How to troubleshoot low tidal volume on a Hamilton (ventilator) in pediatric patients?

From the Guidelines

To troubleshoot low tidal volume on a Hamilton ventilator in pediatric patients, first check for circuit leaks and verify that the ventilator settings match the prescribed parameters, particularly the tidal volume setting (typically 5-8 mL/kg ideal body weight) as recommended by the 2022 interim guidance to health care providers for basic and advanced cardiac life support in adults, children, and neonates with suspected or confirmed COVID-19 1.

Troubleshooting Steps

• Check for circuit leaks by examining all connections, including the endotracheal tube cuff for proper inflation or repositioning if uncuffed
• Verify that the ventilator settings match the prescribed parameters, particularly the tidal volume setting
• Assess for patient-ventilator asynchrony by observing the patient's breathing pattern and flow-time waveforms
• Check for airway obstruction by listening for breath sounds, suctioning if needed, and examining for tube kinking or secretions
• Evaluate for changes in lung compliance by looking for increased peak pressures or decreased chest movement

Ventilator Settings

• If using pressure-controlled modes, consider increasing the pressure control level by 2-5 cmH2O increments while monitoring peak pressures
• For volume-controlled modes, check if pressure limits are being reached and adjust accordingly
• Ensure the flow rate is appropriate for the patient's size and respiratory demands

Importance of Troubleshooting

These troubleshooting steps are critical because inadequate tidal volume can lead to atelectasis, hypoxemia, and respiratory acidosis, particularly dangerous in pediatric patients who have smaller functional residual capacity and higher metabolic demands than adults, as noted in the evidence based management guideline for the COVID-19 pandemic 1 and pediatric pulmonary hypertension guidelines from the American Heart Association and American Thoracic Society 1.

From the Research

Troubleshooting Low Tidal Volume on Hamilton Ventilator in Pediatric Patients

To troubleshoot low tidal volume on a Hamilton ventilator in pediatric patients, consider the following steps:

• Check the ventilator settings and ensure that the tidal volume is set appropriately for the patient's age and weight 2
• Verify that the endotracheal tube is properly secured and that there are no leaks in the system 3
• Consider using pressure-controlled ventilation, which is commonly used in pediatric patients and can help deliver small tidal volumes accurately 3
• Check the position of the nebulizer in the ventilator circuit, as this can affect aerosol delivery and tidal volume 4, 5
• Ensure that the humidifier is properly set and that the ventilator circuit is heated to the appropriate temperature 4, 5

Factors Affecting Tidal Volume

Several factors can affect tidal volume in pediatric patients, including:

• Type of nebulizer used 4, 5
• Position of the nebulizer in the ventilator circuit 4, 5
• Tidal volume setting 3, 2
• Presence of spontaneous breathing 2
• Type of ventilator used 2

Clinical Judgment and Tidal Volume Selection

Clinical judgment plays a crucial role in selecting the initial tidal volume for pediatric patients 2. Consider the following:

• Visible chest excursion and audible air entry should be used to guide tidal volume selection 2
• The patient's age, type of ventilator, and presence of spontaneous breathing should not be used as the sole criteria for selecting tidal volume 2
• A simple and versatile method of teaching selection of initial mechanical ventilator settings, relying on clinical judgment for regulation of tidal volume, can be effective 2