Neonatal echocardiography

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.

Implementing a successful targeted neonatal echocardiography service and a training program: The ten stages of change

Implementing any new service or program in the health care system is not always straightforward; a multi-stage implementation process is required most of the time. With the advancements in neonatal care and increased survival rates, there has been an increased need for ongoing assessment of hemodynamic stability. At the Children's Hospital of Eastern Ontario and the Ottawa Hospital Neonatal Intensive Care Units (NICUs), University of Ottawa, Canada, Targeted Neonatal Echocardiography service (TnEcho) was successfully established and has led to improvement in the hemodynamic evaluation and decision making in neonatal intensive care. In this article, we describe our experience establishing this program and the process of ensuring its success. This review article highlights the ten steps taken by multiple stakeholders to achieve this goal; this may help other centres implement a similar program.

Respiratory distress syndrome: influence of management on the hemodynamic status of ≤ 32-week preterm infants in the first 24 hours of life

Objective

To investigate the influence of respiratory distress syndrome management on clinical and echocardiographic parameters used for hemodynamic evaluation in ≤ 32- week newborns.

Methods

Thirty-three ≤ 32-week newborns were prospectively evaluated and subjected to invasive mechanical ventilation. The need for exogenous surfactant and clinical and echocardiographic parameters in the first 24 hours of life was detailed in this group of patients.

Results

The mean airway pressure was significantly higher in newborn infants who required inotropes [10.8 (8.8 - 23) cmH₂O versus 9 (6.2 - 12) cmH₂O; p = 0.04]. A negative correlation was found between the mean airway pressure and velocity-time integral of the pulmonary artery (r = -0.39; p = 0.026), right ventricular output (r = -0.43; p = 0.017) and measurements of the tricuspid annular plane excursion (r = -0.37; p = 0.036). A negative correlation was found between the number of doses of exogenous surfactant and the right ventricular output (r = -0.39; p = 0.028) and pulmonary artery velocity-time integral (r = -0.35; p = 0.043).

Conclusion

In ≤ 32-week newborns under invasive mechanical ventilation, increases in the mean airway pressure and number of surfactant doses are correlated with the worsening of early cardiac function. Therefore, more aggressive management of respiratory distress syndrome may contribute to the hemodynamic instability of these patients.

Rapid Assessment of the Neonate With Sonography (RANS) Scan

The use of point-of-care sonography in clinical settings such as emergency medicine and intensive care units has increased, but adoption in neonatology has been slow. Unlike the focused assessment with sonography for trauma scan used in adults, a quick bedside scan to rapidly evaluate an acutely deteriorating neonate does not exist. The objective of our article is to introduce a focused bedside ultrasound scan that is easy to learn, rapidly performed, and relatively inexpensive.© 2018 by the American Institute of Ultrasound in Medicine.

Understanding the Pathophysiology, Implications, and Treatment Options of Patent Ductus Arteriosus in the Neonatal Population

BACKGROUND

Patent ductus arteriosus (PDA) is the persistence of a fetal shunt between the pulmonary artery and the aorta. This structure normally closes in the first 3 days after birth; however, closure is delayed in up to 80% of infants born at 25 to 28 weeks of gestation. Persistent PDA results in pulmonary overcirculation and systemic hypoperfusion.

PURPOSE

The purpose of this article is to review pathophysiology and treatment options for PDA.

METHODS

A literature review was conducted using PubMed, CINAHL, and Google Scholar (2013-2018). Search terms included neonate, PDA, pathophysiology, pharmacotherapy, nursing, ligation, indomethacin, ibuprofen, and acetaminophen (paracetamol).

RESULTS

Optimal treatment remains contentious. Options include conservative/medical, pharmacologic, and surgical management. Conservative/medical management includes mild fluid restriction, increased airway pressures, and supportive care. Pharmacologic treatment is accomplished using indomethacin, ibuprofen, or acetaminophen. Surgical intervention is by direct closure or by percutaneous ligation. Treatment may be prophylactic, presymptomatic, or symptomatic. Long-term morbidities associated with PDA include chronic lung disease, retinopathy of prematurity, and neurodevelopmental delay.

IMPLICATIONS FOR RESEARCH

Absence of a universal scoring system for severity of PDA limits accuracy of comparisons among research studies. Lack of a consistent definition also makes it difficult to aggregate data for meta-analyses. Adoption of a consistent scoring system for hemodynamic significance would facilitate comparisons of outcomes among research studies.

IMPLICATIONS FOR PRACTICE

Clinicians should be aware of treatment options for PDA and their implications on neonatal outcomes. For nurses, anticipation of possible side effects is important for performance of focused assessments.

The role of Neonatologist Performed Echocardiography in the assessment and management of neonatal shock

One of the major challenges of neonatal intensive care is the early detection and management of circulatory failure. Routine clinical assessment of the hemodynamic status of newborn infants is subjective and inaccurate, emphasizing the need for objective monitoring tools. An overview will be provided about the use of neonatologist-performed echocardiography (NPE) to assess cardiovascular compromise and guide hemodynamic management. Different techniques of central blood flow measurement, such as left and right ventricular output, superior vena cava flow, and descending aortic flow are reviewed focusing on methodology, validation, and available reference values. Recommendations are provided for individualized hemodynamic management guided by NPE.

The state of point-of-care ultrasonography use and training in neonatal-perinatal medicine and pediatric critical care medicine fellowship programs

OBJECTIVE

The current state of point-of-care ultrasonography (POCUS) use and education in neonatal-perinatal medicine (NPM) and pediatric critical care medicine (PCCM) is unknown. Our aim was to quantify POCUS use, training and perceptions regarding education and barriers among the United States NPM and PCCM fellowship programs.

STUDY DESIGN

A 14-question survey was emailed to the fellowship directors of all the United States NPM and PCCM fellowship programs.

RESULTS

The response rate was 55% (52/95) and 59% (39/66) for NPM and PCCM programs, respectively. Over 90% of respondents in both groups believe that fellows and attendings should receive POCUS training. PCCM programs, compared with NPM, had greater access to POCUS machines (97% vs 63%, P<0.001), and more often used POCUS for diagnoses and management (76% vs 29%, P<0.001) and procedural guidance (95% vs 37%, P<0.001). The most common indications were cardiac/hemodynamics, pulmonary pathology and vascular access in both specialties. PCCM reported more training to fellows (90% vs 29%, P<0.001). Both group perceived lack of time to learn, lack of equipment/funds, liability concerns, lack of personnel to train physicians and cardiology/radiology resistance as significant barriers to POCUS implementation.

CONCLUSIONS

Both NPM and PCCM fellowship programs believe in the benefits of POCUS and that their physicians should receive the necessary training. Compared with PCCM, NPM fellowships programs have less access to POCUS machines and less frequently use POCUS and train their fellows and attendings. There remain significant barriers to utilization of POCUS, especially in NPM.