Comparison Between VCV and FCV Through Ultra-thin Tube in Upper Airway Surgery

Comparative Study Between VolumeControlled Ventilation and FlowControlled Ventilation Through Ultra-thin Tube in Upper Airway Surgery

Ventilation through the small endotracheal tube is not an uncommon situation. The indications for it differ from elective upper airway surgery to emergency ventilation through needle cricothyrotomy. Conventionally, ventilation through small endotracheal tubes has been challenging by jet ventilation with subsequent risk of barotrauma and inadequate gas exchange. Expiration during jet ventilation occurs passively.

Upper airway endoscopy (micro laryngoscopy (MLS), pan endoscopy) is a minor upper airway procedure needing short duration general anesthesia, small calibrate endotracheal tube and manipulation of the airway. Because of airway manipulation and the surgery involves the airway, which is being shared with the anesthesiologist, there is a risk of interruption of ventilation, oxygenation and loss of airway in addition to inherent complications of surgery. Methods: After the patients will receive information about the study and informed consent will be taken. The patients will be randomized. In the control group, (group A) ventilation will be performed according to the routine big endotracheal tube. In the treatment group (group B), the ultra-thin ventilation tube will be placed using laryngoscopy. All other treatment will be unchanged. Data collection will be started 5 min after the initiation of the study. Demographic data, Past medical history, and examinations data will be collected after acceptance of the patient to be enrolled into the study and other ventilation parameters will be collected 5 min after the start of the the study which is Skin incision Primary endpoint is; to evaluate whether the Flow Controlled Ventilation (FCV) can also achieve adequate oxygenation and ventilation through small tube or not.

Patients who are scheduled for elective surgical upper airway surgery will be given General Anesthesia by an anesthesiologist who is the principal investigator and the surgical procedures will be done by the same ENT surgeon. IV Induction of Anesthesia with Propofol Target controlled infusion (TCI), Remifentanil Target controlled infusion (TCI) and Rocuronium (0.5mg/Kg) for muscle relaxation. The airway will be secured with cuffed endotracheal tube after direct laryngoscopy. After intubation by a Suitable size Endotracheal tube, they will be mechanically ventilated using Volume Controlled Ventilation (VCV) with 40% Oxygen and minute ventilation adjusted to keep ETCO2 of 40 mmHg or less, and a PEEP of 5 cmH2O.

General Anesthesia will be induced with IV Induction of Anesthesia by an anesthesiologist with Propofol (Target controlled infusion), Remifentanil (Target controlled infusion), and Rocuronium (0.5mg/Kg) for muscle relaxation. The airway will be secured with cuffed Tritube after direct laryngoscopy. They will be mechanically ventilated using Flow Controlled Ventilation (FCV) with 40% Oxygen, Flow rate:13L/Min., Peak Airway Pressure (15 cmH2O), and a PEEP of (5 cmH2O) to keep ETCO2 of 40 mmHg or less. The anesthesia will be maintained with Intravenous Infusion of Propofol, Remifentanil (TCI) to keep BIS 40-60.

Dynamic chest wall compliance changes due to Flow Controlled Ventilation (FCV) in comparison to routine Volume Controlled Ventilation(VCV)

This measures the airway resistance changes due to Flow Controlled Ventilation (FCV) in comparison to the traditional Volume Controlled Ventilation(VCV)

This will measure the patient oxygenation during intervention in both studied groups and using the arterial blood gases

This measures the patient ventilation during intervention in both studied groups using capnogram and arterial blood gases

Postoperative sore throat after 2 and 24 hours using the VAS score (0-10). (Zero=no pain and 10 = for the most sever pain.

Kink of the small (Tritube) (using machine alarms for obstruction and visual inspection) so will be (yes) for partial or complete obstruction and (no) for the absence of obstruction)

the Surgeon satisfaction score according the space free for the surgery which range from (1= poor, 2= medium, 3= good, 4= very good, and 5= excellent).

Inclusion Criteria: Adult population of both sex (ASA I, II). Between18-65 years of age. Patients for the upper airway. Patients need intubation/invasive mechanical ventilation. Exclusion Criteria: ASA >II Advanced Respiratory disease. Advanced cardiovascular disease. Smokers. Pregnancy. Recent upper airway trauma. Age less than 18 years or more than 65 years. Patients BMI of more than 35 Refuse to sign the consent.

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