F. C. Camargo

Trimetoquinol: bronchodilator effects in horses with heaves following aerosolised and oral administration

REASON FOR PERFORMING STUDY The bronchodilator effects of trimetoquinol (TMQ) have been studied when administered i.v. or intratracheally, but not in an aerosolised form. OBJECTIVES To define the relationship between the therapeutic and adverse responses (therapeutic index) of TMQ when administered as an aerosol or by the oral route. METHODS Increasing doses of TMQ were administered to horses with heaves as an aerosol and by the oral route. Dose ranged 100-1000 microg/horse for aerosolised TMQ and from 6-60 microg/kg bwt for the oral route. Airway and cardiac effects were assessed by measurement of maximal change in pleural pressure (deltaPplmax) and heart rate (HR), respectively. Side effects of sweating, agitation and muscle trembling were scored subjectively. Duration of action of aerosolised (1000 pg/horse) and oral (6-60 microg/kg bwt) TMQ was evaluated over 6 h. RESULTS Aerosol administration of TMQ caused dose-dependent bronchodilation but did not change HR or cause other observable side effects. When 1000 microg/horse was administered via aerosol, TMQ produced a 2-phase bronchodilation; an immediate effect lasting up to 30 min and a second phase between 2 and 4 h. Oral TMQ was therapeutically ineffective. CONCLUSION Aerosol administration of TMQ is a safe and effective method of producing bronchodilation in horses.

Plasma and urinary concentrations of trimetoquinol by LC‐MS‐MS following intravenous and intra‐tracheal administration to horses with heaves

Trimetoquinol (TMQ) is a very potent and fast acting bronchodilator in horses with heaves. This study assessed the plasma and urinary concentrations of TMQ in horses with heaves following administration via the intravenous (IV, 0.2 microg/kg) and intra-tracheal (IT, 2 microg/kg) routes. TMQ was administered to six horses affected with heaves (RAO - Recurrent Airway Obstruction, used interchangeably) by the above routes and plasma and urine samples collected and stored at -20 degrees C until analyzed. Solid Phase Extraction (SPE) of TMQ was followed by highly sensitive ESI(+)-LC-MS-MS (ElectroSpray Ionization, positive mode - Liquid Chromatography - Mass Spectrometry - Mass Spectrometry); with a Limit of Detection (LOD) estimated at 1 pg/mL. Following IV administration, TMQ plasma levels peaked at 1 min at 707 pg/mL, and at 9 min at 306 pg/mL following IT administration. Our results show that TMQ plasma concentrations decline rapidly following IV administration, which is consistent with the fast onset and short duration of TMQ effect that was observed in our previous studies. On the other hand, IT administration showed a very unique plasma concentration pattern. From a regulatory standpoint, the current available TMQ ELISA kit was also used in an attempt to detect TMQ from the plasma and urine samples. We report that the ELISA kit was unable to detect TMQ from any of the samples generated in these studies.

Horse-related injuries: Causes, preventability, and where educational efforts should be focused

Abstract A high percentage of equestrians will experience accidents, with different degrees of severity, throughout their riding careers. Horse-related injuries have the highest likelihood of requiring hospitalization based on individuals visiting US emergency departments. Studies have shown that the majority of injured riders said they could have prevented the accident and the injury was due to rider/handler error. Therefore, equestrians reported their injuries, and a panel of experts analyzed these reports to better understand the causes, how to prevent, and where to invest educational resources to generate a reduction in horse-related accidents. The majority of riders reported intermediate riding skills, most accidents occurred in the arena, and most were preventable. The most severe accidents occurred when the weather played a major role, as opposed to the least severe accidents when riders were in the horse’s space. Avoidable accidents included when tack broke, as opposed to unavoidable accidents such as horses slipped or fell. Educational Impact Index was calculated with combined results of the cause of injury, avoidability, and severity. Other humans, horse spooked, and tack/equipment problems were the main causes of accidents with the highest educational impact index, and authors believe that educational efforts should be focused on these categories.

Irritability and aggression in persistent youth concussions

Objective To assess whether irritability and aggression are viable indicators of persistent post-concussive symptoms in adolescents. Design Group differences between those diagnosed with concussions were analysed using ANOVAs (p < 0.05). Setting Outpatient clinic. Participants 46 concussed adolescents age 12–17 with persisting concussion symptoms were assessed. Athletes were split into two groups: those endorsing irritability/aggression (AGG, n=24) and a control group of those denying irritability/aggression (CON, n=22). Those with baseline psychiatric history and/or special education were excluded. Assessment of risk factors Post-concussive symptom variable relationships were assessed. Outcome measures group differences were analysed using ANOVAs. Results Adolescents endorsing irritability/aggression reported more fatigue (p=0.002), disordered sleep (p=0.001), anxiety (p=0.028), depression (p=0.003), and mood lability (p<0.001) during clinical assessment. Adolescents reporting more irritability also had elevated scores on related psychometric scales, including the Beck Youth Inventory-II Anxiety [t(41)=−2.916, p = 0.006], Depression [t(41)=−3.551, p = 0.001], and Anger Scales [t(41)=−2.958, p=0.005]. Conclusions Results indicate that adolescents with self-reported irritability and aggression post-concussion were more likely to display more affective symptoms than those who did not endorse irritability and aggression following concussions. They were also more likely to complain of fatigue and disordered sleep. These findings suggest that change in level of irritability/aggression could potentially serve as an identifiable indicator for parents and coaches to recognise when an adolescent is not recovering well post-concussion. Competing interests None.

Clinical affect and sensory correlates in adolescent sports concussions

Objective Identifying risk factors is important in adolescent sports concussions. This study aimed to explore the relationship between affective symptoms and physical symptoms in youth concussions. Design Athletes were split into two groups: self-reported emotional symptoms (irritability/aggression, anxiety, depression, apathy, and/or labile mood; EMO, n=22) and a control group without emotional symptoms (CON, n=15). Groups were examined for differences between post-concussive symptoms and peri-concussive factors. Setting Outpatient clinic. Participants 37 concussed adolescents age 12–17 with persisting concussion symptoms were assessed. Concussion diagnoses were indicated by traumatically induced alterations in mental status (with or without LOC), disruption in brain functioning (memory loss/neurological deficits), and other physiologic symptoms post-concussion. Those with baseline psychiatric history and/or special education were excluded. Assessment of risk factors Post-concussive symptom variable relationships were assessed. Outcome measures group differences were analysed using ANOVAs. Results No differences between positive LOC, positive amnesia, or post-concussive criteria existed, indicating likely comparable severity. While there were no group differences for number of concussions, headaches, or nausea, those in EMO were significantly more likely to endorse photo-sensitivity (p=0.003, F=10.155) and phono-sensitivity (p=0.007, F=8.108). Both anxiety and irritability/aggression were significantly (p<0.05) correlated with endorsement of attention difficulties (r=0.332, r=0.474, respectively). Family psychiatric history was not correlated with emotional difficulties post-concussion. Conclusions Results indicate that adolescents who self-report emotional difficulties following sports concussion are more likely to endorse some physical symptoms, particularly photo-sensitivity and phono-sensitivity. Those experiencing anxiety or irritability are also more likely to experience increased attentional difficulties. Competing interests None.