Mahmood Ebrahimi

Hemodynamic Changes After Low-Dosage Hydrocortisone Administration in Vasopressor-Treated Preterm and Term Neonates

OBJECTIVE. We sought to investigate whether the increase in blood pressure and decrease in vasopressor support after hydrocortisone administration are associated with changes in systemic hemodynamics in neonates who receive high-dosage dopamine to maintain blood pressure at the lowest acceptable levels. METHODS. In this prospective, observational study, preterm and term neonates who required dopamine ≥15 μg/kg per minute to maintain minimum acceptable blood pressure received intravenous hydrocortisone 2 mg/kg followed by up to 4 doses of 1 mg/kg every 12 hours. Fifteen preterm and 5 term neonates without a patent ductus arteriosus composed the study population. Echocardiograms and vascular Doppler studies were performed immediately before the first dose of hydrocortisone and at 1, 2, 6 to 12, 24, and 48 hours thereafter. RESULTS. In the 15 preterm infants, during the first 12 hours of hydrocortisone treatment, the 28% increase in blood pressure paralleled that in the systemic vascular resistance without changes in stroke volume or cardiac output, whereas dopamine dosage decreased. By 24 hours, the dosage of dopamine continued to decrease, whereas stroke volume increased without additional changes in systemic vascular resistance. By 48 hours, dopamine dosage decreased by 72%; blood pressure and stroke volume increased by 31% and 33%, respectively; and systemic vascular resistance and cardiac output tended to be higher (14% and 21%, respectively) compared with baseline. Contractility, global myocardial function, and Doppler indices of blood flow in the middle cerebral and renal artery remained normal and unchanged. The findings in the 5 term infants showed a similar pattern for changes in cardiac function, systemic hemodynamics, and organ blood flow after hydrocortisone administration. CONCLUSIONS. In preterm and term neonates who require high-dosage dopamine to maintain blood pressure at the lowest acceptable levels, hydrocortisone improves blood pressure without compromising cardiac function, systemic perfusion, or cerebral and renal blood flow.

Pulsed Doppler Measurement of Left Ventricular Output as Early Predictor of Symptomatic Patent Ductus arteriosus in Very Preterm Infants

High left ventricular output (LVO) values are associated with symptomatic left-to-right ductal shunting in preterm infants. However, LVO data prior to the occurrence of symptomatic patent ductus arteriosus (SPDA) are lacking. To determine whether serial measurements could predict a SPDA, we measured LVO from day 1 until day 10 with pulsed Doppler echocardiography in 25 preterm infants with birth weights of less than 1,250 g and hematocrits of more than 0.40. Eleven infants never developed patent ductus arteriosus symptoms and had LVO values within the normal range (190-310 ml/min/kg) with only minimal daily variations. The remaining 14 infants developed SPDA which required treatment with indomethacin, ductal ligation, or fluid restriction on days 2-5. From day 1 until day 5 their mean LVO values were significantly higher compared to the group without left-to-right ductal shunt and this increase was secondary to higher stroke volume values. An increase in LVO of more than 60 ml/min/kg consistently preceded SPDA by at least 24 h. Serial measurements of LVO using a single-pulsed Doppler approach can be used for early prediction of SPDA.

The mechanical PR interval in fetuses of women with intrahepatic cholestasis of pregnancy

OBJECTIVE The purpose of this study was to evaluate the fetal mechanical PR interval in intrahepatic cholestasis of pregnancy (ICP). STUDY DESIGN Fetal echocardiography was performed for women with ICP and control subjects. Clinical characteristics, total bile acids, and liver profile tests were compared between groups. RESULTS Fourteen women with ICP and 7 control subjects were enrolled. Total bile acids (28.3 vs 6.2 μmol/L; P < .001), aspartate aminotransferase (53 vs 23 IU/L; P = .002), alanine aminotransferase (63 vs 19 IU/L; P = .002), and the PR interval (124 vs 110 msec; P = .006) were significantly higher in fetuses with ICP than in control fetuses. On multivariable linear regression analysis, only the presence of ICP was associated significantly with an increase in the PR interval (95% confidence interval, 4-24 msec; P = .01). CONCLUSION The fetal cardiac conduction system is altered in ICP. Further investigation is needed to determine whether fetal echocardiography can help to predict which fetuses are at risk for death that is associated with ICP.

A rare presentation of Pompe disease with massive hypertrophic cardiomyopathy at birth.

Abstract We report a term infant with Pompe disease presenting in the immediate newborn period. The infant was born at 40 weeks gestation, weighing 3600 g to a 32 year-old black female. Infant presented at delivery with massive hypertrophic cardiomyopathy and pulmonary hypertension. Diagnosis was confirmed by low α-glucosidase activity. The histopathology and electron microscopic findings were consistent with Pompe disease. This is the second reported case of Pompe disease presenting at delivery.

Paracetamol-induced ductal closure in a 5-month-old infant.

Recently, we cared for a 5-month-old baby boy born at 28 weeks gestation with a 1.9-mm patent ductus arteriosus (Fig 1). The parents were counselled regarding the plan for percutaneous device closure and asked to return 2 weeks later. Surprisingly, on repeat echocardiogram, the ductus arteriosus had closed. As spontaneous ductal closure is unusual past the newborn period, we questioned the parents about the events in the preceding 2 weeks. The parents reported administering paracetamol 12 mg/kg/dose twice daily for 4 days because of fussiness and nasal congestion. In premature infants during the newborn period, indomethacin or ibuprofen are first-line agents utilised for ductal closure. In patients with contraindications to non-steroidal anti-inflammatory drugs, paracetamol at 15 mg/kg/dose every 6 hours for 48 hours has been used effectively as a second-line agent. Previous authors have suggested that paracetamol works by acting at the peroxidase segment of prostaglandin synthetase and inhibits activity. To the best of our knowledge, our case is the first reported case of ductal closure associated with paracetamol outside of the newborn period. Further studies are needed to elucidate the role of paracetamol for ductal closure beyond the neonatal period.

69 BLOOD PRESSURE IN PRETERM NEONATES WITH A BIRTH WEIGHT OF 500 TO 1,250 GRAMS DURING THE FIRST WEEK OF LIFE: NORMATIVE VALUES, USE OF PRESSORS, AND STEROIDS.

Background Normal values of blood pressure are well established for healthy term newborn infants. In these infants, blood pressure increases rapidly during the first week and then gradually until 6 weeks of life. In contrast, most very low birth weight infants are not “healthy” and the normative value of blood pressure in these infants remains controversial. Methods Four hundred fifteen preterm infants with birth weights of 500 to 1,250 g were born at LAC+USC Medical Center between 1995 and 2005. Of these, 36 infants were excluded due to severe malformation or death during first week and the remaining 379 infants were entered in the study. Mean arterial pressure (MAP) was measured through an indwelling umbilical arterial catheter or peripheral arterial line. MAP values from each day were entered prospectively into the database. Lower limit of acceptable MAP was arbitrarily set at a value of gestational age (GA) plus 3 mm Hg at birth and appropriately adjusted for postnatal age. MAP lower than this limit triggered use of pressors and, if nonresponsive, addition of steroids. Results Conclusions Initial MAP among the extremely low birth weights is similar to those observed in infants > 1,000 g. MAP increased with increasing birth weight and advancing postnatal age in all weight groups. MAP observed in infants receiving pressors was similar to that seen in stable infants, who did not receive pressors. Our goal of maintaining MAP equal to GA +3 appears to be a reasonable target. Short- and long-term outcomes of these infants are in progress. Our data from a large number of preterm infants provide a basis for acceptable MAP values during the first week of life.

256 HEMODYNAMIC CHANGES IN RESPONSE TO HYDROCORTISONE IN PRESSOR-TREATED NEONATES WITH COMPENSATED SHOCK

Background In compensated shock, blood flow (BF) to non-vital organs (kidneys, intestine, etc) is decreased to ensure normal blood pressure (BP) and BF to vital organs. Neonates requiring high doses of dopamine (DA) to maintain BP in the normal range may still be in compensated shock with ongoing non-vital organ hypoperfusion. Since low-dose hydrocortisone (HC) rapidly improves BP and decreases the need for pressor support, we wished to examine whether the HC-induced improvement in BP was associated with improved cardiac output (CO) and non-vital organ BF i.e. with resolution of both uncompensated (hypotension) and compensated (decreased non-vital organ perfusion) shock. Objective To examine the changes in CO and vital and non-vital organ BF following HC treatment in preterm and term neonates receiving high-dose DA (± [DOB]) to maintain BP in the normal range. Methods Neonates were eligible for enrollment if they required DA ≥15 mcg/kg/min (± DOB). Upon enrollment, patients received 2 mg/kg of HC IV x1 followed by 1 mg/kg of HC q12 hr for 4 additional doses if remained hypotensive or required DA ≥8 mcg/kg/min to maintain BP in normal range. Echocardiograms and organ (middle cerebral artery [MCA] and renal artery [RA]) BF measurements were performed prior to the first dose of HC and at 1, 2, 6-12, 24 and 48 hrs thereafter. Cardiovascular (CV) parameters measured/calculated included CO, systemic vascular resistance (SVR), myocardial performance index (MPI) and MCA and RA pulsatility index (PI). The PI is inversely related to organ BF. BP, urine output (UV), blood gasses and dose of pressors were monitored and documented throughout the study. Results 12 patients have so far been enrolled without a patent ductus arteriosus (GA= 31.1±5.9 weeks; postnatal age= 16.9 ±15.2 days; birth weight= 1750±1086g). HC trended to increase BP, CO and SVR. Dose of DA was significantly decreased by 6-12 hours in all patients (p = 0.012). MCA PI remained unchanged while there was a trend for RA PI to decrease with the improvement in the CV status. UV increased and metabolic acidosis improved during the study. Conclusions Maintenance of “normal” BP on medium-to-high-dose pressor/inotrope support alone may not ensure normal non-vital organ BF. HC may increase BP by increasing both CO and SVR and thus result in complete resolution of shock.

Is There a Link between the Development of Systemic to Pulmonary Collaterals and Stage III or Greater Retinopathy of Prematurity in Very Low Birth Weight Infants? A Prospective Evaluation

Is There a Link between the Development of Systemic to Pulmonary Collaterals and Stage III or Greater Retinopathy of Prematurity in Very Low Birth Weight Infants? A Prospective Evaluation

Comparison of Saline Contrast and Color Doppler Echocardiography in the Detection of Right to Left Atrial Shunt in Newborn Infants

Comparison of Saline Contrast and Color Doppler Echocardiography in the Detection of Right to Left Atrial Shunt in Newborn Infants

Persistent Right Ventricular Sinusoids And Coronary Artery To Right Ventricle Communications (PRVS) Associated With Severe Neonatal Pulmonary Hypertension 78

Persistent Right Ventricular Sinusoids And Coronary Artery To Right Ventricle Communications (PRVS) Associated With Severe Neonatal Pulmonary Hypertension 78