Persistent Left Superior Vena Cava

Persistent left superior vena cava (PLSVC) is a common cardiac anomaly associated with congenital heart diseases. A diagnosis of PLSVC usually warrants a detailed fetal echocardiography. Lesser known associations are the extra cardiac anomalies notably the upper airway and the gastrointestinal tract anomalies. We highlight here the importance of detailed fetal assessment for extra cardiac anomalies in addition to fetal echocardiography in fetuses diagnosed with PLSVC. We hereby present a preterm infant who presented with a triad of PLSVC, laryngeal atresia, and esophageal atresia.

Congenital tuberculosis in an extremely preterm infant conceived after in vitro fertilization: case report

Background

Congenital tuberculosis is a rare manifestation of tuberculosis. The diagnosis is often delayed, especially in preterm neonates because of the non-specific clinical presentation and the lack of awareness of maternal disease prior to pregnancy.

Case Presentation

We report a case of congenital tuberculosis in an infant born at 24 weeks of gestation to a mother who presented with uncontrolled seizures during preterm labor. Maternal diagnosis was initially made by placental pathology, and later confirmed by isolation of Mycobacterium tuberculosis in urine, gastric aspirates and sputum. Full screening was performed on the newborn infant, and both mother and infant were successfully treated for tuberculosis with a four drug regimen.

Conclusion

Pregnancy can exacerbate latent tuberculosis and women originating from endemic areas are especially susceptible. The best way to prevent congenital tuberculosis is to have a high index of suspicion and identify and treat tuberculosis in pregnant women.

Intravenous immunoglobulin in the management of a rare cause of hemolytic disease of the newborn: Anti-SARA antibodies

Hemolytic disease of newborn (HDN) is a condition that develops in a fetus, when the IgG molecules produced by the mother pass through the placenta and attack the fetal red blood cells. HDN can occur due to Rh and ABO incompatibilities between the mother and the fetus as well as due to other allo-immune antibodies belonging to Kell (K and k), Duffy (Fya), Kidd (Jka and Jkb), and MNS (M, N, S, and s) systems. Role of intravenous immunoglobulin in management of HDN is not clear.SARA red blood cell antigen, first discovered in 1990 is a low frequency antigen. We report, a multiparous female whose pregnancy was complicated by HDN due to anti-SARA antibodies requiring both exchange transfusion and intravenous immunoglobulin. The response was sustained after intravenous immunoglobulin (IVIG) rather than after exchange transfusion.

Changes in Pulmonary Function After A Caffeine Loading Dose and Extubation Outcome in Preterm Infants with Respiratory Distress Syndrome

BACKGROUND: Prolonged endotracheal intubation in preterm infants leads to adverse outcomes including bronchopulmonary dysplasia, pneumonia and sepsis. Extubating preterm infants early can lead to apneas, respiratory distress and hypoxemia with reintubation, a destabilizing and traumatic event. Identifying readiness for extubation would avoid these harmful events. Current clinical criteria perform poorly in predicting extu-bation outcome in preterm infants. Caffeine is used to facilitate extubation and also affects pulmonary function.

OBJECTIVES: To determine pulmonary functions before and after a caffeine loading dose in preterm infants < 31 weeks gestation with respiratory distress syndrome (RDS) undergoing their first trial of extubation and use them to predict extubation outcome.

DESIGN/METHODS: We determined dynamic compliance (Cdyn), tidal volume (TV), minute ventilation (MV), and dynamic airway resistance (Rdyn) before and after a loading dose of 10 mg/kg of caffeine base in preterm infants <31 weeks gestation with RDS prior to extubation. These measurements were taken as an average of ten non-distorted breaths with < 10% endotracheal air leak. Infants were ventilated with the EvitaXl Neo (Draeger, Germany). Pulmonary function readings were downloaded from the ventilator. Extubation failure was defined as the need for reintubation within 72 h after extubation. Exclusion criteria included grade 3-4 intra-ventricular hemorrhage, sedation, pneumothorax, medications affecting pulmonary function, chromosomal and congenital malformations. Mann Whitney test was used for continuous variables and the χ2 or Fisher’s exact test for dichotomous data. A p value <0.05 was considered significant.

RESULTS: Blood gas values and ventilator parameters were similar between the groups before extubation.There was significant improvement in pulmonary function after a loading dose caffeine. Amongst pulmonary functions, ratio of Cdyn before and after caffeine performed best in predicting extubation outcome with an area under the curve of 0.85 (95% CI 0.79-0.94).

CONCLUSION: Caffeine improves pulmonary function in preterm infants. A ratio of dynamic compliance before and after caffeine best predicted extu-bation outcome. Our results need validation in a prospective study.

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Neonatal hypercalcemia secondary to subcutaneous fat necrosis successfully treated with pamidronate: a case series and literature review

Subcutaneous fat necrosis (SCFN) is a noninfectious panniculitis that occurs in term infants who experience significant distress in the 1st weeks of life, including hypoxic ischemic encephalopathy (HIE). Since the introduction of therapeutic hypothermia for HIE, there have been a few published case reports of SCFN, following this modality of treatment. Although, most cases of SCFN resolve spontaneously, SCFN may be associated with hypercalcemia, which may sometimes reach dangerous levels. Approaches used for the management of this potentially life-threatening condition, include hyperhydration, calciuric diuretics, corticosteroids, and in more resistant cases pamidronate, a bisphosphonate. We report our experience on the use of pamidronate in two cases of severe hypercalcemia associated with SCFN following therapeutic hypothermia for HIE. We believe that with increasing use of therapeutic hypothermia for HIE, clinicians are likely to encounter this condition more frequently.

Assessment of initial vancomycin dosing in neonates

BACKGROUND

Vancomycin is recommended for optimal treatment of late-onset sepsis caused by coagulase-negative Staphylococcus in neonates.

OBJECTIVES

To assess the performance of an empirical vancomycin dosing regimen in achieving target trough levels, and to revise this regimen if needed.

METHODS

Data regarding doses and levels were collected and pharmacokinetic parameters were calculated, where possible, for neonates receiving vancomcyin in a neonatal intensive care unit. The primary measure was the percentage of neonates with initial prevancomycin levels of <10 mg/L, 10 mg/L to 20 mg/L and >20 mg/L. Secondary measures included the percentage of neonates with extrapolated trough levels in these ranges, total daily doses that achieved target levels (10 mg/L to 20 mg/L) and total daily doses/dosing intervals that were pharmacokinetically predicted to achieve trough levels of 15 mg/L.

RESULTS

Of 153 infants started on the empirical regimen (15 mg/kg/day to 45 mg/kg/day, depending on postnatal age and weight), 34.2% initially achieved target trough levels (mean 8.7 mg/L). Analysis of actual doses and pharmacokinetically predicted doses required to reach target levels suggested increasing the empirical dosing for all neonatal age groups. The revised regimen used in the present study (20 mg/kg/day to 40 mg/kg/day, depending on postmenstrual age and postnatal age) was predicted to result in 72% of infants achieving initial target trough levels (mean 15.4 mg/L).

CONCLUSIONS

A revised empirical vancomycin dosage regimen for neonates was required based on poor achievement of target trough levels (10 mg/L to 20 mg/L) using the previous regimen. The modified regimen is predicted to reach target trough levels more often and increase the mean initial trough levels achieved. This regimen requires clinical validation in an independent cohort in the future.

Assessment of initial vancomycin dosing in neonates

BACKGROUND

Vancomycin is recommended for optimal treatment of late-onset sepsis caused by coagulase-negative Staphylococcus in neonates.

OBJECTIVES

To assess the performance of an empirical vancomycin dosing regimen in achieving target trough levels, and to revise this regimen if needed.

METHODS

Data regarding doses and levels were collected and pharmacokinetic parameters were calculated, where possible, for neonates receiving vancomcyin in a neonatal intensive care unit. The primary measure was the percentage of neonates with initial prevancomycin levels of <10 mg/L, 10 mg/L to 20 mg/L and >20 mg/L. Secondary measures included the percentage of neonates with extrapolated trough levels in these ranges, total daily doses that achieved target levels (10 mg/L to 20 mg/L) and total daily doses/dosing intervals that were pharmacokinetically predicted to achieve trough levels of 15 mg/L.

RESULTS

Of 153 infants started on the empirical regimen (15 mg/kg/day to 45 mg/kg/day, depending on postnatal age and weight), 34.2% initially achieved target trough levels (mean 8.7 mg/L). Analysis of actual doses and pharmacokinetically predicted doses required to reach target levels suggested increasing the empirical dosing for all neonatal age groups. The revised regimen used in the present study (20 mg/kg/day to 40 mg/kg/day, depending on postmenstrual age and postnatal age) was predicted to result in 72% of infants achieving initial target trough levels (mean 15.4 mg/L).

CONCLUSIONS

A revised empirical vancomycin dosage regimen for neonates was required based on poor achievement of target trough levels (10 mg/L to 20 mg/L) using the previous regimen. The modified regimen is predicted to reach target trough levels more often and increase the mean initial trough levels achieved. This regimen requires clinical validation in an independent cohort in the future.

Coagulase-negative staphylococcus sepsis in preterm infants and long-term neurodevelopmental outcome

OBJECTIVE

The objective of this study was to examine the impact of Coagulase-negative staphylococcus (CoNS) sepsis in preterm infants on the neurodevelopmental outcomes at 30 to 42 months corrected age (CA).

STUDY DESIGN

This is a retrospective cohort study. All preterm infants born at <29 weeks gestational age between 1995 and 2008 and had a neurodevelopmetnal assessment at 30 to 42 months CA were eligible. The neurodevelopmetnal outcomes of infants exposed to CoNS sepsis were compared with infants unexposed to any type of neonatal sepsis.

RESULT

A total of 105 eligible infants who were exposed to CoNS sepsis were compared with 227 infants with no neonatal sepsis. In univariate analysis, infants with CoNS sepsis were more likely to have total major disability (odds ratio (OR)=1.9; 95% CI: 1.07 to 3.38) and cognitive delay (OR=2.53; 1.26 to 5.14).There was no significant difference in the incidence of cerebral palsy, blindness and deafness between the two groups. After correcting for potential confounders, CoNS sepsis was associated with increased risk of cognitive delay (adjusted odds ratio (aOR)= 2.23; 95% CI 1.01 to 4.9), but not with the total major disability (aOR=1.14; 95% CI: 0.55 to 2.34).

CONCLUSION

Our study suggests that CoNS sepsis in preterm infants might be associated with increased risk for cognitive delay at 36 months CA.

The mystery of persistent pulmonary hypertension: an idiopathic infantile arterial calcification

BACKGROUND

Idiopathic infantile arterial calcification (IIAC) is a rare autosomal recessive disorder, characterized by wide spread calcifications in arterial walls, leading to vaso-occlusive ischaemia of multiple organs. Mortality is high, and there is no definitive treatment.

CASE PRESENTATION

A male neonate, 36+5 weeks gestation, 2.81 kg, was admitted to NICU for respiratory distress. At one hour of age, he was noted to be pale, hypoperfused, with weak pulses, a hyperdynamic precordium and a grade IV/VI pansystolic murmur. The rest of his examination was normal. A chest X-ray showed massive cardiomegaly and pulmonary oedema. An echocardiogram (ECHO) indicated moderate persistent pulmonary hypertension (PPHN) of unclear etiology. A diagnosis of Idiopathic infantile arterial calcification was made and a trial of Editronate therapy was given without success.

CONCLUSION

IIAC is a rare disorder, it should be considered whenever a neonate presents with unexplainable cardiac failure, PPHN, echogenic vessels on X-ray/ultrasound and, or concentric hypertrophic ventricles on ECHO. Serial antenatal ultrasound findings of echogenic cardiac foci should raise the suspicion of IIAC. Further studies to determine the long term effects of Editronate on vascular calcifications, disease outcome, and other treatment options are needed.

Carboxyhemoglobin levels in umbilical cord blood of women with pre-eclampsia and intrauterine growth restriction

OBJECTIVE

Pre-eclampsia (PE) and intrauterine growth restriction (IUGR) are associated with abnormal placentation. Heme oxygenase (HO) and carbon monoxide (CO) are involved in normal placental development and function and vasomotor control in the placenta. The objective of our study was to measure CO levels, as assessed by carboxyhemoglobin (COHb) levels in the umbilical cord arterial blood of women with PE, normotensive IUGR (<10th percentile for birth weight), and normotensive pregnancies with appropriate-for-gestational age (AGA) infants.

DESIGN AND METHODS

We prospectively analyzed COHb levels in the umbilical arterial blood of women with PE, normotensive IUGR, and normotensive AGA pregnancies. Exclusion criteria included cigarette smoke exposure, hemolytic disorders, a positive direct anti-globulin test, chronic hypertension, fever, and any significant medical illness. COHb levels were measured using the ABL 725 blood gas analyzer.

RESULTS

There were 41 women in the normotensive AGA group, 42 in the PE group, and 36 in the normotensive IUGR group. Maternal age, mode of delivery, gravidity, parity, and gender of the infants were similar in the three groups. Gestational age and birth weight were significantly higher in the normotensive AGA group compared with the other two groups. COHb levels were significantly lower in the PE group compared with the normotensive AGA group (0.38±0.06% vs. 0.77±0.11%, P<0.05). COHb levels, although lower in the normotensive IUGR group compared with the normotensive AGA group, did not reach statistical significance.

CONCLUSION

Our data suggests the HO-CO system may have a role in the pathogenesis of PE. We also, for the first time, provide information on umbilical arterial COHb levels in normotensive IUGR pregnancies.

Extended interval dosing of gentamicin in premature neonates ≤ 28-week gestation

AIM

To evaluate an extended interval dosing (EID) regimen of gentamicin in neonates ≤28-week gestation.

METHODS

In 2008, an EID regimen for gentamicin was introduced for all neonates admitted to the NICU in Calgary. The dosing interval was based on a 22 h level after the first dose of 5mg/kg. We conducted an observational study in 33 infants ≤28-week gestation on the EID regimen from the first day of life and compared gentamicin peak and trough levels with a historical control of 34 infants who received gentamicin in a dose of 2.5 mg/kg every 24 h (TID, traditional interval dosing).

RESULTS

In the EID group, based on the 22 h level, dosing interval was 36 h in 20 neonates and 48 h in 13 neonates. All neonates, except one, achieved therapeutic peak and trough levels. Compared to the TID group, the EID group had higher peak levels (median 9.8 μg/mL vs. 4.6 μg/mL, p < 0.001) with no difference in trough levels. With target peak levels of 5-12 μg/mL and trough levels of <2 μg/mL, a higher proportion of neonates in the TID group would need dose adjustment.

CONCLUSION

In neonates ≤ 28-week gestation, an EID regimen from day one of life, using a single level 22 h after the first dose for dosing interval, achieves therapeutic peak and trough levels and more optimum peak levels as compared to a TID regimen.

Validation of a dosage individualization table for extended-interval gentamicin in neonates

BACKGROUND

Extended-interval aminoglycoside dosing is increasingly used in neonates; however, guidance on how to monitor concentrations and adjust dosages accordingly is limited.

OBJECTIVE

To prospectively validate the use of a 22-hour gentamicin concentration dosing table for the individualization of extended-interval dosing in the neonatal population by examining the peak and trough concentrations achieved through its use.

METHODS

A prospective observational study was carried out on gentamicin concentrations achieved using a 22-hour post-first-dose gentamicin concentration dosing table for determining dosing intervals in neonates. Neonates (N = 104) in the first week of life, gestational age 23 weeks to full term, in level II and III neonatal intensive care units were included. Neonates were given gentamicin 5 mg/kg intravenously; a table using 22-hour post-first-dose gentamicin concentrations was then used to individualize dosing intervals. Pre- and post-serum gentamicin concentrations on the dosing interval indicated were measured with the second or third doses and used to calculate the peak and trough concentrations achieved.

RESULTS

Use of the 22-hour post-first-dose gentamicin concentration dosing table resulted in dosing intervals that provided appropriate peak (mean 10.55 mg/L) and trough (mean 0.75 mg/L) concentrations (with second or third doses) in all neonates. All patients had trough concentrations less than 2 mg/L, and 73% had a trough concentration less than 1 mg/L. No peak concentrations were less than 5 mg/L, 82% of patients had a peak concentration from 5 to 12 mg/L, and the remaining 18% had concentrations from 12.1 to 16 mg/L. Peak and trough concentrations were similar across all gestational ages.

CONCLUSIONS

Use of a 22-hour post-first-dose gentamicin concentration dosing table to individualize extended-interval gentamicin dosages in neonates resulted in appropriate peak and trough concentrations in all neonates studied. Use of this table will result in appropriate extended-interval aminoglycoside dosages in neonates early in treatment, using a single serum concentration.

Prenatal cigarette smoke exposure and postnatal respiratory responses to hypoxia and hypercapnia

Prenatal cigarette smoke (CS) exposure, in combination with hypoxia and/or hyperthermia can lead to gasping and attenuated recovery from hypoxia in 7 days old rat pups. We studied 95 unanesthetized spontaneously breathing 14 days old rat pups to investigate if the destabilizing effects of increased ambient temperature and prenatal CS exposure on respiratory control observed in 7 days old rats were still evident at day 14. This postnatal age was selected as it is beyond the analogous risk period for SIDS in human. Furthermore, we investigated if the breathing responses to hypercapnia are affected by prenatal CS exposure. Since high ambient (HA) temperature can lead to gasping and aberrant respiratory control, we recorded respiratory patterns at low (24-25°C) and high (29-30°C) ambient temperatures, and under hypoxic or hypercapnic states. No gasping was observed in 14 days old rat pups. During hypoxia, breathing frequency increased in the CS-exposed group under low and HA temperatures. Rectal temperature decreased only in the sham group in response to low ambient temperature hypoxia. At HA temperature, breathing frequency increased in both sham and CS-exposed groups during hypercapnia, however, it remained elevated during washout period only in the sham group. We demonstrate that prenatal CS exposure continues to have profound effects on respiratory and thermoregulatory responses to hypoxia and hypercapnia at day 14. The attenuated respiratory and thermoregulatory responses to acute hypoxia and hypercapnia on day 14 demonstrate a strong interaction between CS exposure, respiratory control, and thermoregulation during postnatal maturation.

Ionized calcium levels in umbilical cord blood of women with preeclampsia and normotensive pregnancies

Calcium is essential for normal fetal growth and development. During intrauterine life, the fetus is entirely dependent on the mother and a normally functioning placenta for calcium accretion. Preeclampsia is associated with abnormal calcium metabolism and placental dysfunction. The objective of our study was to investigate ionized calcium levels in the umbilical cord arterial blood of women with preeclampsia and normotensive pregnancies. There were 24 women in the preeclampsia group and 25 in the normotensive group. There was no difference in the cord pH and fetal growth restriction between the two groups. Ionized calcium levels were significantly lower in the preeclampsia group (p < 0.001). Our results emphasize the need for further studies on the calcium status of infants born to mothers with preeclampsia.