Why: After thyroid or neck surgery, some patients can lose movement of both vocal cords (bilateral vocal-cord paralysis, BVCP). This can make breathing difficult and often leads to an emergency or preventive tracheostomy ("wind-pipe") surgery.

What: This study will test two simple ways to avoid a tracheostomy:

Pre-operative BiPAP sleep training - patients practice sleeping with a non-invasive BiPAP breathing machine for seven nights before surgery so they become comfortable with the mask and pressures.

Immediate post-extubation BiPAP support - the same BiPAP machine is started as soon as the breathing tube is removed in the operating room or recovery area.

How: Adults (18-80 years) who already have, or are at high risk of getting, BVCP will be randomly assigned to one of four groups in a 2 × 2 design:

• Group 1: training + post-op BiPAP • Group 2: training only • Group 3: post-op BiPAP only • Group 4: standard care (no planned BiPAP).

Main goal: To find out whether either or both BiPAP strategies reduce the need for tracheostomy or re-intubation during the first 7 days after surgery.

What participants do: Eligible patients will undergo routine surgery plus the assigned BiPAP plan. Breathing events, comfort, hospital stay, and voice quality will be recorded up to 6 months.

Potential benefit/risk: BiPAP is non-invasive and already FDA-cleared for home and hospital use, but some people may feel mask discomfort or air leaks. Trained staff will adjust settings and stop BiPAP if serious problems occur.

Background and Rationale Bilateral vocal-cord paralysis (BVCP) after thyroid and neck procedures poses an immediate risk of airway obstruction. Historical management favors prophylactic or rescue tracheostomy; however, tracheostomy carries morbidity, cost, and long-term stigma. Case series suggest that non-invasive ventilation (NIV) using BiPAP can stent the glottic opening while providing ventilatory support, but no prospective randomized data exist.

Objectives Primary: Compare the 7-day composite rate of (a) tracheostomy or (b) re-intubation among patients managed with (i) pre-operative BiPAP training, (ii) immediate post-extubation BiPAP, both, or neither.

Secondary: BiPAP usage hours, hypoxemic events, ICU/hospital length of stay, Voice Handicap Index-10 (VHI-10) and Eating Assessment Tool-10 (EAT-10) scores, normalized glottic area (NGA %) at 6 months, cost.

Study Design Multicenter, open-label, factorial (2 × 2) randomized controlled trial. Randomization (block size = 4) stratified by center. Total planned enrollment: 204 (to allow for 10 % attrition), yielding ~46 evaluable participants per arm.

Interventions Pre-operative BiPAP training: nightly ≥ 4 h for 7 consecutive nights, pressure ladder EPAP 6 → 8 cmH₂O / IPAP 12 → 16 cmH₂O, recorded on SD-card.

Post-extubation BiPAP: same machine and pressures applied immediately after extubation and continued ≥ 48 h or until patient maintains SpO₂ ≥ 94 % for 24 h without BiPAP.

Standard care includes oxygen, nebulization, steroids, and surgical airway if necessary.

Eligibility (key points) Inclusion: age 18-80; scheduled thyroid/neck surgery; pre-op fixed cords at midline/paramedian or glottic gap ≤ 3 mm OR ≥ 2 high-risk factors (bilateral neck re-entry, tumor near both RLNs, bilateral C + L lymph-node dissection, severe OSA AHI ≥ 30, BMI ≥ 30).

Exclusion: emergency surgery, existing tracheostomy, ventilator dependence, mask intolerance, pregnancy, inability to consent.

Outcomes and Assessments

• Airway status monitored continuously POD 0-2, then daily to POD 7.
• ABG, pulse oximetry, and flexible laryngoscopy performed per protocol schedule.
• Adverse events graded by CTCAE v5.0; DSMB halting rule: ≥ 3 grade 3 airway failures in any arm.

Statistical Methods Intention-to-treat for primary endpoint. Log-binomial regression with center as random effect to estimate risk ratios for each main effect and their interaction. Kaplan-Meier curves for "tracheostomy-free survival." Interim analysis at 50 % information using O'Brien-Fleming alpha-spending.

Regulatory Status Devices (ResMed AirCurve 10 ST; Philips A40) are FDA-cleared class II ventilators (510(k)); IRB classified study as non-significant-risk device research exempt from IDE under 21 CFR 812.2(b).

Data Sharing De-identified individual participant data and statistical code will be shared upon reasonable request 6 months after final publication.

Inclusion Criteria:

• Age 18 - 80 years.

• Scheduled for thyroidectomy or other neck surgery under general anesthesia.

• High risk of bilateral vocal-cord paralysis (BVCP) defined by at least ONE of:

  • Pre-operative flexible laryngoscopy showing fixed vocal cords at midline or paramedian position, or glottic gap ≤ 3 mm; OR

  • Presence of ≥ 2 high-risk factors:

    • Planned bilateral central plus lateral neck dissection
    • Re-operative bilateral neck surgery or dense scarring
    • Tumor involving both recurrent laryngeal nerves or crico-arytenoid joints
    • Severe obstructive sleep apnea (AHI ≥ 30 events/hour)
    • Body-mass index (BMI) ≥ 30 kg/m²

• Able to tolerate and give informed consent for BiPAP mask use.

Exclusion Criteria:

• Emergency surgery or need for immediate tracheostomy.
• Existing tracheostomy or home ventilator dependence.
• Inability to protect airway (e.g., Glasgow Coma Scale < 13).
• Craniofacial anomaly or skin condition precluding mask seal.
• Pregnancy or breastfeeding.
• Participation in another interventional trial that could interfere with study endpoints.

Open-label; blinding not feasible because BiPAP mask/pressures are apparent. Primary endpoint (tracheostomy or re-intubation) is objective.