InfusionFox
Analgesia & Anesthesia

Oncology KL · Cornell protocol

Outpatient ketamine-lidocaine bag infusion for refractory cancer pain in dogs and cats. Adjunctive to oral analgesics (NSAIDs, gabapentinoids, opioids, amantadine, steroids), bisphosphonates, and interventional therapies. Documented benefit across osteolytic, neuropathic, visceral, and radiation-side-effect cancer pain.

2% lidocaine + 100 mg/mL ketamine in 0.9% NaCl
  • Adjunct, not monotherapy. All 114 animals in the 2025 JAVMA cohort received concomitant oral analgesics (gabapentinoids 92%, NSAIDs 70%, opioids 68%, steroids 46%, amantadine 18%). Onco KL is added on top of that regimen for refractory pain that the oral protocol can't control on its own.
  • Use 2% lidocaine WITHOUT epinephrine. Lidocaine-with-epinephrine is sold for dental and infiltration; mixing it into the bag would deliver an unintended epinephrine bolus. Read the vial.
  • Premedicate vomit-prone patients. 2 of 105 dogs in the cohort had infusion-associated vomiting; both were prevented on subsequent infusions by maropitant ± ondansetron premedication. Worth giving prophylactically in any patient with a history of nausea or motion sickness.
  • Small patients (< 15 kg), verify delivered rates. The bag-mixed protocol can underdose smaller patients who don't finish the bag during the 4–6 hr infusion. Most osteosarcoma patients are medium-to-large breeds (Goldens, Labs, Rottweilers, Saint Bernards in the 2025 cohort) where this is not an issue, but for cats and small-breed dogs with other tumor types, the result panel verifies whether delivered rates meet the published efficacy thresholds, and recommends a smaller bag if not.
Cat target lidocaine rate is 1.5 mg/kg/hr (half the dog rate) per the 2025 paper, reflecting feline lidocaine sensitivity. Ketamine target is the same for both species (0.15 mg/kg/hr).
Original Looney protocol: 500 mL for dogs ≥15 kg, 250 mL for cats and dogs <15 kg. The 2025 JAVMA paper recommends 100 mL for smaller patients to ensure target rates are met within the 4–6 hour infusion duration.
Cohort median was 5 hours. The original protocol sheet states: "Minimum 3–6 hrs Infusion necessary. Note: if patient is handling it well, it is safe to give the whole bag." For patients who finish the bag before the planned duration, see the result panel, a second bag may be needed.
Awaiting input

Enter a patient weight to see the result.

Method

How the math works

The protocol mixes ketamine and lidocaine into a single 0.9% NaCl bag, then runs the bag at the patient's maintenance fluid rate (2.5 mL/kg/hr) for 4–6 hours. Total drug added is calibrated so that the patient receives the target hourly rate while infusing the bag.

Bag preparation

$$\text{lidocaine to add (mg)} = \text{target rate} \times \text{weight} \times \text{duration}$$ $$\text{ketamine to add (mg)} = 0.15 \times \text{weight} \times \text{duration}$$ Convert to mL of stock: lidocaine ÷ 20 mg/mL, ketamine ÷ 100 mg/mL. Remove an equal total volume of saline from the bag BEFORE adding drugs, so the final bag volume is unchanged.

Delivered rates check

The same drug load delivered through a smaller bag (and therefore a higher concentration per mL) reaches the patient faster, but the infusion rate is fixed at 2.5 mL/kg/hr. So if the patient is small, the volume infused over 4–6 hours may not finish the bag, and the drug remaining in the bag at the end of the infusion is wasted. The result panel computes the delivered rate given the patient's size, the chosen bag, and the duration, and compares to the efficacy thresholds published in the 2025 paper.

Reference

Efficacy thresholds (2025 JAVMA)

The 2025 retrospective evaluation of 105 dogs and 9 cats identified three published efficacy thresholds. Patients whose delivered doses fell below these were significantly less likely to have a clinical response and were grouped as "ultralow dose" in the paper's analysis.

Threshold Equivalent Source
Lidocaine ≥ 25 µg/kg/min = 1.5 mg/kg/hr P = .0051 for clinical response
Ketamine ≥ 2 µg/kg/min = 0.12 mg/kg/hr P = .0374 for clinical response
Total ketamine ≥ 0.5 mg/kg across full infusion P = .0343 for clinical response

Formula

Step 1, calculate how many mg of each drug are needed for the target dose over the infusion duration, then convert to mL of stock to draw up.

Drug to add to bag

$$\text{mg to add} = \text{dose}_{\text{mg/kg/hr}} \times \text{weight}_{\text{kg}} \times \text{duration}_{\text{hr}}$$ $$\text{mL to draw} = \frac{\text{mg to add}}{\text{stock}_{\text{mg/mL}}}$$

Sources

  • Primary clinical evidence: Iocolano KE, Looney A, Balkman CE, Hume KR, Boesch JM, Sylvester SR. Retrospective evaluation of outpatient intravenous ketamine-lidocaine infusions for the palliation of cancer pain in dogs and cats. J Am Vet Med Assoc. 2025;263(4):499–506. doi:10.2460/javma.24.09.0595
  • Original protocol: Looney A. Cornell University College of Veterinary Medicine ketamine-lidocaine fluid infusion protocol (worksheet dated 7/5/2012); used clinically at Cornell from 2008 onward and the basis for the 2025 retrospective.
  • Component pharmacology: Plumb's Veterinary Drugs, lidocaine and ketamine monographs (current edition). See also the InfusionFox lidocaine and ketamine CRI calculators for the standard analgesic-CRI use cases.