Impact of Continuous Capnography in Ventilated Neonates: A Randomized, Multicenter Study

Transcutaneous CO2 Monitoring in Extremely Low Birth Weight Premature Infants

Extremely low birth weight (ELBW) premature infants are particularly susceptible to hypocarbia and hypercarbia, which are associated with brain and lung morbidities. Transcutaneous CO2 (TcCO2) monitoring allows for continuous non-invasive CO2 monitoring during invasive and non-invasive ventilation and is becoming more popular in the NICU. We aimed to evaluate the correlation and agreement between CO2 levels measured by a TcCO2 monitor and blood gas CO2 (bgCO2) among ELBW infants. This was a prospective observational multicenter study. All infants < 1000 g admitted to the participating NICUs during the study period were monitored by a TcCO2 monitor, if available. For each bgCO2 measured, a simultaneous TcCO2 measurement was documented. In total, 1828 pairs of TcCO2-bgCO2 values of 94 infants were collected, with a median (IQR) gestational age of 26.4 (26.0, 28.3) weeks and birth weight of 800 (702, 900) g. A moderate correlation (Pearson: r = 0.64) and good agreement (bias (95% limits of agreement)):(2.9 [-11.8, 17.6] mmHg) were found between the TcCO2 and bgCO2 values in the 25-70 mmHg TcCO2 range. The correlation between the TcCO2 and bgCO2 trends was moderate. CO2 measurements by TcCO2 are in good agreement (bias < 5 mmHg) with bgCO2 among premature infants < 1000 g during the first week of life, regardless of day of life, ventilation mode (invasive/non-invasive), and sampling method (arterial/capillary/venous). However, wide limits of agreement and moderate correlation dictate the use of TcCO2 as a complementary tool to blood gas sampling, to assess CO2 levels and trends in individual patients.

Capnometry during neonatal transport-Mini review

AIM

The aim of this review was to give an overview of available data on end-tidal CO2 (etCO2 ) monitoring, also called capnometry, during neonatal transport.

METHODS

Pubmed/MEDLINE database was searched using research question (capno* OR etCO2 OR detCO2 OR (['end tidal' OR 'end-tidal'] AND [CO2 OR 'carbon dioxide']) AND (neonat* OR infant* OR newborn*) AND transport*). All articles relevant to the topic were reviewed and summarised.

RESULTS

The lack of studies relevant to neonatal transport prompted us to extend the search to capnometry in a neonatal intensive care setting. The published studies are showing conflicting results. The different study populations, technologies used to measure etCO2 , types of etCO2 sampling and the diverse sites of blood gas tests make the data unsuitable for systematic comparison.

CONCLUSION

Further research to obtain more data on capnometry during neonatal transport will be necessary to define precisely under what circumstances can end-tidal monitoring of CO2 be reliably used in neonates during transport and also how to interpret the measured values.

Novel approaches to capturing and using continuous cardiorespiratory physiological data in hospitalized children

Continuous cardiorespiratory physiological monitoring is a cornerstone of care in hospitalized children. The data generated by monitoring devices coupled with machine learning could transform the way we provide care. This scoping review summarizes existing evidence on novel approaches to continuous cardiorespiratory monitoring in hospitalized children. We aimed to identify opportunities for the development of monitoring technology and the use of machine learning to analyze continuous physiological data to improve the outcomes of hospitalized children. We included original research articles published on or after January 1, 2001, involving novel approaches to collect and use continuous cardiorespiratory physiological data in hospitalized children. OVID Medline, PubMed, and Embase databases were searched. We screened 2909 articles and performed full-text extraction of 105 articles. We identified 58 articles describing novel devices or approaches, which were generally small and single-center. In addition, we identified 47 articles that described the use of continuous physiological data in prediction models, but only 7 integrated multidimensional data (e.g., demographics, laboratory results). We identified three areas for development: (1) further validation of promising novel devices; (2) more studies of models integrating multidimensional data with continuous cardiorespiratory data; and (3) further dissemination, implementation, and validation of prediction models using continuous cardiorespiratory data. IMPACT: We performed a comprehensive scoping review of novel approaches to capture and use continuous cardiorespiratory physiological data for monitoring, diagnosis, providing care, and predicting events in hospitalized infants and children, from novel devices to machine learning-based prediction models. We identified three key areas for future development: (1) further validation of promising novel devices; (2) more studies of models integrating multidimensional data with continuous cardiorespiratory data; and (3) further dissemination, implementation, and validation of prediction models using cardiorespiratory data.

Prevention of severe brain injury in very preterm neonates: A quality improvement initiative

OBJECTIVE

To determine the impact of neuroprotection interventions bundle on the incidence of severe brain injury or early death (intraventricular hemorrhage grade 3/4 or death by 7 days or ventriculomegaly or cystic periventricular leukomalacia on 1-month head ultrasound, primary composite outcome) in very preterm (27^0/7 to ≤ 29^6/7 weeks gestational age) infants.

STUDY DESIGN

Prospective quality improvement initiative, from April 2017-September 2019, with neuroprotection interventions bundle including cerebral NIRS, TcCO₂, and HeRO monitoring-based management algorithm, indomethacin prophylaxis, protocolized bicarbonate and inotropes use, noise reduction, and neutral positioning.

RESULT

There was a decrease in the incidence of the primary composite outcome in the intervention period on unadjusted (N = 11/99, pre-intervention to N = 0/127, intervention period, p < 0.001) and adjusted analysis (adjusted for birthweight and Apgar score <5 at 5 min, aOR = 0.042, 95% CI = 0.003-0.670, p = 0.024).

CONCLUSIONS

Neuroprotection interventions bundle was associated with significant decrease in severe brain injury or early death in very preterm infants.

Capnography in newborns under mechanical ventilation and its relationship with the measurement of CO2 in blood samples

INTRODUCTION

Monitoring the partial pressure of CO₂ (PCO₂) in newborns who require ventilation would allow avoiding hypocapnia and hypercapnia. The measurement of end-tidal carbon dioxide (ETCO₂) is an alternative rarely implemented in this population.

OBJECTIVE

To evaluate the relationship between ETCO₂ and PCO₂ in newborns.

METHODS

Cross-sectional study comparing two PCO₂ measurement methods, the conventional one by analysis of blood samples and the one estimated by ETCO₂. The study included hospitalized newborns that required conventional mechanical ventilation. The ETCO₂ was measured with a Tecme GraphNet® neo, a neonatal ventilator with an integrated capnograph, and we obtained the ETCO₂-PCO₂ gradient. We conducted correlation and Bland-Altman plot analyses to estimate the agreement.

RESULTS

A total of 277 samples (ETCO₂ / PCO₂) from 83 newborns were analyzed. The mean values ​​of ETCO₂ and PCO₂ were 41.36mmHg and 42.04mmHg. There was a positive and significant correlation between ETCO₂ and PCO₂ in the overall analysis (r=0.5402; P<.001) and in the analysis of each unit (P<.001). The mean difference was 0.68 mmHg (95% CI, -0.68 to 1.95) and was not significant. We observed a positive systematic error (PCO₂ > ETCO₂) in 2 of the units, and a negative difference in the third (PCO₂ < ETCO₂).

DISCUSSION

The correlation between ETCO and PCO₂ was significant, although the obtained values ​​were not equivalent, with differences ranging from 0.1mmHg and 20mmHg. Likewise, we found systematic errors that differed in sign (positive or negative) between institutions.

Monitoring of carbon dioxide in ventilated neonates: a prospective observational study

OBJECTIVE

To assess the reliability, accuracy and precision of distal end-tidal capnography (detCO₂) in neonates compared with transcutaneous (tcCO₂) carbon dioxide measurements.

DESIGN

Observational, prospective clinical study.

SETTING

Neonatal intensive care unit at Medical University of Vienna.

PARTICIPANTS

Conventionally ventilated neonates with a body weight between 1000 g and 3000 g.

INTERVENTION

End-tidal partial pressure of CO₂ was measured in distal position using the separate lumen of a double-lumen endotracheal tube connected to an external side-stream capnometer. Three consecutive detCO₂ and tcCO₂ values were recorded simultaneously and compared with simultaneous arterialised partial pressure of CO₂ (paCO₂) measurements in each patient.

MAIN OUTCOME MEASURES

Reliability, accuracy and precision of detCO₂ and tcCO₂ measurements compared with paCO₂ in neonates.

RESULTS

Twenty-five neonates were included with a median (range) weight at enrolment of 1410 (1010-2980) g, from which 81 simultaneous measurements of detCO₂, tcCO₂ and paCO₂ were obtained. The mean (SD) of paCO₂, detCO₂ and tcCO₂ was 45.0 (8.6) mmHg, 42.4 (8.4) mmHg and 50.4 (20.4) mmHg, respectively. The intraclass correlation between paCO₂ and detCO₂ and between paCO₂ and tcCO₂ reached 0.80 (95% CI 0.71 to 0.87, p<0.001) and 0.59 (95% CI 0.43 to 0.72, p<0.001), respectively. In the Bland-Altman analysis, bias and precision of detCO₂ with respect to paCO₂ amounted to -2.68 mmHg and 10.62 mmHg (95% CI 8.49 to 14.51), respectively. Bias and precision of tcCO₂ with respect to paCO₂ amounted to 5.39 mmHg and 17.22 mmHg (95% CI 13.21 to 23.34), respectively.

CONCLUSION

DetCO₂ had better reliability, accuracy and precision with paCO₂ than tcCO₂ in ventilated neonates without severe lung diseas.

TRIAL REGISTRATION NUMBER

NCT03758313.

Prehospital Pediatric Respiratory Distress and Airway Management Interventions: An NAEMSP Position Statement and Resource Document

Devices and techniques such as bag-valve-mask ventilation, endotracheal intubation, supraglottic airway devices, and noninvasive ventilation offer important tools for airway management in critically ill EMS patients. Over the past decade the tools, technology, and strategies used to assess and manage pediatric respiratory and airway emergencies have evolved, and evidence regarding their use continues to grow.NAEMSP recommends:Methods and tools used to properly size pediatric equipment for ages ranging from newborns to adolescents should be available to all EMS clinicians. All pediatric equipment should be routinely checked and clearly identifiable in EMS equipment supply bags and vehicles.EMS agencies should train and equip their clinicians with age-appropriate pulse oximetry and capnography equipment to aid in the assessment and management of pediatric respiratory distress and airway emergencies.EMS agencies should emphasize noninvasive positive pressure ventilation and effective bag-valve-mask ventilation strategies in children.Supraglottic airways can be used as primary or secondary airway management interventions for pediatric respiratory failure and cardiac arrest in the EMS setting.Pediatric endotracheal intubation has unclear benefit in the EMS setting. Advanced approaches to pediatric ETI including drug-assisted airway management, apneic oxygenation, and use of direct and video laryngoscopy require further research to more clearly define their risks and benefits prior to widespread implementation.If considering the use of pediatric endotracheal intubation, the EMS medical director must ensure the program provides pediatric-specific initial training and ongoing competency and quality management activities to ensure that EMS clinicians attain and maintain mastery of the intervention.Paramedic use of direct laryngoscopy paired with Magill forceps to facilitate foreign body removal in the pediatric patient should be maintained even when pediatric endotracheal intubation is not approved as a local clinical intervention.

Non-invasive carbon dioxide monitoring in neonates: methods, benefits, and pitfalls

Wide fluctuations in partial pressure of carbon dioxide (PaCO2) can potentially be associated with neurological and lung injury in neonates. Blood gas measurement is the gold standard for assessing gas exchange but is intermittent, invasive, and contributes to iatrogenic blood loss. Non-invasive carbon dioxide (CO2) monitoring has become ubiquitous in anesthesia and critical care and is being increasingly used in neonates. Two common methods of non-invasive CO2 monitoring are end-tidal and transcutaneous. A colorimetric CO2 detector (a modified end-tidal CO2 detector) is recommended by the International Liaison Committee on Resuscitation (ILCOR) and the American Academy of Pediatrics to confirm endotracheal tube placement. Continuous CO2 monitoring is helpful in trending PaCO2 in critically ill neonates on respiratory support and can potentially lead to early detection and minimization of fluctuations in PaCO2. This review includes a description of the various types of CO2 monitoring and their applications, benefits, and limitations in neonates.

Effect of electrode temperature on measurements of transcutaneous carbon dioxide partial pressure and oxygen partial pressure in very low birth weight infants

OBJECTIVES

To evaluate the accuracy and safety of measurements of transcutaneous carbon dioxide partial pressure (TcPCO2) and transcutaneous oxygen partial pressure (TcPO2) at electrode temperatures lower than the value used in clinical practice in very low birth weight infants.

METHODS

A total of 45 very low birth weight infants were enrolled. TcPCO2 and TcPO2 measurements were performed in these infants. Two transcutaneous monitors were placed simultaneously for each subject. One electrode was set and maintained at 42℃ used in clinical practice for neonates (control group), and the other was successively set at 38℃, 39℃, 40°C, and 41℃ (experimental group). The paired t-test was used to compare the measurement results between the groups. A Pearson correlation analysis was used to analyze the correlation between the measurement results of the experimental group and control group, and between the measurement results of experimental group and arterial blood gas parameters.

RESULTS

There was no significant difference in TcPCO2 between each experimental subgroup (38-41℃) and the control group. TcPCO2 in each experimental subgroup (38-41℃) was strongly positively correlated with TcPCO2 in the control group (r>0.9, P<0.05) and arterial carbon dioxide partial pressure (r>0.8, P<0.05). There were significant differences in TcPO2 between each experimental subgroup (38-41℃) and the control group (P<0.05), but TcPO2 in each experimental subgroup (38-41℃) was positively correlated with TcPO2 in the control group (r=0.493-0.574, P<0.05) and arterial oxygen partial pressure (r=0.324-0.399, P<0.05). No skin injury occurred during transcutaneous measurements at all electrode temperatures.

CONCLUSIONS

Lower electrode temperatures (38-41℃) can accurately measure blood carbon dioxide partial pressure in very low birth weight infants, and thus can be used to replace the electrode temperature of 42°C. Transcutaneous measurements at the lower electrode temperatures may be helpful for understanding the changing trend of blood oxygen partial pressure.

End-tidal capnography monitoring in infants ventilated on the neonatal intensive care unit

OBJECTIVE

To assess whether end-tidal capnography (EtCO2) monitoring reduced the magnitude of difference in carbon dioxide (CO2) levels and the number of blood gases in ventilated infants.

STUDY DESIGN

A case-control study of a prospective cohort (n = 36) with capnography monitoring and matched historical controls (n = 36).

RESULT

The infants had a median gestational age of 31.6 weeks. A reduction in the highest CO2 level on day 1 after birth was observed after the introduction of EtCO2 monitoring (p = 0.043). There was also a reduction in the magnitude of difference in CO2 levels on days 1 (p = 0.002) and 4 (p = 0.049) after birth. There was no significant difference in the number of blood gases.

CONCLUSION

Continuous end-tidal capnography monitoring in ventilated infants was associated with a reduction in the degree of the magnitude of difference in CO2 levels and highest level of CO2 on the first day after birth.

Correlation of End-Tidal Carbon Dioxide with Arterial Carbon Dioxide in Mechanically Ventilated Neonates: A Scoping Review

Monitoring CO2 levels in intubated neonates is highly relevant in the face of complications associated with altered CO2 levels. Thus, this review aims to present the scientific evidence in the literature regarding the correlation between arterial carbon dioxide measured by non-invasive methods in newborns submitted to invasive mechanical ventilation. The search was carried out from January 2020 to January 2021, in the Scopus, Medline, The Cochrane Library, Web of Science, CINAHL and Embase databases. Also, a manual search of the references of included studies was performed. The main descriptors used were: "capnography," "premature infant," "blood gas analysis," and "mechanical ventilation." As a result, 221 articles were identified, and 18 were included in this review. A total of 789 newborns were evaluated, with gestational age between 22.8 and 42.2 weeks and birth weight between 332 and 4790 g. Capnometry was the most widely used non-invasive method. In general, the correlation and agreement between the methods evaluated in the studies were strong/high. The birth weight did not influence the results. The gestational age of fewer than 37 weeks implied, in its majority, a moderate correlation and agreement. Therefore, we can conclude that there was a predominance of a strong correlation between arterial blood gases and non-invasive methods, although there are variations found in the literature. Even so, the results were promising and may provide valuable data for future studies, which are necessary to consolidate non-invasive methods as a reliable and viable alternative to arterial blood gasometry.

Effect of tidal volume and end tracheal tube leakage on end-tidal CO2 in very low birth weight infants

OBJECTIVE

To examine the extents to which low tidal volume (VT) and endotracheal tube (ETT) leakeage influence the accuracy of ETCO₂ for estimating arterial PCO₂ (PaCO₂) in very low birth weight (VLBW) infants with mechanical ventilation.

STUDY DESIGN

An observational study. We evaluated a total of 287 paired ETCO₂ and PaCO₂ values as well as VTs obtained from 22 VLBW infants with ventilation. Deming regression, quadratic discriminant analysis, and Bland-Altman analysis were performed.

RESULT

ETCO₂ and PaCO₂ were correlated (r² = 0.5897, p < 0.0001). A quadratic discrimination analysis of the VT and the percentage of leak yielded 70.4% [95%CI, 65.1 to 75.7] discrimination for the agreement between ETCO₂ and PaCO₂. ETCO₂ was strongly correlated with PaCO₂ in the discriminant function Z > 0 group (r² = 0.7234, p < 0.0001).

CONCLUSION

Our results indicate that ETCO₂ is a good surrogate for PaCO₂ when VT is high and ETT leak is low.

Comparing the novel microstream and the traditional mainstream method of end-tidal CO2 monitoring with respect to PaCO2 as gold standard in intubated critically ill children

The objective of this study was to evaluate a novel microstream method by comparison with PaCO₂ and the more standard mainstream capnometer in intubated pediatric patients. We hypothesized that the novel microstream method would superior compared to the traditional mainstream method in predicting PaCO₂. This was a prospective single-center comparative study. The study was carried out on 174 subjects with a total of 1338 values for each method. Data were collected prospectively from mainstream and microstream capnometer simultaneously and compared with PaCO₂ results. Although both mainstream PetCO₂ (mainPetCO₂) and microstream PetCO₂ (microPetCO₂) were moderately correlated (r = 0.63 and r = 0.68, respectively) with PaCO₂ values, mainPetCO₂ was in better agreement with PaCO₂ in all subjects (bias ± precision values of 3.8 ± 8.9 and 7.3 ± 8.2 mmHg, respectively). In those with severe pulmonary disease, the mainPetCO₂ and microPetCO₂ methods were highly correlated with PaCO₂ (r = 0.80 and r = 0.81, respectively); however, the biases of both methods increased (14.8 ± 9.1 mmHg and 16.2 ± 9.0 mmHg, respectively). In cases with increased physiologic dead space ventilation, the agreement levels of mainPetCO₂ and microPetCO₂ methods became distorted (bias ± precision values of 20.9 ± 11.2 and 25.0 ± 11.8 mm Hg, respectively) even though mainPetCO₂ and microPetCO₂ were highly correlated (r = 0.78 and r = 0.78, respectively). It was found that the novel microstream capnometer method for PetCO₂ measurements provided no superiority to the traditional mainstream method. Both capnometer methods may be useful in predicting the trend of PaCO₂ due to significant correlations with the gold standard measurement in cases with severe pulmonary disease or increased physiological dead space –despite reduced accuracy.

Introduction of less invasive surfactant administration (LISA), impact on diagnostic and therapeutic procedures in early life: a historical cohort study

Background

In preterm infants with Respiratory Distress Syndrome (RDS), Less Invasive Surfactant Administration (LISA) has been established to reduce the need of mechanical ventilation and might improve survival rates without bronchopulmonary dysplasia. The aim of this study was to investigate whether NICU care has changed after introduction of less invasive surfactant administration (LISA), with regard to diagnostic and therapeutic procedures in the first week of life.

Methods

Infants with gestational age < 32 weeks who received surfactant by LISA (June 2014 – December 2017, n = 169) were retrospectively compared to infants who received surfactant after intubation (January 2012 – May 2014, n = 155). Local protocols on indication for surfactant, early onset sepsis, blood transfusions and enteral feeding did not change between both study periods. Besides, as secondary outcome complications of prematurity were compared. Data was collected from electronic patient files and compared by univariate analysis through Students T-test, Mann Whitney-U test, Pearson Chi-Square test or Linear by Linear Association.

Results

All baseline characteristics of both groups were comparable. Compared to controls, LISA patients received a higher total surfactant dose (208 vs.160 mg/kg; p < 0.001), required redosing more frequently (32.5% vs. 21.3%; p = 0.023), but needed less mechanical ventilation (35.5% vs. 76.8%; p < 0.001). After LISA, infants underwent fewer X-rays (1.0 vs. 3.0, p < 0.001), blood gas examinations (3.0 vs. 5.0, p < 0.001), less inotropic drugs (9.5% vs. 18.1%; p = 0.024), blood transfusions (24.9% vs. 41.9%, p = 0.003) and had shorter duration of antibiotic therapy for suspected early onset sepsis (3.0 vs. 5.0 days, p < 0.001). Moreover, enteral feeding was advanced faster (120 vs. 100 mL/kg/d, p = 0.048) at day seven. There were no differences in complications of prematurity.

Conclusion

The introduction of LISA is associated with significantly fewer diagnostic and therapeutic procedures in the first week of life, which emphasizes the beneficial effects of LISA.

How to ventilate preterm infants with lung compliance close to circuit compliance: real-time simulations on an infant hybrid respiratory simulator

Circuit compliance close to lung compliance can create serious problems in effective and safe mechanical ventilation of preterm infants. We considered what ventilation technique is the most beneficial in this case. A hybrid (numerical-physical) simulator of infant respiratory system mechanics, the Bennett Ventilator and NICO apparatus were used to simulate pressure-controlled ventilation (PC) and volume-controlled ventilation with constant flow (VCV_CF) and descending flow (VCV_DF), under permissive hypercapnia (PHC) (6 ml kg^-1) and normocapnia (SV) (8 ml kg^-1) conditions. Respiratory rate (RR) was 36 or 48 min^-1 and PEEP was 0.3 or 0.6 kPa. Peak inspiratory pressure (PIP), mean airway pressure (MAP), and work of breathing by the ventilator (WOB) were lower (P < 0.01, 1 - β = 0.9) using the PHC strategy compared to the SV strategy. The WOB increased (P < 0.01; 1 - β = 0.9) when the RR increased. The PC, VCV_CF, and VCV_DF modes did not differ in minute ventilation produced by the ventilator (MV_V), but the PC mode delivered the highest minute ventilation to the patient (MV_T) (P < 0.01; 1 - β = 0.9) at the same PIP, MAP, and WOB. The most beneficial ventilation technique appeared to be PC ventilation with the PHC strategy, with lower RR (36 min^-1). Graphical abstract The effectiveness of an infant ventilation depending on circuit compliance to lung compliance ratio (C_v C_L ^-1) and inspiration time (T_i). V_V, V_T, tidal volume set on the ventilator and delivered to patient, respectively.

What clinical practice strategies have been shown to decrease incidence rates of intraventricular haemorrhage in preterm infants?

AIM

To answer the clinical question 'In infants about to be delivered and admitted to neonatal units, what clinical practice strategies, compared to standard care, have been shown to decrease incidence rates of intraventricular haemorrhage (IVH)?'

METHODS

MEDLINE via Ovid (1943 to 5 January 2018), Embase via Ovid (1974 to 5 January 2018) and the Cochrane Library (5 January 2018) were searched for relevant articles.

RESULTS

A total of 478 articles, after the removal of duplicates, were found and screened by title and abstract. Forty full-text articles were subsequently reviewed, and 19 were included as relevant to the structured clinical question. An additional article was included based on expert advice.

CONCLUSION

There are various levels of research evidence for clinical practice strategies to decrease the incidence rates of IVH. Higher-quality evidence suggests that antenatal corticosteroids decrease the rates of IVH, and multiple evidence-based intervention bundles implemented in the neonatal unit are associated with decreased rates of IVH.

Continuous Noninvasive Carbon Dioxide Monitoring in Neonates: From Theory to Standard of Care

Ventilatory support may affect the short- and long-term neurologic and respiratory morbidities of preterm infants. Ongoing monitoring of oxygenation and ventilation and control of adequate levels of oxygen, pressures, and volumes can decrease the incidence of such adverse outcomes. Use of pulse oximetry became a standard of care for titrating oxygen delivery, but continuous noninvasive monitoring of carbon dioxide (CO₂) is not routinely used in NICUs. Continuous monitoring of CO₂ level may be crucial because hypocarbia and hypercarbia in extremely preterm infants are associated with lung and brain morbidities, specifically bronchopulmonary dysplasia, intraventricular hemorrhage, and cystic periventricular leukomalacia. It is shown that continuous monitoring of CO₂ levels helps in maintaining stable CO₂ values within an accepted target range. Continuous monitoring of CO₂ levels can be used in the delivery room, during transport, and in infants receiving invasive or noninvasive respiratory support in the NICU. It is logical to hypothesize that this will result in better outcome for extremely preterm infants. In this article, we review the different noninvasive CO₂ monitoring alternatives and devices, their advantages and disadvantages, and the available clinical data supporting or negating their use as a standard of care in NICUs.

Automatic Nonnutritive Suck Waveform Discrimination and Feature Extraction in Preterm Infants

Background and Objective: The emergence of the nonnutritive suck (NNS) pattern in preterm infants reflects the integrity of the brain and is used by clinicians in the neonatal intensive care unit (NICU) to assess feeding readiness and oromotor development. A critical need exists for an integrated software platform that provides NNS signal preprocessing, adaptive waveform discrimination, feature detection, and batch processing of big data sets across multiple NICU sites. Thus, the goal was to develop and describe a cross-platform graphical user interface (GUI) and terminal application known as NeoNNS for single and batch file time series and frequency-domain analyses of NNS compression pressure waveforms using analysis parameters derived from previous research on NNS dynamics. Methods. NeoNNS was implemented with Python and the Tkinter GUI package. The NNS signal-processing pipeline included a low-pass filter, asymmetric regression baseline correction, NNS peak detection, and NNS burst classification. Data visualizations and parametric analyses included time- and frequency-domain view, NNS spatiotemporal index view, and feature cluster analysis to model oral feeding readiness. Results. 568 suck assessment files sampled from 30 extremely preterm infants were processed in the batch mode (<50 minutes) to generate time- and frequency-domain analyses of infant NNS pressure waveform data. NNS cycle discrimination and NNS burst classification yield quantification of NNS waveform features as a function of postmenstrual age. Hierarchical cluster analysis (based on the Tsfresh python package and NeoNNS) revealed the capability to label NNS records for feeding readiness. Conclusions. NeoNNS provides a versatile software platform to rapidly quantify the dynamics of NNS development in time and frequency domains at cribside over repeated sessions for an individual baby or among large numbers of preterm infants at multiple hospital sites to support big data analytics. The hierarchical cluster feature analysis facilitates modeling of feeding readiness based on quantitative features of the NNS compression pressure waveform.

Less is More: Modern Neonatology

Iatrogenesis is more common in neonatal intensive care units (NICUs) because the infants are vulnerable and exposed to prolonged intensive care. Sixty percent of extremely low-birth-weight infants are exposed to iatrogenesis. The risk factors for iatrogenesis in NICUs include prematurity, mechanical or non-invasive ventilation, central lines, and prolonged length of stay. This led to the notion that "less is more." In the delivery room delayed cord clamping is recommended for term and preterm infants, and suction for the airways in newborns with meconium-stained fluid is not performed anymore. As a symbol for a less aggressive attitude we use the term neonatal stabilization rather than resuscitation. Lower levels of oxygen saturations are accepted as normal during the first 10 minutes of life, and if respiratory assistance is needed, we no longer use 100% oxygen but 0.21-0.3 FiO₂, depending on gestational age and the level of oxygen saturation. We try to avoid endotracheal ventilation by using non-invasive respiratory support and administering continuous positive airway pressure early on, starting in the delivery room. If surfactant is needed, non-invasive methods of surfactant administration are utilized. Use of central lines is shortened, and early feeding of human milk is the routine. Permissive hypercapnia is allowed, and continuous non-invasive monitoring not only of the O₂ but also of CO₂ is warranted. "Kangaroo care" and Newborn Individualized Developmental Care and Assessment Program (NIDCAP) together with a calm atmosphere with parental involvement are encouraged. Whether "less is more," or not enough, is to be seen in future studies.

Poor performance of main-stream capnography in newborn infants during general anesthesia

BACKGROUND

Endtidal (ET) measurement of carbon dioxide is well established for intraoperative respiratory monitoring of adults and children, but the method's accuracy for intraoperative use in small newborn infants has been less extensively investigated.

AIMS

The aim of this study was to compare carbon dioxide from ET measurements with arterialized capillary blood samples in newborn infants during general anesthesia and surgery.

METHODS

Endtidal carbon dioxide was continuously measured during anesthesia and surgery and compared with simultaneous blood gas analyses obtained from capillary blood samples. Fifty-nine sample sets of ET to blood gas carbon dioxide were obtained from 23 prospectively enrolled infants with a gestational age of 23-41 weeks and a birth weight of 670-4110 g.

RESULTS

Endtidal levels of carbon dioxide were considerably lower in all sample sets and only 4/23 individual ET-blood gas sample pairs differed <7.5 mm Hg (1 kPa). Bland-Altman analysis indicated a poor agreement with a bias of -13 ± 7 mm Hg and a precision of ±14 mm Hg. The performance of ET measurements was particularly poor in infants weighing below 2.5 kg, in infants in need of respiratory support prior to anesthesia, and when the true (blood gas) carbon dioxide level was high, above 45 mm Hg.

CONCLUSION

Main-stream capnography during anesthesia and surgery correlated poorly to blood gas values in small and/or respiratory compromised infants. We conclude that caution should be exercised when relying solely on ET measurements to guide mechanical ventilation in the OR.

Incidence, characteristics, and survival following cardiopulmonary resuscitation in the quaternary neonatal intensive care unit

BACKGROUND

The contemporary characteristics and outcomes of cardiopulmonary resuscitation (CPR) in the neonatal intensive care unit (NICU) are poorly described. The objectives of this study were to determine the incidence, interventions, and outcomes of CPR in a quaternary referral NICU.

METHODS

Retrospective observational study of infants who received chest compressions for resuscitation in the Children's Hospital of Philadelphia NICU between April 1, 2011 and June 30, 2015. Patient, event, and survival characteristics were abstracted from the medical record and the hospital-wide resuscitation database. The primary outcome was survival to hospital discharge. Univariable and multivariable analyses were performed to identify patient and event factors associated with survival to discharge.

RESULTS

There were 1.2 CPR events per 1000 patient days. CPR was performed in 113 of 5046 (2.2%) infants admitted to the NICU during the study period. The median duration of chest compressions was 2min (interquartile range 1, 6min). Adrenaline was administered in 34 (30%) CPR events. Of 113 infants with at least one CPR event, 69 (61%) survived to hospital discharge. Factors independently associated with decreased survival to hospital discharge were inotrope treatment prior to CPR (adjusted Odds Ratio [aOR] 0.14, 95% Confidence Interval [CI] 0.04, 0.54), and adrenaline administration during CPR (aOR 0.14, 95% CI 0.04, 0.50).

CONCLUSIONS

Although it was not uncommon, the incidence of CPR was low (<3%) among infants hospitalized in a quaternary referral NICU. Infants receiving inotropic therapy prior to CPR and adrenaline administration during CPR were less likely to survive to hospital discharge.

Current methodological and technical limitations of time and volumetric capnography in newborns

Although capnography is a standard tool in mechanically ventilated adult and pediatric patients, it has physiological and technical limitations in neonates. Gas exchange differs between small and adult lungs due to the greater impact of small airways on gas exchange, the higher impact of the apparatus dead space on measurements due to lower tidal volume and the occurrence of air leaks in intubated patients. The high respiratory rate and low tidal volume in newborns, especially those with stiff lungs, require main-stream sensors with fast response times and minimal dead-space or low suction flow when using side-stream measurements. If these technical requirements are not fulfilled, the measured end-tidal CO2 (P et CO 2 ), which should reflect the alveolar CO2 and the calculated airway dead spaces, can be misleading. The aim of this survey is to highlight the current limitations of capnography in very young patients to avoid pitfalls associated with the interpretation of capnographic parameters, and to describe further developments.