Feizal Waffarn - Academia.edu (original) (raw)
Papers by Feizal Waffarn
Pediatric Research, 1994
IL-1 receptor antagonist (IGlra) is a cytokine that blocks the effects of I G 1 by binding to I G... more IL-1 receptor antagonist (IGlra) is a cytokine that blocks the effects of I G 1 by binding to I G 1 receptors without inducing signal transduction. Amniotic fluid contains high concentrations of IGlra. The purpose of this study was I) to analyze whether factors related to the mother or the fetus influence amniotic fluid I G l r a concentration, and 2) to study whether the fetus is a source of IGlra. Two hundred two specimens of amniotic fluid, as well as 21 urine samples from newborn infants, were analyzed. Women carrying a female fetus had a higher concentration of amniotic fluid I G l r a than those carrying a male fetus (female 136.4 f 6.1 pg/L, n = 83; male 74.7
Journal of Pediatric Surgery, 1998
Purpose: The authors reviewed their experience in the management of CDH after the introduction of... more Purpose: The authors reviewed their experience in the management of CDH after the introduction of early highfrequency oscillatory ventilation (HFOV) during the preoperative stabilization period and delayed CDH repair. Methods: This is a retrospective analysis of 24 consecutive infants with CDH treated at University of California, Irvine Medical Center (UCIMC) during a 36-month period from January 1993 to December 1996.
Acta Paediatrica, 1995
The causes of variable responsiveness to inhaled nitric oxide (NO) in Persistent Pulmonary Hypert... more The causes of variable responsiveness to inhaled nitric oxide (NO) in Persistent Pulmonary Hypertension of the Newborn (PPHN) are unknown. The changes in the severity of respiratory failure after the onset of inhaled NO (maximal dose 20 ppm) were studied in 13 consecutive neonates with severe PPHN. Response was defined as a sustained decrease of alveolar-arterial oxygen gradient (AaDO2) by > 20%, or a decrease in oxygenation index (OI) by > 40%. Six neonates had a rapid response within 30 min, three had an intermediate response within 8 h, and three had a delayed response within 12 h after the onset of NO. Three infants with birth asphyxia responded rapidly to inhaled NO. One infant with sepsis did not respond, and two with suspected sepsis had a delayed response. The infants with Meconium Aspiration Syndrome and idiopathic PPHN had a variable response time. Twelve neonates required 4 to 14 days of mechanical ventilation and survived. Infants with PPHN may benefit from a trial of inhaled NO therapy that exceeds 30 min. The variability of the response time to inhaled NO is likely to be multifactorial and dependent on the disease process associated with PPHN.
Acta Paediatrica, 1995
Interleukin-1 (IL-1) is a major mediator in infections and inflammation. Interleukin-1 receptor a... more Interleukin-1 (IL-1) is a major mediator in infections and inflammation. Interleukin-1 receptor antagonist (IL-1ra) opposes the actions of IL-1. IL-1ra is present in exceptionally high concentrations in third trimester amniotic fluid. We studied IL-1ra in amniotic fluid, fetal serum and newborn urine. The concentrations of IL-1ra in amniotic fluid at mid-trimester and at 25-41 gestational weeks were 6.6 +/- 0.5 ng/ml (n = 30) and 100 +/- 4 ng/ml (n = 202), respectively. At mid-trimester, amniotic fluid IL-1ra was not dependent on fetal gender, whereas during the third trimester IL-1ra was higher in female- than in male-bearing gestations. Urine of normal term newborns during the first day of life contained a very high concentration of IL-1ra (125 +/- 16 ng/ml, n = 50). Urinary concentration in female newborns was significantly higher than that in male newborns (202 +/- 19 ng/ml, n = 25 versus 49 +/- 14 ng/ml, n = 25). IL-1ra concentration in fetal serum at 22-36 gestational weeks was 0.50 +/- 0.07 ng/ml (n = 31) and at term 1.5 +/- 0.3 ng/ml (n = 17). Serum concentrations were not gender-dependent. The gender differences in IL-1ra concentrations may in part explain the lower susceptibility of female fetuses to infection.
American Journal of Obstetrics and Gynecology, 2012
The hypothalamic-pituitary-adrenocortical (HPA) axis is a major neuro-endocrine pathway that modu... more The hypothalamic-pituitary-adrenocortical (HPA) axis is a major neuro-endocrine pathway that modulates the stress response. The glucocorticoid, cortisol is the principal end product of the HPA axis in humans, and plays a fundamental role in maintaining homeostasis and in fetal maturation and development. Antenatal administration of synthetic glucocorticoids (GCs) accelerates fetal lung maturation and has significantly decreased neonatal mortality and morbidity in infants born before 34 weeks of gestation. Exposure to excess levels of endogenous GCs and exogenous GCs (betamethasone and dexamethasone) has been shown to alter the normal development trajectory. The development and regulation of the fetal HPA axis is discussed and the experimental animal evidence presented suggests long-term adverse consequences of altered HPA function. The clinical data in infants exposed to GCs also suggests altered HPA axis function over the short term. The longer-term consequences of antenatal GC exposure on HPA axis function and subtler neurodevelopmental outcomes including adaptation to stress, cognition, behavior, and the cardiovascular and immune responses are poorly understood. Emerging clinical strategies and interventions may help in the selection of mothers at risk for preterm delivery who would benefit from existing or future formulations of antenatal GCs with a reduction in the associated risk to the fetus and newborn. Detailed longitudinal long-term follow up of those infants exposed to synthetic GCs are needed.
ABSTRACT: The objective of this study was to determine the consequences for HPA axis functioning ... more ABSTRACT: The objective of this study was to determine the consequences for HPA axis functioning among healthy full-term newborns of prenatal treatment with the synthetic glucocorticoid (GC), betamethasone, which is the routine treatment for threatened preterm delivery. Ninety full-term infants were recruited into two study groups (30 betamethasone treated; 60 comparison group matched for GA at birth and sex). The cortisol and behavioral response to the painful stress of a heel-stick blood draw was assessed 24 hr after birth. Full-term infants exposed to prenatal betamethasone displayed a larger cortisol response to the heel-stick procedure, despite no differences in baseline levels. Further, within the recommended window of betamethasone administration (24–34 gestational weeks), infants exposed to betamethasone earlier in gestation displayed the largest cortisol response to the heel-stick. These data add to accumulating evidence that prenatal exposure to elevated GCs programs the d...
The applicability of using an inert tracer gas to measure intestinal blood flow is investigated. ... more The applicability of using an inert tracer gas to measure intestinal blood flow is investigated. The results from studies carried out to demonstrate that the pulmonary clearance of an inert noncombustible gas (helium) instilled into the colon changes predictably with colon blood flow (CBF) are presented. The results indicate that pulmonary clearance of the tracer gas follows expected changes in colon blood flow during hypoxia, hypovolemic hypotension,and vascular occlusion and correlates well with colon blood flow measured by radiolabeled microspheres
Journal of Perinatology
Pulmonary function measurements were studied on equivalent levels of positive end-expiratory pres... more Pulmonary function measurements were studied on equivalent levels of positive end-expiratory pressure (PEEP) and continuous negative pressure (CNP) while controlling for transpulmonary pressure (TPP). Four adult rabbits were anesthetized, instrumented, and ventilated with intermittent mandatory ventilation by using peak inspiratory pressure (PIP) of 16 cm H2O, PEEP 0 cm H2O, CNP 0 cm H2O, inspiratory time 0.3 seconds, rate 20/min, and fraction of inspired oxygen of 0.3. Subsequently, equal amounts of PEEP and CNP were alternated for 15-minute ventilation periods. PIP was changed to approximate the TPP in each PEEP/CNP pair. There was a significant decrease in PCO2 and increase in pH, mechanical tidal volume, minute ventilation, functional residual capacity, and total dynamic compliance on CNP. These differences could not be explained by changes in TPP.
Clinical pharmacy
The pharmacokinetics of gentamicin in large-for-gestational-age (LGA) and appropriate-for-gestati... more The pharmacokinetics of gentamicin in large-for-gestational-age (LGA) and appropriate-for-gestational-age (AGA) newborn infants were compared in a prospective study. Serum gentamicin concentrations were drawn just before (trough) or after (peak) the third or fourth dose of gentamicin sulfate 2.5 mg/kg given as a 30-minute i.v. infusion every 12 hours to 11 LGA and 12 AGA infants. Peak (Cmax) and trough ( Cmin ) serum concentrations, elimination rate constants (k), volumes of distribution (V), and clearances (CL) were compared between the AGA and LGA groups and within the LGA group between obese (n = 6) and nonobese (n = 5) infants. The serum gentamicin concentrations achieved in the LGA infants were similar to those in the AGA infants, with Cmin values less than 2 micrograms/ml and Cmax values of 4-7 micrograms/ml. The mean pharmacokinetic variables determined were consistent with literature values reported for AGA infants. No significant differences in these variables were observed...
Journal of Biomedical Optics, 2005
Red blood cell ͑RBC͒ transfusion guidelines are designed to maintain adequate tissue oxygenation ... more Red blood cell ͑RBC͒ transfusion guidelines are designed to maintain adequate tissue oxygenation by increasing blood oxygencarrying capacity. However, since tissue oxygenation is not measured, RBC transfusion guidelines are mostly subjective. Clinical evidence of oxygen transport/consumption mismatches in infants is often unclear and confounded by multiple factors. Invasive hemoglobin measurements can contribute further to anemia if performed too frequently. Diffuse optical spectroscopy ͑DOS͒ is a noninvasive quantitative method to measure the tissue oxy, deoxy, and total hemoglobin concentrations ͑ctO 2 Hb, ctHb, ctTHb͒, as well as mixed arterial-venous tissue hemoglobin saturation ͑stO 2 ͒. Our objective is to determine if DOS can assess changes in tissue oxygenation in very low birth weight ͑VLBW͒ infants undergoing RBC transfusions. DOS measurements of ctO 2 Hb and ctHb are performed on 10 VLBW infants before and within 24 h after RBC transfusion. Seven nontransfused infants are studied to evaluate hemodynamic variations independent of RBC transfusion. Tissue near-infrared absorption and scattering values are measured using a four-wavelength ͑690, 750, 810, and 830 nm͒ frequency-domain tissue oximeter ͑OxiplexTS, ISS, Champaign, Illi-nois͒. In transfused subjects, DOS demonstrates significant increases in ctO 2 Hb ͑48± 13 versus 74± 20 M,p Ͻ 0.002͒, ctTHb ͑87± 17 versus 107± 24 M,p = 0.004͒, and stO 2 ͑54± 8 versus 68±6% ,p Ͻ 0.004͒ post-transfusion. DOS measurements correlate with mean hemoglobin increases for all infants ͑r = 0.83, p Ͻ 0.0001͒. No significant DOS changes occurred in the nontransfused group. Calculations of the differential path length for these transfused subjects show high variability ͑ϳ20% ͒. DOS may serve as a noninvasive bedside tool to assess tissue oxygenation in infants and provide a functionally based transfusion trigger.
Pediatric Surgery …, 2007
In Japan, mortality due to intestinal perforation has been increasing for the last 15 years, as t... more In Japan, mortality due to intestinal perforation has been increasing for the last 15 years, as the survival rate of extremely-low-birth-weight neonates (ELBWs) has been increasing. In our NICU, although the incidence of necrotizing enterocolitis has been ...
American Journal of Obstetrics and Gynecology
Background-The production of variation in adipose tissue accretion represents a key fetal adaptat... more Background-The production of variation in adipose tissue accretion represents a key fetal adaptation to energy substrate availability during gestation. Because umbilical venous blood transports nutrient substrate from the maternal to the fetal compartment, and the fetal liver is the primary organ where nutrient inter-conversion occurs, it has been proposed that variations in the relative distribution of umbilical venous blood flow shunting either through ductus venosus or perfusing the fetal liver represents a mechanism underlying this adaptation.
American Journal of Obstetrics and Gynecology
To evaluate the incidence of preterm birth (PTB) amongst patients with amniotic fluid sludge acco... more To evaluate the incidence of preterm birth (PTB) amongst patients with amniotic fluid sludge according to whether or not they had been treated with antibiotics following initial diagnosis. Additional maternal and neonatal outcomes were evaluated according to cohort. STUDY DESIGN: We performed a retrospective cohort study of all patients diagnosed with amniotic fluid sludge in the outpatient ultrasound suite at a single academic center between 2010-2017. Patients were separated into cohorts based on whether or not they had been treated with antibiotics at the time of diagnosis. Patients with multiple gestation, fetal anomalies, pre-viable preterm rupture of membranes prior to initial diagnosis of amniotic fluid sludge, active preterm labor, placenta previa and/or suspected accreta were excluded. Primary outcome of preterm birth was compared by univariate analysis as well as regression analysis, so as to control for potential co-linear and/or confounding variables. Additional outcomes were compared by univariate analysis. RESULTS: A total of 181 patients were identified and considered for inclusion. 97 met inclusion criteria. Of those, 51 were treated with PO antibiotics (46 with PO azithromycin and 5 with PO moxifloxacin) and 46 were not treated. The incidence of PTB < 37 wks was 49.4 % (48/97) and PTB < 28 wks was 22.7% (22/97). There was no significant difference in incidence of preterm birth between the two cohorts, either < 37 weeks (p¼0.47) or < 28 weeks (p¼0.83). After adjusting for race, BMI, tobacco use, cervical length and PTB history, the incidence of PTB with antibiotic treatment remained insignificant (OR 1.3, 0.77-1.9). No differences were seen in the incidence of PPROM (p¼0.94) or mean latency from diagnosis (p¼0.95). Neonatal outcomes including birthweight (p¼0.77), sepsis (p¼0.53), IVH (p¼0.95), LOS (p¼0.46), and NICU admission (p¼0.08) were not different between cohorts. There was no difference in the incidence of either clinical or pathologic chorioamnionitis between cohorts (p¼0.92 and 0.14, respectively). CONCLUSION: Antibiotic treatment administered after the initial diagnosis of amniotic fluid sludge is not associated with a reduction in the rates of premature birth when compared to expectant management. Likewise, treatment of amniotic fluid sludge was not associated with improvement in evaluated obstetric, pathologic, or neonatal variables compared to expectant management. These findings demonstrate the need for a prospective trial.
Obstet Gynecol Surv, 1983
A case of prolonged fetal exposure to hyperbilirubinemia occurred in a mother with end-stage live... more A case of prolonged fetal exposure to hyperbilirubinemia occurred in a mother with end-stage liver disease during the second and third trimester of pregnancy. At birth, the infant had elevated levels of both conjugated and unconjugated serum bilirubin that required multiple-exchange transfusions during the first three days of life. The infant exhibited abnormal neurologic findings at birth that resolved during the neonatal period. The results of subsequent developmental and neurologic evaluation were normal at 14 months of follow-up. Prolonged fetal exposure to elevated serum bilirubin levels may not necessarily result in developmental or neurologic handicap.
Critical Care Medicine, Dec 1, 1979
The continuous recordings of arterial oxygen saturation (SaO2) and beat-to-beat heart rate before... more The continuous recordings of arterial oxygen saturation (SaO2) and beat-to-beat heart rate before, during, and after tracheobronchial suctioning were studied in eight preterm infants with severe RDS receiving mechanical ventilation. Two suctioning procedures were alternatively performed in each infant; In procedure A, disconnection of the ventilator and preoxygenation preceded suctioning; in procedure B, a special suction adaptor was used without ventilatory interruption or preoxygenation; 128 suctionings were performed with each procedure and the changes in heart rate (HR) and SaO2 during suctioning were compared. Although in both procedures, HR and SaO2 decreased during suctioning, the degree of bradycardia and arterial blood oxygen desaturation were significantly smaller in magnitude and shorter in duration during procedure B. These data indicate advantages of the suction adaptor in minimizing bradycardia and hypoxia from airway suction.
Ultrasound in Obstetrics & Gynecology, 2012
positive likelihood ratio was fetal AC above the 90 th percentile at 28 weeks (LR + 6.56 for birt... more positive likelihood ratio was fetal AC above the 90 th percentile at 28 weeks (LR + 6.56 for birthweight above 4500 g, LR − 0.37). Conclusions: For women who are overweight and obese during pregnancy, EFW above the 90 th percentile in the third trimester is strongly and significantly associated with birthweight above 4000 g and 4500 g and a woman's chance of elective caesarean section.
Journal of perinatology : official journal of the California Perinatal Association
A 28-week preterm infant had a percutaneous silicone-rubber central venous catheter placed for pa... more A 28-week preterm infant had a percutaneous silicone-rubber central venous catheter placed for parenteral nutritional support. The catheter was later found to have fractured, and a 5.5 cm piece of catheter was lodged in the patient's right atrium. It was retrieved percutaneously by fluoroscopically guided cardiac catheterization without complications. Fracture and embolization of a catheter is a rare but serious complication of central venous catheters, and we report our experience as the only known case of a silicone-rubber catheter fracture and embolization in a premature infant, in which the catheter fragment was retrieved via a percutaneous endovascular approach.
Journal of cardiology, 1988
To study the effect of acute hematocrit changes on the central circulation of human neonates, pul... more To study the effect of acute hematocrit changes on the central circulation of human neonates, pulsed Doppler echocardiography was performed to evaluate flow velocities in the main pulmonary artery (PA) and the ascending aorta (Ao) five and seven hours of age in 16 polycythemic neonates (mean hematocrit of 68.1%), and in 12 normal neonates (mean hematocrit of 57.1%). All the polycythemic neonates were asymptomatic and underwent isovolumic partial exchange transfusion between five and seven hours of age to lower their mean hematocrit to 51.3%. Flow velocity integral per min (FVI/min) (cm/min), acceleration time (AT) (ms), and the ratio of pre-ejection period to ejection time (PEP/ET) were measured on the PA and Ao flow velocity tracings. Despite the significant differences in hematocrit, no significant difference was observed in any of their flow velocity indices at five hours age between the normal and polycythemic neonates. All flow velocity indices remained unchanged between five a...
Journal of perinatology : official journal of the California Perinatal Association, 1989
We reviewed the clinical courses of 12 prematurely born newborns who were placed in continuous ne... more We reviewed the clinical courses of 12 prematurely born newborns who were placed in continuous negative pressure (CNP) in an Isolette negative pressure ventilator for refractory hypoxemia while receiving intermittent positive pressure mandatory ventilation. All patients had severe lung disease as documented by an increased oxygenation index and bilateral pulmonary interstitial emphysema on x-ray examination. Patients were separated into two groups--survivors and nonsurvivors, with six patients in each group. Initiation of CNP resulted in a significant initial improvement in oxygenation in both groups seen as a 52% decrease in the oxygenation index in survivors and a 57% decrease in the oxygenation index in nonsurvivors (P less than .05). The survivors characterized themselves by showing a further sustained improvement in the oxygenation index--31.4 +/- 9.1 to 6.9 +/- 5.0 (P less than .01)--and a significant decrease in the mean airway pressure--11.6 +/- 4.6 cm H2O to 5.0 +/- 1.9 cm ...
Pediatric Research, 1994
IL-1 receptor antagonist (IGlra) is a cytokine that blocks the effects of I G 1 by binding to I G... more IL-1 receptor antagonist (IGlra) is a cytokine that blocks the effects of I G 1 by binding to I G 1 receptors without inducing signal transduction. Amniotic fluid contains high concentrations of IGlra. The purpose of this study was I) to analyze whether factors related to the mother or the fetus influence amniotic fluid I G l r a concentration, and 2) to study whether the fetus is a source of IGlra. Two hundred two specimens of amniotic fluid, as well as 21 urine samples from newborn infants, were analyzed. Women carrying a female fetus had a higher concentration of amniotic fluid I G l r a than those carrying a male fetus (female 136.4 f 6.1 pg/L, n = 83; male 74.7
Journal of Pediatric Surgery, 1998
Purpose: The authors reviewed their experience in the management of CDH after the introduction of... more Purpose: The authors reviewed their experience in the management of CDH after the introduction of early highfrequency oscillatory ventilation (HFOV) during the preoperative stabilization period and delayed CDH repair. Methods: This is a retrospective analysis of 24 consecutive infants with CDH treated at University of California, Irvine Medical Center (UCIMC) during a 36-month period from January 1993 to December 1996.
Acta Paediatrica, 1995
The causes of variable responsiveness to inhaled nitric oxide (NO) in Persistent Pulmonary Hypert... more The causes of variable responsiveness to inhaled nitric oxide (NO) in Persistent Pulmonary Hypertension of the Newborn (PPHN) are unknown. The changes in the severity of respiratory failure after the onset of inhaled NO (maximal dose 20 ppm) were studied in 13 consecutive neonates with severe PPHN. Response was defined as a sustained decrease of alveolar-arterial oxygen gradient (AaDO2) by > 20%, or a decrease in oxygenation index (OI) by > 40%. Six neonates had a rapid response within 30 min, three had an intermediate response within 8 h, and three had a delayed response within 12 h after the onset of NO. Three infants with birth asphyxia responded rapidly to inhaled NO. One infant with sepsis did not respond, and two with suspected sepsis had a delayed response. The infants with Meconium Aspiration Syndrome and idiopathic PPHN had a variable response time. Twelve neonates required 4 to 14 days of mechanical ventilation and survived. Infants with PPHN may benefit from a trial of inhaled NO therapy that exceeds 30 min. The variability of the response time to inhaled NO is likely to be multifactorial and dependent on the disease process associated with PPHN.
Acta Paediatrica, 1995
Interleukin-1 (IL-1) is a major mediator in infections and inflammation. Interleukin-1 receptor a... more Interleukin-1 (IL-1) is a major mediator in infections and inflammation. Interleukin-1 receptor antagonist (IL-1ra) opposes the actions of IL-1. IL-1ra is present in exceptionally high concentrations in third trimester amniotic fluid. We studied IL-1ra in amniotic fluid, fetal serum and newborn urine. The concentrations of IL-1ra in amniotic fluid at mid-trimester and at 25-41 gestational weeks were 6.6 +/- 0.5 ng/ml (n = 30) and 100 +/- 4 ng/ml (n = 202), respectively. At mid-trimester, amniotic fluid IL-1ra was not dependent on fetal gender, whereas during the third trimester IL-1ra was higher in female- than in male-bearing gestations. Urine of normal term newborns during the first day of life contained a very high concentration of IL-1ra (125 +/- 16 ng/ml, n = 50). Urinary concentration in female newborns was significantly higher than that in male newborns (202 +/- 19 ng/ml, n = 25 versus 49 +/- 14 ng/ml, n = 25). IL-1ra concentration in fetal serum at 22-36 gestational weeks was 0.50 +/- 0.07 ng/ml (n = 31) and at term 1.5 +/- 0.3 ng/ml (n = 17). Serum concentrations were not gender-dependent. The gender differences in IL-1ra concentrations may in part explain the lower susceptibility of female fetuses to infection.
American Journal of Obstetrics and Gynecology, 2012
The hypothalamic-pituitary-adrenocortical (HPA) axis is a major neuro-endocrine pathway that modu... more The hypothalamic-pituitary-adrenocortical (HPA) axis is a major neuro-endocrine pathway that modulates the stress response. The glucocorticoid, cortisol is the principal end product of the HPA axis in humans, and plays a fundamental role in maintaining homeostasis and in fetal maturation and development. Antenatal administration of synthetic glucocorticoids (GCs) accelerates fetal lung maturation and has significantly decreased neonatal mortality and morbidity in infants born before 34 weeks of gestation. Exposure to excess levels of endogenous GCs and exogenous GCs (betamethasone and dexamethasone) has been shown to alter the normal development trajectory. The development and regulation of the fetal HPA axis is discussed and the experimental animal evidence presented suggests long-term adverse consequences of altered HPA function. The clinical data in infants exposed to GCs also suggests altered HPA axis function over the short term. The longer-term consequences of antenatal GC exposure on HPA axis function and subtler neurodevelopmental outcomes including adaptation to stress, cognition, behavior, and the cardiovascular and immune responses are poorly understood. Emerging clinical strategies and interventions may help in the selection of mothers at risk for preterm delivery who would benefit from existing or future formulations of antenatal GCs with a reduction in the associated risk to the fetus and newborn. Detailed longitudinal long-term follow up of those infants exposed to synthetic GCs are needed.
ABSTRACT: The objective of this study was to determine the consequences for HPA axis functioning ... more ABSTRACT: The objective of this study was to determine the consequences for HPA axis functioning among healthy full-term newborns of prenatal treatment with the synthetic glucocorticoid (GC), betamethasone, which is the routine treatment for threatened preterm delivery. Ninety full-term infants were recruited into two study groups (30 betamethasone treated; 60 comparison group matched for GA at birth and sex). The cortisol and behavioral response to the painful stress of a heel-stick blood draw was assessed 24 hr after birth. Full-term infants exposed to prenatal betamethasone displayed a larger cortisol response to the heel-stick procedure, despite no differences in baseline levels. Further, within the recommended window of betamethasone administration (24–34 gestational weeks), infants exposed to betamethasone earlier in gestation displayed the largest cortisol response to the heel-stick. These data add to accumulating evidence that prenatal exposure to elevated GCs programs the d...
The applicability of using an inert tracer gas to measure intestinal blood flow is investigated. ... more The applicability of using an inert tracer gas to measure intestinal blood flow is investigated. The results from studies carried out to demonstrate that the pulmonary clearance of an inert noncombustible gas (helium) instilled into the colon changes predictably with colon blood flow (CBF) are presented. The results indicate that pulmonary clearance of the tracer gas follows expected changes in colon blood flow during hypoxia, hypovolemic hypotension,and vascular occlusion and correlates well with colon blood flow measured by radiolabeled microspheres
Journal of Perinatology
Pulmonary function measurements were studied on equivalent levels of positive end-expiratory pres... more Pulmonary function measurements were studied on equivalent levels of positive end-expiratory pressure (PEEP) and continuous negative pressure (CNP) while controlling for transpulmonary pressure (TPP). Four adult rabbits were anesthetized, instrumented, and ventilated with intermittent mandatory ventilation by using peak inspiratory pressure (PIP) of 16 cm H2O, PEEP 0 cm H2O, CNP 0 cm H2O, inspiratory time 0.3 seconds, rate 20/min, and fraction of inspired oxygen of 0.3. Subsequently, equal amounts of PEEP and CNP were alternated for 15-minute ventilation periods. PIP was changed to approximate the TPP in each PEEP/CNP pair. There was a significant decrease in PCO2 and increase in pH, mechanical tidal volume, minute ventilation, functional residual capacity, and total dynamic compliance on CNP. These differences could not be explained by changes in TPP.
Clinical pharmacy
The pharmacokinetics of gentamicin in large-for-gestational-age (LGA) and appropriate-for-gestati... more The pharmacokinetics of gentamicin in large-for-gestational-age (LGA) and appropriate-for-gestational-age (AGA) newborn infants were compared in a prospective study. Serum gentamicin concentrations were drawn just before (trough) or after (peak) the third or fourth dose of gentamicin sulfate 2.5 mg/kg given as a 30-minute i.v. infusion every 12 hours to 11 LGA and 12 AGA infants. Peak (Cmax) and trough ( Cmin ) serum concentrations, elimination rate constants (k), volumes of distribution (V), and clearances (CL) were compared between the AGA and LGA groups and within the LGA group between obese (n = 6) and nonobese (n = 5) infants. The serum gentamicin concentrations achieved in the LGA infants were similar to those in the AGA infants, with Cmin values less than 2 micrograms/ml and Cmax values of 4-7 micrograms/ml. The mean pharmacokinetic variables determined were consistent with literature values reported for AGA infants. No significant differences in these variables were observed...
Journal of Biomedical Optics, 2005
Red blood cell ͑RBC͒ transfusion guidelines are designed to maintain adequate tissue oxygenation ... more Red blood cell ͑RBC͒ transfusion guidelines are designed to maintain adequate tissue oxygenation by increasing blood oxygencarrying capacity. However, since tissue oxygenation is not measured, RBC transfusion guidelines are mostly subjective. Clinical evidence of oxygen transport/consumption mismatches in infants is often unclear and confounded by multiple factors. Invasive hemoglobin measurements can contribute further to anemia if performed too frequently. Diffuse optical spectroscopy ͑DOS͒ is a noninvasive quantitative method to measure the tissue oxy, deoxy, and total hemoglobin concentrations ͑ctO 2 Hb, ctHb, ctTHb͒, as well as mixed arterial-venous tissue hemoglobin saturation ͑stO 2 ͒. Our objective is to determine if DOS can assess changes in tissue oxygenation in very low birth weight ͑VLBW͒ infants undergoing RBC transfusions. DOS measurements of ctO 2 Hb and ctHb are performed on 10 VLBW infants before and within 24 h after RBC transfusion. Seven nontransfused infants are studied to evaluate hemodynamic variations independent of RBC transfusion. Tissue near-infrared absorption and scattering values are measured using a four-wavelength ͑690, 750, 810, and 830 nm͒ frequency-domain tissue oximeter ͑OxiplexTS, ISS, Champaign, Illi-nois͒. In transfused subjects, DOS demonstrates significant increases in ctO 2 Hb ͑48± 13 versus 74± 20 M,p Ͻ 0.002͒, ctTHb ͑87± 17 versus 107± 24 M,p = 0.004͒, and stO 2 ͑54± 8 versus 68±6% ,p Ͻ 0.004͒ post-transfusion. DOS measurements correlate with mean hemoglobin increases for all infants ͑r = 0.83, p Ͻ 0.0001͒. No significant DOS changes occurred in the nontransfused group. Calculations of the differential path length for these transfused subjects show high variability ͑ϳ20% ͒. DOS may serve as a noninvasive bedside tool to assess tissue oxygenation in infants and provide a functionally based transfusion trigger.
Pediatric Surgery …, 2007
In Japan, mortality due to intestinal perforation has been increasing for the last 15 years, as t... more In Japan, mortality due to intestinal perforation has been increasing for the last 15 years, as the survival rate of extremely-low-birth-weight neonates (ELBWs) has been increasing. In our NICU, although the incidence of necrotizing enterocolitis has been ...
American Journal of Obstetrics and Gynecology
Background-The production of variation in adipose tissue accretion represents a key fetal adaptat... more Background-The production of variation in adipose tissue accretion represents a key fetal adaptation to energy substrate availability during gestation. Because umbilical venous blood transports nutrient substrate from the maternal to the fetal compartment, and the fetal liver is the primary organ where nutrient inter-conversion occurs, it has been proposed that variations in the relative distribution of umbilical venous blood flow shunting either through ductus venosus or perfusing the fetal liver represents a mechanism underlying this adaptation.
American Journal of Obstetrics and Gynecology
To evaluate the incidence of preterm birth (PTB) amongst patients with amniotic fluid sludge acco... more To evaluate the incidence of preterm birth (PTB) amongst patients with amniotic fluid sludge according to whether or not they had been treated with antibiotics following initial diagnosis. Additional maternal and neonatal outcomes were evaluated according to cohort. STUDY DESIGN: We performed a retrospective cohort study of all patients diagnosed with amniotic fluid sludge in the outpatient ultrasound suite at a single academic center between 2010-2017. Patients were separated into cohorts based on whether or not they had been treated with antibiotics at the time of diagnosis. Patients with multiple gestation, fetal anomalies, pre-viable preterm rupture of membranes prior to initial diagnosis of amniotic fluid sludge, active preterm labor, placenta previa and/or suspected accreta were excluded. Primary outcome of preterm birth was compared by univariate analysis as well as regression analysis, so as to control for potential co-linear and/or confounding variables. Additional outcomes were compared by univariate analysis. RESULTS: A total of 181 patients were identified and considered for inclusion. 97 met inclusion criteria. Of those, 51 were treated with PO antibiotics (46 with PO azithromycin and 5 with PO moxifloxacin) and 46 were not treated. The incidence of PTB < 37 wks was 49.4 % (48/97) and PTB < 28 wks was 22.7% (22/97). There was no significant difference in incidence of preterm birth between the two cohorts, either < 37 weeks (p¼0.47) or < 28 weeks (p¼0.83). After adjusting for race, BMI, tobacco use, cervical length and PTB history, the incidence of PTB with antibiotic treatment remained insignificant (OR 1.3, 0.77-1.9). No differences were seen in the incidence of PPROM (p¼0.94) or mean latency from diagnosis (p¼0.95). Neonatal outcomes including birthweight (p¼0.77), sepsis (p¼0.53), IVH (p¼0.95), LOS (p¼0.46), and NICU admission (p¼0.08) were not different between cohorts. There was no difference in the incidence of either clinical or pathologic chorioamnionitis between cohorts (p¼0.92 and 0.14, respectively). CONCLUSION: Antibiotic treatment administered after the initial diagnosis of amniotic fluid sludge is not associated with a reduction in the rates of premature birth when compared to expectant management. Likewise, treatment of amniotic fluid sludge was not associated with improvement in evaluated obstetric, pathologic, or neonatal variables compared to expectant management. These findings demonstrate the need for a prospective trial.
Obstet Gynecol Surv, 1983
A case of prolonged fetal exposure to hyperbilirubinemia occurred in a mother with end-stage live... more A case of prolonged fetal exposure to hyperbilirubinemia occurred in a mother with end-stage liver disease during the second and third trimester of pregnancy. At birth, the infant had elevated levels of both conjugated and unconjugated serum bilirubin that required multiple-exchange transfusions during the first three days of life. The infant exhibited abnormal neurologic findings at birth that resolved during the neonatal period. The results of subsequent developmental and neurologic evaluation were normal at 14 months of follow-up. Prolonged fetal exposure to elevated serum bilirubin levels may not necessarily result in developmental or neurologic handicap.
Critical Care Medicine, Dec 1, 1979
The continuous recordings of arterial oxygen saturation (SaO2) and beat-to-beat heart rate before... more The continuous recordings of arterial oxygen saturation (SaO2) and beat-to-beat heart rate before, during, and after tracheobronchial suctioning were studied in eight preterm infants with severe RDS receiving mechanical ventilation. Two suctioning procedures were alternatively performed in each infant; In procedure A, disconnection of the ventilator and preoxygenation preceded suctioning; in procedure B, a special suction adaptor was used without ventilatory interruption or preoxygenation; 128 suctionings were performed with each procedure and the changes in heart rate (HR) and SaO2 during suctioning were compared. Although in both procedures, HR and SaO2 decreased during suctioning, the degree of bradycardia and arterial blood oxygen desaturation were significantly smaller in magnitude and shorter in duration during procedure B. These data indicate advantages of the suction adaptor in minimizing bradycardia and hypoxia from airway suction.
Ultrasound in Obstetrics & Gynecology, 2012
positive likelihood ratio was fetal AC above the 90 th percentile at 28 weeks (LR + 6.56 for birt... more positive likelihood ratio was fetal AC above the 90 th percentile at 28 weeks (LR + 6.56 for birthweight above 4500 g, LR − 0.37). Conclusions: For women who are overweight and obese during pregnancy, EFW above the 90 th percentile in the third trimester is strongly and significantly associated with birthweight above 4000 g and 4500 g and a woman's chance of elective caesarean section.
Journal of perinatology : official journal of the California Perinatal Association
A 28-week preterm infant had a percutaneous silicone-rubber central venous catheter placed for pa... more A 28-week preterm infant had a percutaneous silicone-rubber central venous catheter placed for parenteral nutritional support. The catheter was later found to have fractured, and a 5.5 cm piece of catheter was lodged in the patient's right atrium. It was retrieved percutaneously by fluoroscopically guided cardiac catheterization without complications. Fracture and embolization of a catheter is a rare but serious complication of central venous catheters, and we report our experience as the only known case of a silicone-rubber catheter fracture and embolization in a premature infant, in which the catheter fragment was retrieved via a percutaneous endovascular approach.
Journal of cardiology, 1988
To study the effect of acute hematocrit changes on the central circulation of human neonates, pul... more To study the effect of acute hematocrit changes on the central circulation of human neonates, pulsed Doppler echocardiography was performed to evaluate flow velocities in the main pulmonary artery (PA) and the ascending aorta (Ao) five and seven hours of age in 16 polycythemic neonates (mean hematocrit of 68.1%), and in 12 normal neonates (mean hematocrit of 57.1%). All the polycythemic neonates were asymptomatic and underwent isovolumic partial exchange transfusion between five and seven hours of age to lower their mean hematocrit to 51.3%. Flow velocity integral per min (FVI/min) (cm/min), acceleration time (AT) (ms), and the ratio of pre-ejection period to ejection time (PEP/ET) were measured on the PA and Ao flow velocity tracings. Despite the significant differences in hematocrit, no significant difference was observed in any of their flow velocity indices at five hours age between the normal and polycythemic neonates. All flow velocity indices remained unchanged between five a...
Journal of perinatology : official journal of the California Perinatal Association, 1989
We reviewed the clinical courses of 12 prematurely born newborns who were placed in continuous ne... more We reviewed the clinical courses of 12 prematurely born newborns who were placed in continuous negative pressure (CNP) in an Isolette negative pressure ventilator for refractory hypoxemia while receiving intermittent positive pressure mandatory ventilation. All patients had severe lung disease as documented by an increased oxygenation index and bilateral pulmonary interstitial emphysema on x-ray examination. Patients were separated into two groups--survivors and nonsurvivors, with six patients in each group. Initiation of CNP resulted in a significant initial improvement in oxygenation in both groups seen as a 52% decrease in the oxygenation index in survivors and a 57% decrease in the oxygenation index in nonsurvivors (P less than .05). The survivors characterized themselves by showing a further sustained improvement in the oxygenation index--31.4 +/- 9.1 to 6.9 +/- 5.0 (P less than .01)--and a significant decrease in the mean airway pressure--11.6 +/- 4.6 cm H2O to 5.0 +/- 1.9 cm ...