8/25/11 Mechanical ven3la3on Neonatal Mechanical Ven3la3on Support oxygen delivery, CO2 elimination" Prevent added injury, decrease ongoing injury" Enhance normal development" Mark C Mammel, MD University of Minnesota Children s Hospital What we need to do" OF MINNESOTA Mechanical ven3la3on Support oxygen delivery, CO2 elimination" Headbox O2" Cannula O2" CPAP ± IMV" Intubation, ventilation" Mechanical ven3la3on Mechanical ven3la3on Prevent added injury" Minimize invasive therapy " Optimize lung volume" Target CO2, O2" Use appropriate adjuncts" Manage fluids and nutrition" Support devices Enhance normal development" Manage fluids and nutrition" Encourage patient-driven support" Maintain pulmonary toilet- carefully" 1
Mechanical ven3la3on Key concepts:" Maintain adequate lung volume" Inspiration: tidal volume" Expiration: End-expiratory lung volume " Support oxygenation and CO 2 removal" Oxygenation: adequate mean airway pressure" CO 2 removal: adequate minute ventilation" Mechanical ven3la3on Key concepts:" Optimize lung mechanical function" Compliance: V/ P" Resistance: Flow/ P" Time constant: C x R" Boros SJ et al: J Pediatr1977; 91:794 Mechanical ven3la3on: How does it work? Patient Patient Inspira3on 2
Mechanical Ven3la3on: Mode classifica3on A. Trigger mechanism What causes the breath to begin? B. Limit variable What regulates gas flow during the breath? C. Cycle mechanism What causes the breath to end? A B C B. Limit Variable C. Cycle Mechanism What causes the breath to end? Pressure A. Pressure limited A. Time Pressure All ven3lators B. Flow Pressure support modes Flow C. Volume Adult / pediatric ven3lators Volume B. Volume limited Volume A B A B C Basic waveforms Time cycle- fixed Ti 3
Flow cycle- variable Ti with limit Mechanical ventilation:" Which vent?" Conventional! Dräger Babylog 8000! Avea! Servo i! High frequency" SensorMedics oscillator" Bunnell HFJV" Conven3onal Ven3la3on Modes:" CPAP" +/- Pressure support (PSV)" IMV/SIMV" +/- Pressure support (PSV), volume targeting" Assist/control (PAC)" +/- volume targeting" Con3nuous posi3ve airway pressure: CPAP Goal:" Support EELV in spontaneously breathing infant (optimize lung mechanics)" Delivery:" NeoPuff, other dedicated CPAP devices" HFNC" Using mechanical ventilator" May be done noninvasively or via ET tube (HFNC in extubated patients only)" Patients:" Newborn infants 26 wks with early distress" Infants in NICU with new distress or apnea" Extubated infants" Con3nuous posi3ve airway pressure: CPAP Setup:" NeoPuff, other dedicated CPAP devices:" Nasal prong interface" Set PEEP (4-6 cm H 2 O most common)" SiPAP: special type of CPAP. Uses 2 levels, usually 2-4 cm H 2 O different" HFNC" Nasal cannula interface" 2-4 L/min flow" Monitoring" CPAP: airway pressure displayed and alarmed" HFNC: none" Early CPAP Columbia Presbyterian" %" * * * * *p<0.0001" 4
Intermi^ent mandatory ven3la3on: IMV/ SIMV Goal:" Support EELV and improve V e in spontaneously breathing infant requiring intubation" Eliminate breath-breath volume variation, cerebral blood flow abnormalities, allow patient control via synchronization of SOME breaths" Delivery:" Using mechanical ventilator" May be done noninvasively or via ET tube" Patients:" Newborn infants requiring intubation" Extubated infants with persistent distress" Intermi^ent Mandatory Ven3la3on: IMV/ SIMV Setup:" ET tube interface" Variables:" Rate- range 15-60 bpm; always synchronized" Volume- target volume 4-7 ml/kg" Pressure- Set peak pressure limit (usually 30 cmh 2 O). Pressure then adjust based on volume. Set PEEP 5-7 cmh 2 O" Time- set at 0.3 0.5 sec based on pt size" Monitoring" Dynamic. Multiple alarm settings. All measured and calculated parameters may be displayed and trended" IMV- unsynchronized Impact of synchroniza3on Assist/control: PAC Goal:" Support EELV and improve V e in apneic or spontaneously breathing infant requiring intubation" Eliminate breath-breath volume variation, cerebral blood flow abnormalities, allow patient control via synchronization of ALL breaths" Delivery:" Using mechanical ventilator" Done via ET tube" Patients:" Newborn infants requiring intubation" Assist/control: PAC Setup:" ET tube interface" Variables:" Rate- set minimum acceptable rate, 40-60 bpm; actual rate depends on patient effort" Volume- target volume 4-7 ml/kg" Pressure- " Peak pressure: Set limit (usually 30 cmh 2 O). Pressure then adjust based on volume. " PEEP: 5-7 cmh 2 O" Time- set maximum at 0.3 0.5 sec based on pt size. Actual varies with lung mechanics. T e varies with rate" Monitoring" Dynamic. Multiple alarm settings. All measured and calculated parameters may be displayed and trended" 5
Assist/control- full synchroniza3on Conven3onal Ven3la3on Variables- What does what?" Minute ventilation (V e ): P a CO 2! V e = RR x V t " V t changes with changing lung mechanics" Tools to change: PIP, PEEP,, T e" Oxygenation: P a O 2, S a O 2! Mean airway pressure (P aw )" Oxygenation varies with lung volume, injury" Tools to change: PIP, PEEP,, T e " Conven3onal Ven3la3on Assessment of V t : PAC (no volume target) Variables- What does what?" Minute ventilation (V e ): P a CO 2! V e = RR x V t " V t changes with changing lung mechanics! Tools to change: PIP, PEEP,, T e! Assessment of V t : PAC, improved C Assessment of V t : PAC + V, imp C- no limit 6
8/25/11 Conven3onal Ven3la3on Conven3onal Ven3la3on Variables- What does what?" Oxygenation: PaO2, SaO2! Mean airway pressure (Paw)" Oxygenation varies with lung volume, injury" Tools to change: PIP, PEEP, Ti, Te! Boros SJ, et al. Pediatrics 74;487:1984 Mammel MC, et al. Clin Chest Med 1996;17:603" Lung Volume Define opening pressure, closing pressure, op3mal pressure: dependent on es3ma3on of lung volume Problems: no useful bedside technology to measure either absolute or change in lung volume Pmax Popt Volume Op3mize lung volume Pcl Pop Lung Volume Pressure Assessment of Paw Ti adjustment Op3mize lung volume SaO2 as volume surrogate Tingay DG et al. Am J Resp Crit Care Med 2006;173:414 7
Assessment of P aw PEEP adjustment Assessment of P aw PIP adjustment Assessment of P aw Rate adjustment RR PIP PEEP Neonatal Mechanical Ventilation: Ventilator setup IMV SIMV A/C PSV 0.2-0.5 sec (flow signal) Set based on Set based on (Vt) 4-10 based on O2 needs, 0.2-0.5 sec (flow signal) Set based on Set based on (Vt) 4-10 based on O2 needs, 0.2-0.5 sec (flow signal) Set lower limit for apnea Set limit; based on Vt 4-10 based on O2 needs, Set limit- 0.3-0.5 sec Set lower limit for apnea Set limit; based on Vt 4-10 based on O2 needs, V t 4-6 ml/kg 4-6 ml/kg 4-6 ml/kg 4-6 ml/kg Flow 3-15 L/min 3-15 L/min 3-15 L/min 3-15 L/min F i O 2 Adjust based on O2 sats Adjust based on O2 sats Adjust based on O2 sats Adjust based on O2 sats Mechanical ven3la3on Mechanical ven3la3on What we know: general" Support affects pulmonary, neurologic outcomes" Greater impact at lower GA" VILI is real" Less is usually more" What we need to know" Who needs support?" Who needs what support?" Risk/benefit for various modalities" When (how) do you wean/stop support?" 8