Pharmacokinetics and effects of alfaxalone after intravenous and intramuscular administration to cats.

AIMS: To determine the pharmacokinetics, and anaesthetic and sedative effects of alfaxalone after I/V and I/M administration to cats. METHODS: Six European shorthair cats, three males and three females, with a mean weight of 4.21 (SD 0.53) kg and aged 3.8 (SD 0.9) years were enrolled in this crossover, two-treatment, two-period study. Alfaxalone at a dose of 5 mg/kg was administered either I/V or I/M. Blood samples were collected between 2-480 minutes after drug administration and analysed for concentrations of alfaxalone by HPLC. The plasma concentration-time curves were analysed by non-compartmental analysis. Sedation scores were evaluated between 5-120 minutes after drug administration using a numerical rating scale (from 0-18). Intervals from drug administration to sit, sternal and lateral recumbency during the induction phase, and to head-lift, sternal recumbency and standing position during recovery were recorded. RESULTS: The mean half-life and mean residence time of alfaxalone were longer after I/M (1.28 (SD 0.21) and 2.09 (SD 0.36) hours, respectively) than after I/V (0.49 (SD 0.07) and 0.66 (SD 0.16) hours, respectively) administration (p<0.05). Bioavailability after I/M injection of alfaxalone was 94.7 (SD 19.8)%. The mean intervals to sternal and lateral recumbency were longer in the I/M (3.73 (SD 1.99) and 6.12 (SD 0.90) minutes, respectively) compared to I/V (0 minutes for all animals) treated cats (p<0.01). Sedation scores indicative of general anaesthesia (scores >15) were recorded from 5-15 minutes after I/V administration and deep sedation (scores 11-15) at 20 and 30 minutes. Deep sedation was observed from 10-45 minutes after I/M administration. One cat from each group showed hyperkinesia during recovery, and the remainder had an uneventful recovery. CONCLUSIONS AND CLINICAL RELEVANCE: Alfaxalone administered I/V in cats provides rapid and smooth induction of anaesthesia. After I/M administration, a longer exposure to the drug and an extended half life were obtained compared to I/V administration. Therefore I/M administration of alfaxalone could be a reliable, suitable and easy route in cats, taking into account that alfaxalone has a slower onset of sedation than when given I/V and achieves deep sedation rather than general anaesthesia.

Mechanical ventilation of six dogs anaesthetised with isoflurane or sevoflurane delivered by a Komesaroff anaesthetic machine.

After intravenous induction, six beagles were connected to a Komesaroff machine provided with a single in-circuit vaporiser and ventilated mechanically at either nine or 14 breaths/minute while anaesthetised with either isoflurane or sevoflurane. The vaporiser was initially set at position 4/4 (fully open) and the anaesthetic concentrations were measured after one and five minutes; the vaporiser was then set at the lowest setting able to maintain anaesthesia. Cardiorespiratory variables were measured throughout the study. In most cases anaesthesia was maintained at setting 1/4 with isoflurane and at setting 1.5/4 or 2/4 with sevoflurane.

Sedative and cardiorespiratory effects of three doses of romifidine in comparison with medetomidine in five cats.

This study was designed to compare the effects of three doses of romifidine (200, 400 and 600 microg/kg) with medetomidine (80 microg/kg) administered intramuscularly to five cats. The quality of sedation and the cardiovascular and respiratory effects of each treatment were evaluated, and the onset and duration of the sedation, and the cats' recovery times, were measured. Cardiorespiratory variables were also analysed. The dose of 200 microg/kg romifidine was clinically superior to the other doses of romifidine, providing moderate sedation, with minor cardiorespiratory and other adverse effects. However none of the doses of romifidine induced as deep and reliable sedation as the dose of medetomidine.

Agonistas alfa-2 adrenérgicos en sedación y anestesia veterinaria / Alpha-2 adrenoceptor agonists for sedation and veterinary anaesthesia

Los sedantes se usan ampliamente en veterinaria para inmovilizar químicamente a los pacientes de caraa efectuar procedimientos poco cruentos. Estos fármacos también son administrados de forma rutinaria en lapreanestesia, ya que resultan benefi ciosos para el desarrollo de la anestesia general. Los agonistas alfa-2 han adquiridouna especial relevancia debido a sus efectos sedantes, analgésicos y anticonvulsivantes. Estos sedantesproducen alteraciones en el sistema cardiovascular, tales como hipertensión/hipotensión, bloqueos auriculoventricularesy bradicardia, que deben considerarse antes de su administración. Existen antagonistas selectivosque revierten rápidamente las acciones producidas por los mismos

Sedative drugs are widely used in veterinary practice to chemically restrain patients undergoing minor andnon invasive procedures. These drugs are also routinely administered for pre-anaesthesia due to its positiveeffects on the outcome of the general anaesthesia. The alpha-2 agonists are most important within these group ofdrugs due to its profound and reliable sedative properties as well as its good analgesic and muscle relaxantproperties. Nevertheless, the alpha-2 agonist drugs also exhibit unwanted effects such as hyper/hypotension,second degree auriculo-ventricular blocks and bradychardia. Selective alpha-2 antagonist drugs are now marketedto reverse these adverse effects as well as to accelerate the recovery after using these drugs

Comparison of the analgesic effects of meloxicam and carprofen administered preoperatively to dogs undergoing orthopaedic surgery.

Thirty-two dogs undergoing operations to repair a torn cranial cruciate ligament or a fractured long bone were randomly allocated to one of two treatment groups in a study on postoperative pain. Sixteen of the dogs were given 4 mg/kg carprofen and the other 16 were given 0.2 mg/kg meloxicam subcutaneously before the operation. The signs of pain shown by the animals were assessed for 24 hours on a visual analogue scale, a discontinuous scoring system, and a score based on five behavioural and physiological variables. The dogs' heart and respiratory rates and their mean arterial blood pressures were also measured non-invasively at each assessment. Blood samples were taken before the surgery and 24 hours after it, and the concentrations of urea and creatinine were measured in plasma. Both drugs were effective in relieving the signs of pain for up to 24 hours in all the dogs. There were no significant changes in the concentrations of urea and creatinine, and no adverse effects were reported during the postoperative period.

Acupunto Renzhong en el caballo. Estudio anatómico e histológico / Acupoint renzhong (jenchung GV-26) in the horse. Anatomical and histological study

El propósito de este estudio es documentar las características histológicas y anatómicas del acupunto Renzhong GV-26 en diez caballos de raza española. Primero, se midió la resistencia eléctrica para la localización del acupunto, y posteriormente se insertó una aguja de acupuntura a una profundidad de 1 cm dentro del acupunto. Luego se obtuvieron muestras del acupunto y fueron procesadas por técnicas histológicas de rutina. Los resultados muestran que el acupunto Renzhong GV-26 está situado en el estrato intermedio del labio superior, representado por diferentes estructuras, como tejido conectivo denso, músculo estriado esquelético, fibras nerviosas y estructuras vasculares. Es decir, numerosas estructuras conforman el acupunto Renzhong GV-26 en el caballo (AU)

The purpose of this study was to document the anatomic and histologic characteristics of acupoint Renzhong GV-26 in ten Spanish horses. First, the electrical skin resistance was measured to locate the acupoint, and the needles were inserted to a depth of 1cm into the acupoint. Then, the tissue surrounding the acupoint was removed, sectioned serially, and processed by routine histologic techniques. The results show that the acupoint Renzhong GV-26 is situated in the intermediate area of the upper lip, represented by several structures of dense connective tissue, skeletal muscle tissue, nerve fibers and vascular structures. Therefore, numerous structures conform part of the acupoint Renzhong GV-26 in the horse (AU)

Left perinephric abscess associated with nephrolithiasis and bladder calculi in a bitch.

An eight-year-old, entire female Pekingese cross, weighing 3.8 kg, had been inappetent with fever, depression, abdominal pain, vomiting and diarrhoea for seven days. The radiographic and ultrasonographic findings were consistent with glomerulonephritis, nephrolithiasis in both kidneys, bladder calculi and an accumulation of fluid in the left perinephric space. The clinical signs, together with the results of the diagnostic imaging, suggested that this fluid could be pus. A definitive diagnosis of a subcapsular abscess in the left kidney was established when this kidney was removed surgically. A histopathological examination of the kidney revealed a diffuse suppurative interstitial nephritis, membranous glomerulonephritis and an abscess invading the perinephric adipose tissue from the renal cortex. Twelve months after surgery the dog remains clinically stable, but owing to the disease of its remaining kidney its long-term prognosis is poor.

Clinical and radiographic study of bone and joint lesions in 26 dogs with leishmaniasis.

Twenty-six dogs with parasitologically confirmed leishmaniasis and abnormalities of gait were studied to determine the most common radiological patterns of bone and joint lesions. The clinical findings included either lameness, joint pain and crepitation, soft tissue swelling and/or muscle atrophy. Bone lesions were observed radiographically in 12 of the 26 dogs; the radius and ulna were affected in seven, the tibia in six and the femur in six. Joint lesions were observed radiographically in 15 of the 26 dogs; the carpus and stifle were affected in all 15, and the tarsus in nine. There was a tendency for the bones and joints to be affected bilaterally. The radiographic patterns observed were different in the long bones and the joints. In the long bones, the most common pattern was periosteal and intramedullary proliferation, involving the diaphyses and related to the nutrient foramen; in the joints, two patterns, either non-erosive or erosive polyarthritis with soft-tissue swelling, were observed. The changes observed in the synovial fluid were associated in most cases with osteolytic lesions. However, Leishmania organisms were identified in the synovial fluid from joints without bony radiographic changes.

Evaluation of a mammography film-screen combination to take bone radiographs in small animals

Se han estudiado los factores de exposición y la calidad de las imágenes de radiografías del sistema óseo en 5 gatos con peso medio de 3.8 Kg. y 5 perros con un peso medio de 16.8 Kg. Para ello se han empleado dos combinaciones de película-pantalla, uno convencional ortocromático fine de tierras raras y otro de mamografía, utilizando un aparato de rayos X estándar. El estudio refleja que la combinación película-pantalla de mamografía es superior al sistema convencional ortocromático fine en resolución y contraste, para obtener radiografías del sistema óseo de zonas con poco grosor y escasa masa muscular en pequeños animales. Además, los factores de exposición requeridos para obtener radiografías con esta técnica, son similares a los necesarios para el sistema convencional. (AU)

Unilateral renal agenesis associated with additional congenital abnormalities of the urinary tract in a Pekingese bitch.

An eight-month-old Pekingese bitch with urinary incontinence was found to have three congenital anomalies of the urinary tract: left renal agenesis, bilateral ectopic ureters with a left cranial blind-ending ureter, and urinary bladder hypoplasia. The diagnoses were made by retrograde vaginourethrography, excretory urography, ultrasonography and duplex Doppler ultrasonography. Although urological anomalies associated with renal agenesis have been frequently observed, a cranial blind-end ectopic ureter has not, to the authors' knowledge, been described in the bitch. The dog was managed medically with a restricted protein diet because of a compromised unilateral kidney with hydronephrosis and hydroureter.

Estudio comparativo de dos regímenes de preanestesia: acepromacina/petidina y medetomidina sobre la anestesia con Ketamina o alfaxalona/Alfadolona en el gato / Comparative study of two preanaesthetic protocols: acepromacine/petidine and medetomidine before ketamine or alfaxolone/alfadolone anaesthesia in the cat

Se estudian cuatro protocolos de anestesia inyectable Acp (0,1mg/kg) - Pet (3,3mg/kg) - Ket (10mg/kg), Med (80 microg/Kg) - Ket (5mg/kg), Acp (0,1mg/kg) - Pet (3.3mg/kg) - Saf (10mg/kg) y Med (80 microg/kg) - Saf (5mg/Kg) en cinco gatos. La preanestesia fue administrada vía intramuscular. Posteriormente, se administró endovenosamente el anestésico general. Se intubó a los animales y se valoró la calidad y tiempo de intubación. Para cada protocolo, se determinó la duración y calidad de la anestesia, registrando diversas constantes vitales (FR, FEFCO2, SpO2, FC, ECG, PAS y temperatura rectal) cada 5 min. La combinación preanestésica Acp-Pet no indujo sedación adecuada y su uso con ketamina aportó una anestesia superficial. La combinación Acp-Pet-Saf produjo anestesia de calidad moderada e hipotensión. La medetomidina produjo profunda sedación y un buen plano anestésico tras la administración de ketamina y Saffan®. (AU)

A rating system for prompt clinical diagnosis of ischemic stroke.

BACKGROUND: When a CT scan is not available, an early accurate clinical diagnosis of ischemic stroke is essential to initiate prompt therapy. Our objective was to construct a clinical index that is easy to use when stroke patients are first evaluated at the hospital, to identify those who probably are experiencing an acute ischemic episode. The study was conducted at a university-affiliated medical referral center and two community general hospitals in Mexico. METHODS: Clinical records were reviewed for 801 patients with sudden onset of a focal or global neurologic dysfunction, presumably of vascular origin lasting more than 24 h. Eligibility criteria for this study were admission to the hospital within the first 24 h after symptomatic onset, CT scan diagnosis between 24 and 72 h, and age >45 years. Ischemic stroke included cases of arterial brain infarction, while nonischemic stroke included subarachnoid or intraparenchymatous hemorrhage, mass lesion, venous infarction, and in cases without a CT scan evidence that could explain the clinical manifestations. Data excerpted for analysis were age, sex, history of diabetes mellitus or previous stroke/transient ischemic attack (TIA), time of onset of symptoms, presence of headache, vomiting, neck stiffness, hemiplegia, leukocytosis or atrial fibrillation, diastolic blood pressure, and Glasgow coma scale (GCS) rating. Two multivariable analyses were used: 1) step-wise multiple logistic regression (SMLR), and 2) conjunctive consolidation (CC). RESULTS: After appropriate exclusions, the study proceeded with 83 ischemic and 42 nonischemic stroke patients. With SMLR, six variables were selected as predictive for ischemic stroke, including neck stiffness, diastolic blood pressure, previous history of stroke/TIA, hemiplegia, GCS, and atrial fibrillation. An appropriate sum of weighted ratings had a positive predictive value (PPV) of 100% for ischemic stroke. With consolidated categories, the PPV was 97% when patients had the following: no neck stiffness; no atrial fibrillation but history of stroke/TIA and GCS > or =12, or no neck stiffness but atrial fibrillation. CONCLUSIONS: Among patients with acute stroke, clinical data can be used to identify a group with a high probability of ischemic stroke. There are slightly different results between both methods; while SMLR includes the four variables selected by CC, the latter included neither diastolic blood pressure nor hemiplegia/hemiparesia. However, CC results seem easier to understand and interpret than with SMLR.

Comparison of different doses of iohexol with amidotrizoate for excretory urography in cats.

In five cats with normal renal function, doses of 200, 400, 600 and 800 mg iodine kg(-1)bodyweight of iohexol (350 mg iodine ml(-1)) were assessed in comparison to a dose of 880 mg iodine kg(-1)bodyweight of meglumine-sodium amidotrizoate (370 mg iodine ml(-1)) to determine the smallest dose which produces diagnostically adequate results for excretory urography. Urographic quality, haematologic and biochemical parameters, urinalysis and urinary osmolality, pulse and respiratory rates, blood pressure and adverse effects were determined. Iohexol presented fewer adverse reactions and influenced blood pressure less than amidotrizoate. The smallest dose of iohexol which provided urograms of similar quality to amidotrizoate was 400 mg iodine kg(-1)bodyweight. This study suggests that iohexol is safer and produces urograms of better quality than amidotrizoate.

Efficacy of the Komesaroff anaesthetic machine for delivering isoflurane to dogs.

The Komesaroff machine is a low-flow, closed-circle circuit with a low resistance vaporiser, of the Goldman type, in circuit. This trial assessed the mechanical consistency of the delivery of isoflurane by the vaporisers, and used six dogs to compare the in vivo cardiorespiratory effects of the anaesthetic agent delivered by the Komesaroff machine with the effects of a circle system with high flows in the semi-closed mode. The delivery of isoflurane was constant for each vaporiser setting and no potentially dangerous concentrations of isoflurane were observed. The mean (sem) percentages of isoflurane were 0.18 (0.019) at setting I, 1.46 (0.055) at setting II, 3.12 (0.066) at setting III and 3.01 (0.047) at setting IV. There were no significant differences between the two types of circuit in vivo, and the measured haemodynamic variables were satisfactory throughout the experiments.

Comparative study of air coagulation, fibrin sealant, and suture in experimental liver injury.

OBJECTIVE: To test the effects of hot air coagulation, fibrin sealant, and horizontal mattress sutures on haemostasis and regeneration in experimental hepatectomy. DESIGN: Randomised laboratory experiment. SETTING: Teaching hospital, Spain. MATERIAL: 200 rats divided into four groups (three experimental [n=60 in each] and one control [n=20]). INTERVENTIONS: Hepatic injuries were repaired by suture, coagulation, or fibrin sealant in the three experimental groups. The control group was used only to supply baseline blood samples. 10 animals in each experimental group were killed at 3, 5, 10, 25, 40, and 60 days. MAIN OUTCOME MEASURES: Time taken to achieve haemostasis, and histopathological scores of healing. RESULTS: Mattress sutures took mean (SEM) of 346 (7) seconds to control the haemorrhage and allow the liver to regain its shape and 4 rats developed abscesses (7%). Fibrin sealant achieved haemostasis immediately and the liver regained its shape in 58 (2) seconds; 2 rats (3%) developed abscesses. Hot air coagulation achieved haemostasis in 27 (1) seconds and there were no abscesses. CONCLUSION: Fibrin sealant was the best technique because it achieved immediate haemostasis and speedy regeneration. However, hot air coagulation is a useful and cheaper alternative.

Predictive value of signs and symptoms in the diagnosis of subarachnoid hemorrhage among stroke patients.

Clinical diagnosis of subarachnoid hemorrhage (SAH) is frequently misdiagnosed with intracerebral hemorrhage (ICH) or cerebral infarction (CI), which delays appropriate referral. This study was undertaken to create a clinical index to select, among stroke patients, those with the highest probability of having a SAH. Clinical data of patients with acute stroke were evaluated with the X2 and the Fisher exact test; a p value < 0.05 was considered significant. Significant variables were included in a "log-lineal regression analysis" where those with an odds ratio (OR) 95% confidence limits not including the unit were considered to construct an index using the odds ratio coefficient (C). The results indicated that of 197 records which were included, 22 cases of SAH and 175 of ICH or CI were demonstrated. Kappa coefficients for observer variation in clinical data retrieval was 0.91. After "log-lineal regression analysis" was carried out the following variables were significant: neck stiffness (C = 3, OR = 21); lack of focal neurologic signs (C = 2, OR = 6.88); and age < or = 60 years (C = 1.5, OR = 4.35). A fourth variable, seizures (C = 1, OR = 3.25), was marginally significant (p = 0.07), but added predictive value to the index. The positive predictive values of the sum of the coefficients were: 0 = 0%; 1-2 = 3%; 2.5-3.5 = 21%; 4-5 = 40%; 6.5 = 75%; 7.5 = 100%. In conclusion, when a stroke patient shows neck stiffness, or any combination of young age, lack of focal neurologic signs or seizures (a score > or = 2.5, the index has a 91% sensitivity and 82% specificity), he/she must be referred to a tertiary care center.

Method of recording cerebrospinal fluid pressure at three anatomic places in conscious and unrestrained adult wistar rats.

There does not appear to be a consensus on the normal values of cerebrospinal fluid pressure (Pcsf) in rats because of the different conditions in which each experiment has been done. Anaesthesia, restraint or recordings from different anatomical places and the use of simultaneous infusions could produce a great variability in the obtained results and because of that the average Pcsf in rats has been reported to be between 2 and about 18.5 cm H2O. The aim of this study is to provide new information about the normal values of Pcsf in adult, conscious rats by carrying out long-term measurements, for 3 consecutive days, from different anatomical places. Thirty male Wistar rats divided in three experimental groups of ten animals each were used. A catheter of silicone was implanted into the lateral ventricles in group I, the cisterna magna in group II, and the lumbar subarachnoid space in group III to record the Pcsf values. This catheter was attached to a swivel system to allow unrestrained and free behaviour in the rats. Mean values of normal Pcsf values were 13.03 +/- 0.73 cm H2O from the lateral ventricles, 15.9 +/- 0.73 cm H2O from the cisterna magna, and 16.73 +/- 1.14 cm H2O from the lumbar subarachnoid space.

Local and systemic effects of water-soluble contrast media and barium in rats with chronic small bowel obstruction.

RATIONALE AND OBJECTIVES: The local effects on the small intestine and systemic changes produced by different contrast media in small bowel obstruction, with time courses of 4 days, were evaluated. MATERIALS AND METHODS: Four groups, each with 10 normal rats and another four groups (also each with 10 rats) that had ligation of the terminal ileum (obstructed rats) for 4 days were given 3 mL of barium, meglumine sodium diatrizoate, iohexol, or saline (control animals). Radiographs were taken immediately, 1 and 4 hours after administration of contrast media. Immediately before sacrifice, blood samples were taken to determine the hematocrit (Hct), hemoglobin (Hb), white blood cell count (WBC), red blood cell count (RBC), and serum sodium, and potassium and chloride concentrations. Specimens of small bowel were taken for histologic and morphometric analysis. RESULTS: In obstructed rats, the image quality with iohexol improved on final radiographs despite being diluted in the great intestinal contents. There was an improvement in the serum electrolyte concentrations in the obstructed animals that were given any one of the contrast media, the best improvement being in the iohexol groups. A shortening of the length of epithelial cells when any one of the contrast media was administered was observed, as was an increase in the lymphatic space area in the diatrizoate group in normal rats. In the bowel proximal to the obstruction, the lymphatic space area was increased in the diatrizoate group and the size of the epithelial cells was higher in the diatrizoate and iohexol groups compared to the barium and saline groups. CONCLUSION: Our results suggest that iohexol offers good radiologic efficacy and excellent systemic and local tolerance in small bowel obstruction.