Taking the Pulse of Neonatal Screening for Critical Congenital Heart Disease (CCHD)
Universal screening for critical congenital heart disease (CCHD) using pulse oximetry is becoming the standard of care for newborns in the United States. In 2012, the U.S. Department of Health and Human Services (HHS) endorsed recommendations from the Secretary’s Advisory Committee on Heritable Disorders in Newborns and Children (SACHDNC) to add CCHD to the Recommended Uniform Screening Panel, an established public health tool used to detect a range of heritable disorders.1
Individual hospitals and birthing facilities will be responsible for implementing CCHD screening programs based on national recommendations and, in many cases, new state-level legislation.
Taking the Pulse of Neonatal Screening for Critical Congenital Heart Disease is a three-part educational activity designed to facilitate the implementation of screening for CCHD in newborns. The first two articles described the burden of CCHD, introduced screening for CCHD using pulse oximetry as an effective strategy for improving detection, and summarized current guideline recommendations for universal CCHD screening.
The final article examines improved pulse-oximetry standards that translate into more sensitive screening. The article also looks ahead to the future of CCHD screening with case studies of individual states that have started to implement programs.
Screening for CCHD using pulse oximetry
In the United States, approximately 1.3 infants per 1,000 live births will be affected by CCHD, a type of cardiac defect in which surgical or catheter interventional therapy within the first year of life is mandatory to achieve survival.2 Early detection and follow-up are critical for preventing the morbidity and mortality associated with CCHD.
Detection is challenging, however, due to the subtlety of clinical presentation. For instance, half of all newborns with CCHD, particularly those with ductal-dependent defects, have no distinctive murmur, and in many cases the symptoms of CCHD do not present until after hospital discharge.2,3 CCHD is missed in 1 in 3 affected newborns; missed cases are at an increased risk of life-threatening complications.4
Pulse oximetry is a simple, noninvasive, painless test that can detect mild hypoxemia, a feature of many forms of CCHD that is easy to miss on physical examination.5 As an adjunct to the standard newborn physical examination, pulse oximetry can identify cases of CCHD that escape routine clinical diagnosis.
The current approach to universal screening for CCHD using pulse oximetry reflects the efforts of multiple agencies and collaborative groups, including the American Academy of Pediatrics (AAP), the American Heart Association, and the SACHDNC. Key features of the screening recommendations are outlined in Table 1.
Table 1. Key recommendations forpulse-oximetry screening
|Screen healthy newborn infants|
|Screen at 24-48 hours of life, or as late as possible if earlier discharge is planned|
Obtain oxygen saturation readings in the right hand and one foot
|Exclude CCHD with a diagnostic echocardiogram in infants with positive screening results and no infectious or pulmonary causes of hypoxemia.|
|Source: Kemper AR, et al. Pediatrics. 2011;128:e1259-e1267.|
Evolution of pulse-oximetry standards
Individual hospitals, birthing centers, and other facilities are responsible for selecting appropriate equipment for screening. In practice, implementing pulse oximetry as a screening tool has been fraught with complexities due to the lack of standardization of pulse-oximetry technologies and other standards across hospital settings.
Historically, commercially available pulse oximeters have been labeled by manufacturers according to generation of technology (e.g. “next generation”), yet this designation has not been standardized and may not correlate with test validity or reliability.
In 2011, the SACHDNC, which assembled an independent group of experts in the area of CCHD screening in an advisory capacity, published technological standards for pulse-oximetry equipment to ensure reliable and reproducible outcomes with devices available at the time.1
In 2012, those standards were updated through the issuance of a Food and Drug Administration (FDA) guidance document that addresses devices currently in use.6 (Table 2)
Table 2. Device standards for CCHD screening
|Pulse oximeters used for CCHD screening should comply with the following standards:|
|Indicated for use in motion and non-motion conditions*|
|Reports functional oxygen saturation†|
|Validated in low-perfusion conditions†|
|Cleared by the FDA for use in newborns†|
|2% root mean-square accuracy†|
|Must be calibrated regularly based on manufacturer guidelines†|
|*U.S. Food and Drug Administration.; †Kemper AR, et al. Pediatrics. 2011;128:e1259-e1267.|
The historical context and evolution of technological standards in pulse oximetry are described below. Concern over motion artifact with early pulse oximetry, for instance, prompted the development of motion-tolerant devices, which were recognized as the standard of care in the 2011 SACHDNC guidelines.1 With additional advances in hardware and software, the technological standards for pulse oximetry are expected to continuously evolve.
Looking ahead: future device technology
Technological standards for pulse oximetry are rapidly advancing. In 2011, the HHS endorsed the SACHDNC standards for pulse-oximetry screening, including the recommendation to utilize motion-tolerant devices.7In 2012, the AAP published a policy statement to guide the implementation of these technological standards in clinical practice.8
In addition, several states have passed CCHD screening legislation and implemented CCHD screening protocols based on the SACHDNC technological standards,9-12 and other states have legislation pending.12 Future guidelines from experts will reflect evolving standards of care in CCHD screening using pulse oximetry, including updated standards for device technology.
For instance, all new devices are expected to meet federal performance standards (e.g., sensitivity and specificity for CCHD), regardless of their designation regarding motion tolerance. The FDA, through the issuance of the guidance document, has endorsed the use of all oximetry equipment for CCHD screening that is approved for neonatal patients.6 The adoption of new standards into universal newborn screening protocols will require collaborative efforts from states, hospitals, and health-care providers.
Standardizing screening protocols
Based on national guidance and state legislation, hospitals and birthing centers will be required to implement CCHD screening programs. The particular screening strategy should reflect the conditions within each particular facility, as well as the needs of infants, families, and the health-care providers. On a practical level, caregivers should understand the requirements related to sensor type and placement.