A global shortage of foetal scalp electrodes could reduce access to internal heart rate monitoring, potentially leading to more perinatal deaths and other complications, ob/gyns in Canada have warned, after a Philips recall of 1.7m of the devices that attach to babies’ scalps for monitoring inside the womb.
The company had notified users in November 2022 that there was a risk of the electrodes’ tips breaking off and potentially requiring surgery for removal, reports Medscape Medical News.
In the American Journal of Obstetrics & Gynecology Maternal-Foetal Medicine, Daniel Kiely, MDCM, MSc, of the University of Montreal and Dr Lawrence Oppenheimer of the University of Ottawa wrote that although the recall is “presumably intended to improve safety, the resulting shortage poses risks to patients due to inadequate foetal heart rate monitoring”.
They described the electrodes as “a critical tool in ensuring a consistently interpretable tracing of the foetal heart rate” when high-quality tracing isn’t possible by monitoring externally with transducers attached to the pregnant woman’s abdomen.
With external monitoring, a consistent signal may not be obtainable, particularly in patients with elevated body mass index or who are in the second stage of labour, they wrote.
External monitoring can also mistakenly detect a maternal pulse, or another foetal pulse in the case of multiple pregnancies. Accurate tracing might not be attainable even after repositioning transducers and applying a maternal pulse oximeter, yet a bad reading may appear correct due to technology that “smooths out” the signal when it jumps from one source to another, said the researchers.
Signal ambiguity can mask an abnormal foetal heart rate or even foetal death, and is linked to intrapartum foetal hypoxic ischaemic encephalopathy, or loss of blood flow to the brain; stillbirth; neonatal death; and unnecessary Caesarean delivery for already stillborn foetuses.
ECRI, an independent, non-profit patient safety organisation, sent an alert to its 3 000 members, which include many hospitals, on 27 April warning that the electrode shortages could lead to higher rates of elective Caesarean deliveries.
The alert said that Cardinal Health, the only US supplier of electrodes compatible with Philips’ foetal heart rate monitors, has reported supply problems and does not anticipate having stock until August.
According to the ECRI alert, the US Food and Drug Administration (FDA) determined that given the supply issues, Philips could distribute some of its recalled electrodes on the basis of clinical need. It said that Philips had had “less than 30 reports” of tip failures that required surgical intervention.
Lisa Black, media relations manager for the American Academy of Paediatrics, said she could not locate anyone in her organisation who was familiar with the problem.
Kiely and Oppenheimer co-wrote a protocol that recommends internal monitoring as the preferred response when clinicians suspect signal ambiguity, with ultrasound being a last resort.
They noted that Philips had, in 2009, advised internal monitoring as a backup as it warned about signal ambiguity in a recall of its foetal heart rate monitors.
“Given that Philips monitors are in use worldwide,” they wrote, the current electrode recall “is undermining the solution to a previous recall”.
In response, Philips told Medscape it had become aware of low availability of products “comparable to the Foetal Spiral Electrode that until recently had been supplied from other manufacturers, following the November 2022 recall and discontinuance by Philips”.
“We are aware that the current shortage of compatible products is due to a number of factors, including supply chain issues, and are in discussions with stakeholders regarding whether Philips may potentially contribute to addressing this issue for health care providers with urgent clinical needs.”
The company said that at the time of the recall notification, “Philips analysis indicated an observed incidence rate of less than 0.01% of device uses of this type, with no reports of patient death related to this issue”.
Medscape article – Shortage of Scalp Electrodes May Harm Foetuses, Clinicians Warn (Open access)
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