Effect of ephedrine and phenylephrine on cardiopulmonary parameters in horses undergoing elective surgery

ObjectiveTo assess the cardiopulmonary effects of ephedrine and phenylephrine for management of isoflurane‐induced hypotension in horses.Study designProspective randomized clinical study.AnimalsFourteen isoflurane‐anesthetized horses undergoing digital palmar neurectomy.MethodsEphedrine (EPH group; 0.02 mg kg^?1 minute^?1; n = 7) or phenylephrine (PHE group; 0.002 mg kg^?1 minute^?1; n = 7) was administered to all horses when mean arterial pressure (MAP) was <60 mmHg. The infusions were ended when the target MAP was achieved, corresponding to a 50% increase over the pre‐infusion MAP (baseline). The horses were instrumented with an arterial catheter to measure blood pressure and allow the collection of blood for pH and blood‐gas analysis and a Swan‐Ganz catheter for measurement of cardiac output using thermodilution. Cardiopulmonary parameters were recorded at baseline and at 5, 30, 60 and 90 minutes after achieving the target MAP.ResultsIn both groups, the MAP and systemic vascular resistance (SVR) increased significantly at 5, 30, 60 and 90 minutes post infusion compared to baseline (p < 0.05). The EPH group had a significant increase in cardiac index (CI) and systemic oxygen delivery index at 5, 30, 60 and 90 minutes post infusion compared to baseline (p < 0.05) and compared to the PHE group (p < 0.05). The PHE group had significantly higher SVR and no decrease in oxygen extraction compared with the EPH group at 30, 60 and 90 minutes post infusion (p < 0.05). No significant differences in ventilatory parameters were observed between groups after the infusion.ConclusionsEphedrine increased the MAP by increasing CI and SVR. Phenylephrine increased MAP by increasing SVR but cardiac index decreased. Ephedrine resulted in better tissue oxygenation than phenylephrine.Clinical relevanceEphedrine would be preferable to phenylephrine to treat isoflurane‐induced hypotension in horses since it increases blood flow and pressure.     

Globin composition and synthesis of hemoglobins in developing fetal mice erythroid cells

Fetal mouse erythropoiesis proceeds initially in yolk-sac blood islands (8 to 12 days) and, subsequently, in liver (12 to at least 16 days). Yolksac cells synthesize three hemoglobins, Hb E(I), Hb E(II) and Hb E(III). Hb E(I) has x- and y-globin chains; Hb E(II) has alpha and y; HB E(III), alpha and z. No detectable beta-globin is formed in these cells. Liver erythroid cells form only adult hemoglobin, composed of alpha- and beta-chains.     

A new brachial plexus block technique in dogs

Objective To evaluate the feasibility and efficacy of a new technique of brachial plexus anesthesia in dogs. Study design Prospective, experimental study. Animals Twelve adult mongrel dogs, six males and six females weighing 14.8 ± 1.75 kg. Methods The animals were sedated with acepromazine 0.05 mg kg^?1 and anesthetized with propofol (6 mg kg^?1, IV bolus) followed by an infusion of 212 µg kg^?1 minute^?1. The brachial plexus block technique was performed utilizing the brachial artery as an anatomic landmark, the needle was inserted from the axilla and a nerve stimulator was used to ensure the accuracy of needle placement. Bupivacaine (0.375% with 5 µg mL^?1 epinephrine) was used at a dose rate of 4 mg kg^?1. Dogs underwent mid‐diaphyseal osteotomies of the humerus followed by intramedullary pin fixation. Results Onset time to motor and sensory block were 9.70 ± 5.52 and 26.20 ± 8.86 minutes, respectively. Analgesia lasted for 11.11 ± 0.47 hours. The block was effective in 91.6% of the animals, being verified by anesthesia of the whole front limb distal to the shoulder. One animal became hypotensive after the block and did not undergo the surgery at that time. In the remaining 10 animals the heart and respiratory rates, blood pressure, blood gas parameters and plasma bicarbonate concentration did not show any statistically significant alterations during the surgical procedure. Conclusions This brachial plexus block technique is effective in most cases to provide surgical analgesia for the front limb distal to the shoulder. Clinical Relevance Various surgical procedures in the front limb can be performed with a regional anesthetic technique without the use and concomitant risks of general anesthesia in dogs. Long‐lasting analgesia associated with this technique may also provide a valuable tool for the management of pain in the forelimb.     

A combination of methotrimeprazine, midazolam and guaiphenesin, with and without ketamine, in an anaesthetic procedure for horses.

A combination of 0.5 mg/kg of methotrimeprazine, 0.1 mg/kg of midazolam and 100 mg/kg of a 10 per cent guaiphenesin solution was investigated for the induction of recumbency in 15 horses; the addition of 1.6 mg/kg of ketamine was also evaluated in 15 horses and anaesthesia was maintained with halothane in oxygen. The horses became recumbent quickly and smoothly and they recovered quietly, with little ataxia. Tachycardia occurred after induction, but no other changes from pre-operative values were observed until halothane in oxygen had been given, when hypothermia, hypotension, bradypnoea, hyperoxaemia, respiratory acidosis and decreased respiratory minute volume developed. Horses given ketamine in addition to methotrimeprazine, midazolam and guaiphenesin were easier to intubate and recovered more quickly than horses receiving only methotrimeprazine, midazolam and guaiphenesin.     

Short-Term Effects of Duodenocecostomy on Body Weight,Glucose Absorption,Serum Components,and Intestinal Histopathology in Four Normal Horses

The objective of this study was to evaluate duodenocecostomy in horses performed through a ventral midline laparotomy and report its influence on body weight, glucose absorption, serum components, and characteristics of jejunum, cecum, and large colon histology. Four horses were submitted to the duodenocecostomy technique through a ventral midline laparotomy with animals in dorsal recumbency under inhalation anesthesia, followed by abdominal exploration. A side-to-side anastomosis was performed between the duodenojejunal flexure and the base of the cecum with two simple continuous suture lines of the serosal and muscular layers. The size of the opening created was approximately 2 cm in diameter. The mucosa layer was not sutured. After 30 days, animals were submitted to a second laparotomy to check the patency of the duodenocaecal fistula. During both laparotomy procedures, excisional biopsies of different segments of the gastrointestinal tract were performed. Information on physical examination findings, results of hematologic and histopathologic evaluations, and oral glucose absorption test were recorded. The horses did not have significant weight loss from baseline, and absorption curve of glucose did not significantly vary from baseline. Only triglycerides had significant alterations. Histologic evaluation of jejunum, cecum, and large colon did not show alterations of intestinal structure and morphology. We concluded that the proposed technique, principally in relation to the fistula size and not suturing the mucosa layer, allowed partial or total occlusion of the fistulae without the necessity of a second surgery and avoided the permanent bypass of ingesta and weight loss.     

Effects of two preanesthetic regimens for ophthalmic surgery on intraocular pressure and cardiovascular measurements in dogs

The effects of different preanesthetic medications (acepromazine plus either meperidine or butorphanol) given before the induction of anesthesia with midazolam and ketamine on intraocular pressure, heart rate, and arterial blood pressure were investigated in 20 dogs. Following administration of preanesthetics and induction of anesthesia, dogs were intubated and anesthesia was maintained with halothane for 10 minutes. Intraocular pressure was significantly higher (P <.05) at several evaluations for dogs premedicated with acepromazine/meperidine than for those premedicated with acepromazine/butorphanol. Mean heart rate and diastolic arterial blood pressure were significantly (P <.05) higher 5 minutes after administration of acepromazine/meperidine than after acepromazine/butorphanol. Results of this study suggest that acepromazine/butorphanol is a satisfactory preanesthetic combination to use before induction of anesthesia with midazolam and ketamine for ophthalmic surgery in dogs.     

Effects of l-Ascorbic Acid, α-Tocopherol and Co-culture on In Vitro Developmental Potential of Porcine Cumulus Cells Free Oocytes

The maturation and developmental potential on cumulus-cell-free oocytes is of great importance theoretically and practically. The present study was to investigate the effects of l -ascorbic acid, α-tocopherol and co-culture on in vitro developmental potential of porcine denuded oocytes (DOs). Porcine DOs were cultured in maturation medium supplemented with vitamin C (0, 50, 100, 250, 500, 750 μM) and vitamin E (0, 10, 20, 50, 100, 250 μ m ), respectively. And they were also co-cultured with dispersed cumulus cells (group CCscoculture), intact cumulus cells oocyte complexes (COCs) (group COCscoculture), and COCs whose oocytes were removed (group OOXcoculture), respectively. After 44 h incubation, the maturation rates, cleavage rates and blastocyst rates after parthenogenetic activation in three experiments mentioned above were collected and analysed, respectively. L -Ascorbic acid promoted porcine DOs in vitro maturation and blastocyt development after parthenogenetic activation while α-tocopherol did not increase the in vitro maturation rates, but improved the blastocyst rate. None of the three co-culture manner promoted the in vitro maturation and the cleavage of porcine DOs after parthenogenetic activation, but all the co-culture manners improved the blastocyst rates. Both Vitamin C and E enhance the in vitro developmental potential of porcine DOs. Co-culture increases the developmental potential of porcine DOs.     

Comparison of epidural and systemic tramadol for analgesia following ovariohysterectomy

The objective of the study was to compare epidural and systemic tramadol for postoperative analgesia in bitches undergoing ovariohysterectomy. Twenty animals, randomly divided into two groups, received either epidural (EPI) or intramuscular (IM) tramadol (2 mg/kg) 30 min before anesthetic induction. Analgesia, sedation, cardiorespiratory parameters, end-tidal isoflurane, blood catecholamines and cortisol, and arterial blood gases were measured at different time points up to 24 hr after agent administration. There were no differences between the two groups regarding cardiorespiratory parameters, end-tidal isoflurane, and pain scores. Two dogs in the IM and one in the EPI group required supplemental analgesia. Cortisol was increased (P<0.05) at 120 min (3.59 μg/dL and 3.27μg/dL in the IM and EPI groups, respectively) and 240 min (2.45 μg/dL and 2.54μg/dL in the IM and EPI groups, respectively) compared to baseline. Norepinephrine was also increased (P<0.05) at 120 min in both groups compared to baseline values. Epinephrine values were higher (P<0.05) in the IM group compared with the EPI group at 50 min, 120 min, and 1,440 min after tramadol administration. Epidural tramadol is a safe analgesic, but does not appear to have improved analgesic effects compared with IM administration.