Ultrasonographic study of ductus venosus in healthy neonates

AIM—To assess ultrasonographically the flow pattern and the time of postnatal closure of ductus venosus related to the other fetal shunts.
METHODS—Fifty healthy, term neonates were studied from day 1 up to day 18 using a VingMed CFM 800A ultrasound scanner.
RESULTS—Ductus arteriosus was closed in 94% of the infants before day 3. Ductus venosus, however, was closed in only 12% at the same time, in 76% before day 7, and in all infants before day 18. A closed ductus venosus or ductus arteriosus did not show signs of reopening. Pulsed and colour Doppler flow could be detected across the foramen ovale in all infants during the sequential investigation. At day 1, when the pulmonary vascular resistance was still high, a reversed Doppler flow velocity signal was seen in ductus venosus in 10 infants (20%) and a bidirectional flow in ductus arteriosus in 26 (52%). Closure of the ductus venosus was not significantly correlated with closure of the ductus arteriosus nor related to sex nor weight loss.
CONCLUSIONS—The time of closure of the ductus venosus evaluated by ultrasonography is much later than that of the ductus arteriosus. The flow pattern in ductus venosus reflects the portocaval pressure gradient and the pressure on the right side of the heart and in the pulmonary arteries. Both the flow pattern in the ductus venosus as well as that in the ductus arteriosus may be an indication of compromised neonatal haemodynamics.

     

A national study on conditional survival,excess mortality and second cancer after high dose therapy with autologous stem cell transplantation for non‐Hodgkin lymphoma

This national population‐based study aimed to investigate conditional survival and standardized mortality ratios (SMR) after high‐dose therapy with autologous stem‐cell transplantation (HDT‐ASCT) for non‐Hodgkin lymphoma (NHL), and to analyse cause of death, relapses and second malignancies. All patients ≥18 years treated with HDT‐ASCT for NHL in Norway between 1987 and 2008 were included (n = 578). Information from the Cause of Death Registry and Cancer Registry of Norway were linked with clinical data. The 5‐, 10‐ and 20‐year overall survival was 61% (95% confidence interval [CI] 56–64%), 52% (95%CI 48–56%) and 45% (95%CI 40–50%), respectively. The 5‐year survival conditional on having survived 2, 5 and 10 years after HDT‐ASCT was 81%, 86% and 93%. SMRs were 12·3 (95%CI 11·0–13·9), 4·9 (95%CI 4·1–5·9), 2·4 (95%CI 1·8–3·2) and 1·0 (95%CI 0·6–1·8) for the entire cohort and for patients having survived 2, 5 and 10 years after HDT‐ASCT respectively. Of the 281 deaths observed, 77% were relapse‐related. Treatment‐related mortality was 3·6%. The 10‐year cumulative incidence of second malignancies was 7·9% and standardized incidence ratio was 2·0 (95%CI 1·5–2·6). NHL patients treated with HDT‐ASCT were at increased risk of second cancer and premature death. The mortality was still elevated at 5 years, but after 10 years mortality equalled that of the general population.     

Physiology of the fetal circulation

Our understanding of fetal circulatory physiology is based on experimental animal data, and this continues to be an important source of new insight into developmental mechanisms. A growing number of human studies have investigated the human physiology, with results that are similar but not identical to those from animal studies. It is time to appreciate these differences and base more of our clinical approach on human physiology. Accordingly, the present review focuses on distributional patterns and adaptational mechanisms that were mainly discovered by human studies. These include cardiac output, pulmonary and placental circulation, fetal brain and liver, venous return to the heart, and the fetal shunts (ductus venosus, foramen ovale and ductus arteriosus). Placental compromise induces a set of adaptational and compensational mechanisms reflecting the plasticity of the developing circulation, with both short- and long-term implications. Some of these aspects have become part of the clinical physiology of today with consequences for surveillance and treatment.     

A randomized, controlled trial comparing effect of oral misoprostol and intravenous syntocinon on intra-operative blood loss during cesarean section

BACKGROUND: Oxytocics are routinely used in an attempt to prevent excessive blood loss during cesarean section. Misoprostol, a potent uterotonic agent, has been reported to be useful in the prevention and treatment of postpartum hemorrhage by several investigators but its use during cesarean section has not been described. The objective of this study was to randomly compare the effectiveness of oral misoprostol with intravenous syntocinon on blood loss during elective cesarean sections under regional anesthesia. METHODS: Sixty pregnant women were randomized either to receive misoprostol 400 micrograms orally or syntocinon 10 IU intravenously during cesarean section. The primary outcome measure was intra-operative blood loss as estimated by physicians, and by values of preoperative and postoperative hemoglobin concentration and hematocrit. Demographic characteristics of the subjects and outcomes were compared using chi-square test for categorical and two-sample t-test for continuous data. RESULTS: Baseline characteristics in terms of age, body weight, parity, gestational age and indications for cesarean section were similar in both groups. The estimated blood loss was 545 ml (CI 476-614) in misoprostol group and 533 ml (CI 427-639) in syntocinon group (p = 0.85). Differences in preoperative and postoperative hemoglobin and hematocrit values were also similar in both groups. Two women in the misoprostol group and three in the syntocinon group (p=0.64) required additional oxytocics. One patient in each group required blood transfusion. No serious side effects were noted in either group. CONCLUSION: Oral misoprostol appears to be safe and as effective as intravenous syntocinon in reduction of intra-operative blood loss during elective cesarean section under regional anesthesia and merits further investigation.     

Pulsations of the ductus venosus blood velocity and diameter are more pronounced at the outlet than at the inlet.

OBJECTIVE: To test the hypothesis that the pulse wave emitted from the heart into the precordial veins is altered as it travels towards the periphery. STUDY DESIGN: Ultrasound diameter measurement and Doppler recording at the inlet and outlet of the fetal ductus venosus in 20 normal pregnancies (gestational age 19-41 weeks) were used to compare velocity patterns and diameters applying paired t-test and Spearman's rank correlation. RESULTS: There was a significantly lower pulsatility of the blood velocity in the ductus venosus at the inlet compared to the outlet, and, correspondingly, there was a significantly smaller diameter pulsation at the inlet than at the outlet. CONCLUSION: Both blood velocity and diameter pulsations are smaller at the inlet than at the outlet of the ductus venosus. The tapering shape of the vessel and the diameter differences at the junction with the umbilical vein are suggested to be important factors affecting the velocity waveform.     

Ductus venosus blood velocity in persistent pulmonary hypertension of the newborn.

AIMS: To investigate the ductus venosus flow velocity (DVFV) in infants with persistent pulmonary hypertension of the newborn (PPHN); to evaluate the DVFV pattern as a possible diagnostic supplement in neonates with PPHN and other conditions with increased right atrial pressure. METHODS: DVFV was studied in 16 neonates with PPHN on days 1-4 of postnatal life using Doppler echocardiography. DVFV was compared with that in mechanically ventilated neonates with increased intrathoracic pressure, but without signs of PPHN (n=11); with neonates with congenital heart defects resulting in right atrial pressure (n=6); and with preterm neonates without PPHN (n=46); and healthy term neonates (n=50). RESULTS: Infants with PPHN and congenital heart defects with increased right atrial pressure were regularly associated with an increased pulsatile pattern and a reversed flow velocity in ductus venosus during atrial contraction. A few short instances of reversed velocity were also noted in normal neonates before the circulation had settled during the first day after birth. CONCLUSIONS: A reversed velocity in the ductus venosus during atrial contraction at this time signifies that central venous pressure exceeds portal pressure. This negative velocity deflection is easily recognised during Doppler examination and can be recommended for diagnosing increased right atrial pressure and PPHN.