Mechanical nociceptive thresholds using four probe configurations in horses

PK/PD modeling of flunixin meglumine in a kaolin‐induced inflammation model in piglets

“…This observation is also in agreement with the previous study using similar methodology to assess ketoprofen analgesic properties (Fosse, Toutain et al, 2011). The use of algometer tips of various shapes and sizes has been shown F I G U R E 5 Example of the predicted mechanical nociceptive thresholds (MNT) at the left metacarpus and flunixin plasma concentration (Cp) obtained by PK/PD modeling from algometry testing with a 1-cm 2 tip in one piglet after kaolininduced inflammation and intravenous administration of flunixin meglumine at 4.4 mg/kg (group HIGH) T A B L E 2 Pharmacodynamic parameters describing the effect of intravenous flunixin meglumine at two different doses of 2.2 (group MEDIUM) and 4.4 (group HIGH) mg/kg as well as both groups combined together, on the mechanical nociceptive thresholds tested with the 1-cm 2 tip F I G U R E 6 Relationship between flunixin dose administered intravenously and its effect to inhibit kaolin-induced hyperalgesia as recorded by quantitative algometry with a 1-cm 2 tip in 10-days-old piglets to evoke different thresholds and response variability (Taylor et al, 2016;Treede, Rolke, Andrews, & Magerl, 2002). Larger probes may also activate deeper nerve endings (Treede et al, 2002).…”

“…This observation is also in agreement with the previous study using similar methodology to assess ketoprofen analgesic properties (Fosse, Toutain et al., ). The use of algometer tips of various shapes and sizes has been shown to evoke different thresholds and response variability (Taylor et al., ; Treede, Rolke, Andrews, & Magerl, ). Larger probes may also activate deeper nerve endings (Treede et al., ).…”

“…But it remains unclear how the results obtained from tips of different sizes can be interpreted. The lower MNTs evoked by the smaller algometer tip may help to improve sensitivity when comparing the pharmacodynamic effect of different treatments (Taylor et al., ). In the present study, the differences between the groups were more significant with the larger 1 cm 2 tip.…”

Factors affecting mechanical nociceptive thresholds in healthy sows

“…Data collected from different studies should be easily compared, but variation in methodology makes comparison difficult. Probe tip profile and diameter clearly affect MNT (Greenspan & McGillis 1991;Fosse et al 2011b;Taylor et al 2016). The nociceptor is activated by pressure (Le Bars et al 2001), and as pressure = force/area, larger-diameter probe tips will require higher forces to produce the same pressure.…”

Pain

“…Pressure algometry has been shown to provide reliable and repeated objective assessment of mechanical nociception thresholds in studies investigating thoracic limb pain associated with induced synovitis or osteoarthritis, muscle pain, mechanical nociceptive thresholds of the pastern region and the axial skeleton, and to measure the effect of sedative drugs in the provision of analgesia 7,36 This technique is used increasingly in research studies investigating pain and has been suggested for use in the objective clinical evaluation of axial skeleton pain. 4,37 Pressure-calibrated hoof testers have been used to quantify pain in laminitic horses.…”