Carlotta Lambertini

Transdermal spinal catheter placement in piglets: Description and validation of the technique.

BACKGROUND The swine species represents a perfect model for translational medicine due to its physiological and anatomical resemblance to humans. The development of techniques for spinal catheter insertion in swine is significantly useful but, at the moment, the only technique described requires laminectomy as a surgical approach. NEW METHOD The proposed techniques represent a transdermal approach for catheter placement in piglets. The study was divided into Phase I (anatomical study on 8 cadavers) and Phase II (in vivo application of the technique in 20 anaesthetised 30-day old piglets). A spinal needle was introduced between the L2 and L3 spinous processes with a ventro-cranial orientation until cerebro-spinal fluid leakage. It was then replaced with a Tuohy needle, used to introduce the catheter into the intrathecal space. Before inserting the catheter, the approximate length from the insertion point to the external projection of the Cisterna Magna was measured using the gradation markings on the device. RESULTS The technique described allowed spinal catheter placement in all piglets. In Phase I, the correct placement was confirmed using fluoroscopy while, in Phase II, cerebrospinal fluid leakage from the needle was relied on. No clinical alterations were detected either during the procedure or during the following days. COMPARISON WITH EXISTING METHOD This technique is easy and requires less skilled operators when compared to the other existing method which involves a surgical approach. Moreover, being less invasive, it potentially leads to fewer complications. CONCLUSIONS In conclusion, the technique can be performed safely in piglets, and provides an easier and less invasive approach for spinal catheter insertion.

Non-invasive evaluation of the haemodynamic effects of high-dose medetomidine in healthy cats for semen collection

Objectives This study aimed to assess non-invasively the cardiovascular effects of high-dose medetomidine on healthy male cats undergoing semen collection. Methods Haemodynamic evaluations were assessed on the basis of clinical examination, systolic arterial pressure (SAP) and transthoracic echocardiographic examination. Eight client owned, male domestic shorthair cats were sedated with a bolus of medetomidine intramuscularly (IM; 0.13 mg/kg), and semen collection was performed. A second transthoracic echocardiographic examination and SAP measurement were carried out 15 mins after sedation. At the end of the examination, the patients received a bolus of atipamezole (0.3 mg/kg) IM. Results The cats were deeply sedated, relaxed and laterally recumbent during the entire procedure. No rhythm abnormalities were observed during the examinations and no significant increase in SAP was recorded. Heart rate dropped from 200 ± 33 to 92 ± 13.1 beats per min after sedation. There was a significant increase in left ventricular dimensions and the left atrial area. The parameters of left ventricular systolic function were reduced, as were systemic and pulmonary cardiac outputs. Peak diastolic wave velocities were significantly reduced, while isovolumic contraction and relaxation time of the left ventricle were prolonged. Aortic valve insufficiency was recorded for all cats, while mitral valve insufficiency was noted in five cats. None of the subjects developed systolic anterior motion of the mitral valve. Conclusions and relevance The protocol allowed us to collect good semen samples in healthy cats. However, high-dose medetomidine induces significant haemodynamic effects on the feline heart, mainly due to a reduced heart rate, an increased cardiac preload and impaired systolic function. The animals recovered from the anaesthesia, after antagonist administration, without showing any clinically relevant consequences.

Comparison of intraperitoneal ropivacaine and bupivacaine for postoperative analgesia in dogs undergoing ovariohysterectomy

OBJECTIVE To compare postoperative analgesia following either intraperitoneal (IP) ropivacaine or bupivacaine in dogs undergoing ovariohysterectomy (OVH) in the scope of multimodal analgesia. STUDY DESIGN Prospective, randomized, blinded clinical study. ANIMALS A total of 45 privately owned dogs undergoing OVH, aged 37 ± 28 months and weighing 11.3 ± 4.5 kg. METHODS Dogs were premedicated with acepromazine (0.05 mg kg-1) and morphine (0.5 mg kg-1) intramuscularly (IM). Anaesthesia was induced with alfaxalone and maintained with isoflurane in oxygen. Carprofen (4 mg kg-1) was injected subcutaneously after intubation. Dogs were randomly assigned to receive either bupivacaine (group B; 3 mg kg-1) or ropivacaine (group R; 3 mg kg-1) IP prior to complete closure of the linea alba. At 0.5, 1, 2, 4, 6 and 8 hours after extubation, sedation and postoperative pain were assessed, using the short form of the Glasgow Composite Pain scale (GCPS-SF), a dynamic interactive visual analogue scale (DIVAS), and mechanical nociceptive threshold (MNT) measurement. Rescue morphine (0.2 mg kg-1) was administered in case of ≥ 5/20 or ≥ 6/24 in the GCPS-SF and/or >40 mm in the DIVAS. Parametric data were compared using the t test; nonparametric data were analysed with the two-sample Wilcoxon test (p < 0.05). RESULTS The GCPS-SF score was significantly higher in group R at 8 hours. There was no other significant difference regarding sedation or analgesia between the groups. Rescue analgesia was administered to 15 dogs (R: 9/22; B: 6/22), with no significant difference between the groups. MNT values decreased in both groups at all time points when compared to baseline. No adverse effects were observed. CONCLUSIONS AND CLINICAL RELEVANCE Ropivacaine or bupivacaine IP in combination with morphine IM and carprofen SC provided comparable postoperative analgesia in dogs after OVH for 6 hours. However, the anaesthetic protocol used did not prevent the administration of rescue analgesia in 41% of animals.

Cardiorespiratory effects of medetomidine and dexmedetomidine combined with tiletamine-zolazepam for the immobilization of Asiatic black bears (Ursus thibetanus) under isoflurane general anesthesia

The aim of this paper was to compare the cardiorespiratory effects of the two combinations (medetomidine-tiletamine-zolazepam (MTZ) or dexmedetomidine-tiletamine-zolazepam (DTZ)) used for Asiatic black bear (Ursus thibetanus) immobilization. A retrospective analysis was carried out, reviewing the anesthetic records of captive bears. Sixty-six records were reviewed. The bears were immobilized, and general anesthesia was maintained with isoflurane vaporized in 100% oxygen. The mean sedation time and score were evaluated. The cardiorespiratory parameters were recorded every 10 minutes from intubation until extubation. Mean sedation time was 26.1 ± 14.5 minutes for the MTZ group and 25.6 ± 19.4 minutes for the DTZ group. The heart rate and the respiratory rate were higher in the bears immobilized with DTZ (66 ± 19 beats/min; 13 ± 5.2 breaths/min) as compared with the bears immobilized with MTZ (57 ± 14.5 beats/min; 10 ± 4.7 breaths/min) whereas the mean arterial pressure did not differ significantly between the groups. The body temperature was in the normal range throughout the procedures in all bears (MTZ 36.3 ± 0.9°C; DTZ 37 ± 1°C). In conclusion, the two protocols used in this study have been proven to be safe and reliable for the immobilization of Asiatic black bears, and the DTZ combination seemed to be associated with less cardiorespiratory depression than the MTZ one.

Short-term general anaesthesia with tiletamine/zolazepam in horses sedated with medetomidine for castration under field conditions

ABSTRACT The objective of the study is to evaluate the anesthetic effect produced by the tiletamine/zolazepam association in horses sedated with medetomidine undergoing orchiectomy under field conditions. Ten uncastrated male horses, American Society of Anesthesiologists category I, undergoing orchiectomy, were enrolled in the study. The horses received acepromazine (0.03 mg kg−1 intramuscularly) 30 minutes before sedation with medetomidine (8 &mgr;g kg−1 intravenously). Anesthesia was induced with tiletamine/zolazepam (0.7 mg kg−1 intravenously). During anesthesia, heart rate (HR), pulse quality, respiratory rate, temperature, SpO2, movement, and reflexes were measured every 5 minutes. Arterial blood gases were evaluated before the premedication and during the surgical procedure. The quality of induction and recovery was recorded. The sedation was appropriate, and the quality of recovery was evaluated as good. A statistically significant difference was revealed between the basal and intra‐anesthesia HR. No differences were observed in blood gas parameters during the procedure. The results suggested that general anesthesia produced with tiletamine/zolazepam for induction in horses sedated with medetomidine is suitable during orchiectomy under field conditions. HighlightsIn equine practice short anaesthesia is commonly required for minor surgical procedures.In laterally recumbent horses hypoxemia is the most relevant side effect.In this study, tiletamine/zolazepam association produced a good‐quality anesthesia.The anesthesia and analgesia obtained with this protocol was good.

Marsupialization and sclerotherapy with povidone iodine and ethanol of a branchial remnant cyst in an Arabian filly

ABSTRACT Branchial remnant cysts are an uncommon cause of masses of the throatlatch area in horses. Two methods of treatment have been proposed in literature, both with complications. This manuscript proposes a method (marsupialization and sclerotherapy) for the treatment of a cyst in a 1.5-year-old Arabian filly. Diagnosis was made by ultrasonographic, radiographic and endoscopic examinations, revealing an anechoic fluid-filled structure and a well-defined capsule not in communication with other structures. After emptying the cyst, the skin was sutured circumferentially to the cyst wall; it was then flushed first with a solution of ethanol and povidone-iodine, then with sterile saline. Eight months after surgery, the filly had no recurrence of the cyst and the stoma was healed.

Pharmacokinetic profile and partitioning in red blood cells of romifidine after single intravenous administration in the horse

Abstract The aims of this study were to assess the plasma concentrations of romifidine in horses after intravenous injection, to evaluate the red blood cell (RBC) partitioning of the anaesthetic drug, and to improve knowledge regarding its sedative effect in horses describing the pharmacokinetic model. Eight adult Standardbred horses received a single bolus of romifidine at a dosage of 100 μg/kg. Blood samples (5 mL) were collected immediately before romifidine administration (t 0), and at 2, 5, 10, 15, 20, 25, 30, 40, 50, 60, 75, 90, 105, 120, 150 and 180 min after injection. A sedation score was recorded at the same time. The romifidine concentrations in plasma and red blood cells were determined by high performance liquid chromatography (HPLC). The plasma and red blood cell concentrations were correlated with the sedation at each time point. Romifidine produced a satisfactory level of sedation in all animals. The sedation was detectable in all horses for up to 105 min. All the animals returned to normal without any behavioural changes at 180 min. The romifidine concentrations in the red blood cells were significantly higher (P < 0.01) at all time points than those in the plasma. The T1/2β was 148.67 ± 61.59 min and body clearance was 22.55 ± 6.67 mL/kg per min. The results showed that after a single bolus administration of romifidine, a partitioning in the RBCs was detected.

Ultrasound guided spinal catheter insertion in piglet: preliminary results

OBJECTIVE To describe the ultrasound (US) evaluation of the cervical, thoracic and lumbar spinal tracts in piglets and to evaluate the feasibility of the ultrasound guided spinal catheter placement in newborn and paediatric piglets. STUDY DESIGN Prospective experimental study. ANIMALS A total of two piglet cadavers (age, 7 and 14 days) and eight commercial crossbreed piglets divided into four groups according to age: 7 (P7), 14 (P14), 21 (P21) and 28 (P28) days. METHODS In the first part of the study an ultrasound examination of the spinal tract was performed in piglet cadavers applying the transverse and the longitudinal approaches in sternal and lateral recumbencies. In the second phase, the piglets were anaesthetized with sevoflurane. A US examination with a 10 MHz linear probe was performed and a spinal catheter was introduced between the spinous processes of L2 and L3 lumbar vertebrae using an in-plane technique and its advancement was monitored with the probe. At the end of procedure, the catheter was removed. The piglets recovered from anaesthesia and were monitored for one week. RESULTS In phase I the authors identified the paramedian longitudinal approach as the most feasible for spinal structure evaluation in piglets. In phase II, the paramedian longitudinal views enabled a good visualization of the spinal cord and of the catheter advancement up to the cisterna magna in groups P7 and P14. In groups P21 and P28 it was not possible to visualize the neuroaxial structures and the spinal catheter using the same approach. No clinical alterations were recorded during the procedure or the following days. CONCLUSIONS AND CLINICAL RELEVANCE US-guided spinal catheter placement appeared a feasible technique in piglets younger than 14 days but it is not useful in older piglets.

Proteinase-activated receptor 2 distribution and expression in equine small intestine tracts following herniation through the epiploic foramen

Proteinase-activated receptor 2 (PAR2) is a G-protein-coupled receptor for trypsin and mast cell tryptase; it is highly expressed at the intestinal level with multiple functions, such as epithelial permeability and intestinal motility. The aim of the study was to evaluate the distribution and expression of proteinase-activated receptor 2 in the small intestine during herniation through epiploic foramen. In this prospective clinical study, eight horses admitted for colic and which underwent exploratory laparotomy were considered. During surgery, the jejunum or the ileum was sampled by enterectomy. Morphological examination (histology, PAR2 immunohistochemistry) and molecular biology analysis (western blot and quantitative polymerase chain reaction) were carried out on the resected intestinal samples. The Marginal Injured Tracts (MITs) and Central Injury Tracts (CITs) were defined as the oral and caudal marginal segments of the resected bowel tract and as the geometric centre of the intestinal ischaemic lesion length, respectively. The PAR2 immunoreactivity was particularly evident in the epithelial cells, with higher immunoreactivity in the MIT rather than in the CIT. Moreover, a different immune localisation was observed in the MITs at the cell membrane level and in the CITs in the cytoplasm. No statistical difference was observed in PAR2 mRNA and protein (44kDa) expression between the MIT and the CIT. The PAR2 protein content in the intestinal tracts which were removed from horses with herniation was lower when compared with the control animals. This study provided data concerning the PAR2 presence and distribution in horses with intestinal herniation through the epiploic foramen.