Development of a composite orthopaedic pain scale in horses

This study addresses development and validation of a composite multifactorial pain scale (CPS) in an experimental equine model of acute orthopaedic pain. Eighteen horses were allocated to control (sedation with/without epidural analgesia - mixture of morphine, ropivacaine, detomidine and ketamine) and experimental groups: amphotericin-B injection in the tarsocrural joint induced pain and analgesia was either i.v. phenylbutazone administered post-induction of synovitis, or pre-emptive epidural mixture, or a pre-emptive combination of the 2. Inter- and intra-observer reproducibility was good (0.8相似文献   

Retrospective study of the risk factors and prevalence of colic in horses after orthopaedic surgery

The records of 496 orthopaedic operations on 428 horses were reviewed to estimate the prevalence of, and identify the risk factors for, the development of colic in horses after surgery. Colic was defined as any recognised sign of abdominal pain that could not be attributed to a concurrent disease. Fourteen of the horses developed colic; eight of them were undiagnosed, three were classified as impactions, one as tympanic colic of the colon, one as incarceration of the small intestine in the epiploic foramen, and one as left dorsal displacement of the colon in the nephrosplenic space. Morphine was associated with a four-fold increased risk of colic compared with the use of no opioid or butorphanol, and out-of-hours surgery was also associated with an increased risk.     

Metabolic and clinical traits in horses undergoing feed deprivation for elective orthopaedic surgery

The objective of this study was to investigate some metabolic and clinical effects of feed deprivation in horses that were submitted for orthopaedic surgery. The effects of preoperative feed restriction were investigated in 20 horses submitted for elective orthopaedic surgery.The patients were fasted from 12 hours before until 4 hours after surgery. Serum free amino acids, glucose,free fatty acids (FFA), white blood cell counts, creatine kinase (CK) and aspartate aminotransferase (AST) were determined 24 hours before surgery, 2 hours after the end of anaesthesia and 24 and 72 hours after surgery. Besides, abdominal sounds, appetite, faecal quality and body temperature were examined. Serum free amino acids did not react homogenously, concentrations were partly increasing or decreasing. Plasma glucose and FFA increased after surgery and returned to their preoperative levels 72 hours after surgery. A significant rise of the segmented granulocytes occurred 24 hours after surgery, all other parameters of the leukogram did not exceed the physiological range. AST reached its highest activity 24 hours after surgery, whereas CK activities were highest at 2 hours after surgery. Abdominal sounds were significantly reduced until 24 hours after surgery, however, appetite was not depressed. Faecal quality was physiological after surgery. Mean body temperature stayed within the physiological range. In conclusion, a relatively short perioperative fasting period had significant effects on the metabolic traits in horses, however the effects on physiological functions were minor. The consequences of major surgical procedures need to be addressed in future studies.     

Preliminary evaluation of a behaviour-based system for assessment of post-operative pain in horses following arthroscopic surgery

Objective To develop a method for objective assessment of equine post‐operative pain. Study design Prospective nonblinded clinical study. Animals Twelve adult horses: Group 1 (G1, n = 6), admitted for arthroscopy (under general anaesthesia, with multimodal analgesia); Group 2 (G2, n = 6), ‘pain free’ controls. Materials and methods Horses were filmed continuously (CVI, time‐lapse video recorder) over 72 hours, from 24 hours pre‐surgery (PS) to 48 hours post‐recovery (PR) (G1), and over 24 hours (G2). Activity budgets were determined from 24 to 0 hours PS, 0–24 and 24–48 hours PR (G1) and for 24 hours (G2). Using direct observation (DO), active behaviours and postures were recorded at set time points PS and PR (G1) and at two time points (morning/evening) (G2). Heart rate (HR) and respiration rate (RR) were recorded simultaneously. Statistical analysis investigated within‐group and between‐group time‐related changes in behaviour, HR and RR. Results There was no difference in HR or RR between G1 and G2 at any time point. Anaesthetic ‘hangover’ and hunger‐related activity modulated behaviour from 0 to 6 hours PR, when abnormal postures and locomotion occurred in all G1 horses, but no G2 horses. Compared with G1 (0–24 hours PR), G2 spent more time eating (t = ?3.34, p < 0.01), more time at the front of the stable (t = ?2.42, p < 0.05), and less time exhibiting ‘abnormal’ behaviour (U = 56, p < 0.01). Comparing PS and PR behaviour, G1 spent less time exploring from 24 to 48 hours PR (t = 3.49, p < 0.05), less time in sternal recumbency (t = ?3.8, p < 0.05) and less time moving (t = 3.19, p < 0.05). Horses tended (p < 0.07) to spend less time positioned in the front of the stable PR (less from 24 to 48 hours PR than from 0 to 24 hours PR). Comparing PR (evening) behaviour, G2 spent more time with head above withers (U = 21.5, p < 0.01), and ears forwards (U = 22, p < 0.01). G1 showed time‐related changes (all p < 0.05) in time with lower lip tense (S = 15.8), eating (S = 17.08) and with head positioned above withers (S = 18.04). No differences in event behaviours were observed between G1 and G2. Within G1, only olfactory behaviour varied significantly with time (S = 14.52, p < 0.05). Conclusions Changes in equine behaviour suggestive of post‐operative discomfort were identified using both DO and CVI. Analysis of activity budgets may be a more sensitive method of identifying behavioural changes indicative of equine discomfort than repeated DO of specific events and postures.     

Preliminary evaluation of subjective scoring systems for assessment of postoperative pain in horses

This study examined the performance of two subjective pain scoring systems for evaluating equine postoperative pain, and investigated differences in pain scoring tendencies of veterinarians and grooms. Fifteen horses were included in the study. Group 1 (n = 8) had chronic lameness and was admitted for elective arthroscopy under general anaesthesia, on one or two femoropatellar, femorotibial or tibiotarsal joint or digital flexor tendons. The anaesthetic protocol for each horse was similar but not standardized. Multi‐modal peri‐operative analgesia comprised: romifidine (100 µg kg^?1 IV); flunixin (1.1 mg kg^?1 IV); ketamine (2.2 mg kg^?1 IV); morphine (0.12 mg kg^?1 IV); phenylbutazone (4 mg kg^?1 IV/PO). Group 2 (n = 7) included pain free controls. At 6 hours post‐recovery from anaesthesia (PR) (group 1) or at 20.00 hours (group 2 with one limb bandaged), horses were filmed undisturbed in their stables for 90 seconds (dynamic behaviour, DB); thereafter, the surgery site and pharynx of each horse were palpated (and filmed) in a standardized manner (interactive behaviour, IB). Two observer groups, seven veterinarians and eight grooms, watched video footage of each horse and assigned pain scores using a visual analog scale (VAS) and a numerical rating scale (NRS). Observers assigned a pain score (VAS and NRS) for DB and IB separately and overall. Statistical analysis (Minitab 13.0, Wilcoxon signed rank and Mann–Whitney U‐tests) investigated differences in pain scores attributed to groups 1 and 2 horses, compared pain scores assigned by veterinarians and grooms, and examined differences in the performance of VAS and NRS techniques. There were significant differences in the pain scores assigned by veterinarians and grooms to groups 1 and 2 horses. When using DB or IB separately (but not combined) to score perceived pain, grooms assigned higher scores to group 1 than group 2 (U = 81.5, p < 0.05; U = 82.0, p < 0.05) using the VAS. There was no difference in NRS scores attributed by grooms to groups 1 and 2. Using DB and IB separately or combined, there was no difference in pain scores attributed to groups 1 and 2 by veterinarians using either VAS or NRS scoring systems. Using separate VAS scores for DB (W = 32.5, p < 0.05) and IB (W = 26.5, p < 0.05) and using combined (DB + IB) VAS scores, grooms awarded higher pain scores (W = 27.0, p < 0.05) than veterinarians to group 1. Using the NRS, vets and grooms did not score pain differently for group 1. For group 2, grooms scored pain significantly higher than vets when using the VAS to score IB separately (W = 21.0, p < 0.05); no other differences between grooms and veterinarians in pain scoring of group 2 (NRS or VAS, DB and IB separately or combined) were identified. The performance of subjective pain scoring systems for assessment of equine postoperative pain varies according to the scale used, the behaviour evaluated (dynamic or interactive) and the observer group. While data suggest that grooms distinguished post‐surgery horses from controls more successfully than vets and assigned higher pain scores to these horses, the specific behavioral criteria on which scores were assigned requires future investigation and identification.     

In vitro comparison of three fixation methods for humeral fracture repair in adult horses

The stiffness, load to failure, and bending moments of adult intact equine humeri and humeri repaired with 3 fixation techniques were determined in vitro. Bones were tested in axial compression (30 pairs), mediolateral 3-point bending (15 pairs), and caudocranial 3-point bending (15 pairs). An oblique osteotomy of 1 humerus of each pair was performed to simulate the long spiral oblique fractures that occur clinically in horses. Bones were repaired in 3 ways: group 1--nylon band cerclage fixation (20 bones); group 2--multiple intramedullary pinning (20 bones); and group 3--nylon band cerclage fixation and multiple intramedullary pinning (20 bones). Intact bones were significantly (P less than 0.05) stronger than repaired bones in each testing mode. Bones repaired with bands only were significantly less stiff in bending than were bones repaired with pins only or with pins and bands. In compression, only specimens repaired with pins and bands were significantly stiffer than were bones repaired with bands only. Bones repaired with bands only required significantly less load to failure in compression and in caudocranial bending than did bones repaired with pins only or with pins and bands. Bones repaired with pins only deformed through the full displacement of the actuator (5 cm), and pins deformed plastically. Bones repaired with pins and bands were stiffer and had higher bending moments than did bones repaired with pins only, but the differences were not significant.     

Anti-nociceptive efficacy of carprofen, levomethadone and buprenorphine for pain relief in cats following major orthopaedic surgery

A placebo-controlled, randomized blind study was conducted in cats (n = 60) after fracture repair to compare the analgesic effects as well as the side-effects of carprofen, buprenorphine and levomethadone during a 5-day treatment. Cats with severe shock symptoms or increases in blood urea nitrogen (BUN) and creatinine were excluded from the study. The cats were randomly assigned to four groups (n= 15). In group 1, carprofen was administered upon extubation at an initial dose of 4 mg/kg body weight, followed by one-third of that dose three times daily on days 2 to 5. In group 2, buprenorphine was administered in a single dose of 0.01 mg/kg body weight upon extubation and subsequently every 8 h. Levomethadone (group 3) was applied according to the same scheme at a dosage of 0.3 mg/kg body weight each time. The placebo (group 4) was given at the same time intervals as the opioids. Examinations were carried out prior to anaesthesia, between 30 min and 8 h after extubation, and on the following 4 days, 1 h after administration of the analgesics or the placebo as well as 1 h before the next administration. Pain and sedation evaluation was carried out with a visual analogue system (VAS) and with the aid of a numerical estimation scale (NRS). Pain was also scored by measuring mechanical nociceptive threshold of traumatized tissue. Plasma glucose and cortisol concentration, heart rate, respiration rate, blood pressure and body temperature were measured. Furthermore, a complete blood count and clinical chemistry including BUN, creatinine, alanine aminotransferase (ALT), glutamate dehydrogenase (GLDH), arterial blood pressure (AP), total protein and electrolytes of the cats were checked on the day of admission as well as on the last day of this study (day 5). Defaecation and urination as well as wound healing were monitored. On the basis of the mechanical nociceptive threshold of the traumatized tissue, concentrations of plasma glucose and cortisol and pain assessment using NRS and VAS, carprofen was found to have better anti-nociceptive efficacy when compared with the two opioid analgesics, while the analgesic effect of levomethadone was similar to that of buprenorphine. However, the carprofen group also showed comparably high median NRS and VAS pain scores in addition to occasional broad deviations from the group mean on the first post-operative treatment day. Sedative effects were detected for buprenorphine and levomethadone; in addition, symptoms of central excitation were noted with levomethadone. There was no indication of any clinically relevant respiratory depressive or cardiovascular effects, nor of any undesired renal, gastrointestinal or hepatic effects of the analgesics applied. However, the somewhat insensitive examination methods did not permit sufficient evaluation of side-effects, particularly on the gastrointestinal tract and the kidneys. It was found that carprofen and buprenorphine were well-tolerated analgesics for a 5-day administration in the cat, whereas levomethadone caused central excitation in some cases in the dosage scheme used here. However, it was apparent that none of the tested analgesics induced sufficient analgesia in the post-operative phase. For this reason, suitable methods must be found to improve analgesia, particularly in the immediate post-operative phase.     

A comparison of xylazine-ketamine and detomidine-ketamine anaesthesia in horses

Anaesthesia produced by xylazine (1.1 mg/kg IV) followed in 3–5 minutes by ketamine (2.2 mg/ kg IV) (X / K) was compared to anaesthesia produced by detomidine (0.02 mg/kg IV) followed in 15–25 minutes by ketamine (2.2 mg/kg IV) (D/K) in the same six horses. Quality of induction, recovery, muscle relaxation, coordination (before and after anaesthesia) and response to stimulus were subjectively evaluated. Heart rate, respiratory rate, mean blood pressure, hemoglobin saturation, arterial pH, CO₂ and O₂ were monitored. Recumbency time and number of attempts required to stand were recorded. Recumbency time was longer in all horses with X/K (median recumbency time of 27 min) than with D/K (median recumbency time of 22 min). No significant differences between treatments were seen for any other variable measured, although 2 horses did not appear to reach a surgical plane of anaesthesia with D/K.     

Use of blood culture medium enrichment for synovial fluid culture in horses: A comparison of different culture methods

Reasons for performing study: Standard methods for culturing equine synovial fluid (SF) are often unrewarding. Evidence‐based information on the relative efficiency of different systems used for optimisation of isolation of microorganisms from equine SF is lacking. Objectives: To compare the results of different culture systems performed in parallel on SF samples from horses clinically diagnosed with synovial sepsis. Methods: Synovial fluid specimens were collected between February 2007 and October 2008 from all horses admitted to a referral hospital that were clinically diagnosed with synovial sepsis and from control horses. Synovial fluid samples were cultured in parallel by: 1) direct agar culture (DA); agar culture after: 2) lysis‐centrifugation pretreatment (LC); 3) conventional enrichment (CE); 4) combined LC/CE; or 5) blood culture medium enrichment using an automated system (BACTEC 9050). Results: Ninety SF samples from 82 horses were included, together with 40 control samples. Seventy‐one of 90 samples (79%) were culture‐positive by using blood culture medium enrichment (BACTEC), which was significantly higher compared to all other methods. BACTEC enrichment was never negative while any of the other methods was positive. Although agar culture following LC and/or CE resulted in a slightly higher number of positive samples compared to DA, this difference was not significant. All control samples were culture negative by the 5 different techniques. Although the majority of samples containing isolates recovered without enrichment, culture results after BACTEC enrichment were available on the same day as for agar culture with or without LC (19/23 samples), while CE postponed recovery by at least one day in 20/23 samples. Conclusion: Blood culture medium enrichment is superior to other techniques for isolation of bacteria from SF of horses. The use of an automated system allows enrichment without substantially postponing recovery of microorganisms. Potential relevance: The efficient and fast isolation of microorganisms from infected SF by the BACTEC system allows for rapid susceptibility testing and a more appropriate antibiotic treatment.     

A comparison of N-butylscopolammonium and lidocaine for control of rectal pressure in horses

In its FDA approved formulation, N-butylscopolammonium bromide (Buscopan Injectable Solution, Boehringer Ingelheim Vetmedica) is an anticholinergic spasmolytic agent indicated for management of abdominal pain associated with spasmodic colic, flatulent colic, and simple impactions in horses. Use of this drug ablates gastrointestinal peristalsis and rectal pressure. It ahs been suggested that N-butylscopolammonium bromide could be used to facilitate rectal examinations in horses. This study compared the effects of N-butylscopolammonium bromide versus lidocaine and a saline control on rectal pressure and the number of rectal strains during rectal examination. The results of this study indicate that this drug increases the quality and, presumably, the safety of rectal examinations in horses.     

Recognition and quantification of pain in horses: A tutorial review

Pain management is dependent on the quality of the pain evaluation. Ideally, pain evaluation is objective, pain‐specific and easily incorporated into a busy equine clinic. This paper reviews the existing knowledge base regarding the identification and quantification of pain in horses. Behavioural indicators of pain in horses in the context of normal equine behaviour, as well as various physiological parameters potentially useful for pain evaluation, are discussed. Areas where knowledge is sparse are identified and a new equine pain scale based on results from all reviewed papers is proposed. Finally, the most important considerations in relation to the implementation of a pain scale in a hospital setting are discussed.     

A review of post-operative infections in veterinary orthopaedic surgery.

Surgical site infections are an inherent risk in orthopaedic surgery and many of the infections that develop are likely to be non-preventable. However, a variety of measures can be undertaken to reduce the risk and impact of surgical site infections. The development and implementation of an infection control program, including surgical site infection surveillance, can be an important tool for patient management. All veterinary practices should have some form of infection control program in order to address surgical site infections, among other issues, and to provide the optimal and expected level of care.     

A field evaluation of anthelmintics in horses in Sweden

A field evaluation of anthelmintics in 336 horses on 37 farms was conducted between February and May 1986 in Sweden. The herds, each comprising at least eight horses, had histories of grazing on permanent pastures and receiving regular treatments against parasites at least three times a year. Small strongyles were refractory to (pro)-benzimidazole drugs in all but one of 23 herds examined. There was an average reduction in egg output of approximately 60%, and approximately 30% of 205 horses examined were shedding less than 100 eggs g-1 7 days after treatment. There was great between-herd variation of both the faecal egg-count depression (6.4-90.4%) and drug efficacy (0.0-80.0%). The non-benzimidazole drugs under investigation were fully effective against mature small strongyles.     

Use of opioids for pain and anesthetic management in horses.

REGIONAL ADMINISTRATION: There is limited, but convincing, evidence that epidural administration of morphine and some other mu-agonist opioids consistently relieves regional pain in horses. In addition, this effect is not accompanied by notable undesirable effects. On the other hand, a clinically important analgesic action has not been demonstrated for similarly administered kappa-agonist opioids. There has been little objective data presented to support the analgesic effectiveness of intra-articularly administered opioids in horses. However, the evidence of local opioid receptors legitimately encourages work to substantiate the value of intra-articular opioid administration to relieve joint-associated pain in horses. SYSTEMIC ADMINISTRATION: So far, study results do not provide convincing, objective evidence to support the opinion that systemically administered opioids consistently and effectively relieve pain in horses. Given this lack of evidence, and considering that opioids stimulate locomotor and other forms of unwanted excitant behavior, reduce propulsive gastrointestinal motility, decrease alveolar ventilation (especially in association with general anesthesia), and require regulatory and practical considerations for abuse potential in both humans and horses, we conclude that routine, indiscriminate administration of opioids for pain relief in horses is not justified. Identification and focused, objective study of selective beneficial opioid actions to provide guidance for appropriate clinical use is long overdue.     

The use of computed tomography to assist orthopaedic surgery in 86 horses (2002–2010)

Imaging‐assisted orthopaedic surgery is becoming part of routine orthopaedic practice in horses and several techniques have been reported. However, there are no published reports describing the use of intraoperative computed tomography (CT) for surgical guidance and immediate post operative control in the horse. This use of CT in equine orthopaedics is currently limited because of the logistic problems associated with availability of CT scans in surgical theatres as well as concerns over radiation safety. The aim of this report was retrospectively to report CT assisted orthopaedic surgical cases in our practice through identifying the types of surgery where it was used, to list the technical problems that were encountered, to describe solutions to these, and to discuss the applications of the technique. All surgical procedures were performed with the assistance of a peripheral quantitative computed tomography (pQCT) scanner. CT assisted orthopaedic surgery in 86 patients during the study period. Reasons for CT included: 1) use of CT at the beginning of the surgical procedure to document the lesion and identify surgical landmarks (n = 75); 2) pre, intra‐ and post operative use of CT in comminuted fractures of the middle or proximal phalanx to guide and control internal fixation (n = 7); and 3) post operative use of CT to monitor the results of the surgical procedure (n = 4). Proper planning in both the draping steps and the use of polyvinyl splints to stabilise the limb allowed for movements of the gantry around the limb. The time required to obtain one slice was not dissimilar to the time that is necessary to take and process a single digital radiograph. The radiation dose with the pQCT described here is <0.5 µSv and its acquisition time should be balanced against radiation risks of conventional CT systems.     

Diagnostic ultrasonography for evaluation of cryptorchidism in horses

The location and size of 11 retained testes were accurately determined ultrasonographically. There was 100% correlation between the location of the testis determined by ultrasound vs that determined by surgery. Testicular size determined presurgically in all cases closely approximated the actual size obtained by gross measurement of the excised testis. The cryptorchid testicular echotexture was less dense than that of the normal descended testicles, but was easily identified. Ultrasonographic evaluations were completed by use of an ultrasound base unit with attached 5-MHz transrectal transducer. Rectal scans were started at the pelvic brim and continued in a to-and-fro pattern between the midline and the lateral abdominal wall. When the testis was located, the image was froze to allow measurement. All testicular locations were ascertained ultrasonographically either by rectal or external inguinal scans.