incisional necrosis/dehiscence complicating cesarean section and to compare these studies with the findings at surgery. STUDY DESIGN: Over a 6-year period, the records of 7 patients with imaging studies prior to surgery for uterine incisional necrosis/dehiscence complicating cesarean delivery were reviewed and compared with the findings at surgery. RESULTS: Four cases underwent computed tomography (CT) and sonography, 1 underwent CT only, and 2 underwent sonography only. Abnormal findings included abdominal free fluid in 4, pleural effusions in 3, dilated bowel in 3, possible bladder flap hematoma in 2 and single instances of liver abscess and retained products of conception. In no cases were all the studies normal, and necrosis/dehiscence was not demonstrated in any patient. CONCLUSION: Abdominal free fluid, bowel distension, pleural effusion and bladder flap hematoma seen on CT or sonogram in the postcesarean context suggest the possibility of uterine incisional necrosis/dehiscence. Magnetic resonance imaging (MRI) might then be indicated since MRI may be superior to CT in evaluating complications at the incisional site because of its multiplanar capability and greater degree of soft tissue contrast.

Ascitic Fluid↗

PubMed2004

A randomized clinical trial of the intrapartum assessment of amniotic fluid volume: amniotic fluid index versus the single deepest pocket technique.

OBJECTIVE: The purpose of this study was to determine whether an intrapartum assessment of amniotic fluid identifies a pregnancy that is at risk for an adverse outcome. STUDY DESIGN: Parturients who were admitted for delivery were assigned randomly to have the amniotic fluid assessed either by amniotic fluid index or by the presence of a 2 x 1 pocket. RESULTS: The amniotic fluid index was obtained in 499 pregnancies, and the 2 x 1 technique was performed in 501. Oligohydramnios was diagnosed in 25% of amniotic fluid index pregnancies versus 8% with the use of the 2 x 1 pocket technique (P <.001). Both techniques failed to identify patients who underwent an amnioinfusion for fetal distress (P=.864) or who experienced variable (P=.208) or late decelerations (P=.210) that influenced delivery, fetal distress in labor (P=.220), caesarean delivery for fetal distress (P=.133), and admission to neonatal intensive care unit (P=.686). CONCLUSION: Neither the amniotic fluid index nor the 2 x 1 pocket technique that was undertaken as a fetal admission test identifies a pregnancy that is at risk for an adverse outcome.

Adult↗

PubMed2004

Fetal fibronectin and bacterial vaginosis are associated with preterm birth in women who are symptomatic for preterm labor.

OBJECTIVE: The purpose of this study was to codify the relationship between bacterial vaginosis/fetal fibronectin and preterm labor/birth. STUDY DESIGN: In this prospective study, 185 women who were symptomatic for preterm labor were assessed for bacterial vaginosis and fetal fibronectin. RESULTS: These women comprised 4 groups: group A (n=23 women; +bacterial vaginosis/+fetal fibronectin); group B (n=31 women; -bacterial vaginosis/+fetal fibronectin); group C (n=47 women; +bacterial vaginosis/-fetal fibronectin); and group D (n=84 women; -bacterial vaginosis/-fetal fibronectin). The time interval from gestational age at testing until delivery was significantly shorter for groups A and B versus groups C and D (P < or =.05 and P <.001, respectively). Similarly, delivery at <32 weeks of gestation was increased in group B (26%) compared with groups A (9%), C (2%), and D (5%; P <.009; odds ratio, 165.90; 95% CI, 30.02, 916.08). CONCLUSION: Women who are symptomatic for preterm labor should be considered for fetal fibronectin and bacterial vaginosis testing.

Adult↗

PubMed2004

Is there a relationship to dye determined or ultrasound estimated amniotic fluid volume adjusted percentiles and fetal weight adjusted percentiles?

OBJECTIVE: This study was undertaken to determine whether there is a correlation between neonatal birth weight and an estimated or dye-determined amniotic fluid volume. STUDY DESIGN: A prospective observational study of women undergoing an amniocentesis and subsequent delivery within 72 hours. Amniotic fluid volume was estimated using the amniotic fluid index (AFI) and single deepest pocket technique and calculated by the dye-dilution technique. RESULTS: One hundred seventy-five women participated in the study. Linear regression modelling showed no significant relationship between birth weight and amniotic fluid volume adjusted for gestational age (P=.062). Similarly, there was no evidence of an association between birth weight and a dye determined amniotic fluid volume (P=.180), fixed cutoffs for the AFI (P=.224), percentiles for the AFI (P=.112), or fixed cutoffs for the single deepest pockets (P=.867). CONCLUSION: Neonatal birth weight is not correlated with a dye-determined or ultrasound estimated amniotic fluid volume.

Adolescent↗

PubMed2004

How well do the amniotic fluid index and single deepest pocket indices (below the 3rd and 5th and above the 95th and 97th percentiles) predict oligohydramnios and hydramnios?

OBJECTIVE: This study was undertaken to determine whether the amniotic fluid index (AFI) and single deepest pocket percentiles can reliably identify a dye-determined amniotic fluid volume. STUDY DESIGN: Ultrasound measurements and dye-determined volumes were prospectively collected. Oligohydramnios predictors included AFI and single deepest pocket below the 3rd and 5th percentiles, and hydramnios predictors were based on AFI and single deepest pocket above the 95th and 97th percentiles. RESULTS: Two hundred ninety-one women with singleton pregnancies participated, including 75 pregnancies (26%) with oligohydramnios and 31 pregnancies (10%) with hydramnios. The predictive ability of the AFI and single deepest pocket indices (<3rd and 5th percentiles) to identify oligohydramnios was between 11% and 27% and to identify hydramnios (>95th and 97th percentiles) ranged between 33% and 46%. The best prediction was for normal fluid volume with an accuracy of 83% to 94%. CONCLUSION: Amniotic fluid indices perform best for the identifying normal AF volumes, whereas the identification of oligohydramnios or hydramnios is poor.

Adult↗

PubMed2004

Dye-determined amniotic fluid volume and intrapartum/neonatal outcome.

OBJECTIVE: To ascertain if a dye-determined amniotic fluid volume was predictive of intrapartum and perinatal outcome. MATERIALS AND METHODS: The low and normal amniotic fluid volumes (< 5th percentile and > or =5th percentile for gestational age) and the raw dye-determined amniotic fluid distributions were correlated with 10 clinical outcome measures in 74 pregnancies. RESULTS: In this observational study, median gestational age at delivery was 36 weeks (range 26 to 41) and 16 deliveries were for fetal distress (14 Cesarean and two forceps). There were no differences between the outcomes of pregnancies with low and normal amniotic fluid volumes for any of the clinical outcomes (variable decelerations influencing delivery, p=0.381; late decelerations, p=0.875; Cesarean births for fetal intolerance of labor, p=0.259; intrauterine growth restriction, p=0.998; or umbilical cord arterial pH< 7.2, p=0.259). Analogous results were obtained when the gestational age-adjusted amniotic fluid volumes were compared directly between the pregnancies with normal and abnormal outcomes. There was no difference between the mean amniotic fluid volumes in those pregnancies with variable decelerations influencing delivery (p=0.287), late decelerations (p=0.555), Cesarean births for fetal intolerance of labor (p=0.310), intrauterine growth restriction (p=0.267) or umbilical cord arterial pH< 7.2, and the pregnancies without these intrapartum events. Reduced variability was more commonly observed in pregnancies with higher amniotic fluid volumes (p=0.038, 771 ml, 95% CI 468 to 1269, compared to those without normal variability 444 ml, 95% CI 374 to 526). CONCLUSIONS: Dye-determined amniotic fluid volume does not appear to be predictive of adverse intrapartum and neonatal outcome.

Adolescent↗

PubMed2004

Umbilical arterial pH < 7.00 in newborns delivered by nonelective cesarean delivery: risk factors and peripartum outcomes.

The objective of this study was to compare the risk factors and peripartum outcomes among patients who had nonelective cesarean delivery with umbilical arterial pH < versus > or = 7.00. A case-control study of parturients who delivered by nonelective cesarean delivery and had a neonate with a pH < 7.00 were compared with the next four patients who delivered abdominally but had a newborn with a normal pH. Among 45 newborns with pH < 7.00 the rate of cesarean delivery for nonreassuring fetal heart rate was significantly more common in the case (56%) than control group (16%). The rates of end organ failure and neonatal death were similar for both groups. Although newborns with pH < 7.00 were significantly more likely to have cesarean delivery for nonreassuring fetal heart rate patterns and be admitted to the neonatal intensive care unit, there was no means to identify these patients until the abnormalities in tracing developed.

Acidosis↗

PubMed2004

Conservative surgery for uterine incisional necrosis complicating cesarean delivery.

BACKGROUND: Hysterectomy is the usual management of uterine incisional necrosis with dehiscence as a complication of cesarean delivery. Debridement with resuture of the uterine wound as an alternative therapy would conserve fertility at the risk of continued necrosis and infection. Unfortunately the literature provides few guidelines in deciding when to select conservative surgery and whether it is a safe option. CASES: Three cases are presented with uterine incisional necrosis complicating cesarean delivery. In 2 instances, uterine conservation was considered an acceptable option and was successfully completed. The third patient underwent hysterectomy because of clinical features deemed to be contraindications to conservative surgery. CONCLUSION: In well-selected patients, debridement and resuture of the uterine incision is an acceptable alternative to hysterectomy for uterine incisional necrosis.

Adolescent↗

PubMed2004

Biophysical profile with amniotic fluid volume assessments.

OBJECTIVE: To compare the amniotic fluid index (AFI) with the single deepest pocket technique along with the other components of the biophysical profile (BPP) in predicting an adverse pregnancy outcome. METHODS: Prospective, randomized trial of amniotic fluid assessment by AFI or single deepest pocket during a BPP. Cesarean delivery for fetal distress was the primary outcome evaluated. RESULTS: The AFI was used in 273 pregnancies and the single deepest pocket in 264. The AFI significantly increased the number of pregnancies labeled as oligohydramnios, 102 women (38%) compared with 46 women (17%; P <.001), odds ratio (OR) = 2.84, 95% confidence interval 1.90-4.25 in the single deepest pocket group. There was no difference in the number of women with oligohydramnios in the AFI group, 16 of 102 (16%), undergoing a cesarean delivery for fetal intolerance of labor compared with the single deepest pocket group, 6 of 46 (13%; P =.676). More women with normal fluid by the AFI method (AFI > 5), 20 of 170 (12%), underwent a cesarean delivery for fetal distress than the women with normal fluid by the single deepest pocket technique (2 cm x 1 cm pocket present) group, 12 of 218 (6%; P =.037, OR = 2.22, 95% confidence interval 1.05-4.70). CONCLUSION: The AFI offers no advantage in detecting adverse outcomes compared with the single deepest pocket when performed with the BPP. The AFI may cause more interventions by labeling twice as many at-risk pregnancies as having oligohydramnios than with the single deepest pocket technique.

Amniotic Fluid↗