1: Why Cord Blood Gas Analysis?

Cord blood gas analysis provides the only practical objective measure of the infant's condition at birth, as opposed to the Apgar score which is subjective, usually assigned retrospectively and is influenced by many factors other than hypoxia during labour.

The presence of an arterial metabolic acidosis will identify those infants who have experienced significant oxygen deficit prior to delivery, and who therefore may be at risk of neonatal problems.

Conversely, normal blood gas results can refute any subsequent claim of hypoxic related birth. It is essential in defending litigation.

It encourages a physiologically-based approach to infant assessment - i.e. causes people to THINK about the physiology of what's going on during birth and helps them to retrospectively review the fetal heart rate trace during labour.

It is useful information to have when counselling parents of babies who encounter problems in the neonatal period. It provides an objective tool for the audit of care during birth - i.e. the number of babies born with a metabolic acidosis can be used as a quality standard of care.

An outcome measure is needed that can reliably reflect the condition of the infant at birth and provide an indication of the level of oxygen deprivation actually sustained during labour. This information is essential to audit care from the infant's viewpoint.

2: What is Expert DataCare?

Expert DataCare is a PC software package that connects to all popular blood gas analysers (Bayer, Chiron, Radiometer, Instrumentation Laboratory, AVL). Expert DataCare first interprets the data from the blood gas machine. It will confirm that both an arterial and venous sample have been obtained. If not it will advise re-sampling.

3: Printed Report

Expert DataCare will print out a sticky label with the cord blood gas results and its interpretations for conclusion in the mother's reports and baby's notes.

4: The Quality of Data without DataCare

To be of any value, one must obtain a blood sample from both the cord artery and vein. However, the artery can be quite difficult to sample. If there is no mechanism to check the results at the time of sampling then often two vein samples are obtained instead of an artery and a vein pair. A single sample has little clinical value and absolutely no value in a court of law.

When we reviewed data from a multicentre trial in the UK and Europe where DataCare had not been used, it was found that only 40% of cases had both successful artery and vein samples. With a success rate this low it is hardly worth bothering to do cord blood gas analysis.

Expert DataCare ensures Quality Data
In units where Expert DataCare is used, the success rate in obtaining true paired results can be greater than 90%.

5: How does Expert DataCare work?

Recognition of sampling errors
Expert DataCare has in built expert knowledge to enable it to recognise when an erroneous sample has been obtained. Sample errors are flagged up at the time of sampling to enable an opportunity to obtain a better quality sample.

Physiological errors cannot be detected by the blood gas analyser - they can only be detected by Expert DataCare.

Physiological error ranges have been identified based on our experience of using cord blood gases in many thousands of cases.

Expert interpretation of results
Acid-base balance is a difficult area and this is particularly so for umbilical cord acid-base measurements. The system uses the experience and knowledge of physiologists, obstetricians and pediatricians to interpret the results and identify infants who may experience problems in the neonatal period.

The validated results are interpreted using a database of rules and classified into one of 36 groups ranging from all results normal to severe arterial and venous metabolic acidosis. A full and summarised explanation of the results is given.

Expert DataCare interfaces to all popular cord blood gas analysers.
This includes Bayer (formally Chiron and Ciba Corning), Radiometer, Instrumentation Laboratory and AVL.

6a: What are the Practical Aspects? Which Vessel should we sample?

Both. Without both artery and vein samples you cannot be sure that you have the artery. It is the artery that reflects fetal acid-base balance but is more difficult to get. A single sample cannot be guaranteed to have come from the artery and so is of no value for audit or in a court of law.

6b: What are the Practical Aspects? Which deliveries should get cord blood sampling?

All deliveries. If you do cord blood gas analysis for audit purposes then you clearly need to know about your whole population of births, not just a sub-group. If you do cord blood gas analysis for defence against subsequent litigation then again, you need to do all births because there is no way of telling which cases might bring about a future claim. Some have suggested just doing sampling on cases with Apgars less than 7 at five minutes. The problem here is that Apgars are so subjective that they are easily challenged in a court. The only way to exclude intrapartum events as a cause of cerebral palsy and block litigation is to have the cord blood gas data from a validated paired sample.

6c: What are the Practical Aspects? Who should do cord blood gas analysis?

Anyone can be trained to get reliable cord blood gas results. In Plymouth our nursing auxiliaries take almost all samples. We have measured their performance and have found that they consistently achieve higher success rates in obtaining paired samples than either midwives or doctors. The important factor is the provision of good quality training so that staff are aware of the potential pitfalls in cord blood sampling.

7: What is included in the service contract?

Training
We will provide all units with 1 day's training on the software and on the operational aspects of adopting routine cord blood gas analysis into your unit.

Software updates
All software updates and updates to the expert system knowledge will be provided free as part of the maintenance contract. We anticipate this to be at least once per annum.

Customer Support
We have midwives working with K2 Medical Systems to provide you with quality customer support. They have in-depth product knowledge of Expert DataCare and much practical experience of cord blood sampling.

Clinical Audit
K2MS will provide a confidential annual report of your units' cord blood gas data.

Every 6 months we will provide you with a clinical audit report that can be used to track changes in clinical performance. You can compare your unit's performance with the previous year and we will also provide you with data from a comparable unit (anonymous)