Usefulness of Serum Brain Natriuretic Peptide Level for Screening Hemodynamically Significant Patent Ductus Arteriosus in Preterm Neonates

Objective:

We studied usefulness of serum B-type natriuretic peptide level as a screening tool for detecting hemodynamically significant patent ductus arteriosus in the preterm neonates.

Methods:

Sixty admitted preterm neonates with gestational age ≤34 weeks, birth weight ≤2500 gr, and age of >3 days have been enrolled in this study. We measured serum B-type natriuretic peptide levels at the beginning and after completion of drug therapy for ductus occlusion.

Findings:

Mean±SD gestational age and weight was 31±1.9 weeks and 1680±350 gr, respectively. The peptide levels in the neonates with significant duct (n=13) were significantly higher than in those with insignificant duct (n=17) or no duct (n=30) (1667±821 pg/ml versus 667±666 and 309±171, respectively). The peptide level dropped significantly after ibuprofen administration in the neonates with significant PDA (n=13), (1667±1165 pg/ml to 429±386).

Conclusion:

At a cutoff point of 450 pg/ml, B-type natriuretic peptide level had a sensitivity of 92% and specificity of 87%, the negative predictive value of 98.5%, the positive likelihood ratio of 6.92 and the negative likelihood ratio of 0.089 for detecting significant patent duct. Levels below this can eliminate the need for echocardiography.     

Effect of daily and intermittent iron supplementation on iron status of high school girls

This experimental study was designed to investigate the effects of daily versus intermittent iron supplementation on iron status of high school girls in Zahedan and Rasht cities in 1996-1997. The subjects were selected randomly from among students of grades 1-3 of four high schools in each city. Anemia was determined by measuring hematological indices. 260 anemic and a similar number of non-anemic subjects of 4 high schools were selected and allocated randomly to 4 treatment groups. During a 3-month period, the test groups were given 150 mg ferrous sulfate tablets (50 mg Fe). Subjects in group 1 received a daily dose, groups 2 & 3 received twice or once weekly doses respectively. The control group received no iron supplement. For these subjects, in addition to hematological indices biochemical iron indices were measured in the beginning and at the end of the study. The increases in hemoglobin concentration in anemic subjects were not significantly different among supplemented groups but were different from the control group (p < 0.00001). Among anemic subjects, changes in serum ferritin levels in 3 supplemented groups were significantly different from the control group. Serum ferritin in Group 1 was also increased to a greater extent than groups 2 and 3 (P < 0.00001). It is concluded that over the study period a weekly iron dose was as effective as a daily dose in treating anemia but the daily dose was more effective in improving iron stores than a weekly dose in the short run.     

Measurement of extravascular lung water in hemodialysis patients using blood ultrasound velocity and optical density dilution

In hemodialysis patients, volume homeostasis is an important clinical problem. The aim is to have patients at an ideal "dry weight" postdialysis, but current methods for accurately measuring dry weight are disappointing. Krivitski et al. (ASAIO J 1998;44:M535-M540) have described a novel technique whereby extravascular lung water (EVLW) may be measured using blood ultrasound velocity and electrical impedance dilution. They have tested this method in animals and achieved agreement between obtained versus gravimetric measurements. Isotonic saline is used as a nondiffusible indicator and hypertonic (5%) saline is used as a diffusible indicator. By injecting these solutions and following their transits through the cardiopulmonary circulation, a theoretic basis for the calculation of EVLW may be derived from the cardiac output, the water transferred to blood, the amount of sodium chloride moved from blood to lung, and the increase in blood osmolality measured at the moment of osmotic equilibrium. We have used this new technique to measure EVLW for the first time in humans in 18 stable hemodialysis patients with no cardiac problems. Measurements were carried out twice in each patient, the first early in dialysis, the second toward the end of a dialysis session where fluid removal took place. The values for EVLW were 260+/-49 ml early in dialysis and 230+/-48 ml late in dialysis. This fall of 30+/-45 ml was statistically significant (p = 0.011). EVLW normalized to body weight was 3.29+/-1.0 ml/kg early and 3.02+/-1.04 ml/kg late in dialysis, a nonsignificant difference (p - 0.073). The normalized EVLW values are almost identical to those obtained in animals (3.1+/-1.4 ml/kg) by Krivitski et al. (see above). We conclude that this new technique can conveniently and noninvasively give an estimate of EVLW in hemodialysis patients. The clinical value of this measurement has now to be determined.     

Anesthesia with etomidate and remifentanil for cesarean section in a patient with severe peripartum cardiomyopathy--a case report

Patients with peripartum cardiomyopathy may require analgesia/anesthesia for delivery or cesarean section. Many different methods of anesthesia has been used for this purpose. Remifentanil was used safely in peripartum cardiomyopathic patients, but there is not any report about etomidate usage in such patients. We report on a 19 years old patient, at 32 weeks of gestation, with severe peripartum cardiomyopathy, in uncompensated heart failure and pulmonary edema. She was scheduled for emergency cesarean section becaue of threatening mother's life and fetal distress. General anesthesia was induced with etomidate and maintained with remifentanil infusion safely, without any adverse outcome on mother or newborn.     

Central,peripheral, and other blood volume changes during hemodialysis

Volume overload is a factor in development of hypertension in hemodialysis patients. Fluid removal by hemodialysis (HD), however, may cause intradialytic hypotension and associated symptoms. A better understanding of the relationships between blood pressure volume status and the pathophysiology of fluid removal during HD are, therefore, necessary to control blood pressure and to eliminate intradialytic hypotension. The objectives of the study were to determine the amount and direction of change of body fluid compartments after ultrafiltration (UF) and to determine whether any correlations exist between mean arterial pressure (MAP), change in circulating blood volume (deltaBV), total body water (TBW), central blood volume (which constitutes the volume of blood in the lungs, heart, and great vessels [CBV]), and intracellular and extracellular fluid volumes (ICF, ECF). The study population included 20 patients on regular HD. Each individual had their CBV, cardiac output, and peripheral vascular resistance (PVR) measured by means of saline dilution technique and deltaBV monitored by an online hematocrit sensor (Crit Line). MAP was calculated from measured blood pressure and ICF and ECF were measured using bioelectric impedance analysis techniques. Measurements were obtained before and after maximum UF measured by deltaBV (reduction of 6-10% by Crit Line). Ten healthy controls also had ECF and ICF values measured by bioelectric impedance analysis. Before HD, MAP correlated with TBW (r = 0.473, p = 0.035) and CBV (r = 0.419, p = 0.066), suggesting that hypertension here may be due to volume overload. Patients were ECF expanded before HD with an ECF:ICF ratio of 0.96, which was significantly higher than the control ratio of 0.74 (p < 0.0001). During UF, fluid was removed from both ECF and ICF, but more from the ECF volume ratio 0.92 post UF, a significant reduction (p < 0.0001). After UF, MAP no longer correlated with TBW or CBV but correlated with peripheral vascular resistance (r = 0.4575, p = 0.043). After UF, deltaBV correlated inversely with PVR (r = -0.50, p = 0.024). Despite the fall in deltaBV (7.11+/-2.49%) with UF, CBV was maintained. CBV were 0.899 L and 0.967 L pre and post UF, respectively. These data suggest that in hemodialysis patients, predialysis volume status influences predialysis blood pressure. UF causes BV to fall, but CBV is preferentially conserved by increasing PVR, which also maintains blood pressure. Failure of a PVR response likely leads to intradialytic hypotension.     

The protective activity of nanomicelle curcumin in bisphenol A‐induced cardiotoxicity following subacute exposure in rats

Bisphenol A (BPA), an estrogenic compound, is used in manufacture of polycarbonate plastics and epoxy resins. Curcumin, the active ingredient of turmeric, is a potent protective compound against cardiac diseases. In this study the protective effect of nanomicelle curcumin on BPA‐induced subchronic cardiotoxicity in rats was evaluated. Rats were divided into 6 groups including control, nanomicelle curcumin (50 mg/kg, gavage), BPA (50 mg/kg, gavage), nanomicelle curcumin (10, 25, and 50 mg/kg) plus BPA. The treatments were continued for 4 weeks. Results revealed that BPA significantly induced histophatological injuries including focal lymphatic inflammation, nuclear degenerative changes and cytoplasmic vacuolation, increased body weight, systolic and diastolic blood pressures, malondialdehyde and Creatine phosphokinase‐MB level and decreased glutathione content in comparison with control group. In addition, in electrocardiographic graph, RR, QT, and PQ intervals were increased by BPA. Western blot analysis showed that BPA up‐regulated phosphorylated p38 (p38‐mitogen‐activated protein kinase) and JNK (c‐jun NH₂ terminal kinases), while down‐regulated phosphorylated AKT (Protein Kinase B) and ERK1/2 (extracellular signal‐regulated protein kinases 1 and 2). However, nanomicelle curcumin (50 mg/kg) significantly improved these toxic effects of BPA in rat heart tissue. The results provide evidence that nanomicelle curcumin showed preventive effects on subchronic exposure to BPA induced toxicity in the heart tissue in rats.