JOURNAL OF TROPICAL PEDIATRICS, VOL. 60, NO. 5, 2014 Home-Made Continuous Positive Airways Pressure Device may Reduce Mortality in Neonates with Respiratory Distress in Low-Resource Setting by Subhashchandra Daga, Sameer Mhatre, Anushree Borhade, and Danish Khan Department of Pediatrics, Maharashtra Institute of Medical Education and Research (MIMER) Medical College, Talegaon Dabhade, Pune 410507, India Correspondence: Subhashchandra Daga, Department of Pediatrics, MIMER Medical College, Station Road, Talegaon Dabhade, Pune 410507, India. Tel: þ91 02 114 308 416. E-mail <subhashdaga@yahoo.com>. Summary Objective: To study the effectiveness of locally assembled low-cost version for continuous positive airway pressure (CPAP) delivery. Patients: Babies with respiratory distress from two contiguous periods, one with CPAP therapy and the other without, were compared for following parameters: birth weight, gestational age, severity of respiratory distress, as assessed by Silverman Anderson retraction score (SARS), maximum SARS, days taken for score to become 0, duration of oxygen therapy, hospital stay and the outcome. Results: The profile of subjects was comparable in two groups. Severity of respiratory distress (SARS) was significantly higher in post-cpap group. Time taken for SARS to become 0 and number of deaths were significantly lower, and the duration of oxygen administration and hospital stay were significantly higher in post-cpap group. The cost of an individual disposable CPAP unit was Rs 160 (USD 3). Conclusion: A low-cost and locally assembled CPAP delivery system may reduce neonatal mortality among babies with respiratory distress. Introduction In 2010, an estimated 3.1 million babies died during their first month of life. The vast majority (99%) occurred in low- and middle-income countries [1]. Pulmonary disorders account for 20% neonatal deaths in developed world [2]. Although, there is little information available regarding respiratory distress syndrome-specific mortality in low-income countries, it is argued that widespread use of oxygen and CPAP coupled with appropriate supportive care will have the greatest impact on decreasing neonatal mortality [3]. Although there is a general agreement about the effectiveness of CPAP in improving lung function and gas exchange, the views differ about the best delivery system. Affordability and ease of use are the deciding factors for its widespread use in areas with low resources. This study Acknowledgements The authors thank Dr Chhaya Valvi, Prof Sanjay Patole and Dr Mohan Swaminathan for their valuable suggestions. compares the outcome in newborn babies with respiratory distress, with and without CPAP delivery, using a locally assembled and inexpensive system. Methods This study was conducted at the neonatal intensive care unit (NICU) of the MIMER medical college. Newborn babies with respiratory distress from contiguous pre- and post-cpap periods, without exclusions, were compared for following parameters: birth weight, gestational age, proportion of term and preterm babies, severity of respiratory distress, as assessed by Silverman Anderson retraction score (SARS) [4], maximum SARS, days taken for the score to become 0, duration of oxygen therapy, hospital stay and the outcome. Data for pre-cpap period were collected from case records. Fifty-six babies from pre-cpap period (June and July 2012) and 84 babies from post-cpap period (August October 2012) were studied. The CPAP delivery system was composed of humidified gas source (Fig. 1), pressure-generating system consisting of a bottle containing 6 8 cm water column (Fig. 2) and ß The Author [2014]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com 343 doi:10.1093/tropej/fmu023 Advance Access published on 23 April 2014
binasal prongs as a patient interface. Dynaplast use ensured an adequate nasal seal (Fig. 3). Cut end of the nasal canula was connected to intravenous drip set (Fig. 2). A large bore needle was inserted in the rubber top to the glass bottle to prevent clogging (Fig. 4). The babies were nursed as per our center s policy. Chest radiograph was taken following CPAP for the occurrence of pneumothorax. Head box oxygen was administered for weaning from CPAP. In the pre-cpap group, head box oxygen was administered to achieve oxygen saturation between 88 and 92%. Oxygen administration was stopped by taking into consideration the natural history of the respiratory ailment and when SARS was 0 for 2 days. Outcome variables of interest were time taken for SARS to become 0, duration of oxygen administration, i.e. duration of CPAPþ, duration of head box oxygen in post-cpap group and head box oxygen in pre-cpap group, length of the NICU stay and the outcome died or discharged. We also noted whether any baby developed pneumothorax or milk aspiration. Means were compared using unpaired t-test. Distribution of variables in pre- and post-cpap periods was compared using Pearson chi-square test. A p < 0.05 was taken as significant. The study had approval of the institutional ethics committee. Results Birth weight, gestational age and the proportion of respiratory distress among term and preterm babies were comparable in two groups. The severity of respiratory distress (maximum SARS) was significantly higher among babies in the post-cpap group. Time taken for SARS to become 0 and number of deaths were significantly lower, and the duration of oxygen administration and length of the NICU stay were significantly higher in post-cpap group (Tables 1 and 2). There was no case of pneumothorax or of milk aspiration. The cost of an individual disposable CPAP unit was estimated to be Rs 160 (USD 3). Discussion CPAP, with or without surfactant, is known to reduce the need for mechanical ventilation [5, 6]. Hence, CPAP has become an integral part of neonatal respiratory distress management in developed FIG. 2. Two arms of the CPAP system. FIG. 1. Oxygen source and CPAP connection. FIG. 3. Baby with nasal seal. 344 Journal of Tropical Pediatrics Vol. 60, No. 5
countries, where it is delivered using conventional mechanical ventilators or by using mechanized bubble-cpap units. These CPAP machines are inexpensive compared with mechanical ventilators for developed countries. CPAP has reduced the need for mechanical ventilation by 50% in a country with low resources [7]. There are reports of CPAP use from developing countries [7 9] where the researchers have either used Fisher & Paykel unit costing 6300 USD [7] or a combination of de Vilbiss 515 AKS oxygen concentrator and air compressor, Whispair (700 E) [8] or a system based on Beneveniste s pediatric gas jet device [9]. Fisher & Paykel CPAP unit costs Rs 1 50 000 (USD 3000) in India, and a locally made blender costs around Rs 35 000 (USD 600), and it serves the needs of one baby at a time. Hence, these are not the feasible options for large-scale use, especially when resources are limited. Currently, 10 12 babies receive CPAP at any given time in our newborn nursery. A substantial investment will, therefore, be required if we opt for a mechanized CPAP system. In contrast, the cost of an individual disposable CPAP unit, that we use, is estimated to be Rs 160 (USD 3). Ease of care and the application of this device make it possible for nurses FIG. 4. Two arms connected by rubber tubing. Parameter to set up the system. At our center, the CPAP system was associated with a decrease in mortality among babies with respiratory distress. However, we have witnessed a significant increase in the duration of oxygen administration in post-cpap group. We attribute this to two things. Firstly, the number of babies with higher SARS was more, and secondly, survival rates were higher in that group. Importantly, there were no pneumothoraces or milk aspiration in the 84 CPAP patients. Reduced chest indrawing is well appreciated by the parents, and this reduces their anxiety to a great extent. CPAP has also been used in children with respiratory infections in FIG. 5. Glass bottle with wide bore needle. TABLE 1 Basic characteristics of participants and their comparison Pre-CPAP group (mean) Post-CPAP group (mean) t Equality of means Birth weight (kg) 2.32 2.35 0.23 0.81 Gestational age (weeks) 37.41 36.57 1.23 0.22 Maximum SARS 3.07 4.7 3.23 0.002 Duration of oxygen (days) 8.68 11.08 2.84 0.005 Hospital stay (days) 10.66 14.12 3.47 0.001 Days taken for SARS to become 0 7.48 4.95 3.61 0.001 Journal of Tropical Pediatrics Vol. 60, No. 5 345
TABLE 2 Frequency of various parameters in pre- and post-cpap groups and significance testing Parameter Frequency number and (%) Significance Pre-CPAP 56 Post-CPAP 84 Birth weight (kg) Up to 1.5 7 (12.5%) 9 (10.7%) NS Up to 1.5 2 8 (14.3%) 15 (17.9%) >2 41 (73.2) 60 (71.4%) Gestational age (weeks) Up to 32 4 (7.4%) 9 (11%) NS 33 34 2 (3.7%) 9 (11%) 35 37 20 (37%) 17 (20.7%) >37 28 (51.9) 47 (57.3) Clinical diagnosis Term babies with respiratory distress 25 (44.6%) 50 (59.5%) NS Preterm babies with respiratory distress 31 (55.4%) 34 (40.5%) Maximum Silverman score Up to 2 31 (55.4%) 18 (21.4%) 0.001 3 4 14 (25%) 35 (41.7%) 5 6 02 (3.6%) 13 (15.5%) 7 8 03 (5.4) 05 (6.0%) 9 10 06 (10.7%) 13 (15.5%) Duration of oxygen (days) Up to 5 13 (23.2%) 1 (1.2%) 0.000 6 7 07 (12.5%) 11 (13.3%) 8 10 20 (35.7%) 36 (43.4%) >10 16 (28.6%) 35 (42.2%) NICU stay (days) Up to 7 20 (35.7%) 12 (14.5%) 0.03 8 10 20 (35.7%) 36 (43.4%) 11 14 09 (16.1%) 19 (22.9%) >14 07 (12.5%) 16 (19.3%) Outcome Died 6 (10.7%) 2 (2.4%) 0.04 Discharged 50 (89.3%) 82 (97.6%) Days taken for Silverman score to become 0 Up to 5 14 (31.8%) 54 (65.1%) 0.001 6 7 12 (27.3%) 17 (20.5%) >7 18 (40.9%) 12 (14.5%) NS, Not Significant. developing countries [10]. Therefore, our CPAP system may find wider application in pediatric care as well. Some issues about CPAP setup need to be clarified. We can only assume that the pressure delivered is close to the water column but cannot be sure about it. We used regular nasal prongs because CPAP nasal prongs are three times costlier (Rs 60 vs. Rs 210). However, regular nasal prongs are available in two sizes, pediatric and neonatal. We use pediatric ones for term babies and neonatal for the preterm. There is a distinct possibility of resistance building up in the circuit and resulting in back flow. We have also not addressed the issue of carbon dioxide retention, especially if the needle in the rubber top to the glass bottle gets clogged. However, wide bore needle that we use may minimize clogging. However, we believe that nasal seal is adequate. Our study has methodological drawbacks too. First, it is not a randomized controlled study, and second, in the pre-cpap group, respiratory distress scoring was performed retrospectively. Most importantly, there is no oxygen/air blender to regulate the fraction of inspired oxygen concentration. The risk of retinopathy of prematurity (ROP) cannot be underestimated. We have started routine screening for babies born at gestational age of 33 weeks. Of the 32 consecutive babies screened so far, 7 babies, all <1300 g, including 2 pairs of twins, have shown aggressive posterior ROP. They have undergone laser therapy at a regional eye care center. Barring small abrasions, we have not come across septal injuries. Thus, we present an affordable and easy-to-use version of CPAP delivery system for the areas where most neonatal deaths occur. 346 Journal of Tropical Pediatrics Vol. 60, No. 5
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