Treatment of Spontaneous Tumors With Algorithmically Controlled Electroporation.

OBJECTIVE: To study the safety and efficacy of algorithmically controlled electroporation (ACE) against spontaneous equine melanoma. METHODS: A custom temperature sensing coaxial electrode was paired with a high voltage pulse generation system with integrated temperature feedback controls. Computational modeling and ex vivo studies were conducted to evaluate the system's ability to achieve and maintain target temperatures. Twenty-five equine melanoma tumors were treated with a 2000V protocol consisting of a 2-5-2 waveform, 45ºC temperature set point, and integrated energized times of 0.005 s, 0.01 s, or 0.02 s (2500x, 5000x, and 10000x 2 µs pulses, respectively). Patients returned 20-50 days post treatment to determine the efficacy of the treatment. RESULTS: ACE temperature control algorithms successfully achieved and maintained target temperatures in a diverse population of spontaneous tumors with significant variation in tissue impedance. All treatments were completed successfully without and without adverse events. Complete response rates greater than 93% were achieved in all treatment groups. CONCLUSION: ACE is a safe and effective treatment for spontaneous equine melanoma. The temperature control algorithm enabled rapid delivery of electroporation treatments without prior knowledge of tissue electrical or thermal properties and could adjust to real time changes in tissue properties. SIGNIFICANCE: Real time temperature control in electroporation procedures enables treatments near critical structures where thermal damage is contraindicated. Unlike standard approaches, ACE protocols do not require extensive pretreatment planning or knowledge of tissue properties to determine an optimal energy delivery rate and they can account for changes in tissue state (e.g. perfusion) in real time to simultaneously minimize treatment time and potential for thermal damage.

Investigation of integrated time nanosecond pulse irreversible electroporation against spontaneous equine melanoma.

Introduction: Integrated time nanosecond pulse irreversible electroporation (INSPIRE) is a novel tumor ablation modality that employs high voltage, alternating polarity waveforms to induce cell death in a well-defined volume while sparing the underlying tissue. This study aimed to demonstrate the in vivo efficacy of INSPIRE against spontaneous melanoma in standing, awake horses. Methods: A custom applicator and a pulse generation system were utilized in a pilot study to treat horses presenting with spontaneous melanoma. INSPIRE treatments were administered to 32 tumors across 6 horses and an additional 13 tumors were followed to act as untreated controls. Tumors were tracked over a 43-85 day period following a single INSPIRE treatment. Pulse widths of 500ns and 2000ns with voltages between 1000 V and 2000 V were investigated to determine the effect of these variables on treatment outcomes. Results: Treatments administered at the lowest voltage (1000 V) reduced tumor volumes by 11 to 15%. Higher voltage (2000 V) treatments reduced tumor volumes by 84 to 88% and eliminated 33% and 80% of tumors when 500 ns and 2000 ns pulses were administered, respectively. Discussion: Promising results were achieved without the use of chemotherapeutics, the use of general anesthesia, or the need for surgical resection in regions which are challenging to keep sterile. This novel therapeutic approach has the potential to expand the role of pulsed electric fields in veterinary patients, especially when general anesthesia is contraindicated, and warrants future studies to demonstrate the efficacy of INSPIRE as a solid tumor treatment.

Error reporting in a large animal veterinary teaching hospital identifies medication errors occur most often in the prescribing phase of therapy.

OBJECTIVE: To identify the rate at which medication errors occurred over a 2-year period in a large animal veterinary teaching hospital and describe the types of errors that occurred. SAMPLE: 226 medication errors over 6,155 large animal visits occurred during the study period. Multiple errors may have affected the same patient. METHODS: Medication error reports from March 1, 2021, to March 31, 2023, were reviewed retrospectively and classified by species, type of drug, and month and day of the week the error occurred. Errors were categorized according to multiple previously developed systems to allow for comparison to other studies. RESULTS: 226 medication errors occurred over 6,155 patient visits in a 2-year period: 57.5% (130/226) were identified by a dedicated large animal pharmacist, and 64.2% (145/226) of errors were identified and corrected before reaching the patient. Prescription/medication order errors (58.4% [132/226]) occurred significantly more often than errors in medication preparation (21.7% [49/226]; P < .001) and administration (19.6%; P < .001). Antibiotics (48.7% [110/226]) and NSAIDs (17.7% [40/226]) were the drug classes most involved in errors. CLINICAL RELEVANCE: Most medication errors in this study occurred in the ordering/prescribing phase. This is similar to reports in human medicine, where standardized medication error reporting strategies exist. Developing and applying similar strategies in veterinary medicine may improve patient safety and outcome.