Pediatric ARDS: Review of consensus recommendations

Nikhil Patankar, MD MBA Pediatric Intensivist, Director for Quality, PICU Beacon Children’s Hospital South Bend, IN What is ARDS? Etiologies Direct Indirect • Bronchiolitis • Sepsis • Pneumonia • Pancreatitis • Aspiration of gastric • Fat embolism contents • Massive blood • Drowning/Submersion transfusion • TRALI • Major trauma • Post obstructive • Anaphylaxis pulmonary edema • Post Lung Transplant • Inhalational injury • Post stem cell transplant • Pulmonary hemorrhage • Pulmonary fibrosis Pathophysiology

• 3 stages: exudative, proliferative, fibrotic • Alveolar inflammation • Surfactant depletion • Capillary leak • Alveolar collapse – Increased physiologic deadspace – Poor oxygen transport Introduction

• First description of respiratory distress syndrome – Asbaugh etal in 1967 – 12 patients with tachypnea, poor lung compliance and hypoxic respiratory failure – Changes similar to neonatal respiratory distress syndrome – Coined the term “Adult” RDS aka ARDS Ashbaugh DG, Bigelow DB, Petty TL, et al: Acute respiratory distress in adults. Lancet 1967; 2:319–323 Evolution

• American-European Consensus Conference in 1994 – Renamed it “Acute” RDS – AECC criteria – Acute onset – Severe hypoxemia (PaO2/FiO2<200) – Bilateral opacities on chest X-ray – Absence of left ventricular failure, confirmed by clinical examination or right heart catheterization (PCWP <18 mmHg). Berlin definition Need for pediatric definition

• Berlin definition did not take children into consideration • Need for PaO2 – Will miss kids with only Spo2 measurements • PEEP of 5 – Wide range of NIV/Invasive ventilation use in PICUs • Outcomes not considered • Difference in risk factors, etiology, and pathophysiology PALICC

• Pediatric Acute Lung Injury Consensus Conference • PALISI • Australia and NZ Intensive Care Society • Canadian Critical Care Trials Group • World Federation of Pediatric Intensive • and Critical Care Societies • European Society for Pediatric and • Neonatal Intensive Care • French Group for Pediatric Intensive Care and Emergency Medicine Goals

• Develop a taxonomy to define pediatric ARDS (PARDS) – Specifically predisposing factors, etiology, and pathophysiology • Offer recommendations regarding therapeutic support • Identify priorities for future research – defining short- and long-term outcomes Differences from Berlin definition

• The PALICC definition does not require bilateral infiltrates on CXR • Introduces use of pulse oximetry and provides criteria for SpO2:FiO2 when PaO2:FiO2 is unavailable • Introduces use of oxygenation index (OI) or oxygenation-saturation index (OSI) to stratify severity groups instead of PF ratio with minimum Positive End Expiratory Pressure (PEEP) • Specific criteria to define PARDS in children with chronic lung disease and cyanotic heart disease • Identifies a group of patients felt to be at risk for PARDS

Age, timing, LV dysfunction

• Age: should not be criteria for definition – Exclude perinatal related lung disease (S)

• Timing and trigger: Hypoxemia and chest x- ray findings within 7 days of insult (S)

• Acute LV dysfunction: ARDS criteria not explained by LV dysfunction (S) Radiography

• New infiltrate needed for diagnosis (S)

• Future studies needed to determine effect of “automated methodologies to reduce interobserver variability” (S) Oxygenation

• Measures: Use OI instead of PF ratios (S) – PF ratio for NIV with minimum CPAP of 5 (S) • Elevation of deadspace ventilation needs future studies (S) • Measures of respiratory system compliance should not be used (S) • When using Spo2, titrate oxygen between 88-97% (97 is new 100) (S) CLD and cyanotic CHD

• If acute changes, can be said to have PARDS (S)

• Do not use OI or OSI to stratify PARDS in this subset (S) Severity of Illness/Outcomes

• Onset, within 24 hr. and thereafter (S) • Dead space in adults related to outcomes; need future pediatric studies (S) • Tidal volume, PEEP, mean airway pressure: need future studies (S) • MSOF estimate should be included in future studies (S) • Look at clinically relevant outcomes (S) Conventional ventilatory support

• Low tidal volumes (5 ml/kg) (W-88%)

• Adjust Vt for resp compliance (W-84%) • Limit plateau pressure to 28 (29-32 in patients with stiffer lungs) (W- 72%) • High PEEP (10-15) (W-88%) • >15 PEEP may be needed for severe ARDS (S) • Monitor makers of DO2, resp system compliance, hemodynamics with elevated PEEP (S) High Frequency ventilation

• HFOV: Use in severe ARDS, especially with plateau pressures >29 (W-92%) • HFOV: Stepwise increase or decrease in mean airway pressure to achieve optimal lung volume with response to hemodynamics (S) • Cannot recommend routine use of HFJV (S) Ventilation

• Use cuffed ETT (S) • Leak around ETT on HFOV (S) • Mild ARDS: PEEP <10 ; goal saturations 92-97% (W-92%) • When SPo2 <92%, markers of DO2 should be monitored (S) • Permissive hypercapnia to minimize VILI (S) • pH goals 7.15-7.3 (W-92%) • Routine use of HCO3 not recommended (S) Pulmonary specific ancillary treatment • iNO: routine use not recommended (S) – Except: Pulm HTN, RV dys, bridge to ECMO • Surfactant: not recommended (S) • Prone positioning: No routinely recommended, can be used in severe PARDS (W-92%) • Suctioning- helpful, avoid decruitment (S) • Saline: No routine use, for thick secretions (S) • Chest PT: not routinely recommended (S) • Steroids : Not routinely recommended (S) Sedation and NMB

• Minimal and effective target sedation (S) • Sedation scales (S) • Objective withdrawal scoring and assessment (S) • When sedation alone not effective, use NMD (S) • Train of four, daily paralytic holidays (S) Nutrition/ Fluids/PRBC • Nutrition plan (S) • EN over PN (S), early EN preferred • Goal directed protocol (S) • Goal directed fluid management, with aim to prevent positive fluid balance (S) • Consider PRBC Tx only when Hb <7.0 gm/dl (S) – Except: cyanotic CHD, bleeding, severe hypoxemia Monitoring

• Specific alarms (S) • Measuring weight (S) • ETCO2 and Transcutaneous CO2(S) • Measure inspiratory pressures (S) • Peripheral blood venous gas sampling not recommended (W-83%) Weaning/Imaging

• Spontaneous breathing trials (S) • Extubation readiness assessment (S) • No evidence to use CT, Lung US routinely (S) • Frequency of CXR should be base don patient’s clinical status (S) Hemodynamics

• ECHO for RV or LV dysfunction (S)

• Peripheral arterial catheter in severe PARDS (S)

• Not enough evidence to recommend routine BNP and ScVO2 monitoring (S) Non invasive ventilation (NIV)

• NIV should be delivered in a setting with trained and experienced staff (S) • Consider IPPV if no clinical improvement (S) • HFNC has not shown to be equivalent to NPPV (S) • Use heated humidification(S) • Sedation should be used with caution (W- 88%) ECMO

• When all standard measures fail (S) • If resp etiology is reversible and patient suitable for lung transplantation (S) • Assess quality of life pre ECMO (S) Outcomes to be measured

• 90 day mortality • New or progressive organ dysfunction, organ failure • Treatment free/ ventilator-free days • Duration of oxygen use/change from baseline • Risk-adjusted hospital and PICU lengths of stay • Hospital and PICU readmission rates • Quality of life, neurocognitive function, and emotional health

References

• The Pediatric Acute Lung Injury Consensus Conference Group, Pediatric Acute Respiratory Distress Syndrome: Consensus recommendations From the Pediatric Acute Lung Injury Consensus Conference, Pediatr Crit Care Med 2015; 16:428–439

• The ARDS definition task force, Acute Respiratory Distress Syndrome: The Berlin Definition, JAMA. 2012;307(23):2526-2533 QUESTIONS?