A prospective, double-blind, randomized, placebo and active controlled, multi-center, parallel group study comparing remimazolam to placebo, with an additional open label arm for midazolam, in patients undergoing a bronchoscopy.

Inclusion Criteria:

1. Male and female patients, aged ≥18 years, scheduled to undergo a diagnostic or therapeutic flexible bronchoscopy in the bronchoscopy suite (therapeutic bronchoscopies could include eg, lavage, biopsies, brushings, and foreign body extraction).
2. American Society of Anesthesiologists Physical Status Score (ASA PS) 1 through 3.
3. Body mass index (BMI) ≤ 45.
4. Peripheral blood oxygen saturation (measured by pulse oximetry: SpO2) ≥ 90% in ambient air or with no more than 2 L/min of oxygen support.
5. For all female patients, negative result of urine pregnancy test. Additionally, for women of child bearing potential only, use of birth control during the study period (from the time of consent until all specified observations were completed).
6. Patients voluntarily signed and dated an informed consent form that was approved by an IRB prior to the conduct of any study procedure, including screening procedures.
7. Patient was willing and able to comply with study requirements and available for a follow up phone call on Day Day 4 (+3/ 1 days) after the bronchoscopy.

Exclusion Criteria:

1. Patients with a known sensitivity to benzodiazepines, flumazenil, opioids, naloxone, or a medical condition such that these agents were contraindicated.
2. Bronchoscopy outside the bronchoscopy unit (eg, intensive care unit).
3. Patients on mechanical ventilation.
4. Tracheal stenosis.
5. Planned laser bronchoscopy, rigid scope bronchoscopy.
6. Use of unstable doses of benzodiazepines and opioids for any indication, eg, insomnia, anxiety, or spasticity. An unstable dose means dose changes of more than 50% of the previous dose within 30 days prior to Day of procedure.
7. Female patients with a positive pregnancy test at Screening or Baseline and lactating female patients.
8. Patients with positive drugs of abuse screen (unless explained by concomitant medication) or a positive ethanol test at baseline.
9. Patient with a history of drug or ethanol abuse within the past two years.
10. Patients in receipt of any investigational drug or use of investigational device within 30 days or less than 7 t½ (whichever was longer) before the start of the study or scheduled to receive one during the study period.
11. Participation in any previous clinical study with remimazolam.
12. Patients with an inability to communicate well in English with the investigator or deemed unsuitable according to the investigator (in each case providing a reason).