During the past decade, there has been explosive growth in the trend to provide cost-effective care in the practice of medicine. The worldwide growth of anesthesia for ambulatory surgery is an increasingly important part of this trend. Currently, more than 60% of all elective surgeries in the United States are done on an outpatient basis, 5 and this is likely to increase in response to economic pressures in the healthcare market. In no specialty is this more prevalent than orthopaedics. Although reconstruction of the knee using arthroscopic techniques has facilitated outpatient care for ligament reconstruction and meniscus repair, arthroscopic shoulder reconstruction only recently has become a common option.
Ambulatory surgery offers a wide variety of advantages to all parties including patients, surgeons, insurance companies, and surgery facilities. Patients and their relatives experience less disruption to their personal lives and a more rapid return to daily activities. Patients are able to recover at home in familiar surroundings thus providing an additional psychosocial benefit. There is a reduced risk of nosocomial complications such as wound infections, deep vein thrombosis, pulmonary embolism, ileus, and pneumonia.
The cost of surgery on an ambulatory basis has been estimated to be 25% to 75% less than a similar inpatient procedure, in part because of less preoperative testing, lower ancillary services required, reduced demand for medications postoperatively, and a more efficient use of equipment and operating rooms. With the recent improvements in surgical and anesthetic techniques, patient acceptance and satisfaction with ambulatory surgery has increased.
Recently, a study compared arthroscopic and open repair of shoulder instability with the former being done on an outpatient basis and the latter being done as an inpatient procedure. The conclusions of this study were clear. It was more cost-effective to do this procedure arthroscopically and send the patient home after surgery. 2
Regional Interscalene Anesthesia
The technique of brachial plexus block for arthroscopic shoulder reconstruction is a relatively recent advance in anesthesia for ambulatory surgery. In 1970, Winnie 19 popularized brachial plexus blockade by the interscalene approach; however, in 1925, Halsted 8 used cocaine to block separate exposed nerve roots of the brachial plexus. The interscalene approach to the brachial plexus has been used for more than three decades and has become increasingly popular for outpatient shoulder surgery. The brachial plexus block offers several advantages over general anesthesia. It eliminates the need for tracheal intubation, which can be challenging in patients with arthritis. The use of longer lasting local anesthetics can provide for significant duration of postoperative analgesia, and decreased use of postoperative oral narcotic medications, thus facilitating earlier patient discharge. Complications also can occur with regional anesthetic techniques in the areas of block performance, local anesthetic toxicity, and nerve injury. The current authors will discuss their approach to anesthesia and recovery for outpatient shoulder reconstruction.
Indications and Contraindications
A clinical study showing distribution of sensory and motor blockade indicated that interscalene block is best applied to surgery of the shoulder and proximal upper extremity. 7 Distribution of local anesthetic after interscalene block usually is limited to the brachial plexus above the clavicle. In addition, the lower roots of the brachial plexus frequently are missed by the interscalene approach. 10 Absence of blockade in these components makes it unsatisfactory for surgeries involving the elbow and sites distal to the elbow. 12,17 Therefore, the authors reserve the interscalene block for patients undergoing surgery of the shoulder and proximal upper extremity.
One of the main indications for interscalene block is patient preference to general anesthesia and tracheal intubation. Some patients prefer to be awake with minimal sedation for the procedure. Others prefer to be asleep for the procedure but want the added benefit of prolonged postoperative analgesia that regional anesthesia can provide. In addition, in the authors’ experience, early recovery and discharge home are improved significantly when patients chose a regional anesthetic approach as opposed to general anesthesia. As always, adequacy of the block is a prerequisite to the regional technique, and equipment for endotracheal intubation and positive pressure ventilation always must be present. 4,9
Contraindications to interscalene brachial plexus block include coagulopathy, infection at the injection site, and preexisting pathologic disorders involving the brachial plexus. In addition, the block is contraindicated in patients with moderate to severe alterations to respiratory function. Interscalene block results in ipsilateral hemidiaphragmatic paresis, which will decrease the forced vital capacity by as much as 30% on average. 16 For patients who may not tolerate this decrease in forced vital capacity, including patients with severe chronic obstructed pulmonary disease, contralateral pneumonectomy, pneumothorax, phrenic nerve palsy, or ankylosing spondylysis, this block is contraindicated. 14 Relative contraindications include extremes of age, psychiatric disease, and intraoperative lateral positioning, which may diminish functional residual capacity in the down lung.
Specific advantages of regional interscalene anesthesia are for arthroscopic repair of shoulder instability and arthroscopic release of refractory adhesive capsulitis of the shoulder. In the former, regional anesthesia facilitates an efficient arthroscopic Bankart repair, which then allows the patient to leave the operating room and progress quickly to a point where they are comfortable to go home. In the latter case, interscalene block anesthesia with an indewelling interscalene catheter allows for prolonged analgesia during the postoperative period. These patients are admitted to the hospital for 48 hours for aggressive physical therapy, and the authors have found regional anesthesia and analgesia greatly reduces the need for narcotics and facilitates rehabilitation therapy.
In the authors’ institution, administration of the blocks is done in the preoperative holding area. This area accommodates as many as eight patients. Each patient slot has curtains for privacy, and is equipped with at least oxygen, suction, a pulse oximeter, and automatic blood pressure cuff. Electrocardiogram and emergency equipment is always readily available to each patient slot. Patients are placed in the supine position, head flat, with a pulse oximeter for monitoring and are sedated using midazolam (1–2 mg intravenously), and fentanyl (50–100 μg intravenously). The patient’s head is rotated 30° to 45° in the opposite direction. Blocks usually are done by residents in anesthesia and are assisted by attending staff anesthesiologists.
Palpation of the interscalene groove is the first step in doing this block. At the level of the cricoid cartilage, the external jugular vein is located; palpation slightly anterior to this point very often locates the interscalene groove. If the groove is not apparent, the patient is asked to lift his or her head in this position, and the posterior border of the sternocleidomastoid muscle is identified and the palpating finger is advanced beneath it. With the patient’s neck relaxed, the hand is swept laterally, first encountering the belly of the anterior scalene muscle, and finally the groove between the anterior scalene muscle and the middle scalene muscle. The interscalene groove often is much subtler than the large groove behind the sternocleidomastoid and medial to the anterior scalene. 18 After the neck is washed with a surgical wash solution the skin is injected with local anesthetic raising a small intradermal skin wheal, being careful not to introduce the local anesthetic any deeper lest it interfere with nerve stimulator function. Starting with approximately 1 mA on the nerve stimulator, a 50-mm insulated needle (connected to the nerve stimulator) is introduced (avoiding the external jugular vein) and directed nearly perpendicular to the skin on all planes, with very slight medial and caudal deviation, until a motor-evoked response is elicited. The interscalene groove usually is superficial, and the operator need not advance the needle more than 35 to 40 mm. A motor response in the deltoid or biceps muscles must be sought. Shoulder elevation or shoulder blade movement is not acceptable because this may represent stimulation of the spinal accessory nerve, which is located outside the groove. When seen, the needle is redirected in a more anterior direction. When the needle is placed too anterior, stimulation of the phrenic nerve is evidenced by ipsilateral hemidiaphragmatic motion. With correct placement the superior roots (C5 and C6) are most likely to be stimulated. In the authors’ institution, the presence of such stimulation with a stimulator current of approximately 0.3 mA correlates well (> 95%) with a proximal upper extremity block. Successful block is seen by the patients’ loss of ability to elevate the arm (deltoid and biceps weakness or block).
Proximal pressure on the sheath during injection can facilitate a more distal spread of local anesthetic and may speed the onset of action. Using a small needle (50-mm) minimizes patient discomfort, and maximizes patient safety when teaching residents.
Side Effects and Complications
Before placement of interscalene blocks, patients are informed in detail of what to expect regarding side effects. Most commonly mild chest heaviness, Horner’s Syndrome, and recurrent laryngeal nerve block are observed. However, proximity of the vertebral artery makes intraarterial injection possible with rapid progression to grand mal seizure after small amounts of local anesthetic are injected. Venous injection and rapid absorption in the highly vascular neck can result in less rapid central nervous system excitation phenomena. The neural foramina can be reached, and massive epidural, subarachnoid, or subdural injection can occur. Pneumothorax is possible and more likely with chronic obstructive pulmonary disease because of the superior displacement of the apex of the lung. 6
Stellate ganglion block results in Horner’s syndrome (myosis, ptosis, and anhidrosis) in more than 50% of interscalene blocks. Horner’s syndrome is benign and usually resolves before the offset of the block. This side effect seems to be more concerning to patients’ family members than to the patients themselves.
Recurrent laryngeal nerve block (< 10%) leads to hoarseness and a weak voice. Another possibility of why patients become hoarse is the vasodilation of the laryngeal and arytenoid blood vessels causing an alteration in laryngeal mechanics. Whatever the cause, this side effect usually is of very short duration. The authors observed that patients have their voice back within 3 to 5 hours after surgery.
Phrenic nerve block (as much as 100%) leads to a feeling of heaviness on the ipsilateral chest. Hemidiaphragmatic paresis from interscalene block is associated with decreases in routine pulmonary function test values of approximately 30%. These changes occur quickly after the block is done and essentially are maximal and complete 15 minutes after local anesthetic injection. Despite these large pulmonary function test changes, interscalene block only rarely is associated with dyspnea. If dyspnea occurs, the patient should be reassured, and usually a sitting position will ameliorate these pulmonary function test changes. When these patients are placed in the sitting position they tend to feel better. Shoulder surgery done with the patient in the beach chair or sitting position is ideal for interscalene block because it results in more optimal diaphragmatic geometry and mechanics. Equipment to administer positive pressure ventilation or intubation should be readily available. 13,15
Among the past 1000 interscalene blocks, the authors have seen three cases of unintentional epidural block. All three patients were hemodynamically stable, without any evidence of respiratory compromise and completed their surgeries, awake, without any special intervention other than reassurance. On resolution of the epidural block, all patients remained with dense, ipsilateral brachial plexus block. All three patients were satisfied with the experience and stated they would choose interscalene block again.
Until recently, recovery from anesthesia in the United States was deemed acceptable if the patient was transferred safely from the recovery room to the general surgical ward of the hospital. With the luxury of unlimited reimbursement from third party payers, additional recovery, even from a simple surgical procedure, might take days. Today, as government, industry, and third party payers continue to scrutinize the practice of medicine in America, the luxury of a prolonged recovery seems to be extinct.
Currently, the usual recovery protocol for outpatients receiving anesthesia is the criteria driven progression from the operating room to the postanesthesia care unit and then to the Phase 2 postanesthesia care unit (recovery lounge or step-down unit) followed by discharge to home when the patient has met the discharge criteria. The use of regional anesthetic techniques and the availability of rapid and shorter-acting intravenous and volatile anesthetics has facilitated early recovery in the ambulatory setting. Therefore, patients can be completely awake and oriented, breathing comfortably, with stable vital signs in the operating room shortly after ambulatory surgical procedures, even after general anesthesia. If the criteria used to discharge patients from the postanesthesia care unit are met in the operating room, it would be appropriate to consider bypassing the postanesthesia care unit and transferring the patient directly to the Phase 2 postanesthesia care unit. This process is known as fast-tracking after ambulatory surgery. In ambulatory surgery, anesthetic techniques enabling rapid recovery without side effects are of utmost importance. 1
At the authors’ institution, a formal fast-track protocol was designed with input from the departments of anesthesia, nursing, and surgery. All patients receiving general anesthesia are monitored with the BIS EEG monitor (Aspect Medical Systems, Newton, MA) for titration of anesthetic concentration. For patients receiving regional anesthesia, any desired conscious sedation is titrated to effect. On completion of the surgical procedure, the majority of patients who had shoulder surgery (>75%) are fast-tracked, by wheelchair, to the Phase 2 postanesthesia care unit recovery lounge. They are offered something to eat and drink, given postoperative instructions, allowed to dress, and usually ready for discharge home (with an escort) within 30 to 45 minutes. Any patient who required general anesthesia and does not meet postanesthesia care unit fast-track criteria (Table 1) is taken to the postanesthesia care unit for recovery by regular (modified Aldrete score) protocol. 3,11
Along with postoperative surgical instructions, patients are given instructions pertaining to the peripheral nerve block (Appendix 1). Patients are allowed to go home with a numb arm in a protective sling, and given a telephone number to call should any questions or problems arise.
Interscalene Anesthesia for Instability Repair: The Surgeon’s Perspective
At the authors’ institution, approximately 90% of all patients undergoing arthroscopic Bankart repair or repair of a torn superior labrum are treated with regional interscalene anesthesia and minimal intraoperative sedation. Advantages are not only prolonged pain relief for patients and reduced side effects of general anesthesia, but also efficient daily patient treatment. With sufficient staffing, it is possible for the anesthesiologist to place an interscalene block in the next patient in the preoperative holding area while surgery is being completed in another patient. This allows the subsequent patient to be brought into the operating room and positioned quickly without need for placement of the block or induction of general anesthesia. Similarly, there is no need to await reversal of general anesthesia after the procedure.
Although regional anesthesia is feasible if the patient is in a lateral decubitus position, it is more efficient to do so if the patient is placed in a sitting beach chair position. In addition, patients may complain of dyspnea if they are placed in a lateral decubitus position when they have a hemidiaphragm paralysis on their upside.
In a recent comparison of 64 consecutive patients undergoing arthroscopic or open Bankart repair the authors observed several findings. First, all of the patients undergoing an open Bankart repair had general anesthesia compared with all patients undergoing arthroscopic repair who had regional anesthesia. The overall operating room time (in room to out of room) was 30 minutes less for patients undergoing the arthroscopic procedure. Although operating room costs were greater for arthroscopic repair versus open repair, this was attributable to implants, not to anesthesia costs. Finally, because all of the patients who underwent arthroscopic repair were discharged on the day of surgery, compared with the patients who underwent open repair and stayed overnight, the cost savings for the former amounted to approximately $2000 per patient. 2
Postoperative Surgical and Anesthesia Instructions
SDCU Patient Instructions
You have received this paper because your anesthesiologist gave you a form of regional anesthesia as part of your care. The information below is important for your safety and comfort.
Simply put, this means that a local anesthetic (similar to that which dentists use) was used to numb up a part of your body. Routinely, we send patients home with that portion of their body still anesthetized (numb). The length of time that the area will remain numb is highly variable: it depends on a large number of factors and is difficult to predict.
The part of your body that was operated on may remain numb for many hours. Pain is a protective function of the body. Though its loss is comforting, it does place you at risk for accidental injury. It is during this extended painless period that you must be most careful. It is surprisingly easy to ignore a part of the body that is asleep. Extra vigilance is required to prevent an accidental injury. For example, special care should be used:
- when around hot/burning objects and liquids,
- walking through doors and around the house, sitting in chairs.
- If you fall asleep, someone should check on you to make sure you don’t roll and sleep on that part of your body.
A little extra care will result in a very uneventful and safe recovery.
As mentioned earlier, the effect of the local anesthetic lasts a variable amount of time (but never longer than one day). A large number of things affect the duration making it impossible to accurately estimate the length of time the numbness will last. The beneficial part of this is that the discomfort from the surgery is not felt until the anesthetic wears off. The effect of the local anesthetic does not end abruptly: it wears off over a brief period of time. You will notice subtle changes (i.e. sensations like tingling or pins and needles or return of muscle strength) in the affected area before sensation returns completely. THIS is an important time (see below). Your surgeon has given you a prescription for pain medications (pills). You should get this prescription filled before or shortly after leaving the hospital. When the local anesthesia starts to wear off, you will want to start your pain medications IMMEDIATELY. In fact, you should start taking the pain medications BEFORE you actually begin to experience pain (it IS safe to do this). After taking the pills, it takes a little while for them to start working ... meanwhile, the local continues to wear off. You WILL be sore after your surgery but experience has taught us that staying ahead of the pain will minimize your discomfort. Once you fall behind, it is often difficult to get comfortable again.
Dr. Warner’s Postoperative Instructions After Arthroscopic Ligament Repair
- Keep your arm in your sling for the first 24 hours.
- Maintain compression ice pack on your shoulder for the first 24 hours.
- After 48 hours you can have your dressing removed and replace Bandaids over your small incisions.
- You may go in a shower after 48 hours, but do not get your shoulder wet and keep your arm at your side.
- Please call the office to arrange for an appointment next week.
- Please call the office for signs of redness, increased swelling, drainage, or increasing pain.
- You may bend your elbow to feed yourself or type on a computer.
- Do not actively move your arm.
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2. Barber FA, Click SD, Weiderman CA: Arthroscopic or open Bankart procedures: What are the costs? Arthroscopy 14:671–674, 1998.
3. Bell S, Hill N: Factors facilitating PACU bypass in ambulatory surgery. Anesthesiology 87:A34, 1997.
4. Blanchard J, Rarnamurthy S: Indications for Brachial Plexus Blockade. In Benurnof JL (ed). Clinical Procedures in Anesthesia and Intensive Care: Brachial Plexus. Philadelphia, JB Lippincott 748–788, 1992.
5. Centers for Disease Control: Vital and Health Statistics, Ambulatory and Inpatient Procedures in the United States. Washington, DC, Centers for Disease Control 1996.
6. Conn R, Cofield R, Byer D, et al: Interscalene block anesthesia for shoulder surgery. Clin Orthop 216: 94–98, 1987.
7. Davis W, Lennon R, Wedel D: Brachial plexus anesthesia for outpatient surgical procedures on an upper extremity. Mayo Clin Proc 66: 470–473, 1991.
8. Halsted WS: Surgical Papers. In Burket WC (ed). Baltimore, Johns Hopkins Press 167–176, 1925.
9. Kulenkampff D, Persy MA: Brachial plexus anesthesia: Its indications, technics and dangers. Ann Surg 87:883–891, 1928.
10. Lanz F, Theiss D, Jankovic D: The extent of blockade following various techniques of brachial plexus block. Anesth Analg 62:55–58, 1983.
11. Mayfield J, Quigley J: BIS monitoring reduces Phase 1 PACU admissions in an ambulatory surgical unit. Anesthesiology 91:A28, 1999.
12. Partridge B, Katz J, Benirschke K: Functional anatomy of the brachial plexus sheath: Implications for anesthesia. Anesthesiology 66: 743–747, 1987
13. Pere P, Pitkinen M, Rosenberg PH, et al: Effect of continuous interscalene brachial plexus block on diaphragm motion and on ventilatory function. Acta Anaesthesiol Scand 36:53–57, 1992.
14. Unney WE, Talts KK, Sharrock NE: One hundred percent incidence of hemidiaphragm, paresis associated with interscalene brachial plexus anesthesia as diagnosed by ultrasonography. Anesth Analg 72:498–503, 1991.
15. Urmey WF, Gloeggler PJ: Pulmonary function changes during interscalene block: Effects of decreasing local anesthetic injection volume. Reg Anesth 18:244–249, 1993.
16. Urmey WF, McDonald M: Hemidiaphragmatic paresis during interscalene brachial plexus block: Effects on pulmonary function and chest wall mechanics. Anesth Analg 74:352–357, 1992.
17. Winnie A: Interscalene Technique of Brachial Plexus Block. In Winnie A (ed). Plexus Anesthesia: Perivascular Techniques of Brachial Plexus Block. Philadelphia, WB Saunders 167–186, 1990.
18. Winnie AP: An “immobile needle” for nerve blocks. Anesthesiology 31:577–578, 1969.
19. Winnie AP: Interscalene brachial plexus block. Anesth Analg 49:455–66, 1970.
Jon J. P. Warner, MD; and Brian J. Cole, MD, Guest Editors