Did you mean: fetal acidosis
-
American Family Physician Aug 2020Continuous electronic fetal monitoring was developed to screen for signs of hypoxic-ischemic encephalopathy, cerebral palsy, and impending fetal death during labor....
Continuous electronic fetal monitoring was developed to screen for signs of hypoxic-ischemic encephalopathy, cerebral palsy, and impending fetal death during labor. Because these events have a low prevalence, continuous electronic fetal monitoring has a false-positive rate of 99%. The widespread use of continuous electronic fetal monitoring has increased operative and cesarean delivery rates without improved neonatal outcomes, but its use is appropriate in high-risk labor. Structured intermittent auscultation is an underused form of fetal monitoring; when employed during low-risk labor, it can lower rates of operative and cesarean deliveries with neonatal outcomes similar to those of continuous electronic fetal monitoring. However, structured intermittent auscultation remains difficult to implement because of barriers in nurse staffing and physician oversight. The National Institute of Child Health and Human Development terminology is used when reviewing continuous electronic fetal monitoring and delineates fetal risk by three categories. Category I tracings reflect a lack of fetal acidosis and do not require intervention. Category II tracings are indeterminate, are present in the majority of laboring patients, and can encompass monitoring predictive of clinically normal to rapidly developing acidosis. Presence of moderate fetal heart rate variability and accelerations with absence of recurrent pathologic decelerations provides reassurance that acidosis is not present. Category II tracing abnormalities can be addressed by treating reversible causes and providing intrauterine resuscitation, which includes stopping uterine-stimulating agents, fetal scalp stimulation and/or maternal repositioning, intravenous fluids, or oxygen. Recurrent deep variable decelerations can be corrected with amnioinfusion. Category III tracings are highly concerning for fetal acidosis, and delivery should be expedited if immediate interventions do not improve the tracing.
Topics: Adult; Cardiotocography; Curriculum; Education, Medical, Continuing; Female; Fetal Monitoring; Health Personnel; Humans; Male; Middle Aged; Perinatal Care; Practice Guidelines as Topic; Pregnancy; Risk Assessment; United States
PubMed: 32735438
DOI: No ID Found -
Acta Clinica Croatica Jun 2019Regional centro-axial anaesthesia, primarily spinal block, is the preferred method of anaesthesia for elective caesarean section because it entails fewer risks for the...
Regional centro-axial anaesthesia, primarily spinal block, is the preferred method of anaesthesia for elective caesarean section because it entails fewer risks for the mother and the foetus compared to general anaesthesia. The most common side effect associated with spinal block is hypotension due to sympatholysis, occurring in up to 75% of cases. Spinal block-induced sympatholysis leads to vasodilatation and consequently causes maternal hypotension, which may compromise uterine blood flow and foetal circulation, and thus cause foetal hypoxia, bradycardia and acidosis. The selection of the most efficient treatment strategy to achieve haemodynamic stability during spinal anaesthesia for caesarean section continues to be one of the main challenges in obstetric anaesthesiology. A number of measures for the prevention and treatment of spinal block-induced hypotension are used in clinical practice, such as preloading and coloading with crystalloid and/or colloid infusion, wrapping of lower limbs with compression stockings or bandages, administering an optimal dose of local anaesthetic and achieving an optimal spinal block level, left tilt positioning, and administering inotropes and vasopressors. Instead of administering vasopressors after a drop in blood pressure has already occurred, the latest algorithms recommend a prophylactic administration of vasopressor infusion. The preferred vasoconstrictor in this case is phenylephrine, which is associated with a lower incidence of foetal acidosis, and maternal nausea and vomiting compared to other vasoconstrictors.
Topics: Adult; Anesthesia, Obstetrical; Anesthesia, Spinal; Blood Pressure; Cesarean Section; Female; Humans; Hypotension; Pregnancy
PubMed: 31741565
DOI: 10.20471/acc.2019.58.s1.13 -
American Journal of Obstetrics and... May 2023Normal birth is a eustress reaction, a beneficial hedonic stress with extremely high catecholamines that protects us from intrauterine hypoxia and assists in the rapid... (Review)
Review
Normal birth is a eustress reaction, a beneficial hedonic stress with extremely high catecholamines that protects us from intrauterine hypoxia and assists in the rapid shift to extrauterine life. Occasionally the cellular O requirement becomes critical and an O deficit in blood (hypoxemia) may evolve to a tissue deficit (hypoxia) and finally a risk of organ damage (asphyxia). An increase in H concentration is reflected in a decrease in pH, which together with increased base deficit is a proxy for the level of fetal O deficit. Base deficit (or its negative value, base excess) was introduced to reflect the metabolic component of a low pH and to distinguish from the respiratory cause of a low pH, which is a high CO concentration. Base deficit is a theoretical estimate and not a measured parameter, calculated by the blood gas analyzer from values of pH, the partial pressure of CO, and hemoglobin. Different brands of analyzers use different calculation equations, and base deficit values can thus differ by multiples. This could influence the diagnosis of metabolic acidosis, which is commonly defined as a pH <7.00 combined with a base deficit ≥12.0 mmol/L in umbilical cord arterial blood. Base deficit can be calculated as base deficit in blood (or actual base deficit) or base deficit in extracellular fluid (or standard base deficit). The extracellular fluid compartment represents the blood volume diluted with the interstitial fluid. Base deficit in extracellular fluid is advocated for fetal blood because a high partial pressure of CO (hypercapnia) is common in newborns without concomitant hypoxia, and hypercapnia has a strong influence on the pH value, then termed respiratory acidosis. An increase in partial pressure of CO causes less increase in base deficit in extracellular fluid than in base deficit in blood, thus base deficit in extracellular fluid better represents the metabolic component of acidosis. The different types of base deficit for defining metabolic acidosis in cord blood have unfortunately not been noticed by many obstetrical experts and organizations. In addition to an increase in H concentration, the lactate production is accelerated during hypoxia and anaerobic metabolism. There is no global consensus on definitions of normal cord blood gases and lactate, and different cutoff values for abnormality are used. At a pH <7.20, 7% to 9% of newborns are deemed academic; at <7.10, 1% to 3%; and at <7.00, 0.26% to 1.3%. From numerous studies of different eras and sizes, it can firmly be concluded that in the cord artery, the statistically defined lower pH limit (mean -2 standard deviations) is 7.10. Given that the pH for optimal enzyme activity differs between different cell types and organs, it seems difficult to establish a general biologically critical pH limit. The blood gases and lactate in cord blood change with the progression of pregnancy toward a mixed metabolic and respiratory acidemia because of increased metabolism and CO production in the growing fetus. Gestational age-adjusted normal reference values have accordingly been published for pH and lactate, and they associate with Apgar score slightly better than stationary cutoffs, but they are not widely used in clinical practice. On the basis of good-quality data, it is reasonable to set a cord artery lactate cutoff (mean +2 standard deviations) at 10 mmol/L at 39 to 40 weeks' gestation. For base deficit, it is not possible to establish statistically defined reference values because base deficit is calculated with different equations, and there is no consensus on which to use. Arterial cord blood represents the fetus better than venous blood, and samples from both vessels are needed to validate the arterial origin. A venoarterial pH gradient of <0.02 is commonly used to differentiate arterial from venous samples. Reference values for pH in cord venous blood have been determined, but venous blood comes from the placenta after clearance of a surplus of arterial CO, and base deficit in venous blood then overestimates the metabolic component of fetal acidosis. The ambition to increase neonatal hemoglobin and iron depots by delaying cord clamping after birth results in falsely acidic blood gas and lactate values if the blood sampling is also delayed. Within seconds after birth, sour metabolites accumulated in peripheral tissues and organs will flood into the central circulation and further to the cord arteries when the newborn starts to breathe, move, and cry. This influence of "hidden acidosis" can be avoided by needle puncture of unclamped cord vessels and blood collection immediately after birth. Because of a continuing anaerobic glycolysis in the collected blood, it should be analyzed within 5 minutes to not result in a falsely high lactate value. If the syringe is placed in ice slurry, the time limit is 20 minutes. For pH, it is reasonable to wait no longer than 15 minutes if not in ice. Routine analyses of cord blood gases enable perinatal audits to gain the wisdom of hindsight, to maintain quality assurance at a maternity unit over years by following the rate of neonatal acidosis, to compare results between hospitals on regional or national bases, and to obtain an objective outcome measure in clinical research. Given that the intrapartum cardiotocogram is an uncertain proxy for fetal hypoxia, and there is no strong correlation between pathologic cardiotocograms and fetal acidosis, a cord artery pH may help rather than hurt a staff person subjected to a malpractice suit based on undesirable cardiotocogram patterns. Contrary to common beliefs and assumptions, up to 90% of cases of cerebral palsy do not originate from intrapartum events. Future research will elucidate whether cell injury markers with point-of-care analysis will become valuable in improving the dating of perinatal injuries and differentiating hypoxic from nonhypoxic injuries.
Topics: Infant, Newborn; Pregnancy; Female; Humans; Lactic Acid; Reference Values; Hypercapnia; Carbon Dioxide; Ice; Acidosis; Fetal Blood; Infant, Newborn, Diseases; Fetal Diseases; Umbilical Cord; Hypoxia; Hydrogen-Ion Concentration
PubMed: 37164495
DOI: 10.1016/j.ajog.2022.07.001 -
The Journal of Clinical Endocrinology... Nov 2022Diabetic ketoacidosis (DKA) in pregnancy is an obstetric emergency with risk of maternofetal death.
CONTEXT
Diabetic ketoacidosis (DKA) in pregnancy is an obstetric emergency with risk of maternofetal death.
OBJECTIVE
This work aimed to evaluate DKA events in pregnant women admitted to our inpatient obstetric service, and to examine associated clinical risk factors, presentation, and pregnancy outcomes.
METHODS
A retrospective cohort study was conducted at the Mayo Clinic, Rochester, Minnesota, USA, and included women aged 17 to 45 years who were treated for DKA during pregnancy between January 1, 2004 and December 31, 2021. Main outcome measures included maternal and fetal death along with a broad spectrum of maternal and fetal pregnancy outcomes.
RESULTS
A total of 71 DKA events were identified in 58 pregnancies among 51 women, 48 (82.8%) of whom had type 1 diabetes. There were no maternal deaths, but fetal demise occurred in 10 (17.2%) pregnancies (6 miscarriages and 4 stillbirths). Maternal social stressors were frequently present (n = 30, 51.0%), and glycemic control was suboptimal (median first trimester glycated hemoglobin A1c = 9.0%). Preeclampsia was diagnosed in 17 (29.3%) pregnancies. Infants born to women with DKA were large for gestational age (n = 16, 33.3%), suffered from neonatal hypoglycemia (n = 29, 60.4%) and required intensive care unit admission (n = 25, 52.1%).
CONCLUSION
DKA is associated with a high rate of maternofetal morbidity and fetal loss. Prenatal education strategies for women with diabetes mellitus should include a strong focus on DKA prevention, and clinicians and patients should have a high index of suspicion for DKA in all pregnant women who present with symptoms that could be attributed to this condition.
Topics: Infant, Newborn; Female; Humans; Pregnancy; Diabetic Ketoacidosis; Retrospective Studies; Diabetes Mellitus, Type 1; Pregnancy Outcome; Risk Factors
PubMed: 35917830
DOI: 10.1210/clinem/dgac464 -
Frontiers in Pediatrics 2022Electronic fetal monitoring (EFM) was introduced into obstetric practice in 1970 as a test to identify early deterioration of fetal acid-base balance in the expectation... (Review)
Review
Electronic fetal monitoring (EFM) was introduced into obstetric practice in 1970 as a test to identify early deterioration of fetal acid-base balance in the expectation that prompt intervention ("rescue") would reduce neonatal morbidity and mortality. Clinical trials using a variety of visual or computer-based classifications and algorithms for intervention have failed repeatedly to demonstrate improved immediate or long-term outcomes with this technique, which has, however, contributed to an increased rate of operative deliveries (deemed "unnecessary"). In this review, we discuss the limitations of current classifications of FHR patterns and management guidelines based on them. We argue that these clinical and computer-based formulations pay too much attention to the detection of systemic fetal acidosis/hypoxia and too little attention not only to the pathophysiology of FHR patterns but to the provenance of fetal neurological injury and to the relationship of intrapartum injury to the condition of the newborn. Although they do not reliably predict fetal acidosis, FHR patterns, properly interpreted in the context of the clinical circumstances, do reliably identify fetal neurological integrity (behavior) and are a biomarker of fetal neurological injury (separate from asphyxia). They provide insight into the mechanisms and trajectory (evolution) of any hypoxic or ischemic threat to the fetus and have particular promise in signaling preventive measures (1) to enhance the outcome, (2) to reduce the frequency of "abnormal" FHR patterns that require urgent intervention, and (3) to inform the decision to provide neuroprotection to the newborn.
PubMed: 36210941
DOI: 10.3389/fped.2022.915344 -
Scientific Reports Nov 2020Inappropriate gestational weight gain (GWG), either above or below the recommended values, has been associated with an increased risk of adverse obstetric outcomes. To...
Inappropriate gestational weight gain (GWG), either above or below the recommended values, has been associated with an increased risk of adverse obstetric outcomes. To evaluate the risks of GWG for foetal acidosis according to pre-pregnancy body mass index (BMI) and mode of delivery, we analysed women with singleton pregnancies between 2011 and 2014 in the Japan Environment and Children's Study. Participants (n = 71,799) were categorised according to pre-pregnancy BMI. GWG was categorised into insufficient, appropriate, or excessive. Foetal acidosis was defined as umbilical artery pH (UmA-pH) < 7.20 or < 7.10. Multiple logistic regressions were performed for each BMI category to identify the risks of GWG for foetal acidosis, accounting for the mode of delivery. Excessive GWG was significantly associated with increased foetal acidosis in overweight women and in women whose pre-pregnancy BMI was 23.0-25.0 kg/m especially in those with vaginal deliveries. Conversely, excessive GWG was not significantly associated with increased foetal acidosis in obese women and in women whose pre-pregnancy BMI was ≥ 25.0 kg/m.
Topics: Acidosis; Adult; Body Mass Index; Cesarean Section; Child; Economic Status; Educational Status; Female; Fetal Diseases; Fetus; Gestational Weight Gain; Humans; Hydrogen-Ion Concentration; Japan; Logistic Models; Obesity; Parturition; Pregnancy; Prospective Studies
PubMed: 33230184
DOI: 10.1038/s41598-020-77429-9 -
Maedica Dec 2023ST waveform analysis (STAN) was introduced to improve the interpretation of cardiotocography (CTG) resulting in reduction of unnecessary interventions and metabolic...
ST waveform analysis (STAN) was introduced to improve the interpretation of cardiotocography (CTG) resulting in reduction of unnecessary interventions and metabolic acidosis. A systematic review was conducted with the aim to evaluate the effect of STAN method compared with isolated CTG on perinatal and neonatal outcomes. A search of electronic databases (PubMed, Cochrane, Scopus) was conducted to identify randomized controlled trials (RCTs) in English language. Outcomes considered operative deliveries, fetal blood sampling (FBS), metabolic acidosis, perinatal and neonatal death, neonatal seizures, neonatal encephalopathy, transfer to the neonatal intensive care unit (NICU) and Apgar score. Seven RCTs were included in the present review. The first two RCTs showed that the combination of STAN and CTG was a better option than using CTG alone, because there was a documented reduction in the rate of operative deliveries due to fetal distress and metabolic acidosis. The following studies showed no statistically significant changes with the combination of methods, except from a reduction in FBS. The findings from the RCTs were inconclusive. Most studies did not demonstrate a superiority of the combination regarding operative deliveries and neonatal outcomes but there were many methodological differences between the trials.
PubMed: 38348066
DOI: 10.26574/maedica.2023.18.4.684 -
Sensors (Basel, Switzerland) Aug 2018This article reviews existing clinical practices and sensor research undertaken to monitor fetal well-being during labour. Current clinical practices that include fetal... (Review)
Review
This article reviews existing clinical practices and sensor research undertaken to monitor fetal well-being during labour. Current clinical practices that include fetal heart rate monitoring and fetal scalp blood sampling are shown to be either inadequate or time-consuming. Monitoring of lactate in blood is identified as a potential alternative for intrapartum fetal monitoring due to its ability to distinguish between different types of acidosis. A literature review from a medical and technical perspective is presented to identify the current advancements in the field of lactate sensors for this application. It is concluded that a less invasive and a more continuous monitoring device is required to fulfill the clinical needs of intrapartum fetal monitoring. Potential specifications for such a system are also presented in this paper.
Topics: Acidosis; Female; Fetal Hypoxia; Fetal Monitoring; Humans; Labor, Obstetric; Lactic Acid; Pregnancy; Scalp
PubMed: 30104478
DOI: 10.3390/s18082648