PACU Emergencies: MH, LAST, Aspiration, and Deterioration

Malignant Hyperthermia Pattern

Malignant hyperthermia (MH) is a hypermetabolic crisis associated with susceptible patients exposed to triggering agents such as volatile anesthetics or succinylcholine. Hyperthermia may be late, so do not wait for a high temperature. Earlier clues include unexplained rising end-tidal carbon dioxide, tachycardia, generalized or masseter rigidity, acidosis, hyperkalemia, dysrhythmias, cola-colored urine, and rapid temperature rise.

The first response is crisis activation. Call for help, notify anesthesia and the surgeon, obtain the MH cart, deliver high-flow 100% oxygen and hyperventilation as directed, prepare dantrolene, initiate active cooling when indicated, and support labs and monitoring for acidosis, potassium, renal injury, and coagulation problems. Stop cooling when directed to avoid overshoot hypothermia.

LAST Pattern

Local anesthetic systemic toxicity (LAST) may follow regional blocks, wound infiltration, or local anesthetic infusions. Early neurologic findings can include circumoral numbness, metallic taste, tinnitus, dizziness, agitation, confusion, tremor, or seizure. Cardiovascular toxicity may include hypotension, conduction delay, ventricular dysrhythmias, or arrest.

First actions are to stop the local anesthetic source if present, call for anesthesia help, protect airway and oxygenation, treat seizures per orders, and prepare 20% lipid emulsion according to the facility's LAST protocol. Avoid delay because neurologic symptoms can progress quickly to cardiovascular collapse.

Aspiration and Airway Contamination

Aspiration risk increases with depressed airway reflexes, vomiting, ileus, pregnancy, obesity, emergency surgery, opioids, and delayed gastric emptying. If aspiration is suspected, turn or position the patient to protect the airway when safe, suction the mouth and pharynx, apply oxygen, assess lung sounds and SpO2, and prepare for bronchoscopy, intubation, chest imaging, or higher-level monitoring if ordered. Persistent wheeze, crackles, fever, hypoxemia, or respiratory distress requires escalation.

Deterioration Without a Label

Not every emergency announces itself. A patient may first show restlessness, new confusion, increasing oxygen need, tachycardia, narrowing pulse pressure, decreasing urine output, or a rhythm change. Treat deterioration as real until proven otherwise. Reassess ABCs, verify monitors and lines, inspect wounds and drains, review recent medications, and call for help early.

Protocol Thinking

For rare crises, the correct answer is rarely solitary heroics. Use the emergency cart or checklist, assign tasks, request additional staff, and follow facility protocol for medications, labs, cooling, lipid therapy, documentation, and transfer. The nurse's value is early recognition plus organized escalation while basic oxygenation, ventilation, and perfusion support continue.

Communication Under Pressure

Use a short report: procedure, anesthetic and block exposure, current ABC status, vital-sign trend, rhythm, temperature, neurologic status, output or bleeding, suspected complication, and interventions already started. The exam favors answers that mobilize the team while the nurse continues immediate stabilization at the bedside.