Suctioning Artificial Airways: RT Reference Guide

Artificial airways — endotracheal tubes (ETTs) and tracheostomy tubes — bypass the upper airway's natural defense mechanisms, including the cough reflex's effectiveness and mucociliary clearance. Secretions that would normally be cleared by coughing or swallowed now accumulate in the airways, increasing the risk of tube occlusion, atelectasis, ventilator-associated pneumonia (VAP), and respiratory failure.

Suctioning is the primary method for removing secretions from artificial airways. When performed correctly, it maintains airway patency, facilitates gas exchange, prevents VAP, and reduces work of breathing. When performed incorrectly or unnecessarily, it causes mucosal trauma, hypoxemia, cardiovascular instability, and introduces infectious organisms.

The goal is not to suction on a schedule — it is to suction when there is clinical evidence of secretion accumulation requiring removal.

Evidence-based suctioning is indication-driven, not time-driven. Suction when any of the following are present:

• Visible or audible secretions in the airway or circuit
• Coarse breath sounds on auscultation suggesting central airway secretions
• Increased peak inspiratory pressure on volume-controlled ventilation (suggests airway resistance from secretions)
• Decreased tidal volume on pressure-controlled ventilation (same mechanism)
• SpO₂ deterioration without other explanation
• Patient coughing vigorously (secretions present and are reaching the large airways)
• Capnography waveform changes suggesting airway obstruction (upsloping plateau)
• Before and after bronchoscopy, position changes, or transport

Suctioning transiently removes oxygen along with secretions and briefly interrupts ventilation. In patients with marginal oxygenation reserve, this can precipitate rapid desaturation. Pre-oxygenation reduces this risk.

Standard approach: Increase FiO₂ to 1.0 (100%) for 30–60 seconds before suctioning, then return to baseline FiO₂ after suctioning is complete.

Pre-oxygenation may not be necessary in all patients — those who are hemodynamically stable with robust oxygenation reserve and consistently high SpO₂ may not require a FiO₂ increase before every suction pass. Clinical judgment and facility protocol should guide this decision.

For patients on HFOV or patients where circuit disconnection carries significant risk, closed-circuit (in-line) suctioning is preferred to maintain pressure and oxygenation.

Suction catheter size should not exceed half the internal diameter of the artificial airway. Using an oversized catheter obstructs the airway lumen, increases negative pressure transmission to the lungs, and causes greater atelectasis and hypoxemia. Using an undersized catheter may not effectively remove secretions.

Practical guideline: Double the internal diameter of the ETT (in mm), then subtract 2 = maximum catheter size in French (Fr).

Common adult ETT sizes (7.0–9.0 mm ID) typically use 12–14 Fr catheters. Pediatric and neonatal airways require proportionally smaller catheters and more conservative negative pressure settings.

1. 1.Perform hand hygiene and don appropriate PPE.
2. 2.Pre-oxygenate if indicated.
3. 3.Insert the catheter to the appropriate depth — typically just past the end of the ETT (at the carina level, confirmed by a slight resistance or cough). Avoid routine deep suctioning beyond the carina.
4. 4.Apply suction only during withdrawal — not during insertion. Continuous application of suction during insertion increases mucosal trauma.
5. 5.Withdraw steadily with a rotating motion. Each pass should take approximately 10–15 seconds from insertion to withdrawal.
6. 6.Allow the patient to recover between passes — monitor SpO₂ and heart rate. Most patients require 30–60 seconds between suction passes.
7. 7.Limit total number of passes to what is clinically necessary. There is no mandatory number — stop when secretions are cleared.
8. 8.Post-suction assessment: auscultate breath sounds, check SpO₂, assess ventilator graphics, and return FiO₂ to baseline.

VAP bundle compliance is one of the most impactful infection-control practices in the ICU, and suctioning technique is a central component. Key infection control practices:

• Hand hygiene before and after any airway contact.
• Use sterile technique for open suctioning — sterile gloves, sterile catheter, sterile saline if instillation is used.
• For closed systems, rinse the catheter with sterile saline after each use and change the in-line catheter per facility schedule.
• Never reintroduce a contaminated catheter into the airway.
• Maintain head-of-bed elevation at 30–45 degrees (VAP bundle element).
• Oral care with chlorhexidine gluconate as directed by facility protocol (VAP bundle).