Anesthesiology

ARTHROSCOPIC shoulder surgery is an accepted technique for managing rotator cuff tears, recurrent joint instability, and subacromial pathology. ¹Shoulder arthroscopy has several important advantages over open techniques, including less postoperative pain and more rapid rehabilitation. ²Regional anesthesia for arthroscopic shoulder surgery is increasingly used. Advantages include less overall anesthetic drugs received by the patient, reduced postoperative analgesic requirements, lower rates of postoperative nausea, and reduced admission rates. ³

Rarely, arthroscopic shoulder surgery under regional anesthesia produces complications that compromise the patient's airway. ^4–7This report describes a case of life-threatening airway edema due to extracapsular irrigation fluid collection during a prolonged shoulder arthroscopic repair.

Case Report

A 49-yr-old, healthy man presented for right shoulder arthroscopic surgery, subacromial decompression, and rotator cuff repair. He was receiving no medications and had no drug allergies. On physical examination, the patient was 70 inches tall, weighed 82 kg, and had clear lungs and regular heart sounds. His oral examination revealed a Mallampati class 2 airway, with a normal cervical range of motion.

In the preoperative holding area, the patient received 2 mg intravenous midazolam and 100 μg of fentanyl for sedation. The right side of his neck was prepared in sterile fashion. With the aid of a nerve stimulator (Stimuplex, B. Braun, Bethlehem, PA), a 25-mm, 24-gauge, insulated needle was used to elicit stimulation of the deltoid muscle, with a current of 0.4 mA. Then, 40 ml of levobupivacaine, 0.56% with epinephrine 1:300,000, was injected, and brachial plexus block was evident within 10 min.

The patient was placed in the “beach-chair” position in the operating room, monitors were attached, and sedation was initiated with a propofol infusion of 100 μg · kg⁻¹· min⁻¹. The patient was unconscious but was able to be aroused and continued to breathe supplemental oxygen spontaneously; end-tidal carbon dioxide was monitored via  a catheter placed inside the oxygen mask.

Arthroscopy proceeded uneventfully for several hours. Joint irrigation was accomplished with lactated Ringer's solution with diluted epinephrine, using an infusion pump with pressures varying between 50 cm H²O and 150 cm H²O. The patient's arterial oxygen saturation (Sao²) remained in the 97–98% range. However, approximately 3 h after the procedure was begun, the Sao²began to decrease, and audible stridor occurred. End-tidal carbon dioxide tension levels decreased from 15–20 mmHg to unobtainable levels. The surgeon was notified that severe neck and chest edema had caused respiratory arrest and that intubation would be necessary. Drapes were removed, revealing extensive swelling across the entire chest and neck as well as facial edema. The right side of the chest was woody in texture because of the extreme edema, and the overlying skin appeared mottled. Neck mobility was compromised, and laryngeal landmarks were not recognizable visibly or by palpation.

The Sao²rapidly decreased to 67%, cyanosis supervened, and there was no evidence of effective spontaneous ventilation. Positive pressure ventilation by facemask was impossible. The patient resisted attempts to open the mouth, and general anesthesia was induced with a bolus of 120 mg of propofol and 120 mg of succinylcholine. Direct laryngoscopy revealed marked airway edema, with bulging pharyngeal tissues that made recognition of the glottis impossible.

On failure of direct laryngoscopy, a Laryngeal Mask AirwayTM (LMA Unique  TM, LMA of North America, Los Angeles, CA) was inserted into the pharynx and ventilation was initiated. The patient's chest was noted to rise with manual ventilation, and the Sao²rapidly climbed to 95%, with detectable levels of end-tidal carbon dioxide. However, the Sao²began to deteriorate once again, necessitating a more secure airway. A fiberscope was passed into the LMA Unique  TM, and the aperture of the airway was recognized but was much reduced in size by the surrounding edema. The tip of the scope was passed through the laryngeal inlet, and a 6.0-mm endotracheal tube (ETT) was passed successfully.

Preparations were made to change the tube to one with greater length than the 6.0-mm ETT, which is restricted to a very short segment in the trachea by the LMA Unique  TM. A tube-exchange device (Cook Critical Care, Bloomington, IN) was inserted through the existing ETT. The LMA Unique  TM and 6.0-mm ETT were removed, and a 7.0-mm tube was passed over the catheter against a degree of resistance. The exchange device was removed with difficulty, but ventilation through the new ETT was not effective. There was an audible air leak in the pharynx during ventilation, and no chest rise or end-tidal carbon dioxide was evident. Direct laryngoscopy was again attempted, and the ETT was curled in the posterior pharynx. It was removed, and the glottic opening was now recognizable from the fiberscopic intubation. A gum elastic bougie was placed through the small opening, and a 7.0-mm ETT was passed over this stylet.

The patient was transferred to the recovery room, and then to the intensive care unit, while sedation and mechanical ventilation were continued. Chest radiography revealed near-complete opacification of the right hemithorax. Computed tomography of the chest showed a large right pleural effusion with atelectasis of the lower and middle lobes, and marked edema of the right side of the neck with laryngeal displacement to the left. Hemodynamic stability was maintained, and diuresis was begun.

After 24 h, the patient's facial appearance had returned to nearly normal, although significant chest and neck swelling remained. An inspired fraction of oxygen of 80% was still necessary for adequate oxygenation. On the second postoperative day, the clinical situation had greatly improved and the patient was extubated that evening. Despite the repeated glottic intubations and manipulation, there were no complications. He was discharged home on postoperative day 5.

Discussion

This report describes an episode of severe airway edema occurring as a complication of shoulder arthroscopic surgery. Complications related to shoulder arthroscopy are not infrequent. Small ⁸describes an incidence of complications of 5.3%. Bigliani et al.  ⁹characterized the frequency of complications as 1–3.2%, depending on the nature of the procedure. Complications described include extravasation of fluid, traction neuropraxias, intraoperative hemorrhage, infections, cartilage injury, and reflex sympathetic dystrophy.

However, respiratory compromise related to shoulder arthroscopy procedures is rare. Causes include air embolism, ¹pneumothorax, ⁶mediastinal air, ⁷tracheal compression, ⁵and complete airway obstruction from edema. ⁴Borgeat et al.  ⁵reported a case of airway compromise in a patient who underwent interscalene block for an arthroscopic procedure on the left shoulder. Infusion of normal saline into the shoulder was initiated at a pressure of 80 mmHg, and then increased after 2 hr, at which time the surgeon noted a leak of fluid from the joint. The patient then complained of neck pressure, shortness of breath, and chest tightness. Wheezing and marked left-sided chest and neck edema were evident on examination. The patient, who was in the lateral decubitus position, was placed supine with her head elevated. She did not develop hypoxemia, and she recovered with no further intervention.

Complete airway obstruction during arthroscopic shoulder surgery occurred in a case described by Hynson et al.  ⁴After interscalene block, the patient was placed in the left lateral decubitus position and was lightly sedated. An arthroscopy pump was used to irrigate the joint with lactated Ringer's solution. After 1 h and 45 min, the patient became dyspneic and was unable to phonate. Severe edema of the operative side of the chest and neck were observed. Attempted ventilation by facemask failed, and the patient was intubated. Because of massive pharyngeal edema, a 7.0-mm ETT could not be passed, and a 6.0-mm tube was inserted instead. By the next day, the edema had significantly improved, and the patient's trachea was extubated.

In both of the cases described, a degree of alertness allowed the patient to complain of neck pressure or dyspnea. ^4,5Deeper degrees of sedation, such as in the present case, do not allow for such early verbal warnings that might avert the necessity of emergent ventilation or intubation.

Berjano et al.  ¹⁰reported a series of complications in arthroscopic shoulder surgery in which he noted four cases of severe edema involving the cervical region, out of a total of 141 cases performed. Surgery in these cases was performed in the lateral decubitus position. Of these four, one required reintubation after surgery and admission to the intensive care unit.

Factors that may underlie the accumulation of extra-articular edema include the use of an irrigation pump for infusion of fluid into the joint, especially at high pressures, ^5,9,11and the duration of surgery. ⁴The overall volume of irrigation fluid used is likely to contribute as well. Fluid escape is most common during arthroscopic acromioplasty, because the subacromial space is not encapsulated. ¹²In addition, fluid may escape through the insertion portals of the surgical instruments. ¹¹Hynson et al.  ⁴noted that patients’ neck circumferences increased up to 5 cm after even routine shoulder arthroscopies.

In sum, this is the first reported case of airway obstruction from fluid extravasation during shoulder arthroscopy in the beach-chair position. Airway management was complicated by marked edema, and LMA Unique  TM insertion followed by fiberscopic intubation was life saving. Measures that should be observed to prevent this potentially fatal complication include maintaining a light degree of sedation, restricting the duration of the procedure, and minimizing the arthroscopy pump pressures and amount of fluid used for joint irrigation. In addition, hourly evaluation of the degree of neck swelling can forewarn the occurrence of severe edema and allow cessation of the procedure and tracheal intubation if necessary.

References