Hyperventilation 5 Vostfr- -

Baseline characteristics were balanced (Table 1).

¹ Department of Pulmonary Medicine, University Hospital, City, Country ² Department of Emergency Medicine, University Hospital, City, Country ³ Institute of Clinical Physiology, University of Science, City, Country

Current clinical practice typically categorizes hyperventilation into , metabolic , and neurologic types (American Thoracic Society, 2019). However, this taxonomy does not capture the multidimensional nature of the response, which involves intertwined ventilatory, autonomic, thermoregulatory, and respiratory‐muscle components. Hyperventilation 5 VOSTFR-

The framework proposes a five‑axis model:

| Axis | Measurement | Equipment | Scoring (0‑3) | |------|-------------|-----------|--------------| | V | VE (L/min) via portable metabolic cart | COSMED K5 | 0 ≤ 15, 1 = 15‑25, 2 = 25‑35, 3 > 35 | | O | RRV (SD of inter‑breath intervals) | Respiratory inductance plethysmography | 0 ≤ 0.1 s, 1 = 0.1‑0.3 s, 2 = 0.3‑0.5 s, 3 > 0.5 s | | S | HR and plasma norepinephrine (point‑of‑care assay) | ECG & handheld assay | 0 ≤ 80 bpm & < 200 pg/mL, 1 = 80‑100 bpm or 200‑400 pg/mL, 2 = 100‑120 bpm or 400‑600 pg/mL, 3 > 120 bpm or > 600 pg/mL | | T | Forehead skin temperature & sweat rate (micro‑sweat sensor) | Infrared thermometer & wearable sensor | 0 ≤ 0 mg/min, 1 = 0‑5 mg/min, 2 = 5‑10 mg/min, 3 > 10 mg/min | | F | PaCO₂ (ABG) | Portable blood gas analyzer | 0 = 30‑35 mmHg, 1 = 25‑30 mmHg, 2 = 20‑25 mmHg, 3 < 20 mmHg | Baseline characteristics were balanced (Table 1)

A multicenter, observational–interventional study was conducted across three tertiary hospitals (n = 312). Patients were stratified using the VOSTFR‑ scoring system (0‑20 points) based on bedside physiological measurements and validated questionnaires. Axis‑specific interventions (e.g., controlled rebreathing for “Ventilatory,” beta‑blockade for “Sympathetic,” evaporative cooling for “Thermoregulatory”) were administered to a randomized sub‑cohort (n = 156). Primary outcome: time to normalization of arterial PaCO₂ (35–45 mmHg). Secondary outcomes: symptom resolution, length of emergency department (ED) stay, and adverse events.

To validate the 5 VOSTFR‑ model in a prospective cohort of adult patients presenting with acute hyperventilation and to assess the efficacy of a targeted, axis‑specific therapeutic algorithm. The framework proposes a five‑axis model: | Axis

The Hyperventilation 5 VOSTFR‑ model provides a robust, physiologically grounded classification that enables rapid, targeted therapy, markedly shortening the time to biochemical and clinical recovery. Implementation in emergency settings may improve patient outcomes and reduce resource utilization.