What is the pH of the umbilical cord?
The median umbilical cord arterial pH was 7.22; range 6.55–7.52; interquartile range 7.17–7.27.
What are cord blood gases for?
Cord blood gas analysis is an objective measure of the fetal metabolic condition at the time of delivery. By determining fetal acid-base status, it helps identify infants at risk for neonatal encephalopathy.
How do you read the pH of a cord?
The reference range for arterial cord blood pH is 7.12-7.35, and for arterial cord BD it is +9.3 to –1.5 mmol/L. In obstetrics, significant metabolic acidosis is often defined as cord arterial blood pH <7.0 and BD >12.0 mmol/L. Some institutions have adopted a higher pH threshold of <7.1.
How do you take the ABG from the umbilical cord?
Insert the needle into the umbilical vein slowly at a 45-degree angle. Be careful to avoid going completely through the vein. The syringe is self filling, allow it to fill with blood. Obtain the required amount of blood according to hospital policy between 0.5 & 1ml and remove the needle from the umbilical cord.
Which infant is most at risk for hypothermia?
Neonates, particularly very low-birth-weight infants, are susceptible to environmental hypothermia; illness (eg, intracranial hemorrhage, sepsis) increases risk.
When should you take cord blood gases?
Umbilical cord blood gas analysis is recommended by NICE whenever there has been a concern about the baby either in labour or immediately following birth.
What do umbilical cord gases mean?
If pH is low, the baby’s blood is acidic, which means that at birth, the baby had an elevated PCO2 and/or an increased number of acidic by-products (mainly lactic acid) caused by anaerobic metabolism. In general, an elevated PCO2 means that the fetus is producing more CO2 than can be eliminated through circulation.
What is a normal cord blood pH?
Normal arterial cord blood gases for a term newborn: pH: 7.18 – 7.38. PCO2: 32 – 66 (mmHg)
How do you read base excess?
While carbon dioxide defines the respiratory component of acid–base balance, base excess defines the metabolic component. Accordingly, measurement of base excess is defined, under a standardized pressure of carbon dioxide, by titrating back to a standardized blood pH of 7.40….
How do you obtain cord gas?
The standard technique of sampling cord blood for gas and acid-base analysis comprises three steps:
- clamping a segment of the cord.
- removing the clamped cord segment.
- needle aspiration of two blood samples (one venous, one arterial) from the excised clamped cord segment into preheparinized syringes.
How do you take a cord blood sample?
Right after the birth of your baby, the umbilical cord is clamped and cut. If cord blood is to be drawn, another clamp is placed 8 to 10 inches (20 to 25 centimeters) away from the first. The section between the clamps is cut and a blood sample is collected into a specimen tube.
Why is the umbilical cord used for blood gas analysis?
The pH, base excess and p CO 2 (acid-base status) of arterial blood flowing through the umbilical cord provides valuable objective evidence of the metabolic condition of neonates at the moment of birth; a notion that has assured a role for the blood gas analyzer in hospital delivery suites in cases of suspected fetal distress/asphyxia.
What is the ACOG opinion on umbilical cord blood?
ACOG Committee Opinion No. 348, November 2006: Umbilical cord blood gas and acid-base analysis Umbilical cord blood gas and acid-base assessment are the most objective determinations of the fetal metabolic condition at the moment of birth.
How does cord compression affect umbilical venous acid base?
Consequently, there is more carbon dioxide eliminated through the umbilical arteries, which renders the arterial cord blood more acidotic, while the umbilical venous acid-base status remains equilibrated by the normally functioning placenta. The severity of cord compression has a significant effect on the arteriovenous pH difference.
What is metabolic acidosis in umbilical cord blood?
Significant metabolic acidosis, widely defined as cord arterial blood pH <7.0 and base excess <–12.0 mmol/L (base deficit >12.0 mmol/L), occurs in around 0.5-1 % of deliveries.