1) Typical features of neonatal and pediatric lung disease

1. Lower airway disease in children and neonates 1) Typical features of neonatal and pediatric lung disease 2) Pediatric mechanical ventilation: Anything special to know? Conventional vs high frequency ventilation

2. Acute respiratory failure in childhoood pump failure neuromuscular diseases central nervous system disease lung failure primary lung disease (inflammatory) of various etiology IRDS (infant) / ARDS (adult = acute) diffuse atelectasis, permeability oedema low lung compliance, and intrapulmonary shunting (hypoxemia) elevated PaCO2 minimal intrapulmonary shunting easily managed with conventional ventilation settings

3. Typical features of neonatal and pediatric lung disease: • Infant respiratory distress syndrome • Acute hypoxic respiratory failure (incl. ARDS) • Bronchiolitis (RSV-Bronchopneumonia)

4. Clinical characteristics of infant RDS Polypnea resp. freq. > 60 / Min Intercostal Retractions use of accessory muscles Grunting glottis closure at end-expiration Cyanosis intra pulmonary shunting

5. wet lung HMD meconial aspiration congenital pneumonia

6. Preterm infant LUNG IMMATURITY Surfactant deficit ASPHYXIE, SHOCK, ACIDOSIS Neonate at near-term or term

8. Generalized atelectasis, leukocyte infiltration, thick septa, hyaline membranes Normal lung aereation, thin septa

9. Medical developments in the treatment of infant RDS Mortality In the year 2000: Incidence of BPD = 26% < 1500g Lee, Canadian Network, Pediatrics 2000 O2 Mechanical Ventilation Antenatal steroids CPAP Exogeneous Surfactant 1950 1960 1970 1980 1990

10. Treatment-Concept No 1: Lung-Maturation

11. DV C= Reduced pulmonary compliance: D P Normal lung ALI RDS at birth (surfactant depleted lung) Volume (l) severe (A)RDS Airway pressure (cmH2O)

12. Concept No 2: Open the lung and keep it open T --> Surfactant

13. Surfactant as a recruitment agent pre post Volume Pressure PEEP PIP PEEP PIP Kelly E Pediatr Pulmonol 1993;15:225-30

14. Mortality Bronchopulmonary dysplasia Soll RF (Cochrane Database) 2002

15. MRI signal intensity from non-dependent to dependent regions The water burden of the lung makes the lung of the preterm infant, despite surfactant treatment,vulnerable to VILI 2-day-old, 38-week gestation infant 4-day-old, 26-week gestation infant Adams EW AJRCCM 2002; 166:397–402

16. Concept No 2: Open the lung and keep it open T --> Surfactant P --> positive airway pressures: - CPAP - CMV / HFO

17. Pressure limitation + High PEEP VILI prevention: Avoidance of shear, overdistension, cyclic stress and high intrathoracic pressures

18. Acute respiratory failure in childhoood Preterm infant Hyaline membrane disease = infant RDS Lung immaturity Congenital pneumonia acquired lung diseases: nosocomial pneumonia bronchiolitis sepsis Newborn (at term) Congenital pneumonia Meconium aspiration Malformations: Lung hypoplasia, CDH acquired lung diseases: nosocomial pneumonia bronchiolitis sepsis

19. Acute respiratory failure in childhoood Infant (1- 12 months) sepsis-syndrome infectious pneumonia (RSV-bronchiolitis) non infectious pneumonia - inhalational injury circulatory arrest Preschool age sepsis-syndrome infectious pneumonia (RSV-bronchiolitis) non infectious pneumonia - foreign body aspiration - inhalational injury - drowning trauma circulatory arrest

20. Common pathogens for respiratory infections: Neonatal period: group B beta-hemolytic streptococci (GBS) gram negative enteric bacilli (E.coli) Infants and viral (especially RSV) small children: bacterial: Streptococcus pneumoniae mixed infections (e.g., viral-bacterial) can occur in 16-34% of patients

21. Acute viral bronchiolitis Respiratory syncytial virus (RSV) in > 80 % of all cases Parainfluenza I et III, Adenovirus, Rhinovirus Transmission: surface, droplets Variations: seasonal and biannual (?) Primo-infection during the first year of life: 70% At the age of 2 years: 100%.

22. Acute Bronchiolitis: Epidemiology Classical resp. tract infection of the infant (up to 2 years) Hospitalisation required in: 1-3% normal infants 10-25% infants prematurely born Prematurity = single most important risk factor for both hypoxemia and respiratory failure in RSV bronchiolitis 15-25% infants with cardiac malformations 15-45 % infnats with bronchopulmonary dysplasia Prevention: Passiv Immunization Maternal antibodies Monoclonal antibodies: Palivizumab (Synagis) 15mg/Kg im q 1 month

23. Cellular (lymphocytic) infiltration + edema Normal bronchioli

24. PaO2 mmHg PaCO2 mmHg 80 40 50 40 60 F resp 60 80 F resp Bronchiolitis: Physiopathology ~ 4 1/R Edema + infiltration increased resistance + mucus +/- cellular debris Insp. resist. < exp. resist. Insp. retractions Polypnea Exp. wheezing Hyperinflation The child will try to maintain normal minute ventilation · Respiratory fatigue Insuffisance respiratoire Hypercapny (= first warning sign) Hypoxemia occurs later (= vital warning sign)

25. Typical hyperinflation in bronchiolitis

26. Hyperinflation and atelectasis in bronchiolitis

27. Acute Bronchiolitis: Treatment Humidification O2 Surveillance and respiratory monitoring Bronchodilators b-mimetics +/- ipratropium bromide inhaledadrenaline Antiviral therapy Ribavarin - acute effect ?, - longterm benefit + Chest 2002; 122:935-9 Antiinflammatory tx: Steroides - acute phase: shortens length of hospital stay but not duration of ICU-stay or mechanical ventilationThorax 1997; 52:634-7 - not effective on long term outcomePediatr Pulmonol 2000; 30:92-96 CPAP, non-invasive ventilation, intubation + ev. HFO

28. 1) Typical features of neonatal and pediatric lung disease 2) Pediatric mechanical ventilation: Anything special to know? Conventional vs high frequency ventilation

29. From the newborn to the adult: Physiology Chest wall compliance FRC Elastic Recoil Rib cage distortion Pleural pressure distortion

31. From the newborn to the adult: Crs chest wall chest wall Adult Newborn lung lung Agostini J Appl Physiol 1959; 14: 909-913

32. From the newborn to the adult: FRC chest wall chest wall Adult Newborn lung lung Agostini J Appl Physiol 1959; 14: 909-913

33. To maintain a reasonable EELV the neonate closes his glottis at the end of expiration (to avoid lung unit closure) Therefore: An intubated neonate or infant is always ventilated with PEEP

34. From the newborn to the adult: Paw effect chest wall chest wall Adult Newborn EELV above FRC EELV above FRC lung lung Agostini J Appl Physiol 1959; 14: 909-913

35. normal lung compliance decreased lung compliance

36. How much pressure in small children?

37. Adults and children: Acute respiratory distress syndrome (ARDS) Oxygenation Lung volumes Pulm. compliance Mortality: 25 - 35% Mechanical ventilation Newborn: Infant respiratory distress syndrome (iRDS) Ventilator induced lung injury CLD: 15 - 25%

38. Allowable Vt and disease severity ALI Normal lung (surfactant depleted lung) Volume (l) severe (A)RDS Airway pressure (cmH2O)

39. 1) Typical features of neonatal and pediatric lung disease 2) Pediatric mechanical ventilation: Anything special to know? Conventional vs high frequency ventilation

40. CMV CMV HFOV HFOV Rationale for HFOV-based lung protective strategies HFOV uses very small VTs. This allows the use of higher EELVs to achieve greater levels of lung recruitment while avoiding injury from excessive EILV. 2.Respiratory rates with HFOV are much higher than with CV. This allows the maintenance of normal or near-normal PaCO2 levels, even with very small Vts.

41. The concept of volume recruitment during HFO Suzuki H Acta Pediatr Japan 1992; 34:494-500

42. Favors HFO Favors CMV With volume recruitment Elective HFOV vs CMV in preterm infants: Outcome 28 days All trials

43. Survival and CLD Morbidity all patients HFO (n=32) CMV (n=39) p - value survivors to 30 days HFO (n=27) CMV (n=35) Ventilation (days) 5 (3-6) 14 (6-23) 0.0004 * Oxygen dependency (FiO2 > 0.21) (days) 12 (4-17) 51 (20-60) <0.0001 * Oxygen at 28 d, no (%) 6 (22) 22 (63) 0.002 # survivors to 36 weeks PCA HFO (n=27) CMV (n=34) CLD; Oxygen > 36 weeks PCA, no (%) 0 (0) 12 (35) Values are given as the median (95% CI) or the number (percentage) of patients; * Mantel-Cox log-rank; # Fisher's exact First Intention HFO with early lung volume recruitment Retrospective study with historical cohort in preterm infants with RDS, mean GA = 27.7 (± 1.9), < 32 w / mean BW = 970 (± 250), < 1200 g 0.0006 # Rimensberger PC et al. Pediatrics 2000; 105:1202-1208

44. MOAT II: Overall Survival HFOV CV N 75 73 P/F 114 (37) 111 (42) 30d p=0.057 90d p=0.078 HFOV CV Derdak S Am J Respir Crit Care Med 2002; 166:801–808

45. MOAT II: Survival - PIP  38 cmH20 (post-hoc) 30d p=0.019 90d p=0.026 HFOV CV European HFV-Meeting 2001

46. Conclusions Although there exist some special respiratory pathologies in early childhood, treatment concepts are not to much different from the one in adult patients. However, it is important to recognize early signs of respiratory distress in infants and small children, because this patients are at high risk for a sudden cardiac arrest.