Diagnostic criteria and therapeutic interventions for the hypotensive very low birth weight infant

Vasopressin as adjunctive therapy in pulmonary hypertension associated with refractory systemic hypotension in term newborns

OBJECTIVE

The use of vasopressin as an adjunctive therapy in pulmonary hypertension associated with refractory systemic hypotension has increased. The objective of our study is to describe its effects on term infants.

STUDY DESIGN

Retrospective observational study. Setting in a referral level IV neonatal intensive care unit from a middle-income region. The patients are term neonates admitted to our NICU who required vasopressin due to severe Pulmonary Hypertension and refractory hypotension during a 49-month period (December 2019 and December 2023).

RESULTS

We identified 68 term infants, all in mechanical ventilation, receiving inhaled nitric oxide (iNO), and a phased protocol management for hypotension. Vasopressin was a started at a mean of 2 days with a mean duration of 80 h. Regarding hemodynamic outcome: diastolic, systolic, and median systemic pressure significantly increased during the first 4 h of treatment, as well as arterial pH and urine output. Accordingly, lactate and Vasoactive Inotropic Score (VIS) score decreased after 4 and 8 h, respectively, after vasopressin was started. Regarding oxygenation markers: oxygen requirements and mean airway pressure decreased significantly (and therefore the oxygenation index decreased in concordance) after 4 h of vasopressin. Echocardiographic indices of pulmonary hypertension progressively improved after vasopressin infusion with a significant decrease of tricuspid ingurgitation velocities and the rate of right-to- left ductal shunt through the ductus arteriosus. In the same way, left and right ventricular output increased after the initiation of vasopressin.

CONCLUSION

This study showed that the use of vasopressin in neonates with persistent pulmonary hypertension was associated with a rapid and significant improvement in oxygenation and hemodynamic markers of perfusion, including blood pressure. Its effects begin early during the first hours of treatment.

The prediction of estimated cerebral perfusion pressure with trans-systolic time in preterm and term infants

It is important to monitor cerebral perfusion in infants because hypo- and hyperperfusion can contribute to neurological injury. This study aimed to clarify the relationship between trans-systolic time (TST) and critical closing pressure (CrCP) or estimated cerebral perfusion pressure (CPPe) in neonates. Moreover, we aimed to determine the TST values in preterm and term infants with stable cerebral perfusion to clarify normative reference data. This multicentre prospective study included infants with arterial lines admitted to the neonatal intensive care units between December 2021 and August 2023. TST, CrCP, and CPPe were calculated using middle cerebral artery waveforms recorded using transcranial Doppler ultrasonography when clinicians collected arterial blood samples. Three hundred and sixty samples were obtained from 112 infants with a gestational age of 32 (interquartile range, 27-37) weeks and a birth weight of 1481 (956-2355) g. TST was positively correlated with CPPe (r = 0.60, p < 0.001), but not with CrCP (r = 0.08, p = 0.10). The normative reference values of TST in preterm and term infants without samples of hyper- or hypocapnia and/or hyper- or hypotension, which may affect cerebral perfusion, were as follows: ≤ 29 weeks, 0.12 (0.11-0.14) s; 30-36 weeks, 0.14 (0.12-0.15) s; and ≥ 37 weeks, 0.16 (0.14-0.17) s, respectively.  Conclusion: TST in neonates significantly correlated with CPPe, but not with CrCP. TST may be a good predictor of cerebral perfusion and potentially have wider clinical applications. What is Known: • Trans-systolic time (TST) is used in evaluating the effects of increased intracranial pressure on cerebral haemodynamics. However, little is known about the efficacy of TST in predicting neonatal cerebral perfusion pressure. What is New: • This study added evidence that TST correlated with estimated cerebral perfusion pressure, but not with critical closing pressure. Additionally, we showed the normative reference values of the TST in preterm and term infants.

Guidelines and Recommendations for Targeted Neonatal Echocardiography and Cardiac Point-of-Care Ultrasound in the Neonatal Intensive Care Unit: An Update from the American Society of Echocardiography

Targeted neonatal echocardiography (TNE) involves the use of comprehensive echocardiography to appraise cardiovascular physiology and neonatal hemodynamics to enhance diagnostic and therapeutic precision in the neonatal intensive care unit. Since the last publication of guidelines for TNE in 2011, the field has matured through the development of formalized neonatal hemodynamics fellowships, clinical programs, and the expansion of scientific knowledge to further enhance clinical care. The most common indications for TNE include adjudication of hemodynamic significance of a patent ductus arteriosus, evaluation of acute and chronic pulmonary hypertension, evaluation of right and left ventricular systolic and/or diastolic function, and screening for pericardial effusions and/or malpositioned central catheters. Neonatal cardiac point-of-care ultrasound (cPOCUS) is a limited cardiovascular evaluation which may include line tip evaluation, identification of pericardial effusion and differentiation of hypovolemia from severe impairment in myocardial contractility in the hemodynamically unstable neonate. This document is the product of an American Society of Echocardiography task force composed of representatives from neonatology-hemodynamics, pediatric cardiology, pediatric cardiac sonography, and neonatology-cPOCUS. This document provides (1) guidance on the purpose and rationale for both TNE and cPOCUS, (2) an overview of the components of a standard TNE and cPOCUS evaluation, (3) disease and/or clinical scenario-based indications for TNE, (4) training and competency-based evaluative requirements for both TNE and cPOCUS, and (5) components of quality assurance. The writing group would like to acknowledge the contributions of Dr. Regan Giesinger who sadly passed during the final revisions phase of these guidelines. Her contributions to the field of neonatal hemodynamics were immense.

The association of cumulative vasoactive drugs and neurodevelopmental outcomes in preterm Infants <29 weeks gestation

OBJECTIVE

To assess the effect of cardiovascular medications on the neurodevelopment of preterm infants, as measured by calculated cumulative time of vasoactive-inotropic score (VISct).

METHODS

A retrospective study was conducted on preterm infants who developed significant hypotension defined as a mean BP more than 2SDs below the mean for GA and received treatment with duration > 6 hours for each hypotensive episode, we calculated the vasoactive inotropic score (VIS) and cumulative exposure to cardiovascular medications over time (VISct). The composite Bayley III was reported from the high-risk follow-up clinic for the surviving infants between 18 to 21 months corrected age.

RESULTS

VISct was significantly higher in infants with abnormal neurodevelopment. Cognitive Bayley was the most affected component with median (IQR) VISct 882.5(249,2047) versus 309(143,471) (p-value 0.012), followed by language function with VISct 786(261,1563.5), versus 343(106.75,473.75) (p-value 0.016) when those with Bayley III <85 were compared with those with normal Bayley IIIs.

CONCLUSION

High VISct scores may have negative effect on cognitive and language neurodevelopmental outcomes.

Hemodynamic evaluation of extremely low birth weight infants during the first 7 days of life

BACKGROUND AND AIM

We aimed to investigate the hemodynamic status of extremely low birth weight (ELBW) infants during the transitional period under intensive management.

METHODS

This retrospective cohort study analyzed left ventricular ejection fraction (LVEF), left ventricular end-systolic wall stress (ESWS), left ventricular internal dimension in diastole (LVIDd), and mean arterial pressure (MAP) of ELBW infants during their first week of life. Small for gestational age (SGA), histological chorioamnionitis (hCAM), severe intraventricular hemorrhage (IVH), and non-survival to discharge infants were compared to their counterparts.

RESULTS

Sixty-two infants (25.7 ± 2.1 weeks, 700.7 ± 165.4 g) were analyzed. MAP gradually increased. Median LVEF was 69.8 % on day 1, decreased to 62.7 % on day 2, then increased throughout the week. ESWS was lowest at birth, rose to 28.2 g/cm2 on day 2, and decreased on day 6. There were no significant changes in LVIDd. SGA infants had higher MAP throughout, higher LVEF on day 2 and 3, but lower LVEF on day 5 to 7. LVIDd was lower in hCAM group. Severe IVH group had a more significant drop in LVEF on day 2, higher ESWS, and a higher incidence of hemodynamic significant patent ductus arteriosus (hsPDA). Non-survival had lower LVIDd.

CONCLUSIONS

MAP increased gradually. Hemodynamic instability was observed in the first two days, with decreased LVEF and increased ESWS before stabilization. We observed an alteration in hemodynamic adaptation in SGA and hCAM infants. Severe IVH group experienced early hemodynamic instability and a higher incidence of hsPDA.

Changes in respiratory mechanics in response to crystalloid infusions in extremely premature infants

Extremely premature infants are at a higher risk of developing respiratory distress syndrome and circulatory impairments in the first few weeks of life. Administration of normal saline boluses to manage hypotension is a common practice in preterm infants. As a crystalloid, a substantial proportion might leak into the interstitium; most consequently the lungs in the preterm cohorts, putatively affecting ventilation. We downloaded and analyzed ventilator mechanics data in infants managed by conventional mechanical ventilation and administered normal saline bolus for clinical reasons. Data were downloaded for 30 min prebolus, 60 min during the bolus followed by 30 min postbolus. Sixteen infants (mean gestational age 25.2 ± 1 wk and birth weight 620 ± 60 g) were administered 10 mL/kg normal saline over 60 min. The most common clinical indication for saline was hypotension. No significant increase was noted in mean blood pressure after the saline bolus. A significant reduction in pulmonary compliance (mL/cmH2O/kg) was noted (0.43 ± 0.07 vs. 0.38 ± 0.07 vs. 0.33 ± 0.07, P = 0.003, ANOVA). This was accompanied by an elevation in the required peak inspiratory pressure to deliver set volume-guarantee (19 ± 2 vs. 22 ± 2 vs. 22 ± 3 mmHg, P < 0.0001, ANOVA), resulting in a higher respiratory severity score. Normal saline infusion therapy was associated with adverse pulmonary mechanics. Relevant pathophysiologic mechanisms might include translocation of fluid across pulmonary capillaries affected by low vascular tone and heightened permeability in extremes of prematurity, back-pressure effects from raised left atrial volume due to immature left-ventricular myocardium; complemented by the effect of cytokine release from positive pressure ventilation.NEW & NOTEWORTHY Administration of saline boluses is common in premature infants although hypovolemia is an uncommon underlying cause of hypotension. This crystalloid can redistribute into pulmonary interstitial space. In the presence of an immature myocardium and diastolic dysfunction, excess fluid can also be "edemagenic." This study on extremely premature infants (25 wk gestation) noted adverse influence on respiratory physiology after saline infusion. Clinicians need to choose judiciously and reconsider routine use of saline boluses in premature infants.

Comparison of clinical outcomes between active and permissive blood pressure management in extremely preterm infants

Background

There remains uncertainty about the definition of normal blood pressure (BP), and when to initiate treatment for hypotension for extremely preterm infants. To determine the short-term outcomes of extremely preterm infants managed by active compared with permissive BP support regimens during the first 72 hours of life.

Method

This is a retrospective medical records review of 23 +0-28 +6 weeks' gestational age (GA) infants admitted to neonatal units (NNU) with active BP support (aimed to maintain mean arterial BP (MABP) >30 mmHg irrespective of the GA) and permissive BP support (used medication only when babies developed signs of hypotension) regimens. Babies admitted after 12 hours of age, or whose BP data were not available were excluded.

Results

There were 764 infants admitted to the participating hospitals; 671 (88%) were included in the analysis (263 active BP support and 408 permissive BP support). The mean gestational age, birth weight, admission temperature, clinical risk index for babies (CRIB) score and first haemoglobin of infants were comparable between the groups. Active BP support group infants had consistently higher MABP and systolic BP throughout the first 72 hours of life (p<0.01). In the active group compared to the permissive group 56 (21.3%) vs 104 (25.5%) babies died, and 21 (8%) vs 51 (12.5%) developed >grade 2 intra ventricular haemorrhage (IVH). Death before discharge (adjusted OR 1.38 (0.88 - 2.16)) or IVH (1.38 (0.96 - 1.98)) was similar between the two groups. Necrotising enterocolitis (NEC) ≥stage 2 was significantly higher in permissive BP support group infants (1.65 (1.07 - 2.50)).

Conclusions

There was no difference in mortality or IVH between the two BP management approaches. Active BP support may reduce NEC. This should be investigated prospectively in large multicentre randomised studies.

Use of Vasopressors in Extremely Preterm Infants in First Week of Life

OBJECTIVE

 A significant variability exists for diagnosis and treatment of hypotension in extremely preterm infants. Benefits of the use of vasopressors remain unclear. We wanted to identify the risk factors associated with use of vasopressors in the first week of life and their impact on outcomes of extremely preterm infants.

STUDY DESIGN

 Retrospective review of all newborns ≤28 weeks of gestational age (GA) admitted in neonatal intensive care unit from October 1, 2012, to October 31, 2015, done. Data regarding antenatal and neonatal characteristics and outcomes were recorded. Study infants were divided into two cohorts and compared based on vasopressor use. Chi-square, t-test, and multiple logistic regression were performed as appropriate and significance set at p <0.05.

RESULTS

 Of 213 extremely preterm infants, 90 (42.3%) received vasopressors in first week of life. The mean arterial pressure (MAP) at admission in these infants was significantly lower than that of infants who did not require vasopressors (27 ± 8 vs. 30 ± 6 mm Hg, p < 0.05). Vasopressors were initiated within 24 hours in 91% of babies. After controlling for other variables, use of vasopressors was significantly higher in infants with lower birth weight (odds ratio [OR]: 3.2, 95% confidence interval [CI]: 1.6-8.3), 5-minute Apgar's score ≤5 (OR: 1.8, 95% CI: 1.2-3.12), and admission hypothermia (OR: 2.7, 95% CI: 1.3-4.9). The use of vasopressors was significantly associated with severe intraventricular hemorrhage (IVH), even after controlling for other significant variables (OR: 5.9, 95% CI: 1.6-9.3).

CONCLUSION

 Lower birth weight, low 5-minute Apgar's score, and admission hypothermia are characteristics associated with early use of vasopressors in extremely preterm infants. Infants treated with vasopressors are at a higher risk of developing severe IVH.

KEY POINTS

· Low systemic blood pressure is a very common problem in the extremely preterm population.. · In clinical practice, mean arterial blood pressure (BP) less than the infants GA in week is typically considered to be "low BP.". · About 50% of infants born at <29 weeks of GA received very preterm in the first week of life.. · Use of vasopressors is associated with a higher incidence of intraventricular hemorrhage in extremely preterm population..

Evaluation of the Hypotensive Preterm Infant: Evidence-Based Practice at the Bedside?

Choosing the appropriate management approach for the preterm infant with low blood pressure during the transition period generally involved intervening when the blood pressure drifted below a certain threshold. It is now clear that this approach is too simplistic and does not address the underlying physiology. In this chapter, we explore the many monitoring tools available for evaluation of the hypotensive preterm and assess the evidence base supporting or refuting their use. The key challenge relates to incorporating these outputs with the clinical status of the patient and choosing the appropriate management strategy.

Brain-Oriented Strategies for Neuroprotection of Asphyxiated Newborns in the First Hours of Life

Perinatal asphyxia represents the first cause of severe neurological disabilities and the second cause of neonatal death in term-born babies. Currently, no treatment can prevent immediate cell death from necrosis, but some therapeutic interventions, such as therapeutic hypothermia (TH), can reduce delayed cell death from apoptosis. TH significantly improves the combined outcome of mortality or major neurodevelopmental disability, but the number of patients to be treated is 7 to get 1 child with no adverse neurological outcome. The aim of this educational review is to analyze the other care strategies to be implemented to improve the neurological outcome of children with hypoxic ischemic encephalopathy (HIE). Hypocapnia, hypoglycemia, pain control, and functional brain monitoring are recognized as appropriate approaches to improve outcome in critically ill infants with HIE. Pharmacologic neuroprotective adjuncts are currently under investigation. New drugs such as allopurinol and melatonin seem to provide positive effects although more randomized controlled trials are required to establish the effective therapeutic scheme. In the meantime, sustaining the respiratory, metabolic, and cardiovascular system during TH can be a valuable aid in managing and treating the patient with HIE in an optimal way.

Normal values for superior vena cava flow in preterm neonates using a new echocardiographic approach

OBJECTIVE

Recently, a novel approach to imaging Superior Vena Cava (SVC) flow has been presented, showing better repeatability and better agreement with MRI-derived SVC flow measures. The objective was to establish normal values of SVC flow with the novel approach in the first 48 h of life.

STUDY DESIGN

This was a prospective, observational study. All infants with gestational age (GA) less than 31 weeks were eligible. Echocardiographic evaluation was performed at 5, 12, 24, 48 h of postnatal life. A subgroup of uncomplicated infants was studied to define a normal range for SVC flow.

RESULTS

Forty-five infants were enrolled. We estimated normative values in a subgroup of 31 uncomplicated infants. The median SVC flow significantly increases from 83 ml/kg/min at 5 h of life to 153 ml/kg/min at 48 h (p < .001).

CONCLUSION

Using the novel approach we derived normal values of SVC flow in a cohort of uncomplicated preterm population at high risk for developing IVH.

A vasoactive inotropic score predicts the severity of compromised systemic circulation and mortality in preterm infants

OBJECTIVE

To validate the vasoactive inotropic score as a predictor of the severity of compromised systemic circulation and mortality in preterm infants.

METHODS

A retrospective study was conducted on preterm infants with Compromised systemic circulation [hypotension±lactic acidosis±oliguria] who received a cardiovascular support, we calculated the vasoactive inotropic score (VIS) and cumulative exposure to cardiovascular medications over time (VISct). Receiver operator curve was constructed to predict the primary outcome which was death & refractory hypotension.

RESULTS

VIS had an area under the curve of 0.73 (95% CI 0.85-0.98, p <  0.001). A VIS cut off of 25 has sensitivity and specificity of 66% and 92%, and positive and negative predictive values of 78.5% and 83%, respectively.

CONCLUSION

High VIS predicts the severity of Compromised systemic circulation and mortality rate in preterm infants.

Which Inotropic Drug, Dobutamine or Milrinone, Is Clinically More Effective in the Treatment of Postligation Cardiac Syndrome in Preterm Infants?

OBJECTIVE

This study aimed to detect which of the two main medicines suggested in the treatment of postligation cardiac syndrome (PLCS)-dobutamine or mirinone-possesses a more therapeutic effect. While doing this, clinicians are provided with a broader perspective on the treatment and follow-up of cases. The desire was to increase the treatability and monitor ability of the cases in question and hence their survivability.

STUDY DESIGN

A retrospective review of a cohort of infants with PLCS was conducted between March 2012 and December 2018. In the treatment of infants with PLCS, dobutamine (dobutamine study group-DSG) or milrinone (milrinone study group-MSG) was used. The respiration, cardiac, echocardiography, and perfusion parameters of the cases were assessed both before and after ligation. Based on the data obtained, both the effects of the medicines on PLCS and the difference between their therapeutic effects were studied. The accuracy of prognostication was assessed with receiver operating characteristic analyses.

RESULTS

PLCS was detected in 29 (34.1%) of 85 patent ductus arteriosus ligation cases in total. Of all the PLCS cases, 13 (44.8%) were treated with dobutamine and 16 (55.2%) with milrinone. It was observed that the effects of the medicines on the respiratory system and cardiovascular system manifested in the third and 6th hour, respectively. It was detected that both medicines had more effect on the systolic blood pressure (SBP) (area under the curve [AUC]: 0.997/0.996, p = 0.001/0.002) than on the diastolic blood pressure (AUC: 0.911/0.843, p = 0.032/0.046).

CONCLUSION

Dobutamine and milrinone, two primary medicines that can be used in the treatment of cases with PLCS, possess similar therapeutic effects on this pathology. In addition, their postoperative therapeutic effects on the SBP are more in the foreground.

Risk factors and prognosis in very low birth weight infants treated for hypotension during the first postnatal week from the Korean Neonatal Network

Hypotension in the early stages of life appears in 20% of very low birth weight (VLBW) infants. The gestational age and birth weight are the risk factors highly related to the postnatal hypotension. Other risk factors slightly differ between different studies. So, we evaluated the risk factors and prognosis that are associated with infants treated with hypotension in the early stages of life, after excluding the influences of gestational age and small for gestational age (SGA). VLBW infants registered in the Korean Neonatal Network between 2013 and 2015 treated for hypotension within a week after their birth were selected as study subjects. The rest were used as a control group. Risk factors and the prevalence of severe complications, including mortality, were investigated and compared after matching for gestational age and SGA. The treatment rate for hypotension within the first postnatal week was inversely related to decreasing gestational ages and birth weights. In particular, 63.4% of preterm infants born at ≤ 24 weeks’ gestation and 66.9% of those with a birth weight < 500 g were treated for hypotension within a week of birth. Regression analysis after matching showed that 1-minute Apgar score, neonatal cardiac massage or epinephrine administration, symptomatic patent ductus arteriosus, early onset sepsis, and chorioamnionitis were significantly associated with hypotension. In the hypotension group, mortality, grade 3 or higher intraventricular hemorrhage, periventricular leukomalacia, and moderate to severe bronchopulmonary dysplasia rates were significantly higher after the matching for gestational age and SGA. Hypotension during the first postnatal week is very closely related to the prematurity and the condition of the infant shortly after birth. Regular prenatal care including careful monitoring and appropriate neonatal resuscitation are very crucial to decrease the risk of hypotension in the early stages of life.

Maximum vasoactive-inotropic score and mortality in extremely premature, extremely low birth weight infants

OBJECTIVE

To determine the relationship between maximum vasoactive-inotropic (VIS^max) and mortality in extremely premature (<29 weeks completed gestation), extremely low birth weight (ELBW, <1000 g) infants.

STUDY DESIGN

Single center, retrospective, and observational cohort study.

RESULTS

We identified 436 ELBW, <29 week, inborn infants cared for during the study period. Compared to infants with VIS^max of 0, the frequency of mortality based on VIS^max ranged from 3.3-fold to 46.1-fold. VIS^max > 30 was associated with universal mortality. Multivariable modeling that included gestational age, birth weight, and VIS^max revealed significant utility to predict mortality with negative predictive value of 87.0% and positive predictive value of 84.8% [adjusted AUROC: 0.90, (0.86-0.94)] among patients that received vasoactive-inotropic treatment.

CONCLUSION

VIS^max is an objective measure of hemodynamic/cardiovascular support that was directly associated with mortality in extremely premature ELBW infants. The VIS^max represents an important step towards neonatal precision medicine and risk stratification of extremely premature ELBW infants.

Hypotension in Preterm Infants (HIP) randomised trial

OBJECTIVE

To determine whether restricting the use of inotrope after diagnosis of low blood pressure (BP) in the first 72 hours of life affects survival without significant brain injury at 36 weeks of postmenstrual age (PMA) in infants born before 28 weeks of gestation.

DESIGN

Double-blind, placebo-controlled randomised trial. Caregivers were masked to group assignment.

SETTING

10 sites across Europe and Canada.

PARTICIPANTS

Infants born before 28 weeks of gestation were eligible if they had an invasive mean BP less than their gestational age that persisted for ≥15 min in the first 72 hours of life and a cerebral ultrasound free of significant (≥ grade 3) intraventricular haemorrhage.

INTERVENTION

Participants were randomly assigned to saline bolus followed by either a dopamine infusion (standard management) or placebo (5% dextrose) infusion (restrictive management).

PRIMARY OUTCOME

Survival to 36 weeks of PMA without severe brain injury.

RESULTS

The trial terminated early due to significant enrolment issues (7.7% of planned recruitment). 58 infants were enrolled between February 2015 and September 2017. The two groups were well matched for baseline variables. In the standard group, 18/29 (62%) achieved the primary outcome compared with 20/29 (69%) in the restrictive group (p=0.58). Additional treatments for low BP were used less frequently in the standard arm (11/29 (38%) vs 19/29 (66%), p=0.038).

CONCLUSION

Though this study lacked power, we did not detect major differences in clinical outcomes between standard or restrictive approach to treatment. These results will inform future studies in this area.

TRIAL REGISTRATION NUMBER

NCT01482559, EudraCT 2010-023988-17.

Biomarkers for the Diagnosis of Neonatal Sepsis

Neonatal sepsis is a major cause of morbidity and mortality in neonates and is challenging to diagnose. Infants manifest nonspecific clinical signs in response to sepsis; these signs may be caused by noninfectious conditions. Time to antibiotics affects neonatal sepsis outcome, so clinicians need to identify and treat neonates with sepsis expeditiously. Clinicians use serum biomarkers to measure inflammation and infection and assess the infant's risk of sepsis. However, current biomarkers lack sufficient sensitivity or specificity to be consider useful diagnostic tools. Continued research to identify novel biomarkers as well as novel ways of measuring them is sorely needed.

Efficacy of Low-Dose Epinephrine Continuous Infusion in Neonatal Intensive Care Unit Patients

OBJECTIVES

Although epinephrine is used in the neonatal intensive care unit, few data exist on efficacy of doses <0.05 mcg/kg/min. This study evaluates the efficacy and safety of low-dose epinephrine continuous infusion at doses <0.05 mcg/kg/min in infants.

METHODS

Single-center, retrospective review of hypotensive infants from 2011-2018. Charts were reviewed for initial and maximum epinephrine doses, additional vasoactive agents, short-term efficacy, and adverse effects. The primary outcome was percentage of patients initiated on low-dose epinephrine whose dose did not require titration to ≥0.05 mcg/kg/min.

RESULTS

A total of 115 patients met study criteria with 131 distinct occurrences of low-dose epinephrine initiation. Most patients were unresponsive to other vasopressors at the time of epinephrine initiation. The median (IQR) starting dose of low-dose epinephrine was 0.01 (0.01-0.04) mcg/kg/min and median (IQR) maximum dose was 0.04 (0.02-0.08) mcg/kg/min. Fifty-five percent were responders. Patients in this cohort demonstrated significant improvement of blood pressure and urine output (p < 0.001) without adverse effects.

CONCLUSIONS

Low-dose epinephrine infusion may be considered as an alternative treatment to standard starting doses in hypotensive neonatal intensive care unit patients.

Cardiovascular Pharmacological Support Among Preterm Infants in Chinese Referral Center Neonatal Intensive Care Units

Objective: To describe cardiovascular pharmacological support in infants born at <34 weeks' gestation within the first postnatal week in Chinese neonatal intensive care units (NICUs). Design: A secondary analysis of data from a multicenter randomized controlled study (REIN-EPIQ). A questionnaire regarding cardiovascular support practices was also completed by all participating NICUs. Setting: Twenty-five tertiary hospitals from 19 provinces in China. Patients: All infants born at <34 weeks' gestation and admitted to participating NICUs within the first postnatal week from May 2015 to April 2018 were included. Infants who were discharged against medical advice were excluded. Measures and Main Results: Among the 26,212 preterm infants <34 weeks, 16.1% received cardiovascular pharmacological support. The use rates increased with decreasing gestational age and birth weight, with 32.5% among infants <28 weeks and 35.9% among infants <1,000 g. Cardiovascular pharmacological support was independently associated with higher risks of death (aOR 2.8; 95% CI 2.4-3.3), severe intraventricular hemorrhage (IVH) (aOR 2.1; 95% CI 1.8-2.5) and bronchopulmonary dysplasia (BPD) (aOR 2.2; 95% CI 2.0-2.5). Overall 63.1% courses of cardiovascular pharmacological support were >3 days. Prolonged cardiovascular pharmacological support (>3 days) was independently associated with lower rates of survival without morbidity in very-low-birth-weight infants, compared with infants with shorter durations. Dopamine was the most commonly used cardiovascular agent. The cardiovascular pharmacological support rates varied from 1.9 to 65.8% among the participating NICUs. Conclusions: The rate of cardiovascular pharmacological support within the first postnatal week was high with prolonged durations in Chinese NICUs. Marked variation in cardiovascular support existed among participating NICUs. Cardiovascular pharmacological support during the early postnatal period, especially prolonged, may be associated with adverse neonatal outcomes. Clinical Trial Registration: The original trial was registered as "Reduction of Infection in Neonatal Intensive Care Units using the Evidence-based Practice for Improving Quality" (ID: NCT02600195) on clinicaltrials.gov. https://clinicaltrials.gov/ct2/show/NCT02600195?term=NCT02600195&draw=2&rank=1.

Propofol for endotracheal intubation in neonates: a dose-finding trial

OBJECTIVE

To find propofol doses providing effective sedation without side effects in neonates of different gestational ages (GA) and postnatal ages (PNA).

DESIGN AND SETTING

Prospective multicentere dose-finding study in 3 neonatal intensive care units.

PATIENTS

Neonates with a PNA <28 days requiring non-emergency endotracheal intubation.

INTERVENTIONS

Neonates were stratified into 8 groups based on GA and PNA. The first 5 neonates in every group received a dose of 1.0 mg/kg propofol. Based on sedative effect and side effects, the dose was increased or decreased in the next 5 patients until the optimal dose was found.

MAIN OUTCOME MEASURES

The primary outcome was the optimal single propofol starting dose that provides effective sedation without side effects in each age group.

RESULTS

After inclusion of 91 patients, the study was prematurely terminated because the primary outcome was only reached in 13% of patients. Dose-finding was completed in 2 groups, but no optimal propofol dose was found. Effective sedation without side effects was achieved more often after a starting dose of 2.0 mg/kg (28%) than after 1.0 mg/kg (3%) and 1.5 mg/kg (9%). Propofol-induced hypotension occurred in 59% of patients. Logistic regression analyses showed that GA and PNA did not predict effective sedation or the occurrence of hypotension.

CONCLUSIONS

Effective sedation without side effects is difficult to achieve with propofol and the optimal dose in different age groups of neonates could not be determined. The sedative effect of propofol and the occurrence of hypotension are unpredictable and show large inter-individual variability in the neonatal population.

Fluid Therapy: Friend or Foe?

Many questions surround fluid bolus therapy and subsequent fluid management in neonatal critical care as they do in pediatric and adult critical care. This review explores the known key clinical aspects of fluid bolus therapy and fluid balance in the first 7 days of life and provides suggestions for further work in this area. It draws on the pediatric and adult critical care literature to provide thought-provoking data around the potential harms of excessive intravenous fluids, which may prove relevant to neonatology. Current data suggest that fluid bolus therapy and early-life positive fluid balance in neonates may be associated with harm.

Clinical Trials in Hemodynamic Support: Past, Present, and Future

Managing low blood flow states in the preterm population remains a challenge in neonatal clinical care. The heterogeneity of the trials to date and the relatively low number of infants enrolled, in addition to a desire to oversimplify the underlying pathophysiology, have contributed to an inability to draw meaningful conclusions to direct clinical care. This article reviews the current literature on this topic in the preterm population and outlines the challenges that have been encountered in performing such trials. Alternative studies are proposed, based on the lessons learned over the past number of years.

Corticosteroids for Neonatal Hypotension

Several limitations and controversies surround the definition of hypotension; however, it remains one of the most common problems faced by neonates. Approximately 15% to 30% of neonates with hypotension fail to respond to volume and/or vasopressor or inotropes. They are considered to have refractory hypotension. Although it is thought to have multiple causes, absolute and relative adrenal insufficiency is considered as the main reason for refractory hypotension. This article focuses on the role of adrenal insufficiency in causing refractory hypotension in preterm and term infants, the different options of corticosteroids available, and their risk/benefit profiles.

Heart Rate Variability during Periods of Low Blood Pressure as a Predictor of Short-Term Outcome in Preterms

Efficient management of low blood pressure (BP) in preterm neonates remains challenging with a considerable variability in clinical practice. The ability to assess preterm wellbeing during episodes of low BP will help to decide when and whether hypotension treatment should be initiated. This work aims to investigate the relationship between heart rate variability (HRV), BP and the short-term neurological outcome in preterm infants less than 32 weeks gestational age (GA). The predictive power of common HRV features with respect to the outcome is assessed and shown to improve when HRV is observed during episodes of low mean arterial pressure (MAP) - with a single best feature leading to an AUC of 0.87. Combining multiple features with a boosted decision tree classifier achieves an AUC of 0.97. The work presents a promising step towards the use of multimodal data in building an objective decision support tool for clinical prediction of short-term outcome in preterms who suffer episodes of low BP.

Prediction of short-term health outcomes in preterm neonates from heart-rate variability and blood pressure using boosted decision trees

BACKGROUND AND OBJECTIVE

Efficient management of low blood pressure (BP) in preterm neonates remains challenging with considerable variability in clinical practice. There is currently no clear consensus on what constitutes a limit for low BP that is a risk to the preterm brain. It is argued that a personalised approach rather than a population based threshold is more appropriate. This work aims to assist healthcare professionals in assessing preterm wellbeing during episodes of low BP in order to decide when and whether hypotension treatment should be initiated. In particular, the study investigates the relationship between heart rate variability (HRV) and BP in preterm infants and its relevance to a short-term health outcome.

METHODS

The study is performed on a large clinically collected dataset of 831 h from 23 preterm infants of less than 32 weeks gestational age. The statistical predictive power of common HRV features is first assessed with respect to the outcome. A decision support system, based on boosted decision trees (XGboost), was developed to continuously estimate the probability of neonatal morbidity based on the feature vector of HRV characteristics and the mean arterial blood pressure.

RESULTS

It is shown that the predictive power of the extracted features improves when observed during episodes of hypotension. A single best HRV feature achieves an AUC of 0.87. Combining multiple HRV features extracted during hypotensive episodes with the classifier achieves an AUC of 0.97, using a leave-one-patient-out performance assessment. Finally it is shown that good performance can even be achieved using continuous HRV recordings, rather than only focusing on hypotensive events - this had the benefit of not requiring invasive BP monitoring.

CONCLUSIONS

The work presents a promising step towards the use of multimodal data in providing objective decision support for the prediction of short-term outcome in preterm infants with hypotensive episodes.

Observed and calculated cerebral critical closing pressure are highly correlated in preterm infants

BACKGROUND

Cerebrovascular critical closing pressure (CrCP) is the arterial blood pressure (ABP) at which cerebral blood flow ceases. Preterm ABP is low and close to CrCP. The diastolic closing margin (diastolic ABP minus CrCP) has been associated with intraventricular hemorrhage in preterm infants. CrCP is estimated from middle cerebral artery cerebral blood flow velocity (CBFV) and ABP waveforms. However, these estimations have not been validated due to a lack of gold standard. Direct observation of the CrCP in preterm infants with hypotension is an opportunity to validate synchronously estimated CrCP.

METHODS

ABP and CBFV tracings were obtained from 24 extremely low birth weight infants. Recordings where diastolic CBFV was zero were identified. The gold standard CrCP was delineated using piecewise regression of ABP and CBFV values paired by rank ordering and then estimated using a published formula. The measured and estimated values were compared using linear regression and Bland-Altman analysis.

RESULTS

Linear regression showed a high degree of correlation between measured and calculated CrCP (r² = 0.93).

CONCLUSIONS

This is the first study to validate a calculated CrCP by comparing it to direct measurements of CrCP from preterm infants when ABP is lower than CrCP.

Decision-making at the limit of viability: the Austrian neonatal choice context

BACKGROUND

We aimed to explore the shared decision-making context at the limit of viability (weeks 22-25 of gestation) through analyzing neonatologist's communication strategies with parents and their possible impact on survival and neurodevelopmental impairment (NDI) outcomes.

METHODS

A mixed methods approach was applied where a systematic literature search and in-depth semi-structured interviews with five heads of neonatology departments and one clinical ethicist from the Austrian context were integrated into a literature review. The aim was to identify decision practice models and the choice context specific to Austria.

RESULTS

Professional biases, parental understanding, and the process of information giving were identified as aspects possibly influencing survival and NDI outcomes. Institutions create self-fulfilling prophecies by recommending intensive/palliative care based upon their institutional statistics, yet those vary considerably among high-income countries. Labelling an extremely preterm (EP) infant by the gestational week was shown to skew the estimates for survival while the process of information giving was shown to be subject to framing effect and other cognitive biases.

CONCLUSION

Communication strategies of choice options to parents may have an impact on the way parents decide and hence also on the outcomes of EP infants.

The Use of Cardiotonic Drugs in Neonates

There is a distinct lack of age-appropriate cardiotonic drugs, and adult derived formulations continue to be administered, without evidence-based knowledge on their dosing, safety, efficacy, and long-term effects. Dopamine remains the most commonly studied and prescribed cardiotonic drug in the neonatal intensive care unit (NICU), but evidence of its effect on endorgan perfusion still remains. Unlike adult and pediatric critical care, there are significant gaps in our knowledge on the use of various cardiotonic drugs in various forms of circulatory failure in the NICU.

International, multicentre, observational study of fluid bolus therapy in neonates

AIM

To assess the prevalence, types and indications for fluid bolus therapy in neonates with haemodynamic compromise.

METHODS

This was a pragmatic, international, multicentre observational study in neonatal units across Australasia, Europe and North America with a predefined study period of 10-15 study days per participating neonatal unit between December 2015 and March 2017. Infants ≤28 days of age who received a fluid bolus for the management of haemodynamic compromise (≥10 mL/kg given at ≤6 h) were included.

RESULTS

A total of 163 neonates received a bolus over 8479 eligible patient days in 41 neonatal units. Prevalence of fluid bolus therapy varied between centres from 0 to 28.6% of admitted neonates per day, with a pooled prevalence rate of 1.5% (95% confidence interval 1.1-1.9%). The most common fluid used was 0.9% sodium chloride (129/163; 79%), and the volume of fluid administered was most commonly 10 mL/kg (115/163; 71%) over a median of 30 min (interquartile range 20-60). The most frequent indications were hypotension (n = 56; 34%), poor perfusion (n = 20; 12%) and metabolic acidosis (n = 20; 12%). Minimal or no clinical improvement was reported by clinicians in 66 of 163 cases (40%).

CONCLUSIONS

Wide international variations in types, indications and effects of fluid bolus administration in haemodynamically compromised neonates suggest uncertainty in the risk-benefit profile. This is likely to reflect the lack of robust evidence to support the efficacy of different fluid types, doses and appropriate indications. Together, these highlight a need for further clinically relevant studies.

Blood pressure intervention levels in preterm infants: pilot randomised trial

OBJECTIVE

To examine the feasibility of a trial allocating different blood pressure (BP) intervention levels for treatment in extremely preterm infants.

DESIGN

Three-arm open randomised controlled trial performed between February 2013 and April 2015.

SETTING

Single tertiary level neonatal intensive care unit.

PATIENTS

Infants born <29 weeks' gestation were eligible to participate, if parents consented and they did not have a major congenital malformation.

INTERVENTIONS

Infants were randomised to different levels of mean arterial BP at which they received cardiovascular support: active (<30 mm Hg), moderate (<gestational age mm Hg) or permissive (signs of poor perfusion or <19 mm Hg). Once this threshold was breached, all were managed using the same treatment guideline. BP profiles were downloaded continuously; cardiac output and carotid blood flow were measured at 1 day and 3 days, and amplitude integrated EEG was recorded during the first week. Cranial ultrasound scans were reviewed blind to study allocation.

MAIN OUTCOME MEASURE

Inotrope usage and achieved BP.

RESULTS

Of 134 cases screened, 60 were enrolled, with mean gestation 25.8 weeks (SD 1.5) and birth weight 817 g (SD 190). Invasively measured BP on the first day and inotrope usage were highest in the active and lowest in the permissive arms. There were no differences in haemodynamic or EEG variables or in clinical complications. Predefined cranial ultrasound findings did not differ significantly; no infants in the active arm had parenchymal brain lesions.

CONCLUSION

The BP threshold used to trigger treatment affects the achieved BP and inotrope usage, and it was possible to explore these effects using this study design.

TRIAL REGISTRATION NUMBER

ISRCTN83507686.

Cerebral Oxygenation During Neonatal Intubation-Ancillary Study of the Prettineo-Study

Purpose: This study aimed to describe cerebral Near InfraRed Spectroscopy (NIRS) profiles during neonatal intubation using two different premedication regimens. Methods: Neonates requiring non-emergency intubation were enrolled in an ancillary study, conducted in two French Neonatal Intensive Care Units participating in a larger on-going multicenter, double blind, randomized, controlled trial. Patients were randomly assigned to the "atropine-propofol" (Prop) group or the "atropine-atracurium-sufentanil" (SufTrac) group. Regional cerebral oxygen saturation (rScO₂), pulse oxymetry (SpO₂), mean arterial blood pressure (MABP), and transcutaneous partial pressure of carbon dioxide (TcPCO₂) were collected at 9 predefined time points from 1 min before to 60 min after the first drug injection. The two primary outcomes were a decrease in rScO₂ value >20% from baseline and a decrease in fractional cerebral tissue oxygen extraction (FTOE) value >10% from baseline, at any time point. Secondary outcomes included physiological parameters changes over time and correlations between mean arterial blood pressure, and FTOE at different time points. Descriptive results were obtained and exploratory statistical analyses were performed for 24 included patients. Results: rScO₂ decreased in 5/11 (46%) infants from the Prop group and 10/13 (77%) from the SufTrac group (p = 0.11); FTOE decreased in 10/11 (91%) infants from the Prop group, and 12/13 (92%) from the SufTrac group (p = 0.90). rScO₂ values decreased over time in both groups, whereas FTOE's pattern appeared more stable. SpO₂ and transcutaneous TcPCO₂ seemed more preserved in the Prop group while MABP seemed more preserved in the SufTrac group. No important correlation was observed between MABP and FTOE (r = 0.08 to 0.12 across the time points). Conclusion: Our results suggest a frequent decrease in cerebral oxygenation without obvious impairment in cerebral autoregulation during neonatal intubation with premedication. This study confirms the feasibility and the informative value of cerebral NIRS monitoring in this setting. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT02700893.

Hypotension in small preterms: what does it mean?

Introduction: Small preterms often have low blood pressure readings in the first few days of life. However, what is hypotension in preterms? Should there be an aggressive approach to its management? What are the immediate and long-term side effects of powerful medications? Alternatively, could a low blood pressure be accepted instead? Materials and methods: Data were collected from files of all live babies with gestational age (GA) between 23^0/7 and 31^6/7 weeks over two different periods: years 2000-2004 and 2008-2012. Results: Our data show that, despite extremely low gestational age (ELGA)/extremely low birth weight (ELBW) neonates, almost half of these tiny babies have neither low mean arterial pressure (MAP) readings nor clinical signs of impaired perfusion. Yet, many of them are, variously treated or not, depending on individual decisions, rather than on sound evidence. Discussion: We suggest, should it be required to treat persistent hypotension, rather than treating just a low MAP recording, to address the whole issue of hypotension in the overall picture of clinical settings; we to assess organ dysfunction caused by low output and use the least aggressive measures, preferably within written protocols, tailored to the given unit, but equally, sufficiently flexible to individual babies. Furthermore, allow for "permissive hypotension" especially if transient, in the absence of clinical signs of hypoperfusion, with normal superior vena cava (SVC) flow, normal cardiac output, and normal brain scanning with normal cerebral Doppler flows. Whether treating hypotension, by whichever definition, "per se", will make any difference to both, immediate and late outcomes; in the end, treating remains open to questioning and calls for careful follow-up of these very susceptible preterms.

Coupling between mean blood pressure and EEG in preterm neonates is associated with reduced illness severity scores

Hypotension or low blood pressure (BP) is a common problem in preterm neonates and has been associated with adverse short and long-term neurological outcomes. Deciding when and whether to treat hypotension relies on an understanding of the relationship between BP and brain functioning. This study aims to investigate the interaction (coupling) between BP and continuous multichannel unedited EEG recordings in preterm infants less than 32 weeks of gestational age. The EEG was represented by spectral power in four frequency sub-bands: 0.3-3 Hz, 3-8 Hz, 8-15 Hz and 15-30 Hz. BP was represented as mean arterial pressure (MAP). The level of coupling between the two physiological systems was estimated using linear and nonlinear methods such as correlation, coherence and mutual information. Causality of interaction was measured using transfer entropy. The illness severity was represented by the clinical risk index for babies (CRIB II score) and contrasted to the computed level of interaction. It is shown here that correlation and coherence, which are linear measures of the coupling between EEG and MAP, do not correlate with CRIB values, whereas adjusted mutual information, a nonlinear measure, is associated with CRIB scores (r = -0.57, p = 0.003). Mutual information is independent of the absolute values of MAP and EEG powers and quantifies the level of coupling between the short-term dynamics in both signals. The analysis indicated that the dominant causality is from changes in EEG producing changes in MAP. Transfer entropy (EEG to MAP) is associated with the CRIB score (0.3-3 Hz: r = 0.428, p = 0.033, 3-8 Hz: r = 0.44, p = 0.028, 8-15 Hz: r = 0.416, p = 0.038) and indicates that a higher level of directed coupling from brain activity to blood pressure is associated with increased illness in preterm infants. This is the first study to present the nonlinear measure of interaction between brain activity and blood pressure and to demonstrate its relation to the initial illness severity in the preterm infant. The obtained results allow us to hypothesise that the normal wellbeing of a preterm neonate can be characterised by a nonlinear coupling between brain activity and MAP, whereas the presence of weak coupling with distinctive directionality of information flow is associated with an increased mortality rate in preterms.

Circulatory Insufficiency and Hypotension Related to the Ductus Arteriosus in Neonates

The biological role of the ductus arteriosus (DA) in neonates varies from an innocent bystander role during normal postnatal transition, to a supportive role when there is compromise to either systemic or pulmonary blood flow, to a pathological state in the presence of hemodynamically significant systemic to pulmonary shunts, as occurs in low birth weight infants. Among a wide array of clinical manifestations arising due to the ductal entity, systemic circulatory insufficiency and hypotension are of significant concern as they are particularly challenging to manage. An understanding of the physiologic interplay between the DA and the circulatory system is the key to developing appropriate targeted therapeutic strategies. In this review, we discuss the relationship of systemic hypotension to the DA, emphasizing the importance of critical thinking and a precise individual approach to intensive care support. We particularly focus on the variable states of hypotension arising directly due to a hemodynamically significant DA or seen in the period following successful surgical ligation. In addition, we explore the mechanistic contributions of the ductus to circulatory insufficiency that may manifest during the transitional period, states of maladapted transition (such as acute pulmonary hypertension of the newborn), and congenital heart disease (both ductal dependent and non-ductal dependent lesions). Understanding the dynamic modulator role of the ductus according to the ambient physiology enables a more precise approach to management. We review the pathophysiology, clinical manifestations, diagnosis, monitoring, and therapeutic intervention for the spectrum of DA-related circulatory compromise.

Extensive use of vasodilator agents and functional echocardiography to monitor extremely-low-birth-weight infants in Japan

National surveys were conducted in Japan to assess the current practices for circulatory management of extremely-low-birth-weight infants (ELBWIs) in acute phases. Approximately 80 and 100 institutions were surveyed in 2006 and 2011, respectively. Echocardiography was identified as an important diagnostic tool at 95% of the surveyed institutions. Furthermore, 74% of the institutions survey in 2011 used vasodilator agents. In 2011, the mean velocity of circumferential fiber shortening (mVcfc) and left ventricular end-systolic wall stress (ESWS) were used by 60% of the surveyed institutions to evaluate the relationship between afterload of the left ventricle and left ventricular contractility. Overall, the data collected from these national surveys clarified the current practices for circulatory management of ELBWIs in Japan, particularly the use of echocardiography and cardiovascular agents, including catecholamines and vasodilators.

Management of Neonatal Hypotension

Hypotension is a common problem in neonates with complex underlying pathophysiology. Although treatment of low blood pressure is common, clinicians must use all available information to target neonates with compromised perfusion. Pharmacotherapy should be tailored to the specific physiologic perturbations of the individual neonate. Dopamine is the most commonly utilized agent and may be the most appropriate agent for septic shock with low diastolic blood pressure. However, alternative therapies should be considered for other etiologies of hypotension, including milrinone and vasopressin for persistent pulmonary hypertension of the newborn and dobutamine for patent ductus arteriosus. Additional studies are required to refine the approach to neonatal hypotension and document the long-term outcomes of treated neonates.

Integrated Evaluation of Neonatal Hemodynamics Program Optimizing Organ Perfusion and Performance in Critically Ill Neonates, Part 1: Understanding Physiology of Neonatal Hemodynamics

Integrated evaluation of neonatal hemodynamics is the integration of information obtained by echocardiography, clinical evaluation, and biochemical markers, in addition to the clinical information obtained from noninvasive and invasive monitoring of blood pressure and arterial and tissue oxygenation, leading to the formulation of a medical recommendation. This review will focus on the physiology of cardiovascular dynamics and oxygen delivery.

Pathophysiology of the Cardiovascular System and Neonatal Hypotension

Hypotension is common in low birth weight neonates and less common in term newborns and is associated with significant morbidity and mortality. Determining an adequate blood pressure in neonates remains challenging for the neonatal nurse because of the lack of agreed-upon norms. Values for determining norms for blood pressure at varying gestational and postnatal ages are based on empirical data. Understanding cardiovascular pathophysiology, potential causes of hypotension, and assessment of adequate perfusion in the neonatal population is important and can assist the neonatal nurse in the evaluation of effective blood pressure. This article reviews cardiovascular pathophysiology as it relates to blood pressure and discusses potential causes of hypotension in the term and preterm neonate. Variation in management of hypotension across centers is discussed. Underlying causes and pathophysiology of hypotension in the neonate are described.

Circulatory Management Focusing on Preventing Intraventricular Hemorrhage and Pulmonary Hemorrhage in Preterm Infants

The goal of modern neonatal care of extremely preterm infants is to reduce mortality and long-term neurological impairments. Preterm infants frequently experience cerebral intraventricular or pulmonary hemorrhage, which usually occurs within 72 hours after birth and can lead to long-term neurological sequelae and mortality. These serious hemorrhagic complications are closely related to perinatal hemodynamic changes, including an increase in the afterload on the left ventricle of the heart after the infant is separated from the placenta, and an increased preload from a left-to-right shunt caused by a hemodynamically significant patent ductus arteriosus (PDA). The left ventricle of a preterm myocardium has limited ability to respond to such an increase in afterload and preload, and this can result in cardiac dysfunction and hemodynamic deterioration. We suggest that delayed umbilical cord clamping or umbilical cord milking to maintain optimal blood pressure and systemic blood flow (SBF), careful assessment to keep the afterload at an acceptable level, and a strategy of early targeted treatment of significant PDA to improve perfusion during this critical time period may reduce or prevent these serious complications in preterm infants.

Blood pressure and aEEG in the 96h after birth and correlations with neurodevelopmental outcome in extremely preterm infants

BACKGROUND

The management of hypotension immediately after the birth of preterm infants is controversial.

AIM

To investigate the relationship between blood pressure (BP), amplitude-integrated electroencephalography (aEEG), and neurodevelopmental outcome in extremely preterm infants.

METHODS

BP and aEEG were monitored for 96h after birth in 36 infants born at <27weeks gestation. aEEG data were analyzed with Burdjalov scores. Correlations of aEEG findings with BP and several clinical characteristics, including the Score for Neonatal Acute Physiology, Perinatal Extension-II (SNAPPE-II) were explored. A subgroup analysis of BP, aEEG activity, and neurodevelopmental outcome at 18-22months corrected age was also performed. Poor outcome was defined as death or a developmental quotient <70.

RESULTS

Multiple regression analyses revealed no association between BP during the first 48h after birth and aEEG activity. However, BP 48-96h after birth was significantly associated with simultaneous aEEG activity (p<0.001). Within 48h after birth, SNAPPE-II was significantly associated with aEEG activity. Outcome was assessed in 32 infants; 24 and 8 of whom had good and poor outcomes, respectively. aEEG activity was significantly lower in neonates with a poor outcome than those with a good outcome (<0.001). No significant differences in outcome were observed for BP.

CONCLUSION

The activity of aEEG was associated with illness severity during the first 48h after birth. After 48h, there was no effect of illness severity but there was an association with BP. We do not know if hypotension results in a poor outcome. However, aEEG activity was associated with neurodevelopmental outcome.

Morbidity and mortality of preterm infants less than 26 weeks of gestational age

BACKGROUND

Extreme preterm infants have a high risk of morbidity and mortality. Newborns delivered between 23+0 and 25+6 weeks, are considered to be in the "gray zone" and have uncertain prognosis. For these children medical decision-making becomes complex and controversial. The present study intends to evaluate the neonatal morbidity and mortality of preterm infants born between 23 weeks and 25+6 weeks of gestational age.

METHODS

A retrospective study was conducted including all inborn preterm infants, with a gestational age between 23+0 and 25+6 weeks, admitted to a level IIIC NICU, between January 1st, 1996 and December 31st, 2014.

RESULTS

A total of 72 preterm neonates were included, 18.1% had a full cycle of antenatal steroids. The most frequent major morbidities were RDS (95.4%), patent ductus arteriosus (81.3%), sepsis (55.7%, being 19.7% early sepsis, and 36.1% late sepsis), intraventricular hemorrhage (34.4%), retinopathy of prematurity (21.9%) and necrotizing enterocolitis (10.9%). Fifty-four (75%) children died. The only factor adjusted to age associated with high mortality founded was hypotension (OR=4.99, P<0.019). Morbidity at discharge was: severe bronchopulmonary dysplasia (77.8%), retinopathy of prematurity (72.2%), intraventricular hemorrhage (16.7%), cystic periventricular leukomalacia (11.1%), and sequalae of necrotizing enterocolitis (5.6%).

CONCLUSIONS

The survival rate was 25% and a high morbidity at discharge was observed, which leave us with the huge responsibility to improve this result in a near future. Extreme prematurity is still a very controversial and complex issue and particular challenge for neonatologists. The use of antenatal steroid in the more immature preterm infants should be encouraged.

Definitions of cardiovascular insufficiency and relation to outcomes in critically ill newborn infants

BACKGROUND

We previously reported on the overall incidence, management, and outcomes in infants with cardiovascular insufficiency (CVI). However, there are limited data on the relationship of the specific different definitions of CVI to short-term outcomes in term and late preterm newborn infants.

OBJECTIVE

This study aims to evaluate how four definitions of CVI relate to short-term outcomes and death.

STUDY DESIGN

The previously reported study was a multicenter, prospective cohort study of 647 infants ≥ 34 weeks gestation admitted to a Neonatal Research Network (NRN) newborn intensive care unit (NICU) and mechanically ventilated (MV) during their first 72 hours. The relationship of five short-term outcomes at discharge and four different definitions of CVI were further analyzed.

RESULTS

All the four definitions were associated with greater number of days on MV and days on O2. The definition using a threshold blood pressure (BP) measurement alone was not associated with days of full feeding, days in the NICU or death. The definition based on the treatment of CVI was associated with all the outcomes including death.

CONCLUSIONS

The definition using a threshold BP alone was not consistently associated with adverse short-term outcomes. Using only a threshold BP to determine therapy may not improve outcomes.

Challenges in Treating Low Blood Pressure in Preterm Infants

Whilst the prevalence of low blood pressure in preterm infants seems to have fallen over the last number of years, the problem is still frequently encountered in the neonatal intensive care unit and many babies continue to receive intervention. Great variability in practice persists, with a significant number of extremely low gestational age newborns in some institutions receiving some form of intervention, and in other units substantially less. A great degree of this variability relates to the actual criteria used to define hypotension, with some using blood pressure values alone to direct therapy and others using a combination of clinical, biochemical and echocardiography findings. The choice of intervention remains unresolved with the majority of centres continuing to administer volume followed by dopamine as a first line inotrope/vasopressor agent. Despite over 40 years of use there is little evidence that dopamine is of benefit both in the short term and long-term. Long-term follow up is available in only two randomised trials, which included a total of 99 babies. An under recognized problem relates to the administration of inotrope infusions in very preterm infants. There are no pediatric specific inotrope formulations available and so risks of errors in preparation and administration remain. This manuscript outlines these challenges and proposes some potential solutions.

Prospective surveillance of antibiotic use in the neonatal intensive care unit: results from the SCOUT study

BACKGROUND

Prolonged or unnecessary antibiotic use is associated with adverse outcomes in neonates. Our objectives were to quantify all antibiotic use in a Level-III neonatal intensive care unit and to identify scenarios where their use could be reduced.

METHODS

Surveillance and evaluation of all antibiotic use provided to every infant admitted to a Level-III neonatal intensive care unit from 10/3/11 to 11/30/12 was performed. Types of antibiotics, reasons for their initiation, discontinuation and duration, as well as clinical, laboratory and outcome data were recorded. Antibiotic use was quantified by days of therapy (DOT) per 1000 patient-days (PD).

RESULTS

A total of 1607 infants were included. The total antibiotic use was 9165 DOT (343.2 DOT/1000 PD; 5.7 DOT/infant). Seventy-two percent of infants received 1 (43%) or more (29%) courses of antibiotics. Gentamicin (46%), ampicillin (39%) and oxacillin (8%) were the most frequently used agents. Ninety-four percent of antibiotic use (323 DOT/1000 PD) was empiric therapy for suspected infection. Sixty-three percent (216.2 DOT/1000 PD) was discontinued at approximately 48 hours when cultures were sterile (68%>48 hours, 32%≤48 hours). Twenty-six percent of all antibiotic use (89.4 DOT/1000 PD) was therapy for ≥5 days despite sterile cultures; pneumonia (16%) and "culture-negative" sepsis (8%) were the major contributors. Five percent (17.4 DOT/1000 PD) of antibiotic use was for culture-proven sepsis, 5% (16.6 DOT/1000 PD) was penicillin prophylaxis for group B Streptococcus and 1% (3.5 DOT/1000 PD) was preprocedural prophylaxis.

CONCLUSIONS

Narrow-spectrum therapy accounted for >92% of antibiotic use and would not be monitored by most stewardship programs. Only 5% of antibiotic usage was due to culture-proven infection. Pneumonia and "culture-negative" sepsis were frequent reasons for prolonged therapy; further study of these conditions may allow reduction in treatment duration.

Antimicrobial stewardship in the NICU

There are unique challenges to antimicrobial stewardship in neonatal intensive care units (NICUs). Diagnosis of infection is difficult as neonates can have nonspecific signs and symptoms. Between and within NICUs, significant variation exists in the treatment duration of suspected sepsis and pneumonia. Development of multidisciplinary teams and meaningful metrics are essential for sustainable antibiotic stewardship. Potential stewardship interventions include optimizing culturing techniques, guiding empiric therapy by NICU-specific antibiograms, using ancillary laboratory tests, and promptly discontinuing therapy once infection is no longer suspected. Use of large neonatal databases can be used to benchmark antibiotic use and conduct comparative effectiveness research.

Incidence, management, and outcomes of cardiovascular insufficiency in critically ill term and late preterm newborn infants

OBJECTIVE

The objective of this study was to characterize the incidence, management, and short-term outcomes of cardiovascular insufficiency (CVI) in mechanically ventilated newborns, evaluating four separate prespecified definitions.

STUDY DESIGN

Multicenter, prospective cohort study of infants ≥34 weeks gestational age (GA) and on mechanical ventilation during the first 72 hours. CVI was prospectively defined as either (1) mean arterial pressure (MAP) < GA; (2) MAP < GA + signs of inadequate perfusion; (3) any therapy for CVI; or (4) inotropic therapy. Short-term outcomes included death, days on ventilation, oxygen, and to full feedings and discharge.

RESULTS

Of 647 who met inclusion criteria, 419 (65%) met ≥1 definition of CVI. Of these, 98% received fluid boluses, 36% inotropes, and 17% corticosteroids. Of treated infants, 46% did not have CVI as defined by a MAP < GA ± signs of inadequate perfusion. Inotropic therapy was associated with increased mortality (11.1 vs. 1.3%; p < 0.05).

CONCLUSION

More than half of the infants met at least one definition of CVI. However, almost half of the treated infants met none of the definitions. Inotropic therapy was associated with increased mortality. These findings can help guide the design of future studies of CVI in newborns.

Impact of perinatal factors on continuous early monitoring of brain electrocortical activity in very preterm newborns by amplitude-integrated EEG

BACKGROUND

Amplitude-integrated electroencephalogram (aEEG) is increasingly used for neuromonitoring in preterms. We aimed to quantify the effects of gestational age (GA), postnatal age (PNA), and other perinatal factors on the development of aEEG early after birth in very preterm newborns with normal cerebral ultrasounds.

METHODS

Continuous aEEG was prospectively performed in 96 newborns (mean GA: 29.5 (range: 24.4-31.9) wk, birth weight 1,260 (580-2,120) g) during the first 96 h of life. aEEG tracings were qualitatively (maturity scores) and quantitatively (amplitudes) evaluated using preestablished criteria.

RESULTS

A significant increase in all aEEG measures was observed between day 1 and day 4 and for increasing GA (P < 0.001). The effect of PNA on aEEG development was 6.4- to 11.3-fold higher than that of GA. In multivariate regression, GA and PNA were associated with increased qualitative and quantitative aEEG measures, whereas small-for-GA status was independently associated with increased maximum aEEG amplitude (P = 0.003). Morphine administration negatively affected all aEEG measures (P < .05), and caffeine administration negatively affected qualitative aEEG measures (P = 0.02).

CONCLUSION

During the first few days after birth, aEEG activity in very preterm infants significantly develops and is strongly subjected to the effect of PNA. Perinatal factors may alter the early aEEG tracing and interfere with its interpretation.