In an adult on mechanical ventilation requiring an FiO₂ of 85% for severe hypoxemic respiratory failure, should a tracheostomy be performed now or deferred until the FiO₂ can be reduced?

Tracheostomy Timing in Mechanically Ventilated Patients Requiring High FiO₂

Defer tracheostomy until the FiO₂ requirement decreases below 60% and the patient demonstrates improving respiratory mechanics and gas exchange, as performing the procedure during severe hypoxemic respiratory failure (FiO₂ 85%) carries unacceptable risks of peri-procedural hypoxemia and hemodynamic instability. 1

Rationale for Deferring Tracheostomy

• The 2017 expert consensus on ARDS management explicitly states that "use and timing of tracheostomy should be individualized" and recommends considering tracheostomy only after gas exchange, respiratory mechanics, and hemodynamic status have improved. 1

• An FiO₂ of 85% indicates severe ARDS (PaO₂/FiO₂ likely <150 mmHg), a phase when the patient requires maximal ventilatory support including consideration for prone positioning and neuromuscular blockade—not elective procedures. 1

• The 2024 American Thoracic Society guideline recommends that less invasive therapies (lung-protective ventilation, higher PEEP, neuromuscular blockade, and prone positioning) should be optimized before considering any escalation or procedural intervention. 1

Specific Contraindications at FiO₂ 85%

• Performing tracheostomy during the apneic period required for the procedure will result in critical desaturation when baseline oxygenation is this tenuous, even with apneic oxygenation techniques. 1

• Patients requiring FiO₂ ≥60% typically have PaO₂/FiO₂ ratios <150 mmHg, meeting criteria for severe ARDS where prone positioning (not tracheostomy) is the indicated intervention. 1

• The peri-procedural manipulation, potential bleeding, and temporary loss of PEEP during tracheostomy placement pose life-threatening risks when oxygen reserve is minimal. 1

Safe Timing Criteria for Tracheostomy

Consider tracheostomy only when ALL of the following criteria are met:

• FiO₂ reduced to ≤60% (ideally ≤50%) with stable oxygenation 1
• PEEP ≤10 cmH₂O 1
• PaO₂/FiO₂ ratio >200 mmHg, indicating resolution from severe to mild ARDS 1
• Hemodynamic stability without escalating vasopressor requirements 1
• Improving respiratory system compliance and decreasing ventilatory support needs 1

Management Priorities While Deferring Tracheostomy

Focus on evidence-based ARDS management rather than airway conversion:

• Implement prone positioning for ≥12 hours daily if PaO₂/FiO₂ <150 mmHg—this has a strong mortality benefit and is the priority intervention. 1

• Use neuromuscular blockade if PaO₂/FiO₂ <150 mmHg to optimize ventilator synchrony and reduce oxygen consumption. 1

• Maintain lung-protective ventilation with tidal volumes 4-8 mL/kg predicted body weight and plateau pressure ≤30 cmH₂O. 1, 2

• Optimize PEEP selection based on gas exchange, hemodynamic status, and lung recruitability—consider esophageal pressure measurement to guide PEEP titration. 1

• Consider VV-ECMO if PaO₂/FiO₂ <80 mmHg despite optimal conventional management, rather than proceeding with tracheostomy. 1

Common Pitfalls to Avoid

• Do not perform tracheostomy simply because prolonged mechanical ventilation is anticipated—timing must be based on physiologic stability, not calendar days. 1

• Do not assume tracheostomy will improve oxygenation or ventilation—it is an airway management tool, not a treatment for respiratory failure. 1

• Do not delay prone positioning while waiting for "the right time" for tracheostomy—prone positioning has proven mortality benefit in severe ARDS and should be implemented immediately. 1

• Do not proceed with tracheostomy if the patient requires escalating FiO₂ or PEEP, as this indicates worsening rather than improving respiratory failure. 1

Reassessment Strategy

• Reassess tracheostomy candidacy daily once FiO₂ decreases below 60% and PEEP below 10 cmH₂O. 1

• Monitor for sustained improvement over 24-48 hours before proceeding, as transient improvements may not reflect true stabilization. 1

• If the patient remains on FiO₂ >60% beyond 7-10 days despite optimal ARDS management, consider whether VV-ECMO or palliative care discussions are more appropriate than tracheostomy. 1