The intraoperative phase begins when the client enters the operating room (OR) and ends with transfer to the post-anesthesia care unit (PACU). During this time the client is unable to protect themselves — anesthesia removes protective reflexes, pain perception, and the ability to report pressure, cold, or burns. The nurse's central role is client safety and advocacy.

Surgical team roles

Types of anesthesia

OR environment: restricted, semirestricted, and unrestricted zones; positive-pressure ventilation with frequent air exchanges; room temperature typically 20–24 °C (68–75 °F); doors kept closed to limit traffic and airborne contamination.

Continuous intraoperative assessment includes:

• Airway and ventilation: SpO₂, end-tidal CO₂ (capnography), breath sounds, airway pressures
• Circulation: heart rate and rhythm, blood pressure, estimated blood loss (suction canisters, weighed sponges), urine output
• Temperature — anesthesia impairs thermoregulation, and cold rooms, exposure, cold fluids, and open cavities cause heat loss
• Skin and positioning: pressure points, padding, alignment, contact with metal
• Early signs of emergencies: rising end-tidal CO₂ and jaw rigidity (malignant hyperthermia), hypotension with urticaria or wheeze (anaphylaxis), perioral numbness or seizure (local anesthetic toxicity)

A sudden fall in blood pressure during surgery is most often from bleeding or anesthetic effect — check blood loss and communicate with the surgeon and anesthesia provider at once.

Anesthesia drug safety

Malignant hyperthermia (MH) — an inherited muscle disorder in which triggers cause uncontrolled calcium release in skeletal muscle and a hypermetabolic crisis.

• Early signs: unexplained rise in ETCO₂, tachycardia, masseter (jaw) or generalized muscle rigidity, tachypnea, mixed acidosis, hyperkalemia. Fever is a late sign
• Management:
  1. Stop triggering agents; call for help; hyperventilate with 100% oxygen at high flow
  2. Dantrolene 2.5 mg/kg IV rapidly, repeated until signs resolve (usually up to 10 mg/kg, more if needed). Reconstitute with preservative-free sterile water (not saline or dextrose); the 20 mg vials need 60 mL each, so several staff are needed. Adverse effects: muscle weakness (monitor breathing and swallowing after extubation), phlebitis
  3. Active cooling if temperature is high (stop when about 38 °C (100.4 °F)); treat hyperkalemia and dysrhythmias — do not give calcium channel blockers (e.g., verapamil, diltiazem) with dantrolene (hyperkalemia and cardiovascular collapse); monitor urine output (myoglobinuria)
  4. ICU monitoring for at least 24 hours because symptoms can recur

Spinal anesthesia after-care: hypotension is treated with fluids and vasopressors; post-dural puncture headache (worse upright, better lying flat) is treated with fluids, analgesics, caffeine, or an epidural blood patch. Lying flat for hours after surgery does not prevent it.

Listed in priority order.

1. Airway, breathing, and circulation support — assist the anesthesia provider during induction and emergence; have suction ready; monitor blood loss and report hypotension immediately; prepare blood products and warmed fluids
2. Client identification and time-out — confirm client, procedure, site, allergies, antibiotic timing, and equipment before incision
3. Surgical asepsis
   • Only sterile items touch the sterile field; if sterility is in doubt, consider it contaminated
   • Sterile gowns are sterile in front from chest to the level of the sterile field and on the sleeves; tables are sterile only at table height; items below waist or table level are non-sterile
   • A wet sterile drape or wrapper is contaminated (moisture wicks microbes through — strike-through)
   • Scrubbed people pass front to front or back to back and stay within the sterile area; non-scrubbed people do not reach over the sterile field
   • Surgical hand antisepsis before gowning and gloving; change gloves when punctured
   • Keep doors closed and limit traffic and talking
4. Positioning (done with the anesthesia provider and surgeon)
   • Keep joints in neutral alignment — avoid hyperextension and extreme flexion
   • Pad bony prominences and nerve pathways; keep arms abducted less than 90° on armboards (brachial plexus); protect the ulnar nerve at the elbow and the peroneal nerve at the knee
   • Lithotomy: raise and lower both legs together, slowly (hip injury and sudden blood pressure changes)
   • Ensure breathing and circulation are not restricted; skin must not touch metal
   • Move anesthetized clients slowly and as a unit with enough staff; after spinal anesthesia, move the legs together and change position slowly because blocked sympathetic tone can cause sudden hypotension
5. Electrosurgical safety
   • Place the dispersive (return) electrode over a large, well-perfused muscle mass (thigh, buttock) on clean, dry, hairless skin, with full, even contact and no air gaps; avoid bony prominences, scars, and metal implants
   • Do not place the pad over fluid-soaked linen; keep the active electrode in a holster when not in use
6. Fire prevention — the triad is oxygen, an ignition source, and fuel. Let alcohol-based skin prep dry completely before draping; for head, neck, and upper chest surgery under sedation, use the lowest oxygen concentration that keeps SpO₂ acceptable (commonly FiO₂ 30% or less)
7. Surgical counts — count sponges, sharps, and instruments before the procedure, before closing a cavity, at skin closure, and at staff change. The main purpose is to prevent retained surgical items. For an incorrect count, notify the surgeon, search, and obtain imaging per policy
8. Normothermia — cover exposed areas, forced-air warming, warmed IV and irrigation fluids; aim to keep core temperature at 36 °C (96.8 °F) or above
9. Specimens — label in the room with client identifiers, specimen source and site (including side), type, date and time, and fixative; send with a requisition and track chain of custody
10. Documentation — positioning, skin condition, devices, counts, specimens, implants, and personnel; give a structured handoff to PACU

Teaching during this phase is directed to the client before induction and to the family:

• Explain what the client will experience in the OR (monitors, cool room, warm blankets, oxygen mask) and that staff will stay with them
• Clients receiving regional anesthesia or sedation may be awake: explain sensations of pressure without pain, and ask them to report pain, dizziness, or nausea
• Keep the family informed of progress through the designated contact process

• Circulating nurse = non-sterile advocate: counts, documentation, supplies, specimens; scrub = sterile field and instruments
• Wet sterile field = contaminated; doubt = contaminated; sterile only at table and waist level and above
• Counts at start, before cavity closure, at skin closure, and at staff change — to prevent retained items
• Dispersive pad: large muscle mass, dry, hairless, full contact; avoid bony areas and metal implants
• Joints in neutral position; arms abducted under 90°; lithotomy legs moved together slowly
• MH: earliest sign rising ETCO₂, jaw rigidity; fever is late → dantrolene 2.5 mg/kg
• Succinylcholine and inhaled agents trigger MH; succinylcholine also causes hyperkalemia
• Intraoperative hypotension → check blood loss first
• Prevent hypothermia: cover, warm air, warm fluids; OR temperature about 20–24 °C
• Spinal anesthesia → hypotension; lying flat does not prevent post-dural puncture headache
• Specimen label: client identifiers and exact anatomic site