27.2 Closed Reduction, Hand and Foot Procedures & Intravenous Regional (Bier) Block
Key Takeaways
- Bupivacaine is absolutely contraindicated for intravenous regional anesthesia because cuff failure delivers a bolus to the heart producing refractory cardiotoxicity; preservative-free 0.5 percent lidocaine is used instead.
- The Bier block cuff is never deflated before 20 to 25 minutes, and deflation is then cycled 10 seconds down and 1 minute up to stagger the systemic bolus.
- Patients presenting for closed reduction are treated as full stomachs regardless of stated fasting time, because injury, pain, and opioids all delay gastric emptying.
- The ankle block requires five nerves: posterior tibial, sural, deep peroneal, superficial peroneal, and saphenous, of which only the saphenous arises from the femoral nerve.
- Capnography is mandatory during moderate and deep procedural sedation because unrecognized hypoventilation is the leading serious adverse event.
Why This Topic Matters on the NCE
Domain IV.A.8 names closed reduction and procedures of the hand and foot as distinct sub-topics, and Domain III.I.2 names infiltration among the local and regional techniques. These are short cases in unfamiliar locations, often on unfasted patients, and they include a block with the strictest safety rules of any regional technique.
1. Closed Reduction and Manipulation Under Anesthesia
The setting
Closed reduction of a fracture or dislocation is frequently done urgently in the emergency department, a procedure suite, or the operating room. The recurring features:
- The patient is rarely fasted. An injury interrupts gastric emptying, and pain and opioids delay it further, so the "6 hours since last meal" calculation is unreliable after trauma. The stomach should be assumed non-empty regardless of the elapsed interval.
- The procedure is intensely stimulating but very brief — often 2 to 5 minutes — and analgesia is barely needed once reduction is achieved. Anesthetic depth must therefore rise and fall quickly.
- The location may be remote, with all the ASA non-operating-room requirements applying.
Technique options
| Approach | Comments |
|---|---|
| Procedural sedation | Propofol with or without a small dose of ketamine, or ketamine alone in children. Etomidate is an alternative where cardiovascular reserve is limited |
| Ketamine | 1 to 2 mg/kg IV in children preserves airway reflexes and respiratory drive better than propofol; emergence phenomena are far less common in children than adults, and can be reduced with a small benzodiazepine dose in adults |
| Nitrous oxide | Useful adjunct in cooperative patients |
| Hematoma block | Direct injection of local anesthetic into the fracture hematoma, typically for distal radius fractures. Simple and avoids sedation, but provides incomplete analgesia and carries an infection concern |
| Regional block | Brachial plexus or ankle block; excellent for the cooperative patient and provides postoperative analgesia |
| General anesthesia | For failed sedation, uncooperative patients, and complex reductions |
Capnography is mandatory for any moderate or deep sedation, together with the full ASA monitoring standard, supplemental oxygen, suction, and immediate airway rescue equipment. The most common serious adverse event in procedural sedation is unrecognized hypoventilation.
Manipulation under anesthesia
Performed to break down adhesions after joint stiffness, most often the knee after arthroplasty or the shoulder in adhesive capsulitis. The forces applied are substantial and periprosthetic or osteoporotic fracture is a real risk, so profound muscle relaxation and controlled positioning matter.
2. Hand, Wrist, Foot and Ankle Procedures
These are ideal regional anesthesia cases: short, superficial, distal, and painful afterward.
Wrist block
Three nerves, all readily accessible:
| Nerve | Landmark |
|---|---|
| Median | Between the tendons of palmaris longus and flexor carpi radialis, at the proximal wrist crease |
| Ulnar | Deep to the flexor carpi ulnaris tendon, medial to the ulnar artery |
| Radial (superficial branch) | Subcutaneous field block across the dorsolateral wrist, since the nerve has already divided into terminal branches |
Digital block
Local anesthetic placed at the base of the digit blocking the two dorsal and two palmar digital nerves.
The traditional teaching that epinephrine must never be used in a digit has been substantially revised — large case series have not demonstrated digital necrosis with commercially prepared lidocaine with epinephrine, and epinephrine improves the field and prolongs the block. However, caution remains appropriate in patients with severe peripheral vascular disease, Raynaud phenomenon, or an already compromised digit, and phentolamine is the reversal agent if vasospasm is suspected. Avoid a circumferential ring of high-volume injection, which can cause mechanical compression regardless of epinephrine.
Ankle block
Five nerves, and the exam expects all five:
| Nerve | Origin | Location |
|---|---|---|
| Posterior tibial | Tibial | Posterior to the medial malleolus, behind the posterior tibial artery. The most important — supplies the sole |
| Sural | Tibial | Between the lateral malleolus and the Achilles tendon |
| Deep peroneal | Common peroneal | Between the extensor hallucis longus and tibialis anterior tendons, lateral to the dorsalis pedis artery. Supplies the first web space |
| Superficial peroneal | Common peroneal | Subcutaneous field block across the anterior ankle |
| Saphenous | Femoral | Anterior to the medial malleolus. The only one that is not a branch of the sciatic nerve |
Avoid epinephrine and avoid circumferential infiltration at the ankle in patients with compromised perfusion.
3. Intravenous Regional Anesthesia (Bier Block)
Described by August Bier in 1908, this is the technique with the tightest safety envelope in regional anesthesia, because the entire local anesthetic dose sits in an isolated limb behind a cuff that could fail at any moment.
Technique
- Place a small intravenous cannula distally in the operative limb and a separate cannula in the opposite arm.
- Exsanguinate the limb with an Esmarch bandage, or by elevation for 2 to 3 minutes if the limb is too painful to wrap.
- Inflate the proximal cuff of a dual (double) cuff tourniquet to roughly 100 mmHg above systolic pressure, and confirm loss of the distal pulse.
- Inject preservative-free lidocaine 0.5 percent, approximately 40 to 50 mL (up to about 3 mg/kg) for the upper limb.
- Onset of surgical anesthesia in about 5 minutes.
- Once the block is established, inflate the distal cuff over anesthetized skin and then deflate the proximal cuff to relieve tourniquet pain.
The hard rules
- Bupivacaine is absolutely contraindicated. If the cuff fails, a bolus of bupivacaine reaches the heart and produces refractory cardiotoxicity. Lidocaine, and in some practices prilocaine, are the accepted agents.
- Never deflate the cuff before 20 to 25 minutes have elapsed, even if the operation finishes sooner, so that local anesthetic has time to bind to tissue.
- After 20 minutes, cycle the deflation: deflate for 10 seconds, reinflate for 1 minute, and repeat. This staggers the systemic bolus.
- Cuff failure at any point produces immediate local anesthetic systemic toxicity. Lipid emulsion, airway equipment, and resuscitation drugs must be immediately available, and the total dose must be calculated and stated aloud.
Advantages and limitations
- Advantages: rapid onset, high reliability, simple, excellent for short procedures on the forearm and hand such as carpal tunnel release, ganglion excision, and closed reduction.
- Limitations: analgesia ends within minutes of cuff deflation, so there is no postoperative analgesia; tourniquet time limits the procedure to roughly 60 to 90 minutes; it is unsuitable for procedures requiring a bloodless field beyond the tourniquet; and it is less commonly used in the lower limb because the required volume approaches toxic doses.
Exam Traps
- A patient presenting for closed reduction is a full stomach, whatever the stated fasting interval.
- Bupivacaine is never used for a Bier block.
- Do not deflate the Bier cuff before 20 to 25 minutes, and cycle the deflation.
- The ankle block has five nerves, and the saphenous is the only one from the femoral nerve.
- Capnography is mandatory for procedural sedation — hypoventilation is the leading serious adverse event.
Which local anesthetic must never be used for an intravenous regional (Bier) block, and why?
A Bier block was established for a carpal tunnel release. The surgeon finishes 12 minutes after local anesthetic injection and asks for the tourniquet to be released. What is the correct response?
Which nerve blocked at the ankle does not arise from the sciatic nerve?
A 22-year-old presents 4 hours after eating for closed reduction of a displaced ankle fracture sustained 3 hours ago. Which assumption should guide management?