Assessment of the reliability and validity of a novel point-of-care fibrinogen (F-Point) device against an industry standard at fibrinogen levels >2 g/L in non-haemorrhage scenarios

INTRODUCTION

A diagnostic accuracy study assessing the reliability and validity of a novel plasma fibrinogen point-of-care (F-Point) device compared with the von Clauss method of assay.

METHODS

Forty-one women presenting for elective caesarean delivery and 43 non-pregnant female patients presenting for elective gynaecological surgery were recruited to assess agreement at normal fibrinogen levels (elective gynaecological cohort) and high fibrinogen levels (elective caesarean section cohort). Validity was assessed by comparing the F-Point results with the gold standard of von Clauss fibrinogen assay performed on the ACL Top 500. Reliability (test-retest) and validity were assessed using the intraclass correlation to control for operator variance (two-way random absolute agreement method), presented as intra class correlation coefficients (ICCs) and 95% confidence interval, and Bland-Altman analysis, presented as mean bias and 95% limits of agreement and coefficient of variation (COV).

RESULTS

The results demonstrated a high test-retest reliability demonstrated in the paired F-Point measurements with an intraclass correlation coefficient (ICC) of 0.95, a bias of 0 (-00.69 to 0.69) and a COV of 9%. Similarly, there was acceptable agreement demonstrated between F-Point and von Clauss assay with an ICC of 0.91, a bias of -0.1 (-0.96 to 0.75) and a COV of 11%.

CONCLUSIONS

Our novel plasma fibrinogen point-of-care device has been shown to be reliable and valid when testing fibrinogen levels as low as 2 g/L. Future studies investigating the correlation at lower fibrinogen levels, for example during haemorrhage and in patients with coagulopathies, are required.

Staff Attitudes towards Patient Safety Culture and Working Conditions in an Irish Tertiary Neonatal Unit

Introduction There is little published research evaluating attitudes towards patient safety culture and working conditions in neonatal units. This study aimed to explore this within a Level III Irish neonatal unit setting. Methods This was a quantitative, cross-sectional study performed in the Rotunda Hospital, Dublin. A 30-item safety attitudes questionnaire (SAQ) was utilized to analyze staff perceptions in areas including job satisfaction, working conditions and stress recognition. Results The ‘Stress Recognition’ domain received the highest score (75.3) followed by ‘Job Satisfaction’ domain with a mean score of 74.4. The lowest mean scale score in the neonatal unit was for ‘Perceptions of Management’, with a mean score of 50.7. Collaboration and Communication scores were high across all disciplines. Conclusion This SAQ has highlighted a number of important areas for quality improvement and staff satisfaction in our neonatal unit.

The utility of routine echocardiography in newborn infants with a persistent oxygen requirement

In the era of antenatal screening for congenital heart disease (CHD), infants presenting with an undiagnosed significant CHD are rare. However, term infants admitted with an initial diagnosis of TTN and a prolonged oxygen requirement often undergo an echocardiogram. We aimed to assess whether this practice yields any additional cases of undiagnosed CHD. We performed a retrospective chart review over a three year period [2013 – 2015] of term (> 36 weeks) infants admitted to the NICU for ≥ 5 days with a diagnosis of TTN and received an echocardiogram. The presence of CHD on the echocardiogram was assessed. Forty-seven infants were enrolled. The median age of echocardiogram was day four [2 – 8]. No infant had a diagnosis of significant CHD on the postnatal echocardiogram. A small muscular VSD was identified in two infants. Routine echocardiography for this cohort of infants to rule out major CHD appears to be unwarranted.

The effect of antenatal magnesium sulfate on left ventricular afterload and myocardial function measured using deformation and rotational mechanics imaging

OBJECTIVE

Assess the effect of antenatal magnesium sulfate (MgSO4) on left ventricular function measured using deformation and rotational mechanics imaging.

STUDY DESIGN

Infants who received MgSO4 were matched for gestation, birth weight and mode of delivery with controls. Echocardiography was carried out on days 1 and 2 to measure left ventricle longitudinal strain (LV LS), twist, untwist rate, ejection fraction (EF), and systemic vascular resistance (SVR).

RESULTS

Thirty-eight infants with a median gestation and birth weight of 27.1 weeks and 923 g were included. On day 1, the MgSO4 group (n=19) had a lower SVR and higher LV LS, EF, twist and untwist rate than the Control group (n=19) (all P<0.05). There were no differences between the groups on day 2.

CONCLUSION

Antenatal MgSO4 administration is associated with a lower SVR and higher myocardial function on day 1 in preterm infants <29 weeks gestation.

The Use of Inhaled Nitric Oxide in a Tertiary Neonatal Intensive Care Unit

There is currently insufficient evidence to create a standardised protocol for the use and weaning of inhaled nitric oxide (iNO). We aimed to determine our application of iNO in this patient cohort. We performed a retrospective chart review on patients receiving iNO therapy for persistent pulmonary hypertension of the newborn (PPHN) from a single tertiary neonatal centre in 2014. The data was entered into the European Inhaled Nitric Oxide Registry. Thirty two babies were treated with iNO during this period, 9 of which were less than 32 weeks gestation. The median time to initiation of iNO treatment was 4-5 hours and the median duration of treatment was 74 hours for term and 66 hours for preterm infants. We recommend that further use of the European Inhaled Nitric Oxide Registry across more neonatal units in the Republic of Ireland could lead to the development of national guidelines on iNO use and weaning in this cohort.

Using lateral radiographs to determine umbilical venous catheter tip position in neonates

We aimed to assess the difference in measurement of the distance of the UVC tip from the diaphragm between (Anteroposterior) AP and lateral radiographs and to determine the reliability of the measurement of UVC tip distance from the diaphragm between the two views. A retrospective review of paired AP and lateral radiographs taken to assess UVC tip position was carried out in 25 infants was conducted and reliability analysis was carried out. There was a significant difference in the mean (SD) distance of the UVC catheter above the diaphragm between the AP and lateral radiographs: 8.7 (7.8) mm versus 11.6 (7.3) mm (p = 0.003) respectively. Measurements using lateral radiographs were more reliable (Intraclass correlation coefficient: 0.99 vs. 0.93). Inter-observer reliability analysis yielded similar results. Lateral radiographs are more reliable in measurement of UVC tip position and should be performed in conjunction with AP films to aid in determining UVC position.

Evaluation of cerebral electrical activity and cardiac output after patent ductus arteriosus ligation in preterm infants

OBJECTIVE

To characterize and investigate the relationship between systemic blood flow and pre- and postoperative cerebral electrical activity in preterm neonates undergoing patent ductus arteriosus (PDA) ligation.

STUDY DESIGN

A prospective observational study was conducted in 17 preterm neonates undergoing PDA ligation. All infants had amplitude-integrated electroencephalography (aEEG) recorded continuously from 4 h preoperatively to 24 h postoperatively. Targeted neonatal echocardiography was performed to evaluate myocardial performance and systemic blood flow at four sequential time points: preoperatively; 1, 8 and 24 h postoperatively.

RESULT

PDA ligation was followed by a fall in the lower border of the aEEG trace lower left ventricular output, but recovery of diastolic flow in the middle cerebral artery. Altered lower margin was associated with gestational age and PDA diameter on univariate analysis, but not with low cardiac output.

CONCLUSION

PDA ligation was associated with altered cerebral electrical activity, although these changes were not related to low cardiac output state.

Myocardial assessment using tissue doppler imaging in preterm very low-birth weight infants before and after red blood cell transfusion

OBJECTIVE

To investigate myocardial velocities in anemic very low-birth weight (VLBW) preterm infants, pre and post red blood cells transfusion using tissue Doppler imaging echocardiography.

STUDY DESIGN

Forty-eight VLBW preterm infants34 weeks and>2 weeks old were prospectively divided: Transfused symptomatic infants (Hematocrit (Hct)<0.30 (n=32)) and non transfused asymptomatic controls (control 1, Hct >0.30 (n=9) and control 2, Hct <0.30 (n=7)). Echocardiography was performed before and 3-5 days after transfusion in the transfused, and the controls were studied at similar intervals. Non parametric tests were used for statistical analysis.

RESULT

Left ventricular (LV) systolic velocity increased (transfused (4.6±0.70 vs 6.0±0.65, P<0.01)) as did LV diastolic velocities (P<0.01) without significant difference over time in each control. The percentage change in LV velocity following transfusion correlated negatively (ρ=0.36) with pre transfusion Hct.

CONCLUSION

There is a significant increase in myocardial performance following transfusion, which is related to the severity of the anemia.

Neonatal respiratory extracorporeal membrane oxygenation (ECMO) referrals

Extracorporeal membrane oxygenation (ECMO) is a complex technique for providing life support in neonatal respiratory failure. T UK Collaborative ECMO trial demonstrated cost-effectiveness and substantial improvements in neurological morbidity and mortality. Currently, infants requiring ECMO in Ireland are referred to one of various centres in the UK and Scandinavia. We aimed to review the number of infants referred from Ireland for respiratory ECMO. All infants with a non-cardiac condition referred from Ireland for ECMO were reviewed for diagnosis and outcomes. Eleven infants required ECMO between June 2006 and January 2009 and were referred to the Scandinavian team for ECMO transport although one infant improved and did not require ECMO following the arrival of the team. Four infants died: one infant died prior to arrival of the ECMO team, 3 infants had fatal diagnoses and one infant with congenital diaphragmatic hernia received pre-op ECMO. The median (inter-quartile range) gestational age was 39.7 (38.3-40.7) weeks and birth weight of 3.7 (3.2-4.0) kg. The median age at the decision to transfer for ECMO was 13h (4-123) and the team arrived at 23 h (12-132). All infants had a normal cranial ultrasound and echo prior to ECMO and 2 infants had an abnormal MRI post-ECMO. The time on ECMO was 9 days (3-17) and total length of hospital stay was 32 d (23-36). There were no pre-ECMO clinical or biochemical

Elevated iron indices in preterm infants: association with male gender

Elevated iron indices may be underrecognized in preterm infants. Sixty growing, stable preterm infants < 1500 g studied had elevated iron indices, which was especially elevated in male infants. Careful evaluation of iron indices is essential to prevent potential organ injury and unnecessary iron supplementation.

Biochemical markers may identify preterm infants with a patent ductus arteriosus at high risk of death or severe intraventricular haemorrhage

BACKGROUND

A patent ductus arteriosus (PDA) in preterm infants is associated with increased risk of intraventricular haemorrhage (IVH) and death. Cardiac troponin T (cTnT) and N-terminal-pro-B type natriuretic peptide (NTpBNP) are markers of cardiac function and can predict poor outcome in adults.

AIMS

To determine whether echocardiography and cTnT/NTpBNP levels at 48 h predict death before discharge or severe IVH in preterm infants with a PDA.

METHODS

Infants born <32 weeks' gestation or <1500 g underwent echocardiographic and cTnT/NTpBNP measurements at 12 and 48 h of life. Infants were divided according to their status at discharge: a closed PDA at 48 h, infants with a PDA at 48 h and IVH III/IV and/or death, and infants with a PDA at 48 h without IVH III/IV or death.

RESULTS

Eighty infants with a median gestation of 28 weeks (IQR 26.1-29.5) and birth weight 1.06 kg (0.8-1.21) were included. At 48 h, infants with a PDA and IVH III/IV and/or death had significantly higher median cTnT/NTpBNP levels compared to infants with a PDA without IVH III/IV and/or death and those with spontaneous PDA closure (NTpBNP 9282, 5121 and 740 pmol/l, respectively, p = 0.008, and cTnT 0.66, 0.25 and 0.13 microg/l, respectively, p = 0.027). There were no differences in echocardiographic parameters of PDA size, left atrial to aortic ratio (LA:Ao), left and right ventricular outputs between the PDA groups.

CONCLUSIONS

NTpBNP and cTnT in conjunction with echocardiography may provide a basis for trials of targeted medical treatment in infants with a PDA.

Serum albumin and mortality in very low birth weight infants

Serum albumin is a predictor of outcome in adults but its role in paediatric patients is unclear. Earliest albumin was not associated with mortality or morbidity in very low birth weight (VLBW) infants. However, the lowest serum albumin had a statistically significant inverse correlation with mortality and potentially plays a prognostic role in VLBW neonates.

Patent ductus arteriosus evaluation by serial echocardiography in preterm infants

BACKGROUND

Patent ductus arteriosus (PDA) is associated with morbidity and mortality in premature neonates.

METHODS

The effect of serial echocardiography performed by a neonatologist and early targeted medical PDA treatment was evaluated and compared to historical controls. One hundred ninety-two infants <1,500 g were included and 45 infants had a PDA.

RESULTS

Serial echocardiography allowed significantly earlier identification and treatment of PDA versus awaiting the evolution of clinical signs. Severe intraventricular haemorrhage and ventilator days were significantly decreased in the studied cohort following the introduction of echocardiography. In addition, hospital stay was also reduced in the non-PDA group and other outcomes were unchanged.

CONCLUSION

Serial echocardiography for PDA evaluation, performed by a neonatologist trained in echo, may reduce morbidity in preterm infant.

Efficacy of intravenous immunoglobulin in the management of haemolytic disease of the newborn

Intravenous immunoglobulin (IVIG) is indicated for use in Rhesus and ABO hemolytic disease of the newborn (HDN) to reduce the need for exchange transfusion, to decrease hospital stay and the duration of phototherapy. 11 infants received IVIG and the effect of IVIG on the total serum bilirubin (TSB) level, and its effect on the rate of rise of TSB was quantified. There was a statistically significant decrease in bilirubin levels before and after treatment with IVIG from 234 to 219 micromol/L (p = 0.001). In addition, the rate of change in bilirubin level significantly altered from an upward to a downward trend. (p = 0.001). The Number Needed to Treat (NNT) to prevent an exchange transfusion was 2.75--comparable with the recent systematic review of IVIG with a NNT of 2.7.