10.2 PALICC-2 NIV & Possible PARDS

10.2 PALICC-2 NIV & Possible PARDS

NIV-PARDS

A child on full-face CPAP or bilevel NIV with CPAP of at least 5 cm H2O may meet NIV-PARDS criteria when the timing, risk, imaging, and edema-origin elements are also present. Use PaO2/FiO2 of 300 or less or SpO2/FiO2 of 250 or less for diagnosis.

For NIV-PARDS severity, P/F above 100 or S/F above 150 is mild/moderate; P/F 100 or less or S/F 150 or less is severe. These noninvasive ratios are not interchangeable with OI/OSI because airway pressure is not incorporated the same way.

Possible PARDS on HFNC or an Incomplete Dataset

PALICC-2 recognizes possible PARDS when a patient on nasal respiratory support such as HFNC has the clinical timing, risk factor, imaging, and oxygenation pattern but does not meet the full-face positive-pressure interface requirement. This category promotes recognition and monitoring; it does not justify labeling HFNC as invasive support or calculating OI without an invasively measured mean airway pressure.

An infant must be older than 42 days or have active perinatal lung disease excluded before applying the general PARDS framework. Distinguish acute bronchiolitis without new parenchymal opacities from PARDS triggered by pneumonia or systemic inflammation.

Worked Classification

A ventilated child has MAP 16 cm H2O, FiO2 0.70, and PaO2 68 mmHg. OI = (16 x 0.70 x 100) / 68 = 16.5. If the remaining diagnostic elements are met and the value persists at the severity assessment, this is severe PARDS. The classification increases urgency and monitoring but does not mandate one fixed bundle of rescue therapies.

A child on full-face BiPAP with EPAP 6 cm H2O, new bilateral opacities after pneumonia, and an S/F ratio of 170 may meet mild/moderate NIV-PARDS. A child on HFNC with the same findings is categorized as possible PARDS rather than NIV-PARDS because HFNC is not a full-face CPAP/BiPAP interface.

High-Yield Distinctions

• Use OI/OSI for invasive ventilation and P/F or S/F for noninvasive support.
• Severity is assessed after at least four hours, not from the first isolated blood gas.
• Invasive PALICC-2 categories are mild/moderate versus severe.
• Imaging can be unilateral; bilateral infiltrates are not required.
• Congenital heart disease does not exclude PARDS when an acute oxygenation decline is not explained by the cardiac lesion.

Noninvasive Support Decision Points

NIV classification does not guarantee that NIV is safe. Confirm an intact airway, manageable secretions, adequate mental status, and hemodynamic stability. Fit the full-face interface while protecting skin and minimizing leak, then reassess respiratory effort, synchrony, oxygen requirement, carbon dioxide, and tolerance. Recurrent apnea, shock, worsening encephalopathy, inability to clear secretions, or progressive acidosis favors intubation.

For example, P/F 90 on full-face bilevel support with EPAP 6 cm H2O meets the severe NIV oxygenation band when the other diagnostic elements are present. The same patient on HFNC belongs in possible PARDS because the interface criterion differs. Neither label should delay airway management.

Documentation checklist

Record the precipitating insult and date, imaging finding, reason edema is not primarily hydrostatic, interface, CPAP or EPAP, FiO2, saturation waveform quality, blood-gas time, and calculated P/F or S/F ratio. State whether the child has congenital heart disease, chronic lung disease, or perinatal lung disease and how the acute change differs from baseline. This makes serial classification reproducible across shifts.

Escalation Example

A child on full-face BiPAP has S/F 140, increasing retractions, drowsiness, and rising carbon dioxide. The ratio meets severe NIV-PARDS, but the examination is more urgent than the label: declining airway protection and ventilation favor controlled intubation. Conversely, a stable child with S/F 180, improving effort, and good synchrony may continue a closely monitored NIV trial. Use the classification to standardize communication while bedside physiology determines the intervention.

Interface distinction

Full-face support matters because it can deliver and measure CPAP more reliably than an open nasal high-flow system. Document actual EPAP or CPAP, leak, synchrony, and patient tolerance. A nasal cannula flow rate cannot be converted into a dependable airway pressure, and changing mouth position can alter pressure unpredictably. Therefore, do not relabel HFNC as CPAP or use a guessed MAP to calculate OI. The interface and measured variables determine which PALICC-2 pathway applies.

Reassess frequently. clinically.