Mechanical Ventilation: Pediatric Volume Mode (Respiratory Therapy)

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ALERT

Ventilator failure or accidental disconnection can be catastrophic in patients undergoing neuromuscular blockade.

Patients on mechanical ventilation are at high risk for complications like pneumonia, sepsis, acute respiratory distress syndrome (ARDS), and ventilator-induced lung injury (VILI) from volutrauma, barotrauma, or atelectrauma.

OVERVIEW

Volume control ventilation (VCV) delivers breaths triggered by time or patient effort while volume, flow, or time ends the breath. A preset tidal volume (VT) stays constant regardless of changes in resistance or compliance. Airway pressure varies based on factors like peak flow, patient effort, positive end-expiratory pressure (PEEP), compliance, and resistance. A minimum minute volume (MV) is ensured by a preset rate multiplied by the preset VT, and the peak flow determines the breath’s inspiratory time. Some ventilators combine the benefits of volume and pressure ventilation by using a set inspiratory time (TI) to calculate the I:E ratio based on rate and time instead of peak flow and additional pressure limit or pressure max setting for more lung protection. Setting options, terminology, and abbreviations vary by ventilator brand.

Primary modes used include assist control (AC), which delivers breaths with fixed settings while allowing extra spontaneous breaths with the same settings; synchronized intermittent mandatory ventilation (SIMV), which delivers breaths with fixed settings and allows spontaneous breaths in between; and SIMV/pressure support (PS), which delivers breaths with fixed settings and allows spontaneous breaths in between augmented by pressure.

Sensitivity settings determine how easily a patient can trigger spontaneous breaths, using pressure-sensing or flow-triggering mechanisms. Lower cm H₂O or L/min settings increase sensitivity, making it easier for the patient to breathe spontaneously. Sensitivity must be adjusted for each patient to avoid auto-cycling or increased work of breathing.

Peak inspiratory pressure (PIP) is the highest pressure during inspiration. Plateau pressure (Pplat) is the pressure at end-inspiration when gas flow stops. Mean airway pressure (MAP) is the average pressure over the respiratory cycle. Airway pressures vary with the patient’s condition. Decreased compliance stiffens the lungs, increasing Pplat, making it necessary to decrease the VT to maintain safe airway pressures. An increase in rate may be necessary to maintain gas exchange. Lung protective strategies, such as VT (4 to 8 mL/kg) for predicted body weight (PBW),^{undefined#ref1">1,2,5} Pplat less than or equal to 28 cm H₂O,^1,2 and PEEP (Table 1),² are used to reduce the risk of VILI in pediatric patients. PEEP is used to improve or maintain lung volume and improve oxygenation. Auto-PEEP is air trapped in the lungs that cannot be fully exhaled. Auto-PEEP can happen when the exhalation time is not long enough or when lung elasticity and resistance in the airways worsens. A patient-ventilator assessment at regular intervals allows adjustments to ventilator settings for safety, comfort, and synchrony, aiming for mechanical ventilator liberation.²

SUPPLIES

See Supplies tab at the top of the page.

EDUCATION

• Give developmentally and culturally appropriate education based on the desire for knowledge, readiness to learn, preferred learning style, and overall neurologic and psychosocial state.
• Explain the need for mechanical ventilation or setting changes and the alarms to the patient and family.
• Encourage questions and answer them as they arise.

ASSESSMENT AND PREPARATION

Assessment

1. Assess the need for mechanical ventilation or change in ventilator support.^3,5
   1. Apnea
   2. Acute ventilatory failure
   3. Impending ventilatory failure
   4. Severe oxygenation problems (refractory hypoxemia)
2. Assess the patient’s hemodynamic and cardiorespiratory systems.
3. Determine if the patient or family has health literacy needs or requires tools or assistance to effectively communicate. Be sure these needs can be met without compromising safety.
4. Review the patient’s and family’s previous experience and knowledge of mechanical ventilation and understanding of the care to be provided.
5. Find out the patient’s and the family’s desires for the family to be present.

Preparation

1. Gather equipment, including a ventilator with VCV or equivalent option, circuit, humidification device, filters (if needed), manual resuscitation bag, and closed-suction device.
2. Before initiating the mechanical ventilator, check the microprocessor or ventilation system. Perform a short self-test as appropriate.
   1. Verify compliance of the ventilator circuit with the humidification device and filters (if needed).
   2. Document the completed ventilation system test. Include pass or fail, date, initials or signature, and credentials.
3. Verify the authorized practitioner’s order for the initiation of mechanical ventilation or mode of ventilation change.

PROCEDURE

1. Clean hands and put on appropriate personal protective equipment (PPE) based on the risk of exposure to body fluids or infection precautions.
2. Verify the correct patient using two identifiers.
3. Explain the procedure to the family and ensure that they agree to treatment.
4. Select VCV and the mode choice, such as AC, SIMV, or SIMV/PS.

   Setting options, terminology, and abbreviations may be brand specific based on trademarked mechanical ventilator specifications.

5. Set the VT. Begin with 4 to 8 mL/kg for PBW.^1,2,5

   Pplat should not exceed 28 cm H₂O to minimize the risk of VILI.^1,2

6. Set the desired minimum respiratory rate (Table 2).

   The patient may breathe above the set respiratory rate.

   1. An initial rate setting should be based on the patient’s age and size.
   2. Adjust according to arterial partial pressure of carbon dioxide (PaCO₂) and the amount of respiratory support needed.
   3. To encourage spontaneous breathing, choose a lower rate and adjust according to patient comfort and work of breathing.
7. Set the peak flow (L/min) or TI for an I:E ratio greater than 1:2 that allows for a comfortable amount of inhalation and exhalation time (Table 2).⁴
   1. For a patient with a restrictive lung disease, a lower peak flow or higher TI may be needed for a longer inspiratory time.
   2. For a patient with obstructive disease, a higher peak flow or shorter TI may be needed for a longer expiratory time.
8. Select the PEEP.
   1. Begin with 5 cm H₂O (Table 1).⁵
   2. Monitor for auto-PEEP.

      PEEP is titrated up to improve oxygenation, lung function, or lung compliance.

      Increasing I:E ratio or expiratory time may decrease auto-PEEP.

9. Set the trigger sensitivity.
   1. For pressure trigger, start at –0.05 to –1.5 cm H₂O pressure.^3,4
   2. For flow trigger, start at 1 to 2 L/min below baseline flow.^3,4

      Adjust to minimize patient effort and auto-cycling. The lower the number, the easier it is for the patient to trigger the breath.

10. Set the fraction of inspired oxygen (FIO₂).
11. If using SIMV, set the PS level.
    1. Begin with 6 to 10 cm H₂O above PEEP (Table 2).⁵
    2. Adjust to obtain a spontaneous exhaled VT of 4 to 8 mL/kg PBW.
    3. Set additional parameters available for patient comfort and patient-ventilator synchrony, such as slope, rise time, or flow cycle threshold.
12. Set the PIP max or limit, if that option is available.
13. Ensure that all ventilator alarms are on and set appropriately for the patient’s individual ventilator settings.
14. Discard supplies, remove PPE, and clean hands.
15. Document the procedure in the patient’s record.

MONITORING AND CARE

1. Regularly perform a check of ventilator settings, alarms and measured parameters.
2. Maintain the humidification device and circuit temperature (if applicable) to avoid excessive condensation in the ventilator circuit.
3. Assess the patient’s overall level of comfort and patient-ventilator synchrony.
4. To minimize alveolar derecruitment, consider using a closed-suction device to minimize the number of times the patient is disconnected from the ventilator.

EXPECTED OUTCOMES

• Improved oxygenation
• Improved ventilation
• Patient-ventilator synchrony and comfort
• Minimized VILI
• Liberation from mechanical ventilation

UNEXPECTED OUTCOMES

• Alveolar overdistention
• Increased work of breathing
• Worsening oxygenation
• Worsening ventilation
• Ventilator-associated event (VAE)
• Hemodynamic compromise

DOCUMENTATION

• Ventilator settings
  • Mode of ventilation
  • Set VT
  • Set respiratory rate
  • Set peak flow or TI
  • Set PEEP
  • Set trigger sensitivity
  • Set FIO₂
  • Set PS, if applicable
  • Slope, rise time, flow cycle, if applicable
  • PIP max or limit, if option available
• Monitored settings
  • Exhaled VT (mandatory breath)
  • Exhaled VT (spontaneous breath)
  • Minute volume (total)
  • Minute volume (spontaneous)
  • Respiratory rate (total)
  • PIP
  • MAP
  • I:E ratio
  • Auto-PEEP
• Education
• Patient’s tolerance
• Unexpected outcomes and related interventions

REFERENCES

1. Emeriaud, G. and others. (2023). Executive summary of the second international guidelines for the diagnosis and management of pediatric acute respiratory distress syndrome (PALICC-2). Pediatric Critical Care Medicine, 24(2), 143-168. doi:10.1097/PCC.0000000000003147
2. Goodfellow, L.T. and others. (2024). AARC clinical practice guideline: Patient-ventilator assessment. Respiratory Care, 69(8), 1042-1054. doi:10.4187/respcare.12007
3. Shelledy, D.C., Peters, J.I. (2020). Chapter 6: Ventilator initiation. In D.C. Shelledy, J.I. Peters (Eds.), Mechanical ventilation (3rd ed., pp. 311-366). Burlington, MA: Jones & Bartlett Learning.
4. Vines, D.L. (2025). Chapter 49: Initiating and adjusting invasive ventilatory support. In J.K. Stoller and others (Eds.), Egan’s fundamentals of respiratory care (13th ed., pp. 1071-1103. St. Louis: Elsevier.
5. Walsh, B.K. (2023). Chapter 32: Invasive mechanical ventilation of the child. In B.K. Walsh (Ed.), Neonatal and pediatric respiratory care (6th ed., pp. 518-534). Philadelphia: Elsevier.

ADDITIONAL READINGS

Fernández, A. and others. (2023). Invasive ventilatory support in patients with pediatric acute respiratory distress syndrome: From the second pediatric acute lung injury consensus conference. Pediatric Critical Care Medicine, 24(12 Suppl. 1), S61-S75. doi:10.1097/PCC.0000000000003159

Wheeler, C., Smallwood, C.D. (2020). Chapter 15: Neonatal and pediatric critical care. In D.C. Shelledy, J.I. Peters (Eds.), Mechanical ventilation (3rd ed., pp. 601-636). Burlington, MA: Jones & Bartlett Learning.

Clinical Review: Jennifer Elenbaas, MA, BS, RRT, AE-C

Published: March 2025