ICU PROCEDURES: MECHANICAL VENTILATION

by | Sep 12, 2024 | Nurse Article | 0 comments

ICU Procedures: Ventilator Setup and Monitoring and Weaning Protocols

Ventilator setup, monitoring, and weaning protocols are essential procedures in the Intensive Care Unit (ICU) to manage patients who require mechanical ventilation due to respiratory failure, surgery, or severe illness. Here’s a detailed breakdown of each procedure:

1. Ventilator Setup and Monitoring

Ventilator Setup involves configuring the ventilator machine to support or take over a patient’s breathing. Settings are adjusted based on the patient’s condition and the type of ventilation needed (e.g., volume-controlled, pressure-controlled).

Procedure for Ventilator Setup:

  1. Preparation:
    • Review the patient’s medical history, diagnosis, and clinical status.
    • Confirm the size and type of endotracheal tube or tracheostomy tube in use.
  2. Select Ventilation Mode:
    • Volume-Controlled Ventilation (VCV): Delivers a preset tidal volume.
    • Pressure-Controlled Ventilation (PCV): Delivers breaths at a preset pressure.
    • Assist-Control Ventilation (AC): Provides a set number of breaths per minute and assists if the patient initiates a breath.
    • Synchronized Intermittent Mandatory Ventilation (SIMV): Allows spontaneous breathing between mandatory breaths.
    • Positive End-Expiratory Pressure (PEEP): Helps keep alveoli open to improve oxygenation.
    • Continuous Positive Airway Pressure (CPAP): Used for spontaneous breathing patients to keep airways open.
  3. Set Ventilator Parameters:
    • Tidal Volume (Vt): Typically set to 6–8 mL/kg of ideal body weight.
    • Respiratory Rate (RR): Set based on the patient’s condition, often between 12–20 breaths per minute.
    • FiO2 (Fraction of Inspired Oxygen): Adjusted to maintain adequate oxygenation (typically starting at 100% and then titrated down).
    • PEEP: Usually set between 5–10 cm H₂O to keep alveoli open and prevent collapse.
    • Inspiratory Time (I-time): Adjusted to control the duration of inhalation.
  4. Connection to Patient:
    • Attach the ventilator circuit to the patient’s endotracheal or tracheostomy tube.
    • Secure the tube to prevent dislodgement.
  5. Alarms Setup:
    • Set ventilator alarms for pressure, volume, and rate to alert the healthcare team of issues such as airway obstruction, leaks, or high/low pressures.
  6. Final Checks:
    • Confirm that the ventilator is functioning correctly by observing chest rise, auscultating breath sounds, and reviewing the initial blood gas readings.
    • Monitor for leaks around the cuff by measuring cuff pressure (typically between 20–30 cm H₂O).

Monitoring the Patient on Mechanical Ventilation:

  1. Ventilator Settings:
    • Continuously assess the ventilator settings and make adjustments based on arterial blood gas (ABG) analysis, oxygen saturation (SpO2), and end-tidal CO2 (EtCO2) monitoring.
  2. Patient’s Respiratory Status:
    • Oxygenation: Monitor SpO2 and FiO2 to ensure adequate oxygen delivery.
    • Ventilation: Check the patient’s tidal volume, minute ventilation, and respiratory rate.
    • Lung Mechanics: Evaluate compliance and resistance (e.g., plateau pressure and peak airway pressure).
  3. Hemodynamic Monitoring:
    • Watch for changes in blood pressure and heart rate, which can be affected by ventilator settings (especially PEEP).
  4. Ventilator Alarms:
    • Respond promptly to ventilator alarms such as high/low pressure, disconnection, or low tidal volume alarms. Investigate the cause and adjust settings or troubleshoot the problem.
  5. Sedation and Comfort:
    • Monitor the patient’s comfort and level of sedation using a sedation scale. Ensure that the patient is not fighting the ventilator, which may require adjustments in sedation, ventilator mode, or settings.

2. Weaning Protocols

Weaning from mechanical ventilation is the process of gradually reducing ventilator support as the patient’s respiratory function improves, eventually leading to the patient breathing independently.

Procedure for Weaning:

  1. Assessment for Readiness to Wean:
    • Ensure the underlying cause of respiratory failure is resolving or resolved.
    • Clinical Criteria:
      • Hemodynamically stable with minimal or no vasopressor support.
      • Adequate oxygenation (FiO2 ≤ 0.4, PEEP ≤ 5–8 cm H₂O, SpO2 ≥ 90%).
      • Stable ABGs (PaO2/FiO2 ratio > 200).
      • Improved mental status, with the ability to follow commands.
      • No signs of active infection or metabolic disturbances.
  2. Spontaneous Breathing Trial (SBT):
    • The most common method of assessing readiness for weaning.
    • Discontinue sedation, allowing the patient to breathe spontaneously through the ventilator’s CPAP or T-piece.
    • Duration: SBTs typically last 30–120 minutes.
    During the SBT, monitor:
    • Respiratory rate (should be < 35 breaths per minute).
    • Oxygen saturation (SpO2 should remain ≥ 90%).
    • Heart rate (should remain stable).
    • Signs of fatigue or respiratory distress (increased work of breathing, use of accessory muscles).
  3. Gradual Ventilator Support Reduction:
    • If the patient fails the SBT, gradual reduction in support may be needed:
      • SIMV Mode: Reduce the mandatory breaths and allow more spontaneous breathing.
      • Pressure Support Ventilation (PSV): Decrease the level of pressure support provided.
  4. Extubation:
    • Once the patient successfully passes the SBT and shows readiness for extubation:
      1. Pre-Extubation Preparation:
        • Ensure the patient has a strong cough and gag reflex to protect the airway.
        • Suction the airway to remove secretions.
      2. Remove the Endotracheal Tube:
        • Deflate the cuff and remove the tube while the patient is instructed to cough.
      3. Post-Extubation Monitoring:
        • Closely monitor the patient for signs of respiratory distress, airway obstruction, or aspiration.
        • Apply supplemental oxygen if needed.
        • Monitor ABGs and respiratory status for the first few hours post-extubation.

Nursing Considerations During Weaning:

  • Frequent assessment of the patient’s respiratory function and readiness for weaning.
  • Monitoring for fatigue, dyspnea, and anxiety during weaning trials.
  • Communicating with the medical team to adjust weaning protocols as necessary.
  • Providing psychological support to the patient during weaning, as it can be a stressful experience.

Summary

Effective ventilator setup and monitoring ensures that patients receive appropriate respiratory support while minimizing complications. Weaning protocols help guide the safe transition of patients off mechanical ventilation, promoting recovery while reducing the risk of prolonged intubation. Close observation, timely interventions, and patient-centered care are vital throughout both processes.