| 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 |
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.
The framework proposes a five‑axis model: Hyperventilation 5 VOSTFR-
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.
Baseline characteristics were balanced (Table 1). | Axis | Measurement | Equipment | Scoring
Hyperventilation, VOSTFR, respiratory physiology, acute care, targeted therapy, ventilatory control 1. Introduction Hyperventilation, defined as an increase in alveolar ventilation that exceeds metabolic CO₂ production, leads to arterial hypocapnia (PaCO₂ < 35 mmHg) and a cascade of neuro‑vascular and metabolic effects (Brown & Smith, 2021). While often benign, severe or prolonged episodes can precipitate cerebral vasoconstriction, tetany, arrhythmias, and, in extreme cases, loss of consciousness (Klein et al., 2020).
Hyperventilation 5 VOSTFR‑: A Novel Classification and Therapeutic Framework for Acute Respiratory Dysregulation Baseline characteristics were balanced (Table 1)
| Axis | Physiologic Domain | Representative Markers | |------|--------------------|------------------------| | (Ventilatory) | Central respiratory drive, lung mechanics | Minute ventilation (VE), tidal volume (VT) | | O (Oscillatory) | Respiratory rhythm stability | Respiratory rate variability (RRV) | | S (Sympathetic) | Autonomic tone | Heart rate (HR), catecholamine levels | | T (Thermoregulatory) | Body temperature regulation | Skin temperature, sweat rate | | F (Respiratory) | Gas exchange efficiency | PaCO₂, alveolar‑arterial gradient |
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
Each axis can be scored (0 = absent, 1 = mild, 2 = moderate, 3 = severe) yielding a composite (0–15). The suffix “‑” denotes the presence of a dominant axis (the one with the highest individual score) that guides therapeutic priority.