Effect of BIS Monitoring on Propofol Usage During Elective Bronchoscopy

In this research, the investigators will asses the effect of BIS monitoring on propofol usage during elective flexible fiberoptic bronchoscopy. The investigators will examine whether use of BIS monitor enables reduction of sedative dose during bronchoscopy. The investigators will also examine whether administration of lower total sedative dose enables prevention of possible complications.

During flexible fiberoptic bronchoscopy (FFP) a narrow optic tube is inserted via the mouth or nose into the airways. This allows direct visualization of the airways as well as taking different samples. In addition, this procedure allows opening of airway obstruction. Administration of sedation during FFP is important, since this diminishes patient discomfort and body movements. It also lessens the untoward physiologic response to airway manipulation. In addition, patients requiring repeated examinations may refuse if they have suffered an unpleasant experience. FFP is usually a brief procedure (several minutes up to an hour). Therefore, it is advantageous to use short acting drugs in order to shorten the prolonged post procedural monitoring and allow rapid patient discharge. Several clinical trials have shown the superiority of propofol over midazolam for sedation during bronchoscopy regarding recovery of alertness, memory & motor function. Propofol is a sedative-hypnotic with rapid onset and short duration. Using propofol, one can achieve rapid onset of sedation and faster recovery. Propofol given in boluses of 10-20 mg was found as an effective dose to reach BIS target values. Awareness is the postoperative recollection of events occurring during general anesthesia. BIS is a monitor of anesthetic depth approved by the FDA. It incorporates time-domain, frequency-domain and bi-spectral analysis of the EEG. This analysis is displayed as a dimensionless number between zero (deep anesthesia) and 100 (awake). BIS values between 80-90 represent values corresponding to light/moderate sedation

Patients in this group will be monitored by BIS (placement of an electrode over the forehead before sedation). Patients in this group will receive propofol (boluses of 10-20 mg) to reach a BIS target value of 80-90.

BIS is a monitor of anesthetic depth approved by the FDA. It incorporates time-domain, frequency-domain and bi-spectral analysis of the EEG. This analysis is displayed as a dimensionless number between zero (deep anesthesia) and 100 (awake). BIS values between 80-90 represent values corresponding to light/moderate sedation. BIS is a valuable tool for assessing the depth of sedation and guiding the administration of sedative drugs.

The investigators will assess the occurrence of the following complications: hemodynamic instability, hypoxemia, respiratory depression.

Duration of flexible fiberoptic bronchoscopy (an average of 30 minutes) up to 10 minutes after completion of procedure

Inclusion Criteria: Over 18 years old Undergoing flexible fiberoptic bronchoscopy for lung tissue biopsy, airway lavage or opening of airway obstruction. Exclusion Criteria: Patient refusal/ inability to sign informed consent. Age under 18 years of age. Ventilated patients (via endotracheal tube or tracheostomy). Known allergy for one of the anesthetic drugs. Patients who suffered a stroke and/or have other neurological diseases. Hemodynamically unstable patients (SBP below 90mmHg or above 180mmHg).

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