At birth, a 10- to 20-cm segment of umbilical cord is doubly clamped and cut. Edelstone DI, Peticca BB, Goldblum LJ. Unlike other blood samples obtained through a vein, a blood sample from an . HCO 3 - is a base, which helps mop up acids (H+ ions). Blood is sampled into a preheparinized syringe by needle aspiration. This smartphone app focuses on the preanalytical phase of blood gas testing and what operators can do to avoid errors. This so-called hidden acidosis phenomenon is thought to be a transient physiological effect of initiation of neonatal breathing [13] and can give a false impression of significant acidosis at birth. Martin GC, Green RS, Holtzman IR. 2016, Medications. Specs: Laminated 8.5 X 11 inches (21.6 X 27.9 cm) ISBN: 978-1-937967-06-2 Item No: 3rd Ed Nomo Add to cart Arch, Duerbeck N, Chaffin D, Seeds J. Benirschke and Kaufman (10) have observed that cord compression (presumably cord occlusion followed by terminal fetal bradycardia) leads to congestion in the terminal capillaries and an increase in villous blood volume, sometimes by more than 50%. Show more Show more Shop the RegisteredNurseRN store Lab Values. Acidosis usually presents itself as decreased blood pH and increased base deficit. Which interpretation of these umbilical cord and initial neonatal blood results is correct? The umbilical vein is more easily compressed than the umbilical arteries because it has a thinner muscular wall, and the mean blood pressure in the vein (5) is lower than that in the arteries (6) by a factor of approximately ten. Blood gas interpretation for neonates Blood gas interpretation for neonates Key messages Blood gases are helpful to assess the effectiveness of ventilation, circulation and perfusion. Anion Gap - 12 24-HCO. First, the A-V difference of lactate in cord blood has not been sufficiently clearly defined, so there is no way of reliably confirming that a lactate result relates to cord arterial blood. This paper discusses considerations for interpretation of blood gases in the newborn period. 60 minutes. The pH, base excess and pCO2 (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. Our specific aim was to develop a standardized clinical care pathway, ensuring timely identification and evaluation of neonates with umbilical-cord acidemia at risk for HIE.METHODS. Unfortunately it is more difficult to sample arterial than venous cord blood because umbilical arteries are much smaller and less visible than umbilical veins [20]. It is used to determine the extent of the compensation by the buffer system and includes the measurements of the acidity (pH), levels of oxygen, and carbon dioxide in arterial blood. 1. When she inhales, she picks up oxygen into her blood that is carried to the placenta and fetus. New York, Springer-Verlag; 1990, p91. Benefits of introducing universal cord blood gas and lactate analysis into an obstetric unit. An arterial blood gas is a laboratory test to monitor the patient's acid-base balance. For many years it has been standard obstetric practice to clamp the umbilical cord within seconds of birth, a policy that is, as discussed above, coincidentally fortuitous for the most accurate assessment of neonatal acid-base status. Second, there remains no consensus on the cut-off lactate value that should be used to define significant cord metabolic acidosis, as there is for pH and base excess (pH <7.0, base excess. Umbilical cord blood gas sampling is the most objective determinant of fetal metabolic condition at the moment of birth. So, the umbilical cord contains three blood vessels: one large vein carrying oxygenated blood to the fetus and two much smaller arteries carrying deoxygenated blood that is relatively rich in carbon dioxide and other metabolic waste products from the fetus. Likewise, any umbilical venoarterial PCO2 difference of greater than 18 mmHg also is associated with either cord occlusion with terminal fetal bradycardia or chronic fetal heart failure with terminal fetal bradycardia. So long as these minimum differences in pH and pCO2 between the two samples are evident, it can be assumed that the two samples came from different vessels, and that the one with lowest pH and highest pCO2 came from an artery (Table I). Based on the Siggard-Andersen Acid-Base Alignment Nomogram, this handy chart allows you to comfortably interpret a neonatal blood gas result in seconds. Membranes ruptured spontaneously two hours prior to admission. They quite literally worked as hard as if not harder than the doctors to save our lives. Br J of Obstetrics and Gynaecology 1994; 101: 1054-63, Riley R, Johnson J. The results of the analysis can show how healthy the baby is and determine if they have a birth injury. If a baby suffered from hypoxia that resulted in a birth injury, the blood cord gases can prove the legitimacy of the plaintiff's claim. Expel all air bubbles. Calcium Equivalents. Both forms of acidosis can cause neurological issues that can be temporary or permanent depending on how severe the damage is. The effect of this inconsistency in determining cord-blood base excess has recently been demonstrated [33]. Johnson JWC, Richards DS. The blood-gas values were statistically analyzed and reported. Correpondence of this manuscript should be addressed to: Case 10: Umbilical Cord Occlusion with Terminal Fetal Bradycardia, Mild. 2001-2023 BabyMed.com - All Rights Reserved. Base excess is defined as the amount of strong acid that must be added to each liter of fully oxygenated blood to return the pH to 7.40 at a temperature of 37C and a pCO2 of 40 mmHg (5.3 kPa), while a base deficit (ie. Table II lists some of the factors that may adversely affect fetal oxygenation and contribute to or cause fetal hypoxia and consequent cord-blood metabolic acidosis. Nippon Sanka Fujinka Gakkai Zasshi 1984;36:1921-9. a man of no importance: love who you love; imc graduate trader interview questions; gretchen bakery brownie recipe; north ga road conditions; cord gas interpretation calculator. Instead, the exchange of gases, breathing occurs in the placenta where oxygen is transported from the mother's blood vessels into the placenta and then from the placenta through the umbilical cord to the fetus and carbon dioxide is exchanged from the fetus to the mother. The authors declared no conflict of interest related to work presented in this manuscript. On your arrival, the patient appears drowsy and is on 10L of oxygen via a mask. Efficacy depends on initiating this hypothermic treatment within 6 hours of birth. pH is a measure of acidity or alkalinity of any solution. Menu vscode compare with clipboard. However, doctors can also use blood cord gases to defend birth injury lawsuits as well. In short, significant cord metabolic acidosis (pH <7.0 and base excess, Currently, the only effective treatment for HIE is controlled cooling of the baby to a rectal temperature of 34 0.5 C for 48-72 hours. 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 This test measures the partial levels of these substances using a small blood sample. On the other hand, blood in the two umbilical arteries reflects the fetal status. A fetus relies on the mother for oxygen and carbon dioxide exchange. This is why the cord must be clamped quickly. Assuming a normal distribution of differences between umbilical venous and arterial pH, the upper limit of the 95th percentile range is 0.10 (see Case 5). To understand what cord blood gases are, it's helpful to know how the placenta supplies oxygen and nutrition to a baby in the womb. Finally, the potential role of cord-blood lactate measurement will be discussed. Likewise, there will also be a greater associated fetal hypovolemia. The policy of delayed cord clamping clearly poses a potential problem for accurate assessment of neonatal acid-base status at birth, because of the hidden acidosis phenomenon. FO . Prior to total cord occlusion, there may be a brief period of slowed umbilical venous blood flow. From an obstetrics perspective, these can be challenging to really interpret, but the simple interpretation is often worth some CREOG points if you can analyze these systematically. (Note that umbilical venous blood gas values more closely resemble those of adult arterial blood than do those of umbilical arterial blood. It is a red flag that indicates the presence of hypoxia during delivery. The test is used to check the function of the patient's lungs and how well they are able to move oxygen into the blood and remove carbon dioxide. Fetal and maternal circulation is proximate at the placenta where gas/nutrient exchange between maternal and fetal circulation occurs. Early Human Development 2010; 86: 336-44, Kurinczuk J, White-Koning M, Badawi N. Epidemiology of neonatal encephalopathy and hypoxic-ischemic encephalopathy. Normal Arterial Blood Gas Values pH : 7.36-7.44 PaCO2 : 36-44 mm Hg HCO3 : 22-26 mEq/L Legal Notices and Disclaimer All Information contained in and produced by the Pediatric Oncall system is provided for educational purposes only. To obtain a sample of umbilical cord blood, a 10-20 cm section of the umbilical cord is double-clamped and put on ice. The validation of paired (arterial and venous) samples is based on minimum arterio-venous (A-V) differences for pH and pCO2 experimentally determined by Westgate et al [2]. When this occurs, one should expect a higher PO. If umbilical artery blood is abnormal, then causes should be considered. Am J Obstet Gynecol 1997;177:274-81. Clearly, PO2 is not always elevated following cord occlusion with terminal bradycardia. Arch Dis Child Fetal Neonatal 2007; American College of Obstetricians and Gynecologists Committee on Obstetric Practice. In Geneva in 1821, a French nobleman Jacques Alexandre Le Jumeau, Vicomte de Kergaradec, became the Apgar scores and umbilical artery pH have traditionally been used as objective measures of 2022 Radiometer Medical ApS | kandevej 21 | DK-2700 | Brnshj | Denmark | Phone +45 3827 3827 | CVR no. Curr Opin Obstet Gynecol 2001; 13: 141-45, Gjerris A, Staer-Jensen J, Jorgenson J. Umbilical cord blood lactate: a valuable tool in the assessment of fetal metabolic acidosis. Jeffrey Pomerance MD MPH is the sole contributor to this Educational Series article. What is the pH (and what do we accept in newborns)? Normal values of umbilical arterial samples in a preterm newborn: *The P in PCO2 and PO2 stands for partial pressure, which is how these umbilical cord blood gases are measured. a) Contamination of the arterial sample with an air bubble resulting . Input pH : Input pCO 2 : HCO 3 = Base Excess = . They explain that the information gained from a blood gas assessment of the umbilical cord (done in conjunction with other testing such as placental histology) will not only assist clinicians with diagnosis and counseling of the parents, it can also provide a defense in case of a lawsuit. Cord-blood metabolic acidosis which is characterized by reduced blood pH and decreased base excess (i.e. Umbilical cord blood gas analysis helps doctors can detect if the child suffered a birth injury during delivery. - SLE Meanwhile, the fetus is being deprived of its only supply of oxygen and has a gradually decreasing blood volume. Obstet Gynecol 1992; 79: 959-62. (3,4) Finding a pH difference greater than 0.10 suggests either cord occlusion with terminal bradycardia or chronic fetal heart failure with terminal bradycardia. A difference between umbilical venous and arterial pHs greater than 0.10 is suggestive of cord occlusion with terminal bradycardia. 16,17 Current cord blood gas reference ranges were defined when early cord clamping at less than 30 seconds was routinely practiced. Abnormal cord blood gas results are a marker for a birth injury. Volume expansion is encouraged as part of advanced neonatal resuscitation if more basic care does not result in the desired improvement. Arterial Blood Gas (ABG) Analyzer - MDCalc Arterial Blood Gas (ABG) Analyzer Interprets ABG. Then it can be seen that bicarbonate "falls," revealing the underlying . PCO2 measures the amount of carbon dioxide gas dissolved in the blood, and PO2 measures how much oxygen is in the blood. Since acid-base status is in flux during the perinatal period, the timing of isolating a sample for analysis is crucial. In addition to his current work, Dr. Amos is using his vast experience to launch Obie, a science-based app that offers personalized fertility advice. Anion Gap = Na - (HCO + Cl) Gap-Gap Ratio =. The hallmark of cord occlusion with terminal bradycardia is widened venoarterial pH, PCO. The interpretation of blood cord gas levels can also be used by malpractice lawyers and medical experts to show the severity of damage that occurred during delivery by citing the specific pH and base deficit levels. Arterial blood gas analysers are designed to measure multiple components in the arterial blood. TABLE I: Median and centile ranges for umbilical-cord blood gas and lactate values [1]. Well summarized and easy to under stand and remember . It follows, theoretically at least, that arterial cord-blood lactate concentration should be as reliable an indicator of birth asphyxia and risk of HIE as the more established tests, arterial cord-blood pH and base excess. Metabolic acidosis develops because when tissue cells are severely depleted of oxygen, aerobic metabolism of glucose is compromised, and cells must depend for their function and survival on less effective anaerobic pathways that result in reduced ATP (energy) production and, importantly for this discussion, accumulation of metabolic acids (principally lactic acid) [6]. Reduced prevalence of metabolic acidosis at birth: an analysis of established STAN usage in the total population of deliveries in a Swedish district hospital. The American College of Obstetricians and Gynecologists (ACOG) also favor a selective approach, stating that cord-blood testing should be applied in the following situations [22]: The Society of Obstetricians and Gynecologists of Canada (SOGC), by contrast, recommend that cord blood gas analysis be performed at all births [7]. The last case I referred to them settled for $1.2 million. Scenario 1. What's the diffe. Wong L, MacLennan A. The design of this study depended on the policy of universal cord blood gas testing that had been adopted in the obstetric unit where the study was conducted. Acidosis has two different types: respiratory acidosis and metabolic acidosis. An ABG calculator is a tool that provides an easy way to determine the acid-base status by inputting the pH, PaCO2, and HCO3- values. Umbilical cord O 2 and CO 2 Fetal cord gas values result from the rapid transfer of gases and the slow clearance of acid across the placenta. It is these values that describe the baby's metabolic state. Pediatrics 1997; 99: 851-59, Peliowski-Davidovich A. Hypothermia for newborns with hypoxic ischemic encephalopathy. There are also blood cord gas interpretation errors that inflate or deflate the child's hypoxia at birth. When HCO 3 - is low the pH is decreased as there are more free H+ ions (acidosis). For pH, the A-V difference should be >0.02 pH units, and for pCO2 the A-V difference should be >0.5 kPa (3.75 mmHg). An arterial blood gas (ABG) is a test that measures the oxygen tension (PaO 2 ), carbon dioxide tension (PaCO 2 ), acidity (pH), oxyhemoglobin saturation (SaO 2 ), and bicarbonate (HCO 3) concentration in arterial blood. Mean PCO2 (carbon dioxide): 49.9 14.2 (mmHg). Maternal reduced oxygen-carrying capability due to: - anemia Since the incidence of HIE is much lower (around 1.5/1000 live births [10]) than that of significant metabolic acidosis (0.5-1 % live births [1]), it is clear that HIE is not an inevitable consequence of significant metabolic acidosis. (17) However, there is no clear evidence that volume expansion is helpful in neonatal asphyxia. Terminology and normal arterial blood gases . The article begins with some background physiology/anatomy of placental/fetal circulation that highlights the all-important distinction between arterial and venous cord blood for accurate assessment of fetal/neonatal acid-base status. The levels determine if the baby has acidosis, a condition caused by the overproduction of acid in the blood. Early Human Development 2014; 90: 523-25, National Institute for Health and Care Excellence (NICE). Basal Energy Exp. NEONATOLOGYTODAY Volume 15Issue 11 Pages 54-57 Release date: November 2020 DOI: https://doi.org/10.51362/neonatology.today/20201115115457 [Click Here to Download PDF], [Full Text][Figures & Tables][Article Info][Reference]. WARNING. ROME method for ABGs (arterial blood gases) interpretation: Solve uncompensated, partially and fully compensated ABG problems. Obstet & Gynecol 2010; 1(9): WMC00694, Mokorami P, Miberg N, Olofsson P. An overlooked aspect on metabolic acidosis at birth: blood gas analyzers calculate base deficit differently. Arch Dis Child 1988;63:570-1. Br J of Obstetrics and Gynaecology 1993; 36: 13-23, Low J. Intrapartum fetal asphyxia: definition, diagnosis and classification. Info | This calculator provides all the parameters derived from Stewart's theory of acid-base balance. Asphyxia is reduced tissue oxygen (hypoxia) of sufficient severity and duration to cause metabolic acidosis [5]. So when HCO 3 - is raised the pH is increased as there are less free H+ ions (alkalosis). The finding of isolated respiratory acidosis (i.e. White C, Doherty D, Henderson J et al. Cord Blood Gas Results | What You Need to Know. The umbilical cord was tight around the shoulder and body. Experimental design in psychological research, 4th ed. It was a good review of ABG analysis. The severe intrapartum hypoxia that this degree of cord metabolic acidosis reflects is associated with increased risk of hypoxic brain-cell injury and associated hypoxic-ischemic encephalopathy (HIE). 7.35-7.45. pH < 7.35 indicates ACIDOSIS (ACID) At times, congestion might lead to a decreased efficiency of the transfer of carbon dioxide and oxygen between mother and fetus. Westgate JA, Bennett L, Gunn AJ. In: Handmaker H, Lowenstein JM (eds): Nuclear medicine in clinical pediatrics.. New York, Society of Nuclear Medicine, 1975, pp167-185. May contain information that is not supported by performance and intended use claims of Radiometer's products. Ron even fought to reduce how much I owed in medical bills so I could get an even larger settlement. It is also important to get accurate results. 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 1. . Eur J Obstet Reprod Biol 2012; 162: 21-23, Armstrong L, Stenson B. - diabetes Hopefully I won't need it again but if I do, I have definitely found my lawyer for life and I would definitely recommend this office to anyone! Khazin AF, Hon EH, Yeh SY. Interpreting umbilical cord blood gases and detecting birth asphyxia The most important measurements in a blood gas test for evaluating a baby's current condition and prognosis are the pH and the base deficit. Your body normally tightly regulates the amount of oxygen and carbon dioxide in your . Once terminal fetal bradycardia has begun, the umbilical venous blood flow does not reopen; therefore, the venous sample is usually a reasonable proxy for the infant's acid-base status prior to terminal fetal bradycardia. However, it is important to note that the ABG calculator should not be used as a substitute for clinical judgment. The P o2 and P co2 values can provide further clues to the interpretation of the clinical picture and helps to exclude rogue results. Cord blood P o2 and P co2 The blood gas analyser measures pH, P co2 and P o2 and then calculates base excess after normalising P co2. has a master's degree in medical biochemistry and he has twenty years experience of work in clinical laboratories. To retrieve blood for analysis the cord segment is first cut between the two clamps at each end, so that the clamped segment can be removed from the immediate vicinity of the baby. If the two samples return similar results (i.e. The assessment should take place within 60 minutes. HIE is thus a significant cause of perinatal death and birth-related permanent disability. During labor, the FHR monitor revealed recurrent variable decelerations that were deeper and longer-lasting, and then a deceleration to 60 bpm for three minutes. HCO. Compensation can be seen when both the PCO 2 and HCO 3 rise or fall together to maintain a normal pH. WHY are blood gases so helpful? 2008; 139: 16-20, Koshnow Q, Mongelli M. Cord blood lactate and pH values at term and perinatal outcome: a retrospective cohort study. Although uncommon, the venous sample also may demonstrate significant respiratory and metabolic acidosis. The umbilical cord segment can be set aside at room temperature for 60 minutes without risk of clotting or changes in pH, PO 2, or PCO 2. Delay in clamping may result in significant change in acid-base parameters; the longer the delay, the greater is the change. Analyzing cord blood gases (oxygen O2 and carbon dioxide CO2) from the umbilical artery is believed to be a good representation of the fetal acid-base status immediately before birth. In general, however, metabolic acidosis is associated with more adverse outcomes. Yeomans ER, Hauth JC, Gilstrap LC III, Strickland DM. (18,19) This is difficult to study because of the rarity of delivery room resuscitation that includes volume expansion. Program: Blood Gas Interpretation Chart, 3rd Ed (5-Pack) $ 30.00 Based on the Siggaard-Andersen Acid-Base Alignment Nomogram, this tool allows you to accurately interpret a neonatal blood gas result in seconds. Instructors may supply a dry-erase pen during blood gas instruction . The calculator also determines whether the state is compensated or uncompensated. Can occur after delayed cord clamp. Australia and New Zealand J of Obstetrics and Gynaecology 2010; 50: 318-28, Get fertility advice personalized for you, Umbilical cord base excess or base deficit, needle aspiration of two blood samples (one venous, one arterial) from the excised clamped cord segment into pre-heparinized syringes. Some experts define fetal acidemia as a pH of less than 7.1. Use of umbilical cord blood gas analysis in the assessment of the newborn. If the episodes are severe enough or frequent enough, there may be insufficient time for complete recovery between episodes, and acid-base values will deteriorate over time. Collecting and analyzing cord blood gases. not associated with metabolic acidosis) at birth is indicative of impaired gas exchange and consequent reduced oxygen delivery to the fetus. Wykoff M, Garcia D, Margraf L, Perlman J, et al. [1] Blood gas analysis is a commonly used diagnostic tool to evaluate the partial pressures of gas in blood and acid-base content. The slower the circulation is through the placenta, the greater the amount of oxygen diffusion from mother to fetus, and the higher the PO2 in the umbilical vein. Many children with troubling cord blood gas and APGAR results and have no long-term physical or cognitive deficits. Close. Box 51-1 describes an umbilical cord blood gas sampling procedure. It is vital, therefore, that the acid-base parameters (pH, base excess (BE) and lactate) derived from arterial rather than venous cord blood are used to assess neonatal condition. Indeed, most (around 75 %) babies with significant metabolic acidosis (pH <7.0, base excess. Interpreting Arterial Cord Blood Gas Values. A. The most likely pathophysiology is as follows: Initially, in terminal cord occlusion, both the umbilical vein and the umbilical arteries are occluded. However, because lactic acid crosses the placenta relatively poorly, a significantly greater base deficit in arterial cord blood indicates the presence of umbilical vein occlusion with at least some interval of partially restored umbilical arterial blood flow. Review ABG Interpretation with Cathy! (Clinical guideline 55) 2007, Haken N, Carlsson A. This calculator only differentiates between acute (pH abnormal) and compensated (pH normal). - antiphospholipid syndrome, TABLE II: Factors that may affect fetal oxygenation in labor [7]. 3. "(20) (saline). However, there is an apparent consensus among those who have studied the issue that measurement of cord-blood lactate measurement has potential that should be further investigated. Check out our full ABG interpretation guide if you want to learn more. cord gas interpretation calculator. You perform an ABG, which reveals the following results: PaO2: 7.0 kPa (11-13 kPa) || 52.5 mmHg (82.5 - 97.5 mmHg) pH: 7.29 (7.35 - 7.45) There are many reasons as to why a baby would have normal blood cord gases despite suffering from a hypoxic brain injury. pH : 7.36-7.44. What must you do with the air in the heparinized syringe? Sodium and chloride are required for anion gap calculation. Adult arterial (non-cord) blood values (for comparison only). However, arterial blood can be difficult to obtain due to weak pulses or patient movement. You are asked to review a 63-year-old female who was admitted with shortness of breath. Universally obtained umbilical cord gas values and Apgar scores were extracted. Your doctor may run a blood gas analysis or arterial blood gas (ABG) test if you are showing the signs of an oxygen, carbon dioxide, or pH imbalance such as confusion or difficulty breathing. Immediately after birth, ideally before the babys first breath, an approximate 20-cm segment of the cord must be isolated between two sets of two clamps. The results from cord blood gases are frequently used as evidence in medical malpractice lawsuits by both attorneys and doctors as a marker for the harm done to the child and to prove whether negligence was involved in a child's injury. Observations on fetal heart rate and fetal biochemistry III: Base deficit of umbilical cord blood. Read our ABG Interpretation Guide. Normal arterial blood cord gases values in a full-term newborn: Normal blood cord gases levels in a preterm newborn: All values are 1 standard deviation. The purpose of this test is to analyze the neonate's ventilatory status by measuring the pH and carbon dioxide concentration in the blood. Median and centile ranges for umbilical cord blood gas and lactate values Median (5th-95th percentile) PH:7.27 (7.12 - 7.35) pO2:16.3 mmHg (6.2-27.6); PCO2:55.1 mmHg (41.9-73.5) Bicarbonate:24.3 mmol/L (18.8-28.2) Base excess:-3.00 mmol/L (-9.3 to +1.5) Lactate:3.7 mmol/L (2.0-6.7) In recent years there has been increasing acceptance of the notion that delaying cord clamping by 2-3 minutes after birth is beneficial to the baby because of the placental blood transfusion it permits. Tight nuchal cord and neonatal hypovolemic shock. If cord occlusion occurs intermittently prior to a terminal cord occlusion and bradycardia, as is usually the case, any respiratory or metabolic acidosis in the fetus will likely recover completely between episodes. Because there is more acidic carbon dioxide (CO2) in the venous circulation, this occurs. Umbilical cord blood gases were: pH 6.88, PCO2 114, PO2 10, bicarbonate 15, base excess (-) 20. Venous cord blood analysis reflects a combination of maternal acid-base status and placental function . (21,22) In the current case, the difference in the degree of metabolic acidosis between venous and arterial samples is not great (BD 7 mmol/L versus 11). APGAR Scores; Braden Scale . A widened difference in PCO2 (18 mmHg or greater) in the absence of a widened pH difference is clinically quite rare. Maternal-fetal acid-base physiology. ANZJOG 2011; 51:17-21. Arterial Blood Gas (ABG) Interpretation: Practice Problems, Answers, & Cheatsheet. And what is a normal PC02 level? Cord-blood respiratory acidosis is a relatively common transitory state that resolves soon after birth when the baby starts to breathe; it is of little clinical significance [7, 18]. If is preferable to obtain both arterial and venous umbilical cord blood samples for analysis. The pros and cons of selective versus routine cord blood gas analyses were discussed by Thorp et al [20]; their views are summarized below.
