Association between blood lactate and acid-base status and mortality in ventilated babies

Blood Lactate Levels during Therapeutic Hypothermia and Neurodevelopmental Outcome or Death at 18-24 Months of Age in Neonates with Moderate and Severe Hypoxic-Ischemic Encephalopathy

INTRODUCTION

Blood lactate levels in neonates with hypoxic-ischemic encephalopathy (HIE) vary, and their impact on neurodevelopmental outcome is unclear. We assessed blood lactate course over time in neonates with HIE during therapeutic hypothermia (TH) and investigated if blood lactate values were associated with neurodevelopmental outcome at 2 years of age.

METHODS

This is a retrospective cohort study of neonates with HIE born between 2013 and 2019, treated at the University Children's Hospital Zurich. We recorded blood lactate values over time and calculated time until lactate was ≤2 mmol/L. Neurodevelopmental outcome was assessed at 18-24 months of age using the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III), and categorized as favorable or unfavorable. We investigated associations between blood lactate values and outcome using logistic regression and adjusted for Sarnat stage.

RESULTS

33/45 neonates (69%) had a favorable and 14 (31%) an unfavorable neurodevelopmental outcome. Mean initial lactate values were lower in the favorable (13.9 mmol/L, standard deviation [SD]: 2.9) versus unfavorable group (17.1 mmol/L, SD 3.2; p = 0.002). Higher initial and maximal blood lactate levels were associated with unfavorable outcome, also when adjusted for Sarnat stage (adjusted odds ratio [aOR]: 1.37, 95% CI: 1.01-1.88, p = 0.046, and aOR: 1.35, 95% CI: 1.01-1.81, p = 0.041, respectively).

CONCLUSION

In neonates with HIE receiving TH, initial and maximal blood lactate levels were associated with neurodevelopmental outcome at 18-24 months of age, also when adjusted for Sarnat stage. Further investigations to analyze blood lactate as a biomarker for prognostic value are needed.

Association between Serum Lactate and Morbidity and Mortality in Neonates: A Systematic Review and Meta-Analysis

OBJECTIVE

Lactate is a marker of hypoperfusion in critically ill patients. Whether lactate is useful for identifying and stratifying neonates with a higher risk of adverse outcomes remains unknown. This study aimed to investigate the association between lactate and morbidity and mortality in neonates.

METHODS

A meta-analysis was performed to determine the association between blood lactate levels and outcomes in neonates. Ovid MEDLINE, EMBASE, Cochrane Library, and ClinicalTrials.gov were searched from inception to 1 May 2021. A total of 49 observational studies and 14 data accuracy test studies were included. The risk of bias was assessed using the Newcastle-Ottawa Scale for observational studies and the QUADAS-2 tool for data accuracy test studies. The primary outcome was mortality, while the secondary outcomes included acute kidney injury, necessity for renal replacement therapy, neurological outcomes, respiratory morbidities, hemodynamic instability, and retinopathy of prematurity.

RESULTS

Of the 3184 articles screened, 63 studies fulfilled all eligibility criteria, comprising 46,069 neonates. Higher lactate levels are associated with mortality (standard mean difference, -1.09 [95% CI, -1.46 to -0.73]). Using the estimated sensitivity (0.769) and specificity (0.791) and assuming a prevalence of 15% for adverse outcomes (median of prevalence among studies) in a hypothetical cohort of 10,000 neonates, assessing the lactate level alone would miss 346 (3.46%) cases (false negative) and wrongly diagnose 1776 (17.76%) cases (false positive).

CONCLUSIONS

Higher lactate levels are associated with a greater risk of mortality and morbidities in neonates. However, our results do not support the use of lactate as a screening test to identify adverse outcomes in newborns. Research efforts should focus on analyzing serial lactate measurements, rather than a single measurement.

Can lactate be valuable in early diagnosis and prognosis of neonatal sepsis?

Background

Sepsis monitoring tissue perfusion is crucial for detecting circulatory failure early, implementing the right treatments, and assessing response. Insufficient oxygenation leads to a rise in lactate level and has been shown to be useful in predicting mortality and morbidity in newborns. There have not been many studies on how lactate measurement affects neonatal sepsis diagnosis and prognosis.

Aim

The aim of our study was to determine the impact of lactate on early diagnosis and prognosis in neonatal sepsis.

Materials and Methods

Eighty-seven newborns diagnosed with neonatal sepsis at a neonatal intensive care unit between January 2010 and July 2021 were included in the study. Venous blood gas, lactate, and C-reactive protein (CRP) levels and complete blood count on the first, second, and third day of hospitalization were noted. Lactate values were correlated with other variables to determine the impact of hyperlactatemia on morbidity and to determine factors affecting the length of stay. IBM SPSS Statistics version 22.0 for Windows was used to analyze the data (SPSS Inc., Chicago, IL, United States).

Results

A strong negative correlation between lactate and oxygenation and perfusion indicators (HCO3, BE, PaO2) during the therapeutic process was observed. With treatment, the initial measured lactate value decreased, and a significant increase in CRP and oxygen saturation was observed, which was interpreted as the observation of an early lactate response to infection before a CRP response. The initial lactate level, as well as the change in lactate levels, was not, however, significantly correlated with the length of stay.

Conclusion

Lactate can be used in the early diagnosis of neonatal sepsis and for determining prognosis.

Nomogram for predicting fulminant necrotizing enterocolitis

BACKGROUND

Fulminant necrotizing enterocolitis (FNEC) is the most serious subtype of NEC and has a high mortality rate and a high incidence of sequelae. Onset prediction can help in the establishment of a customized treatment strategy. This study aimed to develop and evaluate a predictive nomogram for FNEC.

METHODS

We conducted a retrospective observation to study the clinical data of neonates diagnosed with NEC (Bell stage ≥ IIB). Neonates were divided into the FNEC and NEC groups. A multivariate logistic regression model was used to construct the nomogram model. The performance of the nomogram was assessed using area under the curve, calibration analysis, and decision curve analysis.

RESULTS

A total of 206 neonate cases were included, among which 40 (19.4%) fulfilled the definition of FNEC. The identified predictors were assisted ventilation after NEC onset; shock at NEC onset; feeding volumes before NEC onset; neutrophil counts on the day of NEC onset; and neutrophil, lymphocyte, and monocyte counts on day 1 after NEC onset. The nomogram exhibited good discrimination, with an area under the receiver operating characteristic curve of 0.884 (95% CI 0.825-0.943). The predictive model was well calibrated. Decision curve analysis confirmed the clinical usefulness of this nomogram.

CONCLUSION

A nomogram with a potentially effective application was developed to facilitate the individualized prediction of FNEC, with the hope of providing further direction for the early diagnosis of FNEC and timing of intervention.

Multimodal Assessment of Systemic Blood Flow in Infants

The assessment of systemic blood flow is a complex and comprehensive process with clinical, laboratory, and technological components. Despite recent advancements in technology, there is no perfect bedside tool to quantify systemic blood flow in infants that can be used for clinical decision making. Each option has its own merits and limitations, and evidence on the reliability of these physiology-based assessment processes is evolving. This article provides an extensive review of the interpretation and limitations of methods to assess systemic blood flow in infants, highlighting the importance of a comprehensive and multimodal approach in this population.

Lactate, Base Excess, and the Pediatric Index of Mortality: Exploratory Study of an International, Multicenter Dataset

OBJECTIVES

To investigate the relationship between ICU admission blood lactate, base excess, and ICU mortality and to explore the effect of incorporating blood lactate into the Pediatric Index of Mortality.

DESIGN

Retrospective cohort study based on data prospectively collected on every PICU admission submitted to the U.K. Pediatric Intensive Care Audit Network and to the Australia and New Zealand Pediatric Intensive Care Registry.

SETTING

Thirty-three PICUs in the United Kingdom/Republic of Ireland and nine PICUs and 20 general ICUs in Australia and New Zealand.

PATIENTS

All ICU admissions between January 1, 2012, and December 31, 2015.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

One hundred twenty-three thousand two hundred fifty-two admissions were recorded in both datasets; 81,576 (66.2%) in the United Kingdom/Republic of Ireland and 41,676 (33.8%) in Australia and New Zealand. Of these 75,070 (61%) had a base excess recorded, 63,316 (51%) had a lactate recorded, and 60,876 (49%) had both base excess and lactate recorded. Median lactate value was 1.5 mmol/L (interquartile range, 1-2.4 mmol/L) (United Kingdom/Republic of Ireland: 1.5 [1-2.5]; Australia and New Zealand: 1.4 [1-2.3]). Children with a lactate recorded had a higher illness severity, were more likely to be invasively ventilated, admitted after cardiac surgery, and had a higher mortality rate, compared with admissions with no lactate recorded (p < 0.001). The relationship between lactate and mortality was stronger (odds ratio, 1.32; 95% CI, 1.31-1.34) than between absolute base excess and mortality (odds ratio, 1.13; 95% CI, 1.12-1.14). Addition of lactate to the Pediatric Index of Mortality score led to a small improvement in performance over addition of absolute base excess, whereas adding both lactate and absolute base excess achieved the best performance.

CONCLUSIONS

At PICU admission, blood lactate is more strongly associated with ICU mortality than absolute base excess. Adding lactate into the Pediatric Index of Mortality model may result in a small improvement in performance. Any improvement in Pediatric Index of Mortality performance must be balanced against the added burden of data capture when considering potential incorporation into the Pediatric Index of Mortality model.

Recognition and Management of Cardiovascular Insufficiency in the Very Low Birth Weight Newborn

The measurement of blood pressure in the very low birth weight newborn infant is not simple and may be erroneous because of numerous factors. Assessment of cardiovascular insufficiency in this population should be based on multiple parameters and not only on numeric blood pressure readings. The decision to treat cardiovascular insufficiency should be made after considering the potential complications of such treatment. There are numerous potential strategies to avoid or mitigate hypoperfusion states in the very low birth weight infant.

Serum troponin I: a potential biomarker of hypoxic-ischemic encephalopathy in term newborns

OBJECTIVE

This study was intended to evaluate the predictive values of serum procalcitonin (PCT), lactate, creatine kinase (CK-MB), and troponin I on the diagnosis and staging of neonatal hypoxic-ischemic encephalopathy (HIE).

MATERIALS AND METHODS

We retrospectively retrieved data from electronic medical records at our children's hospital, and we included all term newborns admitted between December 2018 and June 2020 with features of perinatal asphyxia. Receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to measure and evaluate the predictive values of biomarkers. p values < 0.05 were set as statistical significance.

RESULTS

A total of 201 neonates were included. They were grouped as control (n = 40), mild HIE (n = 105), moderate HIE (n = 36), and severe HIE (n = 20). Serum lactate, PCT, CK-MB, and troponin I levels in severe hypoxic-ischemic brain injury group were significantly higher than those in mild to moderate hypoxic-ischemic brain injury group and control group (p < 0.05). Based on ROC and AUC analysis, troponin I showed highest predictive ability with AUC of 0.904, and sensitivity and specificity of 95.00% and 87.50% respectively.

CONCLUSION

Serum troponin I has a good predictive value for neonatal hypoxic-ischemic encephalopathy after perinatal asphyxia.

Baseline Values of Left Ventricular Systolic Function in Preterm Infants With Septic Shock: A Prospective Observational Study

BACKGROUND AND AIM

Guidelines recommended that cardiac index (CI) of term infants with septic shock should reach the target level of 3.3-6.0L/(min⋅m²). However, there are still no standard values for preterm infants with septic shock. Herein, we investigated the functional echocardiographic baseline values of left ventricular (LV) systolic functional parameters at the onset of septic shock in preterm infants and possible correlations between baseline values and poor outcomes.

MATERIALS AND METHODS

This was a prospective, observational, and longitudinal single-center study. Eligible infants were monitored for LV systolic functional parameters using functional echocardiography at the onset of septic shock. The primary study outcome was the difference in the baseline value of LV systolic functional parameters in preterm infants with septic shock with different gestational age (GA) and birth weight (BW). The secondary outcome was septic shock-associated death or severe brain injury (including grade 3-4 intraventricular hemorrhage or periventricular leukomalacia).

RESULTS

In total, 43 subjects met the criteria, with a median GA of 32^1/7 weeks and BW of 1800 grams. No difference was observed in baseline values of LV systolic functional parameters among infants with different GA and BW. Infants were assigned to good and poor outcomes groups based on septic shock-associated death or severe brain injury. Out of 43 infants, 29 (67.4%) had good outcomes vs. 14 (32.6%) with poor outcomes. Stroke index (SI) [18.2 (11.1, 18.9) mL/m² vs. 23.5 (18.9, 25.8) mL/m², p = 0.017] and cardiac index (CI)[2.7 (1.6, 3.5) L/(min⋅m²) vs. 3.4 (3.0, 4.8) L/(min⋅m²), p = 0.015] in infants with poor outcomes were significantly lower (P < 0.05). Receiver operating characteristic (ROC) curve analysis showed that the cut-off values of SI and CI for predicting poor outcomes in preterm infants with septic shock were 19.5 mL/m² (sensitivity, 73.9%; specificity, 81.8%) and 2.9L/(min⋅m²) (sensitivity, 78.3%; specificity, 72.7%), with area under the ROC curve (AUC) value of 0.755 and 0.759, respectively.

CONCLUSION

There were no differences in baseline LV systolic functional values among preterm infants with septic shock with different GA and BW. However, preterm infants with SI<19.5mL/m² and/or CI<2.9L/(min⋅m²) at the onset of septic shock were at high risk of having poor outcomes.

Neonatal Impedance Cardiography in Asphyxiated Piglets-A Feasibility Study

OBJECTIVES

Impedance cardiography (ICG) is a non-invasive method for continuous cardiac output measurement and has the potential to improve monitoring and treatment of sick neonates. PhysioFlow^® is a signal-morphology ICG-system showing promising results in adults with low and high cardiac output, but no data from neonates or neonatal models exist. The aim of this study was to investigate PhysioFlow^® feasibility in asphyxiated newborn piglets.

METHODS

Fifteen piglets, under continuous arterial heart rate (HR) and blood pressure (BP) monitoring, were asphyxiated until asystole. Cardiopulmonary resuscitation was performed and the piglets monitored after return of spontaneous circulation (ROSC). Arterial lactate was measured at baseline, every 5 min throughout asphyxiation, at asystole, and at 10 min and later every 30 min after ROSC. PhysioFlow^® measured cardiac stroke volume (SV) and HR, and calculated cardiac index (CI) (L/m²/min). Registrations with a signal quality < 75% were excluded, and registrations recorded for 30 min from start of asphyxia analyzed. Pearson correlations were calculated for CI; and HR, mean BP and blood lactate.

RESULTS

The piglets were asphyxiated for median (interquartile range) 30 (20-35) min and had a lactate at asystole of 15.0 (9.1-17.0) mmol/L. Out of a total of 20.991 registrations in all animals combined, there were 10.148 (48.3%) registrations with a signal quality ≥ 75%. Signal quality ≥ 75% varied in individual piglets from 7 to 82% of registrations. We analyzed 1.254 registrations recorded 30 min from initiation of asphyxia, i.e., in piglets with brief asphyxia times, this included cardiopulmonary resuscitation and post-ROSC observation. There was a positive correlation between CI and SVI (r = 0.90, p < 0.001), and between CI and HR (r = 0.446, p < 0.001). There was no correlation between CI, or mean BP or lactate (p = 0.98 and 0.51, respectively).

CONCLUSION

About half of ICG-registrations in asphyxiated piglets were of good quality. However, signal quality was highly variable between piglets. In total, there was a higher proportion of reliable ICG-registrations than reported from clinical delivery room studies using electrical velocimetry. Our data are physiologically plausible and supports further research evaluating PhysioFlow^® for cardiac output monitoring in perinatal asphyxia. In particular, factors influencing inter-individual variations in signal quality should be explored.

Perioperative Hypothermia in Children

Background: First described by paediatric anaesthesiologists, perioperative hypothermia is one of the earliest reported side effects of general anaesthesia. Deviations from normothermia are associated with numerous complications and adverse outcomes, with infants and small children at the highest risk. Nowadays, maintenance of normothermia is an important quality metric in paediatric anaesthesia. Methods: This review is based on our collection of publications regarding perioperative hypothermia and was supplemented with pertinent publications from a MEDLINE literature search. Results: We provide an overview on perioperative hypothermia in the paediatric patient, including definition, history, incidence, development, monitoring, risk factors, and adverse events, and provide management recommendations for its prevention. We also summarize the side effects and complications of perioperative temperature management. Conclusions: Perioperative hypothermia is still common in paediatric patients and may be attributed to their vulnerable physiology, but also may result from insufficient perioperative warming. An effective perioperative warming strategy incorporates the maintenance of normothermia during transportation, active warming before induction of anaesthesia, active warming during anaesthesia and surgery, and accurate measurement of core temperature. Perioperative temperature management must also prevent hyperthermia in children.

Acute Kidney Injury in Neonates with Perinatal Asphyxia Receiving Therapeutic Hypothermia

OBJECTIVE

To assess the incidence and severity of acute kidney injury (AKI) and evaluate risk factors that predict AKI in asphyxiated infants receiving therapeutic hypothermia.

STUDY DESIGN

Infants ≥36 weeks' gestation diagnosed with moderate-to-severe perinatal asphyxia and received therapeutic hypothermia were reviewed retrospectively (n = 166). Modified Acute Kidney Injury Network criteria were used to diagnose AKI. The results of infants with AKI were compared with the infants who did not develop AKI.

RESULTS

AKI developed in 49 (29.5%) infants, of whom 22 had stage I, 13 had stage II, and 14 had stage III AKI. The overall mortality rate was 15.7% and was significantly higher in infants with AKI when compared with infants without AKI (41 vs. 5%; p < 0.001). Asystole at birth (p = 0.044), placental abruption (p = 0.041), outborn status (p = 0.041), need for vasopressor support (p = 0.031), increased bleeding tendency (p = 0.031), initial lactate level (p = 0.015), and 12-hour lactate level (p = 0.029) were independent risk factors for the development of AKI. Receiver operating characteristic curve analysis demonstrated a good predictive value for initial lactate level (>15 mmol/L), with 69% sensitivity (95% CI: 55-82) and 82% specificity (95% CI: 74-89), and for 12-hour lactate level (>6 mmol/L), with 83.7% sensitivity (95% CI: 70-93) and 73.5% specificity (95% CI: 64.5-81), to predict AKI.

CONCLUSION

AKI is still a common complication of perinatal asphyxia despite treatment with therapeutic hypothermia. Identification of risk factors associated with the development of AKI in asphyxiated infants would be potentially beneficial to reduce morbidity and mortality. Besides perinatal risk factors, initial and 12-hour lactate concentrations can be used for the early prediction of AKI.

Plethysmography variability index (PVI) changes in preterm neonates with shock-an observational study

Shock is an acute state of circulatory dysfunction. The diagnosis of shock is complex in neonates. The relative sensitivity of current clinical or laboratory findings for detecting shock is largely unknown, especially for preterm neonates. For preload assessment, inferior vena cava (IVC) collapsibility can be a useful bedside echocardiography parameter. plethysmography variability index (PVI) is a marker of fluid responsive shock in adults and children, but not well defined in neonates. In this prospective observational study, we evaluated the changes in PVI in preterm neonates with shock. Among the 37 infants enrolled in the study, the mean blood pressure (MAP) was 45 (± 4 mm of Hg) and none of infants had hypotension. The mean pulse pressure was 28 mm of Hg, the mean PVI was 28% (±5), the mean arterial blood gas pH was 7.20 (±0.07), and the mean base deficit was 9.9 (±2.53) at the onset of shock. Thirty (96.77%) of the 31 infants with resolution of shock showed decrease in PVI with an average decrease of 11% (±5).Conclusion: Significant proportion of neonates show an increase in PVI at the onset of shock. What is Known: • Plethysmography Variability Index (PVI) is commonly used as a marker of volume status in paediatric population. • Changes in PVI may guide in giving volume boluses in patients with shock. What is New: • This study provides information of changes in PVI in preterm neonates with shock. • PVI may become a valuable tool to be used at bedside in preterm infants with shock.

Evaluation of urine output, lactate levels and lactate clearance in the transitional period in very low birth weight preterm infants

OBJECTIVE

To assess the association between urine output (UO), arterial lactate levels (LL) and lactate clearance with haemodynamic instability and death in very low birth weight (VLBW) preterm in the transitional period.

STUDY DESIGN

Retrospective cohort study with VLBW newborns born in 2016 and 2017, excluding those with malformations and without data. We evaluated 254 preterm infants with a total of 482 lactate levels measured in the first 72 h. Areas under the curve (AUC) were calculated for receiver-operator characteristics (ROC) curves of UO and LL (alone and combined) and of lactate clearance for prediction of haemodynamic instability and death.

RESULTS

All AUC were below 0.80. Sensitivity and specificity were also not very good. Although patients with poor outcomes had lactate levels higher than those with good outcomes, discrimination was poor.

CONCLUSION

UO and LL and lactate clearance were not good predictors of haemodynamic instability or death within 10 days of life. What is Known • It is already established that blood pressure is not a good marker for haemodynamic stability in the preterm infant. • Others clinical parameters, albeit are largely used, are not fully reliable as well. What is New • In our study we tried to determine the sensibility and specificity of urine output and arterial lactate and also the lactate clearance. • All AUC were below 0.80. Sensitivity and specificity were also not very good. Although patients with poor outcomes had lactate levels higher than those with good outcomes, discrimination was poor.

Echocardiographic assessment of hemodynamic changes in preterm neonates with shock: a prospective pragmatic cohort study

Shock is a state of circulatory dysfunction and its diagnosis is complex in neonates. Hemodynamic assessment using echocardiography has potential to guide better management regimes in neonates with shock. Objective of this study is to analyze changes in the echocardiographic parameters in preterm neonates with shock at presentation and after resolution. In this prospective pragmatic Cohort study, eligible neonates with shock were monitored for changes in echocardiographic parameters at onset of shock and after resolution of shock. Paired data analysis was done for observed changes in the parameters. Based on initial clinical parameters and echocardiographic parameters, infants were assigned into different types of shock. Data of 37 infants were analyzed for baseline clinical and echocardiographic parameters, and data of 31 infants were analyzed for the changes in the observed parameters after shock resolution. Statistically significant changes were observed in inferior vena cava collapsibility index (ICI), left ventricular end diastolic volume (LVEDV), isovolemic ventricular relaxation time (IVRT), left and right ventricular stroke volume, and ejection fraction (EF). There was no agreement between clinical and echocardiographic definitions of shock.Conclusion: We noticed shock has overlapping pathophysiologic features. Our study highlights the importance of baseline documentation of echocardiographic parameters of all infants who are at risk of shock and repeat echocardiography at onset of shock to observe the changes in ICI, LVEDV, IVRT, stroke volume, and EF. This would guide pathophysiological management of shock in neonates. What is Known: • In neonates pathophysiology of shock is overlapping. • Echocardiography can help in better understanding and management of shock. What is New: • Study gives median changes in major echocardiographic parameters in neonatal shock. • These changes can guide for selection of volume and inotropes in management.

Lactate levels and clearance rate in neonates undergoing mechanical ventilation in Tibet

Objective

This study aimed to examine the characteristics of blood lactate in neonates undergoing mechanical ventilation in Tibet.

Methods

We recruited 67 neonates undergoing mechanical ventilation in Naqu People’s Hospital as the plateau observation group and 94 neonates undergoing mechanical ventilation in Shengjing Hospital as the control group. We analyzed the differences in lactate levels between the two groups.

Results

The lactate clearance rates of neonates with asphyxia and those with respiratory distress syndrome were significantly lower in the plateau group than in the control group. Lactate levels in neonates who died in the plateau group were significantly higher and the lactate clearance rate was significantly lower than those in neonates who survived. The cut-off point for the lactate clearance rate at 6 hours for predicting mortality was 6.09% in the plateau group.

Conclusion

The lactate clearance rate of neonates on mechanical ventilation in the plateau area is lower than that in neonates in the non-plateau area. The lactate clearance rate at 6 hours is important for evaluating the prognoses of critical neonates in plateau areas.

Assessment of neonatal perfusion

Disorders of perfusion in newborn infants are frequently observed in neonatal intensive care units. The current assessment practices are primarily based on clinical signs. Significant technologic advances have opened new avenues for continuous assessment at the bedside. Combining these devices with functional echocardiography provides an in-depth understanding of perfusion and allows targeting therapy to the pathophysiology rather than monitoring and targeting blood pressure. This change in approach is guided by the fact that perfusion disorders can result from a number of causes and a single management approach might do more harm than good. This approach has the potential to improve long term outcomes but needs to be tested in well-designed trials.

Left ventricular ejection fraction using manual and semi-automated biplane method of discs in very preterm infants

BACKGROUND

Biplane left ventricular ejection fraction (LVEF) is a valuable echocardiographic parameter for assessment of LV systolic pump efficiency in adults and children, but not often reported in preterm infants. The primary aim of this study was to longitudinally measure biplane LVEF in very preterm infants during the neonatal intensive care period. Secondary aim was to compare manual and semi-automatic determination of LVEF for agreement and variability.

METHODS

Stable preterm infants less than 30 weeks gestation were scanned on day 3, day 28, and at 36 weeks postmenstrual age. The LV endocardium was traced manually and semi-automatically using integrated speckle tracking software in apical 4-chamber and apical 3-chamber images to obtain end-diastolic volume and end-systolic volume, and calculate LVEF. Agreement between methods and variability within and between observers was determined using an interclass correlation coefficient (ICC) and Bland-Altman analysis.

RESULTS

Sixty-six preterm infants with a mean birth weight of 1100 (239) g were analyzed. The average manual biplane LVEF was 58 (3)%, 59 (3)%, and 55 (4)% at the three respective time points. Manual LVEF showed good agreement with semi-automatic LVEF (ICC 0.76) with a small bias of -1.5 (3.0)%. Interobserver variability of LVEF improved with semi-automatic tracing of the LV endocardial border (ICC manual 0.68 vs semi-automatic 0.80).

CONCLUSION

Left ventricular systolic pump efficiency in preterm infants remains stable during the neonatal intensive care period. Semi-automatic biplane LVEF has less interobserver variability and can be used interchangeably with manual biplane LVEF.

Plasma lactate can improve the accuracy of the Pediatric Sequential Organ Failure Assessment Score for prediction of mortality in critically ill children: A pilot study

BACKGROUND

Plasma lactate has been used to predict the prognosis of critically ill children, but mortality risk scores appear to be more appealing, particularly in resource-limited countries.

OBJECTIVE

To assess the prognostic utility of lactate compared with the pediatric Sequential Organ Failure Assessment (pSOFA) score among the general pediatric intensive care unit (PICU) population.

METHODS

This was a prospective observational study including 78 children admitted to a tertiary-level PICU. Plasma lactate was measured upon admission and repeated 24h later. pSOFA score, Pediatric Risk of Mortality, and Pediatric Index of Mortality-2 (PIM2) were calculated. The primary outcome was 30-day mortality.

RESULTS

In total, 47.4% of patients had hyperlactatemia at admission. Among these, 20.5% had persistent hyperlactatemia. No significant difference in admission lactate level was found between survivors and nonsurvivors. The 24-h, peak, and average lactate levels were higher among nonsurvivors (P=0.005, 0.035, and 0.019, respectively). The 24-h lactate level and pSOFA score were independent predictors of mortality (adjusted odds ratio and 95% confidence interval=1.12 [1.02-1.23] and 1.80 [1.23-2.64], respectively]. The 24-h lactate level showed positive correlations with pSOFA, PRISM, and PIM2 (Spearman correlation coefficient=0.31, 0.23, 0.43; P=0.006, P=0.047, P<0.001, respectively). The 24-h lactate level had an area under the receiver operating characteristic curve (AUC) of 0.77 (P=0.013) for mortality prediction, while admission, peak, and average lactate level had an AUC of 0.69, 0.69, 0.71 (P=0.086, P=0.035, P=0.019), respectively. PIM2, PRISM, and pSOFA score had an AUC of 0.80, 0.78, 0.82 (P=0.001, P=0.001, and P<0.001), respectively. Combining 24-h lactate level with pSOFA demonstrated superior performance (AUC=0.88).

CONCLUSION

Both 24-h lactate level and pSOAF are useful for prediction of mortality. Incorporating the 24-h lactate level into the pSOFA Score achieved superior prognostic utility.

Marked variability in intrapartum electronic fetal heart rate patterns: association with neonatal morbidity and abnormal arterial cord gas

OBJECTIVE

Investigate marked variability in fetal heart rate (FHR) patterns before delivery and its association with neonatal morbidity and abnormal arterial cord gases.

STUDY DESIGN

Prospective cohort of laboring patients at term. Composite neonatal morbidity (respiratory distress, mechanical ventilation, suspected sepsis, meconium aspiration syndrome, therapeutic hypothermia, hypoxic-ischemic encephalopathy, seizure, and death) and abnormal arterial cord gases (pH < 7.10, lactate ≥ 4 mmol/L, base deficit < -12 mEq/L) were assessed with multivariable logistic regression.

RESULT

Three hundred and ninety (4.5%) neonates had marked variability in FHR patterns before delivery. There was no difference in composite neonatal morbidity (aRR 1.22; 95% CI 0.91-1.63), though neonates with marked variability in FHR patterns were more likely to have a respiratory distress (aRR 1.85; 95% CI 1.25-2.70). There was an increased risk of composite abnormal arterial cord gases (aRR 1.66; 95% CI 1.47-1.88).

CONCLUSION

Marked variability in FHR patterns was not associated with composite neonatal morbidity but was associated with abnormal arterial cord gases.

Using Platelet Parameters to Anticipate Morbidity and Mortality Among Preterm Neonates: A Retrospective Study

Background: Platelets participate in many physiological and pathological functions and some platelet parameters predict adult diseases. However, few studies report whether platelet parameters may reflect neonatal disease and mortality in a large cohort. Objective: We aimed to investigate whether platelet parameters could predict bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), intraventricular hemorrhage (IVH), and NICU mortality. Study Design and Methods: This retrospective cohort study examined records from 2006 to 2017 at the neonatal intensive care unit (NICU) of Fukushima Medical University Hospital. We retrospectively investigated platelet count, plateletcrit (PCT), mean platelet volume (MPV), and platelet distribution width (PDW) on the first day of life in preterm newborns born <32 weeks' gestation admitted to our NICU from 2006 to 2017. Receiver operating characteristic (ROC) and multiple regression analyses, along with Cox proportional hazard modeling, identified independent predictors of morbidities and mortality in preterm newborns. Results: Of 1,501 neonates admitted to our NICU, a total of 305 preterm newborns were included in this study. Gestational age, birth weight, and Apgar score were significantly lower in non-survivors than in survivors. Platelet count, PCT, PDW and PMI did not differ significantly between the two groups, whereas mean MPV in non-survivors was significantly higher than in survivors (10.5 fl vs. 10.0 fl, p = 0.001). Multivariate Cox hazard modeling showed that shorter GA [HR: 0.628, 95% CI: 0.464-0.840, p = 0.003], male sex [HR: 0.269, 95% CI: 0.113-0.640, p = 0.001], and MPV [HR: 1.469, 95% CI: 1.046-2.063, p = 0.026] independently predicted overall survival. Per receiver operating curve, an MPV threshold of 10.2 fl. MPV predicts prognosis in neonates with a sensitivity of 72.4% and a specificity of 58.6% (AUC = 0.685, 95% CI: 0.600-0.789, p = 0.001). Furthermore, multivariate analysis revealed that platelet parameters were not associated with BPD and NEC, whereas small for gestational age (SGA), Apgar score at 5 min, and low PCT were associated with intraventricular hemorrhage (IVH). Conclusion: This study demonstrates that low PCT predicts IVH, and MPV ≥ 10.2 fL correlates with mortality among infants born after <32 weeks' gestation.

Factors affecting the differentiation of the Apgar score and the biochemical correlation of fetal well-being - a prospective observational clinical study

OBJECTIVE

Objective: The purpose of the study was to identify the features of both the labor and the assisting physicians when evaluating the newborn according to the Apgar score and how these correlate with the biochemical markers of fetal well-being in order to make the Apgar score more objective.

PATIENTS AND METHODS

Material and methods: A prospective observational clinical study conducted in a 3rd reference level center between 1st April 2014 and 31st March 2015. The study enrolled 17 neonatologists and 1527 term newborns.

RESULTS

Results: The Apgar score is highest after natural vaginal delivery, lower after instrumental labor (p <0.001). The pH of the umbilical cord blood and lactate concentration correlate better with a high score than with a lowered one. The young age of a physician does not reduce Apgar score reliability. There were no differences in Apgar assessment according to physicians' training and the time of labor. There were no correlations between abnormalities in postnatal central nervous system ultrasound and the Apgar score.

CONCLUSION

Conclusion: Biochemical tests of umbilical cord blood significantly increase the Apgar score reliability.

Lactate acidosis and cardiac output during initial therapeutic cooling in asphyxiated newborn infants

Aim

We hypothesized that compromised cardiac output in asphyxiated infants may influence on the rate of disappearance of lactate due to insufficient perfusion.

Methods

The study was a prospective, observational study, where infants with perinatal asphyxia who met the criteria for therapeutic hypothermia were included. Cardiac output, stroke volume and heart rate were measured by electrical velocimetry in 15 newborn infants with perinatal asphyxia during the first six hours of active therapeutic hypothermia. Results from routine blood samples were collected retrospectively. Cardiac parameters were also measured in 10 healthy, term infants after caesarian section. Cardiac parameters were compared between the asphyxiated group and the control group prior to and during hypothermia. Rate of disappearance of lactate was correlated to cardiac output in the asphyxiated infants.

Results

Cardiac output was stable in the healthy infants from 0.5 to 6 hours postnatally. The infants with perinatal asphyxia had lower cardiac output prior to and during therapeutic hypothermia compared to the control group. Rate of disappearance of lactate was not related to cardiac output.

Conclusion

An association between disappearance of lactate acidosis and low cardiac output was not confirmed. A low rate of disappearance of lactate may rather be an indicator of organ injury due to asphyxia.

Validity of Biomarkers of Early Circulatory Impairment to Predict Outcome: A Retrospective Analysis

Objectives: The definition of circulatory impairment in the premature infant is controversial. Current research suggests overdiagnosis and overtreatment. We aimed to analyse which biomarkers move clinicians to initiate cardiovascular treatment (CVT). The prognostic capacity for adverse outcome (death and/or moderate-severe brain damage by cranial ultrasound at term equivalent) of these biomarkers was evaluated. Study Design: Retrospective data analysis from preterm infants enrolled in a placebo-controlled trial on dobutamine for low superior vena cava (SVC) flow, who showed normal SVC flow within the first 24 h (not randomized). Five positive biomarkers were considered: MABP < gestational age (GA)-1 mmHg; MABP < GA-5 mmHg; lactate > 4 mmol/L; BE < -9 mmol/L; SVC flow <51 ml/kg/min. Results: Ninety eight infants formed the study cohort. Thirty six received CVT (2-95 h). Logistic regression models adjusted for gestational age showed a positive association between CVT and the risk of death or moderate-severe abnormal cranial ultrasound at term equivalent [(OR 5.2, 95%CI: 1.8-15.1) p = 0.002]. MABP < GA-1 mmHg and lactate > 4 mmol/L were the most prevalent biomarkers at start of treatment. Low BE, high serum lactate and low SVC flow at first echocardiography showed a trend toward being associated with adverse outcome, although not statistically significant. Conclusions: Low blood pressure and high lactate are the most prevalent biomarkers used for CVT prescription. Lactic acidosis and low SVC flow early after birth showed a trend toward being associated with adverse outcome. These findings support using a combination of biomarkers for inclusion in a placebo-controlled trial on CVT during transitional circulation.

Factors affecting the differentiation of the Apgar score and the biochemical correlation of fetal well-being - a prospective observational clinical study

OBJECTIVE

Objective: The purpose of the study was to identify the features of both the labor and the assisting physicians when evaluating the newborn according to the Apgar score and how these correlate with the biochemical markers of fetal well-being in order to make the Apgar score more objective.

PATIENTS AND METHODS

Material and methods: A prospective observational clinical study conducted in a 3rd reference level center between 1st April 2014 and 31st March 2015. The study enrolled 17 neonatologists and 1527 term newborns.

RESULTS

Results: The Apgar score is highest after natural vaginal delivery, lower after instrumental labor (p <0.001). The pH of the umbilical cord blood and lactate concentration correlate better with a high score than with a lowered one. The young age of a physician does not reduce Apgar score reliability. There were no differences in Apgar assessment according to physicians' training and the time of labor. There were no correlations between abnormalities in postnatal central nervous system ultrasound and the Apgar score.

CONCLUSION

Conclusion: Biochemical tests of umbilical cord blood significantly increase the Apgar score reliability.

The Pathophysiology of Low Systemic Blood Flow in the Preterm Infant

Assessment and treatment of the VLBW infant with cardiovascular impairment requires understanding of the underlying physiology of the infant in transition. The situation is dynamic with changes occurring in systemic blood pressure, pulmonary pressures, myocardial function, and ductal shunt in the first postnatal days. New insights into the role of umbilical cord clamping in the transitional circulation have been provided by large clinical trials of early versus later cord clamping and a series of basic science reports describing the physiology in an animal model. Ultrasound assessment is invaluable in assessment of the physiology of the transition and can provide information about the size and shunt direction of the ductus arteriosus, the function of the myocardium and its filling as well as measurements of the cardiac output and an estimate of the state of peripheral vascular resistance. This information not only allows more specific treatment but it will often reduce the need for treatment.

Inotropes for preterm babies during the transition period after birth: friend or foe?

During the transition to extrauterine life, preterm infants are at high risk of developing circulatory failure. Currently, hypotension is used as major diagnostic criteria for starting treatments such as fluid boluses, inotropes or steroids. Most of these treatment options have not been studied in large randomised controlled trials for efficacy and safety and are under discussions. A wide variety in their use is reported in the literature and clear evidence about which inotrope or other treatment should be preferred is lacking. In addition, there is ongoing debate about the appropriate threshold values for blood pressure. Other diagnostic measures for poor circulation are functional echocardiography, near-infrared spectroscopy, capillary refill time, base excess and serum lactate. Large randomised controlled trials for the use of dopamine and dobutamine in preterm infants <32 weeks gestation are under way to fill the knowledge gaps on the assessment of circulatory compromise and on efficacy and safety of the studied age-appropriate drug formulations.

Is Serum Bicarbonate Level Associated With Negative Outcomes in Pediatric Patients?: A Retrospective Cohort Study

OBJECTIVES

Early identification of children at risk for adverse outcomes is important. Serum bicarbonate is easily collected and widely available. We described the relationship between bicarbonate and adverse outcomes in children presenting to the emergency department (ED).

METHODS

We conducted a retrospective cohort study of children aged 0 to 17 years from January 1, 2007, to December 31, 2011, who had a serum bicarbonate measured in the ED. Primary outcome was the predictive ability of bicarbonate for the individual components of the composite outcome that included at least one of the following: intensive care unit admission, assisted ventilation, inotropic support, cardiopulmonary resuscitation, or death. Secondary outcome was the relationship between bicarbonate level of greater and less than 13 mEq/L and the composite outcome.

RESULTS

We reviewed 16,989 charts, of which 432 had an adverse outcome. Receiver operating characteristic curve analysis showed that a bicarbonate level of less than 18.5 mEq/L predicted inotropic support with an area under the curve of 0.69 (95% confidence interval [CI], 0.60-0.77; P < 0.001) and death with an area under the curve of 0.75 (CI, 0.66-0.85; P < 0.001). Significantly more patients with bicarbonate level of less than 13 mEq/L had at least 1 adverse outcome compared with those with bicarbonate level of greater than 13 mEq/L (4.4% vs 2.5%, P = 0.001), odds ratio 1.96 (95% CI, 1.3-2.97).

CONCLUSIONS

Among children presenting to the ED, bicarbonate level of 18.5 mEq/L had fair specificity in predicting inotropic support and death. Negative outcomes are significantly associated with bicarbonate level of less than 13 mEq/L. Bicarbonate should routinely be measured in children at risk of clinical deterioration.

Uses and misuses of sodium bicarbonate in the neonatal intensive care unit

Over the past several decades, bicarbonate therapy continues to be used routinely in the treatment of acute metabolic acidosis in critically ill neonates despite the lack of evidence for its effectiveness in the treatment of acid-base imbalance, and evidence indicating that it may be detrimental. Clinicians often feel compelled to use bicarbonate since acidosis implies a need for such therapy and thus the justification for its use is based on hearsay rather than science. This review summarizes the evidence and refutes the clinical practice of administering sodium bicarbonate to treat metabolic acidosis associated with several specific clinical syndromes in neonates.

How to assess hemodynamic status in very preterm newborns in the first week of life?

BACKGROUND

Assessing hemodynamic status in preterm newborns is an essential task, as many studies have shown increased morbidity when hemodynamic parameters are abnormal. Although oscillometric monitoring of arterial blood pressure (BP) is widely used due to its simplicity and lack of side effects, these values are not always correlated with microcirculation and oxygen delivery.

OBJECTIVES

This review focuses on different tools for the assessment of hemodynamic status in preterm newborns. These include the measurement of clinical (BP, capillary refill time and urinary output (UO)) or biological parameters (lactate analysis), functional echocardiography, and near-infrared spectroscopy (NIRS). We describe the concepts and techniques involved in these tools in detail, and examine the interest and limitations of each type of assessment.

CONCLUSIONS

This review highlights the complementarities between the different parameters used to assess hemodynamic status in preterm newborns during the first week of life. The analysis of arterial BP measured by oscillometric monitoring must take into account other clinical data, in particular capillary refill time and UO, and biological data such as lactate levels. Echocardiography improves noninvasive hemodynamic management in newborns but requires specific training. In contrast, NIRS may be useful in monitoring the clinical course of infants at risk of, or presenting with, hypotension. It holds the potential for early and noninvasive identification of silent hypoperfusion in critically ill preterm infants. However, more data are needed to confirm the usefulness of this promising tool in significantly changing the outcome of these infants.

Persistent Hyperlactatemia as the Predictor of Poor Outcome in Critically Ill Children: A Single-Center, Prospective, Observational Cohort Study

Objective  To study incidence of hyperlactatemia and its correlation with outcome in critically ill children. Design  Single-center, prospective cohort study. Setting  Eight-bedded PICU. Method  Serial serum lactate levels were measured in 140 critically ill children at 0, 12, 24, and 48 hours. Results  A total of 45% children had hyperlactatemia. Lactate levels were significantly ( p  = 0.000) higher in nonsurvivors at all intervals. Lactate levels decreased significantly ( p  = 0.000) in survivors while increased in nonsurvivors. Normalized lactate load was found to be an independent predictor of mortality ( p  = 0.023). Conclusion  Persistent hyperlactatemia serves as a possible predictor of poor outcome in critically ill children.

Reference values for nucleated red blood cells and serum lactate in very and extremely low birth weight infants in the first week of life

STUDY PURPOSE

To provide reference values for nucleated red blood cells and serum lactate concentrations in very and extremely low birth weight (VLBW/ELBW) infants in the first week of life.

PATIENTS AND METHODS

Retrospective data analysis of serial, daily measurements of NRBC counts and serum lactate during the first 6days of life in VLBW and ELBW infants.

RESULTS

In total, 250 infants<1500g were included in this study. Intrauterine growth retardation (IUGR) was seen in 87 (34.8%) patients. Gestational age (GA) ranged from 23 to 35weeks (mean 29.0weeks) and birth weight (BW) was 320-1499g (mean 1047.9g). During hospital stay, 55 (22%) patients developed IVH and 55 children (22%) BPD. PVL was seen in 12 (4.8%) cases, ROP in 93 (37.2%) and NEC in only 1 (0.4%) patient. NRBC counts as well as serum lactate concentrations depended significantly on birth weight (p<0.01) and presence respectively absence of IUGR (p<0.01). Both NRBC counts and serum lactate concentrations declined constantly during the 6-day period (p<0.01), and both were highly inter-correlated (p<0.01).

CONCLUSIONS

This is one of only a very few studies that systematically and serially evaluated both NRBC counts and serum lactate concentration in VLBW and ELBW infants in the first 6days of life. Both parameters were significantly dependent on birth weight and the presence of IUGR. Moreover, a significant correlation between NRBC counts and serum lactate concentrations in this early period of life could be demonstrated. In future studies, the role of these readily available biomarkers in predicting important neonatal outcome parameters needs to be evaluated in a prospective manner.

Serum Lactate, Brain Magnetic Resonance Imaging and Outcome of Neonatal Hypoxic Ischemic Encephalopathy after Therapeutic Hypothermia

BACKGROUND

Serum lactate was used to predict the severity and outcome of neonatal hypoxic ischemic encephalopathy (HIE) before the era of therapeutic hypothermia (TH). There is no report on neurodevelopment (ND) outcome of neonates with HIE treated with TH in Taiwan.

METHODS

Between April 2011 and December 2012, newborn infants admitted to Chang Gung Memorial Hospital (CGMH), with gestational age > 35 weeks and birth weight ≥ 1800 g, who had acute perinatal events, evidence of significant fetal compromise, and ongoing clinical encephalopathy were prospectively enrolled for TH. Whole body cooling method was used to maintain the affected neonate's esophageal temperature at 33.5 ± 0.5 °C for 72 hours. Demographic data were recorded and hemogram, biochemical parameters, serum lactate, and creatine kinase (CK) were measured as well. Brain magnetic resonance imaging (MRI) was performed between 7 and 14 days of life. ND outcome of infants was evaluated by Bayley Scales of Infant Development, third edition (BSID-III) at 24 months of corrected age. Poor ND (PND) outcome was defined as infants surviving with either disability or ND delay.

RESULTS

Seventeen patients were enrolled. Fifty-nine percent of babies (10/17) were born through cesarean section and 77% of babies (13/17) were transferred from outside hospitals. Six babies were moderate HIE and 11 babies were severe HIE. Among the 14 surviving patients, eight infants had PND outcome. There was no difference in demographic data between infants with and without PND. Serum level of lactate (mg/dL) after 72 hours of TH was higher (35.6 vs. 13.8, p = 0.042) in infants with PND. Neonates with abnormal brain MRI findings were also associated with PND (p = 0.01).

CONCLUSION

This is the first report on ND outcome of neonates with HIE treated with TH in Taiwan. Higher serum level of lactate following TH and abnormal results of brain MRI are associated with poor ND outcome.

Neonatal echocardiography

Echocardiography is a technique within neonatal care increasingly used in acute management of patients because of its potential to guide care and hemodynamic management. However, its use continues to provoke controversy, as it was originally within the purview of pediatric cardiologists trained to identify structural as well as functional heart disease. This article examines some of the echocardiographic techniques available to the neonatologist, their applications, and the concerns surrounding their use on neonatal units.

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.

Early-onset thrombocytopenia in near-term and term infants with perinatal asphyxia

BACKGROUND

Neonates after perinatal asphyxia are at increased risk of thrombocytopenia. The correlation between perinatal asphyxia and the risk and severity of early-onset thrombocytopenia is not well known.

OBJECTIVE

To estimate the incidence, severity and risk factors for early-onset thrombocytopenia in neonates after perinatal asphyxia.

METHODS

We included all newborns (gestational age ≥ 36 weeks) admitted to our neonatal nursery due to perinatal asphyxia in this retrospective study. We collected platelet counts that were obtained within the first 48 h of life to estimate the incidence and severity of early-onset thrombocytopenia.

RESULTS

A total number of 171 neonates with perinatal asphyxia were included in the study. The incidence of early-onset thrombocytopenia (platelet count < 150 × 109/l) was 51% (87/171). Several factors were associated with increased risk of early-onset thrombocytopenia, including prolonged prothrombin time (PT) [odds ratio (OR) 1·18, 95% confidence interval (CI) 1·08–1·30, P < 0·01], prolonged activated partial thromboplastin time (APTT) (OR 1·07, 95% CI 1·03–1·11, P < 0·01), low Apgar score at 10 min (OR 1·25, 95% CI 1·08–1·45, P < 0·01) and high serum lactate (OR 1·12, 95% CI 1·06–1·19, P < 0·01). After multiple logistic regression analysis, we found an independent association between early-onset thrombocytopenia and prolonged PT (OR 1·15, 95% CI 1·00–1·33, P = 0·045) and higher lactate level (OR 1·15, 95% CI 1·03–1·28, P = 0·01).

CONCLUSIONS

Early-onset thrombocytopenia occurs frequently in neonates after perinatal asphyxia and is independently associated with PT and lactate level.

Management of hypotension in preterm infants (The HIP Trial): a randomised controlled trial of hypotension management in extremely low gestational age newborns

BACKGROUND

Extremely preterm babies (delivered at <28 completed weeks of gestation) are frequently diagnosed with hypotension and treated with inotropic and pressor drugs in the immediate postnatal period. Dopamine is the most commonly used first-line drug. Babies who are treated for hypotension more frequently sustain brain injury, have long-term disability or die compared to those who are not. Despite the widespread use of drugs to treat hypotension in such infants, evidence for efficacy is lacking, and the effect of these agents on long-term outcomes is unknown.

HYPOTHESIS

In extremely preterm babies, restricting the use of dopamine when mean blood pressure (BP) values fall below a nominal threshold and using clinical criteria to determine escalation of support ('restricted' approach) will result in improved neonatal and longer-term developmental outcomes. RESEARCH PLAN: In an international multi-centre randomised trial, 830 infants born at <28 weeks of gestation, and within 72 h of birth, will be allocated to 1 of 2 alternative treatment options (dopamine vs. restricted approach) to determine the better strategy for the management of BP, using a conventional threshold to commence treatment. The first co-primary outcome of survival without brain injury will be determined at 36 weeks' postmenstrual age and the second co-primary outcome (survival without neurodevelopmental disability) will be assessed at 2 years of age, corrected for prematurity.

DISCUSSION

It is essential that appropriately designed trials be performed to define the most appropriate management strategies for managing low BP in extremely preterm babies.

The relationship between blood lactate concentration, the Paediatric Index of Mortality 2 (PIM2) and mortality in paediatric intensive care

INTRODUCTION

Blood lactate concentration predicts mortality in neonates, infants, children and adults, with evidence that it has better predictive power than other markers of acid-base status such as absolute base excess or pH.

OBJECTIVE

To investigate whether blood lactate concentration on admission predicts mortality in paediatric intensive care and if its addition can improve the performance of the Paediatric Index of Mortality 2 (PIM2) mortality prediction score.

DESIGN AND SETTING

Retrospective cohort study in one 20-bed UK paediatric intensive care unit (PICU) using data from the PICU clinical and blood gas analyser databases between 2006 and 2010. Only cases with a blood lactate concentration measured at the same time as the PIM2 variables were included. Logistic regression was used to assess if blood lactate concentration predicted mortality independently of PIM2, adjusting for potential confounders, and if it could replace absolute base excess in the PIM2 model.

RESULTS

There were 155 deaths amongst 2,380 admissions (6.5 %). Admission lactate in non-survivors was higher than in survivors (mean [standard deviation, SD]) 6.6 [5.6] versus 3.0 [2.5] mmol/l, had a positive association with mortality [adjusted odds ratio (OR) for death per unit (mmol/l)] increase 1.11 [95 % confidence interval (CI) 1.06-1.16; p < 0.001] and significantly improved the model fit of PIM2 when it replaced absolute base excess (p < 0.001).

CONCLUSIONS

PICU admission blood lactate concentration predicts mortality independently of PIM2. Given the limitations of this study, a prospective multi-centre evaluation is required to establish whether it should be added to the PIM2 model with or without replacement of base excess.

Peritoneal drainage versus laparotomy for perforated necrotising enterocolitis or spontaneous intestinal perforation: a retrospective cohort study

AIM

Perforated necrotising enterocolitis (NEC) and spontaneous intestinal perforation (SIP) in preterm infants are associated with high morbidity and mortality. The optimum surgical management during the acute stage remains unclear. The aim of the study was to compare the outcomes of preterm infants (gestational age at birth <30 weeks) with perforated NEC or SIP undergoing primary peritoneal drainage (PD) versus laparotomy.

METHODS

This was a retrospective cohort study (January 2004 to February 2010). Initial search of hospital database followed by a review of the medical records was performed to identify eligible infants. Thirty-nine infants were included in the study. Information regarding the baseline characteristics and outcomes of interest were recorded using the medical charts, radiology and laboratory databases. NEC was differentiated from SIP based on radiological, operative and clinical findings retrospectively for this study.

RESULTS

Among 39 infants, 19 underwent primary PD while 20 had primary laparotomy. Gestational age and birthweight were similar between the two groups. The composite outcome of mortality before discharge or hospital stay longer than 3 months post-term was significantly worse in PD group (74% vs. 40%, P= 0.038).

CONCLUSIONS

Preterm infants undergoing PD for NEC/SIP appeared to have increased risk of adverse outcome compared with laparotomy. More randomised controlled trials are necessary to confirm these findings.

Serum lactate levels as the predictor of outcome in pediatric septic shock

Background and Aims:

An association of high lactate levels with mortality has been found in adult patients with septic shock. However, there is controversial literature regarding the same in children. The aim of this study was to find the correlation of serum lactate levels in pediatric septic shock with survival.

Settings and Design:

This was a prospective observational study at PICU of a tertiary care center of North India.

Materials and Methods:

A total of 30 children admitted to PICU with diagnosis of septic shock were included in the study. PRISM III score and demographic characteristics of all children were recorded. Serum lactate levels were measured in arterial blood at 0-3, 12, and 24 h of PICU admission. The outcome (survival or death) was correlated with serum lactate levels.

Results:

Septic shock was the most common (79.3%) type of shock and had 50% mortality. Initial as well as subsequent lactate levels were significantly higher in nonsurvivors. A lactate value of more than 45 mg/dl (5 mmol/l) at 0–3, 12, and 24 h of PICU admission had an odds ratio for death of 6.7, 12.5, and 8.6 (95% CI: 1.044–42.431, 1.850–84.442, 1.241–61.683) with a positive predictive value (PPV) of 38%, 71%, 64% and a negative predictive value (NPV) of 80%, 83%, and 83%, respectively.

Conclusions:

Nonsurvivors had higher blood lactate levels at admission as well as at 12 and 24 h. A lactate value of more than 45 mg/dl (5 mmol/l) was a good predictor of death.

Acid-base disorders in critically ill neonates

Objective:

To study acid–base imbalance in common pediatric diseases (such as sepsis, bronchopneumonia, diarrhea, birth-asphyxia etc.) in neonates.

Design and Setting:

An observational study was conducted in an emergency room of a tertiary teaching care hospital in Haryana, India.

Patients and Methods:

Fifty neonates (from first hour to one month) attending pediatric emergency services with various ailments. Blood gas analysis, electrolytes, plasma lactate, and plasma albumin were estimated in neonates.

Results:

Metabolic acidosis was the most common acid–base disorder. Hyperlactatemia was observed in more than half of such cases. Birth asphyxia was another common disorder with the highest mortality in neonates followed by bronchopneumonia and sepsis. Significant correlation between mortality and critical values of lactate was observed.

Conclusion:

Birth asphyxia with high-lactate levels in neonates constituted major alterations in acid–base disorders seen in an emergency room of a tertiary teaching care hospital. Plasma lactate concentration measurement provides an invaluable tool to assess type of metabolic acidosis in addition to predicting mortality in these neonates.

Lactate and acid base as a hemodynamic monitor and markers of cellular perfusion

BACKGROUND

: The intra- and postoperative monitoring of lactate and acid-base has been advocated in pediatric cardiac critical care as surrogate markers of cardiac output, oxygen delivery, and cellular perfusion. Many clinicians use lactate and base excess routinely as markers of tissue perfusion and to assess the effectiveness of their intervention. This review discusses the strengths and weaknesses of using these measurements in pediatric cardiac critical care.

METHODOLOGY

: A search of MEDLINE, EMBASE, PubMed, and the Cochrane Database was conducted to find controlled trials of lactate and base excess. Adult and pediatric data were considered. Guidelines published by the Society of Critical Care Medicine, the American Heart Association, the American Academy of Pediatrics, and the International Liaison Committee on Resuscitation were reviewed including further review of references cited.

RESULTS AND CONCLUSIONS

: Many factors other than tissue hypoxia may contribute to hyperlactemia in critical illness. Although the presence of hyperlactemia on admission appears to be associated with intensive care unit mortality and morbidity in some retrospective analyses, significant overlap between survivors and nonsurvivors means that nonsurvivors cannot be predicted from admission lactate measurement. Persistently elevated postoperative lactate is associated with increased morbidity and mortality in the pediatric cardiac population. To date there is no randomized control trial of goal-directed therapy in adult or pediatric cardiac care that includes normalization of lactate as a target. Overall equivalent time measurements of base excess, anion gap, and pH have a low predictive value for morbidity and mortality in children after cardiac surgery. Lactate is one of a cluster of markers of cellular perfusion and oxygen delivery. Alone, as a single measurement, it has minimal predictive value and is nondiscriminatory for survival.