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

Oxygen Saturation Profiles in Healthy Term Infants in Early Postnatal Life

OBJECTIVE

Oxygen saturation profiles generated by pulse oximetry are used as a clinical tool in the neonatal intensive care unit (NICU). There is limited evidence on normal oxygen saturation profile values in term infants. This study aimed to determine oxygen saturation profiles over an 8-hour monitoring period among healthy term neonates between 24 and 48 hours after birth.

STUDY DESIGN

A prospective cohort study of healthy term neonates born at 37 to 41 weeks of gestation. Preductal oxygen saturations were continuously monitored for an 8-hour period between 24 and 48 hours of life using pulse oximetry. Oxygen profile histograms were recorded for analysis. The average percent oxygen saturation (SpO2) was measured over the entire study duration for each neonate and was characterized as the fraction of time of their SpO2 reading was in each of five intervals: ≤80, 81 to 84, 85 to 89, 90 to 94, and 95 to 100%.

RESULTS

Seventy-five neonates were included in the study. Median SpO2 was 95.4%. Percentage time spent in each of the five SpO2 intervals was as follows: 0.07 (≤80), 0.15 (81-84), 0.88 (85-89), 26.9 (90-94), and 67.3% (95-100%). Eighteen infants (24%) spent the highest percentage of time in SpO2 of 90 to 94%.

CONCLUSION

This study provides reference ranges for oxygen profiles in healthy term neonates during 24 to 48 hours of life. Nearly one-quarter of newborns spent the highest percentage of time in SpO2 of 90 to 94%. This data is important when interpreting oxygen saturation profiles of term neonates admitted to the NICU.

KEY POINTS

· This study provide reference ranges for oxygen profiles in healthy term neonates during 24 to 48 hours.. · Median SpO2 was 95.4%.. · Nearly one quarter of newborns spent the highest percentage of time in SpO2 of 90 to 94%..

Utility of saturation trends to predict successful weaning of nasal CPAP in very preterm neonates - A prospective study

BACKGROUND

There is no objective criteria to wean CPAP in preterm neonates. We aimed to assess the accuracy of 'saturation trends' to predict successful CPAP discontinuation.

METHODS

We included very preterm neonates who required CPAP. Index tests were 'saturation trends'. Outcome was successful CPAP discontinuation, defined as baby stable in room air for 72 h.

RESULTS

We had 120 neonates with mean±SD gestation 28.6±1.8 weeks. 96 (80%) neonates had successful discontinuation and 24 (20%) failed. Neonates with successful discontinuation had significantly greater 'saturation trends' during 24 h before discontinuing CPAP compared to those who failed [64.3 (48.1-83.7) vs. 47.3 (23.0-65.0), p = 0.001]. Saturations > 95% while on CPAP with 21% FiO2 for > 60% time had 63% sensitivity and 70% specificity to predict successful CPAP discontinuation.

CONCLUSION

'Saturation trends' is a readily available objective parameter that can be used to guide weaning CPAP in preterm neonates.

Use of noninvasive mechanical ventilation weaning protocol in neonatal intensive care units in Brazil: a descriptive study

OBJECTIVE

This study aimed to investigate whether neonatal intensive care units (NICUs) in Brazilian hospitals use a protocol for weaning from noninvasive ventilation (NIV), how this ventilatory support is withdrawn, and whether there is consensus among the methods used by the institutions.

METHODS

A cross-sectional survey was conducted from December 2020 to February 2021, based on responses to an electronic questionnaire, filled out by physical therapists working in NICU in Brazilian hospitals about the routine of physical therapy and the use of NIV and its weaning.

RESULTS

A total of 93 answers to the electronic questionnaire met the study criteria: 52.7% were from public health institutions, with an average of 15 NICU beds (15.2±15.9), 85% of the physical therapists worked exclusively in the NICU, 34.4% of the NICU had 24-h physical therapy care, 66.7% of the units use the continuous positive airway pressure (CPAP) as ventilatory mode, and 72% the nasal prong as NIV interface; 90% of the NICU physical therapists answered that their NICU had no NIV weaning protocol, with various methods of weaning reported, the most cited being pressure weaning.

CONCLUSIONS

Most Brazilian NICUs have no NIV weaning protocol. The most used method among institutions, with or without a protocol, is pressure weaning. Although most of the participating physical therapists work exclusively in NICU, many hospitals do not have the recommended workload, which can be one of the negative factors in the organization of protocols and in the progress of ventilatory weaning.

Oxygen saturation histogram classification system to evaluate response to doxapram treatment in preterm infants

BACKGROUND

An oxygen saturation (SpO₂) histogram classification system has been shown to enable quantification of SpO₂ instability into five types, based on histogram distribution and time spent at SpO₂ ≤ 80%. We aimed to investigate this classification system as a tool to describe response to doxapram treatment in infants with severe apnea of prematurity.

METHODS

This retrospective study included 61 very-low-birth-weight infants who received doxapram. SpO₂ histograms were generated over the 24-h before and after doxapram start. Therapy response was defined as a decrease of ≥1 histogram types after therapy start.

RESULTS

The median (IQR) histogram type decreased from 4 (3-4) before to 3 (2-3) after therapy start (p < 0.001). The median (IQR) FiO₂ remained constant before (27% [24-35%]) and after (26% [22-35%]) therapy. Thirty-six infants (59%) responded to therapy within 24 h. In 34/36 (94%) of the responders, invasive mechanical ventilation (IMV) was not required during the first 72 h of therapy, compared to 15/25 (60%) of non-responders (p = 0.002). Positive and negative predictive values of the 24-h response for no IMV requirement within 72 h were 0.46 and 0.94, respectively.

CONCLUSIONS

Classification of SpO₂ histograms provides an objective bedside measure to assess response to doxapram therapy and can serve as a tool to detect changes in oxygenation status around respiratory interventions.

IMPACT

The SpO₂ histogram classification system provides a tool for quantifying response to doxapram therapy. The classification system allowed estimation of the probability of invasive mechanical ventilation requirement, already within a few hours of treatment. The SpO₂ histogram classification system allows an objective bedside assessment of the oxygenation status of the preterm infant, making it possible to assess the changes in oxygenation status in response to respiratory interventions.

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.

Changes in Use of Respiratory Support for Preterm Infants in the US, 2008-2018

IMPORTANCE

In preterm infants, mechanical ventilation (MV) is associated with adverse pulmonary and neurodevelopmental outcomes. Multiple randomized clinical trials over the past 2 decades have shown the effectiveness of early noninvasive ventilation (NIV) in decreasing the use of MV in preterm infants. The epidemiologic factors associated with respiratory support in US preterm infants and any temporal changes after these trials is unknown.

OBJECTIVE

To evaluate temporal changes in MV and noninvasive respiratory support in US preterm infants.

DESIGN, SETTING, AND PARTICIPANTS

In a cohort design, 2 large national data sets (Pediatrix Clinical Data Warehouse for the clinical cohort and National Inpatient Sample for the national cohort) were used to collect data on preterm infants (<35 weeks' gestation) without congenital anomalies who received active intensive care and were discharged home or died in the birth hospital from January 1, 2008, to December 31, 2018. Data analysis was conducted from December 10, 2019, to December 16, 2020.

EXPOSURE

Discharge year.

MAIN OUTCOME AND MEASURES

In the clinical cohort, detailed respiratory support data were generated, including days of MV and NIV modalities, and temporal trends were evaluated using multivariable modified Poisson or negative binomial regression models with discharge year as a continuous variable. In the national cohort, observed and expected national MV use were calculated.

RESULTS

Among 259 311 infants (47.2% female) in 359 neonatal intensive care units in the clinical cohort, decreases were noted in the use (from 29.4% of infants in 2008 to 18.5% in 2018, relative risk for annual change, 0.96; 95% CI, 0.95-0.96) and duration (mean days, from 10.3 in 2008 to 9.7 in 2018; rate ratio for annual change, 0.98; 95% CI, 0.97-0.98) of MV. Noninvasive ventilation use increased from 57.9% of infants in 2008 to 67.4% in 2018 (adjusted relative risk for annual change, 1.02; 95% CI, 1.02-1.03), and mean NIV duration increased by 3.2 days (95% CI, 2.9-3.6 days). With increased use of continuous positive airway pressure and nasal intermittent positive-pressure ventilation as the main factors in the increase, the mean duration of respiratory support increased from 13.8 to 15.4 days (adjusted rate ratio for annual change, 1.03; 95% CI, 1.02-1.04) from 2008 to 2018. Among 1 169 441 infants in the national cohort, MV use decreased from 22.0% in 2008 to 18.5% in 2018, with an estimated 29 700 fewer ventilated infants and 142 000 fewer days of MV than expected during this period.

CONCLUSIONS AND RELEVANCE

These findings suggest that preterm respiratory support changed significantly from 2008 to 2018, with decreased use and duration of MV, increased use and duration of NIV, and an overall increase in respiratory support duration.

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.