European Journal of Cardiovascular Medicine

Respiratory distress is one of the most frequently encountered clinical conditions in the neonatal period and remains a major contributor to neonatal morbidity and mortality. It affects approximately 3–7% of all live births globally, with a higher incidence in preterm infants due to pulmonary immaturity and insufficient surfactant production¹. In India, despite substantial advances in neonatal intensive care, the neonatal mortality rate (NMR) remains elevated at 30.92 per 1,000 live births. Respiratory distress is implicated in 32–52% of these neonatal deaths, highlighting the urgent need for early recognition and timely intervention².

The common etiologies of neonatal respiratory distress include respiratory distress syndrome (RDS), Meconium Aspiration Syndrome (MAS), Transient Tachypnea of the Newborn (TTN), congenital pneumonia, and perinatal asphyxia³. Management of these conditions centers around maintaining adequate oxygenation and ventilation while minimizing lung injury. Although mechanical ventilation is often life-saving, it is associated with significant risks such as barotrauma, volutrauma, nosocomial infections, and chronic lung disease including bronchopulmonary dysplasia^2,3.

Continuous Positive Airway Pressure (CPAP) has emerged as a safer and more physiological non-invasive alternative, especially in resource-limited settings where access to mechanical ventilation may be restricted³. Among CPAP modalities, bubble CPAP (bCPAP) is particularly notable for its simplicity, cost-effectiveness, and clinical efficacy. It works by maintaining functional residual capacity and reducing the work of breathing¹. Early initiation of bCPAP has been shown to reduce the need for mechanical ventilation and improve survival in preterm neonates with RDS⁴.

Several studies conducted in South Asia have demonstrated the effectiveness of bCPAP in improving outcomes in neonates with respiratory distress, including those in resource-constrained settings^4-6. These findings reinforce the importance of bCPAP as a first-line intervention in neonatal respiratory management.

This study was undertaken to evaluate the clinical profile and outcomes of neonates managed with bubble CPAP for respiratory distress at a tertiary care hospital in rural South India. The study also aimed to identify the factors influencing CPAP success or failure to inform timely and effective respiratory management in similar settings.

Study Design and Setting

This was a prospective cohort study conducted in the Neonatal Intensive Care Unit (NICU) of the Department of Paediatrics at Konaseema Institute of Medical Sciences and Research Foundation (KIMS and RF), Amalapuram, Andhra Pradesh. The study period spanned one year, from October 2022 to December 2023.

Study Population

The study included the first 100 neonates, both term and preterm, admitted to the NICU with clinical signs of respiratory distress. All enrolled neonates were initiated on Bubble Continuous Positive Airway Pressure (Bubble CPAP) as the primary mode of non-invasive ventilatory support.

Inclusion Criteria

Neonates with respiratory distress and a Downes Score between 4 and 6.

Oxygen saturation (SpO₂) <85% despite supplemental oxygen.

Exclusion Criteria

Severe respiratory distress (Downes Score >7/10).

Hemodynamic instability or significant cardiovascular compromise.

Refractory seizures.

Major congenital anomalies including airway malformations, pulmonary hypoplasia, and diaphragmatic hernia.

Intervention Protocol

All neonates fulfilling the inclusion criteria were started on bubble CPAP. Downes scoring was used to assess the severity of respiratory distress at admission. Bubble CPAP was administered using standard equipment with flow generators and nasal prongs. Positive End-Expiratory Pressure (PEEP) levels were titrated between 4–6 cm H₂O based on clinical assessment. Oxygen concentration was adjusted to maintain SpO₂ between 90–95%. Clinical reassessment, including Downes scoring, was done every 4 hours. Neonates were weaned off CPAP if Downes score decreased consistently and respiratory parameters stabilized. CPAP failure was defined as worsening respiratory distress, persistent hypoxia (FiO₂ >60%), or hypercapnia requiring mechanical ventilation.

Data Collection

A structured proforma was used to collect demographic and clinical data including gestational age, sex, mode of delivery, diagnosis, Downes score, duration of CPAP, PEEP settings, antenatal steroid administration, complications, and final outcomes.

Sample Size Calculation

The sample size was calculated using the formula:
n=(Z×σL)2

Where Z = 1.96 (for 95% confidence), σ = 4 (standard deviation), and L = 1 (allowable error).
The calculated sample size was 61.4; thus, 100 neonates were enrolled to increase study power and generalizability.

Statistical Analysis

Data were entered into Microsoft Excel and analyzed using SPSS version 30.0. Continuous variables were expressed as mean ± standard deviation. Categorical variables were summarized as frequencies and percentages. Association between clinical parameters and outcomes was assessed using Chi-square or Fisher’s exact test for categorical data, and Independent Sample t-test for continuous variables. A p-value <0.05 was considered statistically significant.

A total of 100 neonates with respiratory distress admitted to the NICU at KIMS and RF General Hospital, Amalapuram, were enrolled in this prospective cohort study.

Demographic Characteristics

Among the enrolled neonates, 56% were female and 44% were male (Table 1). Regarding gestational age distribution, 12% were <28 weeks, 33% were between 28–32 weeks, 32% were between 32–36 weeks, and 23% were term neonates (>37 weeks), reflecting a significant representation of preterm births.

Table 1: Demographic Characteristics

Mode of Delivery and Clinical Diagnosis

Of the 100 neonates, 51% were delivered via lower segment cesarean section (LSCS), and 49% via normal vaginal delivery (NVD) (Table 2). The most common diagnosis was respiratory distress syndrome (38%), followed by meconium aspiration syndrome (25%), birth asphyxia (25%), and congenital pneumonia (12%).

Table 2: Mode of Delivery and Clinical Diagnosis

Figure 1. Clinical Diagnosis of Neonates

Figure 2. Mode of Delivery

CPAP Therapy Parameters

The duration of CPAP therapy varied among neonates: 32% required support for <6 hours, 33% for 6–12 hours, 22% for 12–24 hours, and 13% for >24 hours (Table 3). Positive end-expiratory pressure (PEEP) settings at initiation were 4 cm H₂O in 44% of cases, 5 cm H₂O in 32%, and 6 cm H₂O in 24%. Assessment of respiratory distress at admission using Downes scoring revealed that most neonates presented with moderate scores: 21% scored 3, 30% scored 4, 26% scored 5, and 23% scored 6.

Table 3: CPAP Therapy Parameters

Antenatal Steroids and Complications

Exposure to antenatal corticosteroids varied: 33% of mothers received a complete course, 14% had incomplete administration, and 53% received no steroids at all. Notably, 43% of neonates developed complications during the course of CPAP therapy, including nasal trauma and pneumothorax, while 57% had an uncomplicated course (Table 4).

Table 4: Antenatal Steroids and Complications

Treatment Outcomes

Of the 100 neonates initiated on bubble CPAP, 62 (62%) responded well and were successfully weaned. However, 38 (38%) experienced CPAP failure and required escalation to invasive mechanical ventilation (Table 5).

Table 5: Treatment Outcomes

This prospective cohort study evaluated the clinical characteristics and outcomes of neonates with respiratory distress managed using bubble Continuous Positive Airway Pressure (CPAP) in a rural tertiary care hospital in South India.

The findings reaffirm that bubble CPAP is a highly effective and feasible first-line non-invasive ventilation strategy for neonates, particularly those born preterm or presenting with mild-to-moderate disease severity⁷.

The overall CPAP success rate in our study was 62%, indicating successful weaning without the need for mechanical ventilation. This is consistent with earlier studies conducted in low- and middle-income countries (LMICs), where bubble CPAP has demonstrated substantial efficacy in reducing the burden on invasive ventilatory support^7,8. The 38% failure rate was mainly associated with higher disease severity, delayed initiation of therapy, or lack of antenatal steroid administration.

Gestational age significantly influenced outcomes. Neonates born at ≥32 weeks were more likely to respond favorably to CPAP, while those <32 weeks exhibited a higher need for escalation to invasive ventilation. This observation supports previous evidence suggesting that pulmonary immaturity in extremely preterm neonates reduces the likelihood of non-invasive support success⁹.

Mode of delivery was also a determinant, with vaginally delivered neonates showing better outcomes compared to those delivered via cesarean section. This may be due to better lung fluid clearance and spontaneous initiation of breathing, consistent with earlier perinatal studies in similar populations¹⁰.

Antenatal corticosteroid exposure was strongly correlated with CPAP success (p<0.001). Corticosteroids accelerate fetal lung maturation and surfactant production, which enhances the response to CPAP therapy. Our results mirror national findings from India, where CPAP outcomes were superior among neonates whose mothers received complete antenatal steroid courses¹⁰.

The Downes score at admission also predicted outcomes. Neonates with lower Downes scores had significantly higher CPAP success, emphasizing the value of early clinical scoring systems in triaging neonates and initiating timely interventions⁹.

Although 43% of neonates experienced complications while on bubble CPAP, the majority were minor and manageable. The most common complications included nasal trauma and pneumothorax, which are consistent with complication rates reported by Mathai et al. and others⁹. Careful monitoring, proper prong sizing, and staff training can mitigate these risks.

Notably, higher CPAP success was observed among neonates diagnosed with congenital pneumonia and Meconium Aspiration Syndrome (MAS), which tend to be self-limiting with adequate non-invasive support¹¹. Conversely, neonates with severe respiratory distress syndrome (RDS) and birth asphyxia often required mechanical ventilation, highlighting the need for better perinatal care and timely referral.

In LMIC settings like India, the successful use of bubble CPAP is strongly influenced by infrastructural availability, provider training, and timely initiation^10-12. Studies have shown that contextual factors such as inconsistent access to devices, missed opportunities for early use, and variability in healthcare delivery can limit CPAP effectiveness despite its proven clinical benefits^11,12.

This study demonstrates that bubble CPAP is an effective and safe non-invasive respiratory support modality for neonates with respiratory distress, particularly in preterm infants. Early initiation of CPAP significantly improves clinical outcomes and reduces the need for mechanical ventilation.

Favorable outcomes were associated with higher gestational age, vaginal delivery, lower Downes scores, and antenatal corticosteroid exposure. Complications were minimal and largely preventable with vigilant monitoring and nursing care. Bubble CPAP is especially valuable in resource-limited settings due to its simplicity, affordability, and efficacy. Its widespread implementation in secondary and tertiary care centers can contribute substantially to reducing neonatal morbidity and mortality in developing countries.

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