What to Expect From a Nerve Block for Shoulder Surgery

A nerve block for shoulder surgery numbs the nerves that supply your shoulder, arm, and upper chest, giving you hours of near-complete pain relief that starts before you even wake up from the procedure. The most common type is called an interscalene brachial plexus block, where an anesthetic is injected near a bundle of nerves on the side of your neck. It dramatically cuts the amount of pain medication you need, shortens your time in the recovery room, and often lets you go home the same day with your shoulder feeling almost nothing. But the block does wear off, and what happens next is something worth preparing for.

How the Block Is Placed and What You Feel

Before your surgery begins, an anesthesiologist or sometimes the surgeon will position you so they can access the side of your neck near the collarbone. Using an ultrasound probe, they locate the nerve roots that run to your shoulder. Ultrasound guidance lets the clinician watch the needle tip in real time, which reduces the risk of accidentally puncturing a blood vessel, hitting the lung, or injecting into the nerve itself. In a large case series of over 1,300 shoulder surgeries with ultrasound-guided blocks performed by an orthopedic surgeon, no major complications like seizures, pneumothorax, or lasting nerve injury were reported.¹

You might feel pressure or a brief sting from the local numbing agent used on your skin before the deeper injection. Some people feel a muscle twitch in their arm or shoulder as the needle nears the nerve roots. Within minutes, warmth and heaviness spread through your shoulder and arm. Your arm may feel completely limp, and you will probably lose the ability to grip or lift it until the block resolves. This temporary paralysis can be unsettling if you are not expecting it, but it is a normal part of the process and means the block is working.

Pain Relief During and After Surgery

The block’s primary job is to keep you comfortable during surgery and in the critical first hours afterward, when surgical pain tends to be at its worst. For many procedures, the block works so well that the surgeon can operate with much lighter general anesthesia or even sedation alone. In practical terms, this translates to less narcotic medication flowing through your system.

A retrospective study of shoulder arthroscopy patients found that those who received an interscalene block before surgery used roughly half the opioids during the operation compared with patients who did not get a block.² After surgery, the difference can be even more striking: one study reported that about 61% of patients who received a block needed no opioids at all postoperatively, compared with less than 1% of patients without a block.³ Fewer opioids also means less grogginess, less constipation, and a clearer head when you are trying to follow discharge instructions.

Getting Home Faster

One of the most tangible benefits of a nerve block is how quickly you can leave. A trial comparing nerve block anesthesia with general anesthesia for outpatient rotator cuff surgery found that patients who received a block bypassed the recovery room more often, reported less pain, walked sooner, and were ready to go home in about two hours on average, compared with nearly five hours for those under general anesthesia alone. None of the block patients had an unplanned hospital admission, whereas several in the general anesthesia group did.⁴ Satisfaction scores were higher in the block group as well. If you have been told your shoulder surgery is outpatient, the nerve block is a big part of what makes that possible.

How Long the Numbness Lasts

A standard single-shot interscalene block provides strong pain relief for somewhere in the range of 8 to 18 hours, depending on the drug used, any additives mixed in, and your individual metabolism. During this window, most people describe their shoulder and arm as feeling heavy, tingly, or absent altogether. You can expect your fingers to be clumsy or numb, and you should not attempt to use the affected arm for anything requiring coordination.

For larger surgeries like shoulder replacement, your anesthesiologist may offer a continuous catheter instead. This is a thin tube left near the nerve bundle after the initial injection, connected to a small pump that delivers a steady drip of local anesthetic. Continuous catheters extend the pain-relief window well past 48 hours and have been shown to reduce opioid use and improve pain scores on the first postoperative day compared with a single shot.⁵ A meta-analysis confirmed that the continuous approach provides better pain control both at rest and during movement beyond the 48-hour mark, along with higher patient satisfaction and less nausea and vomiting.⁶

The trade-off is that a catheter requires more aftercare. You go home with a small pump taped to your skin, and about 16% of patients in one randomized trial experienced catheter dislodgement or leakage before the infusion was finished.⁷ That same trial found that a single injection of a long-acting formulation of bupivacaine provided equivalent pain relief through three days, with no catheter to worry about and costs about 28% lower.

Rebound Pain When the Block Wears Off

This is probably the most important thing to prepare for. While the block is active, you feel little to no pain. When it fades, the contrast can be jarring. Clinicians call this “rebound pain,” and it can affect up to roughly 40% of patients who receive a nerve block for surgery.⁸ Rebound pain is characterized by a jump from minimal discomfort while the block is working to sharp, significant pain within the first day after the injection. It tends to spike in the middle of the night for many patients whose block was placed in the morning, which makes it especially unpleasant.

The best strategy is preemptive: start taking your prescribed oral pain medications before the block wears off, not after. Most anesthesiologists and surgeons will send you home with specific instructions on timing. Common approaches include scheduled acetaminophen and an anti-inflammatory drug, with an opioid available if needed. A clinical trial testing whether adding dexamethasone or clonidine to the block injection could prevent rebound pain found that roughly a quarter to a third of patients in the treatment groups still experienced it, compared with about 41% in the control group, though the differences did not reach statistical significance.⁹ In other words, rebound pain remains a real challenge even with the best available adjuncts, and planning your oral pain medication schedule around the expected fade of the block is still your most reliable defense.

Common Side Effects You Should Know About

The interscalene block targets nerves that sit near other important structures, and some temporary side effects are nearly unavoidable at standard doses. The most common is weakening or temporary paralysis of the diaphragm on the same side as the block. The phrenic nerve, which controls half of your diaphragm, runs close to the brachial plexus at the level where the injection is given. At traditional volumes, the rate of some degree of diaphragmatic paresis is high enough that researchers consider it a known limitation rather than a rare complication.¹⁰ For a person with two healthy lungs, this usually feels like mild shortness of breath or a sensation of not being able to take a full, deep breath. It resolves as the block wears off.

Some people also experience a hoarse voice or a feeling of something in their throat, caused by the anesthetic spreading to the recurrent laryngeal nerve. Hoarseness is typically mild and goes away on its own. In extremely rare circumstances, if the other recurrent laryngeal nerve was already damaged from a prior condition, the block can temporarily affect both sides and cause a more dramatic loss of voice. A published case report described a patient who lost her voice entirely after a block because she had an undiagnosed injury to the nerve on the opposite side.¹¹ This is exceptionally uncommon, but it is worth mentioning if you have a history of thyroid surgery, neck radiation, or other conditions that could affect your vocal cord nerves.

Other temporary effects can include a drooping eyelid on the same side (Horner syndrome, caused by anesthetic reaching the sympathetic chain), a warm or flushed feeling on one side of the face, and a sense that one nostril is stuffed up. All of these resolve when the block wears off.

Who Should Avoid a Standard Interscalene Block

Because of the diaphragm effect, the standard interscalene block is relatively contraindicated for people with significant lung disease. If you have moderate to severe COPD, are dependent on one lung, or have conditions that already limit your breathing capacity, your anesthesiologist will probably suggest an alternative approach.¹² People with pre-existing phrenic nerve palsy on the opposite side are also poor candidates, since blocking the remaining functional diaphragm could seriously compromise breathing.

Patients on blood thinners need their clotting status reviewed before a nerve block, as injection near major blood vessels carries a small bleeding risk. And if you have had a previous allergic reaction to local anesthetics, that obviously changes the plan. These are discussions your anesthesia team will have with you in the pre-operative appointment.

Newer Techniques That Spare the Diaphragm

The diaphragm issue has pushed researchers to develop alternative blocks that numb the shoulder while leaving the phrenic nerve alone. Several approaches are gaining traction. Costoclavicular blocks, which target the brachial plexus lower down near the collarbone, have shown comparable pain relief to the interscalene block with a reported 0% incidence of diaphragmatic dysfunction in cumulative evidence to date.¹³ Anterior suprascapular nerve blocks can provide surgical-level anesthesia as well, though their diaphragm-sparing profile has not been formally quantified yet.

A newer option called the sub-omohyoid fascial plane block targets the suprascapular nerve and nearby structures through a tissue plane beneath a small muscle in the neck. Early evidence suggests it may provide meaningful pain relief with less phrenic nerve exposure, but the research is still limited and inconsistent in how it defines and measures outcomes.¹⁴ Another approach combines a reduced-volume interscalene injection with a supplementary block of the superior trunk, which has been shown to achieve adequate surgical anesthesia with less complete diaphragm paralysis.¹⁵ If you have any respiratory concerns, ask your anesthesiologist specifically whether a diaphragm-sparing technique is available and appropriate for your surgery.

Extending the Block With Additives and Long-Acting Formulations

Anesthesiologists have several tools to make the pain relief from a single injection last longer. The most studied additive is dexamethasone, a steroid that can be mixed into the injection or given intravenously alongside it. A meta-analysis with trial sequential analysis found that adding dexamethasone directly to the nerve block extended the duration of pain relief by an average of about two hours compared with giving the same drug through an IV, though the quality of the evidence was rated low because of inconsistency across studies and possible publication bias.¹⁶ A separate meta-analysis of seven trials supported the same direction, finding that adding dexamethasone to the block also lowered pain scores at 12 hours after surgery.¹⁷

Liposomal bupivacaine is a formulation that encases the anesthetic in tiny fat-based particles that release the drug slowly over days rather than hours. A systematic review and meta-analysis found that single-injection nerve blocks using liposomal bupivacaine resulted in lower pain levels and less opioid use across the first, second, and third days after surgery compared with other single-injection blocks and even compared with continuous catheter infusions.¹⁸ Co-administering standard bupivacaine with liposomal bupivacaine also appears to improve pain scores through the second postoperative day and reduce opioid consumption through the third day.¹⁹

For patients who want the extended relief of a catheter without the catheter’s hassle, liposomal bupivacaine is an increasingly popular middle path. It is not available at every institution, and cost can vary, but it is worth asking about.

Using Alternative Nerve Targets for Long-Lasting Relief

Beyond the interscalene approach, some centers offer blocks that target individual nerves supplying the shoulder rather than the entire brachial plexus. A randomized trial found that using liposomal bupivacaine for a combined suprascapular nerve and axillary nerve block provided long-term postoperative pain relief that was comparable to a traditional interscalene block, with fewer episodes of diaphragm dysfunction.²⁰ This combination targets the two nerves most responsible for shoulder sensation while largely avoiding the phrenic nerve. It is a good example of how the field is moving toward more selective blocks that deliver the benefits without the respiratory trade-off.

The Block and Physical Therapy

If you are having shoulder surgery, early physical therapy is usually part of the plan. The nerve block creates a paradox here. On the one hand, therapists overwhelmingly agree that blocks improve a patient’s pain after joint surgery. On the other hand, a survey of physical therapists found that the vast majority felt nerve blocks made it harder for patients to participate in therapy sessions and made their own job more difficult, because patients cannot feel or move the limb normally while the block is active.²¹

In practice, this usually matters most in the first 24 hours. If you are having inpatient surgery with a continuous catheter, your therapy team may time sessions for when the block is at a lower dose, or focus on passive range-of-motion exercises that do not require your active muscle control. For outpatient procedures with a single-shot block, your first therapy session is typically scheduled a day or more after surgery, by which point the block has worn off. The key thing to remember is that while the block is working, your arm has no protective pain feedback. Do not try to test your range of motion or move your arm in ways that your surgeon has not cleared, even if it does not hurt, because you could damage the surgical repair without feeling it.

What to Ask Your Anesthesiologist

If a nerve block is offered before your shoulder surgery, a few questions can help you prepare for the experience and make informed choices. Ask whether you will receive a single shot or a continuous catheter, and why that choice was made for your specific procedure. Ask what time of day the block will likely wear off, so you can plan your oral medication schedule accordingly. If you have any lung or breathing issues, ask whether a diaphragm-sparing alternative is possible. Ask whether dexamethasone or liposomal bupivacaine will be used to extend the block’s duration, and what your backup pain plan looks like once the numbness fades. Finally, ask what sensations are normal as the block resolves. Tingling, pins-and-needles, and a gradual return of heaviness followed by pain are all expected. Persistent numbness or weakness beyond 48 to 72 hours after a single-shot block, on the other hand, should prompt a call to your surgeon’s office.