1. Efficacy of Non Invasive Biphasic Cuirass Ventilation (BCV) in Neonatal Piglets Comparison with Conventional Positive Pressure Ventilation F.G. Eyal, MD, I. Gur, MD, K.T. O'Donnell, BS and C.R. Hamm Jr. University of South Alabama, Mobile, Alabama, United States and Bikur Holim Hospital, Jerusalem, Israel. We have nothing to Disclose

2. The need for prolonged IPPV despite successful surfactant treatment is a major risk factor for BPD Can NEGATIVE PRESSURE VENTILATION be a successful NON INVASIVE alternative mode of ventilation for newborns at risk for BPD

3. DÉJÀ VU ? 1970 1950 PAST : Effective ventilation of surfactant deficient lungs required levels of inspiratory pressure beyond the capacity of negative pressure respirators incubator PRESENT : Surfactant treatment restores normal lung compliance Continued prolonged ventilatory support relates to poor respiratory drive (apnea of prematurity ) BCV is a modified efficient form of negative pressure ventilation successful in adult and children with respiratory failure due to neuromotor dysfunction

4. HAYEK RTX Respirator Medivent, London HAYEK RTX Respirator Medivent, London

5. Purpose of this study: investigate the efficiency of BCV in an neonatal animal model Can Biphasic Cuirass ventilation successfully ventilated apneic newborn Does the cuirass positive pressure component used during expiration : –Enhanced its efficiency –Can this “mild” compression adversely affect FRC in newborn who have a very compliant chest wall What is the optimal I:E ratio in relation to efficiency Can Biphasic Cuirass ventilation successfully ventilated apneic newborn Does the cuirass positive pressure component used during expiration : –Enhanced its efficiency –Can this “mild” compression adversely affect FRC in newborn who have a very compliant chest wall What is the optimal I:E ratio in relation to efficiency

6. Methods Newborn piglets : 4.7 ±.4 days (2.2 ± 0.1 kg ) (n= 42) Anesthetized & paralyzed Mechanical Ventilation 40 breaths /mn; V T :11 ±.5 ml/kg, Fi0 2 :.4 Newborn piglets : 4.7 ±.4 days (2.2 ± 0.1 kg ) (n= 42) Anesthetized & paralyzed Mechanical Ventilation 40 breaths /mn; V T :11 ±.5 ml/kg, Fi0 2 :.4

7. PaCO 2 PaO 2

8. Ventilatory Efficiency Index (VEI) VEI=3800 * /(respiratory rate x [PIP – PEEP or NCIP-EECP] x PaCO 2 ] * : 3800 is a CO 2 production constant :([ml x mm Hg]/[kg x min])

10. BCV associated to nasal CPAP could be an beneficial alternative to endotracheal IPPV in preterm infants who continue to require mechanical ventilation after surfactant treatment CONCLUSIONS Biphasic Cuirass Ventilation is an effective method of ventilation in neonates Positive expiratory cuirass pressure enhanced its efficiency (in terms of C0 2 elimination) This enables the use of inspiratory pressure of low amplitude (a limiting factor in the past for its efficient use in neonates) The decline in lung volume associated with expiratory positive cuirass pressure is prevented by the concomitant use of CPAP and a cuirass I:E ratio of 2:1

11. PROBLEMS SKIN INTEGRITY THERMOREGULATION PROBLEMS SKIN INTEGRITY THERMOREGULATION