Topic:Anesthesia
Anesthesia in horses involves the administration of drugs to induce a temporary loss of sensation or consciousness, facilitating surgical procedures and other medical interventions. This complex process requires a deep understanding of equine physiology and pharmacology to ensure the safety and well-being of the animal. Anesthesia in horses can be challenging due to their size, temperament, and unique anatomical and physiological characteristics. Common anesthetic agents used in equine practice include inhalants like isoflurane and sevoflurane, as well as injectable drugs such as ketamine and xylazine. The management of anesthesia in horses also involves careful monitoring of vital signs and the use of supportive measures to prevent complications such as hypotension, hypoventilation, and post-anesthetic myopathy. This page compiles peer-reviewed research studies and scholarly articles that explore the techniques, advancements, and clinical outcomes associated with anesthesia in equine medicine.
Hypoxia signaling in the equine small intestine: Expression and distribution of hypoxia inducible factors during experimental ischemia. Hypoxia inducible factors (HIF) are widely researched in human medicine for their role in different disease processes. The aim of this study was to investigate the expression and distribution of HIF in experimental small intestinal ischemia in the horse. Unassigned: In 14 horses under general anesthesia, segmental jejunal ischemia with 90% reduction in blood flow was induced. The horses were randomly divided into two groups of seven horses, one subjected to ischemic postconditioning (IPoC) by delayed reperfusion, and a control group (group C) undergoing undelayed reperfusion. Intestinal sample...
Successful surgical removal of a pheochromocytoma in a mare via trans-costal approach. Pheochromocytomas have been previously reported in horses, but successful antemortem diagnosis and surgical removal without recurrence of clinical signs have not been described. Objective: To report the clinical presentation, diagnostic evaluation, surgical technique, anaesthetic management and post-operative care of a mare diagnosed with pheochromocytoma. Methods: Clinical case report. Methods: An 18-year-old Quarter Horse mare presented for recurrent episodes of colic, profuse sweating, muscle fasciculations and agitation over a 2-month period. Clinical, clinicopathologic and ultrasonographi...
Standing Surgical Management of Splint Bone Fractures in 13 Horses: A Comparison to Management Under General Anaesthesia. The aim of this article was to describe the technique and outcomes of standing surgical management of splint bone fractures and to compare outcome variables and hospitalization cost to a group with similar fractures treated under general anaesthesia. Methods: It is a single-institution retrospective study. Surgical technique, surgical time, hospitalization cost and complications were retrieved from the medical records of horses treated surgically for splint bone fractures (2008-2020). Owner telephone follow-up provided data about athletic outcome, client satisfaction and cosmetic appeara...
General anesthesia does not induce ultrasonographic changes in the pleura of healthy adult horses anesthetized for elective magnetic resonance imaging. To compare thoracic ultrasonographic findings in healthy horses before and after general anesthesia for elective MRI utilizing a recently developed ultrasonographic scoring system to aid clinicians in the early identification of pneumonia following anesthesia. 13 adult horses > 3 years of age. Prior to anesthesia, horses underwent a thorough physical examination, CBC, thoracic radiography, and thoracic ultrasonography. Horses were then anesthetized for elective MRI, and thoracic ultrasonography was repeated within 3 hours after recovery. Thoracic ultrasonographic findings were scored utilizing...
Treatment of corneal ulceration and bullous keratopathy using a nictitating membrane flap in two horses. The aim of this study was to describe placement of a nictitating membrane flap as a treatment for corneal ulceration and bullous keratopathy in two horses. Methods: A 13-year-old American Saddlebred mare presented for severe corneal edema, superficial stromal ulceration, and a central bulla of the left eye. A 4-year-old Trakhener stallion also presented with a large axial bulla of the left eye with concurrent severe corneal edema and a deep stromal ulcer. Methods: A complete ophthalmic examination was performed. Samples were obtained for corneal cytology, and both horses were started on aggres...
Standing surgery among equine board certified surgeons: Survey regarding current use and trends. Publications about equine standing surgery are flourishing, however, information regarding its use and prevalence among surgeons is still limited. Objective: To determine the current use and recent trends for equine standing surgery among board certified surgeons and to identify the main reasons and limitations for performing a procedure standing. Methods: Cross-sectional survey. Methods: A 139-item questionnaire was sent by email to 733 large animal surgery Diplomates (ACVS and ECVS) from November 2020 to February 2021. The survey collected demographic information and general data regarding s...
Arterial blood gas tensions during recovery in horses anesthetized with apneustic anesthesia ventilation compared with conventional mechanical ventilation. To compare PaO2 and PaCO2 in horses recovering from general anesthesia maintained with either apneustic anesthesia ventilation (AAV) or conventional mechanical ventilation (CMV). Methods: Randomized, crossover design. Methods: A total of 10 healthy adult horses from a university-owned herd. Methods: Dorsally recumbent horses were anesthetized with isoflurane in oxygen [inspired oxygen fraction = 0.3 initially, with subsequent titration to maintain PaO2 ≥ 85 mmHg (11.3 kPa)] and ventilated with AAV or CMV according to predefined criteria [10 mL kg-1 tidal volume, PaCO2 40-45 mmHg (5.3-6.0 kP...
Effect of Volumes of Solutions on Intraocular Pressure During Intravitreal Injection of Low Dose Gentamicin in Horses With Recurrent Uveitis: A Randomized Controlled Study. Horses with recurrent uveitis can be treated by intravitreal injection of low dose gentamicin under sedation and after local anesthetic techniques including the retrobulbar nerve block. Since it is reported that retinal degeneration can be secondary to an acute increase of intraocular pressure (IOP), the current randomized controlled study was carried out in order to investigate the changes in IOP following retrobulbar anesthesia, with two different volumes of local anesthetic (lidocaine) solution (10 and 5 mL), and intravitreal injection of 6 mg gentamicin in two different volumes of solution...
Liposomal bupivacaine is both safe and effective when administered via local infiltration at surgical site and mesovarium for laparoscopic ovariectomy in mares. Liposomal local anaesthetic solutions may provide extended-duration analgesia postoperatively but have not been assessed following intra-peritoneal local infiltration in any species. Objective: To evaluate two doses of 1.33% liposomal bupivacaine (LB) versus 0.75% bupivacaine HCL (BHCl) for analgesia following laparoscopic ovariectomy in mares. Methods: Prospective cohort study. Methods: Fifteen healthy Quarter Horse mares (age 2-20 years) with normal bilateral ovarian palpation and appearance were enrolled. Horses were restrained in standing stocks and administered an α-2 agonist, butorpha...
Pain Assessment and Acute Phase Response in Donkeys Submitted to Inguinal Orchiectomy. In most animals, pain can compromise physiological functions and delay healing so, rapid detection of pain through behavior and inflammatory reaction with biomarkers are necessary. This study aimed to evaluate pain, physiological variations and Acute Phase Proteins (APP) in donkeys undergoing orchiectomy technique by inguinal access. For this research, 15 male northeastern donkeys kept in extensive management were selected, with a mean age of 4.5±3.1 years. All animals had the same anesthetic protocol, using dissociative anesthesia and local block with lidocaine, followed by orchiectomy by in...
Comparison of Four Arteries for Invasive Blood Pressure Measurements and Dixtal 2010 Oscillometric Values in Horses Anesthetized With Isoflurane: Does the Artery Matter? This study evaluated the agreement between invasive blood pressure (IBP) values measured in three different arteries and by an oscillometric device (NIBP) with the ones from the transverse facial artery (FA). Six horses (424.2 ± 40.7 kg) were sedated with xylazine (0.6 mg/kg IV), induced with ketamine (2 mg/kg IV) and midazolam (0.1 mg/kg IV), and maintained with isoflurane (1.2 MAC) for 90 minutes in lateral recumbency. FA, auricular artery (AA), lateral digital artery (LDA), and metatarsal artery (MA) were catheterized, and a standard adult cuff was placed on the tail. IBP and NIBP values w...
Minimally invasive removal of obstructive ureteral stones by intracorporeal lithotripsy in horses: 3 patients. Three client-owned horses diagnosed with obstructive ureteral stones were referred and treated in a minimally invasive manner by retrograde ureteroscopy in conjunction with electrohydraulic lithotripsy (EHL) or laser Holmium:YAG lithotripsy (HYL). For all 3 horses, additional tests revealed variable degrees of azotemia and ureteral obstruction. Ultrasound examination (2 horses) revealed a loss of cortico-medullary distinction consistent with a chronic nephropathy. Ultrasound-guided biopsy of the right kidney in 1 horse revealed moderate glomerulosclerosis and lymphoplasmacytic nephritis. A sta...
Immediate pre-operative computed tomography for surgical planning of equine fracture repair: A retrospective review of 55 cases. Fracture configuration is often more complex than is radiographically appreciable. The objective of this study is to describe the influence of pre-operative computed tomography (CT) for surgical planning in a variety of fracture types. This has not been described in previous studies. All cases with pre-operative radiographs, admitted for CT and surgical repair of a suspected limb fracture from January 2010-December 2020 were reviewed. CT was acquired under general anaesthesia in a multi-slice helical scanner; any surgery was then performed immediately. Three diplomates (two surgical; one diagn...
A multicenter retrospective case-cohort study on the prevalence of incisional morbidities in late pregnant mares following exploratory celiotomy (2014-2019): 579 cases. To report the prevalence and risk factors for incisional morbidities in late pregnant and nonpregnant/early pregnant control mares following colic surgery. Methods: Multicenter, retrospective, cohort study from January 2014 to December 2019. Methods: Two university teaching hospitals and 1 private referral center. Methods: Five hundred and seventy-nine fillies and mares ≥2 years old that underwent celiotomy. Pregnant mares (n = 54) were >240 days in gestation from the last known breeding date and were compared to control females (n = 525) undergoing colic surgery. Methods: None. Resu...
Comparing the anti-nociceptive, sedative and clinicophysiological effects of epidural detomidine, detomidine-lidocaine and lidocaine in donkeys. Epidural analgesia using the alpha-2 agonist detomidine (DE), alone or in combination with lidocaine (LD), is frequently employed for standing surgical procedures in horses, but its use has not been evaluated in donkeys. Methods: In a randomised controlled prospective trial, 24 healthy adult donkeys were assigned to four groups (n = 6), each receiving 40 μg/kg of DE, 0.22 mg/kg of LD, combined DE and LD (DELD) or 0.9% sterile normal saline epidurally. After epidural injection of each treatment, the onset, degree and duration of sedation and anatomical extension of anti-nociception were obse...
Surgical enlargement of the epiploic foramen in horses. To assess the safety and efficacy of a method for digitally enlarging the caudal aspect of the epiploic foramen (EF). Methods: Healthy horses and clinical cases of EF entrapment (EFE). Methods: Fourteen healthy horses and three clinical cases. Methods: Through a ventral midline celiotomy under general anesthesia, the EF was enlarged by digital separation of the caudal attachments of the caudate lobe of the liver from right dorsal colon, right kidney, gastropancreatic fold, and pancreas. Healthy horses were euthanized under anesthesia, and the enlarged EF was measured at necropsy. Results: The ...
Safety and accuracy of blind vs. ultrasound-guided dorsal retrobulbar nerve blocks in horses-A cadaveric study. There is limited knowledge regarding the safety and accuracy of ultrasound-guided retrobulbar nerve blocks in horses. The aim of this study was to compare these parameters between blind and ultrasound-guided injection techniques for the dorsal retrobulbar nerve block in horses. Methods: Equine cadaver heads were used to inject the retrobulbar space with contrast medium (CM). Injections were performed either blindly based on anatomic landmarks (blind group, n = 44) or under ultrasonographic guidance (US-group, n = 44), equally divided between an experienced and unexperienced operator. Needl...
Clinical and Antinociceptive Effects of Distal Inferior Alveolar Nerve Block in Ponies With Tramadol 5% or Lidocaine 2. This study aimed to compare the antinociceptive effects of tramadol 5% and lidocaine 2% on mental nerve block in horses of the Brazilian Pony breed. Eight adult non-pregnant mares were used in this study. The ponies were tranquilized with acepromazine (5 µg kg, IV), and the infiltration of the mental foramen was performed in Treatment 1- tramadol 5% (T, 150 mg) or Treatment 2- lidocaine 2% (L, 60 mg), both at a total dose of 3 ml in each foramen. Heart rate (HR), respiratory rate (RR), systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP), rectal te...
Risk of anesthesia-related complications in draft horses: a retrospective, single-center analysis. To report anesthetic-related complications and determine risks associated with anesthesia in draft horses. Methods: Retrospective study. Methods: A 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. Methods: Demographics, 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 ...
The optimal PEEP after alveolar recruitment maneuver assessed by electrical impedance tomography in healthy horses. Electrical impedance tomography (EIT) has been an essential tool for assessing pulmonary ventilation in several situations, such as the alveolar recruitment maneuver (ARM) in PEEP titration to maintain the lungs open after atelectasis reversion. In the same way as in humans and dogs, in horses, this tool has been widely used to assess pulmonary aeration undergoing anesthesia, mechanical ventilation, recruitment maneuver, standing horses, or specific procedures. Unassigned: The present study aimed to evaluate the distribution of regional ventilation during ARM based on lung monitoring assessmen...
Laryngeal tie-forward in standing sedated horses. To investigate the feasibility and describe the clinical experience of performing laryngeal tie-forward (LTF) in standing horses unaffected (experimental) and affected (clinical) by intermittent dorsal displacement of the soft palate (iDDSP). Methods: Experimental study and case series. Methods: Five normal experimental controls and five client owned horses affected by iDDSP. Methods: Standing LTF was performed and evaluated in five experimental horses and five clinical cases diagnosed with iDDSP. Standing LTF was performed under endoscopic guidance with horses sedated and the surgical site de...
Intratesticular Versus Intrafunicular Lidocaine to Reduce Perioperative Nociception and Immunological Response in Ponies Undergoing Field Castration. The aim of this study was to evaluate the impact of intratesticular or intrafunicular lidocaine to reduce perioperative nociception and cytokine release in ponies undergoing field castration under total intravenous anaesthesia. Before castration, one group was injected with intrafunicular (FL) lidocaine and the other received intratesticular (TL) lidocaine. All ponies were premedicated with acepromazine (0.05 mg/kg) intramuscularly. Twenty minutes after the administration of acepromazine, xylazine (1 mg/kg) and butorphanol (0.02 mg/kg) were administered intravenously. Lidocaine 2% was given 1 ...
Variations in the application of equine prosthetic laryngoplasty: A survey of 128 equine surgeons. To document variations in the application of equine prosthetic laryngoplasty among equine surgeons. Methods: Cross-sectional survey. Methods: Six hundred and seventy-eight equine surgeons performing prosthetic laryngoplasty. Methods: An online questionnaire was sent to equine surgeons, including diplomates of the American College of Veterinary Surgeons and European College of Veterinary Surgeons. Questions focused on participant profile, surgical technique, antimicrobial therapy, and concurrent procedures. Descriptive statistical analysis was performed on the survey output. Results: Complete r...
Computed tomographic evaluation of the distal limb in the standing sedated horse: Technique, imaging diagnoses, feasibility, and artifacts. In several veterinary institutions, adjustments of CT machines have been made that allow for imaging of the standing horse. The risk of general anesthesia is eliminated and the shorter scan completion time reduces cost to clients. The objective of this retrospective, analytical study was to evaluate the technique, imaging diagnoses, feasibility, and image artifacts of multi-slice helical CT of horses' distal limbs acquired under standing sedation. The CT images of 250 horses of various breeds, aged 3-23 years, that underwent standing distal limb CT were evaluated. Three observers assessed the ...
The concentration of lidocaine and mepivacaine measured in synovial fluid of different joints of horses after single intra-articular injection. To determine the synovial fluid (SF) concentrations of lidocaine and mepivacaine after intra-articular injection with clinically relevant doses to the distal interphalangeal (DIP), metacarpophalangeal (MCP), middle carpal (MC), and tarsocrural (TC) joint at two different time points after injection in order to be able to compare concentrations with previously established concentrations associated with cytotoxicity and antimicrobial activity. Unassigned: In the first of two experiments, 20 joints (5 MC, 5 MCP, 10 DIP joints) of five horses under general anesthesia were injected with clinically ...
Methods Used for Endotracheal Tube Cuff Inflation and Pressure Verification in Veterinary Medicine: A Questionnaire on Current Practice. Endotracheal intubation is a routine procedure in veterinary anaesthesia, yet no consensus guidelines exist for endotracheal tube (ETT) cuff inflation and pressure measurement. The aim of this study was to assess current practice of ETT cuff inflation and seal verification in veterinary medicine. An online questionnaire was distributed among veterinary professionals who administer anaesthesia, comprising six demographic and twelve ETT cuff-related questions per species. N = 348 questionnaires were completed. Cuff pressure was measured by 30% of respondents in cats, 32% in dogs and 9% in both f...
Interventions for treatment of cutaneous melanoma in horses: a structured literature review. Several therapies have been developed to treat equine cutaneous melanoma, but formal comparisons among different treatment options are currently unavailable. It was our intent to assess the efficacy of different treatment protocols and the quality of the studies based on the original published data, and summarize the knowledge concerning the outcome after equine cutaneous melanoma management. This structured review followed PRISMA procedure to search for treatment protocols on equine cutaneous melanoma published from 1960 until June 2021. Studies were assessed for the risk of bias. A descripti...
Caudal epidural catheterization for pain management in 48 hospitalized horses: A descriptive study of demographics, complications, and outcomes. The placement of caudal epidural catheters in horses has become more frequent as a multi-modal analgesic strategy. Despite its integration into clinical practice, there are limited reports describing the use of caudal epidural catheterization for prolonged use in horses. The purpose of this study was to characterize the hospitalized caseload undergoing epidural catheterization for long-term epidural analgesic administration, to report the response to epidural therapy and observed complications, and to describe patient outcomes. Medical records of hospitalized equine patients that underwent pla...
Ultrasound-guided injection technique of the equine cervical nerve roots. Radiculopathy in horses is often a diagnosis of exclusion because of the non-specific clinical signs related to neck pain and possible forelimb lameness. There are no reported treatment options in the equine veterinary literature. The purpose of the study was to describe an ultrasound-guided injection of the cervical nerve root C3 to C8, to evaluate accuracy, time and safety and to anticipate possible complications on clinical cases. Under general anesthesia and with ultrasound guidance, five horses were injected from C3 to C8 with 1.5mL mix of contrast and latex. Immediately after euthanasia,...
Potassium penicillin and gentamicin pharmacokinetics in healthy conscious and anesthetized horses. To determine the effects of general anesthesia on the safety and efficacy of co-administered potassium penicillin G (PEN) and gentamicin (GENT) in horses. Methods: Nonrandomized crossover. Methods: Six adult, Thoroughbred horses. Methods: Horses were administered PEN (22 000 IU/kg IV) and GENT (6.6 mg/kg IV). Plasma samples were collected over a 6 h period and synovial fluid was collected at 30 min and 6 h respectively. Drug administration and sample collection protocols were repeated after at least a 48 hour washout period and induction of anesthesia using xylazine/ketamine and main...