Neonatal Blood Pressure Standards: What Is "Normal"?

Continuous non-invasive measurement of cardiac output in neonatal intensive care using regional impedance cardiography: a prospective observational study

OBJECTIVES

To compare agreement between echocardiography and regional impedance cardiography (RIC)-derived cardiac output (CO), and to construct indicative normative ranges of CO for gestational age groups.

DESIGN, SETTING AND PARTICIPANTS

Prospective cohort observational study performed in a tertiary centre in London, UK, including neonates born between 25 and 42 weeks' gestational age.

EXPOSURES

Neonates on the postnatal ward had 2 hours of RIC monitoring; neonates in intensive care had RIC monitoring for the first 72 hours, then weekly for 2 hours, with concomitant echocardiography measures.

MAIN OUTCOMES AND MEASURES

RIC was used to measure CO continuously. Statistical analyses were performed using R (V.4.2.2; R Core Team 2022). RIC-derived CO and echocardiography-derived CO were compared using Pearson's correlations and Bland-Altman analyses. Differences in RIC-derived CO between infants born extremely, very and late preterm were assessed using analyses of variance and mixed-effects modelling.

RESULTS

127 neonates (22 extremely, 46 very, 29 late preterm and 30 term) were included. RIC and echocardiography-measured weight-adjusted CO were correlated (r=0.62, p<0.001) with a Bland-Altman bias of -31 mL/min/kg (limits of agreement -322 to 261 mL/min/kg). The RIC-derived CO fell over 12 hours, then increased until 72 hours after birth. The 72-hour weight-adjusted mean CO was higher in extremely preterm (424±158 mL/min/kg) compared with very (325±131 mL/min/kg, p<0.001) and late preterm (237±81 mL/min/kg, p<0.001) neonates; this difference disappeared by 2-3 weeks of age.

CONCLUSIONS

RIC is valid for continuous, non-invasive CO measurement in neonates. Indicative normative CO ranges could help clinicians to make more informed haemodynamic management decisions, which should be explored in future studies.

TRIAL REGISTRATION NUMBER

NCT04064177.

Blood pressure normative values in preterm infants during postnatal transition

BACKGROUND

The normative blood pressure values in preterm infants still not well defined during postnatal transition. We aimed to create normative blood pressure (BP) reference values in preterm infants <29 weeks gestational age recorded hourly during the postnatal transition.

METHODS

We included only data from hemodynamically stable newborns. Only BP values measured by umbilical arterial catheter (UAC) were included. The regression model showed that only gestational age and postnatal age in hours determine the BP.

RESULTS

We included 206 out of 547 admitted preterm infants. The BP increases with increasing gestational ages and overtime during the postnatal transition. We constructed 5 BP centile values for each gestational group. BP histograms show that the BP most of the time fluctuated between the 5th and 75th centile values, particularity during day one of life.

CONCLUSIONS

The BP trend values gradually increase in stable preterm infants during the postnatal transition, and preterm infants who do not follow this trend might require hemodynamics assessment.

IMPACT

The normative blood pressure is increasing gradually during the first 3 days after birth and is different with gestational ages. This is first normative blood pressure centile values in stable preterm infant and based on invasive blood pressure monitoring. The data enable more accurate monitoring of hemodynamics in preterm infants during postnatal transition.

Myocardial Work for Dynamic Monitoring of Myocardial Injury in Neonatal Asphyxia

To assess the value of parameters of myocardial work for dynamic monitoring of myocardial injury after neonatal asphyxia. Fifty-three neonates with asphyxia admitted within 24 h after delivery were divided into a mild asphyxia group (n = 40) and severe asphyxia group (n = 13). Echocardiography was performed within 24 h post-birth, within 72 h post-birth (48 h after first echo), and during recovery. The left ventricular ejection fraction on M-mode echocardiography and by Simpson's biplane method (LVEF and Bi-EF, respectively), stroke volume (SV), cardiac output (CO), cardiac index (CI), global longitudinal strain (GLS), global work index (GWI), global constructive work (GCW), and other parameters were measured. Echocardiographic indicators were compared between groups and over time. GWI was significantly increased at 72 h in the mild asphyxia group (P < 0.05) but showed no significant change over time in the severe asphyxia group (P > 0.05). While GCW increased significantly over time in both groups (P < 0.05), it increased earlier in the mild asphyxia group. Time and grouping factors had independent effects on GWI and GCW (P > 0.05). The characteristics of differences in GWI and GCW between the two groups were different from those for LVEF, Bi-EF, SV, CO, CI, and GLS and their change characteristics with improvement from treatment. GWI and GCW changed significantly during recovery from neonatal asphyxia, and their change characteristics differed between mild and severe asphyxia cases. Myocardial work parameters can be used as valuable supplements to traditional indicators of left ventricular function to dynamically monitor the recovery from myocardial injury after neonatal asphyxia.

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.

Evaluation of quality of care in neonatal anesthesia using a bundle of intraoperative parameters

BACKGROUND

Maintenance of physiological homeostasis is key in the safe conduct of pediatric anesthesia. Achieving this goal is especially difficult in neonatal surgery.

AIMS

The first aim was to document the absolute number of seven intraoperative parameters monitored during anesthesia in neonates undergoing gastroschisis surgery. The second aims were to determine the frequency of monitoring of each of these intraoperative parameters as well as the proportion of cases in which each parameter was both monitored and maintained within a pre-defined range.

METHODS

This retrospective observational analysis includes data from 53 gastroschisis surgeries performed at Caen University Hospital (2009-2020). Seven intraoperative parameters were analyzed. First, we assessed if the intraoperative parameters were monitored or not. Second, when monitored, we assessed if these parameters were maintained within a pre-defined range, based on the current literature and on local agreement.

RESULTS

The median [first-third Q], range (min-max) number of intraoperative parameters monitored during the 53 gastroschisis surgeries was 6 [5-6], range (4-7). There were no missing data for the automatically recorded ones such as arterial blood pressure, heart rate, end-tidal CO2, and oxygen saturation. Temperature was monitored in 38% of the patients, glycemia in 66%, and natremia in 68% of the cases. Oxygen saturation and heart rate were maintained within the pre-defined range in 96% and 81% of the cases respectively. The blood pressure (28%) and temperature (30%) were instead the least often maintained within the pre-defined range.

CONCLUSION

Although a median of six out of the seven selected intraoperative parameters were monitored during gastroschisis repair, only two of them (oxygen saturation and heart rate) were maintained within the pre-defined range more than 80% of the time. It might be of interest to extend physiologic age- and procedure-based approach to the development of specific preoperative anesthetic planning.

Blood pressure values and hypotension management in extremely preterm infants: a multi-center study

OBJECTIVE

To describe high/low daily blood pressures (BP) and variability in BP management with vasoactive infusions (VI) and/or hydrocortisone (HC) in extremely preterm infants.

STUDY DESIGN

Analysis of data from 24-27 weeks' gestation infants in the Preterm Erythropoietin Neuroprotection (PENUT) Trial. Daily high/low BPs, the use of VI and/or HC, and adverse outcomes were compared descriptively and using regression models.

RESULTS

936 infants were included; 64% untreated, 20% VI, 3% HC, and 13% VI + HC. BP ranges are described for the 602 untreated infants. Considerable inter- and intra-center variability was demonstrated in the rate of VI and/or HC use and the lowest BP on the day of VI or HC initiation.

CONCLUSIONS

Despite published expert opinion guidance regarding BP management in extremely preterm infants, our results suggest a continued lack of consensus result in both inter- and intra-center variability in practice. Well-designed studies in the field are urgently needed.

The effect of norepinephrine on clinical and hemodynamic parameters in neonates with shock: a retrospective cohort study

There is limited data on the cardiovascular effects of norepinephrine (NE) in neonates. Our objective was to describe the clinical responses in neonates treated with NE infusion. This retrospective cohort study included neonates with evidence of shock and those who received NE infusion.

PRIMARY OUTCOME

changes in mean blood pressure (MBP) at 6, 12, and 24 h post-initiation of NE.

SECONDARY OUTCOMES

Changes in (i) diastolic BP, systolic BP, and vasoactive inotrope score (VIS) at 6, 12, and 24 h, (ii) urine output after initiation of NE ii) pH, lactate, fraction of inspired oxygen (FiO2) after initiation of NE, and (iv) adverse outcomes. Fifty infants received NE with mean (SD) gestational age of 34.3 (4.3) weeks and a mean birth weight of 2215 (911) g. Treatment began at a median age of 36 (IQR: 15.2, 67.2) hours of life and lasted 30.5 (IQR: 12.7, 58) hours. MBP improved from 34.4 mm Hg (SD: 6.6) at baseline to 39.4 mm Hg (SD: 10.5, p < 0.001) at 6 h, to 39.6 mm Hg (SD: 12.1, p = 0.002) at 12 h and to 40.4 mm Hg (SD: 15.5, p = 0.004) at 24 h after NE initiation. Vasoactive inotrope score declined from 30 (20, 32) to 10 (4, 30; p < 0.001) at 24 h. Urine output improved within 24 h [1.5 ml/kg/h (0.5, 2.3) at baseline to 3 (1.9, 4.3) at 24 h; p = 0.04]. Oxygen requirement decreased after NE initiation.

CONCLUSION

The use of NE appears to be effective and safe for treating systemic hypotension in neonates.

TRIAL REGISTRATION

Being a retrospective study, trial registration was not considered.

WHAT IS KNOWN

• Dopamine has traditionally been used as the initial agent for treatment of neonatal hypotension. • Norepinephrine has recently been recommended as the first-choice vasopressor agent to correct hypotension in adults and pediatric patients, with insufficient data on the cardiovascular effects of NE in neonates What is new: • Mean blood pressure improved significantly at 6, 12, and 24 h with reduction in vasoactive infusion score at 12 and 24 h after norepinephrine infusion. • No significant change in heart rate or abnormal abdominal adverse effects noted in this study.

Anesthesia protocols for "bedside" preterm patent ductus arteriosus ligation: A single-institutional experience

Background :

Hemodynamically significant patent ductus arteriosus (PDA) is frequently encountered in preterm infants sometimes requiring surgical attention. Although PDA ligation is regularly performed in the operating room, conducting it at the bedside in a neonatal intensive care unit (NICU) and its anesthetic management remains challenging.

Aim :

We aim to discuss the anesthetic considerations in patients undergoing bedside PDA ligation and describe our experience highlighting the feasibility and safety of this procedure.

Setting and Design :

The study was conducted in the NICU in a tertiary care hospital; This was a retrospective, observational study.

Methods :

Preterm infants scheduled for bedside PDA ligation using a predefined anesthesia protocol between August 2005 and October 2020 were included.

Statistical Analysis Used:

Quantitative data were presented as median with interquartile range and categorical data were presented as numbers and percentage thereof.

Results :

Sixty-six premature infants underwent bedside PDA ligation. Thirty-day mortality was 4.5% (3 infants), but there were no procedural deaths. One (1.5%) patient had intraoperative endotracheal tube dislodgement. Three (4.5%) infants had postoperative pneumothorax requiring an additional chest tube insertion. Twenty-one (32%) patients required initiation of postoperative inotrope/vasodilator therapy within 6 h. Three postligation cardiac syndromes (≥ Grade-III mitral regurgitation with left ventricular dysfunction and hypotension) occurred.

Conclusions :

Although anesthesia for preterm neonates undergoing bedside PDA ligation poses unique challenges, it can be safely conducted by following a predetermined standardized anesthesia protocol. Its successful conduct requires utmost vigilance and pristine understanding of the principles of neonatal and cardiac care.

Troponin I Levels in Neonatal Hypoxic-Ischemic Encephalopathy Are Related to Cardiopulmonary Comorbidity and Neurodevelopmental Outcomes

Troponin I is a biomarker for cardiac injury in children. The role of troponin I in neonatal Hypoxic–Ischemic encephalopathy (HIE) may have valuable clinical implications. Troponin I levels were measured within 6 h of birth to determine their relationship to HIE stage, short-term cardiac functional outcomes, and neurodevelopmental outcomes at 1 year. Seventy-three patients were divided into two groups: mild HIE and moderate to severe HIE. Troponin I levels within 6 h of birth were obtained in 61 patients, and were significantly higher in patients with moderate to severe HIE than in patients with mild HIE (Mann–Whitney U test, U = 146, p = 0.001). A troponin I cut-off level of ≥60 pg/mL predicted moderate to severe HIE with a specificity of 81.1% and a negative prediction rate of 76.9%. A troponin I cut-off level of ≥180 pg/mL was significantly (χ² (1, n = 61) = 33.1, p = 0.001, odds ratio 96.8) related with hypotension during first admission and significantly (χ² (1, n = 61) = 5.3, p = 0.021, odds ratio 4.53) related with abnormal neurodevelopmental outcomes at 1 year. Early troponin I level may be a useful biomarker for predicting moderate to severe HIE, and initialization of hypothermia therapy.