General Anaesthesia In Horses Research Articles

Equine perioperative fatalities associated with general anaesthesia at a private practice – a retrospective case series

ObjectiveTo determine the fatality rate of horses undergoing general anaesthesia at a private equine referral practice using a limited number of anaesthetic protocols. MethodsA retrospective analysis of records (n = 17 961) from all horses undergoing general anaesthesia for surgical procedures from 1997 to 2001 at Rood and Riddle Equine Hospital, Lexington, Kentucky, USA. Results were reported as percentage of the population, and as crude mortality rates for each procedure (deaths per 1000). ResultsThe prevalence of equine fatalities directly related to anaesthesia was 0.12% (n = 21) and this rose to 0.24% (n = 42) with the inclusion of horses killed or dying within 7 days post general anaesthesia. Causes of death directly related to anaesthesia were cardiac arrest (n = 10), fracture in recovery stall (n = 8), neuropathy and myopathy necessitating euthanasia (n = 3). Crude mortality rates per procedure were ≤7 deaths per 1000 cases, except arthrodesis/osteotomy cases were 66.7 deaths per 1000 cases. ConclusionsThe anaesthetic fatality rate at this practice is lower than has been reported previously.Clinical relevance Familiarity with an anaesthetic protocol in combination with reduced anaesthetic time, emergencies of shorter duration between diagnosis and surgery, and adequate preoperative examination appear to minimize the risks associated with general anaesthesia in horses.

Isoflurane sparing and the influence on cardiovascular and pulmonary parameters through a continuous romifidine hydrochloride infusion during general anaesthesia in horses - a clinical study

Isoflurane sparing and the influence on cardiovascular and pulmonary parameters through a continuous romifidine hydrochloride infusion during general anaesthesia in horses - a clinical study

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

To report complications observed using a hydro-pool recovery system after general anesthesia in horses. Retrospective study. Sixty horses. Retrospective review of the medical records and quality of recovery from anesthesia of 60 horses that had surgical or diagnostic procedures under general anesthesia. 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. 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. A hydro-pool system is a useful method for recovering horses from general anesthesia when difficult recoveries are anticipated.

Urinary effects of xylazine and general anesthesia in horses

The purpose of this study was to characterize urine flow and biochemical parameters in horses given xylazine (XYL) and anesthetized with ketamine and isoflurane. Nine mares [9 ± 2 (mean ± SE) years; 492 ± 17 kg] were studied. They were anesthetized for 2 hours in support of a campus-approved, laboratory-based orthopedic study. The day prior to anesthesia, a venous blood sample was obtained for biochemical analysis from each unmedicated mare. The urinary bladder was catheterized and emptied, and urine collected over the next three hours to quantitate the pre-drug values. The next day the mares were similarly catheterized. After obtaining urine and venous blood samples, XYL (1.1 mg kg−1 IV) was administered. Anesthesia was induced 5 minutes later with ketamine (2.2 mg kg−1 IV) and diazepam (0.04 mg kg−1 IV) and maintained with isoflurane in O2. Lactated Ringer's solution (10 mL kg−1 hours−1) was administered IV and dobutamine infused as required to maintain mean arterial blood pressure between 70 and 80 mm Hg. Mechanical ventilation maintained PaCO2 between 48 and 52 mm Hg and PaO2 > 200 mm Hg. Blood and urine were collected at 30, 60, and 120 minutes during anesthesia, and at 1 hour postanesthesia. Data were analyzed with RM anova; with p < 0.05. Control urine flow was 0.92 ± 0.17 mL kg−1 hour−1. Urine flow was significantly increased at 30 and 60 minutes following XYL (2.14 ± 0.59 and 2.86 ± 0.97 mL kg−1 hour−1, respectively), but returned to control levels by the end of anesthesia. The most notable biochemical change was an initial significant increase in serum glucose from 121 ± 4 to 167 ± 8 mg dL−1 at 30 minutes post-XYL that was not accompanied by a significant glucosuria (control value 4 ± 1 mg dL−1). We conclude that urine output increases in anesthetized horses following XYL, but this increase is not as a result of glucosuria.

A retrospective study of mortality associated with general anaesthesia in horses: emergency procedures

A retrospective study evaluated 995 emergency equine general anaesthetics. The total mortality for emergency procedures was 31.4 per cent. This figure was examined in more detail to determine if all...

A retrospective study of mortality associated with general anaesthesia in horses: elective procedures

A retrospective analysis examined mortality associated with all procedures requiring general anaesthetic, performed at the Philip Leverhulme Large Animal Teaching Hospital, during the five-year period from February 1991 to December...

Evaluation of 25%, 50%, and 67% Nitrous Oxide with Halothane‐Oxygen for General Anesthesia in Horses

Twenty-five percent, 50%, and 67% nitrous oxide was administered to 12 horses anesthetized with halothane and oxygen. Compared to halothane-oxygen alone, there was no significant difference in heart rate, systolic, diastolic, or mean blood pressure values, arterial pH, PaCO2, or plasma bicarbonate values when nitrous oxide was included. A significant linear reduction in PaO2 values could be correlated with N2O:O2 concentrations. The halothane level required to maintain surgical anesthesia was reduced when nitrous oxide was administered, but it was not affected by changing the nitrous oxide concentrations. Nitrous oxide concentrations greater than 25% provide no additional reduction in halothane requirement and may be accompanied by PaO2 values that pose risk to the horse.

馬・牛（山羊）・豚の全身麻酔法

馬・牛（山羊）・豚の全身麻酔法

Domosedan in premedication and general anaesthesia in horses

Domosedan in premedication and general anaesthesia in horses

Observations on the use of glyceryl guaiacolate as an adjunct to general anaesthesia in horses.

Twenty-one horses undergoing clinical surgery and diagnostic procedures received 15% glyceryl guaiacolate followed by a rapid intravenous injection of a thiobarbiturate for induction of anaesthesia. Premedication was with atropine and acepromazine. Induction was smooth and free from problems apart from transient apnoea in some horses. Maintenance of anaesthesia was with oxygen and halothane administered by means of a closed circle system with soda-lime absorber and with the vaporiser out of circuit. During the period immediately following induction, the heart rate increased and the respiratory rate fell. Blood gas estimations were carried out on 6 horses during anaesthesia. These horses showed respiratory acidosis. Arterial blood oxygen tension values were above those reported in conscious horses. Use of glyceryl guaiacolate in this way provides a safe induction and enables transition to a stable maintenance period which is followed by a quiet and uneventful recovery.