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Purpose: The temporal and spatial formation of the temperature field and its changes during/upon water-filtered infrared-A (wIRA)-irradiation in porcine skin and subcutis were investigated in vivo in order to get a detailed physical basis for thermotherapy of superficial tumors and infections caused by thermosensitive microbial pathogens (e.g., Mycobacterium ulcerans causing Buruli ulcer). Methods: Local wIRA-hyperthermia was performed in 11 anesthetized piglets using 85.0 mW cm-2, 103.2 mW cm-2 and 126.5 mW cm-2, respectively. Invasive temperature measurements were carried out simultaneously in 1-min intervals using eight fiber-optical probes at different tissue depths between 2 and 20 mm, and by an IR thermometer at the skin surface. Results: Tissue temperature distribution depended on incident irradiance, exposure time, tissue depths and individual 'physiologies' of the animals. Temperature maxima were found at depths between 4 and 7 mm, exceeding skin surface temperatures by about 1-2 K. Tissue temperatures above 37 °C, necessary to eradicate M. ulcerans at depths <20 mm, were reached reliably. Conclusions: wIRA-hyperthermia may be considered as a novel therapeutic option for treatment of local skin infections caused by thermosensitive pathogens (e.g., in Buruli ulcer). To ensure temperatures required for heat treatment of superficial tumors deeper than 4 mm, the incident irradiance needed can be controlled either by (a) invasive temperature measurements or (b) control of skin surface temperature and considering possible temperature increases up to 1-2 K in underlying tissue.

This blinded prospective study investigated analgesic effects of intramuscular (IM) butorphanol, meloxicam or intratesticular (IT) lidocaine for castration of 7-14 days old piglets under isoflurane anaesthesia. 66 piglets were randomly injected with: meloxicam IM (0.4 mg/kg; group M), butorphanol IM (0.2 mg/kg; group B), or both (group BM) 20 minutes prior to castration, or lidocaine IT (4 mg/kg (group ML4) or 8 mg/kg (group ML8)) together with meloxicam IM (0.4 mg/kg) under anaesthesia with 1.8% end-tidal isoflurane. Heart rate, respiratory rate, mean arterial blood pressure and end-tidal carbon dioxide were recorded. Anaesthesia quality was scored and postoperative behaviour assessed. As butorphanol caused unacceptable side effects, its use was stopped. Group M showed worse anaesthesia quality than ML4 and ML8 (higher incidence of movements: 11/17, 3/18 and 4/17, respectively). There were no significant differences between groups regarding parameters measured during castration. Postoperative behaviour did not differ between groups. For castration of 7-14 days old piglets under isoflurane anaesthesia, IT lidocaine provides an additional side effect free analgesia.