Anesthesia Types, Drugs, and Post-Anesthesia Care

Goals of Anesthesia

  • Prevent pain (analgesia)
  • Produce adequate muscle relaxation
  • Calm fears & ease anxiety
  • Induce amnesia (forgetfulness)

Broad Categories of Anesthesia

  • General Anesthesia (GA)

    • Induction usually starts with an IV agent → patient unconscious long enough for airway device placement.
    • Patient is unconscious, has complete loss of sensation, cannot maintain own airway.
    • Common intra-op maintenance: inhalation gases.
    • Adverse effects of inhalation agents:
    • Respiratory depression
    • Delirium during induction/recovery
    • Nausea & vomiting (N/V)
    • Hepatic toxicity → monitor liver (ALT, AST)
    • Nursing priorities/interventions (PACU & floor):
    • Ensure & maintain patent airway
    • Protect & orient client while emerging
    • Monitor VS continuously (watch for trends)
    • Lab surveillance for liver injury (ALT/AST)
    • Aspiration prevention: elevate HOB if tolerated or turn lateral

  • Local Anesthesia (LA)

    • Injection or topical application to a small, specific area (e.g., single tooth, minor skin excision, ear cartilage issue).
    • Patient fully awake, airway intact.
    • Provider can be MD, PA, NP, etc. (does not require anesthesiologist/CRNA).

  • Regional Anesthesia (RA)

    • Blocks peripheral nerves or spinal cord → loss of sensation to a region without loss of consciousness.
    • Patient remains awake, can protect airway.
    • Sub-types & details:
    • Spinal: inject into CSF in subarachnoid space → autonomic, sensory & motor block below injection level.
      • Uses: C-sections, lower-body ortho, emergent cases when NPO status unknown.
      • Adverse: hypotension, post-spinal headache.
    • Epidural: inject into thoracic/lumbar epidural space; blocks sensory pathways, motor may remain intact.
      • Uses: labor analgesia, abdominal & lower-extremity surgery.
      • Adverse: block may “climb” → respiratory depression, hypotension, nerve pain.
    • Caudal: inject into caudal epidural space near tailbone.
      • Blocks lower abdomen, pelvis, perineum, legs.
      • Pediatric hernia repair, perineal or chronic low-back pain in adults.
      • Complications: failed/incomplete block, urinary retention, back pain.

  • Moderate / Conscious Sedation (MCS)

    • IV meds produce depressed LOC but pt can follow commands & maintain airway.
    • Typical sites: ED shoulder reduction, bedside procedures, dialysis shunt revision.
    • May be administered by an RN with ACLS/PALS training; one nurse medicates, another monitors.
    • Common drug: midazolam (Versed).
    • Adverse effects: respiratory depression, apnea, bradycardia.
    • Nursing interventions:
    • Never leave patient unattended
    • Continuous airway & SPO₂ monitoring, VS q15–30 min
    • Be ready with reversal agent (flumazenil)

Who Can Administer What?

  • GA & RA → anesthesiologist or CRNA only.
  • LA → any qualified provider (MD, PA, NP, dentist, etc.).
  • MCS → specially trained RN (ACLS/PALS) or anesthesia personnel.

Key Anesthetic Drugs

  • Propofol (Diprivan)

    • Milky white IV emulsion, rapid onset & awakening → ideal for short outpatient cases, colonoscopy, vent sedation.
    • Safe in liver/kidney disease; used for induction or maintenance.
    • Adverse: bradycardia, ↓BP, transient phlebitis, injection pain, hiccups.
    • Nursing:
    • Continuous VS & airway monitoring
    • Inspect IV lines post-op; residual propofol in connector can cause inadvertent bolus → sudden sedation.

  • Morphine Sulfate (opioid)

    • Provides analgesia during & after surgery.
    • Adverse: respiratory depression, vomiting, ↓HR.
    • Nursing:
    • Focused respiratory assessment, maintain airway
    • Know reversal agent: naloxone (Narcan)

  • Midazolam (Versed) – benzodiazepine of choice for MCS

    • Effects: anxiolysis, amnesia, induction & maintenance of light anesthesia.
    • Adverse: respiratory depression, ↓BP, ↑HR, prolonged sedation/confusion.
    • Nursing:
    • Protect airway, monitor respirations & SPO₂
    • Reversal: flumazenil (Romazicon)

Post-Anesthesia Care Unit (PACU)

  • Purpose: allow safe emergence from anesthesia while controlling pain & preventing complications.
  • Key tasks on arrival:
    • Receive hand-off (often from anesthesiologist/CRNA)
    • Apply cardiac monitor, pulse ox, BP cuff immediately
    • VS frequency: q15\text{ min} (follow institutional protocol)
    • Concerning BP change: drop of \ge 15–20\,\text{mmHg} (systolic or diastolic) → notify provider.
    • Always analyze TREND rather than single value (need ≥3–4 readings).

Rapid Head-to-Toe Assessment

  • Airway: patent? artificial airway present? tongue obstruction?
  • Breathing: lung sounds, SPO₂, RR.
  • Circulation:
    • Signs of internal/external bleeding (hematoma, tachycardia, hypotension, restlessness)
    • Skin color/temp, cap refill, distal pulses (esp. vascular access or limb surgery)
  • Neurologic: LOC, motor strength, sensation, stimulation needed to arouse.
  • I&O / GI / GU:
    • Bowel sounds, Foley output, drains (JP, chest tube)
  • Wounds & dressings:
    • Reinforce heavily soaked dressings; do NOT remove in PACU
    • Character & volume of drainage
  • Devices: IV integrity, line security (no residual propofol!), oxygen delivery, chest tubes, etc.
  • Positioning:
    • Once awake → raise HOB to improve ventilation
    • If nausea/vomiting risk → lateral position to prevent aspiration

Aldrete Scoring System (0–2 points each)

  • Activity (movement in extremities)
  • Respiration (ability to breathe & cough)
  • Circulation (BP within \pm20\% of pre-op)
  • Consciousness (fully awake to unresponsive)
  • O₂ Saturation (>92\% on RA = 2)

Total possible =10; discharge requires \ge9.

PACU Discharge Criteria

  • Aldrete score \ge9–10
  • Stable VS
  • No active bleeding
  • Gag, cough, swallow reflexes intact
  • Minimal or absent N/V
  • Urine output \ge 30\,\text{mL/hr}
  • Wound drainage minimal-to-moderate

Additional notes

  • ICU patients may bypass PACU & recover in ICU directly.

Ethical, Practical, & Exam Connections

  • ABCs always trump—all anesthesia questions circle back to airway maintenance.
  • Know reversal agents cold for exam & practice: Naloxone (opioids), Flumazenil (benzodiazepines).
  • Trend analysis vs. single VS reading—a recurring NCLEX concept.
  • Awareness of who is legally allowed to administer each anesthesia type speaks to scope-of-practice questions.
  • Propofol line flushing anecdote underscores medication safety & hand-off communication.
  • Urine output ≥30\,\text{mL/hr} → core renal perfusion benchmark in multiple systems questions.

Quick Study Flash Points

  • GA → unconscious + airway device; watch hepatic labs.
  • Spinal vs Epidural: both regional, but spinal in CSF (↑headache risk); epidural in epidural space (↑respiratory depression if level rises).
  • Caudal = lowest epidural; common in pediatrics.
  • MCS = pt follows commands; RN with ACLS can give.
  • Propofol = "milk of amnesia"; rapid on/off.
  • Morphine → naloxone; Versed → flumazenil.
  • Aldrete ≥9 + UO ≥30\,\text{mL/hr} required to leave PACU.