"TRAcheostomy With Single Use Bronchoscopes vs. Conventional Bronchoscopes"

Background Long-term ventilated critically ill patients often receive a tracheostomy to facilitate weaning from the ventilator and for prevention of secondary complications by the endotracheal tube. Besides surgical tracheostomy in which a muco-cutaneous fistula is prepared between trachea and outer skin, percutaneous tracheostomy (PDT) has been introduced, in which a cannula is being inserted into the trachea. After introduction of a guidewire, the trachea is then dilated. This intervention should be led by optical guidance, i. e. to verify the correct point of tracheal cannulation between the 2nd and 3rd tracheal cartilage and to minimize the risk for accidental injury to the membranous part of the trachea. Usually, optical guidance is performed by conventional multi use bronchoscopy. During bronchoscopy in ventilated patients, a drop in minute ventilation or an increase of carbon dioxide partial pressure with a consecutive respiratory acidosis may occur. Recently, a single use bronchoscope has been introduced that permits a continuous visualisation of the trachea on a monitor connected to the camera (Ambu® aScopeTM 4, Ambu, Ballerup, Denmark) . In this study, it is being evaluated whether the optical guidance during PDT can be performed by the Ambu® aScope 4. The advantage of a single use bronchoscope for percutaneous dilatative tracheostomy in comparison to a conventional reuseable bronchoscope is that there is no need for repair or decontamination after use.

Methods:

Design of Study/ No. of Patients:

Randomized, prospective study/ 46 patients With a sample size of 46 (randomized 1:1 in 2 groups of 23 each) a difference of 35% on a visualization score [6] may be seen with an α-error of 0,05 and a β-error of 1-0,8.

Procedures:

• screening for study inclusion according to inclusion and exclusion criteria.
• Percutaneous tracheostomy with Ciaglia Blue Rhino technique
• Visualization of PDT via a conventional multi use bronchoscope vs the aScopeTM 4 single use bronchoscope.

study inclusion: All patients being treated in the Dept. of Intensive Care Medicine receiving percutaneous tracheostomy due to long term ventilation are screened according to inclusion and exclusion criteria.

Details of study-procedures:

Bronchoscopy:

The bronchoscopy for percutaneous tracheostomy is done according to the standard operating procedure of the Dept. for Intensive Care Medicine. Furthermore, during this study the bronchoscopy is done by a physician with an experience of more than 200 bronchoscopies.

Percutaneous Tracheostomy:

The tracheostomy is performed according to the Ciaglia Blue Rhino method(Ciaglia Blue Rhino® G2, Cook Medical, Bloomington, IN, USA). After skin incision and an optional blunt dissection of the subcutaneous tissue, the trachea is cannulated between the 2nd and 3rd tracheal cartilage.

Visualization is provided by a conventional multi use bronchoscope or by a single use bronchoscope. Should visualization be insufficient by a single use bronchoscope backup is provided by a conventional multi use bronchoscope.

The tracheostomy is performed by an experienced fellow or attending physician. rating of visualization of tracheal structures and ventilation during percutaneous dilatational tracheostomy:

Rating (each item 1 to 4 points)

A) Identification of: thyroid cartilage, cricoid cartilage, 1st-3rd tracheal cartilage:

1 Reliable identification; 2 Only cricoid cartilage and tracheal cartilages; 3 Only tracheal cartilages; 4 No vision on tracheal structures

B) Visualization of tracheal circumference:

1 Complete; 2 circumference 1/3 to 2/3 of circumference; 3 Only small parts of trachea; 4 No vision on tracheal structures

C) Monitoring puncture: midline + level below 1st or 2nd tracheal cartilage:

1 Reliable identification; 2 Midline sure Level uncertain, but below the 1st tracheal cartilage; 3 Level of puncture uncertain; 4 No vision on tracheal structures

D) Monitoring dilatation Anterior wall and Pars membranacea (P.m.) visible:

1 Reliable identification; 2 P.m. only; 3 Only small parts of trachea visible, no control of P.m.; 4 No vision on tracheal structures

E) Quality of Ventilation Before puncture and worst ventilation during PDT, respectively:

1 Minute ventilation (MV) as before starting tracheotomy; 2 MV < 2 L/min or oxygen saturation (SO2) 80-90% (>2minutes); 3 MV < 0,5l /min or SO2 70 - 79% (> 2 minutes); 4 MV = 0 or SO2 < 70% (> 2 minutes)

F) Quality of the suction channel:

1 Uncomplicated suction of secretion; 2 suction only under flush; 3 suction only possible after multiple removing and flushing of the bronchoscope.; 4 suction not possible.

Consent: all patients or their legal surrogate give written informed consent.

Data protection: Data are anonymized.

Inclusion criteria

• Patients receiving percutaneous tracheotomy in the Dept. of Intensive Care Medicine.
• Age ≥ 18 years
• Informed consent

Exclusion criteria

• Age < 18 years
• No consent
• Direct laryngoscopy according to Cormack-Lehane ≥ 3