Block, Neuraxial, Pain, PONV, and Delirium Cases
Key Takeaways
- Regional and neuraxial cases require knowing expected block effects, dangerous spread, local anesthetic systemic toxicity, and procedure-specific monitoring.
- PACU pain control balances analgesia against respiratory rate, sedation, opioid tolerance, regional technique, and non-opioid adjuncts.
- PONV risk rises with volatile agents, opioids, female sex, nonsmoking status, prior PONV or motion sickness, and certain laparoscopic, gynecologic, ENT, and eye surgeries (the Apfel score uses four of these).
- Emergence delirium and agitation demand a physiologic search before the behavior is labeled anxiety, noncompliance, or dementia.
- Group misses by technique-specific complication: peripheral block, neuraxial block, pain safety, PONV, or cognitive recovery.
Technique-specific thinking
A regional block is not just a pain plan; it reshapes assessment, safety, and surveillance. A dense lower-extremity block creates fall risk. An interscalene block commonly causes ipsilateral phrenic nerve (diaphragm) palsy, so dyspnea may be expected — but worsening respiratory distress is not. A neuraxial block (spinal or epidural) can cause hypotension, bradycardia, urinary retention, high-spinal symptoms, or delayed motor recovery. Local anesthetic can trigger local anesthetic systemic toxicity (LAST) when neurologic symptoms and cardiovascular instability appear together.
When a stem names a block, ask three questions: what should be numb or weak, what should not be affected, and which complication matches the timing? Expected numbness in the surgical limb is worlds apart from tinnitus, metallic taste, circumoral numbness, agitation, seizures, or sudden dysrhythmia after local anesthetic dosing — that progression is the LAST sequence, and treatment is 20 percent lipid emulsion plus stopping the anesthetic and calling for help.
Case pattern: comfort with safety limits
A patient on chronic opioid therapy arrives after shoulder repair with an interscalene catheter. Pain is 8/10, RR 10, SpO2 93 percent on oxygen, sleepy but arousable. Neither withholding all analgesia nor pushing repeated opioid boluses without reassessment is correct. CPAN reasoning supports a multimodal plan: verify catheter function and the sensory distribution, use ordered non-opioid adjuncts (acetaminophen, an NSAID if not contraindicated, dexamethasone), titrate opioids in small increments, monitor ventilation and sedation between doses, and consult anesthesia or the acute pain service when pain stays severe despite a working block.
PONV and delirium are assessment problems
Postoperative nausea and vomiting (PONV) delays recovery, raises aspiration risk, stresses fresh wounds, and elevates intraocular or intracranial pressure in vulnerable patients. The Apfel score counts four risk factors — female sex, nonsmoker, history of PONV or motion sickness, and expected postoperative opioids — predicting roughly 10, 20, 40, 60, and 80 percent risk for 0 to 4 factors. Treat with ordered antiemetics from different classes (a 5-HT3 antagonist such as ondansetron, dexamethasone, a dopamine antagonist), hydration assessment, oxygenation, pain control, and trigger reduction.
Agitation after anesthesia may be pain, hypoxia, hypercarbia, bladder distention, hypoglycemia, stroke, medication effect, alcohol withdrawal, pediatric emergence delirium, or postoperative delirium in an older adult. Protect the patient, secure lines and drains, reorient calmly, invite a familiar caregiver when appropriate, and escalate abnormal physiology. Restraints and sedatives are not first-line until correctable causes are ruled out.
Integrated cue table
| Cue | Concern | Priority action |
|---|---|---|
| Tinnitus, metallic taste, then seizure | Local anesthetic systemic toxicity | Stop local anesthetic, call help, prepare 20% lipid emulsion |
| Numb hands, dyspnea, bradycardia, hypotension after spinal | High neuraxial block | Airway and circulation support, notify anesthesia |
| Severe pain plus RR 8 | Analgesia limited by ventilation | Support breathing, reassess sedation, use multimodal options |
| Repeated vomiting after eye surgery | Pressure and aspiration risk | Antiemetic, protect airway, notify if persistent |
| Pulling lines, new confusion, SpO2 88% | Delirium driven by physiology | Safety, oxygenation, pain, glucose, bladder, neuro assessment |
Remediation grid
| Miss type | Review target | Practice task |
|---|---|---|
| Block complication missed | Anatomy and spread | One expected-versus-dangerous card per block |
| Gave opioid despite hypoventilation | Pain-safety balance | Pair every pain score with RR and sedation score |
| Treated PONV as minor | Complication awareness | Link vomiting to wound, airway, eye, and neuro risk |
| Restrained delirious patient first | Cognitive recovery | Drill physiologic causes before behavior labels |
| Ignored neuraxial level | Technique context | Review high-spinal and hypotension cue clusters |
A patient with a continuous peripheral nerve block reports ringing in the ears, a metallic taste, and circumoral numbness, then has a brief seizure. What is the priority nursing response?
A patient recovering from spinal anesthesia develops numbness in the hands, difficulty speaking, dyspnea, bradycardia, and hypotension. Which action is most appropriate?
An 82-year-old is pulling at the IV and trying to climb over the side rail after hip surgery. SpO2 is 88%, a bladder scan shows 650 mL, and pain is 8/10. What is the best interpretation?
Expected versus dangerous neuraxial findings
After a spinal or epidural the nurse must separate normal recovery from a complication. Expected findings include a bilateral sensory and motor level that gradually recedes from the feet upward, mild hypotension that responds to fluids, and temporary urinary retention. Dangerous findings include an ascending block reaching the chest or hands, dyspnea, bradycardia, profound hypotension, slurred speech, or no motor recovery long after the expected window, which can signal a high block or, rarely, an epidural hematoma compressing the cord.
New or worsening back pain with progressive weakness after neuraxial anesthesia is a surgical emergency that the nurse escalates at once.
For urinary retention, a bladder scan over roughly 400 to 500 mL with an inability to void warrants catheterization per order; an overdistended bladder is also a common reversible cause of agitation in the recovering patient.
Pain-safety titration in practice
Titrate opioids to function and safety, not to a target pain number alone. Reassess respiratory rate, sedation score, and saturation before and after each dose, and hold further opioid when the patient is sedated or the respiratory rate is below about 8 to 10. Lean on the multimodal plan: acetaminophen, an NSAID when not contraindicated, dexamethasone, regional catheters, ice, and positioning all reduce opioid demand. For a patient with a working regional block reporting severe pain, verify catheter integrity and the sensory distribution first, because a displaced or disconnected catheter, not undertreatment, is often the cause.