A Randomized Trial Comparing Efficacy of Bubble and Ventilator Derived Nasal CPAP in Very Low Birth Weight Neonates with Respiratory Distress

Bubble devices versus other pressure sources for nasal continuous positive airway pressure in preterm infants

BACKGROUND

Several types of pressure sources, including underwater bubble devices, mechanical ventilators, and the Infant Flow Driver, are used for providing continuous positive airway pressure (CPAP) to preterm infants with respiratory distress. It is unclear whether the use of bubble CPAP versus other pressure sources is associated with lower rates of CPAP treatment failure, or mortality and other morbidity.  OBJECTIVES: To assess the benefits and harms of bubble CPAP versus other pressure sources (mechanical ventilators or Infant Flow Driver) for reducing treatment failure and associated morbidity and mortality in newborn preterm infants with or at risk of respiratory distress.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2023, Issue 1); MEDLINE (1946 to 6 January 2023), Embase (1974 to 6 January 2023), Maternity & Infant Care Database (1971 to 6 January 2023), and the Cumulative Index to Nursing and Allied Health Literature (1982 to 6 January 2023). We searched clinical trials databases and the reference lists of retrieved articles.

SELECTION CRITERIA

We included randomised controlled trials comparing bubble CPAP with other pressure sources (mechanical ventilators or Infant Flow Driver) for the delivery of nasal CPAP to preterm infants.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Two review authors separately evaluated trial quality, extracted data, and synthesised effect estimates using risk ratio (RR), risk difference (RD), and mean difference. We used the GRADE approach to assess the certainty of the evidence for effects on treatment failure, all-cause mortality, neurodevelopmental impairment, pneumothorax, moderate-severe nasal trauma, and bronchopulmonary dysplasia.

MAIN RESULTS

We included 15 trials involving a total of 1437 infants. All trials were small (median number of participants 88). The methods used to generate the randomisation sequence and ensure allocation concealment were unclear in about half of the trial reports. Lack of measures to blind caregivers or investigators was a potential source of bias in all of the included trials. The trials took place during the past 25 years in care facilities internationally, predominantly in India (five trials) and Iran (four trials). The studied pressure sources were commercially available bubble CPAP devices versus a variety of mechanical ventilator (11 trials) or Infant Flow Driver (4 trials) devices.  Meta-analyses suggest that the use of bubble CPAP compared with mechanical ventilator or Infant Flow Driver CPAP may reduce the rate of treatment failure (RR 0.76, 95% confidence interval (CI) 0.60 to 0.95; (I² = 31%); RD -0.05, 95% CI -0.10 to -0.01; number needed to treat for an additional beneficial outcome 20, 95% CI 10 to 100; 13 trials, 1230 infants; low certainty evidence). The type of pressure source may not affect mortality prior to hospital discharge (RR 0.93, 95% CI 0.64 to 1.36 (I² = 0%); RD -0.01, 95% CI -0.04 to 0.02; 10 trials, 1189 infants; low certainty evidence). No data were available on neurodevelopmental impairment. Meta-analysis suggests that the pressure source may not affect the risk of pneumothorax (RR 0.73, 95% CI 0.40 to 1.34 (I² = 0%); RD -0.01, 95% CI -0.03 to 0.01; 14 trials, 1340 infants; low certainty evidence). Bubble CPAP likely increases the risk of moderate-severe nasal injury (RR 2.29, 95% CI 1.37 to 3.82 (I² = 17%); RD 0.07, 95% CI 0.03 to 0.11; number needed to treat for an additional harmful outcome 14, 95% CI 9 to 33; 8 trials, 753 infants; moderate certainty evidence). The pressure source may not affect the risk of bronchopulmonary dysplasia (RR 0.76, 95% CI 0.53 to 1.10 (I² = 0%); RD -0.04, 95% CI -0.09 to 0.01; 7 trials, 603 infants; low certainty evidence).  AUTHORS' CONCLUSIONS: Given the low level of certainty about the effects of bubble CPAP versus other pressure sources on the risk of treatment failure and most associated morbidity and mortality for preterm infants, further large, high-quality trials are needed to provide evidence of sufficient validity and applicability to inform context- and setting-relevant policy and practice.

Non-Invasive Ventilatory Strategies to Decrease Bronchopulmonary Dysplasia-Where Are We in 2021?

Recent advances in neonatology have led to the increased survival of extremely low-birth weight infants. However, the incidence of bronchopulmonary dysplasia (BPD) has not improved proportionally, partly due to increased survival of extremely premature infants born at the late-canalicular stage of lung development. Due to minimal surfactant production at this stage, these infants are at risk for severe respiratory distress syndrome, needing prolonged ventilation. While the etiology of BPD is multifactorial with antenatal, postnatal, and genetic factors playing a role, ventilator-induced lung injury is a major, potentially modifiable, risk factor implicated in its causation. Infants with BPD are at a higher risk of developing complications including sepsis, pulmonary arterial hypertension, respiratory failure, and death. Long-term problems include increased risk of hospital readmissions, respiratory infections, and asthma-like symptoms during infancy and childhood. Survivors who have BPD are also at increased risk of poor neurodevelopmental outcomes. While the ultimate solution for avoiding BPD lies in the prevention of preterm births, strategies to decrease its incidence are the need of the hour. It is time to focus on gentler modes of ventilation and the use of less invasive surfactant administration techniques to mitigate lung injury, thereby potentially decreasing the burden of BPD. In this article, we discuss the use of non-invasive ventilation in premature infants, with an emphasis on studies showing an effect on BPD with different modes of non-invasive ventilation. Practical considerations in the use of nasal intermittent positive pressure ventilation are also discussed, considering the significant heterogeneity in clinical practices and management strategies in its use.

Availability and use of continuous positive airway pressure (CPAP) for neonatal care in public health facilities in India: a cross-sectional cluster survey

OBJECTIVES

To determine the availability of continuous positive airway pressure (CPAP) and to provide an overview of its use in neonatal units in government hospitals across India.

SETTING

Cross-sectional cluster survey of a nationally representative sample of government hospitals from across India.

PRIMARY OUTCOMES

Availability of CPAP in neonatal units.

SECONDARY OUTCOMES

Proportion of hospitals where infrastructure and processes to provide CPAP are available. Case fatality rates and complication rates of neonates treated with CPAP.

RESULTS

Among 661 of 694 government hospitals with neonatal units that provided information on availability of CPAP for neonatal care, 68.3% of medical college hospitals (MCH) and 36.6% of district hospitals (DH) used CPAP in neonates. Assessment of a representative sample of 142 hospitals (79 MCH and 63 DH) showed that air-oxygen blenders were available in 50.7% (95% CI 41.4% to 60.9%) and staff trained in the use of CPAP were present in 56.0% (45.8% to 65.8%) of hospitals. The nurse to patient ratio was 7.3 (6.4 to 8.5) in MCH and 6.6 (5.5 to 8.3) in DH. Clinical guidelines were available in 31.0% of hospitals (22.2% to 41.4%). Upper oxygen saturation limits of above 94% were used in 72% (59.8% to 81.6%) of MCH and 59.3% (44.6% to 72.5%) of DH. Respiratory circuits were reused in 53.8% (42.3% to 63.9%) of hospitals. Case fatality rate for neonates treated with CPAP was 21.4% (16.6% to 26.2%); complication rates were 0.7% (0.2% to 1.2%) for pneumothorax, 7.4% (0.9% to 13.9%) for retinopathy and 1.4% (0.7% to 2.1%) for bronchopulmonary dysplasia.

CONCLUSIONS

CPAP is used in neonatal units across government hospitals in India. Neonates may be overexposed to oxygen as the means to detect and treat consequences of oxygen toxicity are insufficient. Neonates may also be exposed to nosocomial infections by reuse of disposables. Case fatality rates for neonates receiving CPAP are high. Complications might be under-reported. Support to infrastructure, training, guidelines implementation and staffing are needed to improve CPAP use.

A pilot study of improvised CPAP (iCPAP) via face mask for the treatment of adult respiratory distress in low-resource settings

BACKGROUND

Continuous positive airway pressure (CPAP) is a mode of non-invasive ventilation used to treat a variety of respiratory conditions in the emergency department and intensive care unit. In low-resource settings where ventilators are not available, the ability to improvise a CPAP system from locally available equipment would provide a previously unavailable means of respiratory support for patients in respiratory distress. This manuscript details the design of such a system and its performance in healthy volunteers.

METHODS

An improvised CPAP system was assembled from standard emergency department equipment and tested in 10 healthy volunteers (6 male, 4 female; ages 29-33). The system utilizes a water seal and high-flow air to create airway pressure; it was set to provide a pressure of 5 cmH2O for the purposes of this pilot study. Subjects used the system in a monitored setting for 30 min. Airway pressure, heart rate, oxygen saturation, and end-tidal CO2 were monitored. Comfort with the device was assessed via questionnaire.

RESULTS

The system maintained positive airway pressure for the full trial period in all subjects, with a mean expiratory pressure (EP) of 5.1 cmH2O (SD 0.7) and mean inspiratory pressure (IP) of 3.2 cmH2O (SD 0.8). There was a small decrease in average EP (5.28 vs 4.88 cmH2O, p = 0.03) and a trend toward decreasing IP (3.26 vs 3.07 cmH2O, p = 0.22) during the trial. No significant change in heart rate, O2 saturation, respiratory rate, or end-tidal CO2 was observed. The system was well tolerated, ranked an average of 4.0 on a 1-5 scale for comfort (with 5 = very comfortable).

CONCLUSIONS

This improvised CPAP system maintained positive airway pressure for 30 min in healthy volunteers. Use did not cause tachycardia, hypoxia, or hypoventilation and was well tolerated. This system may be a useful adjunctive treatment for respiratory distress in low-resource settings. Further research should test this system in settings where other positive pressure modalities are not available.