RESUMEN
Studies using rodent models of neuropathic pain use sham surgery control procedures that cause deep tissue damage. Sham surgeries would thus be expected to induce potentially long-lasting postsurgical pain, but little evidence for such pain has been reported. Operant tests of voluntary behavior can reveal negative motivational and cognitive aspects of pain that may provide sensitive tools for detecting pain-related alterations. In a previously described operant mechanical conflict test involving lengthy familiarization and training, rodents freely choose to either escape from a brightly lit chamber by crossing sharp probes or refuse to cross. Here, we describe a brief (2-day) mechanical conflict protocol that exploits rats' innate exploratory response to a novel environment to detect persistently enhanced pain-avoidance behavior after sham surgeries for 2 neural injury models: thoracic spinal cord injury and chronic constriction injury of the sciatic nerve. Pitting the combined motivations to avoid the bright light and to explore the novel device against pain from crossing noxious probes disclosed a conflicting, hyperalgesia-related reluctance to repeatedly cross the probes after injury. Rats receiving standard sham surgeries demonstrated enhanced pain-like avoidance behavior compared with naive controls, and this behavior was similar to that of corresponding chronic constriction injury or spinal cord injury rats weeks or months after injury. In the case of sham surgery for spinal cord injury, video analysis of voluntary exploratory behavior directed at the probes revealed enhanced forepaw withdrawal responses. These findings have important implications for preclinical investigations into behavioral alterations and physiological mechanisms associated with postsurgical and neuropathic pain.
Asunto(s)
Reacción de Prevención/fisiología , Conducta Animal/fisiología , Traumatismos de los Nervios Periféricos/cirugía , Nervio Ciático/cirugía , Animales , Modelos Animales de Enfermedad , Masculino , Neuralgia/etiología , Traumatismos de los Nervios Periféricos/complicaciones , Ratas Sprague-Dawley , Nervio Ciático/lesiones , Médula Espinal/fisiología , Traumatismos de la Médula Espinal/complicaciones , Traumatismos de la Médula Espinal/cirugíaRESUMEN
BACKGROUND: Penicillin (PCN) accounts for most cases of antibiotic allergies. Reported PCN allergy deprives the patient from this class of antibiotics and creates hesitancy in using other beta-lactam antibiotics. The aim of this study is to report the prevalence of self-reported PCN allergy among adult patients admitted to the hospital and to examine the probable validity of these reports. METHODS: A questionnaire was conducted among 192 patients with self-reported PCN allergy who were admitted to a community hospital between July 25, 2011 and January 25, 2012. Patients admitted with an infection and treated with a beta-lactam were also followed until hospital discharge. RESULTS: The mean age of patients at the time of their self-reported allergic reaction was 20.3 years. The most common allergic symptoms reported in decreasing order of frequency were itchy rash, angioedema, and urticaria. Based on analysis of the questionnaires, 121 patients (63.0%) had probable PCN allergy, 54 (28.1%) had possible PCN allergy, and 17 (8.9%) were unlikely to have a PCN allergy. Fifty-one participants (26.6%) had self-reported subsequent exposure to PCN in their life. This subsequent exposure was well tolerated in 86.3% of the participants. Fifty participants (25.9%) had self-reported subsequent exposure to a first generation cephalosporin and it was well tolerated in 78.4% of them. CONCLUSION: Taking a detailed history from patients with self-reported PCN allergy can help to distinguish a true PCN allergy from a false positive report of allergy and hence allow clinicians to use this important class of antibiotics when truly indicated.