Peripartum management of a parturient with type 1C (clearance) von Willebrand disease.

Peripartum replacement of factor VIII and von Willebrand factor is not usually required in type 1 von Willebrand disease, as the levels of endogenous factors tend to increase to within the normal range as a physiological change of pregnancy. However, there is wide heterogeneity of genotypes and phenotypes associated with type 1 von Willebrand disease. Here, we describe the anesthetic management of a parturient with type 1C von Willebrand disease, a subtype characterized by decreased plasma von Willebrand factor survival.

The comparative accuracy of a handheld and console ultrasound device for neuraxial depth and landmark assessment.

BACKGROUND: The study aimed to compare the accuracy of epidural depth estimation of a handheld ultrasound device, with an integrated algorithm that estimates epidural depth (AU; Accuro, Rivanna Medical), to that of a console ultrasound machine (GU; GE LOGICTM S8). METHODS: Women requesting labor epidural analgesia consented to this prospective cohort study. The L2/3, L3/4, and L4/5 interspaces and the respective depths to the epidural space were identified, marked and measured using an AU and GU. An anesthesia provider who was blinded to ultrasound depth measurements performed epidural analgesia at one of the ultrasound identified insertion points and recorded the Tuohy needle depth at loss-of-resistance. Bland Altman analysis was used to measure the agreement between the epidural depths measured by the AU and GU. RESULTS: A total of 47 women were analyzed. The mean ±â€¯standard deviation body mass index of the study cohort was 29 ±â€¯5 kg/m2 [range 23-45]. The mean difference between the epidural depths measured by the AU and GU was -0.29 cm [95% limit of agreement 0.50 to -0.91]. The mean difference between the depth to the epidural space measured by the GU versus the needle depth was -0.33 cm [95% CI -0.49 to -0.16]. The previously reported AU versus needle depth was -0.61 cm [95% CI -0.79 to -0.44]. CONCLUSION: The AU and GU provided comparable epidural depth estimates. The AU device may be a reasonable alternative to more sophisticated ultrasound devices in determining the epidural space and depth in a non-obese obstetric population.

Obstetric interventions and maternal morbidity among women who experience severe postpartum hemorrhage during cesarean delivery.

BACKGROUND: Compared to vaginal delivery, women undergoing cesarean delivery are at increased risk of postpartum hemorrhage. Management approaches may differ between those undergoing prelabor cesarean delivery compared to intrapartum cesarean delivery. We examined surgical interventions, blood component use, and maternal outcomes among those experiencing severe postpartum hemorrhage within the two distinct cesarean delivery cohorts. METHODS: We performed secondary analyses of data from two cohorts who underwent prelabor cesarean delivery or intrapartum cesarean delivery at a tertiary obstetric center in the United States between 2002 and 2012. Severe postpartum hemorrhage was classified as an estimated blood loss ≥1500mL or receipt of a red blood cell transfusion up to 48h post-cesarean delivery. We examined blood component use, medical and surgical interventions and maternal outcomes. RESULTS: The prelabor cohort comprised 269 women and the intrapartum cohort comprised 278 women. In the prelabor cohort, one third of women received red blood cells intraoperatively or postoperatively, respectively. In the intrapartum cohort, 18% women received red blood cells intraoperatively vs. 44% postoperatively (P<0.001). In the prelabor and intrapartum cohorts, methylergonovine was the most common second-line uterotonic (33% and 43%, respectively). Women undergoing prelabor cesarean delivery had the highest rates of morbidity, with 18% requiring hysterectomy and 16% requiring intensive care admission. CONCLUSION: Our findings provide a snapshot of contemporary transfusion and surgical practices for severe postpartum hemorrhage management during cesarean delivery. To determine optimal transfusion and management practices in this setting, large pragmatic studies are needed.

Floral transition and nitric oxide emission during flower development in Arabidopsis thaliana is affected in nitrate reductase-deficient plants.

The nitrate reductase (NR)-defective double mutant of Arabidopsis thaliana (nia1 nia2) has previously been shown to present a low endogenous content of NO in its leaves compared with the wild-type plants. In the present study, we analyzed the effect of NR mutation on floral induction and development of A. thaliana, as NO was recently described as one of the signals involved in the flowering process. The NO fluorescent probes diaminofluorescein-2 diacetate (DAF-2DA) and 1,2-diaminoanthraquinone (1,2-DAA) were used to localize NO production in situ by fluorescence microscopy in the floral structures of A. thaliana during floral development. Data were validated by incubating the intact tissues with DAF-2 and quantifying the DAF-2 triazole by fluorescence spectrometry. The results showed that NO is synthesized in specific cells and tissues in the floral structure and its production increases with floral development until anthesis. In the gynoecium, NO synthesis occurs only in differentiated stigmatic papillae of the floral bud, and, in the stamen, only anthers that are producing pollen grains synthesize NO. Sepals and petals do not show NO production. NR-deficient plants emitted less NO, although they showed the same pattern of NO emission in their floral organs. This mutant blossomed precociously when compared with wild-type plants, as measured by the increased caulinar/rosette leaf number and the decrease in the number of days to bolting and anthesis, and this phenotype seems to result from the markedly reduced NO levels in roots and leaves during vegetative growth. Overall, the results reveal a role for NR in the flowering process.

Nature of heart failure in patients with ventricular septal defect.

To assess the contributions of systolic and diastolic dysfunction to congestive heart failure (CHF) in ventricular septal defect (VSD), we studied 13 children with VSD at catheterization using a Millar catheter. Eight children had CHF, whereas five did not. Phenylephrine was infused at a rate of 5 micrograms.kg-1.min-1, and M-mode echocardiography and pressure were measured simultaneously. Systolic left ventricular (LV) function was assessed by maximum LV pressure (LVP), rate of pressure development (dP/dt), and by the end-systolic pressure-diameter relation (ESPDR). Systolic myocardial function was assessed by the end-systolic stress-strain relation. Diastolic chamber function was assessed by the isovolumic relaxation time constant (tau) and by the end-diastolic pressure-diameter relation (EDPDR). Diastolic myocardial function was measured by the end-diastolic stress-strain relationship. With phenylephrine, maximum LVP increased from 99 +/- 5 to 119 +/- 4 mmHg with CHF and from 106 +/- 6 to 149 +/- 10 mmHg without CHF. +dP/dt was lower with CHF (1,582 +/- 96 mmHg/s) than without CHF (2,300 +/- 200 mmHg/s). The maximum slope of the ESPDR was 39 +/- 8 with CHF and 94 +/- 14 mmHg/cm without CHF. The maximum slope of the midwall stress-strain relation was 223 +/- 37 with CHF and 395 +/- 93 g/cm2 without CHF. tau was 25 +/- 2 without CHF compared with 32 +/- 3 ms with CHF. The EDPDR was shifted leftward with failure, whereas the stress-strain relation was similar for all patients. CHF in patients with VSD results primarily from systolic dysfunction.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of vasopressin and atrial natriuretic factor in postoperative fluid retention after the Fontan procedure.

The Fontan procedure results in right atrial distention and is complicated by fluid retention. Since systemic fluid balance may be hormonally mediated in part and related to right atrium size, we measured plasma atrial natriuretic factor and plasma arginine vasopressin levels in 19 patients undergoing the Fontan procedure and in 12 control patients undergoing other types of heart operations. Preoperative plasma atrial natriuretic factor levels were higher in patients undergoing the Fontan procedure than in control patients (95 +/- 16 pg/ml preoperatively versus 50 +/- 8 pg/ml; p less than 0.05) and increased in patients undergoing the Fontan procedure to 330 +/- 48 pg/ml by postoperative day 2 (p less than 0.05) but not in control patients. Increased plasma atrial natriuretic factor levels could enhance capillary transudation, but elevated plasma atrial natriuretic factor levels should also enhance diuresis and prevent fluid retention. Vasopressin levels, however, were also increased in patients undergoing the Fontan procedure (from 9 +/- 2 pg/ml preoperatively to 144 +/- 37 pg/ml at end of operation) and were higher and remained elevated longer than in control patients undergoing heart operations (37 +/- 7, 20 +/- 4, 16 +/- 6 pg/ml on postoperative days 1, 2, and 3 to 10 for the Fontan group compared with 15 +/- 4, 4 +/- 1, 4 +/- 2 pg/ml for control patients). Vasopressin levels were highest in the Fontan group with the most severe fluid retention and effusions (for example, 51 +/- 10 pg/ml versus 23 +/- 4 pg/ml, on postoperative day 1). Increased vasopressin and atrial natriuretic factor could act synergistically to result in the development of effusions after the Fontan procedure when atrial natriuretic factor-induced capillary transudation is combined with vasopressin-induced antidiuresis.

Elevated atrial natriuretic peptide after the Fontan procedure.

To assess the response of atrial natriuretic peptide (ANP) to rapidly changing right atrial pressures in vivo, we measured ANP levels in 15 patients undergoing the Fontan procedure and compared them with control levels in nine patients undergoing cardiac surgery for lesions not associated with atrial hypertension. There were no significant differences in preoperative ANP levels: 57 +/- 15 pg/ml for patients undergoing the Fontan procedure, 43 +/- 8 pg/ml for control patients. There was no significant change in ANP during surgery or in the postoperative period in control patients. In contrast, ANP increased significantly to 333 +/- 70 pg/ml (p less than .0025) after establishment of right atrial-pulmonary artery continuity with the Fontan procedure and was related to right atrial pressure, which increased from 5 mm Hg before to 14 mm Hg after the Fontan procedure (p less than .001). There was no significant change in left atrial pressure. During the first postoperative day, ANP levels fell to 141 +/- 34 pg/ml (p less than .01) but later increased to 290 +/- 80 pg/ml (p less than .025), a finding that may suggest depletion of a readily releasable intracellular pool of ANP before mobilization of a storage pool. There was no direct relationship between ANP levels and effusions in patients undergoing the Fontan procedure. Pharmacologically significant increases in ANP occur in patients undergoing the Fontan procedure, correlating with increased right atrial pressures, but the relationship between ANP and the fluid derangements after the procedure remains unclear.

The separation of different cell classes from lymphoid organs. 3. Te purfication of erythroid cells by pH-induced density changes.

1. Mammalian erythrocytes swell as the pH of the isotonic suspending medium is lowered, as a direct consequence of the specialized permeability properties of the erythrocyte membrane. Lymphocytes and granulocytes from a variety of sources did not exhibit this property. 2. The behaviour of mouse bone marrow erythroid cells at various stages of differentiation was studied by using a change in buoyant density with pH as an index of swelling. The ability to swell with a pH drop was acquired while the cell was still nucleated. All non-nucleated cells showed swelling. Most small erythroblasts shared this property, whereas most large erythroblasts did not. 3. The density shift with pH was used to provide a purification scheme specific for erythroid cells. The bone marrow cells were first centrifuged to equilibrium in an isotonic albumin density gradient at neutral pH. Regions of the gradient containing the erythroid cells were collected, and the cells were recovered and redistributed in an albumin gradient at acid pH. The erythroid cells showed a specific density shift which removed them from contaminants. Preparations containing 90-97% erythroblasts were obtained by this technique. 4. Differentiation within the erythroid series was accompanied by a general increase in cell buoyant density at neutral pH. This density increase may have been a discontinuous process, since erythroid cells appeared to form a number of density peaks. 5. The pH shift technique, in association with established density distribution and sedimentation velocity procedures, provides a range of cell separation techniques for biological or biochemical studies of erythroid cell differentiation in the complex cell mixtures in bone marrow or spleen.