Pulse oximetry screening for critical congenital heart disease (CCHD)

What is critical congenital heart disease (CCHD)?

Congenital heart disease (CHD) is defined as a structural abnormality of the heart that is present at birth, which impacts proper and/or optimal blood flow.

More specifically, critical congenital heart disease (CCHD) is a subset of lesions commonly defined as “any potentially life-threatening, duct-dependent heart lesion from which infants either die or require invasive procedures (surgery or cardiac catheterization) in the first 28 days of life,²” although some publications like the CDC extend the definition to include the first year of life.³ 

For more information about CCHD and screening protocol, click here.

Pulse oximetry for critical congenital heart disease (CCHD) screening

It has been shown that pulse oximetry can be cost-effective as a noninvasive method for improving early diagnosis rates of CCHD, especially in low-resource areas. ^{1 10-12}

According to a model-based cost effectiveness analysis comparing pulse oximetry screening to no pulse oximetry screening from the Ontario healthcare payer perspective, pulse oximetry screening yielded an incremental cost effectiveness ratio of CAD$1,110.79 per quality-adjusted life months. This was well below the predetermined threshold of CAD$4,166.67. ^8†  

According to a prospective analysis of costs and cost effectiveness of pulse oximetry screening on 100,000 newborns in the Dutch perinatal care setting. Pulse oximetry screening yielded an incremental cost-effectiveness ratio of €139,000 per additional newborn with CCHD. There was a willingness to pay threshold placed at €20,000 per gained quality adjusted life year.^9‡

Neonates with an abnormal pulse oximetry screening are 5.5 times more likely to have CCHD compared to those with a normal screening.¹³ Additionally, late diagnosis of CCHD is associated with higher rates of hospital admissions and inpatient costs during the first year of life.¹⁸ According to a retrospective assessment of states that mandated universal pulse oximetry, there was a 33% decline in early infant CCHD related events after the mandate began.¹⁴

Despite the rise of antenatal detection over the years, there remains great variation in detection rates for this method based on location, technology, skill of technician, and screening protocol.^{1 4 15 16} Even in settings with high antenatal detection, pulse oximetry screening can be beneficial in identifying previously undiagnosed patients with CCHD.^{7 12 17 18}

False-positive cases of pulse oximetry screening have been noted to require medical intervention for non-CCHD related conditions and may be important secondary targets of pulse oximetry screening, especially in low-resource settings.^{5 10 11 19}

Pulse oximetry screening in the NICU is feasible and can be effective at detecting unrecognized CCHD in neonates.^20-22
 

Recommendations for pulse oximetry screening

There are several recommendations for screening practices and protocols for CCHD, with numerous protocols used across studies. The main factors for screening, which are influenced by local needs and limitations, include:

1. Timing of pulse oximetry: Screening prior to 24 hours of age has been shown to increase false positive rates.⁶ However, some healthcare systems have high rates of early discharge (prior to 24 hours), necessitating earlier screening.^{12 23}
2. Probe location^§: Probe placement on the right hand (preductal) and either foot (post ductal) allows for screening of lesions where the difference between the readings is greater than expected, indicating ineffective blood flow.²⁴ Use of two probes increases the cost and time of each test, which may be a barrier in some settings.
   
3. Blood oxygen saturation: Cut-off values for a positive screen vary across studies and recommendations.^{23 25-27} Currently, most screening protocols (with slight variations) consider a positive screen as:
   • Blood oxygen saturation less than or equal to 95%, and/or;
   • Difference in pre- and post-ductal measures greater than or equal to 2–3%
   • With 2−3 repeat measures taken 1−2 hours apart
     

The type of CCHD lesion influences pulse oximetry values and the sensitivity of pulse oximetry, with certain lesions being more detectable than others.^{18 24 28 29}
 

Pulse oximeter selection for CCHD screening

Recommendations for pulse oximetry screening of CCHD advise measurements should be obtained using motion-tolerant sensors that can measure in low-perfusion settings.^{6 23 25 31 32} No specific pulse oximeter brand is mentioned in official recommendation statements for CCHD screening.

Nellcor™ Bedside Respiratory Patient Monitoring Systems meet all pulse oximeter criteria for CCHD screening outlined by the AAP guidelines (Figure 1) ²⁵ as well as those put forth by the European Consensus Group²³ and the Canadian Pediatric Cardiology Association.³⁰

1. Motion-tolerant technology 
   1. Nellcor™ pulse oximetry demonstrates motion tolerance in a variety of settings ^{12 33 34}
2. Tested in low-perfusion conditions
   1. Nellcor™ pulse oximetry is appropriate for low perfusion settings, as seen in newborns, with successful use in neonates according to several recent studies^34-36
   2. In addition to providing accurate measurements (±2) in the standard range of 70%−100% SpO₂, the LoSat capability of Nellcor™ technology allows for accurate measurements (±3) in the lower range of 60%−80%³⁷
3. FDA 510(k) clearance
   1.  The Nellcor™ pulse oximeter has FDA 510(k) clearance (K123581) as a motion-tolerant pulse oximeter and is also compliant with ISO 80601-2-61:2011
4. 2% root-mean-square accuracy
   1. Root-mean-square for SpO2 is under the 2% recommended cutoff for CCHD screening, even during motion³³

One recent clinical study showed that Nellcor™ pulse oximetry demonstrates faster time to post than Masimo Signal Extraction Technology™* (SET™*). A prospective single site study of 60 newborns delivered via Cesarean-section showed³⁴:

• Time to stable oximeter signal was 12 seconds faster on average when using Nellcor™ pulse oximetry compared to Masimo Signal Extraction Technology™* (SET™*)
• A stable oximeter signal was achieved in 100% of patients with Nellcor™ pulse oximetry but only 92% of patients when using Masimo Signal Extraction Technology™* (SET™*).

It is important to note that pulse oximetry accuracy depends on certain human factors, such as probe placement, highlighting the need for complete and regular clinician training.^{11 39}

Adhesive sensors on pulse oximeters may pose a risk for skin trauma, especially to the fragile skin of a newborn.³⁸ The Nellcor™ OxySoft™ sensor’s adhesive helps enable easy removal without the skin stripping that can cause pain and secondary trauma to fragile, delicate or thin skin. Nellcor™ OxySoft™ SpO₂ sensor with a new silicone adhesive, lower profile, and flexible circuit — so it: 
-       removes 87% less skin cells from fragile skin⁴⁰
-       stays in place to keep up with those little wiggles
 

More about CCHD and pulse oximetry screening

To learn more about critical congenital heart disease (CCHD), read more on our blog here or review the findings in full in our whitepaper summarizing the clinical evidence in CCHD.

To learn more about how Nellcor™ pulse oximetry can help in CCHD screening, read more on our website.
 

The Nellcor™ pulse oximetry monitoring system should not be used as the sole basis for diagnosis or therapy and is intended only as an adjunct in patient assessment.