The Effect of the Shoulder Arthroscopic Surgery on Respiratory Mechanics

• Static compliance [ Time Frame: before and after arthroscopic surgery, an expected average of 80 minutes ] [ Designated as safety issue: No ]

  Static compliance (mL/cmH2O) before and after the arthroscopic surgery

  ,Static compliance = tidal volume delivered / (plateau pressure - PEEP)

• dynamic compliance [ Time Frame: before and after arthroscopic surgery, an expected average of 80 minutes ] [ Designated as safety issue: No ]

  dynamic compliance (mL/cm H2O) before and after the arthroscpic surgery

  ,dynamic compliance = tidal volume delivered / (peak pressure - PEEP)

• inspiratory tidal volume [ Time Frame: before and after arthroscopic surgery, an expected average of 80 minutes ] [ Designated as safety issue: No ]
  inspiratory tidal volume (ml) before and after the arthroscpic surgery
• expiratory tidal volume [ Time Frame: before and after arthroscopic surgery, an expected average of 80 minutes ] [ Designated as safety issue: No ]
  expiratory tidal volume (ml) before and after the arthroscpic surgery
• peak inspiratory pressure [ Time Frame: before and after arthroscopic surgery, an expected average of 80 minutes ] [ Designated as safety issue: No ]
  peak inspiratory pressure (cm H2O) before and after the arthroscpic surgery
• physiologic dead space [ Time Frame: before and after arthroscopic surgery, an expected average of 80 minutes ] [ Designated as safety issue: No ]

  physiologic dead space (VD/VT) before and after arthroscopic surgery

  ,VD/VT = (PaCO2 - PeCO2)/PaCO2, PeCO2 = mixed expired CO2

• plateau airway pressure [ Time Frame: before and after arthroscopic surgery, an expected average of 80 minutes ] [ Designated as safety issue: No ]
  plateau airway pressure (cmH2O) before and after arthroscopic surgery
• Mean airway pressure [ Time Frame: before and after arthroscopic surgery, an expected average of 80 minutes ] [ Designated as safety issue: No ]
  Mean airway pressure (cm H2O) before and after arthroscopic surgery
• positive end expiratory pressure [ Time Frame: before and after arthroscopic surgery, an expected average of 80 minutes ] [ Designated as safety issue: No ]
  positive end expiratory pressure (cmH2O) before and after arthroscopic surgery
• inspiratory resistance [ Time Frame: before and after arthroscopic surgery, an expected average of 80 minutes ] [ Designated as safety issue: No ]
  inspiratory resistance (cmH2O/L sec) before and after arthroscopic surgery
• expiratory resistance [ Time Frame: before and after arthroscopic surgery, an expected average of 80 minutes ] [ Designated as safety issue: No ]
  expiratory resistance (cmH2O/ L sec)before and after arthroscopic surgery
• peak inspiratory flow [ Time Frame: before and after arthroscopic surgery, an expected average of 80 minutes ] [ Designated as safety issue: No ]
  peak inspiratory flow (L/min) before and after arthroscopic surgery
• peak expiratory flow [ Time Frame: before and after arthroscopic surgery, an expected average of 80 minutes ] [ Designated as safety issue: No ]
  peak expiratory flow (L/min) before and after arthroscopic surgery
• Work of breathing [ Time Frame: before and after arthroscopic surgery, an expected average of 80 minutes ] [ Designated as safety issue: No ]
  Work of breathing (J/L) before and after arthroscopic surgery
• end tidal CO2 [ Time Frame: before and after arthroscopic surgery, an expected average of 80 minutes ] [ Designated as safety issue: No ]
  end tidal CO2 (mmHg) before and after arthroscopic surgery
• arterial oxygen tension [ Time Frame: before and after arthroscopic surgery, an expected average of 80 minutes ] [ Designated as safety issue: No ]
  arterial oxygen tension (mmHg) measured by arterial blood gas analysis
• arterial CO2 tension [ Time Frame: before and after arthroscopic surgery, an expected average of 80 minutes ] [ Designated as safety issue: No ]
  arterial CO2 tension (mmHg)as measured by arterial blood gas analysis
• forced vital capacity (FVC) [ Time Frame: before and after general anesthesia, an expected average of 120 minutes ] [ Designated as safety issue: No ]
  forced vital capacity measured by portable spirometry
• forced expiratory volume for 1 second (FEV1) [ Time Frame: before and after general anesthesia, an expected average of 120 minutes ] [ Designated as safety issue: No ]
  forced expiratory volume for 1 second (FEV1)measure by portable spirometry

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. Furthermore, the soft tissue edema around the shoulder may extend to the thoracic cage, compress the chest and induce the respiratory distress immediately after surgery. The investigators attempt to determine the effect of shoulder arthroscopic surgery on respiratory mechanics. Changes in respiratory mechanics and arterial blood gases were measured and compared before and after the shoulder arthroscopic surgery.

Currently, most shoulder surgeries are performed with arthroscopy. The advantages of shoulder arthroscopic surgery are decreased blood loss due to minimal incision for scope, a reduced operation time, minimization of surgical stress, and rapid recovery time after surgery. 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. Furthermore, the soft tissue edema around the shoulder may extend to the thoracic cage, compress the chest and induce the respiratory distress immediately after surgery. From these facts, the mechanism of respiratory discomfort after shoulder arthroscopic surgery may be because the upper airway obstruction or restrictive pathology due to direct compression of thoracic cage by the soft tissue edema. There have been no studies on the respiratory effect of shoulder arthroscopic surgery. We have observed frequent and severe respiratory discomfort after the shoulder arthroscopic surgery. Therefore, in this study we attempt to determine the effect of shoulder arthroscopic surgery on respiratory mechanics. Changes in respiratory mechanics and arterial blood gases were measured and compared before and after the shoulder arthroscopic surgery.

patients undergoing arthroscopic shoulder rotator cuff repair surgery

Inclusion Criteria:

• Patients undergoing arthroscopic shoulder rotator cuff repair surgery
• American society of anesthesiologist (ASA) class I or II
• Patients under 70 yrs.

Exclusion Criteria:

• Patients older than 70 yrs,
• Patients with anatomical derangement of upper airway,
• Patients with pulmonary or cardiac disease,
• Patients with a history of laryngeal or tracheal surgery or hemodynamic instability