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.

Tidal volumes and pressures delivered by the NeoPuff T-piece resuscitator during resuscitation of term newborns.

AIM: T-piece resuscitators are commonly used for respiratory support during newborn resuscitation. This study aimed to describe delivered pressures and tidal volumes when resuscitating term newborns immediately after birth, using the NeoPuff T-piece resuscitator. METHOD: Observational study from June 2019 through March 2021 at Stavanger University Hospital, Norway, including term newborns ventilated with a T-piece resuscitator after birth, with consent to participate. Ventilation parameters of the first 100 inflations from each newborn were recorded by respiration monitors and divided into an early (inflation 1-20) and a late (inflation 21-100) phase. RESULTS: Of the 7730 newborns born, 232 term newborns received positive pressure ventilation. Of these, 129 newborns were included. In the early and the late phase, the median (interquartile range) peak inflating pressure was 30 (28-31) and 30 (27-31) mbar, and tidal volume was 4.5 (1.6-7.8) and 5.7 (2.2-9.8) ml/kg, respectively. Increased inflation times were associated with an increase in volume before plateauing at an inflation time of 0.41 s in the early phase and 0.50 s in the late phase. Inflation rates exceeding 32 per minute in the early phase and 41 per minute in the late phase were associated with lower tidal volumes. CONCLUSION: There was a substantial variation in tidal volumes despite a relatively stable peak inflating pressure. Delivered tidal volumes were at the lower end of the recommended range. Our results indicate that an inflation time of approximately 0.5 s and rates around 30-40 per minute are associated with the highest delivered tidal volumes.

Impact of immediate and continuous heart rate feedback by dry electrode ECG on time to initiation of ventilation after birth: protocol for a randomised controlled trial.

INTRODUCTION: 3%-8% of newborns need positive pressure ventilation (PPV) after birth. Heart rate (HR) is considered the most sensitive indicator of the newborns' condition and response to resuscitative interventions. According to guidelines, HR should be assessed and PPV initiated within 60 s after birth in non-breathing newborns. Dry electrode ECG can provide accurate feedback on HR immediately after birth and continuously during resuscitation. The impact of early and continuous HR feedback is unknown. METHOD AND ANALYSIS: This single-centre randomised controlled trial seeks to determine if HR feedback by dry electrode ECG immediately after birth and continuously during newborn resuscitation results in more timely initiation of PPV, improved ventilation and short-term outcomes compared with standard HR assessment.In all newborns≥34 gestational weeks, the dry electrode ECG sensor is placed on the upper abdomen immediately after birth as an additional modality of HR assessment. The device records and stores HR signals. In intervention subjects, the HR display is visible to guide decision-making and further management, in control subjects the display is masked. Standard HR assessment is by stethoscope, gel-electrode ECG and/or pulse oximetry (PO).Time of birth is registered in the Liveborn app. Time of initiation and duration of PPV is calculated from video recordings. Ventilation parameters are retrieved from the ventilation monitor, oxygen saturation and HR from the PO and gel-electrode ECG monitors.The primary endpoint is proportion of resuscitated newborns who receive PPV within 60 s after birth. To detect a 50% increase with power of 90% using an overall significance level of 0.05 and 1 interim analysis, 169 newborns are needed in each group. ETHICS AND DISSEMINATION: Approval by the Norwegian National Research Ethics Committee West (2018/338). Parental consent is sought at routine screening early in pregnancy. The results will be published in peer-reviewed journal and presented at conferences. TRIAL REGISTRATION NUMBER: NCT03849781.

Changes in heart rate from 5 s to 5 min after birth in vaginally delivered term newborns with delayed cord clamping.

OBJECTIVE: To determine heart rate centiles during the first 5 min after birth in healthy term newborns delivered vaginally with delayed cord clamping. DESIGN: Single-centre prospective observational study. SETTING: Stavanger University Hospital, Norway, March-August 2019. PATIENTS: Term newborns delivered vaginally were eligible for inclusion. Newborns delivered by vacuum or forceps or who received any medical intervention were excluded. INTERVENTIONS: A novel dry electrode electrocardiography monitor (NeoBeat) was applied to the newborn's chest immediately after birth. The newborns were placed on their mother's chest or abdomen, dried and stimulated, and cord clamping was delayed for at least 1 min. MAIN OUTCOME MEASURES: Heart rate was recorded at 1 s intervals, and the 3rd, 10th, 25th, 50th, 75th, 90th and 97th centiles were calculated from 5 s to 5 min after birth. RESULTS: 898 newborns with a mean (SD) birth weight 3594 (478) g and gestational age 40 (1) weeks were included. The heart rate increased rapidly from median (IQR) 122 (98-146) to 168 (146-185) beats per minute (bpm) during the first 30 s after birth, peaking at 175 (157-189) bpm at 61 s after birth, and thereafter slowly decreasing. The third centile reached 100 bpm at 34 s, suggesting that heart rates <100 bpm during the first minutes after birth are uncommon in healthy newborns after delayed cord clamping. CONCLUSION: This report presents normal heart rate centiles from 5 s to 5 min after birth in healthy term newborns delivered vaginally with delayed cord clamping.

Compliance with Guidelines and Efficacy of Heart Rate Monitoring during Newborn Resuscitation: A Prospective Video Study.

OBJECTIVE: Newborn resuscitation guidelines recommend initial assessment of heart rate (HR) and initiation of positive pressure ventilation (PPV) within 60 s after birth in non-breathing newborns. Pulse oximeter (PO) and electrocardiogram (ECG) are suggested methods for continuous HR monitoring during resuscitation. Our aim was to evaluate compliance with guidelines and the efficacy of PO versus ECG monitoring in real-life newborn resuscitations. METHODS: In this prospective observational study, we video recorded resuscitations of newborns ≥34 weeks of gestation receiving PPV at birth. RESULTS: 104 resuscitations were analysed. Median (IQR) time from birth to arrival at the resuscitation bay was 48 (22-68) s (n = 62), to initial HR assessment 70 (47-118) s (n = 61), and to initiation of PPV 78 (42-118) s (n = 62). Initial HR assessment (stethoscope or palpation) and initiation of PPV were achieved within 60 s for 35% of the resuscitated newborns. Time to initial HR assessment and initiating PPV was significantly longer following vaginal deliveries than caesarean sections: 84 (70-139) versus 44 (30-66) s (p < 0.001) and 93 (73-139) versus 38 (30-66) s (p < 0.001). Time from birth and sensor application to provision of a reliable HR signal from PO versus ECG was 348 (217-524) (n = 42) versus 174 (105-277) s (n = 30) (p < 0.001) and 199 (77-352) (n = 65) versus 16 (11-22) s (n = 52) (p < 0.001). CONCLUSION: Initial HR assessment and initiation of PPV were achieved within 60 s after birth in only 1/3 of newborn resuscitations. When applied for continuous HR monitoring, ECG was superior to PO in time to achieve reliable HR signals in real-life resuscitations.

Incidence of newborn resuscitative interventions at birth and short-term outcomes: a regional population-based study.

OBJECTIVES: To determine the incidence and characteristics of resuscitative interventions at different gestational ages and short-term outcomes after resuscitation. DESIGN SETTING AND PATIENTS: A prospective observational study in an unselected population at Stavanger University Hospital, Norway, from October 2016 until September 2017. INTERVENTIONS: Using a data collection form and video recordings, we registered and analysed resuscitative interventions. MAIN OUTCOME MEASURES: Incidence of continuous positive airway pressure (CPAP), positive pressure ventilation (PPV), intubation, chest compressions and intravenous fluid or epinephrine boluses. Short-term outcomes of resuscitated newborns. RESULTS: All 4693 newborns in the study period were included in the study. Two hundred and ninety-one (6.2%) newborns received interventions in the first minutes of life beyond drying and stimulation. PPV was provided in 170 (3.6%) while CPAP (without PPV) was provided in 121 (2.6%) newborns. Duration of PPV was median (IQR) 106 s (54-221). Intubations were performed in 19 (0.4%) newborns, with a mean (SD) intubation time of 47 (21) s. Ten (0.2%) newborns received chest compressions and epinephrine was administrated in three (0.1%) newborns. Sixty-three per cent of the treated newborns from 34 weeks' gestational age were returned to parental care without further follow-up. CONCLUSIONS: The need for resuscitative interventions after birth was frequent in this unselected population in a high-resource setting, but full cardiopulmonary resuscitation was rare. Short-term outcomes were good, suggesting that most newborns treated with resuscitative interventions were not severely affected.