How the model works
Five infusion snapshots affect circulation and spontaneous ventilation.
Propofol, ketamine, midazolam, dexmedetomidine and fentanyl use Off/Low/Medium/High infusion snapshots. Their internal strengths are 0, 0.30, 0.65 and 1.00. No bolus phase, drug accumulation or depth-of-anesthesia monitor is modeled.
The same sedation result affects rhythm/rate, vascular tone, contractility, venous filling and spontaneous respiratory drive. Required procedural sedation is not automatically labeled a new critical collapse solely because a sedative was selected.
Propofol/midazolam reduce vascular and venous tone; dexmedetomidine and fentanyl contribute to slowing. Ketamine uses an assumed sympathetic-reserve factor derived from starting MAP and pump-failure phenotype; low reserve can expose myocardial depression. The model is not measuring catecholamine stores.
Atropine attenuates selected vagal slowing; beta blockade attenuates ketamine stimulation and can amplify bradycardic burden. Captured pacing and VT/VF retain their own timing. Flow loss is greater with pump failure, depleted preload or an obstructed inflow/outflow pathway.
A combined depression index includes opioid–sedative synergy. Its exponential reduction factor is divided between spontaneous rate and tidal depth. Above the selected apnea threshold, spontaneous breaths cease. These are chosen response coefficients, not human dose–apnea probabilities.
Mandatory ventilation can continue despite loss of drive. Pressure support requires a trigger and has no automatic backup here. Hypoventilation can increase CO₂, reduce alveolar oxygen, raise pulmonary load and worsen RV delivery; supplemental oxygen alone does not restore ventilation. Ketamine supplies a modest bronchodilator term in the bronchospasm example.
Critical deterioration compares otherwise matching states with and without sedation. Examples include newly severe hypotension, substantial output loss, marked bradycardia or extreme pressure rise. Pre-existing shock and modest expected procedural changes are not sufficient by themselves.
This UI policy does not certify that sedation is safe. Airway obstruction, aspiration, delirium, drug concentrations and procedural complications are not predicted.
