anesthesia-protocols

# Anesthesia Protocols ## Overview Species-specific anesthesia protocols including premedication, induction, maintenance, and monitoring. This skill covers the practical protocol selection — for safety monitoring, emergency management, and breed-specific risk assessment, see the companion skill `anesthesia-safety`. ## When to Use - User needs an anesthesia protocol for a specific species and procedure - User asks about drug selection for premedication, induction, or maintenance - User asks about species-specific anesthetic considerations - Keywords: anesthesia, sedation, premedication, induction, intubation, isoflurane, sevoflurane, propofol, alfaxalone, dexmedetomidine, ASA, monitoring ## Standard Canine Protocol | Phase | Drug Options | Dose Range | Notes | | --- | --- | --- | --- | | Premedication | Dexmedetomidine + Hydromorphone | 5-20 mcg/kg IM + 0.1 mg/kg IM | Adjust for ASA status; reduce for debilitated patients | | Premedication (alt) | Acepromazine + Butorphanol | 0.01-0.05 mg/kg IM + 0.2-0.4 mg/kg IM | Avoid ace in Boxers, MDR1 breeds | | Induction | Propofol | 2-6 mg/kg IV to effect | Titrate slowly; apnea risk at higher doses | | Induction (alt) | Alfaxalone | 1-3 mg/kg IV to effect | Good for cardiovascular compromise | | Maintenance | Isoflurane or Sevoflurane | MAC: iso 1.3%, sevo 2.3% | Sevoflurane: faster induction/recovery, more expensive | | Analgesia | Fentanyl CRI | 2-5 mcg/kg/hr IV | Reduces MAC by 30-50%; manage bradycardia | ## Standard Feline Protocol | Phase | Drug Options | Dose Range | Notes | | --- | --- | --- | --- | | Premedication | Dexmedetomidine + Buprenorphine | 10-40 mcg/kg IM + 0.02 mg/kg IM | Can combine in same syringe (IM kitty magic) | | Premedication (alt) | Alfaxalone + Butorphanol | 2 mg/kg IM + 0.3 mg/kg IM | Good for fractious cats | | Induction | Propofol | 2-6 mg/kg IV to effect | Cats: Heinz body anemia with repeat dosing (avoid CRI) | | Induction (alt) | Alfaxalone | 1-3 mg/kg IV to effect | Preferred for cats needing repeated anesthesia | | Maintenance | Isoflurane or Sevoflurane | MAC: iso 1.6%, sevo 2.6% | Higher MAC than dogs | ## Equine Protocol (Standing Sedation) | Drug | Dose | Route | Duration | | --- | --- | --- | --- | | Xylazine | 0.5-1.1 mg/kg | IV | 20-30 min | | Detomidine | 10-40 mcg/kg | IV | 30-90 min | | Butorphanol | 0.01-0.04 mg/kg | IV | Combine with alpha-2 for neuroleptanalgesia | ## Equine Protocol (General Anesthesia) | Phase | Drug | Dose | Notes | | --- | --- | --- | --- | | Premedication | Xylazine or Detomidine | As above | Wait for full sedation before induction | | Induction | Ketamine + Diazepam | 2.2 mg/kg + 0.05 mg/kg IV | Administer rapidly as bolus | | Maintenance | Isoflurane (Triple Drip alternative) | MAC 1.3% (or ketamine/xylazine/GGE CRI) | Equine anesthesia carries ~1% mortality risk (10x higher than small animal) | | Recovery | Quiet, padded recovery stall | Assisted vs. unassisted | Most critical phase; myopathy and fracture risk | ## Breed-Specific Safety Alerts - **Boxers:** Acepromazine sensitivity — risk of profound, prolonged hypotension. Use alternative sedation (dexmedetomidine, butorphanol). - **Sighthounds (Greyhounds, Whippets, etc.):** Prolonged recovery from thiopental and propofol due to low body fat. Dose-reduce propofol. Alfaxalone may be preferred. - **MDR1-Mutant Breeds (Collies, Aussies, Shelties, etc.):** Exercise caution with acepromazine, butorphanol, and other P-glycoprotein substrates. Dose-reduce by 25-50% or substitute. Test MDR1 status when possible. - **Brachycephalics (Bulldogs, Pugs, Persians):** High risk for upper-airway obstruction. Pre-oxygenate, have multiple endotracheal tube sizes ready, avoid heavy sedation, and delay extubation until strong swallow reflex. - **Giant breeds (Great Dane, Mastiff, Irish Wolfhound):** Higher sensitivity to alpha-2 agonists. Increased bloat/GDV risk perioperatively. Position carefully to prevent myopathy/neuropathy. - **Pediatric (<12 weeks):** Immature hepatic metabolism, limited glycogen reserves (hypoglycemia risk), higher body surface area (hypothermia risk). Reduce drug doses, minimize fasting, maintain body temperature aggressively. - **Geriatric:** Reduced hepatic/renal clearance, cardiac reserve. Pre-anesthetic bloodwork mandatory. Reduce doses 25-50%. ## Key Species Differences | Parameter | Dog | Cat | Horse | | --- | --- | --- | --- | | Mortality risk | ~0.1% | ~0.2% | ~1% | | Propofol CRI | Acceptable | Avoid (Heinz bodies) | Not used | | Alpha-2 reversal | Atipamezole | Atipamezole | Atipamezole (caution) | | Intubation | Straightforward | Laryngospasm common; use lidocaine spray | Blind nasal or oral | | Common emergency | Hypotension | Hypothermia, bradycardia | Myopathy, recovery fractures | ## Workflow 1. **Confirm species, breed, age, weight, and ASA status** (MANDATORY). 2. **Review pre-anesthetic bloodwork** (CBC, chemistry, coagulation if indicated). 3. **Select premedication** based on species, temperament, and procedure. Account for breed-specific contraindications. 4. **Select induction agent** and calculate dose. Titrate to effect. 5. **Intubate and maintain** on inhalant or injectable protocol. Monitor continuously (SpO2, ETCO2, ECG, BP, temperature). 6. **Manage analgesia** throughout: multimodal approach (opioid + NSAID + local block where possible). 7. **Recovery monitoring** until patient is extubated, normothermic, and ambulatory. ## Limitations - Anesthetic protocols must be individualized based on patient assessment; no single protocol suits all cases. - Drug availability varies by country and institution. Not all agents are licensed in all jurisdictions. - Equine anesthesia carries inherently higher risk than small animal; specialist involvement is recommended for complex cases. - Dosing information is for reference only; always verify against current formulary (Plumb's) and patient-specific factors. - This skill covers protocol selection. For safety monitoring, emergency management, and breed risk details, see `anesthesia-safety`.