Minimizing Lung Damage During Respiratory Support

Transcription

1 Minimizing Lung Damage During Respiratory Support University of Miami Jackson Memorial Medical Center Care of the Sick Newborn 15 Eduardo Bancalari MD University of Miami Miller School of Medicine Jackson Memorial Hospital % Bronchopulmonary Dysplasia (O 2 at 36 wks PMA) Years NICHD NETWORK Gestational Age (wks) What Can Damage The Immature Lung Over distension Excessive V T : PIP PEEP Excessive FRC: PEEP, gas trapping Prolonged inspiratory time Low volume, loss of FRC: Insufficient PEEP Oxidative damage Infection: Pulmonary, systemic Increased PBF-PE : PDA, excessive fluid administration Inadequate conditioning of the inspired gas: Temperature, humidity How Can We Protect The Immature Lung? Accelerate Maturation: Antenatal steroids Surfactant Replacement Prophylaxis vs Rescue? Gentle Ventilation Appropriate tidal volume / Volume target/ HFV Adequate PEEP Patient Triggered Ventilation Permissive hypercapnia? Avoid High Inspired Oxygen Concentrations Avoid Invasive Ventilation: CPAP, N-IPPV Respiratory support strategies to prevent BPD Respiratory support during resuscitation : Ventilation, Oxygen NCPAP vs intubation after birth NIPPV vs IPPV in RDS Synchronized ventilation Permissive hypercapnia HFV: HFO, HFJV Volume targeting Oxygen targets 1

2 % Infants in respiratory care groups Does variation in respiratory management in NICUs explain differences in CLD? Van Marter. Pediatrics, 15, Do differences in delivery room intubation explain different rates of BPD between hospitals? Compared Columbia NY with 2 Boston hospitals. Infants < 151g in Boston Columbia n=341 n=1 Ventilation 75% 29% Surfactant 45% 1% Oxygen at 36 wks 22% 4% IPPV >24h = OR for BPD 2.4 IPPV >7d = OR for BPD 14.9 Gagliardi, L et al. Arch Child Fetal Neonatal Ed. 11;96:F3-F35 NCPAP vs. IPPV BPD or Death Early CPAP vs. IPPV in extremely low gestational age newborns Death/BPD IPPV Surfactant CPAP MV-Surf CPAP MV-Surf CPAP MV-Surf COIN wks 34% 39% 58.7% 1% 38% 77% SUPPORT wks 49% 54% 83.1% 24.8 d 99.7% 27.7d 67% 99% VON (CPAP) 26-3 wks 31% 37% 52% 96% 46% 99% VON (ISX) 29% 37% 59% 96% 98% 99% Fischer S H, and Buhrer C, Pediatrics Nov Distribution of infants (%) into respiratory care groups by birth weights CPAP-started (% of total) CPAP-success (% of CPAP-started) CPAP-success (% of total) Is Nasal Ventilation a Better Alternative? <125 Possible mechanisms of action: Increase in Vt and Ve Upper airway stimulation may reduce apnea Higher mean airway pressure: Better lung stability and gas exchange Reduced dead space: Clears exhaled gas from proximal airway Birth weight (g) Adapted from Ammari et al. J Pediatr. 5; 147(3):

3 Ventilator Dependence Nasal Ventilation Physiologic effects Decreases apnea Improves ventilation- gas exchange Increases lung volume- improves oxygenation Decreases respiratory effort Decreases chest wall distortion Non Invasive Respiratory Support - Conclusions Many very premature infants can be managed with NCPAP or NIPPV from birth It is difficult to predict which infants will fail and require intubation and mechanical ventilation Success depends on gestational age, degree of lung disease, respiratory drive, and team s attitude and skills Use of NIPPV instead of CPAP may reduce the number of infants that need intubation and shortens the duration of MV Early NCPAP or NIPPV may delay administration of surfactant in infants with RDS and worsen their evolution The evidence that non invasive respiratory support improves short or long term outcome in ELBW infants is not very compeling Approach to VLBWI in the DR Depressed - Poor resp effort ET tube IPPV Surfactant if RDS When stable extubate to NCPAP or N-IMV Deterioration, Increasing FiO2, PaCO2, Apnea ET tube-ippv- Surfactant if RDS When stable extubate to NCPAP or N-IMV Active - Good resp effort Start NCPAP or N-IMV Stable-Continue NCPAP Newer Modalities of Mechanical Ventilation Patient Triggered (Synchronized Ventilation) S-IMV Assist control Pressure support Proportional assist ventilation (PAV) NAVA (Neurally adjusted ventilatory assist) Volume targeted ventilation Experimental: Closed Loop FiO 2 control Continuous flow or distal tracheal ventilation Targeted minute ventilation CONTROLLED IPPV (Apnea or M. Relaxants) ASSISTED VENTILATION IMV - SIMV - AC - PSV - PAV Synchronized vs. Conventional Ventilation Duration of ventilation NON INVASIVE SUPPORT Nasal CPAP - Nasal IPPV Greenough and Dimitriou Cochrane Database 8 3

4 IMV vs. SIMV and Hypoxemia in Preterm Infants cmh 2O SIMV ( b/m) P aw 16 ml V T cmh 2O.8 s SIMV (1 b/m) + PS P aw 16 ml V T Firme SRE et al. Pediatr Pulmonol 5;(1):9-14 Time to extubation 1 SIMV+PS SIMV Ventilator and Oxygen Dependency 7-1g BW strata SIMV SIMV+PS Ventilator Dependency (%) 8 6 On MV at day 28 SIMV 69% SIMV+PS 47% Days on MV (median, 25 th and 75 th percentile) Days on oxygen (median, 25 th and 75 th percentile) 25 (8-47) 15 (6-23) 58 (44-87) 41 (34-51)* Time (Days) Reyes et al. Pediatrics October 6 On oxygen at 36w PMA Reyes et al. Pediatrics October % *P.34 Pressure Support Ventilation Patient maintains spontaneous respiratory effort Duration of inspiration and expiration determined by the patient Spontaneous breaths can be unloaded as necessary to maintain Vt and Ve Volume loss can be prevented by few larger SIMV breaths Weaning is accomplished by gradual reduction of the pressure support Limitations of PTV Low Sensitivity of trigger Lack of trigger Trigger delay: Mechanical breath extending into expiration causing active expiration Excessive sensitivity to trigger artifacts: Auto triggering Early termination, mechanical inspiration too short: insufficient tidal volume Added dead space:co2 retention 4

5 Volume Targeted Ventilation Volume-targeted vs. pressure limited ventilation: Duration of IPPV VTV versus PLV: Death or BPD (36 weeks) Duration of IPPV (log data) No. of studies No. of Infants Statistical method Mean Difference (IV, Fixed, 95% CI) Effect size -.8 [-.16, -.] Wheeler K et al. Cochrane Database of Systematic Reviews 1, Issue 11. Significant difference Death or BPD 32% v 43% RR.73 95% CI.57 to.93, NNT 8 Wheeler K et al Neonatology 11 VTV versus PLV: Pneumothorax VTV versus PLV: Grade 3/4 IVH or PVL Pneumothorax Significant 4% difference v 1% RR.46, 95% CI Wheeler K et al Neonatology 11 PVL or grade 3-4 IVH 8% v 16% RR.48, 95% Significant CI.28 - difference.84 Wheeler K et al Neonatology 11 5

6 Volume-targeted ventilation is more suitable than pressure-limited ventilation for preterm infants: a systematic review and meta-analysis BPD VG Peng WS et al. Arch Dis Child Fetal Neonatal Ed 13;:F1 F8. doi:1.1136/archdischild Volume targeted ventilation Rationale: More consistent Vt avoids excessive volumes Automatic weaning of pressure Shorter duration of mechanical ventilation Reduces duration of hypoxemia episodes Reduces death or BPD Limitations: Leaks around the endotracheal tube Poor estimation of Vt: Different inspiratory and expiratory Vt with leaks Volume loss in the ventilator circuit: Vt delivered by ventilator larger than patient Vt Cools F, Henderson-Smart DJ. Cochrane Database of Systematic Reviews 9 Hyperoxia Disrupts Alveolar Development Room air O 2 OXYGEN DAMAGE Contrasting light microphotographs of lung parenchyma of rats exposed to room air and O 2 Shaffer SG, et al. Pediatr Res. 1987;21:14-. 6

7 Incidence (%) TEN YEAR TRENDS IN NEONATAL ASSISTED VENTILATION Are New Ventilation Modalities Associated With Better Outcome? Rich W, et al: Journal of Perinatology 3, 23:66 Unadjusted annual rates for GA <29 weeks (n = 1441) 39 th Annual International Conference BPD Severe BPD Miami Neonatology 15 & Workshop: Advances in Neonatal Respiratory Care November 11 November 14, 15 Fontainebleau, Miami Beach Year Smith et al. J Pediatr. April 5; 146(4): Speakers Topics Thrombocytopenia in the NICU Robert Bob Christensen, MD Evidence-based NICU transfusion guidelines Growing extremely premature infants in the NICU Scott C. Denne, MD Providing enteral nutrition to extremely premature Terrie Eleanor Inder, MD, M.B.CH.B. Influence of the environment and experience on brain development To MRI or not to MRI at term for the preterm infant Julie R. Ingelfinger, MD Acute kidney injury (AKI) in the neonatal period Shahab Noori, MD, RDCS The neonate with CAKUT Diagnosis and Management of Neonatal Hypotension and Shock Saroj Saigal, MD, FRCP Pathophysiology of P/IVH in the very preterm neonate Pablo Sanchez, MD Lifetime perspectives of former very premature infants Quality of life of former premature infants Umberto Simeoni, MD Antimicrobial Stewardship in NICU Sergio Stagno, MD Early nutrition and the risk for long term disease Extreme preterm birth and medical decision making Anton H van Kaam, MD, PhD Perinatal viral infections, new developments on an old challenge Myra Wyckoff, MD High frequency ventilation Lung protective ventilation using conventional modes Jill L. Maron, MD, MPH 15 New Neonatal Resuscitation Guidelines Use of monitoring and Epinephrine in the DR 7