Pain management after shoulder arthroplasty

 Pain Management After Shoulder Arthroplasty: A Systematic Review of Randomized Controlled Trials

These authors performed a systematic review of randomized controlled trials (RCTs) to evaluate the effect of analgesia methods on postoperative (1) pain, (2) opioid use, (3) length of stay (LOS), and (4) adverse events in patients undergoing TSA, reverse TSA, and hemiarthroplasty.

Eight studies (67%) included continuous interscalene block (CISB) with an indwelling

catheter, six studies (50%) included a single-injection interscalene block (ISB), five studies

(42%) included local infiltration with liposomal bupivacaine, four studies (33%) included local

infiltration with anesthetics other than liposomal bupivacaine, one study (8%) included brachial

plexus blocks other than ISB. 

ISB provided better pain relief than local infiltration in the immediate postoperative period (0-8 hours) as seen in 5/7 (71.4%) studies, but pain levels became similar subsequently. 

CISB may be superior to single-injection ISB for pain control at the 24-hour time point; however, a

greater number of adverse events and increased cost were seen with CISB.

No pain management modalities significantly impacted LOS.

The overall cost of single-injection block and continuous block can approach $1,500 and $1,850, respectively, if professional fees are included.

Complications seem with interscalene blocks include phrenic nerve palsy, dyspnea, and persistent distal neuropathy; complications after interscale blocks have been reported in up to 36% of cases. Rebound pain can be substantial when the block wears off 8-24 hours after surgery.  In some cases, rebound pain can lead to greater pain levels and increased narcotic requirement after interscalene block compared to local infiltration. While higher concentrations of an anesthetic such as ropivacaine may produce a more dense block, undesirable effects such as a more pronounced rebound effect, a prolonged motor blockade, and risk of neurotoxicity

Complications of continuous interscalene block are more frequent than for single shot blocks,  including  phrenic nerve block, hemidiaphragmatic palsy, dyspnea, dysphagia, infection, dislodgement, and catheter malposition. 

Comment: The conclusions of this review can be compared to the findings in some other recent publications:

Single-Shot Versus Continuous Interscalene Block for Postoperative Pain Control After Shoulder Arthroplasty: A Prospective Randomized Clinical Trial

In a randomized study, these authors compared continuous interscalene block (CIB) with single-shot interscalene block for postoperative control in 76 patients having shoulder arthroplasty.

Pain scores (P = 0.010) and opioid use (P = 0.003) on the first postoperative day were lower in the CIB group, but there was no difference in length of stay. Note that over half of the patients had a length of stay over one day.

Adverse events were more common in the CIB group; 10% of catheters pulled out prematurely. One patient required pacemaker implantation after syncopal episodes that may have been related to inadvertent intravascular injection.The authors point out that with plexus block anesthesia, the potential for serious complication remains and that centers with great experience in regional anesthesia have reported serious complications including pneumothorax and intravascular injection as well as transient and permanent postoperative loss of nerve function. 

They conclude that the benefits of CIB may not justify the complication rate and higher costs*.

*Note that the costs listed in this table do not include the professional fees for the anesthesiologist's time for performing either a single shot or a CIB.

There is no question that narcotic pain medications place patients at risk for nausea/vomiting, respiratory depression, constipation, falling, urinary retention, and confusion. However, as shown by these authors, plexus blocks have potentially serious risks as well.

To reduce these risks, we employ a multimodal approach without plexus blocks using preoperative education, Tylenol, Celebrex and Gabapentin. Assisted motion is started for all anatomic arthroplasties immediately after surgery in the recovery room. Patients have their PCA discontinued the evening of surgery and are almost always ready for discharge on the first morning after surgery.

With this "block-less" program our patients have minimal difficulty in starting their immediate postoperative range of motion exercises as is shown here for a 63 year old man on the morning after his total shoulder arthroplasty immediately prior to his discharge.

Our reasons for avoiding interscalene blocks for shoulder arthroplasty include (1) desire for documentation of neurological status immediately after surgery, (2) wanting to avoid having a flail unprotected arm as we start immediate postoperative motion exercises, (3) eliminating the risk of block-related neurologic or pulmonary complications, (4) avoiding phrenic nerve paresis with the attendant respiratory compromise, (5) eliminating the inconvenience of a failed block, (6) reducing the cost (professional and materials) associated with two different anesthetics (block + general), (7) avoiding the problem of acute rebound pain in the middle of the first postoperative night, and (8) the reluctance of some patients to have a needle placed in their neck.

Here is a bit more discussion regarding the issues with blocks:

Continuous versus single shot brachial plexus block and their relationship to discharge barriers and length of stay

These authors conducted a retrospective review of 697 patients undergoing upper extremity arthroplasty comparing the rate of complications and incidence of potential barriers to discharge and length of stay of patients receiving continuous vs. single-shot perineural brachial plexus block.

The complication rate was 12% (n=63) for the indwelling group and 17% (n=30) for the single-shot group.

The majority of complications were pulmonary, 72% attributable to oxygen desaturation. The indwelling catheter group had 1.61 times higher odds (95% confidence interval, 1.07-2.42; P = .023) of exhibiting any potential barrier to discharge and exhibited a longer length of stay (P = .002).

Our thoughts on interscalene block anesthetics can be viewed here:

Why not just do an interscalene nerve block anesthetic?

and here

The types and severity of complications associated with interscalene brachial plexus block anesthesia: local and national evidence.

Here are some videos that are of shoulder interest

Shoulder arthritis - what you need to know (see this link).

How to x-ray the shoulder (see this link).

The ream and run procedure (see this link).

The total shoulder arthroplasty (see this link).

The cuff tear arthropathy arthroplasty (see this link).

The reverse total shoulder arthroplasty (see this link).

The smooth and move procedure for irreparable rotator cuff tears (see this link).

Shoulder rehabilitation exercises (see this link).