Refinement of a thermal threshold probe to prevent burns

Area of Science:

• Pain research
• Neuroscience
• Animal models

Background:

• Thermal threshold testing is crucial for pain research.
• Existing thermal probes can cause skin burning, necessitating preventative measures.
• Modifications to thermal probes are needed to improve safety and practicality.

Purpose of the Study:

• To evaluate practical modifications of thermal probes to reduce burning during threshold testing.
• To assess the efficacy and safety of novel thermal probe designs in humans and cats.

Main Methods:

• Evaluated four thermal probe modifications (Probes 1a, 1b, 2, and 3) against an unmodified probe (Probe 0) in human and feline subjects.
• Assessed probe performance based on burn area, a simple descriptive scale (SDS), and visual skin evaluation.
• Probe 3 featured reduced thermal mass and even heating, tested extensively in cats post-opioid administration.

Main Results:

• Probe 1b (water cooling) showed reduced damage compared to no cooling (P<0.05) but was cumbersome.
• Probe 3 demonstrated even heating in humans without blistering.
• In cats, Probe 3 reached high temperatures (up to 55°C) without immediate skin damage, with only mild, rapidly resolving hyperaemia observed days later.

Conclusions:

• Probe 3, designed with reduced thermal mass and even heating, is a practical and safe tool for thermal threshold testing in pain research.
• The findings suggest Probe 3 minimizes thermal injury, making it suitable for both human and animal studies.
• Further research could refine probe technology for enhanced pain threshold assessment.