Neonatal n CPAP Apparatus Redesign Mindy Leelawong and

Neonatal n. CPAP Apparatus Redesign Mindy Leelawong and Andrea Holland Advisors: Dr. William Walsh, MD, Professor of Pediatrics, Attending Neonatologist, Chief of Nurseries, Vanderbilt Children’s Hospital Paul King, Ph. D. , Associate Professor Biomedical Engineering Department of Biomedical Engineering, Vanderbilt University, Nashville, TN Introduction • Continuous Positive Airway Pressure (CPAP) breathing apparatus • Assists respiration by forcing air at a pressure ranging from 4 -8 cm. H 2 O • Primarily used for infant respiratory distress Nasal CPAP circuit. The complete CPAP circuit includes three tubes; one each for intake, outtake and measuring the supplied pressure. The outtake tube serves as a noise reduction agent. The tubes converge at the nosepiece that hovers above the nose. The entire apparatus is secured in place with a bonnet. Problem Conclusions and Recommendations • Infants undergoing CPAP for extended periods of time are prone to developing injuries associated with the nosepiece. • Switching between the mask and the prongs will help prolong the time to injury (about every week). • If applicable, give time off between switching of nosepiece types. • Ensure correct nosepiece size. • Position the exhalation tube in bonnet to prevent tilting. • Try the exhalation silencer for the device instead of the accordion tubing. Injuries sustained from extended CPAP use. Septal erosion (A) and nasal snubbing after 60 days of CPAP (B). • Complications o Mask • Septal erosion • Nasal bridge contusion o Prongs • Septal erosion • Nasal flaring • Snubbing 2 o Complication rate • St. George’s Hospital, London 2 ≈ 20% CPAP Administration. Approximately 62% of all underweight infants (≤ 1500 g) underwent CPAP at Columbia University during a one year period. Extremely low weight infants are more like to require intubation before CPAP. Future Recommendations: • More nosepiece sizes • Weight reduction through Generator redesign/modification • Prong/mask shape redesign • Stiffer material for part of mask not touching nose • Different biomaterials for nosepiece Objectives • • Analyze the applied force of the device on the nasal area. Determine the cause of specific injuries. Suggest revisions to current device. Prepare recommendations for proper use of CPAP Methods Testing Results The prongs cause nasal flaring and a small amount of septal erosion. The mask causes septal erosion and some bridge contusions. The weight of the exhalation tube causes the device to tilt, which worsens injuries and causes the seal to loosen. Nosepiece options. EME manufactures two types of nosepieces, a mask and prongs, each with distinct injury characteristics. Alternatives: Literature Review Recommendations to Nurses and Doctors: • Do not over tighten the device to the face. After Before Limitations: • Mathematical Representations: • Difficult to measure the pressure exerted by the device on the nasal area • No measure of Young’s Modulus of neonate skin • Limited literature on the properties of neonate skin • Time Acknowledgements Potential CPAP alternatives. The advantages and disadvantages for several respiratory care methods are outlined. Some alternatives, like the head box and Bloxsom air lock, are not used with regularity. • Interviewed the NICU staff about use, injuries and causes • Made clay model of CPR doll • Tested model on the complete circuit to determine injury We would like to thank the following for their help: Dr. Walsh, Dr. King, Shirley Carpenter, The NICU Staff