Use of a pool-raft system for recovery of horses from general anesthesia: 393 horses (1984-2000)

OBJECTIVE: To describe the pool-raft recovery system protocol and to evaluate the clinical outcome in horses that underwent recovery from general anesthesia using this system. DESIGN: Retrospective study. ANIMALS: 393 horses that underwent recovery from general anesthesia in the pool-raft system. PROCEDURE: Anesthetic records were examined from horses recovered from anesthesia in the pool-raft system between January 1984 and December 2000. Complete medical records of horses were examined when available. Information regarding the anesthetic and recovery period was recorded. Horses first recovered from general anesthesia in the pool-raft and, once awake, were transported to a recovery stall and lowered to the floor in a standing position. RESULTS: 351 horses underwent 1 pool-raft recovery, and 42 horses underwent multiple pool-raft recoveries. Most horses were recovered from general anesthesia within the pool-raft system to safeguard repair of a major orthopedic injury. During 471 pool-raft recoveries, 34 (7%) horses had complications within the recovery pool and 62 (13%) had complications within the recovery stall. Deaths resulted from complete failure of internal fixation, pulmonary dysfunction, or a combination of pulmonary dysfunction and fixation failure in 2% (10/471) of horses that underwent pool-raft recoveries. CONCLUSIONS AND CLINICAL RELEVANCE: The pool-raft system is a good option for recovery from general anesthesia. Although not a fail-safe system, it appears to decrease the complications of recovering horses in a high-risk category. Potential disadvantages of this system are added expense and manpower necessary in building, maintenance, and usage, as well as size limitations of the raft itself.     

Use of the Anderson Sling suspension system for recovery of horses from general anesthesia

OBJECTIVE: To describe a sling recovery system (Anderson Sling) for horses and to evaluate outcome of high-risk horses recovered from general anesthesia by a sling. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Horses (n=24) recovered from general anesthesia. METHODS: Complete medical and anesthetic records (1996-2003) for horses recovered from general anesthesia using the Anderson Sling system were evaluated retrospectively. Information retrieved included anesthetic protocol, surgical procedure, recovery protocol, recovery time, and quality of the recovery. Horses were recovered from anesthesia supported by the Anderson Sling in a standing position within a traditional padded equine recovery stall. RESULTS: Twenty-four horses had 32 assisted recoveries; 31 events were successful. No complications associated with the sling or recovery system protocol occurred. One horse was intolerant of the sling's support and was reanesthetized and recovered successfully using head and tail ropes. CONCLUSION: The Anderson Sling recovery system is an effective and safe way to recover horses that are at increased risk for injury associated with adverse events during recovery from general anesthesia. CLINICAL RELEVANCE: The Anderson Sling system should be considered for assisted recovery of equine patients from general anesthesia.     

Questionnaire on the process of recovering horses from general anesthesia and associated personnel injury in equine practice

ObjectiveTo collect data about the current practice of recovering horses from general anesthesia and recovery personnel safety.Study designOnline survey.MethodsAn online questionnaire, including questions on general demographic data, recovery drugs, modality and characteristics of equine recovery and morbidity and mortality, was designed and distributed via e-mail to equine practitioners worldwide.ResultsPractitioners from 22 countries completed 373 questionnaires; 53% of the participants were board-certified equine surgeons, and the remainder were board-certified anesthesiologists (18%), large animal residents (8%), general practitioners (7%), large animal interns (6%), anesthesia residents (4.5%) and veterinary technicians (1.6%). Respondents were employed by academia (58%) or private practice (42%). Of the respondents employed at a university, 93% had a board-certified anesthesiologist on staff compared with 7% of respondents employed at a private practice. Most of the respondents assist horses during recovery, with 23% assisting every recovery and 44% assisting recovery in the majority of cases. Reasons for choosing to assist horses during recovery were: orthopedic procedures (57%), neurological deficits (49%), bad health (47%), history of poor recovery (44%), foals (42%), draft breeds (30%), magnetic resonance imaging (17%) and computed tomography (16%). Unacceptable recoveries were reported by 77% of participants. Commonly reported complications during recovery with any method were: orthopedic injury (66%), myopathy (54%), skin abrasion (53%) and airway obstruction (37%). The incidences of unacceptable quality of recovery (p = 0.09) or personnel injury (p = 0.56) were not different between assisted and nonassisted recoveries; however, more equine fatalities were reported for assisted recoveries (p < 0.006). Practitioners in academia reported more unacceptable recoveries (p < 0.0007) and personnel injuries (p < 0.002) compared with those in private practice.ConclusionsThe method of recovery differs among hospitals. Recovery personnel injuries associated with assisting horses during recovery are an important and previously unreported finding.     

Use of a hydro-pool system to recover horses after general anesthesia: 60 cases

OBJECTIVE: To report complications observed using a hydro-pool recovery system after general anesthesia in horses. STUDY DESIGN: Retrospective study. ANIMALS: Sixty horses. METHODS: Retrospective review of the medical records and quality of recovery from anesthesia of 60 horses that had surgical or diagnostic procedures under general anesthesia. RESULTS: Mean total anesthesia time was 182 minutes (range, 25 to 390 minutes). Mean time in the hydro-pool was 108 minutes (range, 20 to 270 minutes). One horse that had bilateral rear limb extensor weakness while recovering in a padded recovery stall was moved to the hydro-pool and maintained for 12 hours. Ten horses developed some pulmonary edema; in 3 horses, the signs of pulmonary edema were severe; and 1 horse died from related complications. One horse developed septic arthritis of an operated stifle joint, and 2 horses developed incisional infections. Two horses incurred multiple skin abrasions on the distal aspect of their limbs during violent attempts to leave the pool. CONCLUSIONS: A hydro-pool system was useful for recovering horses from general anesthesia when difficult recoveries were anticipated because of the horse's injury, size, demeanor, duration of anesthesia, or risk of further injury. Recovery using the hydro-pool was more time and labor intensive than a standard stall recovery. Pulmonary edema that required treatment was a serious complication that occurred in 17% of the horses. Careful closure of the skin with cyanoacrylate glue and pressure from bandages were used to prevent postoperative incisional infections. CLINICAL RELEVANCE: A hydro-pool system is a useful method for recovering horses from general anesthesia when difficult recoveries are anticipated.     

Management and complications of anesthesia for transvenous electrical cardioversion of atrial fibrillation in horses: 62 cases (2002-2006)

OBJECTIVE: To describe management of anesthesia for transvenous electrical cardioversion (TVEC) in horses and report perianesthetic complications. DESIGN: Retrospective case series. ANIMALS: 62 horses with atrial fibrillation and without underlying cardiac disease and 60 horses without atrial fibrillation. PROCEDURES: Medical records of horses with atrial fibrillation anesthetized for TVEC were reviewed, as were records of horses without atrial fibrillation anesthetized for magnetic resonance imaging (MRI). The TVEC group horses were compared with MRI group horses for incidence of intraoperative bradycardia and use of inotropic drugs. Data obtained included patient signalment, weight, duration of anesthesia, heart rate and arterial blood pressure during anesthesia, anesthetic drugs administered, mode of ventilation, perioperative complications, and quality of recovery. RESULTS: The TVEC group horses were > 1 year of age and were predominantly Standardbreds. The TVEC group horses underwent a total of 76 anesthetic episodes. For 40 (52.6%) anesthetic episodes, horses received xylazine only for premedication, and for 26 (34.2%) anesthetic episodes, horses received xylazine and butorphanol. Induction of anesthesia consisted of ketamine administration in various combinations with diazepam and guaifenesin for 74 (97.4%) anesthetic episodes and ketamine alone for 2 (2.6%). Bradycardia in horses was encountered during 15 of 76 (19.7%) anesthetic episodes. Minor signs of possible postanesthetic myopathy occurred following 6 (7.9%) anesthetic episodes. No significant difference was found between TVEC and MRI group horses regarding incidence of bradycardia and inotropic drug administration. CONCLUSIONS AND CLINICAL RELEVANCE: Short-duration anesthesia for TVEC of atrial fibrillation in horses without underlying cardiac disease was a safe procedure.     

Anesthesia of the intensive-care patient

Mortality rates for healthy horses undergoing general anesthesia for routine procedures have been reported to range from 0.6% to 1.8%; these numbers increase as high as 5% when systemically ill horses are included in calculations. Anesthesia of intensivecare equine patients should first include critical assessment of the need for versus risk of anesthetic intervention. When general anesthesia cannot be avoided, the following measures should be considered and addressed throughout the perianesthetic period: preanesthetic assessment and cardiopulmonary stabilization, perianesthetic oxygen supplementation and ventilatory support, vigilant monitoring of the cardiopulmonary system, supportive therapy (ie, inotropic agents, fluids) to promote adequate cardiac output, use of perioperative adjunct systemic and/or regional agents to reduce inhalant requirements, close observation and assistance during recovery, and postoperative analgesia.     

Comparison of recoveries from anesthesia of horses placed on a rapidly inflating-deflating air pillow or the floor of a padded stall

OBJECTIVE: To compare recoveries from anesthesia of horses placed on a conventional padded stall floor or on a specially designed air pillow. DESIGN: Prospective study. ANIMALS: 409 horses (> 1 year old) that were anesthetized for surgical procedures during a 37-month period. PROCEDURES: By random allocation, horses were allowed to recover from anesthesia in either a foammat-padded recovery stall or an identical recovery stall equipped with a rapidly inflating-deflating air pillow. All recoveries were videotaped for subsequent analysis by an independent evaluator. Times to first movement, first attempt to attain sternal recumbency, attainment of sternal recumbency, first attempt to stand, and successful standing were recorded. The numbers of attempts before achieving sternal recumbency and standing were counted, and scores for quality of standing and overall recovery were assigned. Recovery-related variables were compared between groups. RESULTS: Compared with horses allowed to recover in a conventional manner, horses that recovered from anesthesia on the air pillow had a significantly longer rest period before attempting to attain sternal recumbency and rise to standing. Once the pillow was deflated, horses were able to stand after significantly fewer attempts and the quality of their standing was significantly better. Between the 2 groups of horses, there was no significant difference in overall recovery quality scores. The air pillow and padded floor systems were equally safe. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that use of a rapidly inflating-deflating air pillow promotes a longer period of recumbency and a better quality of standing after anesthesia in horses.     

Risk of anesthesia-related complications in draft horses: a retrospective,single-center analysis

ObjectiveTo report anesthetic-related complications and determine risks associated with anesthesia in draft horses.Study designRetrospective study.AnimalsA total of 401 anesthetic records for draft horse breeds that underwent general anesthesia from January 2010 through December 2020 were reviewed; horses euthanized during general anesthesia were excluded.MethodsDemographics, perioperative drugs used, procedure type and duration, time to extubation, number of attempts to stand, use of sling in recovery and perioperative morbidity and mortality were investigated. Morbidity and mortality statistical evaluation included univariable logistic regression analysis and ordinal regression analysis.ResultsAmerican Society of Anesthesiologists (ASA) status I–II, ASA III–V and total mortality rate for all cases was 0.69% (2/288), 6.19% (7/113) and 2.24% (9/401), respectively, with Belgian horses being overrepresented (6/9). Cardiac arrest occurred in six out of nine horses that died without euthanasia, and five out of six of these horses underwent colic surgery. Factors associated with increased mortality risk included ASA status of III–V, increased body weight, emergency status and horses presenting for colic. Hypotension, hypercarbia and hypoxemia occurred in 56% (224/401), 46% (186/401) and 14% (58/401) of horses, respectively. During recovery from anesthesia, lighter horses and horses undergoing shorter anesthetic procedures were more likely to be successful on the first or second attempt to stand and were less likely to require a sling in recovery.Conclusions and clinical relevanceDraft horses undergoing general anesthesia had a higher mortality rate than previously reported for all types and breeds of horses.     

Colic Surgery in Horses: A Retrospective Study Into Short- and Long-Term Survival Rate,Complications and Rehabilitation toward Sporting Activity

Colic surgery in horses impacts both short-term well-being of horses due to possible surgical and anesthetic complications and also long-term return to a sporting career. In this retrospective study, survival and complication rates, as well as functional outcome and behavioral problems in horses that underwent colic surgery were studied. Data from 283 horses that underwent colic surgery at a veterinary teaching hospital were analyzed. Furthermore, owners were contacted and requested to fill out a questionnaire concerning the first year of rehabilitation. Of 283 horses that underwent colic surgery, 167 (59%) were discharged home. After discharge from hospital, 34 horses (12%) were lost to follow-up. Of the remaining 133 horses, 128 were still alive after 1 year (96.2%), while 5 horses were euthanized due to recurrent colic. Of the horses that did not survive the hospitalization period 73 horses (25.8%) were euthanized intraoperatively and 36 horses (12.7%) during intensive care unit (ICU) stay. Survival of horses entering the ICU up to discharge from hospital was 79.5%. During rehabilitation, 49 horses (59.8%) that returned home experienced one or more recurrences of colic. Fifty-two horses (63.4%) that returned home reached at least preoperative level of performance. Altered behavior and gait-related problems during specific elements of riding (for instance during collecting, lateral bending, etc.) were reported in up to 46.2% of horses. Improving veterinary aftercare in collaboration with other disciplines (e.g., physiotherapy and saddle fitting) during rehabilitation could be a means to further improve athletic performance and welfare after recovery from colic surgery.     

Use of sevoflurane for anesthetic management of horses during thoracotomy

OBJECTIVE: To evaluate sevoflurane as an inhalation anesthetic for thoracotomy in horses. ANIMALS: 18 horses between 2 and 15 years old. PROCEDURE: 4 horses were used to develop surgical techniques and were euthanatized at the end of the procedure. The remaining 14 horses were selected, because they had an episode of bleeding from their lungs during strenuous exercise. General anesthesia was induced with xylazine (1.0 mg/kg of body weight, IV) followed by ketamine (2.0 mg/kg, IV). Anesthesia was maintained with sevoflurane in oxygen delivered via a circle anesthetic breathing circuit. Ventilation was controlled to maintain PaCO2 at approximately 45 mm Hg. Neuromuscular blocking drugs (succinylcholine or atracurium) were administered to eliminate spontaneous breathing efforts and to facilitate surgery. Cardiovascular performance was monitored and supported as indicated. RESULTS: 2 of the 14 horses not euthanatized died as a result of ventricular fibrillation. Mean (+/- SD) duration of anesthesia was 304.9 +/- 64.1 minutes for horses that survived and 216.7 +/- 85.5 minutes for horses that were euthanatized or died. Our subjective opinion was that sevoflurane afforded good control of anesthetic depth during induction, maintenance, and recovery. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of sevoflurane together with neuromuscular blocking drugs provides stable and easily controllable anesthetic management of horses for elective thoracotomy and cardiac manipulation.     

Pulmonary gas exchange and plasma lactate in horses with gastrointestinal disease undergoing emergency exploratory laparotomy: a comparison with an elective surgery horse population

Objective: To characterize pulmonary gas exchange and arterial lactate in horses with gastrointestinal disease undergoing anesthesia, compared with elective surgical horses, and to correlate these variables with postoperative complications and mortality. Study Design: Prospective clinical study. Animals: Horses undergoing emergency laparotomy for acute intestinal disease (n=50) and healthy horses undergoing elective surgery in dorsal recumbency (n=20). Methods: Arterial blood gas analysis was performed at predetermined intervals on horses undergoing a standardized anesthetic protocol. Alveolar–arterial oxygen gradient was calculated. Predictive factors for postoperative complications and death in colic horses were determined. Results: Arterial oxygen tension (P_aO₂) varied widely among horses in both groups. P_aO₂ significantly increased in the colic group after exteriorization of the ascending colon. P_aO₂ and alveolar–arterial oxygen gradient were not significantly different between groups, and neither were correlated with horse outcome. Arterial lactate in recovery ≥5 mmol/L was associated with a 2.25 times greater relative risk of complications and lactate ≥7 mmol/L was associated with a 10.5 times higher relative risk of death. Conclusion: Colic horses in this population were not more likely to be hypoxemic than elective horses, nor was gas exchange impaired to a greater degree in colic horses relative to controls. Arterial lactate sampled immediately after anesthetic recovery was predictive for postoperative complications and death.     

Transpalpebral enucleation using a chain écraseur

This study was undertaken to describe the technique, complications and outcome of the use of a chain écraseur for transpalpebral enucleation in horses under general anaesthesia. We report its use in 53 horses, reviewing the subject details, reasons for enucleation, surgical technique, intra‐ and post operative complications, and long‐term outcome. Intraoperative complications included mild to moderate bleeding in 4 horses. Post operative complications included mild periorbital post operative swelling in one horse, transient head tilt in one horse and severe enterocolitis, which resulted in euthanasia in one horse; another 2 horses were subjected to euthanasia after long bone fractures that occurred during recovery from general anaesthesia and 2 horses had the prosthesis removed as a result of inflammatory reaction or infection. Long‐term outcome was available for 38 horses, 25 of which returned to their previous activities and 13 were retired. Twelve horses were lost for follow‐up. Transpalpebral enucleation using a chain écraseur is a feasible alternative to traditional enucleation techniques that can provide adequate haemostasis during transection of the optic pedicle when used properly.     

Comparison of high (5%) and low (1%) concentrations of micellar microemulsion propofol formulations with a standard (1%) lipid emulsion in horses

OBJECTIVE: To compare anesthesia-related events associated with IV administration of 2 novel micellar microemulsion preparations (1% and 5%) and a commercially available formulation (1%) of propofol in horses. Animals-9 healthy horses. PROCEDURES: On 3 occasions, each horse was anesthetized with 1 of the 3 propofol formulations (1% or 5% microemulsion or 1% commercial preparation). All horses received xylazine (1 mg/kg, IV), and anesthesia was induced with propofol (2 mg/kg, IV). Induction and recovery events were quantitatively and qualitatively assessed. Venous blood samples were obtained before and at intervals following anesthesia for quantification of clinicopathologic variables. RESULTS: Compared with the commercial formulation, the quality of anesthesia induction in horses was slightly better with the micellar microemulsion formulas. In contrast, recovery characteristics were qualitatively and quantitatively indistinguishable among treatment groups (eg, time to stand after anesthesia was 34.3 +/- 7.3 minutes, 34.1 +/- 8.8 minutes, and 39.0 +/- 7.6 minutes in horses treated with the commercial formulation, 1% microemulsion, and 5% microemulsion, respectively). During recovery from anesthesia, all horses stood on the first attempt and walked within 5 minutes of standing. No clinically relevant changes in hematologic and serum biochemical analytes were detected during a 3-day period following anesthesia. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that the micellar microemulsion preparation of propofol (1% or 5%) has similar anesthetic effects in horses, compared with the commercially available lipid propofol formulation. Additionally, the micellar microemulsion preparation is anticipated to have comparatively low production costs and can be manufactured in various concentrations.     

Evaluation of a technique for collection of cancellous bone graft from the proximal humerus in horses

OBJECTIVES: To describe a technique for collecting cancellous bone graft from the proximal humerus in horses. STUDY DESIGN: Prospective evaluation of an experimental bone graft collection technique. ANIMAL POPULATION: Eight horses, 3-15 years, weighing 495-605 kg. METHODS: Horses were anesthetized and positioned in lateral recumbency. The lateral aspect of the proximal humerus was exposed by a 7-10-cm incision extending distally from the greater humeral tubercle, followed by sharp dissection through the omotransversarius muscle and between the infraspinatus and deltoideus muscles. A 12-mm cortical defect was incrementally created in the lateral proximal humerus. Human bone graft harvesting equipment (Acumed, Beaverton, OR) was drilled through this defect to collect a core of cancellous bone. In five horses additional cancellous bone was then collected with conventional instruments. Bone samples were weighed and histologically examined. Horses were monitored and graded for quality of anesthetic recovery, incisional complications, and postoperative lameness. RESULTS: Total mean (+/-SD) surgical time for harvesting bone with the Acumed system and traditional techniques (n=5) was 38+/-6 minutes (range, 32-47 minutes). Mean cancellous bone weight collected with the Acumed system was 3.6+/-0.8 g (range, 2.0-4.6 g), and cancellous bone collected conventionally was 25.6+/-7.5 g (range, 16.8-34.2 g). Minimal incisional complications or postoperative lameness were observed. Mortality was 12.5%; one horse fractured the operated humerus during anesthetic recovery. CONCLUSION: The Acumed system provided limited cancellous bone when used with the technique described. However, the quantity of cancellous bone collected with traditional harvesting instruments was comparable to other sites used in horses. The procedure was associated with minimal postoperative incisional complications or lameness, but because one horse suffered a catastrophic humeral fracture further research is required to assess the effects of this procedure on humeral breaking strength. CLINICAL RELEVANCE: Based on the risk of catastrophic fracture, this technique cannot be recommended for use in clinical cases, especially if an unassisted recovery from general anesthesia is planned.     

Effect of anesthesia duration on the quality of recovery in horses undergoing elective and emergency surgeries using the same anesthetic protocol

The objective of this study was to investigate the effect of anesthesia duration on the quality of recovery in horses. The medical records of horses that were anesthetized and underwent surgery for elective and emergency soft tissue and orthopedic conditions from 2013 to 2019 were reviewed. Horses included in the study (N = 305) fulfilled the following requirements: all had the same premedication/induction protocol and the same balanced anesthesia for maintenance and were anesthetized by the same, experienced Board-certified anesthesiologist. A standardized anesthetic recovery score was completed for all horses to evaluate their recovery and the following interactions were assessed: age, body weight, breed, sex, American Society of Anesthesiologists status, type of surgical procedure, occurrence of hypotension, use of dobutamine, number of additional doses of xylazine/ketamine after isoflurane discontinuation, anesthesia duration, post-anesthetic sedation, and end-tidal isoflurane concentration during maintenance and at the time of transfer to the recovery room. These interactions were assessed based on the quality of recovery score using logistic regression. Duration of anesthesia (P = 0.021) and age (P = 0.003) negatively affected the quality of recovery. The odds of a worse recovery score were increased by 1.20-fold (1.03, 1.41; lower and upper limits) for every additional 30 min of anesthesia duration, while the odds of a worse recovery score were increased by 1.09-fold (1.03, 1.16) for every additional 1 y of age. In conclusion, the results of this retrospective study indicate that increasing the anesthesia duration negatively affects the quality of recovery in horses undergoing routine and emergency surgical procedures.     

Effects of hypercapnic hyperpnea on recovery from isoflurane or sevoflurane anesthesia in horses

Objective To test the hypothesis that hypercapnic hyperpnea produced using endotracheal insufflation with 5–10% CO₂ in oxygen could be used to shorten anesthetic recovery time in horses, and that recovery from sevoflurane would be faster than from isoflurane. Study design Randomized crossover study design. Animals Eight healthy adult horses. Methods After 2 hours’ administration of constant 1.2 times MAC isoflurane or sevoflurane, horses were disconnected from the anesthetic circuit and administered 0, 5, or 10% CO₂ in balance O₂ via endotracheal tube insufflation. End‐tidal gas samples were collected to measure anesthetic washout kinetics, and arterial and venous blood samples were collected to measure respiratory gas partial pressures. Horses recovered in padded stalls without assistance, and each recovery was videotaped and evaluated by reviewers who were blinded to the anesthetic agent and insufflation treatment used. Results Compared to isoflurane, sevoflurane caused greater hypoventilation and was associated with longer times until standing recovery. CO₂ insufflation significantly decreased anesthetic recovery time compared to insufflation with O₂ alone without significantly increasing PaCO₂. Pharmacokinetic parameters during recovery from isoflurane with CO₂ insufflation were statistically indistinguishable from sevoflurane recovery without CO₂. Neither anesthetic agent nor insufflation treatment affected recovery quality from anesthesia. Conclusions and clinical relevance Hypercapnic hyperpnea decreases time to standing without influencing anesthetic recovery quality. Although the lower blood gas solubility of sevoflurane should favor a shorter recovery time compared to isoflurane, this advantage is negated by the greater respiratory depression from sevoflurane in horses.     

Demographic,preoperative and anaesthesia-related risk factors for unsatisfactory recovery quality in horses undergoing emergency abdominal surgery

ObjectiveTo determine demographic, preoperative and anaesthesia-related variables that may be associated with unsatisfactory recovery quality in horses undergoing emergency abdominal surgery (colic) in an equine teaching hospital.Study designRetrospective case series.AnimalsA total of 313 horses.MethodsThe anaesthetic records of horses admitted for surgical treatment of colic between 2005 and 2018 were examined. Overall quality of recovery was assessed as dangerous, poor, fair, good or excellent. The following categories were constructed as a dichotomic variable: unsatisfactory recovery (poor and dangerous recoveries) and satisfactory recovery (excellent, good and fair recoveries). Univariable and multivariable analyses were performed to evaluate the association between all studied variables and recovery.ResultsAll recoveries were unassisted. Unsatisfactory recovery quality totalled 17.2% (3.5% and 13.7% were dangerous and poor recoveries, respectively), whereas satisfactory recoveries totalled 82.8% (26.2%, 40.9% and 15.7% were fair, good and excellent recoveries, respectively). Univariable analysis showed that unsatisfactory recoveries were associated with high preoperative packed cell volume, pain behaviour, poor premedication and induction quality, high intraoperative mean heart rate, low mean arterial blood pressure, dobutamine dose ≥1.5 μg kg^–1 minute^–1, non-administration of romifidine, long anaesthesia time and prolonged time to stand. The multivariable model showed that factors strongly associated with unsatisfactory recovery quality were dobutamine dose ≥1.5 μg kg^–1 minute^–1 [adjusted odds ratio (AOR) = 6.60; 95% confidence interval (CI), 2.91–14.96], poor premedication quality (AOR=4.60; 95% CI, 1.73–12.23) and a time to stand > 70 minutes (AOR=2.59; 95% CI, 1.13–5.91).Conclusions and clinical relevanceOur study shows that high dobutamine requirements, poor premedication quality and a prolonged time to stand are risk factors for unsatisfactory recovery quality in horses undergoing anaesthesia for colic surgery. Addressing these factors may enable clinicians to improve the quality of recovery phase.     

Clinical and clinicopathologic variables in adult horses receiving blood transfusions: 31 cases (1999-2005)

OBJECTIVE: To determine clinical and clinicopathologic abnormalities in horses administered a blood transfusion and evaluate effects of blood transfusion on these variables. DESIGN: Retrospective case series. ANIMALS: 31 adult horses that received > or = 1 blood transfusion. Procedures-Medical records of horses receiving a blood transfusion were reviewed to obtain clinical findings, laboratory test results before and after transfusion, adjunctive treatments, transfusion type and volume, response to transfusion, results of donor-recipient compatibility testing, adverse reactions, and outcome. RESULTS: 31 horses received 44 transfusions for hemorrhagic anemia (HG; n = 18 horses), hemolytic anemia (HL; 8), or anemia attributable to erythropoietic failure (EF; 5). Tachycardia and tachypnea were detected in 31 of 31 (100%) and 22 of 31 (71%) horses, respectively, before transfusion. The PCV and hemoglobin concentration were less than the reference range in 11 of 18 horses with HG, 8 of 8 horses with HL, and 5 of 5 horses with EF. Hyperlactatemia was detected in 16 of 17 recorded values before transfusion. Heart rate, respiratory rate, and PCV improved after transfusion, with differences among the types of anemia. Seventeen (54%) horses were discharged, 9 (29%) were euthanized, and 5 (16%) died of natural causes. Adverse reactions were evident during 7 of 44 (16%) transfusions, varying from urticarial reactions to anaphylactic shock. CONCLUSIONS AND CLINICAL RELEVANCE: Abnormalities in clinical and clinicopathologic variables differed depending on the type of anemia. Colic, cold extremities, signs of depression, lethargy, tachycardia, tachypnea, low PCV, low hemoglobin concentration, and hyperlactatemia were commonly detected before transfusion and resolved after transfusion.     

Outcome of medical and surgical treatment of cecal impaction in horses: 114 cases (1994-2004)

OBJECTIVE: To determine short- and long-term outcomes, including recurrence rates, for horses with cecal impaction treated medically or surgically. DESIGN: Retrospective case series. ANIMALS: 114 horses. PROCEDURES: Medical records were reviewed for information on signalment, history, clinical findings, treatment (medical vs surgical), and short-term outcome. Information on longterm outcome was obtained through a mail survey and telephone interview with owners. RESULTS: 54 horses were treated medically, 49 horses were treated surgically, and 11 horses were euthanized after initial examination without further treatment. Horses treated surgically were significantly more likely to have signs of moderate or severe pain than were horses treated medically. Forty-four of the 54 (81%) horses treated medically were discharged from the hospital. Twelve of the 49 horses treated surgically were euthanized at surgery because of cecal rupture. Thirty-five of the 37 (95%) horses that were allowed to recover from surgery were discharged from the hospital. In 34 horses treated surgically, typhlotomy without a bypass procedure was performed. Long-term (>or= 1 year) follow-up information was available for 19 horses treated medically and 28 horses treated surgically. Eighteen (95%) and 25 (89%) of the horses, respectively, were alive at least 1 year after treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that medical and surgical treatment were both associated with favorable outcomes in horses with cecal impactions. In this population, typhlotomy alone without cecal bypass was associated with a low recurrence rate. The long-term prognosis for horses that were discharged from the hospital was good.