| Key principles |
Minimizing VILI: Therapeutic strategies to support gas exchange while minimizing VILI include: - Avoidance of MV through preferential use of nCPAP when possible
- For neonates who fail nCPAP and require invasive MV, lung protective strategies include:
- Preferential use of VTV with Tv of 4 to 6 mL/kg to minimize volutrauma
- Use of PEEP to maintain lung recruitment and avoid atelectasis
- Avoidance of high FiO2
- Setting targets for gas exchange that do not aim for normal levels (ie, modest permissive hypercapnia)
- Use of HFOV or HFJV in neonates at high risk of developing VILI or as rescue therapy for neonates with refractory respiratory failure while on CMV
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Achieving gas exchange: With CMV, the primary means of achieving ventilation (CO2 clearance) and oxygenation (uptake of O2) are as follows: - Ventilation – CO2 clearance is primarily determined by minute ventilation (ie, RR and Tv).
- Oxygenation – Oxygenation is primarily determined by MAP and FiO2. In CMV, MAP is largely determined by PEEP.
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| Indications for MV |
If, despite efforts to optimize noninvasive support, the neonate develops any of the following signs of inadequate gas exchange, we typically intubate and initiate invasive MV*: - pH <7.20, with PaCO2 >65 mmHg
- Requiring FiO2 >0.4 to 0.5 to achieve target SpO2 goal
- Multiple apneic episodes per hour associated with desaturations and bradycardia or more than 1 episode requiring positive pressure ventilation within a few hours
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| Initial mode and settings |
| The ventilator mode and settings must be tailored to meet the needs of the individual neonate, which may differ between patients and within the same patient over time. In our center, we typically initiate MV with CMV and reserve HFV for cases of refractory respiratory failure despite efforts to optimize CMV. However, other centers may use HFV as an initial ventilation strategy in neonates at high risk for developing VILI. |
Mode: - We typically use a synchronized mode with both mandatory and spontaneous breaths (ie, SIMV + PS or ACV)
- We preferentially use VTV in all preterm neonates
- We use PLV if there is a technical challenge that limits the reliable delivery of measured Tv (eg, large ETT leak) or VTV is not available
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Initial settings: - Tv 4 to 6 mL/kg
- PEEP 5 to 6 cm H2O
- Ti 0.35 to 0.4 seconds
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| Monitoring |
Appropriate monitoring includes: - Continuous SpO2 monitoring
- Serial assessments of work of breathing
- Blood gases¶ – CBG and VBG are adequate in many cases, but placement of an arterial catheter for ABG sampling may be warranted in some cases (if the neonate is requiring blood sampling more frequently than every 6 hours or has hemodynamic instability requiring active titration of vasoactive medications)
- Ventilator monitoring, including PIP and exhaled Tv measured by the ventilator
- Chest radiographs – Chest radiographs should be obtained judiciously to inform decisions about ventilator settings and/or identify acute changes (eg, air leak, malpositioned ETT)
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| Gas exchange targets |
| Oxygen target: SpO2 target 90 to 95% |
Carbon dioxide targets: - For most preterm neonates in the first few weeks of life: pCO2 target is between 40 and 65 mmHg (ie, modest permissive hypercapnia)
- For older preterm infants with evolving BPD, it is reasonable to use more liberally permissive pCO2 targets as long as the pH remains >7.25
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