Early diagnosis of congenital heart disease

Early detection of significant congenital heart disease: The contribution of fetal cardiac ultrasound and newborn pulse oximetry screening

Fetal cardiac and newborn pulse oximetry screening has greatly facilitated the detection of cardiac abnormalities, which may be serious with potentially dire neonatal consequences. The prenatal diagnosis of a serious cardiac abnormality allows the attending obstetrician to organise the much safer in-utero transfer of the fetus for delivery at a tertiary centre, particularly if there is evidence of a duct-dependent lesion that may require the infusion of Prostaglandin E1 to maintain duct patency pending surgical intervention. Newborn pulse oximetry alerts the paediatrician that the baby may have a significant cardiac abnormality, which warrants further elucidation prior to discharge, rather than for the baby to represent unwell a few days later. Despite these advances, serious cardiac abnormalities may be missed on screening. Their detection then falls back onto the clinical acumen of the attending paediatrician/family physician to review the history, carefully elicit and evaluate the clinical signs further aided by whatever investigations that may be available at the birthing hospital, frequently less resourced than the tertiary centres. At the outset, a brief synopsis is provided of the clinical findings that may point to a cardiac abnormality. That is followed by a critical review of the accuracy of prenatal and newborn pulse oximetry screening with emphasis on the lesions that may be missed. Suggestions are made as to how to improve the diagnostic accuracy.

Improving diagnostic accuracy in neonates with left heart obstruction in a transport setting

AIM

Differentiating left heart obstruction (LHO) from other severe illness in the neonatal period is challenging, and important for guiding clinical management. The aim of this study was to identify factors distinguishing LHO from non-LHO in neonates.

METHODS

A retrospective, cohort study of neonates referred to the Newborn and Paediatric Emergency Transport Service, New South Wales, with suspected LHO during the epoch 1996-2016.

RESULTS

A total of 273 neonates were included; 240 with confirmed LHO. Administration of prostaglandin E₁ to infants with a structurally normal heart was not associated with impaired acid-base or oxygenation status. Pre-transport diagnostic accuracy of LHO was 74.4%; sensitivity 84.5%, positive predictive value 86.0%. On multivariable logistic regression, hepatomegaly (odds ratio 2.54; 95% confidence interval 1.05-6.16) was associated with confirmed LHO.

CONCLUSIONS

A low threshold for prostaglandin E₁ infusion should be maintained in infants with suspected LHO. Hepatomegaly is associated with a diagnosis of LHO and may be more useful than other parameters in predicting the condition.

Clinical Screening for Congenital Heart Disease in Newborns at a Tertiary Care Hospital of a Developing Country

Objective: To screen all newborns admitted to a tertiary care hospital to rule out congenital heart disease before discharge and to find out the utility of pulse oximetry to detect congenital heart disease.

Methodology: This prospective study was done at Aga Khan University Hospital from January 2014 to December 2014 in 1,650 newborns over a period of 12 months. Pulse oximetry and clinical examination were done. Persistent oxygen saturation less than 95% was considered as positive pulse oximetry. Newborns who had positive pulse oximetry or abnormal clinical examinations findings were subjected to echocardiography.

Results: Pulse oximetry was performed on 1,650 newborns, out of which 25 (1.5%) had congenital heart disease. Positive pulse oximetry cases were 16 (0.97%), out of which 10 had only positive pulse oximetry (negative clinical examination). Positive clinical examination cases were 45 (2.7%), out of which 39 cases had only positive clinical examinations (negative pulse oximetry). Six newborns had both positive pulse oximetry and positive clinical examination. Out of the 25 diagnosed cases of congenital heart disease, ventricular septal defect (VSD) was the most common congenital heart disease, followed by patent ductus arteriosus (PDA). The sensitivity, specificity, positive predictive value, and negative predictive value of pulse oximetry were 32%, 99.5%, 50%, and 98.9% respectively.

Conclusion: In the community setting of a developing country, a combination of pulse oximetry screening and clinical examination are better at detecting congenital heart defects than either test alone.

Congenital heart disease in twins: The contribution of type of conception and chorionicity

BACKGROUND

Increased incidence of congenital heart disease (CHD) has been reported in the offspring of monochorionic twin gestations. Assisted reproductive technology (ART), which is related to increased rates of twinning, has also been associated with higher risk of birth defects. We studied the incidence of CHD in a cohort of twins to clarify the contribution of type of conception and chorionicity.

METHODS

Data concerning 874 live-born twins of which at least one was admitted in our Neonatal Unit during 1995-2012 were analysed. Forty-five % (N=197) of the gestations resulted from ART (in vitro fertilisation or intracytoplasmic sperm insertion).

RESULTS

In the ART group 32/389 (8.2%) had CHD compared to 21/485 (4.3%) infants conceived naturally (OR 1.90, 95%CI 1.08-3.34, p=0.024). Spontaneous-conception gestations had higher incidence of monochorionic placentation (47/245 versus 4/197, p<0.001), and included younger mothers (29.1±5.2 versus 33.9±5.5years, p<0.001) who had higher parity (median 2 [range 1-7] versus 1 Pinborg (2005), Blondel and Kaminski (2002), Knopman et al. (2014), Kyvik and Derom (2006) ; p<0.001). Multivariable logistic regression analysis showed that ART (OR 2.60, 95% CI 1.24-5.45) and monochorionicity (OR 3.49, 95% CI 1.57-7.77) were significant determinants of CHD, independently of maternal age, parity, and the gender of the offspring.

CONCLUSIONS

We confirmed that monochorionic twins have increased risk of CHD and we documented a higher incidence of CHD in ART twins independently of chorionicity. We suggest improvement of echocardiographic skills of health care professionals involved in prenatal screening and foetal cardiology referral of ART dichorionic twins with suspicious findings at screening, in addition to all monochorionic gestations.

A Simple Effective Protocol to Increase Prenatal Detection of Critical Congenital Heart Disease

Prenatal diagnosis of congenital heart disease (CHD) during routine obstetric sonography has been aptly named the sonographer’s Achilles heel. Although CHD occurs more commonly than any other major congenital abnormality, the detection rate remains low. The goal of this study was to improve the prenatal diagnosis of CHD during routine obstetric sonography through the development and implementation of a simple and effective screening protocol.

Neonatal screening for critical cardiovascular anomalies using pulse oximetry

INTRODUCTION

Babies with cardiac anomalies are often asymptomatic at birth, and many remain undetected despite routine newborn examination. We retrospectively assessed the effect of routine pulse oximetry in detection of such anomalies from a hospital birth population of 31 946 babies born between 1 April 1999 and 31 March 2009.

METHOD

29 925 babies who were not admitted to the neonatal unit at birth underwent postductal oxygen saturation measurement before discharge. If saturation was below 95% an examination was performed. If this was abnormal or saturation remained low, an echocardiogram was performed. All babies with cardiac anomaly diagnosed before 1-year were identified from the region's fetal abnormality database.

RESULTS

Critical anomalies affected 27 infants (1 in 1180); 10 identified prenatally, 2 after echocardiogram was performed because of other anomalies, 2 in preterm infants, 2 when symptomatic before screening, 5 by oximetry screening, 1 when symptomatic in hospital after a normal screen and 5 after discharge home. Serious anomalies affected 50 infants (1 in 640); 8 identified antenatally, 7 because of other anomalies, 3 in the neonatal unit, 5 by pulse oximetry screening, 11 by routine newborn examination, and 16 after discharge home.

CONCLUSIONS

Routine pulse oximetry aided detection of 5/27 of critical and 5/50 of serious anomalies in this sample, but did not prevent five babies with critical and 15 with serious anomalies being discharged undiagnosed. Results from screening over 250 000 babies have now been published, but this total includes only 49 babies with transposition, and even smaller numbers of rarer anomalies.

Reappraisal of the prostaglandin E1 dose for early newborns with patent ductus arteriosus-dependent pulmonary circulation

OBJECTIVES

The usual initial dose of prostaglandin E1 (PGE1) for ductal-dependent congenital heart disease (CHD) is 50-100 ng/kg/minute. The aim of this study was to review our experience of a low initial dose of PGE1 treatment in early newborns with congenital heart disease and patent ductus arteriosus (PDA)-dependent pulmonary flow.

METHODS

We reviewed the clinical data of 33 newborns with CHD and PDA-dependent pulmonary circulation who were admitted from January 2005 to December 2010. Clinical parameters were collected, including, PGE1 dosage, oxygenation condition, vital signs, and other related clinical parameters during admission. Echocardiography was employed to assess the status of the PDA as clinically indicated.

RESULTS

Thirty-three newborns, including 17 males and 16 females, with CHD and PDA-dependent pulmonary circulation were enrolled in the study. Their mean age was 2.9 ± 5.1 (within the range of 1-26) days with a median of 1.0 day. Among the 33 cases, 25 were diagnosed with pulmonary atresia and eight with critical pulmonary stenosis. Twenty-five of our patients were treated with the initial low-dosage regimen of 20.0 ± 7.4 ng/kg/minute in our neonatal intensive care unit. None of these 25 patients with had significant apnea necessitating intubation and none had hypotension, fever, convulsion or cortical hyperostosis. Three of the eight patients who were treated with high-dose PGE1 (39 ± 13.2 ng/kg/minute) before referral to our unit had apnea and intubation after PGE1 use. All patients had adequate PDA patency with a low maintenance dose of 10.5 ± 5.3 ng/kg/minute before operation under our protocol.

CONCLUSION

In our experience, adequate PDA flows in early newborns with CHD and PDA-dependent pulmonary circulation could be achieved at a much lower dose than recommended in the literature. The lower dose of PGE1 also causes much fewer complications, such as apnea, fever, and hypotension. For early newborns with CHD and PDA-dependent pulmonary circulation, treatment with a lower initial dose of PGE1 of 20 ng/kg/minute and a maintenance dose of 10 ng/kg/minute is recommended.

Awareness of fetal echo in Indian scenario

Background:

Fetal echocardiography is a well established sensitive tool to diagnose congenital heart disease (CHD) in utero. One of the determinants of effective utilization of fetal echocardiography is its awareness in the general population. The present hospital based study was undertaken to assess the awareness of the need for fetal echocardiography amongst Indian parents.

Methods:

One thousand one hundred and thirty eight consecutive parents who visited the pediatric cardiology outpatient department of a tertiary care centre over a period of two months were asked to fill up a questionnaire that included their demographic data, educational status, history of CHD in children, awareness of fetal echocardiography and source of information and timing of fetal echocardiogram if performed. The data was categorized and awareness was noted in different groups.

Results:

The awareness in the study population was 2.2%. Awareness was found to be similar across the study population irrespective of the demographics and high risk status of the parents.

Conclusions:

The awareness of fetal echocardiography, an important tool in reducing the incidence of complex CHD, thereby impacting public health, is alarmingly low in the population studied. Appropriate action to increase awareness of fetal echocardiography needs to be looked into.

Fetal cardiac screening and variation in prenatal detection rates of congenital heart disease: why bother with screening at all?

Antenatal screening for fetal cardiac abnormalities was introduced over 25 years ago, yet detection of congenital heart disease before birth remains a challenge. While experienced tertiary centers report a high level of diagnostic accuracy, with most major forms of congenital heart disease being detectable before birth, the overall detection rate remains low. Pregnancies at increased risk of having an affected baby are referred to tertiary centers for fetal ECG, but most cases of congenital heart disease will occur in low-risk pregnancies. These cases will only be detected by screening the low-risk population at the time of routine obstetric scanning. Many obstetric ultrasound units have learnt to successfully obtain, and correctly interpret, views of the heart, including the four-chamber view and outflow tract views. However, standards for doing this are not uniform, nationally or internationally, so there is a significant variation in detection rates across individual countries and between different countries. Early diagnosis of babies with lesions that can result in cardiovascular collapse and death, could improve their survival as well as reducing morbidity. In addition, detection of a cardiac abnormality during pregnancy allows time to prepare parents for the likely course of events after birth. It also facilitates detection of other abnormalities in the baby and gives parents a choice, even if the choice is difficult and unwelcome. As well as providing parents with accurate and up-to-date information regarding the their baby’s abnormality, it is vital to provide continuing support to help them deal with the problem, regardless of what decisions they make. Much work remains to establish a uniform standard for antenatal detection of cardiac abnormalities. More recent national guidelines for examining the fetal heart along with formalized auditing processes should help to achieve this, although considerable time and effort will be required, particularly with regard to the teaching and training required.

Respiratory problems in children with Down syndrome

Down syndrome is associated with a significant health burden, which is particularly apparent in young children who will frequently present with cardiac and respiratory problems. Respiratory presentations include problems related to structural abnormalities of the airways and lungs, glue ears, recurrent lower respiratory tract infections and obstructive sleep apnoea. These conditions are readily identifiable and able to be treated. An awareness of the breadth of respiratory problems and a plan to monitor patients with Down syndrome for their development has the potential to improve outcomes.

Pediatric heart murmurs: evaluation and management in primary care

The ability of the NP to discern pediatric heart murmurs is critical for accurate assessment of etiology, appropriate diagnostic testing, and prudent referral when indicated. This review includes an overview of cardiac assessment, distinguishing features of innocent and pathologic murmurs, differential diagnosis of murmurs, and current referral recommendations.

Periconceptional tobacco smoking and isolated congenital heart defects in the neonatal period

BACKGROUND

Tobacco use in pregnancy is considered a human developmental toxicant and potential teratogen. The aim of the study was to test for a possible association between periconceptional tobacco smoking and congenital heart disease (CHD) in the neonatal period.

METHODS

Maternal and infant characteristics of 157 neonates diagnosed with CHD at the University of Patras Medical School were collected and were compared with 208 normal neonates (aged 1-28 days) that were referred for echocardiography during a specified 3-year period.

RESULTS

In neonates with CHD 64 of 157 mothers (40.8%) reported smoking in pregnancy, whereas in the control group 41 of 208 mothers (19.7%) were smokers (p=0.000). Logistic regression analysis with pregestational diabetes, history of influenza-like illness in the first trimester, therapeutic drug exposure in pregnancy, maternal age, parity, family history of CHD, infant gender, prematurity and paternal smoking, as potential confounding factors showed that periconceptional tobacco smoking was associated with increased risk of CHD in the offspring (OR=2.750, 95% CI=1.659-4.476, p=0.00001). The incidence of neonatal heart disease in women who were non-smokers or smoked 1-10 and ≥11 cigarettes per day increased with the level of fetal tobacco exposure (35.8% versus 55.3% versus 64.3%, x2-test=20.303, p=0.000), suggesting a dose effect.

CONCLUSIONS

The results of the study are indicative of an association between periconceptional tobacco exposure and increased risk of CHD in the neonatal period. The potential role of gestational smoking as a risk factor for specific heart defect subgroups requires the conduction of large population based epidemiological studies.

Accuracy of cardiac auscultation in asymptomatic neonates with heart murmurs: comparison between pediatric trainees and neonatologists

The aim of this study was to assess whether cardiac auscultation performed by pediatric trainees and neonatologists can reliably distinguish innocent from pathologic heart murmurs in asymptomatic neonates. From January 2008 to April 2009 the pediatric trainees of our institution were requested to refer all asymptomatic neonates with a murmur and classify the murmurs as "innocent," "pathologic," or "possibly pathologic." Prior to echocardiography, each neonate was evaluated by two experienced neonatologists. The echocardiographic studies of 169 neonates were analyzed. Abnormal cardiac anatomy was found in 55 neonates (32.6%). The overall ability of pediatric trainees in identifying congenital heart disease (CHD) was moderate [area under the curve (AUC) = 0.855] and significantly lower compared to neonatologists (AUC = 0.919, p = 0.007). However, at "lower" levels of clinical confidence (i.e., clinical diagnosis of possibly pathologic murmurs), pediatric trainees had good ability in excluding CHD (sensitivity 94.6%; negative likelihood ratio = 0.09). The ability of cardiac auscultation for diagnosing CHD in asymptomatic neonates is limited and dependent on the physician's experience and level of clinical confidence. Echocardiography should remain an option for all neonates with a possibly pathologic murmur.

Clinical screening for Congenital heart disease at birth: a prospective study in a community hospital in Kerala

OBJECTIVE

To develop a clinical strategy for detection of Congenital heart disease (CHD) in the newborn through a combination of clinical signs and pulse oximetry.

DESIGN

Prospective longitudinal study.

SETTING

Community level hospital in the city of Kochi, Kerala.

PARTICIPANTS AND INTERVENTIONS

All consecutive newborns between June 2006 and February 2009 were prospectively screened for CHD, 48 hours after birth. The on-site pediatrician performed clinical screening. A study nurse recorded pulse oximetry in a lower extremity; value of <94% was defined as abnormal. Echocardiography was performed on site by a trained research officer. A 6-week clinical follow-up evaluation was done for all.

MAIN OUTCOME MEASURE

Detection of CHD by echocardiography.

RESULTS

Of 5487 babies screened, 425 (7.75%) had CHD. 17 (0.31%) had major CHD, two of whom (one ALCAPA and one large VSD) were missed during the initial evaluation. The rest were minor CHD (408 patients, 7.44%), most of which normalized by 6 weeks. On multivariate analysis, murmur, central cyanosis, abnormal precordial pulsations and abnormal pulse oximetry emerged as significant predictors of CHD. The sensitivity of clinical evaluation and pulse oximetry combined was 19% for all CHDs and 20% for major CHD; specificity was 88%.

CONCLUSIONS

In the community setting of a developing country, clinical evaluation and pulse oximetry after birth had a very low sensitivity for detection of CHD. Though an abnormal screening warrants prompt echocardiography, a 6 week clinical evaluation is recommended to ensure that major CHD is not missed.

Echocardiography and management of sick neonates in the intensive care unit

To evaluate the influence of echocardiographic examination in the clinical management of the sick neonate, 241 patients, admitted to the neonatal intensive care unit of a tertiary referral center that had echocardiograms with data available for review, were enrolled in a retrospective study. Asymptomatic murmurs (45%) followed by extracardiac anomalies/dysmorphic features (24%) were the most common clinical indications for requesting an echocardiogram. Congenital structural abnormalities (33%), hemodynamically significant patent arterial duct (3%), persistent pulmonary hypertension of the newborn (6%), and left ventricular dysfunction (3%) were the echocardiographic findings that subgrouped as structural or functional abnormalities. Patent oval foramen and hemodynamically nonsignificant patent arterial duct (20%) and physiologic pulmonary artery stenosis (1%) were categorized as normal structural group. Thirty-four percent of neonates had normal heart anatomy. This investigation changed the clinical management in at least 66% of newborns scanned, including emergency surgical intervention for 7%, medical treatment for 22%, and routine cardiologic follow-up for 37% of patients. Asymptomatic murmur in our critically ill neonates has been associated with a higher incidence of cardiac disease. Hence, echocardiography is an important tool for diagnosis of cardiac abnormalities that can influence the management and outcome of the sick newborn in the intensive care unit. A preliminary echocardiogram performed by the neonatologist under the supervision of a pediatric cardiologist for interpretation and review is an alternate when there is not a cardiologist "in house."

The reliability of a single pulse oximetry reading as a screening test for congenital heart disease in otherwise asymptomatic newborn infants

Routine pulse oximetry has been studied to detect children with otherwise undiagnosed congenital heart disease prior to nursery discharge. The reported sensitivities in asymptomatic patients have been less than expected and vary widely, bringing into question the reliability of the test. The purpose of this study was to assess whether routine pulse oximetry contributes to identifying patients with critical congenital heart disease and to determine the reliability of a single pulse oximeter reading in screening asymptomatic newborn infants. Between December 26, 2003, and December 31, 2005, three hospitals in west central Florida performed a pulse oximetry routinely on all newborns at the time of discharge. Patients diagnosed with critical congenital heart disease during the study period were identified to assess whether the pulse oximetry reading initiated their diagnosis. In one hospital, the pulse oximeter data were evaluated for reliability. Downloaded data were compared to a log compiled by the nursery personnel, first without (phase 1) and then with (phase 2) their knowledge and additional training. Results were characterized as reliable, probe placed but reading not verifiable, or no evidence of probe placement. Of the 7962 infants who received oximetry testing, there were 12 postnatal diagnoses of critical congenital heart disease. None was initially identified by routine pulse oximetry. Pulse oximetry reliability improved substantially between phase 1 and phase 2 (38 v. 60%, p < 0.0001). Optimal reliability (>95%) was obtained by a nurse with a degree of LPN or higher performing an assessment of at least 360 seconds. Routine pulse oximetry was neither reliable nor an important diagnostic tool in our cohort. Important human factors (probe placement time, oximetry training, and nursing degree) impact single determination pulse oximetry reliability. With routine surveillance and quality improvement, the reliability of this test can be increased. Future studies to determine the effectiveness of pulse oximetry screening for the diagnosis of congenital heart disease in the asymptomatic newborn population must address these factors. Until such a study demonstrates acceptable sensitivity and clinical value, universal screening should not be instituted.

Reliability of a single pulse oximetry reading as a screening test for congenital heart disease in otherwise asymptomatic newborn infants: the importance of human factors

BACKGROUND

The use of routine pulse oximetry to detect neonates with undiagnosed congenital heart disease before nursery discharge has been studied. The reported sensitivities with asymptomatic patients have been less than expected and vary widely, bringing into question the reliability of the test. This study aimed to assess whether routine pulse oximetry contributes to identifying patients with critical congenital heart disease, and to determine the reliability of a single pulse oximeter reading for screening asymptomatic newborn infants.

METHODS

Between December 26, 2003 and December 31, 2005, three hospitals in west central Florida performed pulse oximetry routinely on all newborns at the time of discharge. Patients who received a diagnosis of critical congenital heart disease during the study period were identified to assess whether the pulse oximetry reading initiated their diagnosis. In one hospital, the pulse oximeter data were evaluated for reliability. Downloaded data were compared to a log compiled by the nursery personnel, first without (Phase 1) and then with (Phase 2) their knowledge and additional training. The results were characterized as reliable, probe placed but reading not verifiable, or no evidence of probe placement.

RESULTS

Among the 7,962 infants who received oximetry testing, there were 12 postnatal diagnoses of critical congenital heart disease. None was initially identified by routine pulse oximetry. Pulse oximetry reliability improved substantially between Phases 1 and 2 (38% vs 60%; p < 0.0001). Optimal reliability (>95%) was obtained by a nurse with a licensed practical nurse degree or higher performing an assessment of at least 360 s.

CONCLUSION

Routine pulse oximetry was neither reliable nor an important diagnostic tool for our cohort. Important human factors (probe placement time, oximetry training, and nursing degree) have an impact on single-determination pulse oximetry reliability. With routine surveillance and quality improvement, the reliability of this test can be increased. Future studies to determine the effectiveness of pulse oximetry screening for the diagnosis of congenital heart disease in the asymptomatic newborn population must address these factors. Until such a study demonstrates acceptable sensitivity and clinical value, universal screening should not be instituted.

Twenty-year trends in diagnosis of life-threatening neonatal cardiovascular malformations

BACKGROUND

Infants with cardiovascular malformations are usually asymptomatic at birth. Earlier diagnosis is likely to improve outcome.

OBJECTIVE

To examine trends in the diagnosis of potentially life-threatening cardiovascular malformations.

METHODS

Ascertainment of all cardiovascular malformations diagnosed in infancy in the resident population of one English health region between 1985 and 2004. Infants with life-threatening cardiovascular malformations were all with hypoplastic left heart, pulmonary atresia with intact ventricular septum, transposition of the great arteries or interruption of the aortic arch; and those dying or undergoing operation within 28 days with coarctation of the aorta, aortic stenosis, pulmonary stenosis, tetralogy of Fallot, pulmonary atresia with ventricular septal defect or total anomalous pulmonary venous connection.

RESULTS

Cardiovascular malformations were diagnosed in infancy in 4444 of 690,215 live births (6.4 per 1000) and were potentially life threatening in 669 (15%). Overall, 55 (8%) were recognised prenatally, 416 (62%) postnatally before discharge from hospital, 168 (25%) in living infants after discharge and 30 (5%) after death. Antenatal diagnoses increased from 0 to around 20% and no case was first diagnosed after death in the past 6 years. However, the proportion going home without a diagnosis remains around 25%. Malformations most likely to remain undiagnosed at discharge were coarctation of the aorta (54%), interruption of the aortic arch (44%), aortic valve stenosis (40%) and total anomalous pulmonary venous connection (37%).

CONCLUSIONS

One in three infants with a potentially life-threatening cardiovascular malformation left hospital undiagnosed. Better early diagnosis is likely to be achieved by further improvements in antenatal diagnosis and more widespread use of routine pulse oximetry.

Delayed diagnosis of critical congenital cardiovascular malformations (CCVM) and pulse oximetry screening of newborns

OBJECTIVE

Congenital cardiovascular malformations (CCVMs) are relatively common with a prevalence of 5-10 per 1000 live births. Pulse oximetry screening is proposed to identify newborns with critical CCVMs which are missed by routine prenatal ultrasound and by pre-discharge physical examinations. The purpose of this study was to identify the number of infants with a delayed diagnosis of critical CCVMs potentially detectable by pre-discharge pulse oximetry screening.

PATIENTS AND METHODS

Hospital Discharge records in New Jersey from 199-2004 for infants with critical CCVMs were identified using ICD-9 codes. These records were matched to the Electronic Birth Certificate records to identify newborns who were discharged as normal newborns and were later admitted with a diagnosis of critical CCVMs. Chart review was completed on these cases to confirm a delay in diagnosis.

RESULTS

Chart reviews confirmed delayed diagnosis of critical CCVM in 47 infants out of 670,245 births. Coarctation of the Aorta was the most common delayed diagnosis. The age at final diagnosis varied from 3 days to 6.5 months.

CONCLUSIONS

Further examination of pulse oximetry as a routine newborn screening service is warranted. Implementation of pre-discharge pulse oximetry screening for newborns may improve the timely detection of asymptomatic critical CCVMs.

Should pulse oximetry be used to screen for congenital heart disease?

Ten studies (44 969 newborns, 71 severe defects) evaluating the usefulness of neonatal pulse oximetry (PO) screening in timely detection of congenital heart disease (CHD) were reviewed. PO showed a high specificity (99.9-99.99%), and the overall rate of detection of 15 individual defects with PO was 72% (range 46-100%), exceeding that of the clinical examination 58% (9-86%). Similar results were obtained for cyanotic CHD (89% v 69%, respectively). Without PO, discharge of apparently healthy infants with unknown CHD was 5.5 times and 4.1 times more likely in cyanotic CHD and all serious CHD, respectively. The paper describes the technical and practical details of first day and later screening. Diagnosis is reached earliest with first day screening, but it requires more resources. PO screening is not sensitive enough to serve as an independent screen, but along with the clinical examination it helps minimise the morbidity and mortality associated with discharge without diagnosis. Further research is needed for precise delineation of populations that would benefit from PO screening.

How effectively can clinical examination pick up congenital heart disease at birth?

AIMS

To assess what proportion of all cardiac abnormality can be suspected at birth when all clinical examination before discharge is undertaken by a small stable team of clinicians.

METHODS

A prospective audit of all the 14 572 births in a maternity unit only staffed by nurse practitioners between 1996 and 2003.

RESULTS

1.2% of all babies born in the unit were found to have a structural defect (as confirmed by echocardiography) within a year of birth. The number not suspected before discharge declined over time, and only 6% were first suspected after discharge in the last four years of this eight year study. Four potentially life threatening conditions initially went unsuspected in 1996-8, but none after that. A policy of referring every term baby with a murmur at 1 day of age that was still present at 7-10 days resulted in 4.2% requiring cardiac referral; 54% of these babies still had a murmur when assessed one to two weeks later, and 33% had a structural defect. Parents said in independent, retrospectively conducted, interviews that they found it confidence building to have any possible heart defect identified early and the cause of any murmur clearly and authoritatively explained.

CONCLUSIONS

Effective screening requires experience and a clear, structured, referral pathway, but can work much better than most previous reports suggest. Whether staff bring a medical or nursing background to the task may well be of less importance.

Cell type-specific over-expression of chromosome 21 genes in fibroblasts and fetal hearts with trisomy 21

Background

Down syndrome (DS) is caused by trisomy 21 (+21), but the aberrations in gene expression resulting from this chromosomal aneuploidy are not yet completely understood.

Methods

We used oligonucleotide microarrays to survey mRNA expression in early- and late-passage control and +21 fibroblasts and mid-gestation fetal hearts. We supplemented this analysis with northern blotting, western blotting, real-time RT-PCR, and immunohistochemistry.

Results

We found chromosome 21 genes consistently over-represented among the genes over-expressed in the +21 samples. However, these sets of over-expressed genes differed across the three cell/tissue types. The chromosome 21 gene MX1 was strongly over-expressed (mean 16-fold) in senescent +21 fibroblasts, a result verified by northern and western blotting. MX1 is an interferon target gene, and its mRNA was induced by interferons present in +21 fibroblast conditioned medium, suggesting an autocrine loop for its over-expression. By immunohistochemistry the p78^MX1 protein was induced in lesional tissue of alopecia areata, an autoimmune disorder associated with DS. We found strong over-expression of the purine biosynthesis gene GART (mean 3-fold) in fetal hearts with +21 and verified this result by northern blotting and real-time RT-PCR.

Conclusion

Different subsets of chromosome 21 genes are over-expressed in different cell types with +21, and for some genes this over-expression is non-linear (>1.5X). Hyperactive interferon signaling is a candidate pathway for cell senescence and autoimmune disorders in DS, and abnormal purine metabolism should be investigated for a potential role in cardiac defects.

The contribution of pulse oximetry to the early detection of congenital heart disease in newborns

Approximately half of all newborns with congenital heart disease are asymptomatic in the first few days of life. Early detection of ductal-dependant cardiac malformations prior to ductal closure is, however, of significant clinical importance, as the treatment outcome is related to the time of diagnosis. Pulse oximetry has been proposed for early detection of congenital heart disease. The aims of the present study were: 1) to determine the effectiveness of a pulse-oximetric screening performed on the first day of life for the detection of congenital heart disease in otherwise healthy newborns and 2) to determine if a pulse-oximetric screening combined with clinical examination is superior in the diagnosis of congenital heart disease to clinical examination alone. This is a prospective, multi-centre study. Postductal pulse oximetry was performed between six and twelve hours of age in all newborns of greater than 35 weeks gestation. If pulse-oximetry-measured arterial oxygen saturation was less than 95%, echocardiography was performed. Pulse oximetry was performed in 3,262 newborns. Twenty-four infants (0.7%) had repeated saturations of less than 95%. Of these infants, 17 had congenital heart disease and five of the remaining seven had persistent pulmonary hypertension. No infant with a ductal-dependant or cyanotic congenital heart disease exhibited saturation values greater or equal to 95%.

CONCLUSION

postductal pulse-oximetric screening in the first few days of life is an effective means for detecting cyanotic congenital heart disease in otherwise healthy newborns.

Unsuspected neonatal killers in emergency medicine

A neonate presenting to the emergency department can present a challenge to even the most experienced clinician. This article has focused on four deceiving and potentially devastating neonatal diseases. 1. Neonatal herpes is a potentially devastating illness without pathognomonic signs or symptoms. Early recognition and therapy can reduce mortality markedly. Although no specific sign or symptom is diagnostic,the diagnosis should be strongly considered in the presence of HSV risk factors, atypical sepsis, unexplained acute hepatitis, or focal seizure activity. Acyclovir therapy should be initiated before viral dissemination or significant CNS replication occurs. 2. Pertussis is a disease in which infants are at greatest risk of death or severe complication. Neonatal pertussis often presents in an atypical manner, lacking the classic signs and symptoms such as the "whoop."More common signs and symptoms include cough, feeding difficulty,low-grade fever, emesis, increasing respiratory distress, apnea, cyanosis,and seizures. Management should include hospitalization, supportive care, and antibiotics. 3. Congenital heart defects, particularly ductal-dependent lesions, may have an initial asymptomatic period that culminates in a rapidly progressive and fatal course. A neonate with CHD presents with shock refractory to volume resuscitation or pressor support. Resuscitative efforts are ineffective unless PGE, is administered. 4. Inborn errors of metabolism often are unsuspected because of their protean and heterogeneous nature. Signs and symptoms are subtle,are nonspecific, and often mimic other, more common diseases.An elevated index of suspicion, along with application and correct interpretation of a select few laboratory tests, is the key to making a diagnosis. Therapy is relatively straightforward and focused on resuscitation followed by prevention of catabolism and correction of specifically identified abnormalities. Although these disorders are relatively uncommon, prompt diagnosis and therapy can lead to a decrease in morbidity and mortality. The key is to maintain a high index of suspicion.

Emergency management of collapsed infants

Infants have a limited repertoire of clinical signs in severe illness. Lethargy, respiratory distress, apnoea and poor perfusion can result from a wide spectrum of disorders. Fortunately for the emergency physician, the resuscitation of infants with respiratory and/or circulatory collapse remains universal for all aetiologies (Table 1). Investigations can be initiated during the stabilization of the child that will narrow the differential diagnosis. This article will discuss the resuscitation of collapsed infants, the causative disorders in the first few weeks of life, their early investigation and management.

The use of pulse oximetry to detect congenital heart disease

OBJECTIVE

To evaluate whether pulse oximetry can be used as a screening test to detect congenital heart disease (CHD) in otherwise well newborns before nursery discharge.

METHODS

Births at Lakeland Regional Medical Center (LRMC) who met inclusion criteria, had a single pulse oximeter reading before discharge. A normal reading was considered to be >94%. Abnormal readings were repeated on a different extremity and if still abnormal, an echocardiography was performed. The number of children with CHD and the number of echocardiograms were compared with the previous year at LRMC.

RESULTS

There were 2114 infants enrolled, 88 echocardiograms (3.8%) were performed, and 43 were abnormal (yield = 48.9%), of which 12 required management (13.6%). The control group consisted of 2851 births, producing 108 echocardiograms (3.8%), 42 of which were abnormal (38.9%), and 13 required management (12.0%). No comparisons were significant. During both years, 3 children with cyanotic CHD were born. Routine pulse oximetry failed to detect a child with total anomalous pulmonary venous return. Not a single normal echocardiogram was generated by the study.

CONCLUSION

Routine pulse oximetry was nearly 100% specific for detecting cyanotic CHD; as a result there was no increase in the number of echocardiograms. Routine pulse oximetry did detect a child who might not have been detected otherwise but failed to detect one that should have been detected.