Factors Affecting the Weaning from Nasal CPAP in Preterm Neonates

Risk Factors for Pneumothorax and Its Association with Ventilation in Neonates

OBJECTIVE

The mode of ventilation that is implicated in pneumothorax is the one at the time of its diagnosis. Although there is evidence that air leak starts many hours before it is clinically evident, there are no prior studies that have investigated the association of pneumothorax with the mode of ventilation few hours before rather than at the time of its diagnosis.

STUDY DESIGN

A retrospective case-control study was conducted in the neonatal intensive care unit (NICU) between 2006 and 2016 where cases of neonates with pneumothorax were compared with gestational age-matched control neonates without pneumothorax. Respiratory support associated with pneumothorax was classified as the mode of ventilation 6 hours before the clinical diagnosis of pneumothorax. We investigated the factors that were different between cases and controls, and between cases of pneumothorax on bubble continuous positive airway pressure (bCPAP) and invasive mechanical ventilation (IMV).

RESULT

Of the 8,029 neonates admitted in the NICU during the study period, 223 (2.8%) developed pneumothorax. Among these, 127 occurred among 2,980 (4.3%) neonates on bCPAP, 38 among 809 (4.7%) neonates on IMV, and the remaining 58 among 4,240 (1.3%) neonates on room air. Those with pneumothorax were more likely to be male, have higher body weight, require respiratory support and surfactant administration, and have bronchopulmonary dysplasia (BPD). Among those who developed pneumothorax, there were differences in the gestational age, gender, and use of antenatal steroids between those who were on bCPAP as compared to those on IMV. IMV was associated with increased odds of pneumothorax as compared to those on bCPAP in a multivariable regression analysis. Cases on IMV had higher incidence of intraventricular hemorrhage, retinopathy of prematurity, BPD, and necrotizing enterocolitis, as well as longer length of stay as compared to those on bCPAP.

CONCLUSION

Neonates who require any respiratory support have higher incidence of pneumothorax. Among those on respiratory support, those on IMV had higher odds of pneumothorax and worse clinical outcomes as compared to those on bCPAP.

KEY POINTS

· The process of air leak leading to pneumothorax in majority of neonates starts much before it is clinically diagnosed.. · It is possible to detect the air leak early in the process by subtle changes in the signs, symptoms and changes in lung function.. · True association of the ventilation associated with pneumothorax is not at the time of diagnosis of pneumothorax but few hours before it is diagnosed.. · There is higher incidence of pneumothorax in neonates on any respiratory support.. · There is significantly higher incidence of pneumothorax among neonates on invasive ventilations as compared to noninvasive ventilation after correction for all other clinical factors..

Weaning from noninvasive ventilatory support in infants with severe bronchiolitis: An observational study

BACKGROUND

The aim of the study was to analyze the weaning success, the type of weaning procedures, and weaning duration in consecutive infants hospitalized in a pediatric intensive care unit over a winter season.

METHODS

A retrospective observational study was conducted in a pediatric intensive care unit in a tertiary center. Infants hospitalized for severe bronchiolitis were included and the weaning procedure from continuous positive airway pressure (CPAP), noninvasive ventilation (NIV), or high-flow nasal cannula (HFNC) was analyzed.

RESULTS

Data from 95 infants (median age, 47 days) were analyzed. On admission, 26 (27%), 46 (49%), and 23 (24%) infants were supported with CPAP, NIV, and HFNC, respectively. Weaning failed in one (4%), nine (20%), and one (4%) infants while supported with CPAP, NIV, or HFNC, respectively (p = 0.1). In infants supported with CPAP, CPAP was stopped directly in five patients (19%) while HFNC was used as an intermediate ventilatory support in 21 (81%). The duration of weaning was shorter for HFNC (17 h, [IQR: 0-26]) than for CPAP (24 h, [14-40]) and NIV (28 h, [19-49]) (p < 0.01).

CONCLUSIONS

The weaning phase corresponds to a large proportion of noninvasive ventilatory support duration in infants with bronchiolitis. The weaning procedure following a "step-down" strategy may lead to an increase in the duration of weaning.

Noninvasive Ventilation in Preterm Infants: Factors Influencing Weaning Decisions and the Role of the Silverman-Andersen Score

The factors influencing weaning of preterm infants from noninvasive ventilation (NIV) are poorly defined and the weaning decisions are often driven by subjective judgement rather than objective measures. To standardize quantification of respiratory effort, the Silverman-Andersen Score (SAS) was included in our nursing routine. We investigated the factors that steer the weaning process and whether the inclusion of the SAS would lead to more stringent weaning. Following SAS implementation, we prospectively evaluated 33 neonates born ≤ 32 + 0 weeks gestational age. Age-, weight- and sex-matched infants born before routine SAS evaluation served as historic control. In 173 of 575 patient days, NIV was not weaned despite little respiratory distress (SAS ≤ 2), mainly due to bradycardias (60% of days without weaning), occurring alone (40%) or in combination with other factors such as apnea/desaturations. In addition, “soft factors” that are harder to grasp impact on weaning decisions, whereas the SAS overall played a minor role. Consequently, ventilation times did not differ between the groups. In conclusion, NIV weaning is influenced by various factors that override the absence of respiratory distress limiting the predictive value of the SAS. An awareness of the factors that influence weaning decisions is important as prolonged use of NIV has been associated with adverse outcome. Guidelines are necessary to standardize NIV weaning practice.

Impact of Illness Severity and Interventions on Successful Weaning from Nasal CPAP in Very Preterm Neonates: An Observational Study

This study aims to identify clinical variables that could affect successful weaning from nasal continuous positive airway pressure (NCPAP) in very preterm infants. Infants born at a gestational age (GA) of <32 weeks were retrospectively enrolled. Weaning from NCPAP was initiated when the infants were clinically stable. In the univariate analysis, GA, birth weight, body weight (BW) z-score at the time of successful NCPAP weaning, intubation, total duration of intubation, respiratory distress syndrome grade, APGAR score at the 1 and 5 min, initial shock, anemia, bronchopulmonary dysplasia, number of blood transfusions, total duration of dopamine use, administration of more than two doses of surfactant, use of aminophylline, use of a diuretic, and total duration of total parenteral nutrition were significantly associated with postmenstrual age (PMA) at the time of successful NCPAP weaning. Multivariate analysis showed that the total duration of intubation, bronchopulmonary dysplasia, and administration of more than two doses of surfactant were positively associated with PMA at the time of successful NCPAP weaning. A reverse association was noted between BW z-score and PMA at the time of successful NCPAP weaning. Sufficient nutrition and avoidance of further ventilator-induced lung injury could decrease NCPAP duration in very preterm infants.

Predictors of successful trial off continuous positive airway pressure and high flow nasal cannula in preterm infants <30 weeks' gestation: A retrospective study

OBJECTIVES

To identify the predictors of successful first trial off nasal continuous positive airway pressure (nCPAP).

METHODS

A retrospective cohort study of infants ≤29 weeks' gestation who required nCPAP for >24 h was conducted. Logistic regression was used to detect predictors for successful trial off nCPAP. Statistical analysis was performed using the SAS software.

RESULTS

A total of 727 infants were included in the analysis. Infants who were successful in their first trial off nCPAP (n = 313) were of higher gestational age (GA) and birth weight (BW), as well as a higher proportion of female infants, compared with those who were not successful (p < 0.01). When stratified by GA, a negative correlation was noted between GA and postmenstrual age at successful trial off nCPAP or high flow nasal cannula (HFNC) (r = 0.45, p < 0.01). Logistic regression analysis showed that GA (odds ratio [OR] 1.13, 95% confidence interval [CI] [1.03-1.24], p = 0.01) and percentage of time spent with an oxygen saturation over 89% in the 24 h preceding the trial off nCPAP (OR 1.08, 95% CI [1.05-1.11], p = 0.00) were independent predictors for successful trial off nCPAP.

CONCLUSION

Successful trial off nCPAP or HFNC in preterm infants is significantly associated with higher GA, BW, female gender, and the specific oxygen saturation histogram in the preceding 24-h period.

Bubble Nasal Continuous Positive Airway Pressure (bNCPAP): An Effective Low-Cost Intervention for Resource-Constrained Settings

Preterm birth complications are responsible for almost one-third of the global neonatal mortality burden, and respiratory distress syndrome remains the single most common cause of these preventable deaths. Since its inception, almost half a century ago, nasal continuous positive airway pressure (NCPAP) has evolved to become the primary modality for neonatal respiratory care in both the developed and developing world. Although evidence has demonstrated the effectiveness of low-cost bubble NCPAP in reducing newborn mortality, its widespread use is yet to be seen in resource-constrained settings. Moreover, many tertiary hospitals in developing countries still utilise an inexpensive locally assembled bNCPAP system of unknown efficacy and safety. This review provides a brief overview of the history, physiological benefits, indications, contraindications, and complications of bNCPAP. Evidence regarding the effectiveness of low-cost bNCPAP in the neonatal intensive care unit is also summarised. The article further details a locally assembled bNCPAP system used in resource-constrained settings and highlights the care package for neonates receiving bNCPAP, failure criteria, and strategies for weaning.

Weaning strategies for the withdrawal of non-invasive respiratory support applying continuous positive airway pressure in preterm infants: a systematic review and meta-analysis

BACKGROUND

The optimal method to wean preterm infants from non-invasive respiratory support (NIVRS) with nasal continuous positive airway pressure (CPAP) or high-flow nasal cannula is still unclear, and methods used vary considerably between neonatal units.

OBJECTIVE

Perform a systematic review and meta-analysis to determine the most effective strategy for weaning preterm infants born before 37 weeks' gestation from NIVRS.

METHOD

EMBASE, MEDLINE, CINAHL, Google and Cochrane Central Register of Controlled Trials were searched for randomised controlled trials comparing different weaning strategies of NIVRS in infants born before 37 weeks' gestation.

RESULTS

Fifteen trials (1.547 infants) were included. With gradual pressure wean, the relative risk of successful weaning at the first attempt was 1.30 (95% CI 0.93 to 1.83), as compared with sudden discontinuation. Infants were weaned at a later postmenstrual age (PMA) (median difference (MD) 0.93 weeks (95% CI 0.19 to 1.67)). A stepdown strategy to nasal cannula resulted in an almost 3-week reduction in the PMA at successful weaning (MD -2.70 (95% CI -3.87 to -1.52)) but was associated with a significantly longer duration of oxygen supplementation (MD 7.80 days (95% CI 5.31 to 10.28)). A strategy using interval training had no clinical benefits. None of the strategies had any effect on the risk of chronic lung disease or the duration of hospital stay.

CONCLUSION

A strategy of gradual weaning of airway pressure might increase the chances of successful weaning. Stepdown strategy from CPAP to nasal cannula is a useful alternative resulting in an earlier weaning, but the focus should remain on continued weaning in order to avoid prolonged oxygen supplementation. Interval training should probably not be used.

Oxygen saturation histograms predict nasal continuous positive airway pressure-weaning success in preterm infants

BACKGROUND

Continuous positive airway pressure (CPAP) is widely used in preterm infants. Identification of readiness for weaning from CPAP can balance benefits with risks of CPAP exposure. We tested the hypothesis that preterm infants that successfully transition off CPAP have higher oxygen saturations prior to weaning compared with infants who fail weaning from CPAP.

METHODS

This was a single-center-matched case-control study in infants ≤30 weeks' gestation receiving ≤30% FiO₂ weaned off CPAP during the first postnatal week. Cases were infants placed back on CPAP within 7 days of being taken off CPAP, whereas control infants remained off CPAP for 7 consecutive days following CPAP discontinuation. Infants were matched on gestational age at birth (±10 days). Prospectively collected histograms detailing the distribution of oxygen saturations prior to CPAP discontinuation were compared between cases and controls.

RESULTS

Over a 12-month monitoring period, 36 infants met inclusion criteria. Baseline characteristics, morbidities, and clinical variables did not differ between cases and controls. Controls achieved oxygen saturations of 95-97 and 97-100% for longer duration compared to cases (p < 0.05).

CONCLUSIONS

In preterm infants with RDS receiving CPAP and ≤30% FiO₂, infants with higher oxygen saturations had greater success in transitioning off CPAP.

Improving Respiratory Support Practices to Reduce Chronic Lung Disease in Premature Infants

Supplemental Digital Content is available in the text.

Introduction:

We implemented a bundle of respiratory care practices and optimized delivery of continuous positive airway pressure (CPAP) to reduce the incidence of chronic lung disease (CLD) among very low birth weight (VLBW) infants born before 33 weeks gestation.

Methods:

Our multidisciplinary task force utilized 6 plan-do-study-act cycles to test our interventions. The primary outcome was the quarterly percentage of infants diagnosed with CLD; other outcomes included the percentage of infants initially managed with CPAP, intubation <72 hours of age, use of a nasal cannula, and days of ventilation, oxygen, and/or CPAP. Process measures included compliance with each of the 5 components of the bundle; balancing measures included mortality and complications of prematurity.

Results:

Demographics were similar in the 55 infants born before and 76 infants born after the task force interventions, except for gestational age, which was lower before. CLD decreased by 55.5% (from 37.5% to 16.7%). Quarterly percentage of infants requiring intubation decreased from 87.5% to 40.8%. Quarterly average days of ventilation decreased from 11.2 to 6.1, and days of supplemental oxygen declined from 44.1 to 25.4, while the use of CPAP increased. There were no differences in adverse events including mortality, pneumothorax, use of postnatal steroids, or any retinopathy of prematurity. The incidence of patent ductus arteriosus declined from 60% to 33% (P < 0.01).

Conclusions:

We reduced the incidence of CLD among our very low birth weight infants born before 33 weeks gestation by over 50% without increasing any measured adverse outcomes. The incidence of patent ductus arteriosus declined.

Sudden versus gradual pressure wean from Nasal CPAP in preterm infants: a randomized controlled trial

OBJECTIVE

In preterm infants, nasal continuous positive airway pressure (NCPAP) is widely used for treatment of respiratory distress syndrome. However, the strategies for successfully weaning infants off NCPAP are still not well defined and there remains considerable variation between the methods. The objective of this study is to determine whether gradual weaning of NCPAP pressure is more successful than sudden weaning off NCPAP to room air.

STUDY DESIGN

A randomized controlled trial was conducted in a level 3 neonatal intensive care unit on 70 preterm neonates who were born between 26 and 32 weeks gestation and required NCPAP for at least 48 h. When infants were stable on NCPAP at 0.21 FiO₂ and 5 cm H₂O positive end expiratory pressure, neonates were randomized to the gradual wean group (reduction in pressure by 1 cm every 8 h until 3 cm H₂0 was reached) or to sudden wean group (one time NCPAP removal to room air). The primary outcome was a success at the first trial to wean to room air. Secondary outcomes were a number of trials, and weight and postmenstrual age (PMA) at the time of successful wean. Total number of days on NCPAP and length of stay (LOS) in the hospital were also compared between the groups.

RESULTS

Of the 70 infants included in the study, 35 were randomized to sudden group and 33 infants to gradual group (2 excluded for protocol deviation). In sudden and gradual groups, 14 and 22 infants, respectively, were weaned successfully in the first attempt (P=0.03). The infants were successfully weaned at 32.7±1.7 weeks versus 33.1±2.4 weeks (P=0.39) PMA and at a weight of 1651±290 g versus 1589±398 g (P=0.46) in the sudden and gradual groups, respectively. The total number of days on NCPAP was 27±19 days versus 32±24 days (P=0.38) and LOS was 63±25 days versus 63±22 days (P=0.99) in the sudden and gradual groups, respectively.

CONCLUSIONS

Gradual weaning method was more successful as compared to sudden weaning method in the initial trial off NCPAP. There was no difference in the PMA, weight at the time of successful wean, total days on NCPAP and LOS between the two groups.

Duration of continuous positive airway pressure in premature infants

Continuous positive airway pressure (CPAP) has been used for respiratory support in premature infants for more than 40 years and is now a cornerstone of modern neonatal care. Clinical research on CPAP has primarily focused on understanding which devices and pressure sources best implement this therapy. In contrast, less research has examined the optimal duration over which CPAP is administered. We review this aspect of CPAP therapy.

CeasIng Cpap At standarD criteriA (CICADA): predicting a successful outcome

This is a retrospective analysis of a multicentre randomised controlled trial (RCT) where we concluded that CeasIng Cpap At standerD criteriA (CICADA) in premature babies (PBs) <30 weeks gestational age (GA) was the significantly better method of ceasing CPAP. To identify factors that may influence the number of attempts to cease CPAP, we reviewed the records of 50 PBs from the RCT who used the CICADA method. PBs were grouped according to number of attempts to cease CPAP (fast group ≤2 attempts and slow group >2 attempts to cease CPAP). There were 26 (fast group) and 24 (slow group) PBs included in the analysis. Results showed significant differences in mean GA (27.8 ± 0.3 vs 26.9 ± 0.3 [weeks ± SE], p = 0.03) and birth weight ([Bwt]; 1080 ± 48.8 vs 899 ± 45.8 [grams ± SE], p = 0.01) between groups. Significantly fewer PBs in the fast group had a patent ductus arteriosus (PDA) compared to the slow group (5/26 (19.2%) vs 13/24 (54.2 %), p = 0.02). Bwt was a significant negative predictor of CPAP duration (r = -0.497, p = 0.03) and CPAP ceasing attempts (r = -0.290, p = 0.04).

CONCLUSION

PBs with a higher GA and Bwt without a PDA ceased CPAP earlier using the CICADA method. Bwt was better than GA for predicting CPAP duration and attempts to cease CPAP.

WHAT IS KNOWN

Our previous studies showed that CeasIng Cpap At standarD criteriA (CICADA) significantly reduces CPAP time, oxygen requirements and caffeine use. Some PBs however using the CICADA method required >2 attempts to cease CPAP ('slow CICADA' group).

WHAT IS NEW

PBs in the 'fast CICADA' group (<3 attempts to cease CPAP) (a) have longer gestational age and higher birth weight, (b) shorter mechanical ventilation and (c) lower incidence of patent ductus arteriosus. Attempts to cease CPAP decreased by 0.5 times per 1 week increase in GA and 0.3 times per 100-g increase in birth weight for PBs <30 weeks gestation.

Weaning preterm infants from continuous positive airway pressure: evidence for best practice

BACKGROUND

Nasal continuous positive airway pressure (NCPAP) is frequently used in preterm infants. However, there is no consensus on when and how to wean them from NCPAP.

DATA SOURCES

Based on recent publications, we have reviewed the criteria of readiness-to-wean and factors affecting weaning success. A special focus is placed on the methods of weaning from NCPAP in preterm infants.

RESULTS

Practical points of when and how to wean from NCPAP in preterm infants are explained. Preterm infants are ready to be weaned from NCPAP when they are stable on a low NCPAP pressure with no (or minimal) oxygen requirement. Methods used to wean from NCPAP include: sudden weaning of NCPAP, gradual decrease of NCPAP pressure, graded-timeoff NCPAP (cycling), weaning to high or low flow nasal cannula, and a combination of these methods. The best strategy for weaning is yet to be determined. Cyclingoff NCPAP increases the duration of NCPAP and length of hospital stay without beneficial effect on success of weaning. Gradual decrease of NCPAP pressure is more physiological and better tolerated than cycling-off NCPAP.

CONCLUSION

Further studies are needed to reach a consensus regarding the optimal timing and the best method for weaning from NCPAP in preterm infants.

High flow nasal cannula as a method for rapid weaning from nasal continuous positive airway pressure

Background:

To compare two methods of weaning premature infants from nasal continuous positive airway pressure (NCPAP).

Methods:

Between March and November 2012, 88 preterm infants who were stable on NCPAP of 5 cmH₂O with FIO₂ <30% for a minimum of 6 h were randomly allocated to one of two groups. The high flow nasal cannula (HFNC) group received HFNC with flow of 2 L/min and FIO₂ = 0.3 and then stepwise reduction of FIO₂ and then flow. The non-HFNC group was maintained on NCPAP of 5 cmH₂O and gradual reduction of oxygen until they were on FIO₂ = 0.21 for 6 h, and we had weaned them directly from NCPAP (with pressure of 5 cmH₂O) to room air.

Results:

No significant differences were found between 2 study groups with regards to gestational age, birth weight, Apgar score at 1 and 5 min after birth, patent ductus arteriosus and use of xanthines. The mean duration of oxygen therapy after randomization was significantly lower in HFNC group compared to non-HFNC group (20.6 ± 16.8 h vs. 49.6 ± 25.3 h, P < 0.001). Also, the mean length of hospital stay was significantly lower in HFNC group compared to non-HFNC group (11.3 ± 7.8 days vs. 14.8 ± 8.6 days, P = 0.04). The rate of successful weaning was not statistically different between two groups.

Conclusions:

Weaning from NCPAP to HFNC could decrease the duration of oxygen therapy and length of hospitalization in preterm infants.

Weaning of nasal CPAP in preterm infants: who, when and how? a systematic review of the literature

BACKGROUND

There is increased use of early nasal continuous positive airway pressure (NCPAP) to manage respiratory distress in preterm infants but optimal methods and factors associated with successful wean are not well defined. A systematic review was performed to define the corrected gestational age (CGA), weight to wean NCPAP and the methods associated with successful weaning of the NCPAP among preterm infants, along with factors affecting it.

METHODS

Searches were made of PubMed using the keywords-NCPAP, CPAP, weaning, withdrawal, preterm, and infants from its inception to January 1st, 2014, for studies in all languages but limited to humans. Previous reviews (including cross references) were also searched. We included all randomized and quasi-randomized controlled trials where preterm neonates were randomized to different NCPAP weaning strategies. Details of CGA, weight and methods used for weaning NCPAP were extracted along with factors which affect its withdrawal.

RESULTS

Seven studies met the search criteria. The successful wean was at 32 to 33 weeks CGA and at 1600 g. Three different methods were used for weaning were sudden, gradual pressure wean and gradual graded time off wean. Criteria for readiness, success and failure to wean were defined. Factors affecting successful weaning were intubation, anemia, infection and gastro-esophageal reflux.

CONCLUSIONS

The successful wean was at 32 to 33 weeks CGA and 1600 g. Criteria for readiness, success and failure to wean are well defined. Sudden weaning may be associated with a shorter weaning time. Future trials are needed comparing weaning methods using defined criteria for readiness and success of NCPAP wean and stratify the results by gestational age and birth weight.

From parenteral to enteral nutrition: a nutrition-based approach for evaluating postnatal growth failure in preterm infants

BACKGROUND

Nutrition practices for preterm infants include phases of parenteral nutrition (PN), full enteral nutrition (EN), and the transitional phase in between. Our aim was to identify the nutrition phases during which infants are most likely to exhibit poor growth that would affect risk for growth failure (GF) at discharge and to examine factors associated with GF.

METHODS

A retrospective chart review was conducted on infants born <32 weeks' gestation. The neonatal intensive care unit stay was divided into 3 nutrition phases: (1) full PN, (2) transitional PN + EN, and (3) full EN. Weekly growth rates were calculated, and for each growth velocity <10 g/kg/d, the coinciding phase was recorded. GF was defined as a discharge weight below the 10th percentile. The nutrition phases during which growth inadequacy predicted GF at discharge were determined, correcting for other clinical factors associated with GF.

RESULTS

In total, 156 eligible infants were identified. Seventy-six infants (49%) were discharged with weights <10%. Incidence of poor growth was highest during the transitional phase (46%) and was predictive of GF when adjusted for gestational age, birth weight, and severity of illness. Although energy intakes during the transitional phase were comparable to baseline parenteral provision, protein intakes progressively decreased ( P < .0001), consistently providing 3 g/kg/d as PN was weaned. Serum urea nitrogen also declined and was correlated with protein intake (r = -0.32, P < .001).

CONCLUSION

Growth was compromised during the transitional phase, likely related to decreased protein intake. Optimizing protein provision while PN is weaned is an important strategy to prevent postnatal growth failure.