Quantitative end-tidal carbon dioxide at initiation of resuscitation may help guide the ventilation of infants born at less than 30 weeks gestation.

AIM: Estimation of end-tidal carbon dioxide (EtCO2 ) with capnography can guide mask ventilation in infants born at less than 30 weeks of gestation. Chemical-sensitive colorimetric devices to detect CO2 are widely used at resuscitation. We aimed to quantify EtCO2 in the first breaths following initiation of mask ventilation at birth and correlated need for endotracheal intubation. METHODS: Infants <30 weeks gestation receiving mask ventilation were randomised into two groups of mask-hold technique (one-person vs. two-person). Data on EtCO2 in the first 30 breaths, time to achieve 5 mmHg, 10 mmHg and 15 mmHg CO2 using a respiratory function monitor was determined. RESULTS: Twenty-five infants with a mean gestation of 27.3 (±3 weeks) and mean birth weight 920.4 (±188.3 g) were analysed. The median EtCO2 was 5.6 mmHg in the first 10 breaths, whereas it was 12.6 mmHg for 11-20 breaths and 18 mmHg for 21-30 breaths. There was no significant difference in maximum median EtCO2 for the first 20 breaths, although EtCO2 was significantly lower in infants who were intubated (32.0 vs. 15.0, p = 0.018). CONCLUSION: EtCO2 monitoring in infants <30 weeks gestation at birth is feasible and reflective of alveolar ventilation. EtCO2 may help guide ventilation of preterm infants at birth.

Cerebral Oxygenation and Perfusion when Positioning Preterm Infants: Clinical Implications.

OBJECTIVES: To evaluate cerebral tissue oxygenation (cTOI) and cerebral perfusion in preterm infants in supine vs prone positions. STUDY DESIGN: Sixty preterm infants, born before 32 weeks of gestation, were enrolled; 30 had bronchopulmonary dysplasia (BPD, defined as the need for respiratory support and/or supplemental oxygen at 36 weeks of postmenstrual age). Cerebral perfusion, cTOI, and polysomnography were measured in both the supine and prone position with the initial position being randomized. Infants with a major intraventricular hemorrhage or major congenital abnormality were excluded. RESULTS: Cerebral perfusion was unaffected by position or BPD status. In the BPD group, the mean cTOI was higher in the prone position compared with the supine position by a difference of 3.27% (P = .03; 95% CI 6.28-0.25) with no difference seen in the no-BPD group. For the BPD group, the burden of cerebral hypoxemia (cumulative time spent with cTOI <55%) was significantly lower in the prone position (23%) compared with the supine position (29%) (P < .001). In those without BPD, position had no effect on cTOI. CONCLUSIONS: In preterm infants with BPD, the prone position improved cerebral oxygenation and reduced cerebral hypoxemia. These findings may have implications for positioning practices. Further research will establish the impact of position on short- and long-term developmental outcomes.

Changes to hepatic tissue oxygenation, abdominal perfusion and its association with enteral feeding with liberal transfusion threshold in anaemic preterm infants: A prospective cohort study.

BACKGROUND AND OBJECTIVES: In anaemic preterm infants who receive packed red blood cell (PRBC) transfusions, changes to mesenteric tissue oxygenation and perfusion have been reported using a restrictive haemoglobin (Hb)-based threshold. We aimed to investigate changes to hepatic tissue oxygenation and abdominal blood flow after PRBC transfusion and its association with enteral feeding using a liberal Hb threshold (as shown inTable1). [Table: see text] MATERIAL AND METHODS: We prospectively studied a cohort of preterm infants born at < 32 weeks' gestation who received at least one PRBC transfusion and monitored them immediately before (Time 1), immediately after (Time 2) and 24 hours after transfusion (Time 3). Data obtained included physiological parameters, the hepatic tissue oxygenation index and pulsed Doppler ultrasound measurements in the abdominal arterial circulation. Additionally, the effects of withholding enteral feeds were investigated. RESULTS: We monitored 50 PRBC transfusion episodes in 40 preterm infants, in whom the mean gestational age was 26.72 weeks (±1.6 weeks) and the mean birth weight was 855.25 g (±190.7 g). We observed significant changes to pulsed Doppler measurements in abdominal arterial circulation (coeliac artery mean peak systolic velocity Time 2 [75.08 cm/sec] versus Time 3 [71.13 cm/sec]; mean end-diastolic velocity Time 2 [15.71 cm/sec] versus Time 3 [13.76 cm/sec]; mean resistive index Time 2 0.78 versus Time 3 0.80, right renal artery mean peak systolic velocity Time 1 58.28 cm/sec versus Time 2 50.97 cm/sec, left renal artery mean peak systolic velocity Time 1 49.20 cm/sec versus Time 2 45.40 cm/sec), but not to hepatic tissue oxygenation after PRBC transfusion (Time 1 mean 53.66 [SD, 13.34]; Time 2 mean 54.93 [SD, 9.3]; Time 3 mean 55.64 [SD, 12.86]). There were no changes to hepatic tissue oxygenation or mesenteric blood flow from withholding enteral feeds during PRBC transfusion. There were no local adverse effects from hepatic tissue oxygenation monitoring. CONCLUSION: In mildly anaemic preterm infants, when allowing a liberal Hb threshold-based trigger for PRBC transfusion, changes in abdominal arterial circulation were present, but not in hepatic tissue oxygenation. Withholding enteral feeds during PRBC transfusion had no impact on hepatic tissue oxygenation or mesenteric flows.

Are there changes to regional tissue oxygenation and circulation following umbilical artery catheter placement? A prospective cohort study in newborn infants.

AIM: The use of umbilical arterial catheters (UACs) is a standard of care in monitoring critically unwell infants. Serious vascular complications are rare but when they do occur, they can be associated with significant morbidity, risking limb loss or even death. Near infra-red spectroscopy has the potential to monitor limb perfusion. Our study investigates changes in tissue oxygenation and perfusion in the abdominal and leg circulation following UAC insertion. METHODS: A prospective observational study performing ultrasound pulsed Doppler measurements in the coeliac, superior mesenteric artery, renal arteries and the femoral arteries as well as near infrared spectroscopy measurements of both thighs at three time points (immediately before = Time 1, 1 h after = Time 2 and 24 h after UAC insertion = Time 3). RESULTS: We monitored 30 infants, the mean gestational age was 30 weeks (24-41) and the mean birthweight was 1720 g (600-4070 g). We observed statistically significant changes (P < 0.05) in pulse Doppler measurements in coeliac (mean peak systolic velocity (PSV): Time 1 = 70.51, Time 2 = 61.75; resistive index (RI): Time 1 = 0.75, Time 2 = 0.67), superior mesenteric (PSV: Time 1 = 41.72, Time 2 = 36.10; RI: Time 1 = 0.92, Time 2 = 0.87), renal (same side end-diastolic velocity: Time 1 = 1.98, Time 2 = 3.80; RI: Time 1 = 0.93, Time 2 = 0.87; opposite side end-diastolic velocity: Time 1 = 2.62, Time 2 = 3.84; RI: Time 1 = 0.92, Time 2 = 0.85) and femoral arteries (same side PSV: Time 1 = 72.75, Time 2 = 62.18; opposite side PSV: Time 1 = 81.89, Time 2 = 62.74). Tissue oxygenation in lower limbs remained unaffected (same side (mean): Time 1 = 68.59, Time 2 = 68.99, Time 3 = 66.40, opposite side: Time 1 = 67.72, Time 2 = 66.92, Time 3 = 65.40). All infants on clinical examination had normal lower limb perfusion, lower limb arterial pulses and normal perfusion to the gluteal region before and after insertion of UAC. CONCLUSIONS: While sub-clinical changes in perfusion occur in abdominal and leg circulation, these changes are not consistent across vessels and regional tissue oxygenation remains unaffected.

Laryngeal mask airway use during neonatal resuscitation: a survey of practice across newborn intensive care units and neonatal retrieval services in Australian New Zealand Neonatal Network.

This is an Australia New Zealand Neonatal Network (ANZNN) wide survey to identify current practice and guide future practice improvement for the use of laryngeal mask airway (LMA) during neonatal resuscitation. An online questionnaire containing 13 questions was sent out to all tertiary neonatal centres (n = 29 units) and neonatal transport units (n = 4) within ANZNN. The non-tertiary (level-II) centres were not included. Response from a senior neonatologist at each centre was received and evaluated. Twenty-two services (67%) had LMA available; of that only, 40% felt the competency of staff to be adequate; and 59% had routine training in LMA use. During neonatal resuscitation, 68% units reported using LMA if endotracheal intubation was unsuccessful after two or more failed intubation attempts and only 18% used it before intubation if face mask ventilation was inadequate. This survey highlighted variations in practice across the tertiary neonatal centres in ANZNN network. One-third of the units lack LMA availability and the units with LMA, face concerns of underutilisation and lack of skills for its use.

Liberal hemoglobin threshold affects cerebral arterial pulsed Doppler and cardiac output, not cerebral tissue oxygenation: a prospective cohort study in anemic preterm infants.

BACKGROUND: Red blood cell (RBC) transfusion is a standard treatment for anemia of prematurity. Cerebral tissue oxygenation and blood flow velocities improve when a restrictive transfusion threshold is followed, but little is known about the effect of practicing a liberal transfusion threshold on cerebral tissue oxygenation, cerebral blood flow velocities, and cardiac output measurements. STUDY DESIGN AND METHODS: A prospective observational study of preterm infants under 32 weeks' gestation who received RBC transfusion. Monitoring was performed immediately before, immediately after, and 24 hours after transfusion. Data obtained included physiologic parameters, cerebral tissue oxygenation index (TOI), anterior and middle cerebral artery pulsed Doppler ultrasound measurements, and cardiac output measurements. Data were analyzed using analysis of variance for repeated measures. RESULTS: Fifty RBC transfusion episodes in 40 preterm infants were monitored. The mean gestational age was 26.72 weeks (±1.6 weeks), and the mean birth weight was 855.25 g (±190.7 g). We did not observe significant changes in cerebral TOI (pretransfusion mean TOI = 70.5 [11.54], immediately after transfusion = 71.38 [12.51], [p = 0.924; 95% confidence interval (CI), -4.64 to 6.39], and 24 hours after transfusion = 75.64 [14.4]; [p = 0.07; 95% CI, -0.37 to 10.65]), cerebral fractional tissue oxygen extraction (pretransfusion = 0.25 [0.12], immediately after transfusion = 0.24 [0.13], and 24 hours after transfusion = 0.20 [0.15]), cerebral resistive index, cerebral pulsatility index, or right ventricular output. Statistically significant changes were observed immediately after transfusion in peak systolic velocity, end-diastolic velocity and time-averaged maximum velocity in the cerebral arterial circulation. Left ventricular output (pretransfusion = 374.32 mL/kg/min, immediately after transfusion = 346.67 mL/kg/min [p = 0.000; 95% CI, -39.61 to -15.68], and 24 hours after transfusion = 361.17 mL/kg/min [p = 0.027; 95% CI, -25.11 to -1.18]) and heart rate (pretransfusion = 163.37 [9.49], immediately after transfusion = 157.29 [10.2] [p = 0.000; 95% CI, -8.96 to -3.20], and 24 hours after transfusion = 160.40 [10.4] [p = 0.041; 95% CI, -5.85 to -0.09]) showed statistically significant changes throughout the monitoring period. CONCLUSION: Our findings show that practicing liberal transfusion thresholds did not improve cerebral TOI in preterm infants who have mild anemia, but it did improve the compensatory response in cerebral arterial blood flow and cardiac output.

The effect of caffeine loading on cerebral autoregulation in preterm infants.

AIM: To evaluate cerebral autoregulation changes in preterm infants receiving a loading dose of caffeine base. METHODS: In a cohort of 30 preterm infants, we extracted measures of cerebral autoregulation using time and frequency domain techniques to determine the correlation between mean arterial pressure (MAP) and tissue oxygenation index (TOI) signals. These measures included the cerebral oximetry index (COx), cross-correlation and coherence measures, and were extracted prior to caffeine loading and in the 2 hours following administration of 10 mg/kg caffeine base. RESULTS: We observed acute reductions in time domain correlation measures, including the cerebral oximetry index (linear mixed model coefficient -0.093, standard error 0.04; p = 0.028) and the detrended cross-correlation coefficient (ρ5 coefficient -0.13, standard error 0.055; p = 0.025). These reductions suggested an acute improvement in cerebral autoregulation. Features from detrended cross-correlation analysis also showed greater discriminative value than other methods in identifying changes prior to and following caffeine administration. CONCLUSION: We observed a reduced correlation between MAP and TOI from near-infrared spectroscopy following caffeine administration. These findings suggest an acute enhanced capacity for cerebral autoregulation following a loading dose of caffeine in preterm infants, contributing to our understanding of the physiological impact of caffeine therapy.

Cardiovascular impact of intravenous caffeine in preterm infants.

AIM: To evaluate the acute effect of intravenous caffeine on heart rate and blood pressure variability in preterm infants. METHODS: We extracted and compared linear and nonlinear features of heart rate and blood pressure variability at two time points: prior to and in the two hours following a loading dose of 10 mg/kg caffeine base. RESULTS: We studied 31 preterm infants with arterial blood pressure data and 25 with electrocardiogram data, and compared extracted features prior to and following caffeine administration. We observed a reduction in both scaling exponents (α1 , α2 ) of mean arterial pressure from detrended fluctuation analysis and an increase in the ratio of short- (SD1) and long-term (SD2) variability from Poincare analysis (SD1/SD2). Heart rate variability analyses showed a reduction in α1 (mean (SD) of 0.92 (0.21) to 0.86 (0.21), p < 0.01), consistent with increased vagal tone. Following caffeine, beat-to-beat pulse pressure variability (SD) also increased (2.1 (0.64) to 2.5 (0.65) mmHg, p < 0.01). CONCLUSION: This study highlights potential elevation in autonomic nervous system responsiveness following caffeine administration reflected in both heart rate and blood pressure systems. The observed increase in pulse pressure variability may have implications for caffeine administration to infants with potentially impaired cerebral autoregulation.

Neopuff T-piece resuscitator mask ventilation: Does mask leak vary with different peak inspiratory pressures in a manikin model?

AIM: The aim of this study was to compare mask leak with three different peak inspiratory pressure (PIP) settings during T-piece resuscitator (TPR; Neopuff) mask ventilation on a neonatal manikin model. METHODS: Participants were neonatal unit staff members. They were instructed to provide mask ventilation with a TPR with three PIP settings (20, 30, 40 cm H2 O) chosen in a random order. Each episode was for 2 min with 2-min rest period. Flow rate and positive end-expiratory pressure (PEEP) were kept constant. Airway pressure, inspiratory and expiratory tidal volumes, mask leak, respiratory rate and inspiratory time were recorded. Repeated measures analysis of variance was used for statistical analysis. RESULTS: A total of 12 749 inflations delivered by 40 participants were analysed. There were no statistically significant differences (P > 0.05) in the mask leak with the three PIP settings. No statistically significant differences were seen in respiratory rate and inspiratory time with the three PIP settings. There was a significant rise in PEEP as the PIP increased. Failure to achieve the desired PIP was observed especially at the higher settings. CONCLUSIONS: In a neonatal manikin model, the mask leak does not vary as a function of the PIP when the flow rate is constant. With a fixed rate and inspiratory time, there seems to be a rise in PEEP with increasing PIP.

Neonatal endotracheal intubation: How to make it more baby friendly.

Neonatal endotracheal intubation is commonly accompanied by significant disturbances in physiological parameters. The procedure is often poorly tolerated, and multiple attempts are commonly required before the airway is secured. Adverse physiological effects include hypoxemia, bradycardia, hypertension, elevation in intracranial pressure and possibly increase in pulmonary vascular resistance. Use of premedications to facilitate intubation has been shown to reduce but not eliminate these effects. Other important preventative factors include adequate training of the operators and guidelines to limit the duration of attempts. Pre-intubation stabilisation with optimal bag and mask ventilation should allow for better neonatal tolerance of the procedure. Recent research has described significant mask leak and airway obstruction compromising efficacy of neonatal mask ventilation. Further research should help in elucidating mask ventilation techniques which minimise mask leak and airway obstruction.

Mask leak increases and minute ventilation decreases when chest compressions are added to bag ventilation in a neonatal manikin model.

AIM: To determine changes in respiratory mechanics when chest compressions are added to mask ventilation, as recommended by the International Liaison Committee on Resuscitation (ILCOR) guidelines for newborn infants. METHODS: Using a Laerdal Advanced Life Support leak-free baby manikin and a 240-mL self-inflating bag, 58 neonatal staff members were randomly paired to provide mask ventilation, followed by mask ventilation with chest compressions with a 1:3 ratio, for two minutes each. A Florian respiratory function monitor was used to measure respiratory mechanics, including mask leak. RESULTS: The addition of chest compressions to mask ventilation led to a significant reduction in inflation rate, from 63.9 to 32.9 breaths per minute (p < 0.0001), mean airway pressure reduced from 7.6 to 4.9 cm H2 O (p < 0.001), minute ventilation reduced from 770 to 451 mL/kg/min (p < 0.0001), and there was a significant increase in paired mask leak of 6.8% (p < 0.0001). CONCLUSION: Adding chest compressions to mask ventilation, in accordance with the ILCOR guidelines, in a manikin model is associated with a significant reduction in delivered ventilation and increase in mask leak. If similar findings occur in human infants needing an escalation in resuscitation, there is a potential risk of either delay in recovery or inadequate response to resuscitation.

Randomised study of a new inline respiratory function monitor (Juno) to improve mask seal and delivered ventilation with neonatal manikins.

BACKGROUND: Respiratory function monitors (RFMs) have been used extensively in manikin and infant studies yet have not become the standard of training. We report the outcomes of a new portable, lightweight RFM, the Juno, designed to show mask leak and deflation tidal volume to assist in positive pressure ventilation (PPV) competency training using manikins. METHODS: Two leak-free manikins (preterm and term) were used. Participants provided PPV to manikins using two randomised devices, self-inflating bag (SIB) and T-piece resuscitator (TPR), with Juno display initially blinded then unblinded in four 90 s paired sequences, aiming for adequate chest wall rise and target minimal mask leak with appropriate target delivered volume when using the monitor. RESULTS: 49 experienced neonatal staff delivered 15 569 inflations to the term manikin and 14 580 inflations to the preterm. Comparing blinded to unblinded RFM display, there were significant reductions in all groups in the number of inflations out of target range volumes (preterm: SIB 22.6-6.6%, TPR 7.1-4.2% and term: SIB 54.8-37.8%, TPR 67.2-63.8%). The percentage of mask leak inflations >60% was reduced in preterm: SIB 20.7-7.2%, TPR 23.4-7.4% and in term: SIB 8.7-3.6%, TPR 23.5-6.2%). CONCLUSIONS: Using the Juno monitor during simulated resuscitation significantly improved mask leak and delivered ventilation among otherwise experienced staff using preterm and term manikins. The Juno is a novel RFM that may assist in teaching and self-assessment of resuscitation PPV technique.

One-person versus two-person mask ventilation in preterm infants at birth: a pilot randomised controlled trial.

BACKGROUND: Mask leak and airway obstruction are common with mask ventilation in newborn infants, leading to suboptimal ventilation. We aimed to perform a pilot study measuring respiratory mechanics during one-person and two-person mask ventilation in preterm infants at birth. METHODS: Infants less than 30 weeks' gestation were eligible for the study. In the two-person method, one person holds the mask in place and the other provides positive pressure ventilation compared with the standard one-person mask hold. A respiratory function monitor was used in line with a T-piece resuscitator to measure mask leak and airway obstruction. Deferred consent was obtained. RESULTS: Twenty-five infants were recruited. The mean (SD) birth weight was 920.4 g (188.3), and mean (SD) gestational age was 27.3 weeks (3.0). Percentage mask leak was higher in the one-person mask method (26.4±18.5) compared with the two-person mask method (17.6±9.3) (p=0.018). The mean (SD) expired tidal volume (VTe, mL) in breaths with leak was 3.9 (1.57) in the one-person method compared with 3.05 (1.0) the two-person method (p=0.31). A significantly lower mean (SD) end-tidal carbon dioxide (EtCO2, mm Hg) was measured at 25.3 (9.9) in breaths with mask leak, compared with 30.8 (12.1) in breaths without leak. The breaths with airway obstruction had lower mean EtCO2 (25.9 vs 30.8, p=0.003) and lower mean VTe (1.71 vs 6.95, p<0.001). CONCLUSION: Mask leak and airway obstruction are common in resuscitation of preterm infants at birth. The use of the two-person mask technique is effective and it could be a useful option if mask ventilation with the one-person method is not effective. TRIAL REGISTRATION NUMBER: ACTRN12614000245695.

Ensemble Approach on Deep and Handcrafted Features for Neonatal Bowel Sound Detection.

For the care of neonatal infants, abdominal auscultation is considered a safe, convenient, and inexpensive method to monitor bowel conditions. With the help of early automated detection of bowel dysfunction, neonatologists could create a diagnosis plan for early intervention. In this article, a novel technique is proposed for automated peristalsis sound detection from neonatal abdominal sound recordings and compared to various other machine learning approaches. It adopts an ensemble approach that utilises handcrafted as well as one and two dimensional deep features obtained from Mel Frequency Cepstral Coefficients (MFCCs). The results are then refined with the help of a hierarchical Hidden Semi-Markov Models (HSMM) strategy. We evaluate our method on abdominal sounds collected from 49 newborn infants admitted to our tertiary Neonatal Intensive Care Unit (NICU). The results of leave-one-patient-out cross validation show that our method provides an accuracy of 95.1% and an Area Under Curve (AUC) of 85.6%, outperforming both the baselines and the recent works significantly. These encouraging results show that our proposed Ensemble-based Deep Learning model is helpful for neonatologists to facilitate tele-health applications.

Comparison of simultaneous auscultation and ultrasound for clinical assessment of bowel peristalsis in neonates.

Introduction: Assessment of bowel health in ill preterm infants is essential to prevent and diagnose early potentially life-threatening intestinal conditions such as necrotizing enterocolitis. Auscultation of bowel sounds helps assess peristalsis and is an essential component of this assessment. Aim: We aim to compare conventional bowel sound auscultation using acoustic recordings from an electronic stethoscope to real-time bowel motility visualized on point-of-care bowel ultrasound (US) in neonates with no known bowel disease. Methods: This is a prospective observational cohort study in neonates on full enteral feeds with no known bowel disease. A 3M™ Littmann® Model 3200 electronic stethoscope was used to obtain a continuous 60-s recording of bowel sounds at a set region over the abdomen, with a concurrent recording of US using a 12l high-frequency Linear probe. The bowel sounds heard by the first investigator using the stethoscope were contemporaneously transferred for a computerized assessment of their electronic waveforms. The second investigator, blinded to the auscultation findings, obtained bowel US images using a 12l Linear US probe. All recordings were analyzed for bowel peristalsis (duration in seconds) by each of the two methods. Results: We recruited 30 neonates (gestational age range 27-43 weeks) on full enteral feeds with no known bowel disease. The detection of bowel peristalsis (duration in seconds) by both methods (acoustic and US) was reported as a percentage of the total recording time for each participant. Comparing the time segments of bowel sound detection by digital stethoscope recording to that of the visual detection of bowel movements in US revealed a median time of peristalsis with US of 58%, compared to 88.3% with acoustic assessment (p < 0.002). The median regression difference was 26.7% [95% confidence interval (CI) 5%-48%], demonstrating no correlation between the two methods. Conclusion: Our study demonstrates disconcordance between the detection of bowel sounds by auscultation and the detection of bowel motility in real time using US in neonates on full enteral feeds and with no known bowel disease. Better innovative methods using artificial intelligence to characterize bowel sounds, integrating acoustic mapping with sonographic detection of bowel peristalsis, will allow us to develop continuous neonatal bowel sound monitoring devices.

Incomplete Exhalation during Resuscitation-Theoretical Review and Examples from Ventilation of Newborn Term Infants.

BACKGROUND: Newborn resuscitation guidelines recommend positive pressure ventilation (PPV) for newborns who do not establish effective spontaneous breathing after birth. T-piece resuscitator systems are commonly used in high-resource settings and can additionally provide positive end-expiratory pressure (PEEP). Short expiratory time, high resistance, rapid dynamic changes in lung compliance and large tidal volumes increase the possibility of incomplete exhalation. Previous publications indicate that this may occur during newborn resuscitation. Our aim was to study examples of incomplete exhalations in term newborn resuscitation and discuss these against the theoretical background. METHODS: Examples of flow and pressure data from respiratory function monitors (RFM) were selected from 129 term newborns who received PPV using a T-piece resuscitator. RFM data were not presented to the user during resuscitation. RESULTS: Examples of incomplete exhalation with higher-than-set PEEP-levels were present in the recordings with visual correlation to factors affecting time needed to complete exhalation. CONCLUSIONS: Incomplete exhalation and the relationship to expiratory time constants have been well described theoretically. We documented examples of incomplete exhalations with increased PEEP-levels during resuscitation of term newborns. We conclude that RFM data from resuscitations can be reviewed for this purpose and that incomplete exhalations should be further explored, as the clinical benefit or risk of harm are not known.

Neonatologist-performed point-of-care abdominal ultrasound: What have we learned so far?

This review describes the sonographic appearances of the neonatal bowel in Necrotising enterocolitis. It compares these findings to those seen in midgut-Volvulus, obstructive intestinal conditions such as milk-curd obstruction, and slow gut motility in preterm infants on continuous positive airway pressure (CPAP)-CPAP belly syndrome. Point-of-care bowel ultrasound is also helpful in ruling out severe and active intestinal conditions, reassuring clinicians when the diagnosis is unclear in a non-specific clinical presentation where NEC cannot be excluded. As NEC is a severe disease, it is often over-diagnosed, mainly due to a lack of reliable biomarkers and clinical presentation similar to sepsis in neonates. Thus, the assessment of the bowel in real-time would allow clinicians to determine the timing of re-initiation of feeds and would also be reassuring based on specific typical bowel characteristics visualised on the ultrasound.

Positive end expiratory pressure and respiratory system resistance between self-inflating bag and T-piece resuscitator in a cadaveric piglet lung model.

Introduction: In neonatal resuscitation, T-piece resuscitator (TPR) are used widely, but the evidence is limited for their use in infants born at term gestation. The aim of this study was to compare the delivered positive end expiratory pressure (PEEP) and respiratory system resistance (Rrs) using TPR and self-inflating bag (SIB) in a cadaveric piglet model. Methods: Cadaveric newborn piglets were tracheotomised, intubated (cuffed tube) and leak tested. Static lung compliance was measured. Positive pressure ventilation was applied by TPR and SIB in a randomized sequence with varying, inflations per minute (40, 60 and 80 min) and peak inspiratory pressures (18 and 30 cmH2O). PEEP was constant at 5 cmH2O. The lungs were washed with saline and static lung compliance was re-measured; ventilation sequences were repeated. Lung inflation data for the respiratory mechanics were measured using a respiratory function monitor and digitally recorded for both pre and post-lung wash inflation sequences. A paired sample t-test was used to compare the mean and standard deviation. Results: The mean difference in PEEP (TPR vs. SIB) was statistically significant at higher inflation rates of 60 and 80 bpm. At normal lung compliance, mean difference was 1.231 (p = 0.000) and 2.099 (p = 0.000) with PIP of 18 and 30 cmH2O respectively. Significantly higher Rrs were observed when using a TPR with higher inflation rates of 60 and 80 bpm at varying lung compliance. Conclusion: TPR is associated with significantly higher PEEP in a compliant lung model, which is probably related to the resistance of the TPR circuit. The effect of inadvertent PEEP on lung mechanics and hemodynamics need to be examined in humans. Further studies are needed to assess devices used to provide PEEP (TPR, SIB with PEEP valve, Anaesthetic bag with flow valve) during resuscitation of the newborn.

Newborn resuscitation devices: The known unknowns and the unknown unknowns.

Infant resuscitation devices used at birth must be capable of delivering adequate and consistent ventilation in a controlled and predictable manner to a wide patient weight range, and combinations of transitional lung states. Manual inflation resuscitation devices delivering positive pressure lung inflation at birth can be classified broadly into two types: 1) flow generating, ie silicone self-inflating bags (SIB) also known as bag valve mask (BVM) and 2) flow dependent, ie anaesthetic flow inflating bag (FIB) and t-piece resuscitator (TPR) systems (eg: Neopuff, GE Panda and Draeger Resuscitaires). Globalization, lower production costs, and an expanding market need for devices, has led to a proliferation of brands (both reusable and single use) within a class type. T-piece resuscitators have become the dominant device particularly in high income countries. There remains a paucity of information on the performance characteristics of these devices and their ability to provide the required respiratory parameters for effective and safe ventilation across the full-expected weight range and lung states to which they will be applied. This review aims to inform current clinical practise on the biomechanical efficiency, reliability and efficacy of the most common devices used to apply PPV to newborns and infants ≤10 kgs.

Neonatal Resuscitation With T-Piece Systems: Risk of Inadvertent PEEP Related to Mechanical Properties.

Background: Resuscitation of infants using T-piece resuscitators (TPR) allow positive pressure ventilation with positive end-expiratory pressure (PEEP). The adjustable PEEP valve adds resistance to expiration and could contribute to inadvertent PEEP. The study indirectly investigated risk of inadvertent peep by determining expiratory time constants. The aim was to measure system expiratory time constants for a TPR device in a passive mechanical model with infant lung properties. Methods: We used adiabatic bottles to generate four levels of compliance (0.5-3.4 mL/cm H2O). Expiratory time constants were recorded for combinations of fresh gas flow (8, 10, 15 L/min), PEEP (5, 8, 10 cm H2O), airway resistance (50, 200 cm H2O/L/sec and none), endotracheal tube (none, size 2.5, 3.0, 3.5) with a peak inflation pressure of 15 cm H2O above PEEP. Results: Low compliances resulted in time constants below 0.17 s contrasting to higher compliances where the expiratory time constants were 0.25-0.81 s. Time constants increased with increased resistance, lower fresh gas flows, higher set PEEP levels and with an added airway resistance or endotracheal tube. Conclusions: The risk of inadvertent PEEP increases with a shorter time for expiration in combination with a higher compliance or resistance. The TPR resistance can be reduced by increasing the fresh gas flow or reducing PEEP. The expiratory time constants indicate that this may be clinically important. The risk of inadvertent PEEP would be highest in intubated term infants with highly compliant lungs. These results are useful for interpreting clinical events and recordings.