Guide — Respiratory
Mechanical Ventilation Basics for Nurses
Mechanical ventilation supports or replaces the patient's breathing when they cannot maintain adequate ventilation or oxygenation independently. Understanding the purpose, indications, and key settings is essential for safe nursing monitoring.
11 min read · Respiratory
Educational use only. Ventilator management requires provider and respiratory therapy orders and clinical expertise. Nurses monitor and respond to alarms but do not independently adjust ventilator settings without orders. This guide supports learning, not autonomous practice. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
Purpose of Mechanical Ventilation
Mechanical ventilation is used when a patient's respiratory system can no longer sustain adequate gas exchange. It serves two primary goals:
Indications for Mechanical Ventilation
| Category | Examples |
|---|---|
| Respiratory failure | ARDS, severe pneumonia, pulmonary edema — unable to maintain SpO₂ ≥90% on maximal non-invasive support |
| Ventilatory failure | COPD exacerbation with CO₂ retention, neuromuscular disease (Guillain-Barré, ALS), opioid overdose with respiratory depression |
| Airway protection | Decreased LOC (GCS ≤8), massive hemoptysis, aspiration risk from altered mental status |
| Post-operative support | After major cardiac, thoracic, or neurological surgery — until the patient is awake and stable enough to maintain their own airway |
| Hemodynamic instability | Severe shock — mechanical ventilation reduces respiratory muscle oxygen consumption and work of breathing |
Key Ventilator Settings
Nurses must understand what each ventilator setting controls, what changes in the setting mean clinically, and what findings should prompt provider notification.
Controls the percentage of oxygen delivered with each breath. Room air = 21%. The goal is the lowest FiO₂ that maintains SpO₂ ≥94% (88–92% in COPD/hypercapnic patients). High FiO₂ over time causes oxygen toxicity — pulmonary injury from reactive oxygen species.
Clinical pearl: FiO₂ >60% for prolonged periods → oxygen toxicity risk. Always titrate to the lowest effective level.
Maintains positive pressure at end-exhalation to prevent alveolar collapse (atelectasis). Recruits collapsed alveoli, improves V/Q matching, and improves oxygenation. Standard is 5 cmH₂O. Higher PEEP is used in ARDS (up to 15–20) to maintain alveolar recruitment.
Clinical pearl: High PEEP can reduce venous return → decreased cardiac output → hypotension. Monitor BP closely after PEEP changes.
Volume of air delivered with each breath. Low tidal volume (6 mL/kg IBW) is the standard in ARDS — the ARDSNet protocol. High tidal volumes cause volutrauma (overdistension) and worsen lung injury. Calculated based on ideal body weight, not actual weight.
Clinical pearl: Use ideal body weight for Vt calculation — using actual weight in obese patients causes overventilation and lung injury.
Number of mandatory breaths delivered per minute by the ventilator. Controls minute ventilation (RR × Vt) and thus CO₂ removal. Increasing RR lowers PaCO₂; decreasing RR raises PaCO₂.
Clinical pearl: High RR → risk of breath stacking (auto-PEEP) especially in obstructive disease — allow adequate expiratory time.
PIP is the highest pressure during delivery of the breath — reflects airway resistance. Plateau pressure is the pressure after flow stops, reflecting alveolar (lung) compliance. High plateau pressure (>30) indicates poor compliance — classic in ARDS, tension pneumothorax, or worsening pulmonary edema.
Clinical pearl: Sudden increase in PIP = secretions, bronchospasm, kink, or pneumothorax. Gradual increase in plateau = worsening compliance (ARDS progression).
Nursing Monitoring Priorities
| What to Monitor | Why / What to Report |
|---|---|
| SpO₂ and ABG values | Primary oxygenation and ventilation indicators; notify provider if SpO₂ <90% or ABG outside target parameters |
| Ventilator settings match orders | Verify mode, RR, Vt, PEEP, and FiO₂ match the current ventilator order at each assessment |
| Peak and plateau pressures | Sudden PIP increase → suction, reposition, or DOPE evaluation; plateau >30 → notify provider |
| Breath sounds bilaterally | Unilateral absent sounds may indicate right mainstem intubation, pneumothorax, or effusion |
| ETT position and cuff pressure | Confirm ETT depth at lips q4–8h; cuff pressure target 20–30 cmH₂O to prevent aspiration and tracheal injury |
| Sedation and pain (RASS/SAS, CPOT) | Over-sedation prolongs ventilation; under-sedation → dyssynchrony, self-extubation risk, ETT biting |
| VAP prevention bundle | HOB 30–45°, oral care q4h, daily sedation vacation, spontaneous breathing trial readiness |
| Hemodynamics | PEEP reduces venous return; patients may need fluid adjustment after PEEP increases — monitor BP and HR |
NCLEX Pearls
- ›Assess the patient first when a vent alarm sounds — then troubleshoot the machine.
- ›If you cannot quickly identify the cause of deterioration: disconnect and manually ventilate with BVM.
- ›PEEP improves oxygenation by recruiting collapsed alveoli. High PEEP decreases cardiac output by reducing venous return.
- ›Tidal volume of 6 mL/kg of ideal body weight is the lung-protective target in ARDS (ARDSNet protocol).
- ›FiO₂ >60% for prolonged periods → oxygen toxicity. Always titrate to the lowest FiO₂ that maintains SpO₂ target.
- ›VAP prevention bundle: HOB 30–45°, oral care q4h, daily sedation vacation, and daily spontaneous breathing trial (SBT) readiness assessment.
- ›Plateau pressure >30 cmH₂O = barotrauma risk — notify provider; may require Vt reduction.
Related Resources
Standards & sources
Fact-checked Jun 21, 2026This page is written to align with American Association for Respiratory Care (AARC) · GOLD (COPD) / ATS / CHEST. It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →