A multi-centre randomised controlled trial of respiratory function monitoring during stabilisation of very preterm infants at birth.

AIM: To determine whether the use of a respiratory function monitor (RFM) during PPV of extremely preterm infants at birth, compared with no RFM, leads to an increase in percentage of inflations with an expiratory tidal volume (Vte) within a predefined target range. METHODS: Unmasked, randomised clinical trial conducted October 2013 - May 2019 in 7 neonatal intensive care units in 6 countries. Very preterm infants (24-27 weeks of gestation) receiving PPV at birth were randomised to have a RFM screen visible or not. The primary outcome was the median proportion of inflations during manual PPV (face mask or intubated) within the target range (Vte 4-8 mL/kg). There were 42 other prespecified monitor measurements and clinical outcomes. RESULTS: Among 288 infants randomised (median (IQR) gestational age 26+2 (25+3-27+1) weeks), a total number of 51,352 inflations were analysed. The median (IQR) percentage of inflations within the target range in the RFM visible group was 30.0 (18.0-42.2)% vs 30.2 (14.8-43.1)% in the RFM non-visible group (p = 0.721). There were no differences in other respiratory function measurements, oxygen saturation, heart rate or FiO2. There were no differences in clinical outcomes, except for the incidence of intraventricular haemorrhage (all grades) and/or cystic periventricular leukomalacia (visible RFM: 26.7% vs non-visible RFM: 39.0%; RR 0.71 (0.68-0.97); p = 0.028). CONCLUSION: In very preterm infants receiving PPV at birth, the use of a RFM, compared to no RFM as guidance for tidal volume delivery, did not increase the percentage of inflations in a predefined target range. TRIAL REGISTRATION: Dutch Trial Register NTR4104, clinicaltrials.gov NCT03256578.

Neonatal Safety of Elective Family-Centered Caesarean Sections: A Cohort Study.

BACKGROUND: Although little data are available concerning safety for newborns, family-centered caesarean sections (FCS) are increasingly implemented. With FCS mothers can see the delivery of their baby, followed by direct skin-to-skin contact. We evaluated the safety for newborns born with FCS in the Leiden University Medical Center (LUMC), where FCS was implemented in June 2014 for singleton pregnancies with a gestational age (GA) ≥38 weeks and without increased risks for respiratory morbidity. METHODS: The incidence of respiratory pathology, unplanned admission, and hypothermia in infants born after FCS in LUMC were retrospectively reviewed and compared with a historical cohort of standard elective cesarean sections (CS). RESULTS: From June 2014 to November 2015, 92 FCS were performed and compared to 71 standard CS in 2013. Incidence of respiratory morbidity, hypothermia, temperatures at arrival at the department, GA, and birth weight were comparable (ns). Unplanned admission occurred more often after FCS when compared to standard CS (21 vs 7%; p = 0.03), probably due to peripheral oxygen saturation (SpO2) monitoring. There was no increase in respiratory pathology (8 vs 6%, ns). One-third of the babies were separated from their mother during or after FCS. CONCLUSION: Unplanned neonatal admissions after elective CS increased after implementing FCS, without an increase in respiratory morbidity or hypothermia. SpO2 monitoring might have a contribution. Separation from the mother occurred often.

The Breathing Effort of Very Preterm Infants at Birth.

OBJECTIVE: To compare the respiratory effort of very preterm infants receiving positive pressure ventilation (PPV) with infants breathing on continuous positive airway pressure (CPAP), directly after birth. STUDY DESIGN: Recorded resuscitations of very preterm infants receiving PPV or CPAP after birth were analyzed retrospectively. The respiratory effort (minute volume and recruitment breaths [>8 mL/kg], heart rate, oxygen saturation, and oxygen requirement were analyzed for the first 2 minutes and in the fifth minute after birth. RESULTS: Respiratory effort was analyzed in 118 infants, 87 infants receiving PPV and 31 infants receiving CPAP (median gestational age, 28 weeks [IQR, 26-29] vs 29 weeks [IQR, 29-30; P < .001); birth weight, 1059 g [IQR, 795-1300] vs 1205 g [IQR, 956-1418; P = .06]). The minute volume of spontaneous breaths of infants receiving PPV was lower at 2 minutes (37 mL/kg/minute [IQR, 15-69] vs 188 mL/kg/minute [IQR, 128-297; P < .001]) and at 5 minutes (112 mL/kg/minute [IQR, 46-229] vs 205 mL/kg/minute [IQR, 174-327; P < .001]). Recruitment breaths occurred less in the PPV group at 2 minutes (0 breaths/minute [IQR, 0-1] vs 4 breaths/minute [IQR, 1-8; P < .001]) and 5 minutes (0 breaths/minute [IQR, 0-3] vs 2 breaths/minute [IQR, 0-11; P = .01). The heart rate was lower in the PPV group (94 beats/minute [IQR, 68-128] vs 124 beats/minute [IQR, 100-144; P = .02]) as was oxygen saturation (50% [IQR, 35%-66%] vs 67% [IQR, 34%-80%; P = .04]), but not different at 5 minutes (heart rate, 149 beats/minute [IQR, 131-162] vs 150 beats/minute [IQR, 132-160; P = NS]; oxygen saturation , 91% [IQR, 80%-95%] vs 92% [IQR, 89%-97%; P = NS]). The oxygen requirement was higher (at 2 minutes, 30% [IQR, 21%-53%] vs 21% [IQR, 21%-29%; P = .05]; at 5 minutes, 39% [IQR, 22%-91%] vs 22% [IQR, 21%-31%; P = .003]). CONCLUSION: Very preterm infants breathe at birth when receiving PPV, but the respiratory effort was significantly lower when compared with infants receiving CPAP only. The reduced breathing effort observed likely justified applying PPV in most infants.

The effect of breathing on ductus arteriosus blood flow directly after birth.

Spontaneous breathing at birth influences ductus arteriosus (DA) flow. This study quantifies the effect of breathing on DA shunting directly after birth. In healthy term infants born by elective cesarean section, simultaneous measurements of DA shunting and tidal volumes during spontaneous breathing were performed at 2-5, 5-8, and 10-13 min after birth. Eight infants with a mean (SD) gestational age of 40 (1) weeks and 3216 (616) grams were studied. Inspiratory tidal volume was 5.8 (3.3-7.7), 5.7 (4.0-7.1), and 5.2 (4.3-6.1) mL/kg at 2-5, 5-8, and 10-13 min. The velocity time integral of left-to-right shunting significantly increased during inspiration when compared to expiration (8.4 (5.2) vs. 3.7 (2.3) cm, 8.9 (4.4) vs. 5.6 (3.4) cm, and 14.0 (6.7) vs. 8.4 (6.9) cm; all p < 0.0001) at 2-5, 5-8, and 10-13 min, respectively. In contrast, right-to-left shunting was not different between inspiration and expiration at 2-5 and 10-13 min (11.1 (2.4) vs. 11.1 (2.6) cm and 10.7 (2.3) vs. 10.6 (3.0) cm; p > 0.05), but there was a small increase at 5-8 min (12.1 (2.4) vs. 10.8 (2.9) cm; p = 0.001) during expiration. CONCLUSION: Directly after birth, ductal shunting is influenced by breathing effort, predominantly with an increase in left-to-right shunt due to inspiration. What is Known: • Spontaneous breathing at birth influences ductus arteriosus flow and pulmonary blood flow. • Crying causes a significant increase in left-to-right ductus arteriosus shunting. What is New: • Left-to-right ductus arteriosus shunting increases during inspiration compared to expiration. • Breathing is important for ductal shunting and contributes to pulmonary blood flow.

Herpes simplex transmission to chest and face through autoinoculation in an infant.

A 4-month-old female infant presented with a vesicular lesion on her left hand present since 1 day. A few days prior to presentation, she had a similar lesion on the lower lip. Two days after presentation, she returned with new lesions on her thorax and upper eyelid. PCR of the vesicle was positive for herpes simplex virus type 1. The transmission to her chest and face probably resulted from autoinoculation, caused by rubbing of the hand on other parts of the body. Transmission of herpes simplex through skin-to-skin contact is a common route of infection in people engaging in contact sports. Antiviral therapy was started because of the extensiveness and expansion of lesions and risk of developing herpetic keratitis. The patient completely recovered. This case shows that in an otherwise healthy infant, multiple herpetic skin lesions were not due to disseminated infection, but through autoinoculation.

Caffeine to improve breathing effort of preterm infants at birth: a randomized controlled trial.

BackgroundCaffeine promotes spontaneous breathing by antagonizing adenosine. We assessed the direct effect of caffeine on respiratory effort in preterm infants at birth.MethodsThirty infants of 24-30 weeks of gestation were randomized for receiving caffeine directly after birth in the delivery room (caffeine DR group) or later in the neonatal intensive care unit (control group). Primary outcome was respiratory effort, expressed as minute volume, tidal volumes, respiratory rate, rate of rise to maximum tidal volume, and recruitment breaths at 7-9 min after birth.ResultsAfter correction for gestational age, minute volumes ((mean±SD; 189±74 vs. 162±70 ml/kg/min; P<0.05) and tidal volumes ((median (interquartile range (IQR)) 5.2 (3.9-6.4) vs. 4.4 (3.0-5.6) ml/kg) were significantly greater in the caffeine DR group. Although respiratory rates were similar ((mean±SD) 35±10 vs. 33±10), RoR increased significantly ((median (IQR) 14.3 (11.2-19.8) vs. 11.2 (7.9-15.2) ml/kg/s), and more recruitment breaths were observed (13 vs. 9%).ConclusionCaffeine increases respiratory effort in preterm infants at birth, but the effect on clinical outcomes needs further investigation.

Accuracy of currently available neonatal respiratory function monitors for neonatal resuscitation.

UNLABELLED: This study aimed to test the accuracy in volume measurements of three available respiratory function monitors (RFMs) for neonatal resuscitation and the effect of changing gas conditions. The Florian, New Life Box Neo-RSD (NLB Neo-RSD) and NICO RFM were tested on accuracy with volumes of 10 and 20 mL and on changes in volume measurements under changing gas conditions (oxygen level 21-100 % and from cold dry air (24 ± 2 °C) to heated humidified air (37 °C). Volume differences >10 % were considered clinically relevant. We found that the mean (SD) volume difference was clinically acceptable for all devices (10, 20 mL): Florian (+8.4 (1.2)%, +8.4 (0.5)%); NLB Neo-RSD (+5.8 (1.1)%, +4.3 (1.4)%); and NICO (-8.2 (0.9)%, -8.7 (0.8)%). Changing from cold dry to heated humidified air increased the volume difference using the Florian (cold dry air, heated humidified air (+5.2 (1.2)%, +12.2 (0.9)%) but not NLB Neo-RSD (+2.0(1.6)%, +3.4(2.8)%) and NICO (-2.3 % (0.8), +0.1 (0.6)%). Similarly, when using heated humidified air, increasing oxygen enlarged increased the volume difference using the Florian (oxygen 21 %, 100 %: +12.2(1.0)%, +19.8(1.1)%), but not NLB Neo-RSD (+0.2(1.9)%, +1.1(2.8)%) and NICO (-5.6(0.9)%, -3.7(0.9)%). Clinically relevant changes occurred when changing both gas conditions (Florian +25.7(1.7)%; NLB Neo-RSD +3.8(2.4)%; NICO -5.7(1.4)%). CONCLUSION: The available RFMs demonstrated clinically acceptable deviations in volume measurements, except for the Florian when changing gas conditions. WHAT IS KNOWN: •Respiratory function monitors (RFMs) are increasingly used for volume measurements during respiratory support of infants at birth. •During respiratory support at birth, gas conditions can change quickly, which can influence the volume measurements. What is new: •The available RFMs have clinically acceptable deviations when measuring the accuracy of volume measurements. •The RFM using a hot wire anemometer demonstrated clinically relevant deviations in volume measurements when changing the gas conditions. These deviations have to be taken into account when interpreting the volumes directly at birth.

Cardiorespiratory Monitoring during Neonatal Resuscitation for Direct Feedback and Audit.

Neonatal resuscitation is one of the most frequently performed procedures, and it is often successful if the ventilation applied is adequate. Over the last decade, interest in seeking objectivity in evaluating the infant's condition at birth or the adequacy and effect of the interventions applied has markedly increased. Clinical parameters such as heart rate, color, and chest excursions are difficult to interpret and can be very subjective and subtle. The use of ECG, pulse oximetry, capnography, and respiratory function monitoring can add objectivity to the clinical assessment. These physiological parameters, with or without the combination of video recordings, can not only be used directly to guide care but also be used later for audit and teaching purposes. Further studies are needed to investigate whether this will improve the quality of delivery room management. In this narrative review, we will give an update of the current developments in monitoring neonatal resuscitation.

The cardiovascular response to birth asphyxia is altered by the surrounding environment.

BACKGROUND: A sustained bradycardia is used as a major indicator of severe perinatal asphyxia. However, lambs asphyxiated ex utero do not exhibit the same bradycardic response as lambs asphyxiated in utero. It is possible that the local in utero environment may influence the initial cardiovascular response to asphyxia. We assessed the effect of facial immersion in water on the cardiovascular response to birth asphyxia. METHODS: Pregnant ewes (138±1 days gestation) were anaesthetised and fetuses were exteriorised and instrumented for measurement of cardiopulmonary haemodynamics. The lamb's head either remained in air (n=5) or was placed in water that was either warm (40±1°C; n=5) or at room temperature (21±1°C; n=5) before the umbilical cord was clamped to induce asphyxia. RESULTS: Heart rate after bradycardia onset was reduced in lambs asphyxiated with their head in cool water (-34±2%) and warm water (-25±4%) compared with those in air (-11±5%; p<0.05). Similarly, the decrease in blood pressure was faster in lambs with water around the face compared with those in air. From 75 s after asphyxia onset, mean and end-diastolic carotid blood flow was higher in the group asphyxiated in air (25±4 mL/kg/min), compared with the groups in water (13±3 mL/kg/min, warm water; 16±2 mL/kg/min, cool water; p<0.05). CONCLUSIONS: The cardiovascular response to birth asphyxia is altered by the presence and temperature of water surrounding the head. The previous understanding of the vagally mediated bradycardia associated with birth asphyxia may include components of the diving reflex.

A randomised trial of placing preterm infants on their back or left side after birth.

BACKGROUND: Basic life support guidelines recommend placing spontaneously breathing children and adults on their side. Though the majority of preterm newborns breathe spontaneously, they are routinely placed on their back after birth. We hypothesised that they would breathe more effectively when placed on their side. OBJECTIVE: To determine whether preterm newborns placed on their left side at birth, compared with those placed on their back, have higher preductal oxygen saturation (SpO2) at 5 min of life. DESIGN/METHODS: We randomised infants <32 weeks to be placed on their back or on their left side immediately after birth. Respiratory support was given with a T-piece and face mask with initial fraction of inspired oxygen (FiO2) of 0.3. The FiO2 was increased if SpO2 was <70% at 5 min. RESULTS: We enrolled 87 infants, 41 randomised to back and 46 to left side. The groups were well matched for demographic variables. Fourteen (6 back and 8 left side) infants did not receive respiratory support in the first 5 min. The mean (SD) SpO2 was not different between the groups (back 72 (23) % versus left side 71 (24) %, p=0.956). We observed no adverse effects of placing infants on their side and found no differences in secondary outcomes between the groups. CONCLUSIONS: Preterm infants on their left side did not have higher SpO2 at 5 min of life. Placing preterm infants on their side at birth is feasible and appears to be a reasonable alternative to placing them on their back. TRIAL REGISTRATION NUMBER: ISRCTN74486341.

The perfusion index of healthy term infants during transition at birth.

UNLABELLED: Perfusion index is a continuous parameter provided by pulse oximetry and might be useful for evaluating hemodynamic changes at birth and identifying transitional problems. The objective was to describe perfusion index values in term infants immediately after birth. Perfusion index of 71 healthy term born infants were recorded during the first 10 min after birth, using a pulse oximetry sensor placed preductally. A Wilcoxon signed-rank test was used to compare between time points. No significant trend in perfusion index could be observed in term-delivered infants. There was a significant difference between 2 and 3 min (2.4 (1.6-5.0) vs. 2.3 (1.6-3.7), p = 0.05) and between 3 and 4 min after birth (2.3 (1.6-3.7) vs. 2.1 (1.4-3.2), p < 0.001). There was no significant change in median PI values in the following 8 min. CONCLUSION: Perfusion index does not change significantly during transition at birth in healthy term infants born by normal vaginal delivery or cesarean section. Large variation in perfusion index causes monitoring this parameter to have limited value. WHAT IS KNOWN: • Perfusion index is a non-invasive indicator for peripheral perfusion. • Perfusion index values <1.24 are seen as an accurate predictor for severity of illness for infants admitted to the neonatal intensive care unit. What is new: • Although significant physiological changes occur during birth, perfusion index remains stable. • Large variation in perfusion index causes monitoring of this value to have limited value as an additional parameter for evaluating transition at birth.

Effectivity of ventilation by measuring expired CO2 and RIP during stabilisation of preterm infants at birth.

OBJECTIVE: To measure tidal volume, plethysmography changes and gas exchange during respiratory support at birth. DESIGN: The following parameters were measured: (1) expired tidal volumes (Vte (mL/kg)) using respiratory function monitoring, (2) changes in plethysmography (AU/kg) per breath using respiratory inductance plethysmography (bands placed around rib cage (RC) and abdomen (AB)) and (3) expired CO2 (ECO2) levels using a volumetric CO2 monitor. For respiratory support, a T-piece resuscitator and facemask were used with peak inspiratory pressure (PIP) 25 cm H2O and positive end expiratory pressure 5 cm H2O. Data were analysed during the sustained inflation (SI), positive pressure ventilation (PPV) and breathing on continuous positive airway pressure (CPAP). SETTING: The delivery rooms of the Leiden University Medical Center, Leiden, and V. Buzzi, Milan. PATIENTS: 15 preterm infants with a gestational age 28 (27-31) weeks and a birth weight of 1080 (994-1300) g. RESULTS: Vte for PPV inflations, PPV inflations with breathing and spontaneous breathing were significantly different (4.4 (2.5-8.6) vs 8.8 (5.7-11.4) vs 5.7 (3.3-9.8); p<0.0001)). Spontaneous breathing led to the highest ECO2 levels and during PPV, ECO2 levels were higher when the inflations coincided with breathing (32 (23-38) vs 20 (13-25) vs 2 (3-11) mm Hg; p<0.0001). Little change in plethysmography amplitude occurred during the SI, PPV and breathing at the RC. There was gain in plethysmography amplitude at the AB during the SI, PPV, but most with breathing. CONCLUSIONS: While Vte during breathing on CPAP was lower compared with PPV coinciding with breathing, breathing on CPAP was most effective in gas exchange and plethysmography amplitude gain compared with PPV and PPV coinciding with breathing.

Very Preterm Infants Failing CPAP Show Signs of Fatigue Immediately after Birth.

OBJECTIVE: To investigate the differences in breathing pattern and effort in infants at birth who failed or succeeded on continuous positive airway pressure (CPAP) during the first 48 hours after birth. METHODS: Respiratory function recordings of 32 preterm infants were reviewed of which 15 infants with a gestational age of 28.6 (0.7) weeks failed CPAP and 17 infants with a GA of 30.1 (0.4) weeks did not fail CPAP. Frequency, duration and tidal volumes (VT) of expiratory holds (EHs), peak inspiratory flows, CPAP-level and FiO2-levels were analysed. RESULTS: EH incidence increased <6 minutes after birth and remained stable thereafter. EH peak inspiratory flows and VT were similar between CPAP-fail and CPAP-success infants. At 9-12 minutes, CPAP-fail infants more frequently used smaller VTs, 0-9 ml/kg and required higher peak inspiratory flows. However, CPAP-success infants often used large VTs (>9 ml/kg) with higher peak inspiratory flows than CPAP-fail infants (71.8 ± 15.8 vs. 15.5 ± 5.2 ml/kg.s, p <0.05). CPAP-fail infants required higher FiO2 (0.31 ± 0.03 vs. 0.21 ± 0.01), higher CPAP pressures (6.62 ± 0.3 vs. 5.67 ± 0.26 cmH2O) and more positive pressure-delivered breaths (45 ± 12 vs. 19 ± 9%) (p <0.05). CONCLUSION: At 9-12 minutes after birth, CPAP-fail infants more commonly used lower VTs and required higher peak inspiratory flow rates while receiving greater respiratory support. VT was less variable and larger VT was infrequently used reflecting early signs of fatigue.

The first breaths of life: imaging studies of the human infant during neonatal transition.

The neonatal transition during birth is characterized by major physiological changes in respiratory and hemodynamic function, which are predominantly initiated by labor, lung aeration and clamping of the umbilical cord. Lung liquid clearance and lung aeration are not only important for the establishment of functional residual capacity, but these events also trigger the significant decrease in pulmonary vascular resistance and increase in pulmonary blood flow. Clamping the umbilical cord also contributes to these hemodynamic changes by increasing the systemic vascular resistance and sudden loss of a large proportion of venous return. This results in blood flow changes both through the foramen ovale and ductus arteriosus and eventually leads to closure of these structures and the separation of the pulmonary and systemic circulations. Most of the early theories describing neonatal transition are based on imaging studies of human infants from the 1900s. Some of these theories have been disproven in more recent studies using more accurate and non-invasive imaging techniques. This review will provide an overview of the theories suggested to explain the process of liquid clearance and lung recruitment and also addresses new findings in this field of research.

Mask versus Nasal Tube for Stabilization of Preterm Infants at Birth: Respiratory Function Measurements.

OBJECTIVE: To compare the nasal tube with face mask as interfaces for stabilization of very preterm infants at birth by using physiological measurements of leak, obstruction, and expired tidal volumes during positive pressure ventilation (PPV). STUDY DESIGN: In the delivery room, 43 infants <30 weeks gestation were allocated to receive respiratory support by nasal tube or face mask. Respiratory function, heart rate, and oxygen saturation were measured. Occurrence of obstruction, amount of leak, and tidal volumes were compared using a Mann-Whitney U test or a Fisher exact test. RESULTS: The first 5 minutes after initiation of PPV were analyzed (1566 inflations in the nasal tube group and 1896 inflations in the face mask group). Spontaneous breathing coincided with PPV in 32% of nasal tube and 34% of face mask inflations. During inflations, higher leak was observed using nasal tube compared with face mask (98% [33%-100%] vs 14 [0%-39%]; P < .0001). Obstruction occurred more often (8.2% vs 1.1%; P < .0001). Expired tidal volumes were significantly lower during inflations when using nasal tube compared with face mask (0.0 [0.0-3.1] vs 9.9 [5.5-12.8] mL/kg; P < .0001) and when spontaneous breathing coincided with PPV (4.4 [2.1-8.4] vs 9.6 [5.4-15.2] mL/kg; P < .0001) but were similar during breathing on continuous positive airway pressure (4.7 [2.8-6.9] vs 4.8 [2.7-7.9] mL/kg; P > 0.05). Heart rate was not significantly different between groups, but oxygen saturation was significantly lower in the nasal tube group the first 2 minutes after start of respiratory support. CONCLUSIONS: The use of a nasal tube led to large leak, more obstruction, and inadequate tidal volumes compared with face mask. TRIAL REGISTRATION: Trial registration Registered with the Dutch Trial Registry (NTR 2061) and the Australia and New Zealand Clinical Trials Register (ACTRN 12610000230055).

Cardiovascular transition at birth: a physiological sequence.

The transition to newborn life at birth involves major cardiovascular changes that are triggered by lung aeration. These include a large increase in pulmonary blood flow (PBF), which is required for pulmonary gas exchange and to replace umbilical venous return as the source of preload for the left heart. Clamping the umbilical cord before PBF increases reduces venous return and preload for the left heart and thereby reduces cardiac output. Thus, if ventilation onset is delayed following cord clamping, the infant is at risk of superimposing an ischemic insult, due to low cardiac output, on top of an asphyxic insult. Much debate has centered on the timing of cord clamping at birth, focusing mainly on the potential for a time-dependent placental to infant blood transfusion. This has prompted recommendations for delayed cord clamping for a set time after birth in infants not requiring resuscitation. However, recent evidence indicates that ventilation onset before cord clamping mitigates the adverse cardiovascular consequences caused by immediate cord clamping. This indicates that the timing of cord clamping should be based on the infant's physiology rather than an arbitrary period of time and that delayed cord clamping may be of greatest benefit to apneic infants.

The influence of crying on the ductus arteriosus shunt and left ventricular output at birth.

BACKGROUND: During neonatal transition, ductus arteriosus (DA) flow changes from right-to-left to left-to-right and contributes considerably to the increase in pulmonary blood flow. Large transpulmonary pressures generated by crying at birth can influence the DA shunt. OBJECTIVE: This study aimed to assess differences in DA shunt during quiet breathing and crying directly after birth. METHODS: In healthy term infants born by caesarean section, echocardiography was performed at 2, 5 and 10 min after birth. The velocity time integral of DA flow, DA flow ratio (right-to-left/left-to-right flow) and left ventricular output were assessed using echocardiography. Shunting was compared within each patient during crying and quiet breathing, and between time points. RESULTS: A total of 23 infants were studied. The velocity time integral of left-to-right shunting was significantly larger during the inspiratory phase of crying than during quiet breathing [12.8 (9.2-17.4) vs. 5.9 (3.9-7.7) cm at 2 min, p < 0.0001; 14.3 (11.5-22.3) vs. 6.7 (4.1-11.1) cm at 5 min, p < 0.0001, and 18.6 (14.8-22.5) vs. 6.7 (4.4-10.7) cm at 10 min, p < 0.0001, after birth]. The increase in left-to-right shunting during crying was independent from the cardiac cycle as the QRS start of shunt interval time was 138 (82) ms during crying and 156 (35) ms during quiet breathing (n.s.). The DA flow ratio was lower in infants who cried at 0-1 time points versus those who cried at 2-3 time points (n.s.) out of the 3 time points measured. Left ventricular output was higher in infants who cried at 2-3 time points versus 0-1 time points (n.s.). CONCLUSION: Crying at birth significantly influences the DA shunt during transition.

Monitoring tidal volumes in preterm infants at birth: mask versus endotracheal ventilation.

OBJECTIVE: Upper airway distention during mask ventilation could reduce gas volumes entering the lung compared with ventilation via an endotracheal tube. Therefore, respiratory tract volumes were measured in lambs and tidal volumes were compared in preterm infants before and after intubation. DESIGN: In seven preterm lambs, volumes of the airways (oropharynx, trachea, lungs) were assessed. In 10 preterm infants, delta pressures, tidal volumes and leak were measured during ventilation 2 min before (mask ventilation) and 2 min after intubation (endotracheal ventilation). Inflations coinciding with breaths were excluded. OUTCOME MEASURES: Amount of upper airway distention in lambs and differences in inspiratory and expiratory tidal volume before and after intubation. RESULTS: In lambs, the combined trachea and oropharynx contributed to 14 (12-21) % (median (IQR), whereas the oropharynx contributed to 9 (7-10) % of the total tidal volume measured at the mouth. In preterm infants, inspiratory (11.1 (7.9-22.6) mL/kg vs 5.8 (3.9-9.6) mL/kg (p=0.01)) and expiratory (8.3 (6.8-15.4) mL/kg vs 4.9 (3.9-9.6) mL/kg (p=0.02)) tidal volumes were significantly larger during mask ventilation compared with endotracheal ventilation. Leak was 18.7 (3.3-28.7) % before versus 0 (0-2.3) % after intubation (p<0.0001). Delta pressure was 23.7 (20.8-25.6) cm H2O before versus 24.8 (20.8-26.0) cm H2O after intubation (p>0.05). During mask ventilation, expiratory tidal volume increased from 10.0 (5.4-15.6) mL/kg to 11.3 (7.6-17.0) mL/kg (p=0.01), but remained unchanged during endotracheal ventilation. CONCLUSIONS: During neonatal mask ventilation, distention of the upper respiratory tract contributes to the tidal volumes measured and should be taken into account when targeting tidal volumes during mask ventilation.

Pulse oximetry measures a lower heart rate at birth compared with electrocardiography.

OBJECTIVE: To examine the effect of time after birth on heart rate (HR) measured by pulse oximetry (PO) (HRPO) and electrocardiography (ECG) (HRECG). STUDY DESIGN: HRECG and HRPO (collected at maximum sensitivity) were assessed in 53 term and preterm infants at birth. ECG electrodes and a PO sensor were attached as soon as possible and HRECG and HRPO were compared every 30 seconds from 1-10 minutes after birth. Data were compared using a Wilkinson signed-rank test. Clinical relevance (eg, HR <100 beats per minute [bpm] was tested using a McNemar test). RESULTS: Seven hundred fifty-five data pairs were analyzed. Median (IQR) gestational age was 37 (31-39) weeks. Mean (SD) starting time of PO and ECG data collection was 99 (33) vs 82 (26) seconds after birth (P = .001). In the first 2 minutes after birth, HRPO was significantly lower compared with HRECG (94 (67-144) vs 150 (91-153) bpm at 60 seconds (P < .05), 81 (60-109) vs 148 (83-170) bpm at 90 seconds (P < .001) and 83 (67-145) vs 158 (119-176) at 120 seconds (P < .001). A HR <100 bpm was more frequently observed with a PO than ECG in the first 2 minutes (64% vs 27% at 60 seconds (P = .05), 56% vs 26% at 90 seconds (P < .05) and 53% vs 21% at 120 seconds (P < .05). HR by ECG was verified by ultrasound for outflow from a subset of infants. CONCLUSIONS: In infants at birth, HRPO is significantly lower compared with ECG with clinically important differences in the first minutes.

Two-minute training for improving neonatal bag and mask ventilation.

OBJECTIVES: To test effectivity of a two-minute training consisting of a few key-points in ventilation using the self-inflating bag (SIB). STUDY DESIGN: Experienced and inexperienced caregivers were asked to mask ventilate a leak free manikin using the SIB before and after the training. Mask leak and pressures were measured using respiratory function monitoring. Pressures above 35 cm H2O were considered excessive. Parameters were compared using a Wilcoxon non-parametric test. RESULTS: Before and after the short training, experienced caregivers had minimal median (IQR) mask leak (14 (3-75) vs. 3 (0-53)%; p<0.01). Inexperienced users had large leak which reduced from 51 (7-91)% before to 11 (2-71)% after training (p<0.01). Pressures above 35 cm H2O hardly occurred in experienced caregivers (0 (0-5) vs. 0 (0-0)%; ns). In inexperienced caregivers this frequently occurred but decreased considerably after training (94 (46-100) vs. 2 (0-70)%; p<0.01). CONCLUSION: A two-minute training of bag and mask ventilation was effective. This training could be incorporated into any training program.