Expanded Access for Inhaled Isoflurane Delivered Via the Sedaconda ACD-S for Sedation of Difficult-to-Sedate Adult Mechanically Ventilated Intensive Care Unit Patients

Inclusion Criteria: * Adults ≥18 years of age; * Receiving invasive mechanical ventilation and continuous sedation in the ICU; * Inability to maintain a target sedation level ensuring patient comfort and safety with conventional intravenous sedatives, in clinically appropriate combinations and at maximum tolerated doses, despite optimized analgesia and ventilator settings, with 1. recurring episodes of agitation or self-harm, such as attempting or actual removal of an endotracheal tube or of indwelling catheters or monitors, or necessitating physical restraints; or 2. escalating sedative and opioid drug doses, despite mitigating strategies (e.g., sedative drug combinations or rotation to reduce toxicity); or 3. clinical concerns for, or indications of, serious untoward effects of ongoing conventional intravenous sedation and analgesia agents (e.g., hypertriglyceridemia, propofol-related infusion syndrome, bradycardia, iatrogenic withdrawal syndrome); and * No other available sedative option is considered appropriate * Is not currently enrolled in or is eligible for a clinical study that would prohibit the participation in this EAP. Exclusion Criteria: * Ventilator tidal volume \<200 or \>1000 mL * Need for high frequency oscillation ventilation (HFOV) or high frequency percussive ventilation (HFPV) * Comfort care only (end of life care); * Suspected but unmonitored elevated intracranial pressure (e.g., patients with acute stroke, severe head trauma, meningitis without ICP monitoring); * Contraindication to isoflurane, including: 1. Known or suspected personal or family history of malignant hyperthermia (MH) or high risk for MH or acute drug-induced muscle injury (eg, muscular dystrophies); 2. Severe hemodynamic compromise; 3. Known hypersensitivity reaction to isoflurane or other halogenated volatile anesthetic agents * History of ventricular tachycardia/Long QT Syndrome; * Female patients who are pregnant or breast-feeding; * Imperative need for continuous active humidification through mechanical ventilation circuit; * Any medical conditions, that, in the Investigator´s opinion, would impose excessive risk to the patient or would adversely affect the patient's participation in the EAP; * Inability to obtain informed consent.