Developing a neonatal unit ventilation protocol for the preterm baby

Early Bubble CPAP Protocol Implementation and Rates of Death or Severe BPD

BACKGROUND

A multidisciplinary comprehensive protocol to use bubble continuous positive airway pressure (bCPAP) as the primary respiratory support in the delivery room (DR) and the NICU was introduced. With this study, we aimed to assess the association of this change with respiratory outcomes over time.

METHODS

Infants with gestational age <32 weeks and birth weight <1250 g admitted between January 2012 and June 2020 were included and categorized into 4 periods, including pre-implementation (P0: 2012-2014), and post-implementation (P1: 2014-2016, P2: 2016-2018, P3: 2018-2020). The primary outcome was the rates of death and severe bronchopulmonary dysplasia (BPD), and the secondary outcomes included the rates of DR and NICU intubation ≤7 days of age, need of surfactant, and pneumothorax. Multivariate logistic regression models accounting for relevant risk factors were used to calculate adjusted odds ratios (ORs).

RESULTS

The study included 440 infants (P0 = 90, P1 = 91, P2 = 128, P3 = 131). Over time, more infants were free of BPD (P < .001), and the rates of death and severe BPD decreased significantly: P1 = OR 1.21 (95% confidence interval [CI] 0.56-2.67), P2 = OR 0.45 (95% CI 0.20-0.99), and P3 = OR 0.37 (95% CI 0.15-0.84). DR intubation decreased from 66% (P0) to 24% (P3) in the entire cohort (P < .001) and from 96% (P0) to 40% (P3) in infants <26 weeks of age (P < .001). The need for NICU intubation was similar (P = .98), with a decreased need for surfactant (P = .001) occurring at higher FiO2 (P0 = 0.35 vs P3 = 0.55, P < .001). Pneumothorax rates were unchanged.

CONCLUSIONS

In very preterm infants, the implementation of a comprehensive bCPAP protocol led to a significant and consistent improvement in respiratory practices and the rates of death and severe BPD.

Volume-targeted ventilation

Despite strong evidence of important benefits of volume-targeted ventilation, many high-risk extremely preterm infants continue to receive traditional pressure-controlled ventilation in the United States and elesewhere. Reluctance to abandon one's comfort zone, lack of suitable equipment and a lack of understanding of the subtleties of volume-targeted ventilation appear to contribute to the relatively slow uptake of volume-targeted ventilation. This review will underscore the benefits of using tidal volume as the primary control variable, to improve clinicians' understanding of the way volume-targeted ventilation interacts with the awake, breathing infant and to provide information about evidence-based tidal volume targets in various circmstances. Focus on underlying lung pathophysiology, individualized ventilator settings and tidal volume targets are essential to successful use of this approach thereby improving important clinical outcomes.

Respiratory Management of the Preterm Infant: Supporting Evidence-Based Practice at the Bedside

Extremely preterm infants frequently require some form of respiratory assistance to facilitate the cardiopulmonary transition that occurs in the first hours of life. Current resuscitation guidelines identify as a primary determinant of overall newborn survival the establishment, immediately after birth, of adequate lung inflation and ventilation to ensure an adequate functional residual capacity. Any respiratory support provided, however, is an important contributing factor to the development of bronchopulmonary dysplasia. The risks correlated to invasive ventilatory techniques increase inversely with gestational age. Preterm infants are born at an early stage of lung development and are more susceptible to lung injury deriving from mechanical ventilation. Any approach aiming to reduce the global burden of preterm lung disease must implement lung-protective ventilation strategies that begin from the newborn’s first breaths in the delivery room. Neonatologists today must be able to manage both invasive and noninvasive forms of respiratory assistance to treat a spectrum of lung diseases ranging from acute to chronic conditions. We searched PubMed for articles on preterm infant respiratory assistance. Our narrative review provides an evidence-based overview on the respiratory management of preterm infants, especially in the acute phase of neonatal respiratory distress syndrome, starting from the delivery room and continuing in the neonatal intensive care unit, including a section regarding exogenous surfactant therapy.

Weaning of invasive ventilation in the neonatal intensive care: Towards standardising practice: A narrative review

To present a physiological algorithmic approach to weaning of invasive ventilation in the neonatal intensive care, focusing mainly on the preterm infant. Review of literature, consensus guidelines, expert commentaries and practice guidelines from individual units. Weaning of ventilation for extubation in the neonatal population must follow certain criteria but needs individualising based on disease process, timeline and physiology. Algorithms based on scenarios and modes of ventilation used might aid the clinician on the floor for decision-making process.

Decision to extubate extremely preterm infants: art, science or gamble?

In the modern era of neonatology, mechanical ventilation has been restricted to a smaller and more immature population of extremely preterm infants. Given the adverse outcomes associated with mechanical ventilation, every effort is made to extubate these infants as early as possible. However, the scientific basis for determining extubation readiness remains imprecise and primarily guided by clinical judgement, which is highly variable and subjective. In the absence of accurate tools to assess extubation readiness, many infants fail their extubation attempt and require reintubation, which also increases complications. Recent advances in the field have led to unravelling some of the complexities surrounding extubation in this population. This review aims to synthesise the available knowledge and provide a more evidence-based approach towards the reporting of extubation outcomes and assessment of extubation readiness in extremely preterm infants.

Rates of Bronchopulmonary Dysplasia Following Implementation of a Novel Prevention Bundle

IMPORTANCE

Bronchopulmonary dysplasia (BPD) rates in the United States remain high and have changed little in the last decade.

OBJECTIVE

To develop a consistent BPD prevention bundle in a systematic approach to decrease BPD.

DESIGN, SETTING, AND PARTICIPANTS

This quality improvement study included 484 infants with birth weights from 501 to 1500 g admitted to a level 3 neonatal intensive care unit in the Kaiser Permanente Southern California system from 2009 through 2019. The study period was divided into 3 periods: 1, baseline (2009); 2, initial changes based on ongoing cycles of Plan-Do-Study-Act (2010-2014); and 3, full implementation of successive Plan-Do-Study-Act results (2015-2019).

INTERVENTIONS

A BPD prevention system of care bundle evolved with a shared mental model that BPD is avoidable.

MAIN OUTCOMES AND MEASURES

The primary outcome was BPD in infants with less than 33 weeks' gestational age (hereafter referred to as BPD <33). Other measures included adjusted BPD <33, BPD severity grade, and adjusted median postmenstrual age (PMA) at hospital discharge. Balancing measures were adjusted mortality and adjusted mortality or specified morbidities.

RESULTS

The study population included 484 infants with a mean (SD) birth weight of 1070 (277) g; a mean (SD) gestational age of 28.6 (2.9) weeks; 252 female infants (52.1%); and 61 Black infants (12.6%). During the 3 study periods, BPD <33 decreased from 9 of 29 patients (31.0%) to 3 of 184 patients (1.6%) (P < .001 for trend); special cause variation was observed. The standardized morbidity ratio for the adjusted BPD <33 decreased from 1.2 (95% CI, 0.7-1.9) in 2009 to 0.4 (95% CI, 0.2-0.8) in 2019. The rates of combined grades 1, 2, and 3 BPD decreased from 7 of 29 patients (24.1%) to 17 of 183 patients (9.3%) (P < .008 for trend). Grade 2 BPD rates decreased from 3 of 29 patients (10.3%) to 5 of 183 patients (2.7%) (P = .02 for trend). Adjusted median PMA at home discharge decreased by 2 weeks, from 38.2 (95% CI, 37.3-39.1) weeks in 2009 to 36.8 (95% CI, 36.6-37.1) weeks during the last 3 years (2017-2019) of the full implementation period. Adjusted mortality was unchanged, whereas adjusted mortality or specified morbidities decreased significantly.

CONCLUSIONS AND RELEVANCE

A sustained low rate of BPD was observed in infants after the implementation of a detailed BPD system of care.

"Optimal surfactant delivery protocol using the bovine lipid extract surfactant: a quality improvement study"

IMPORTANCE

Episodes of severe airway obstruction (SAO) are reported during surfactant administration.

OBJECTIVE

To evaluate adherence to and impact of a surfactant protocol on adverse events.

METHODS

An evidence-based protocol for surfactant administration was developed (2011), implemented (2012) and re-implemented (2014), including three major steps: lung recruitment, manual bagging, and bolus instillation. Three epochs were evaluated: E₀ (2010), E₁ (2015) and E₂ (2018). Adherence was defined as compliance with all steps. Adverse events such as hypoxia (<80%) and severe airway obstruction (SAO) were investigated.

RESULTS

197 infants (246 administrations) were included: E₀ 81 (110), E₁ 52 (63), and E₂ 64 (73). Adherence improved from 49% (E₁) to 67% (E₂). Full adherence to protocol significantly decreased SAO from 26% to 1.25% (E₂; p < 0.005) and hypoxia/bradycardia events (5 to 0% E₂; p < 0.005), without any side effects.

CONCLUSIONS

Adherence to a surfactant administration protocol improved over time and significantly decreased important adverse events.

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.

Neonatal respiratory support strategies for the management of extremely low gestational age infants: an Italian survey

Background

We aimed to survey Delivery Room and Neonatal Intensive Care Unit (NICU) respiratory strategies dedicated to the extremely low gestational age newborn (ELGAN – GA < 28 wks) in Italy.

Methods

A questionnaire was sent to 113 Italian level III centres. A lead physician and a nurse with expertise in mechanical ventilation (MV) were identified in each unit to answer. Information about those aspects of ventilatory support considered by center’s staff as needing improvement was also collected.

Results

A 100% response rate was obtained. In the Delivery Room, sustained lung inflation was performed in 74.8% of centres, and 89.2% used NCPAP. For ELGANs who need invasive MV, conventional MV was the most used strategy. Volume-targeted ventilation and High-frequency oscillatory ventilation (HFOV) were considered as primary mode in < 30% of centres. Among non-invasive strategies, NCPAP was the most utilized, followed by BiPAP, High-flow nasal cannula and nasal intermittent positive pressure ventilation. Nurses more commonly recorded in the nursing charts the ventilator’s setting parameters rather than measured ones. HFOV and non-invasive ventilation were the most quoted aspects of neonatal ventilation felt as to be improved.

Conclusion

The routine respiratory support practices in Italy showed marked variations among units. Focused interventions are largely required to improve clinical practice.

Volume-targeted ventilation: one size does not fit all. Evidence-based recommendations for successful use

Despite level 1 evidence for important benefits of volume-targeted ventilation (VTV), many vulnerable extremely preterm infants continue to be exposed to traditional pressure-controlled ventilation. Lack of suitable equipment and a lack of appreciation of the fact that 'one size does NOT fit all' appear to contribute to the slow uptake of VTV. This review attempts to improve clinicians' understanding of the way VTV works and to provide essential information about evidence-based tidal volume (V_T) targets. Focus on underlying lung pathophysiology, individualised ventilator settings and V_Ttargets are keys to successful use of VTV thereby improving important clinical outcomes.

Optimal Conventional Mechanical Ventilation in Full-Term Newborns: A Systematic Review

BACKGROUND

Most studies examining the best mechanical ventilation strategies in newborn infants have been performed in premature infants with respiratory distress syndrome.

PURPOSE

To identify and synthesize the evidence regarding optimal mechanical ventilation strategies in full-term newborns.

METHODS

Systematic review carried out according to the methods described in the PRISMA statement.

SEARCH STRATEGY

Searches in MEDLINE, EMBASE, CINAHL, and the Cochrane Library in March 2017, with an updated search and hand searches of reference lists of relevant articles in August 2017.

STUDY SELECTION

Studies were included if they were published between 1996 and 2017, involved newborns with gestational age of 37 to 42 weeks, were randomized controlled trials, intervention or crossover studies, and addressed outcomes affecting oxygenation and/or ventilation, and/or short-term outcomes including duration of mechanical ventilation. Because of the large heterogeneity between the studies, it was not possible to synthesize the results in meta-analyses. The results are presented according to thematic analysis.

RESULTS

No individual study reported research exclusively in newborns 37 to 42 weeks of gestation. Eight studies fulfilled the inclusion criteria, but the population in all these studies included both premature and term newborns. Evidence about mechanical ventilation tailored exclusively to full-term newborns is scarce.

IMPLICATION FOR PRACTICE

Synchronized intermittent mandatory ventilation with a 6 mL/kg tidal volume and a positive end-expiratory pressure of 8 cm H2O may be advantageous in full-term newborns.

IMPLICATION FOR RESEARCH

There is an urgent need for high-quality studies, preferably randomized controlled trials, in full-term newborns requiring mechanical ventilation to optimize oxygenation, ventilation, and short-term outcomes, potentially stratified according to the underlying pathology.

Application of end-tidal carbon dioxide monitoring via distal gas samples in ventilated neonates

BACKGROUND

Previous research has suggested correlations between the end-tidal partial pressure of carbon dioxide (P_ETCO₂) and the partial pressure of arterial carbon dioxide (PaCO₂) in mechanically ventilated patients, but both the relationship between P_ETCO₂ and PaCO₂ and whether P_ETCO₂ accurately reflects PaCO₂ in neonates and infants are still controversial. This study evaluated remote sampling of P_ETCO₂ via an epidural catheter within an endotracheal tube to determine the procedure's clinical safety and efficacy in the perioperative management of neonates.

METHODS

Abdominal surgery was performed under general anesthesia in 86 full-term newborns (age 1-30 days, weight 2.55-4.0 kg, American Society of Anesthesiologists class I or II). The infants were divided into 2 groups (n = 43 each), and carbon dioxide (CO₂) gas samples were collected either from the conventional position (the proximal end) or a modified position (the distal end) of the epidural catheter.

RESULTS

The P_ETCO₂ measured with the new method was significantly higher than that measured with the traditional method, and the difference between P_ETCO₂ and PaCO₂ was also reduced. The accuracy of P_ETCO₂ measured increased from 78.7% to 91.5% when the modified sampling method was used. The moderate correlation between P_ETCO₂ and PaCO₂ by traditional measurement was 0.596, which significantly increased to 0.960 in the modified sampling group. Thus, the P_ETCO₂ value was closer to that of PaCO₂.

CONCLUSION

P_ETCO₂ detected via modified carbon dioxide monitoring had a better accuracy and correlation with PaCO₂ in neonates.

Lung-protective ventilatory strategies in intubated preterm neonates with RDS

This article provides a narrative review of lung-protective ventilatory strategies (LPVS) in intubated preterm infants with RDS. A description of strategies is followed by results on short-and long-term respiratory and neurodevelopmental outcomes. Strategies will include patient-triggered or synchronized ventilation, volume targeted ventilation, the technique of intubation, surfactant administration and rapid extubation to NCPAP (INSURE), the open lung concept, strategies of high-frequency ventilation, and permissive hypercapnia. Based on this review single recommendations on optimal LPVS cannot be made. Combinations of several strategies, individually applied, most probably minimize or avoid potential serious respiratory and cerebral complications like bronchopulmonary dysplasia and cerebral palsy.

Special Considerations in Neonatal Mechanical Ventilation

Care of infants supported with mechanical ventilation is complex, time intensive, and requires constant vigilance by an expertly prepared health care team. Current evidence must guide nursing practice regarding ventilated neonates. This article highlights the importance of common language to establish a shared mental model and enhance clear communication among the interprofessional team. Knowledge regarding the underpinnings of an open lung strategy and the interplay between the pathophysiology and individual infant's response to a specific ventilator strategy is most likely to result in a positive clinical outcome.

Variation in NICU Admission Rates Without Identifiable Cause

OBJECTIVES

Admission to the NICU is influenced by physiologic compromise and by hospital care protocols. Providing appropriate care must be balanced with adverse consequences of NICU admission, such as interrupting maternal-infant bonding and unnecessary interventions. This study aims to determine the variation in NICU admissions in term and late preterm infants among 19 hospitals.

METHODS

We used the Consortium on Safe Labor (CSL) database to determine NICU admission rates. This database includes data from 217 442 infants aged 35 to 42 weeks within 19 US maternal delivery hospitals from 2002 to 2008. NICU admission rates were evaluated for absolute factors including, but not limited to, sepsis, asphyxia, respiratory distress, and intracranial hemorrhage, as well as relative factors, such as maternal drug use, chorioamnionitis, and infant birth weight ≤ 2500 g.

RESULTS

Percentage of infants 35 to 42 weeks' gestation admitted to the NICU without an identifiable absolute or relative cause for intensive care services ranged from 0% to 59.4% (mean, 10.8%; P < .001). Among infants 35 to 42 weeks' gestation and ≥ 2500 g, infants without absolute or relative identified cause accounted for 9.1% of total NICU days and had lower length of stays (-2.7 days; 95% confidence interval -3.4; -2.1) compared to those with an identified reason.

CONCLUSIONS

There is significant variation in admission rates among NICUs that cannot be explained by infant health conditions. Further analysis is needed to determine the cause of between-site variation and potential opportunities to refine protocols and optimize use of NICU services.

International survey on periextubation practices in extremely preterm infants

OBJECTIVE

To determine periextubation practices in extremely preterm infants (<28 weeks gestation).

DESIGN

A survey consisting of 13 questions related to weaning from mechanical ventilation, assessment of extubation readiness and postextubation respiratory support was developed and sent to clinical directors of level III NICUs in Australia, Canada, Ireland, New Zealand and USA. A descriptive analysis of the results was performed.

RESULTS

112/162 (69%) units responded; 36% reported having a guideline (31%) or written protocol (5%) for ventilator weaning. Extubation readiness was assessed based on ventilatory settings (98%), blood gases (92%) and the presence of clinical stability (86%). Only 54% ensured that infants received caffeine ≤24 h prior to extubation. 16% of units systematically extubated infants on the premise that they passed a Spontaneous Breathing Test with a duration ranging from 3 min (25%) to more than 10 min (35%). Nasal continuous positive airway pressure was the most common type of respiratory support used (84%) followed by nasal intermittent positive pressure ventilation (55%) and high-flow nasal cannula (33%). Reintubation was mainly based on clinical judgement of the responsible physician (88%). There was a lack of consensus on the time frame for definition of extubation failure (EF), the majority proposing a period between 24 and 72 h; 43% believed that EF is an independent risk factor for increased mortality and morbidity.

CONCLUSIONS

Periextubation practices vary considerably; decisions are frequently physician dependent and not evidence based. The definition of EF is variable and well-defined criteria for reintubation are rarely used. High-quality trials are required to inform guidelines and standardise periextubation practices.

The use of mechanical ventilation protocols in Canadian neonatal intensive care units

OBJECTIVES

To identify the proportion of Canadian neonatal intensive care units with existing mechanical ventilation protocols and to determine the characteristics and respiratory care practices of units that have adopted such protocols.

METHODS

A structured survey including 36 questions about mechanical ventilation protocols and respiratory care practices was mailed to the medical directors of all tertiary care neonatal units in Canada and circulated between December 2012 and March 2013.

RESULTS

Twenty-four of 32 units responded to the survey (75%). Of the respondents, 91% were medical directors and 71% worked in university hospitals. Nine units (38%) had at least one type of mechanical ventilation protocol, most commonly for the acute and weaning phases. Units with pre-existing protocols were more commonly university-affiliated and had higher ratios of ventilated patients to physicians or respiratory therapists, although this did not reach statistical significance. The presence of a mechanical ventilation protocol was highly correlated with the coexistence of a protocol for noninvasive ventilation (P<0.001, OR 4.5 [95% CI 1.3 to 15.3]). There were overall wide variations in ventilation practices across units. However, units with mechanical ventilation protocols were significantly more likely to extubate neonates from the assist control mode (P=0.039, OR 8.25 [95% CI 1.2 to 59]).

CONCLUSION

Despite the lack of compelling evidence to support their use in neonates, a considerable number of Canadian neonatal intensive care units have adopted mechanical ventilation protocols. More research is needed to better understand their role in reducing unnecessary variations in practice and improving short- and long-term outcomes.

The need for predictability in coordination of ventilator treatment of newborn infants--a qualitative study

OBJECTIVE

New strategies for interprofessional collaboration are needed to achieve best practice in the care of ventilated newborns. This study explores what physicians and nurses believe to be important to improve collaboration during ventilator treatment.

METHODS

Qualitative data collected from one focus group were analysed using Gittell's theory of relational coordination.

RESULTS

To optimise communication about and coordination of ventilator treatment, six strategies were needed: (1) a pathway toward the goal for each newborn, (2) regular meetings, (3) accurate communication following an established pattern in the rounds conference, (4) collaboration to improve interprofessional level of knowledge, (5) courage to communicate one's own point of view, and (6) flexible responsibility in extubation situations.

CONCLUSION

By identifying weak areas in collaboration, nurses and physicians were inspired to suggest and discuss concrete improvements of work practices in the neonatal intensive care unit. Nurses and physicians can coordinate ventilator treatment by using a pathway and at the same time enhance nurses' involvement and responsibility in order to increase the flexibility of job boundaries, allowing the professions to cover for each other's work.

A preterm pig model of lung immaturity and spontaneous infant respiratory distress syndrome

Respiratory distress syndrome (RDS) and bronchopulmonary dysplasia remain the leading causes of preterm infant morbidity, mortality, and lifelong disability. Research to improve outcomes requires translational large animal models for RDS. Preterm pigs delivered by caesarian section at gestation days (GD) 98, 100, 102, and 104 were provided 24 h of neonatal intensive care, monitoring (pulse oximetry, blood gases, serum biomarkers, radiography), and nutritional support, with or without intubation and mechanical ventilation (MV; pressure control ventilation with volume guarantee). Spontaneous development of RDS and mortality without MV are inversely related with GD at delivery and correspond with inadequacy of tidal volume and gas exchange. GD 98 and 100 pigs have consolidated lungs, immature alveolar architecture, and minimal surfactant protein-B expression, and MV is essential at GD 98. Although GD 102 pigs had some alveoli lined by pneumocytes and surfactant was released in response to MV, blood gases and radiography revealed limited recruitment 1-2 h after delivery, and mortality at 24 h was 66% (35/53) with supplemental oxygen provided by a mask and 69% (9/13) with bubble continuous positive airway pressure (8-9 cmH2O). The lungs at GD 104 had higher densities of thin-walled alveoli that secreted surfactant, and MV was not essential. Between GD 98 and 102, preterm pigs have ventilation inadequacies and risks of RDS that mimic those of preterm infants born during the saccular phase of lung development, are compatible with standards of neonatal intensive care, and are alternative to fetal nonhuman primates and lambs.

Understanding neonatal ventilation: strategies for decision making in the NICU

Neonatal ventilation is an integral component of care delivered in the neonatal unit. The aim of any ventilation strategy is to support the neonate's respiratory system during compromise while limiting any long-term damage to the lungs. Understanding the principles behind neonatal ventilation is essential so that health professionals caring for sick neonates and families have the necessary knowledge to understand best practice. Given the range of existing ventilation modes and parameters available, these require explanation and clarification in the context of current evidence. Many factors can influence clinical decision making on both an individual level and within the wider perspective of neonatal care.