Sodium bicarbonate: basically useless therapy

Effect of early clinical management on metabolic acidemia in neonates with hypoxic-ischemic encephalopathy

OBJECTIVE

To determine the safety and effectiveness of sodium bicarbonate administration in the management of metabolic acidemia and short-term outcomes in neonates with hypoxic-ischemic encephalopathy (HIE).

STUDY DESIGN

Retrospective cohort study of neonates born at ≥35 weeks of gestation and receiving therapeutic hypothermia. Demographics, pH, lactate, base deficit, treatment, MRI findings, seizure incidence, death prior to discharge were collected.

RESULTS

There was higher mortality (p = 0.010) and injury on MRI (p = 0.008)-primarily deep gray matter (p < 0.001) and cortical injury (p = 0.003)-in the bicarbonate group compared to controls in univariate analysis. The combined outcome of death or abnormal MRI was not significantly associated (OR 1.97, 95% CI 0.80-4.87, p = 0.141) with bicarbonate administration when adjusting for sex, 5-minute Apgar, and initial base deficit.

CONCLUSION

This study demonstrated association between bicarbonate use after HIE and negative short-term outcomes. Future prospective trials could overcome the treatment bias limitation demonstrated in this retrospective study.

Chloride Reduction Therapy with Furosemide: Short-Term Effects in Children with Acute Respiratory Failure

From the perspective of the Stewart approach, it is known that expansion of the sodium chloride ion difference (SCD) induces alkalosis. We investigated the role of SCD expansion by furosemide-induced chloride reduction in pediatric patients with acute respiratory failure. We included patients admitted to our pediatric intensive care unit intubated for acute respiratory failure without underlying diseases, and excluded patients receiving extracorporeal circulation therapy (extracorporeal membrane oxygenation and/or renal replacement therapy). We classified eligible patients into the following two groups: case-those intubated who received furosemide within 24 hours, and control-those intubated who did not receive furosemide within 48 hours. Primary outcomes included SCD, partial pressure of carbon dioxide (PaCO 2 ), and pH results from arterial blood gas samples obtained over 48 hours following intubation. Multiple regression analysis was also performed to evaluate the effects of SCD and PaCO 2 changes on pH. Twenty-six patients were included of which 13 patients were assigned to each of the two groups. A total of 215 gas samples were analyzed. SCD (median [mEq/L] [interquartile range]) 48 hours after intubation significantly increased in the case group compared with the control group (37 [33-38] vs. 31 [30-34]; p  = 0.005). Although hypercapnia persisted in the case group, the pH (median [interquartile range]) remained unchanged in both groups (7.454 [7.420-7.467] vs. 7.425 [7.421-7.436]; p  = 0.089). SCD and PaCO 2 were independently associated with pH ( p  < 0.001 for each regression coefficient). As a result, we provide evidence that SCD expansion with furosemide may be useful in maintaining pH within the normal range in pediatric patients with acute respiratory failure complicated by concurrent metabolic acidosis.

Incidence of Intracranial Hemorrhage in Patients Younger Than 2 Months Receiving Sodium Bicarbonate 4.2% vs 8.4

OBJECTIVE

To assess the incidence of intracranial hemorrhage (ICH), including intraventricular hemorrhage, in infants receiving 4.2% or 8.4% sodium bicarbonate.

METHODS

This is a single-center retrospective chart review of neonates and infants with a gestational age (GA) >32 weeks and a postnatal age <2 months who received sodium bicarbonate in an intensive care unit at an academic tertiary children's hospital. The primary outcome was the incidence of ICH in patients with baseline and follow-up head imaging. The secondary outcome was the incidence of ICH on follow-up head imaging, with or without baseline head imaging.

RESULTS

There were 351 patients screened, with 135 meeting inclusion criteria. Of these, 84% were born ≥37 weeks GA. Forty-two met the criteria for the primary outcome. Study participants were further subdivided into 3 groups based on the concentration of sodium bicarbonate received: only 4.2%, only 8.4%, or a mixed group that received at least 1 dose each of 4.2% and 8.4%. Intracranial hemorrhage was noted in 1 patient in each group: 8.3%, 5.6%, and 8.3%, respectively (p = 1.00). For the secondary outcome, 11 ICHs were seen on head imaging: 11.3%, 3.8%, and 10%, respectively. There was no statistically significant difference in the incidence of ICH (p = 0.325).

CONCLUSIONS

The incidence of ICH in term neonates and infants was not significantly different in those receiving 4.2% vs 8.4% sodium bicarbonate. Although additional studies are needed, this study suggests it may be possible to safely expand the use of 8.4% in neonates/infants ≥37 weeks GA. These results should not be applied to preterm neonates (<37 weeks GA and/or <1500 g) or neonates with additional ICH risk factors.

The practices of intravenous sodium bicarbonate therapy in neonatal intensive care units: A multi-country survey

A common occurrence in the neonatal intensive care unit (NICU) is metabolic acidosis. Sodium bicarbonate (SB) has been widely used, but there is insufficient evidence on how SB affects neonates in NICUs with metabolic acidosis. The worsening of intracellular acidosis, the impairment of myocardial function, fluctuations in cerebral blood flow, and intracranial hemorrhage are some of the unfavorable effects of SB treatment in neonates that have been documented in the literature. This study aimed to explore neonatologists' practices for using intravenous SB (ISB) in NICUs. A multi-country survey was carried out in 2022 using an online questionnaire sent to neonatologists in various countries in order to gather information about the use of ISB in NICUs. A previously validated questionnaire was adapted and used in this study. The response rate was 67%. The findings show that 91.2% of neonatologists were using SB to correct metabolic acidosis in the NICU; 71.4% did not have written guidelines for using sodium bicarbonate. The majority of them (78.9%) reported that dosage is included in their guidelines for the use of ISB. The findings of this study emphasize the critical importance of providing guidelines in using ISB for managing metabolic acidosis in NICU to standardize procedures and reduce the use of potentially unsuitable and unsafe treatments, as it has been shown that 71.4% of neonatologists worldwide use sodium bicarbonate without guidelines.

Acute Effects of Sodium Bicarbonate in Children with Congenital Heart Disease with Biventricular Circulation in Non-cardiac Arrest Situations

Despite the controversy, sodium bicarbonate is a commonly used medication in critically ill patients of all ages. There is a lack of data on the acute impact on hemodynamic parameters, biomarker indicators of cardiac output, and changes in vasoinotropic support after sodium bicarbonate therapy. In our retrospective study on children with biventricular circulation in pediatric cardiac intensive care unit receiving bicarbonate therapy: we analyzed its effects on arterial blood gases, heart rate, blood pressure (BP), central venous pressures (CVP), cerebral and renal near-infrared spectroscopy (NIRS), changes in vasoinotropic and ventilator changes before and after sodium bicarbonate administration. Thirty-one administrations of sodium bicarbonate in 23 patients with congenital heart disease without residual shunts were analyzed. The average age was 15.4 months, weight 7.7 kg, and the average bicarbonate dose was 1 meq/kg. There was an increase in arterial pH from 7.24 to 7.30 (p = 0.14) and bicarbonate changed from 18 to 20 mEq/L (p = 0.23). No clinically significant changes were found in the following parameters: heart rate (141 ± 20.1 to 136 ± 19), systolic BP (84 ± 17 to 86 ± 14 mmHg), diastolic BP (48 ± 12 to 49 ± 12 mmHg), cerebral NIRS (64 ± 12 to 65 ± 12), renal NIRS (80 ± 10 to 81 ± 7), CVP (9 ± 3 to 10 ± 4 mmHg), paCO₂ (45 ± 26 to 42 ± 7 mmHg), paO₂ (143 ± 78 to 127 ± 59 mmHg), serum lactate (2.2 ± 2.7 to 3.6 ± 3.8 mmol/L), and vasoinotropic score (7.5 ± 5.0 to 7.7 ± 4.7). Outside of a change in serum pH and bicarbonate levels no other significant changes were noted after sodium bicarbonate administration in children with congenital heart disease with fully septated, biventricular circulation. There was no improvement in systemic oxygen delivery.

Sodium Bicarbonate Use During Pediatric Cardiopulmonary Resuscitation: A Secondary Analysis of the ICU-RESUScitation Project Trial

OBJECTIVES

To evaluate associations between sodium bicarbonate use and outcomes during pediatric in-hospital cardiac arrest (p-IHCA).

DESIGN

Prespecified secondary analysis of a prospective, multicenter cluster randomized interventional trial.

SETTING

Eighteen participating ICUs of the ICU-RESUScitation Project (NCT02837497).

PATIENTS

Children less than or equal to 18 years old and greater than or equal to 37 weeks post conceptual age who received chest compressions of any duration from October 2016 to March 2021.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Child and event characteristics, prearrest laboratory values (2-6 hr prior to p-IHCA), pre- and intraarrest hemodynamics, and outcomes were collected. In a propensity score weighted cohort, the relationships between sodium bicarbonate use and outcomes were assessed. The primary outcome was survival to hospital discharge. Secondary outcomes included return of spontaneous circulation (ROSC) and survival to hospital discharge with favorable neurologic outcome. Of 1,100 index cardiopulmonary resuscitation events, median age was 0.63 years (interquartile range, 0.19-3.81 yr); 528 (48.0%) received sodium bicarbonate; 773 (70.3%) achieved ROSC; 642 (58.4%) survived to hospital discharge; and 596 (54.2%) survived to hospital discharge with favorable neurologic outcome. Among the weighted cohort, sodium bicarbonate use was associated with lower survival to hospital discharge rate (adjusted odds ratio [aOR], 0.7; 95% CI, 0.54-0.92; p = 0.01) and lower survival to hospital discharge with favorable neurologic outcome rate (aOR, 0.69; 95% CI, 0.53-0.91; p = 0.007). Sodium bicarbonate use was not associated with ROSC (aOR, 0.91; 95% CI, 0.62-1.34; p = 0.621).

CONCLUSIONS

In this propensity weighted multicenter cohort study of p-IHCA, sodium bicarbonate use was common and associated with lower rates of survival to hospital discharge.

The effects of sodium bicarbonate infusion on cerebrovascular function in newborn pigs

BACKGROUND

Sodium bicarbonate (NaHCO₃) is no longer recommended by the Neonatal Resuscitation Program (NRP), but is still being used by some neonatologists. The effects of NaHCO₃ on cerebral hemodynamics are unclear. Therefore, we investigated the effects of NaHCO₃ on cerebral blood flow (CBF) and cerebrovascular function using a newborn piglet model.

METHODS

Newborn pigs were anesthetized, intubated, and ventilated. Cranial windows were implanted to evaluate changes in pial arteriolar diameters (PADs) as a surrogate for CBF during a 4-h intravenous infusion of 3% NaHCO₃. Cerebrovascular reactivity to vasodilators and vasoconstrictors was investigated during vehicle control and during NaHCO₃ infusion.

RESULTS

NaHCO₃ infusion caused significant and progressive pial arteriolar vasoconstrictions. During NaHCO₃ infusion, cerebrovascular reactivity was preserved. Adding vasodilators decreased cerebral vasoconstriction, while adding vasoconstrictors exaggerated cerebral vasoconstriction.

CONCLUSIONS

Intravenous infusion of NaHCO₃ over 4 h caused progressive vasoconstriction of pial arterioles. Cerebrovascular function evaluated by the responses of pial arterioles to physiologically relevant vasoconstrictors and vasodilators was preserved during NaHCO₃ infusion. A notable additional reduction of PADs was observed during NaHCO₃ infusion in the presence of vasoconstrictors. Extrapolating our findings to human neonates should alarm the clinicians that using NaHCO₃ in neonates may cause cerebral hypoperfusion.

IMPACT

Cerebral vasoconstriction occurs during slow infusion of 3% diluted NaHCO₃. Cerebral vasoconstriction is exaggerated when another vasoconstrictor is added during NaHCO₃ infusion. Cerebrovascular function is preserved during NaHCO₃ infusion. Clinicians should be aware of the risk of cerebral hypoperfusion with NaHCO₃ infusion in vulnerable neonates.

Pediatric Cardiac Arrest Outcomes in the United States: A Nationwide Database Cohort Study

Background

Knowledge about the causes and outcomes of pediatric cardiac arrest in the emergency department is limited. The aim of our study was to evaluate the characteristics and outcomes of pediatric cardiac arrest in the emergency department (EDCA) and inpatient (IPCA) settings in the United States using a large database designed to provide nationwide estimates.

Methods

We performed a retrospective cohort study using the Nationwide Emergency Department Sample (NEDS), a database that includes both ED and inpatient encounters. The NEDS was analyzed for episodes of cardiac arrest between 2016-2018 in patients aged ≤18 years. Patients with cardiac arrest were identified using the International Classification of Diseases, 10th revision codes.

Results

A total of 15,348 pediatric cardiac arrest events with cardiopulmonary resuscitation were recorded, of which 13,239 had EDCA and 2,109 had IPCA. A lower survival rate of 19% was observed for EDCA compared to 40.4% for IPCA. While more than half of the EDCA events had no associated diagnoses, trauma (15.6%), respiratory failure (5%), asphyxiation (2.7%), acidosis (2.4%), and ventricular arrhythmia (1.4%) were associated with the remaining events. In comparison, the most frequently associated diagnoses for IPCA were respiratory failure (75.8%), acidosis (43.9%), acute kidney injury (27.2%), trauma (27.1%), and sepsis (22.5%). 

Conclusions

Survival rates for EDCA were less than half of that for IPCA. The low survival rates along with the distinctive characteristics of EDCA events suggest the need for further research in this area to identify remediable factors and improve survival.

Acidified Feedings in Preterm Infants: A Historical and Physiological Perspective

The use of acidified milk for feeding infants has a long, interesting history that appears to have developed from the use of buttermilk in Holland as early as the late 19th century for feeding infants with diarrhea. Physicians in the early 20th century assumed that the observed benefits were from buttermilk's acidity leading to the practice of acidifying infant formula. The historical and physiological perspective on the use of acidified infant formula is now especially relevant with the emergence of an acidified liquid human milk fortifier for preterm infants. Here, we review that history, with a deeper dive into the contemporary research on the use of acidified human milk fortifiers, the consequences for preterm infants, and the underlying physiological mechanisms. KEY POINTS: · In the late 19th and early 20th century acidified feedings were in common use for sick infants.. · By the mid-20th century, acidified feedings tested in preterm infants resulted in acidic physiology and poor growth.. · The current practice of acidifying feedings in preterm infants has been associated with metabolic acidosis, poor tolerance, and delayed growth..

Effectiveness of Sodium Bicarbonate Infusion on Mortality in Critically Ill Children With Metabolic Acidosis

Objective: Metabolic acidosis often occurs in the paediatric intensive care unit (PICU). Although sodium bicarbonate (SB) has been widely used in paediatrics, data on the effect of SB on children with metabolic acidosis in the PICU are scarce.

Methods: Patients with metabolic acidosis who were treated with SB within 48 h of PICU admission were screened. Multivariate logistic regression, subgroup analysis, and propensity score matching (PSM) were used to investigate the relationships between SB infusion and clinical outcomes.

Results: A total of 1,595 patients with metabolic acidosis were enrolled in this study. In the multivariate logistic regression model, SB infusion was not correlated with in-hospital mortality (odds ratio (OR) 0.87, 95% confidence interval (CI) 0.47–1.63, p = 0.668), but was significantly correlated with hypernatraemia (OR 1.98, 95% CI 1.14–3.46, p = 0.016), hypokalaemia (OR 2.01, 95% CI 1.36–2.96, p < 0.001), and hypocalcaemia (OR 4.29, 95% CI 2.92–6.31, p < 0.001). In the pH value, lactate level, acute kidney injury level, age grouping, and anion gap level subgroups, the ORs for SB and in-hospital mortality were not statistically significant. After PSM, the results remained unchanged.

Conclusion: SB infusion does not reduce the in-hospital mortality of severely ill children with metabolic acidosis and increases the risk of hypernatraemia, hypokalaemia, and hypocalcaemia. More effort should be focused on eliminating the causes of metabolic acidosis rather than SB infusion.

Ibuprofen-Associated Hypokalemia and Metabolic Acidosis: Systematic Literature Review

OBJECTIVE

Ibuprofen is a widely used nonsteroidal anti-inflammatory drug, which has been occasionally associated with hypokalemia and metabolic acidosis. The objective of this report is to analyze the literature on this issue and to address the underlying pathophysiology.

DATA SOURCES

Excerpta Medica, the National Library of Medicine, and Web of Science were searched from inception to July 16, 2021.

STUDY SELECTION AND DATA EXTRACTION

Papers reporting individually documented humans on ibuprofen with hypokalemia, acidosis, or both were retained. Data were extracted using a checklist.

DATA SYNTHESIS

For the final analysis, we evaluated 41 reports describing 50 cases (26 males and 24 females; 36 adults and 14 children) with often profound hypokalemia, acidosis, or both after ingestion of ibuprofen. Twenty-six cases were acute and 24 long term. Hypokalemia and acidosis occurred not only after ingestion of very high doses but also after ingestion of moderately high or even normal doses of ibuprofen. Laboratory values consistent with an excessive urinary potassium excretion or an altered urinary acidification were often disclosed in most cases. Discontinuation of ibuprofen resulted in a resolution of hypokalemia and acidosis within days in 47 cases. The course was lethal in 3 cases.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This review highlights potentially fatal side effects of ibuprofen and can help doctors who are confronted with such a situation.

CONCLUSIONS

These data highlight the potential of ibuprofen to occasionally induce hypokalemia and acidosis of renal origin. Discontinuation of ibuprofen results in a resolution within days.

Resuscitation 2020: Proceedings From the NeoHeart 2020 International Conference

Resuscitation guidelines are developed and revised by medical societies throughout the world. These guidelines are increasingly based on evidence from preclinical and clinical research. The International Liaison Committee on Resuscitation reviews evidence for each resuscitation practice and provides summary consensus statements that inform resuscitation guideline committees. A similar process is used for different populations including neonatal, pediatric, and adult resuscitation. The NeoHeart 2020 Conference brought together experts in resuscitation to discuss recent evidence and guidelines for resuscitation practices. This review summarizes the main focus of discussion from this symposium.

Challenges in respiratory management during therapeutic hypothermia for neonatal encephalopathy

Neonatal encephalopathy (NE) is a serious condition with devastating neurological outcomes that can impact oxygenation and ventilation. The currently recommended therapeutic hypothermia (TH) for these infants may also has several respiratory implications. It decreases metabolic rate and oxygen demands; however, it increases oxygen solubility in the blood and impacts its release to peripheral tissue including the brain. Respiratory management of infants treated with TH should aim for minimizing exposure to hypocapnia or hyperoxia. Inspiratory gas should be heated to 37 °C and humidified to prevent airway and alveolar injury. Blood gas values should be corrected to the core temperature during TH and the use of alkaline buffers is discouraged. While mild sedation/analgesia may ameliorate the discomfort related to cooling, paralytic agents/heavy sedation should be used with caution considering their side effects. Finally, the use of caffeine still needs careful investigation in this population.

Hemodynamic optimization for neonates with neonatal encephalopathy caused by a hypoxic ischemic event: Physiological and therapeutic considerations

Neonatal encephalopathy due to a hypoxic-ischemic event is commonly associated with cardiac dysfunction and acute pulmonary hypertension; both therapeutic hypothermia and rewarming modify loading conditions and blood flow. The pathophysiological contributors to disease are complex with a high degree of clinical overlap and traditional bedside measures used to assess circulatory adequacy have multiple confounders. Comprehensive, quantitative echocardiography may be used to delineate the relative contribution of lung parenchymal, pulmonary vascular, and cardiac disease to hypotension and/or hypoxemic respiratory failure. In this review, we provide a detailed overview of the contributors to hemodynamic instability following perinatal hypoxic-ischemic injury. Our proposed approach to therapy focuses on physiopathological considerations with interventions individualized to this potentially complex condition and considers the pharmacological idiosyncrasies, which may occur among neonates with NE presenting with multiorgan dysfunction while undergoing therapeutic hypothermia.

Use of intravenous sodium bicarbonate in neonatal intensive care units in Italy: a nationwide survey

Background

Metabolic Acidosis (MA) is a disturbance of the acid-base balance that can occur in preterm and critically ill term neonates due to different etiologies. Intravenous sodium bicarbonate (SB) has been traditionally used to correct such unbalance, despite the lack of evidence about its safety and efficacy. In literature, reported undesirable effects of treatment with SB in neonates include worsening of intracellular acidosis, impairment of myocardial function, cerebral blood flow fluctuations and intracranial hemorrhage. A national survey was conducted by the Neonatal Pharmacotherapy Study Group of the Italian Society of Neonatology with the aim to assess and describe attitudes and practices concerning the use of SB, particularly for the treatment of MA in Italian NICUs.

Methods

A questionnaire regarding treatment of MA and SB prescription habits was sent to the directors of 120 Italian NICUs from June 2017 to March 2018.

Results

The survey response rate was 97.5% (117/120 centers). Findings showed that in 55% of the surveyed NICUs (64/117 units) it is common practice to correct MA with intravenous SB. On the other hand, the remaining 45% of the units try to solve the metabolic disturbances adopting different approaches (improving perfusion, adjusting ventilation parameters or increasing blood volume). Moreover, to prevent the occurrence of MA, 37.6% of the NICUs (44/117) include buffer salts (lactate, acetate or both) in parenteral nutrition prescriptions. SB is also used as a treatment for other conditions, mainly pathologies with bicarbonate loss and tubular acidosis (respectively in 53.8 and 32.5% of the NICUs).

Conclusion

This survey showed how SB is a commonly used treatment for MA in more than half of Italian NICUs, with indications and prescription criteria that significantly vary across centers. Based on current knowledge, it is reasonable to suggest that the management of neonatal MA should be firstly directed to identify the underlying disorders. Thus, the use of SB should be reserved only for selected cases, also considering the severity of SB adverse effects and the lack of evidence about its efficacy. Guidance for the management of MA is required to harmonize practices and reduce the use of potentially inappropriate and unsafe treatments.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13052-021-00955-3.

Sodium bicarbonate administration during in-hospital pediatric cardiac arrest: A systematic review and meta-analysis

BACKGROUND

Current American Heart Association Pediatric Life Support (PLS) guidelines do not recommend the routine use of sodium bicarbonate (SB) during cardiac arrest in pediatric patients. However, SB administration during pediatric resuscitation is still common in clinical practice. The objective of this study was to assess the impact of SB on mortality and neurological outcomes in pediatric patients with in-hospital cardiac arrest.

METHODS

We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials from inception to January 2021. We included studies of pediatric patients that had two treatment arms (treated with SB or not treated with SB) during in-hospital cardiac arrest (IHCA). Risk of bias was assessed using the Newcastle-Ottawa Scale and the certainty of evidence was assessed using GRADE system.

RESULTS

We included 7 observational studies with a total of 4877 pediatric in-hospital cardiac arrest patients. Meta-analysis showed that SB administration during pediatric cardiac resuscitation was associated with a significantly decreased rate of survival to hospital discharge (odds ratio [OR], 0.40; 95% confidence interval [CI], 0.25-0.63, p value = 0.0003). There were insufficient studies for 24-h survival and neurologic outcomes analysis. The subgroup analysis showed a significantly decreased rate of survival to hospital discharge in both the "before 2010" subgroup (OR 0.47; 95% CI 0.30-0.73; p value = 0.006) and the "after 2010" subgroup (OR 0.46; 95% CI 0.25-0.87; p value = 0.02). The certainty of evidence ranged from very low to low.

CONCLUSIONS

This meta-analysis of non-randomized studies supported current PLS guideline that routine administration of SB is not recommended in pediatric cardiac arrest except in special resuscitation situations.

TRIAL REGISTRATION

The protocol was registered with PROSPERO on 8 August 2020 (registration number: CRD42020197837).

Neonatal Metabolic Acidosis in the Neonatal Intensive Care Unit: What Are the Genetic Causes?

Neonatal metabolic acidosis (NMA) is a common problem, particularly in critically ill patients in neonatal intensive care units (NICUs). Complex etiologies and atypical clinical signs make diagnosis difficult; thus, it is crucial to investigate the underlying causes of NMA rapidly and provide disorder-specific therapies. Our study aims to provide an overview of the genetic causes of NMA in patients from NICUs. We performed next-generation sequencing (NGS) on neonates with NMA from January 2016 to December 2019. Clinical features, genetic diagnoses, and their effects on clinical interventions were collected for analysis. In the 354 enrolled patients, 131 (37%) received genetic diagnoses; 95 (72.5%) of them were autosomal recessively inherited diseases. Two hundred and fifteen variants spanning 57 genes were classified as pathogenic (P) or likely pathogenic (LP) in 131 patients. The leading cause was metabolic disorders due to 35 genes found in 89 patients (68%). The other 42 NMA patients (32%) with 22 genes had malformations and renal, neuromuscular, and immune-hematological disorders. Seven genes (MMUT, MMACHC, CHD7, NPHS1, OTC, IVD, and PHOX2B) were noted in more than four patients, accounting for 48.9% (64/131) of the identified P/LP variants. Forty-six diagnosed patients with uncorrected NMA died or gave up. In conclusion, 37% of neonates with metabolic acidosis had genetic disorders. Next-generation sequencing should be considered when investigating the etiology of NMA in NICUs. Based on early molecular diagnoses, valuable treatment options can be provided for some genetic diseases to achieve better outcomes.

The therapeutic importance of acid-base balance

Baking soda and vinegar have been used as home remedies for generations and today we are only a mouse-click away from claims that baking soda, lemon juice, and apple cider vinegar are miracles cures for everything from cancer to COVID-19. Despite these specious claims, the therapeutic value of controlling acid-base balance is indisputable and is the basis of Food and Drug Administration-approved treatments for constipation, epilepsy, metabolic acidosis, and peptic ulcers. In this narrative review, we present evidence in support of the current and potential therapeutic value of countering local and systemic acid-base imbalances, several of which do in fact involve the administration of baking soda (sodium bicarbonate). Furthermore, we discuss the side effects of pharmaceuticals on acid-base balance as well as the influence of acid-base status on the pharmacokinetic properties of drugs. Our review considers all major organ systems as well as information relevant to several clinical specialties such as anesthesiology, infectious disease, oncology, dentistry, and surgery.

Use of Sodium Bicarbonate During Pediatric Cardiac Admissions with Cardiac Arrest: Who Gets It and What Does It Do?

The objectives of this study were to characterize the use of sodium bicarbonate in pediatric cardiac admissions that experience cardiac arrest, to determine sodium bicarbonate use over the years, and to determine the impact of sodium bicarbonate on length of admissions, billed charges, and inpatient mortality. A cross-sectional study was conducted utilizing the Pediatric Health Information System database. Characteristics of admissions with and without sodium bicarbonate were initially compared by univariate analyses. The frequency by which sodium bicarbonate was used was compared by year. Regression analyses were conducted to determine the impact of sodium bicarbonate on length of stay, billed charges, and inpatient mortality. A total of 3987 (50.3%) of pediatric cardiac intensive care admissions with cardiac arrest utilized sodium bicarbonate; however, frequency changed from 62.1% in 2004 to 43.7% in 2015. Linear regression analysis demonstrated a decrease in length of stay (-27.5 days, p < 0.01) and billed charges (-$470,906, p < 0.01). Logistic regression analysis demonstrated an increase in mortality (odds ratio 1.77, 95% confidence interval 1.56-2.01). In conclusion, sodium bicarbonate is being used with less frequency over the last years in pediatric cardiac admissions with cardiac arrest. After adjustment for cardiac diagnoses, comorbidities, vasoactive medications, and other resuscitation medications, sodium bicarbonate is independently associated with increased mortality.

Drugs in the delivery room

The need for cardiopulmonary resuscitation in newborns is quite rare, as most non-vigorous infants respond well to effective ventilation. For the minority of babies who do not respond to adequate ventilation, chest compressions are necessary using the preferred two thumb technique. Since effective ventilation remains a key component to successful resuscitation, chest compressions are coordinated with ventilations in a 3:1 ratio. If despite adequate ventilation and compressions, the heart rate remains below 60 beats per minute, epinephrine is indicated. The intravenous route is preferred over the endotracheal route and the recommended dose of epinephrine is 0.01-0.03 mg/kg. This can be repeated every 3-5 min until return of spontaneous circulation is achieved. In rare instances, when there is no response to these above measures and in infants who show evidence of significant hypovolemia, volume replacement should be considered.

Evaluating the quality of the processes of care and clinical outcomes of premature newborns admitted to neonatal intensive care units in Mexico

Objectives

To develop quality of care (QoC) indicators, evaluate the quality of the processes of care (QPC) and clinical outcomes, and analyze the association between the QPC and severe clinical outcomes of preterm newborns admitted to neonatal intensive care units (NICUs).

Design

Mixed methods approach: (1) development of QoC indicators via modified RAND/UCLA method; (2) cross-sectional study of QoC evaluation and (3) multiple logistic regression analysis to ascertain the association between the QPC and severe clinical outcomes.

Setting

Two NICUs belonged to the Mexican Institute of Social Security in Mexico City.

Participants

About 489 preterm neonates (<37 weeks of gestation) without severe congenital anomalies.

Main Outcome Measure(s)

The QoC indicators; ≥60% of recommended QPC and severe clinical outcomes.

Results

The QoC included 10 QPC indicators across four domains: respiratory, nutrition and metabolism, infectious diseases, and screening, and five outcome indicators. The lower QPC indicators were for the nutrition and metabolism domain (17.8% started enteral feeding with human milk, and 20.7% received sodium bicarbonate appropriately). The higher QPC indicator was for the screening domain (97.6% of neonates <30 weeks gestation underwent early (≤14 days) transfontanelar ultrasound). The mean recommended QPC that neonates received was 47.5%. Only 26.6% of neonates received ≥60% of recommended QPC. About 60.7% of neonates developed severe clinical outcomes including mortality and healthcare-related major morbidity. Receiving ≥60% of recommended QPC was associated with a decrease of nearly half of odds of severe clinical outcomes.

Conclusion

The evaluation of the QoC in NICUs is essential to address modifiable gaps in quality.

Effect of Intravenously Administered Crystalloid Solutions on Acid-Base Balance in Domestic Animals

Intravenous fluid therapy can alter plasma acid-base balance. The Stewart approach to acid-base balance is uniquely suited to identify and quantify the effects of the cationic and anionic constituents of crystalloid solutions on plasma pH. The plasma strong ion difference (SID) and weak acid concentrations are similar to those of the administered fluid, more so at higher administration rates and with larger volumes. A crystalloid's in vivo effects on plasma pH are described by 3 general rules: SID > [HCO3-] increases plasma pH (alkalosis); SID < [HCO3-] decreases plasma pH (alkalosis); and SID = [HCO3-] yields no change in plasma pH. The in vitro pH of commercially prepared crystalloid solutions has little to no effect on plasma pH because of their low titratable acidity. Appreciation of IV fluid composition and an understanding of basic physicochemical principles provide therapeutically valuable insights about how and why fluid therapy can produce and correct alterations of plasma acid-base equilibrium. The ideal balanced crystalloid should (1) contain species-specific concentrations of key electrolytes (Na+ , Cl- , K+ , Ca++ , Mg++ ), particularly Na+ and Cl- ; (2) maintain or normalize acid-base balance (provide an appropriate SID); and (3) be isosmotic and isotonic (not induce inappropriate fluid shifts) with normal plasma.

Hemodynamic effects of sodium bicarbonate administration

OBJECTIVE

To describe the hemodynamic changes that occur with sodium bicarbonate (NaHCO₃) administration in premature neonates.

STUDY DESIGN

This retrospective study included premature neonates 23 to 31+6 weeks of gestational age who underwent continuous cardiac and cerebral monitoring as participants in prospective trials at our institution, and who received NaHCO₃ infused over 30 min in the first 24 h of life. Blood pressure (BP), heart rate, cardiac output (CO), SpO₂ and cerebral oximetry (StO₂) were captured every 2 s. A baseline was established for all continuous data and averaged over the 10 min before NaHCO₃ administration. Baseline was compared with measurements over 10 min epochs until 80 min after administration. Arterial blood gases before and within 1 h of administration were also compared. Significance was set at P<0.05.

RESULTS

A total of 36 subjects received NaHCO₃ (1.3±0.3 mEq kg^-1) in the first 24 h (14±8.5 h) of life. NaHCO₃ administration increased pH (7.23 vs 7.28, P<0.01) and decreased base deficit (-8.9 vs -6.8, P<0.01) and PaCO₂ (45 vs 43 mm Hg, P<0.05). There was a transient but significant (P<0.05) decrease in systemic BP coinciding with an increase in cerebral oxygenation without an increase in oxygen extraction. CO did not change.

CONCLUSION

Early postnatal NaHCO₃ administration does not acutely improve CO but does cause transient fluctuations in cerebral and cardiovascular hemodynamics in extremely premature infants.

Pharmacological management of acute kidney injury and chronic kidney disease in neonates

Both acute kidney injury (AKI) and chronic kidney disease (CKD) are seen more frequently in the neonatal intensive care unit (NICU) as advances in supportive care improve the survival of critically ill infants as well as those with severe, congenital kidney and urinary tract anomalies. Many aspects of the infant's care, including fluid balance, electrolyte and mineral homeostasis, acid-base balance, and growth and nutrition require close monitoring by and collaboration among neonatologists, nephrologists, dieticians, and pharmacologists. This educational review summarizes the therapies widely used for neonates with AKI and CKD. Use of these therapies is extrapolated from data in older children and adults or based on clinical experience and case series. There is a critical need for more research on the use of therapies in infants with kidney disease as well as for the development of drug delivery systems and preparations scaled more appropriately for these small patients.

Is Bicarbonate Therapy Useful?

Despite concerns about the negative effects of metabolic acidosis, there is minimal evidence that sodium bicarbonate administration is an effective treatment. In addition, sodium bicarbonate therapy is associated with many adverse effects, including paradoxic intracellular acidosis, hypokalemia, hypocalcemia, hypernatremia, and hyperosmolality. Definitive recommendations regarding bicarbonate therapy are challenging as there is little high-quality evidence available. In most clinical scenarios of metabolic acidosis, treatment efforts should focus on resolution of the underlying cause, and sodium bicarbonate therapy should be used with caution, if at all. An exception to this is kidney disease, wherein sodium bicarbonate therapy may have a valuable role.

Review of splanchnic oximetry in clinical medicine

Global tissue perfusion and oxygenation are important indicators of physiologic function in humans. The monitoring of splanchnic oximetry through the use of near-infrared spectroscopy (NIRS) is an emerging method used to assess tissue oxygenation status. Splanchnic tissue oxygenation (SrSO2) is thought to be potentially of high value in critically ill patients because gastrointestinal organs can often be the first to suffer ischemic injury. During conditions of hypovolemia, cardiac dysfunction, or decreased oxygen-carrying capacity, blood flow is diverted toward vital organs, such as the brain and the heart at the expense of the splanchnic circulation. While monitoring SrSO2 has great potential benefit, there are limitations to the technology and techniques. SrSO2 has been found to have a relatively high degree of variability that can potentially make it difficult to interpret. In addition, because splanchnic organs only lie near the skin surface in children and infants, and energy from currently available sensors only penetrates a few centimeters deep, it can be difficult to use clinically in a noninvasive manner in adults. Research thus far is showing that splanchnic oximetry holds great promise in the ability to monitor patient oxygenation status and detect disease states in humans, especially in pediatric populations.

Informed Consent Should Be a Required Element for Newborn Screening, Even for Disorders with High Benefit-Risk Ratios

Over-enthusiastic newborn screening has often caused substantial harm and has been imposed on the public without adequate information on benefits and risks and without parental consent. This problem will become worse when genomic screening is implemented. For the past 40 years, there has been broad agreement about the criteria for ethically responsible screening, but the criteria have been systematically ignored by policy makers and practitioners. Claims of high benefit and low risk are common, but they require precise definition and documentation, which has often not occurred, undermining claims that involuntary testing is justified. Even when the benefits and risks are well established, it does not automatically follow that involuntary testing is justified, a position supported by the widespread tolerance for parental refusal of immunizations and newborn screening.

Management of the Preterm Infant with Congenital Heart Disease

The premature neonate with congenital heart disease (CHD) represents a challenging population for clinicians and researchers. The interaction between prematurity and CHD is poorly understood; epidemiologic study suggests that premature newborns are more likely to have CHD and that fetuses with CHD are more likely to be born premature. Understanding the key physiologic features of this special patient population is paramount. Clinicians have debated optimal timing for referral for cardiac surgery, and management in the postoperative period has rapidly advanced. This article summarizes the key concepts and literature in the care of the premature neonate with CHD.

[Predictors of extubation failure and reintubation in newborn infants subjected to mechanical ventilation]

Objective

To identify risk factors for extubation failure and reintubation in newborn infants subjected to mechanical ventilation and to establish whether ventilation parameters and blood gas analysis behave as predictors of those outcomes.

Methods

Prospective study conducted at a neonatal intensive care unit from May to November 2011. A total of 176 infants of both genders subjected to mechanical ventilation were assessed after extubation. Extubation failure was defined as the need to resume mechanical ventilation within less than 72 hours. Reintubation was defined as the need to reintubate the infants any time after the first 72 hours.

Results

Based on the univariate analysis, the variables gestational age <28 weeks, birth weight <1,000g and low Apgar scores were associated with extubation failure and reintubation. Based on the multivariate analysis, the variables length of mechanical ventilation (days), potential of hydrogen (pH) and partial pressure of oxygen (pO₂) remained associated with extubation failure, and the five-minute Apgar score and age at extubation were associated with reintubation.

Conclusion

Low five-minute Apgar scores, age at extubation, length of mechanical ventilation, acid-base disorders and hyperoxia exhibited associations with the investigated outcomes of extubation failure and reintubation.

Effects of sodium bicarbonate correction of metabolic acidosis on regional tissue oxygenation in very low birth weight neonates

OBJECTIVE

To determine the effects of sodium bicarbonate (NaHCO3) correction of metabolic acidosis on cardiopulmonary, laboratory, and cerebral, renal and splanchnic regional oxygen saturation (rSO2) and fractional tissue oxygen extraction (FTOE) in extremely premature neonates during the first postnatal week.

STUDY DESIGN

Observational cohort data were collected from 500 to 1250 g neonates who received NaHCO3 'half' corrections (0.3 * Weight (kg) * Base Deficit (mmol l(-1))) for presumed renal losses.

RESULT

Twelve subjects with normal blood pressure and heart rate received 17 NaHCO3 corrections. Mean (±s.d.) gestational age was 27±2 week and birth weight was 912±157 g. NaHCO3 corrections provided a mean (±s.d.) 4.5±1.0 ml kg(-1) fluid bolus, shifted mean (±s.d.) base deficit from 7.6±1.8 to 3.4±2.1 mmol l(-1) (P<0.05), and increased median (±s.d.) pH from 7.23±0.06 to 7.31±0.05 (P<0.05). No significant changes in blood pressure, pulse oximetry, PCO2, lactate, sodium, blood urea nitrogen, creatinine or hematocrit were observed. Cerebral, renal and splanchnic rSO2 (74%, 66% and 44%, respectively, at baseline) and FTOE (0.21, 0.29 and 0.52, respectively, at baseline) were unchanged following NaHCO3 correction.

CONCLUSION

NaHCO3 infusions decreased base deficits and increased pH though produced no discernible effects or benefits on cardiopulmonary parameters including rSO2 and FTOE. These findings warrant further prospective evaluation in larger populations with more significant metabolic acidosis to determine the utility of tissue oxygenation monitoring in differentiating metabolic acidosis due to oxygen delivery/consumption imbalance versus renal bicarbonate losses.

Extracorporeal Membrane Oxygenation in Pediatric Trisomy 21: 30 Years of Experience from the Extracorporeal Life Support Organization Registry

OBJECTIVES

To describe the use of extracorporeal membrane oxygenation (ECMO) in patients with trisomy 21 (T21), to identify risk factors for hospital mortality, and to compare outcomes with those of patients without T21.

STUDY DESIGN

Children under age 18 years registered in the Extracorporeal Life Support Organization Registry were included. Comparisons between patients with T21 and patients without T21 were performed using the χ(2) or Wilcoxon rank-sum test and multivariable logistic regression.

RESULTS

The study cohort included 623 patients with T21 and 46 239 patients without T21. The prevalence of T21 was 13.5/1000 patients receiving ECMO. ECMO utilization in patients with T21 increased over time, with 60% of cases occurring in the last decade. There was no significant difference in survival between patients without T21 and those with T21 (63% vs 57%; P = .23). In patients with T21, independent risk factors for mortality before cannulation were a cardiac indication for ECMO support and milrinone use (P ≤ .001 for both). Multivariable risk factors for mortality on ECMO included hemorrhagic, neurologic, renal, and pulmonary complications (P < .04 for all).

CONCLUSION

The use of ECMO in patients with T21 has increased over time. Patients with a cardiac indication for ECMO have higher mortality compared with those supported for respiratory indications. Despite differences in indications for ECMO, patients with T21 have similar hospital survival as those without T21; thus, by itself, a diagnosis of T21 should not be considered a risk factor for in-hospital mortality when contemplating ECMO cannulation.

Treatment options for lactic acidosis and metabolic crisis in children with mitochondrial disease

The mitochondrial pyruvate oxidation route is a tightly regulated process, which is essential for aerobic cellular energy production. Disruption of this pathway may lead to severe neurometabolic disorders with onset in early childhood. A frequent finding in these patients is acute and chronic lactic acidemia, which is caused by increased conversion of pyruvate via the enzyme lactate dehydrogenase. Under stable clinical conditions, this process may remain well compensated and does not require specific therapy. However, especially in situations with altered energy demands, such as febrile infections or longer periods of fasting, children with mitochondrial disorders have a high risk of metabolic decompensation with exacerbation of hyperlactatemia and severe metabolic acidosis. Unfortunately, no controlled studies regarding therapy of this critical condition are available and clinical outcome is often unfavorable. Therefore, the aim of this review was to formulate expert-based suggestions for treatment of these patients, including dietary recommendations, buffering strategies and specific drug therapy. However, it is important to keep in mind that a specific therapy for the underlying metabolic cause in children with mitochondrial diseases is usually not available and symptomatic therapy especially of severe lactic acidosis has its ethical limitations.

Metabolic acidosis in the first 14 days of life in infants of gestation less than 26 weeks

Extremely immature newborns develop a self-limiting normal anion gap metabolic acidosis in early life. This study examined the natural history of this acidosis in a population of infants of gestation less than 26 weeks in the first 14 days of life. The acidosis was maximal on day 4 with a mean base deficit of 10.6 mmol/l and had resolved in 90 % of infants by day 11. Dopamine usage was the only independent predictor of the acidosis. Its use was associated with a greater degree of acidosis.

CONCLUSION

Extremely preterm infants experience a self-limiting normal anion gap metabolic acidosis in the first 2 weeks of life which is consistent with renal tubular immaturity.

Comparative effectiveness and practice variation in neonatal care

Comparative effectiveness research (CER) is a relatively new term for clinical research that directly assists patients, clinicians, and policymakers in making informed decisions to improve health care. In neonatology, there are similarities and differences between CER and existing clinical research and quality improvement literature. This article uses existing examples in neonatal literature to describe CER methodology and list some future directions and challenges in neonatal CER.

Sodium bicarbonate therapy in patients with metabolic acidosis

Metabolic acidosis occurs when a relative accumulation of plasma anions in excess of cations reduces plasma pH. Replacement of sodium bicarbonate to patients with sodium bicarbonate loss due to diarrhea or renal proximal tubular acidosis is useful, but there is no definite evidence that sodium bicarbonate administration to patients with acute metabolic acidosis, including diabetic ketoacidosis, lactic acidosis, septic shock, intraoperative metabolic acidosis, or cardiac arrest, is beneficial regarding clinical outcomes or mortality rate. Patients with advanced chronic kidney disease usually show metabolic acidosis due to increased unmeasured anions and hyperchloremia. It has been suggested that metabolic acidosis might have a negative impact on progression of kidney dysfunction and that sodium bicarbonate administration might attenuate this effect, but further evaluation is required to validate such a renoprotective strategy. Sodium bicarbonate is the predominant buffer used in dialysis fluids and patients on maintenance dialysis are subjected to a load of sodium bicarbonate during the sessions, suffering a transient metabolic alkalosis of variable severity. Side effects associated with sodium bicarbonate therapy include hypercapnia, hypokalemia, ionized hypocalcemia, and QTc interval prolongation. The potential impact of regular sodium bicarbonate therapy on worsening vascular calcifications in patients with chronic kidney disease has been insufficiently investigated.

Neonatal renal physiology

The renal system plays a tremendous role in growth and development of infants and children. The kidney itself also undergoes a maturation process as it transitions from the fetal to the extrauterine environment. Renal function continues to undergo further adaptive changes in the neonatal period. It is important for the clinician caring for neonates to be aware of the expected fluid shifts, electrolyte handling, and renal functional capacity as these "normal" changes will become quite relevant when medical or surgical pathology is present. The preterm neonates are especially vulnerable due to their functionally immature kidneys. Renal function in the preterm neonate is not only immature at birth but there is a significant delay in the renal function to achieve its full capacity. This review highlights the physiologic adaptations of the kidney and its effects on the body during the neonatal period.

Sodium bicarbonate causes dose-dependent increases in cerebral blood flow in infants and children with single-ventricle physiology

BACKGROUND

Sodium bicarbonate (NaHCO3) is a common treatment for metabolic acidemia; however, little definitive information exists regarding its treatment efficacy and cerebral hemodynamic effects. This pilot observational study quantifies relative changes in cerebral blood flow (ΔrCBF) and oxy- and deoxyhemoglobin concentrations (ΔHbO2 and ΔHb) due to bolus administration of NaHCO3 in patients with mild base deficits.

METHODS

Infants and children with hypoplastic left heart syndrome (HLHS) were enrolled before cardiac surgery. NaHCO3 was given as needed for treatment of base deficit. Diffuse optical spectroscopies were used for 15 min postinjection to noninvasively monitor ΔHb, ΔHbO2, and ΔrCBF relative to baseline before NaHCO3 administration.

RESULTS

Twenty-two anesthetized and mechanically ventilated patients with HLHS (aged 1 d to 4 y) received a median (interquartile range) dose of 1.1 (0.8, 1.8) mEq/kg NaHCO3 administered intravenously over 10-20 s to treat a median (interquartile range) base deficit of -4 (-6, -3) mEq/l. NaHCO3 caused significant dose-dependent increases in ΔrCBF; however, population-averaged ΔHb and ΔHbO2 as compared with those of controls were not significant.

CONCLUSIONS

Dose-dependent increases in cerebral blood flow (CBF) caused by bolus administration of NaHCO3 are an important consideration in vulnerable populations wherein risk of rapid CBF fluctuations does not outweigh the benefit of treating a base deficit.

pH effects on cardiac function and systemic vascular resistance in preterm infants

OBJECTIVE

To investigate the effect of pH on cardiac function and systemic vascular resistance (SVR) in preterm infants.

STUDY DESIGN

In this prospective observational study, we evaluated hemodynamically stable, ≤ 30 weeks' gestation preterm infants during the first 2 postnatal weeks. Cardiac function was assessed by echocardiography at the time of arterial blood draw for clinically indicated blood gas analysis. Data were separately analyzed for the transitional (days 1-3) and post-transitional (days 4-14) periods.

RESULTS

We evaluated 147 pairs of arterial blood gases and echocardiograms in 29 preterm neonates (gestational age = 26.2 ± 1.5 weeks). Arterial pH ranged from 7.02-7.46. There was no linear relationship between pH and shortening fraction or stress-velocity index in transitional or post-transitional periods. We found a weak negative linear relationship between pH and left ventricular output and a positive linear relationship between pH and SVR only during the post-transitional period. These relationships were maintained after adjustment for the degree of base deficit. Arterial CO2 had effects similar to pH on myocardial function.

CONCLUSIONS

Unlike adults, myocardial contractility remains relatively unaffected by acidosis even at pH values close to 7.00 in hemodynamically stable preterm neonates during the first 2 postnatal weeks. However, as in adults, worsening acidosis in preterm neonates after the immediate transitional period is associated with a decrease in SVR along with an increase in left ventricular output. Thus, although myocardial contractility remains unaffected in preterm neonates during the first 2 postnatal weeks, the vascular response to acidosis undergoes a relatively rapid postnatal maturational process.

Management of renal dysfunction following term perinatal hypoxia-ischaemia

Acute kidney injury frequently develops following the term perinatal hypoxia-ischaemia. Quantifying the degree of acute kidney injury is difficult, however, as the methods currently in use are suboptimal. Acute kidney injury management is largely supportive with little evidence basis for many interventions. This review discusses management strategies and novel biomarkers that may improve diagnosis and management of renal injury following perinatal hypoxia-ischaemia.

CONCLUSION

Following perinatal hypoxia-ischaemia, acute kidney injury is common. Management of neonatal acute kidney injury is largely supportive. Novel acute kidney injury biomarkers may play a role in optimizing new categorical definitions of renal injury. Studies are needed to investigate the impact of neonatal acute kidney injury on long-term outcome.

Neonatal stabilization and postresuscitation care

Neonatal mortality is a major health care concern worldwide. Neonatal resuscitation alone does not address most causes of neonatal mortality; caregivers need to be trained in both neonatal resuscitation and stabilization. Neonatal stabilization requires caregivers to evaluate whether babies are at-risk or unwell, to decide what interventions are required, and to act on those decisions. Several programs address neonatal stabilization in a variety of levels of care in both well-resourced and limited health care environments. This article suggests a shift in clinical, educational, and implementation science from a focus on resuscitation to one on the resuscitation-stabilization continuum.

Infusing sodium bicarbonate suppresses hydrogen peroxide accumulation and superoxide dismutase activity in hypoxic-reoxygenated newborn piglets

Background

The effectiveness of sodium bicarbonate (SB) has recently been questioned although it is often used to correct metabolic acidosis of neonates. The aim of the present study was to examine its effect on hemodynamic changes and hydrogen peroxide (H₂O₂) generation in the resuscitation of hypoxic newborn animals with severe acidosis.

Methods

Newborn piglets were block-randomized into a sham-operated control group without hypoxia (n = 6) and two hypoxia-reoxygenation groups (2 h normocapnic alveolar hypoxia followed by 4 h room-air reoxygenation, n = 8/group). At 10 min after reoxygenation, piglets were given either i.v. SB (2 mEq/kg), or saline (hypoxia-reoxygenation controls) in a blinded, randomized fashion. Hemodynamic data and blood gas were collected at specific time points and cerebral cortical H₂O₂ production was continuously monitored throughout experimental period. Plasma superoxide dismutase and catalase and brain tissue glutathione, superoxide dismutase, catalase, nitrotyrosine and lactate levels were assayed.

Results

Two hours of normocapnic alveolar hypoxia caused cardiogenic shock with metabolic acidosis (pH: 6.99±0.07, HCO₃⁻: 8.5±1.6 mmol/L). Upon resuscitation, systemic hemodynamics immediately recovered and then gradually deteriorated with normalization of acid-base imbalance over 4 h of reoxygenation. SB administration significantly enhanced the recovery of both pH and HCO₃₋ recovery within the first hour of reoxygenation but did not cause any significant effect in the acid-base at 4 h of reoxygenation and the temporal hemodynamic changes. SB administration significantly suppressed the increase in H₂O₂ accumulation in the brain with inhibition of superoxide dismutase, but not catalase, activity during hypoxia-reoxygenation as compared to those of saline-treated controls.

Conclusions

Despite enhancing the normalization of acid-base imbalance, SB administration during resuscitation did not provide any beneficial effects on hemodynamic recovery in asphyxiated newborn piglets. SB treatment also reduced the H₂O₂ accumulation in the cerebral cortex without significant effects on oxidative stress markers presumably by suppressing superoxide dismutase but not catalase activity.

The use of chloride-sodium ratio in the evaluation of metabolic acidosis in critically ill neonates

Acid-base disturbances have been usually evaluated with the traditional Henderson-Hasselbach method and Stewart's physiochemical approach by quantifying anions of tissue acids (TA). It is hypothesized that an increase in tissue acids during metabolic acidosis would cause a compensatory decrease in the plasma chloride (Cl) relative to sodium (Cl-Na ratio) in order to preserve electroneutral balance. Therefore, we aimed to investigate the use of Cl-Na ratio as a bedside tool to evaluate the identifying raised TA in neonates as an alternative to complex calculations of Stewart's physiochemical approach. This retrospective study was conducted between January 2008 and December 2009. Infants were included in the study when blood gas analysis reveals a metabolic acidosis; pH <7.25 and sHCO(3) concentration was <22 mEq/L. The Cl-Na ratio, sodium-chloride difference (Diff(NaCl)), anion gap (AG), albumin-corrected AG (AG(corr)), strong ion difference (SID), unmeasured anions (UMA), and TA were calculated at each episode of metabolic acidosis. A total of 105 metabolic acidosis episodes occurred in 59 infants during follow-up. Hypochloremic metabolic acidosis occurred in 17 (16%) of samples, and all had increased TA. The dominant component of TA was UMA rather than lactate. There was a negative correlation between the Cl-Na ratio and SID, AG(corr), UMA, and TA. Also, there was a positive correlation between Diff(NaCl) and SID, AG(corr), UMA, and TA. Base deficit and actual bicarbonate performed poorly in identifying the TA. In conclusion, our study suggested that Diff(NaCl) and Cl-Na ratio are simple and fast, and may be an alternative method to complex Stewart's physiochemical approach in identifying raised UMA and TA in critically ill neonates.