The Predictor of Respiratory Discomfort After the Shoulder Arthroscopic Surgery

• Airway transverse diameter [ Time Frame: 10 min before anesthesia induction ] [ Designated as safety issue: No ]
  airway transverses diameter measured on the upper airway ultrasonographic image: measure at three level (vocal cord, subglottis, trachea)
  
  
• Airway transverse diameter [ Time Frame: 20 min after end of surgery ] [ Designated as safety issue: No ]
  airway transverses diameter measured on the upper airway ultrasonographic image: measure at three level (vocal cord, subglottis, trachea)
  
  

• depth of skin to airway anterior border [ Time Frame: 10 min before anesthesia induction and 20 min after the surgery ] [ Designated as safety issue: No ]
  depth of skin to airway anterior border measured at three levels: vocal cord, subglottis, trachea level
  
  
• depth of skin to pleura [ Time Frame: 10 min before anesthesia induction and 20 min after the end of surgery ] [ Designated as safety issue: No ]
  bilateral depth of skin to pleura at first and third intercostal space on the midclavicualr line measuread on the ultrasonographic image
  
  
• endotracheal tube balloon cuff pressure [ Time Frame: 10 min after anesthesia induction and 60 min after surgery start ] [ Designated as safety issue: No ]
  endotracheal tube balloon cuff pressure
  
  
• percent cuff leak [ Time Frame: 10 min after anesthesia induction and 60 min after surgery start ] [ Designated as safety issue: No ]
  The difference in the actual exhaled volume between the averages of pre- and post-cuff deflation was calculated. This number was divided by the tidal volume before cuff deflation and multiplied by 100. The resulting number was recorded as the percent cuff leak.
  
  

During shoulder arthroscopic surgery, extravasation of irrigation fluid can occur around the shoulder and trachea, compressing the upper airway. Although the extravasation is generally reabsorbed asymptomatically within 12 hours, there are cases that lead to reintubation or life-threatening complications.

An endotracheal tube is the most reliable method of securing the airway from airway obstruction during a shoulder arthroscopy surgery. However, since the airway may become obstructed after extubation, airway patency should be verified before extubation. Direct visualization of the larynx or trachea using laryngoscopy or bronchoscopy is difficult due to the presence of the tracheal tube. A cuff leak around the tracheal tube in a cuff-deflated condition is suggested to be a predictor of successful extubation. However, its reliability has been questioned in adult patients. A cuff leak could be affected by paratracheal pressure, which is thought to be elevated during shoulder arthroscopy. In a recent study, it was shown that laryngeal ultrasound can be a reliable, non-invasive method for the evaluation of laryngeal morphology or predicting post-extubation stridor.

The investigators applied upper airway ultrasonographic examination focusing the measurement of upper airway diameters in patients undergoing shoulder arthroscopic surgery to evaluate the change of upper airway anatomy before and after the surgery. The investigators also tried to find any findings of ultrasonographic examination that could reliably predict the dyspnea or airway compression after extubation. The investigators tried to compare the ultrasonographic findings with those of chest radiograph to validate the measurements of the ultrasonographic examination. A cuff leak test was preformed to evaluate its ability to predict the upper airway obstruction in shoulder arthroscopic surgery.