Dal naso al cervello: effetti clinici della dexmedetomidina per via intranasale nel cane.

Introduzione: La somministrazione intranasale di farmaci per indurre effetti sistemici è una realtà clinica legittimata dalle insolite proprietà di assorbimento della mucosa nasale. Tra molte altre sostanze, la somministrazione intranasale di molecole neurotrope, quali quelle anestetiche, si avvantaggia della via naso-cervello, nota alla medicina antica, ma solo da poco riscoperta in campo clinico. Dopo aver descritto la via intranasale e caratterizzato la dexmedetomina, già impiegata nell’uomo per via IN, vengono riportate gli studi di anestesia intranasale in vari ordini di animali presenti in letteratura. Obiettivo: Il presente studio si pone l’obiettivo di valutare l’efficacia clinica e gli effetti sulla funzionalità degli apparati cardiocircolatorio e respiratorio prodotti dalla dexmedetomidina (DEX) nel cane, dopo somministrazione per via intranasale (IN), confrontandoli con quelli conseguenti la più comune via di somministrazione intramuscolare (IM). Materiali e metodi: Sono stati inclusi nello studio venti cani, tutti appartenenti alle classi di rischio anestesiologico ASA I o II, divisi, secondo randomizzazione, in due gruppi per la somministrazione IN o IM di DEX. In entrambi i gruppi veniva somministrata DEX (Dexdomitor 0.05%, Pfizer Italia srl, Italy) alla dose di 0.02 mg/kg. Nei soggetti del gruppo IM la DEX veniva somministrata nel ventre del muscolo retto femorale, mentre nel gruppo IN, la stessa dose di DEX veniva somministrata per via intranasale, con l’ausilio di un atomizzatore MAD (Mucosal Atomization Device, MAD 300, Wolfe Tory Medical Inc., Salt Lake City, USA), in grado di ottimizzare la distribuzione e l’assorbimento del farmaco all’interno delle cavità nasali. Tutti i soggetti, dal momento della somministrazione e per i 45 min. successivi, venivano monitorati costantemente i parametri vitali e il grado di sedazione annotandoli in cartella ogni 5 min. Per valutare la variabilità all’interno di gruppi e tra i due gruppi, sono stati utilizzati: un’analisi della varianza a due vie (2-way ANOVA) per i dati parametrici, mentre per i dati non parametrici è stato impiegato il test Scheier Ray Hare. L’analisi post hoc è stata eseguita con il test di Sidak, il test di Mann-Whitney U-test o il test di Tukey, in relazione al tipo di distribuzione. Per tutti i test la significatività è stata posta a p < 0.05. Risultati: La sedazione è risultata efficace in tutti i soggetti di entrambi i gruppi, mentre non è stata riscontrata alcuna differenza statisticamente significativa tra i due gruppi nella latenza d’azione del farmaco (IN 6.3 ± 3.3 minuti vs IM di 9.4 ± 4.6 minuti). Il grado di sedazione (SS) è risultato significativamente più alto nel gruppo IN rispetto al gruppo IM (p < 0.001) a tutti i tempi a partire da 10 minuti dopo la somministrazione di DEX. Per quanto concerne i parametri vitali, la frequenza cardiaca è risultata significativamente più alta nel gruppo IN rispetto al gruppo IM (p < 0.001); in particolare, in corrispondenza del picco di sedazione, la frequenza cardiaca è risultata diminuita del 18% rispetto ai valori basali nel gruppo IN, mentre nel gruppo IM la diminuzione della frequenza cardiaca ha raggiunto una riduzione in percentuale del 56%. Infine, non sono state riscontrate differenze statisticamente significative tra i due gruppi nell’andamento della frequenza respiratoria (p = 0.067) e saturazione dell’ossigeno nel sangue (p = 0.127). Conclusioni: Nonostante abbia prodotto una sedazione più profonda, la somministrazione IN ha determinato una minore incidenza della bradicardia. Il passaggio diretto dal naso al cervello, dimostrato da diversi studi nell’uomo e negli animali, può aver favorito una maggiore concentrazione del farmaco nel SNC ed una sua minore distribuzione sistemica, determinando così una parziale riduzione degli effetti periferici della DEX. La somministrazione IN di DEX potrebbe costituire un’alternativa meno invasiva e di pari efficacia alla via di somministrazione intramuscolare

Intubation in Swine: What Recumbency to Choose?

Endotracheal intubation (ETI) is challenging in pigs. We compared the number of attempts and time to perform ETI, and the subjective perception of ease, while the animal was positioned in dorsal (DR) or sternal (SR) recumbency, as well as assessed whether operator experience influences the outcome. Participants were divided into three groups: undergraduates (ST; veterinary students), graduates (GR; veterinarians without specific anaesthesia training) and experts (EX; veterinary anaesthesia intern/resident and diplomate of the European College of Veterinary Anaesthesia and Analgesia). Each participant intubated one freshly euthanised pig in DR and ST. Number of attempts and time to correctly perform ETI, number of oesophageal intubations and answers to Likert-scale questions on larynx visualization and ease of endotracheal tube introduction and advancement were recorded. Thirty-three participants were enrolled (15 ST, 10 GR and 8 EX). Less attempts (p = 0.002) and time (p = 0.002) to correctly perform ETI were needed in SR for the ST group. In 21/119 and 5/48 ETI attempts, oesophageal intubation was performed in DR and SR, respectively. Larynx visualization (p &lt; 0.001) and endotracheal tube introduction (p &lt; 0.001) were perceived as easier in SR for the ST group. No difference between recumbencies was found in perceived ease to advance the endotracheal tube. For inexperienced operators, intubation in SR can be recommended

Normal ultrasonographic features of loggerhead (Caretta caretta) eyes

The Loggerhead sea turtle (Caretta caretta) is widely distributed in the Mediterranean Sea but, like other sea turtles, it is considered a threatened species. Improving anatomical knowledge on normal aspects of the species is important for correct diagnosis and proper therapy and, therefore, for improving the chances of a complete recovery and a fast reintroduction into the wild for a greater number of sea turtle bycatch and other mishaps. For this reason, 15 Loggerhead turtles, with clinically healthy eyes, were submitted to ocular ultrasonographic (US) examinations. The US exam was quick, non-invasive, and simple to perform and permitted researchers to assess all the ocular features

Normal ultrasonographic features of loggerhead (Caretta caretta) eyes

The Loggerhead sea turtle (Caretta caretta) is widely distributed in the Mediterranean Sea but, like other sea turtles, it is considered a threatened species. Improving anatomical knowledge on normal aspects of the species is important for correct diagnosis and proper therapy and, therefore, for improving the chances of a complete recovery and a fast reintroduction into the wild for a greater number of sea turtle bycatch and other mishaps. For this reason, 15 Loggerhead turtles, with clinically healthy eyes, were submitted to ocular ultrasonographic (US) examinations. The US exam was quick, non-invasive, and simple to perform and permitted researchers to assess all the ocular features

Clinical efficacy of an ultrasound-guided bilateral rectus sheath block for umbilical hernia repair in calves: A prospective randomized trial

Introduction: Surgical umbilical hernia repair is a frequent procedure in newborn calves, requiring mandatory pain management. This study aimed to develop an ultrasound-guided rectus sheath block (RSB) and to evaluate its clinical efficacy in calves undergoing umbilical herniorrhaphy under general field anesthesia. Methods: Gross and ultrasound anatomy of the ventral abdomen and the diffusion of a new methylene blue solution after injection within the rectus sheath were described in seven fresh calf cadavers. Then, fourteen calves undergoing elective herniorrhaphy were randomly assigned to receive either bilateral ultrasound-guided RSB with 0.3 mL/kg of bupivacaine 0.25% and 0.15 µg/kg of dexmedetomidine or 0.3 mL/kg of 0.9% NaCl (control). Intraoperative data included cardiopulmonary variables and anesthetic requirements. Postoperative data included pain scores, sedation scores and peri-incisional mechanical threshold assessed by force algometry at specific time points after anesthetic recovery. Treatments were compared using Wilcoxon rank-sum, Student's t-test, and Cox proportional hazard model as appropriate. Mixed effect linear models on rank, with random effect calf; fixed effects time, treatment, and their interaction were used to compare pain scores and mechanical thresholds over time. Significance was set at p = 0.05. Results and Discussion: Calves receiving RSB recorded lower pain scores between 45 – 120 minutes (p < 0.05) and at 240 min after recovery (p = 0.02). And they recorded higher mechanical thresholds between 45 and 120 min after surgery (p < 0.05). Ultrasound-guided RSB provided effective perioperative analgesia in calves undergoing herniorrhaphy under field conditions

Using geographical information system for spatial evaluation of canine extruded disc herniation

Disc herniation is one of the most common pathologies of the vertebral column in dogs. The aim of this study was to develop a geographical information system (GIS)-based vertebral canal (VC) map useful for spatial evaluation of extruded disc herniation (EDH) in dogs. ArcGIS® was used to create two-dimensional and three-dimensional maps, in which the VC surface is divided into polygons by lines representing latitude and longitude. Actual locations and directions of the herniated disc material were assessed by a series of 142 computer tomographies of dogs collected between 2005 and 2013. Most EDHs were located on the cervical and transitional regions (thoraco-lumbar and lumbo-sacral) and shown at the level of the ven- tro-cranial and ventro-central polygons created. Choropleth maps, highlighting the distribution and the location/direction patterns of the EDHs throughout the VC, were produced based on the frequency of the ailment. GIS proved to be a valuable tool in analysing EDH in dogs. Further studies are required for biomechanical analysis of EDH patterns

Endoscopic and Surgical Removal of Gastrointestinal Foreign Bodies in Dogs: An Analysis of 72 Cases

In emergency veterinary practice, gastrointestinal foreign body (GFB) removal is a common procedure that is performed with different techniques, such as endoscopy or surgery. The aims of this retrospective, multicentre, clinical study were to report the common locations and types of objects recovered and to investigate clinical factors and outcomes in dogs after surgical or endoscopic treatment for GFB removal. Records of dogs with a GFB diagnosis referred to the Teaching Veterinary Hospital or treated in three different veterinary hospitals from September 2017 to September 2019 were examined. The data obtained from each case included breed, age, clinical signs at presentation, duration of clinical signs, type and location of the GFB, treatment, length of hospitalisation and outcome. Seventy-two dogs were enrolled in the study. There were 42 males (58%) and 30 females (42%). The median age was 36 months (range: 3 months to 8 years). Endoscopic retrieval was performed in 56% of GFBs (located in the stomach or duodenum), whereas 44% of dogs underwent surgery. The type of FB detected varied greatly: kid toy (14%), metallic object/coin (13%), cloth (13%), sock (8%), ball (8%), plastic material (8%), peach stone (7%), fishhook (6%), sewing needle (4%), hair tie (4%), pacifier (3%), plant materials (3%) and others (9%). Moreover, the FBs were classified as sharp (13%, n = 9), pointed (33%, n = 24), blunt (26%, n = 19), or linear (28%, n = 20). In this study, 68% of FBs were localised in the stomach, 25% in the intestinal tract (50% duodenum, 28% jejunum, and 22% ileum), and 7% in both the stomach and small intestine. The type of GFB was not significantly associated with age, site or breed. There was a significant association between the type of GFB and sex: if the dog was male, there was a 38% probability of ingesting linear GFBs. The dog survival rate was 100% in cases treated by gastric endoscopic or surgical removal, 94% in cases treated with enterotomy and 33% in cases in which enterectomy was necessary. Enterectomy and multiple surgical sites were associated with a poor outcome. The presence of vomiting for more than 24 h was significantly associated with death

Geographical information system analysis on road accidents involving wandering dogs in the urban area of Naples

In this study, the spatial distribution of road accidents involving wandering dogs on urban roads of Naples was assessed using kernel density estimation (KDE). The study included 423 dogs victim of road collisions in the period 2012-2015 collected from the medical records of Interdepartmental Centre of Veterinary Radiology, of Pathological Anatomy Service, of Veterinary Teaching Hospital, "Federico II" University of Naples, and of Veterinary Hospital Attendance of the Local Public Health Unit Napoli1. There were a significant prevalence of young male dogs and the KDE demonstrated the presence of five hotspots in five city neighbourhoods. All areas with the highest KDE were found to be peripheral zones in which wide green areas, uncultivated or cultivated, merged with built areas and crossed by large straight roads with a lot of intersections. Wandering dogs as other animals represent a mounting problem on urban roads in Italy, despite of the effort to reduce these populations. Better knowledge of this phenomenon is important with reference to taking countermeasures and improve road safety. It is also important with reference to One Health and the Decade of Action for Road Safety 2011- 2020 of the United Nations

Sedation via the intranasal route in dogs

In human and veterinary clinical practice the intranasal (IN) route has long been used for the treatment of local and upper respiratory tract diseases. In the last decades this route attracted more interest for systemic drug administration because it is a non-invasive, safe and suitable method allowing rapid onset of action and avoidance of gastrointestinal tract constraints as well of hepatic first-pass metabolism (1). In humans, especially in children and uncooperative patients, the IN route is increasingly used for sedation, thanks to the intense absorption power of the nasal mucosa and to the fast, direct transport of neurotrophic molecules to the Central Nervous System via the olfactory nerves (1). In animals the IN route is not adequately explored although in most species such as dogs, the olfactory epithelium is lined with hundreds of millions of sensory neurons (2). In dogs, the IN administration of 0,5 mg/kg of diazepam for emergency treatment of seizures has been shown to be an effective, alternative route for easy and quick administration of such anticonvulsant drug (3). In clinical settings we administered via the IN route different anesthetic agents such as dexmedetomidine, butorphanol, midazolam and fentanyl to induce sedation and analgesia in dogs. To improve drug absorption by reducing particles diameter and the risk of its expulsion we used a commercial Mucosal Atomization Device (MAD®) produced for humans. We reported(4) that the intranasal administration is easy to perform, painless and well tolerated in dogs. In our experience the IN administration of 20 μg/kg of dexmedetomidine produced effective sedation comparable to that following conventional administration routes; further to that, the IN route showed a shorter onset time compared to the intramuscular route, devoid of undesirable effects. In the same study we showed that the sedative and analgesic proprieties of dexmedetomidine given by IN route can be enhanced by its combination with 0,1 mg/kg of butorphanol administered as a drug mixture (4). Among opioids, fentanyl is particularly suitable for IN administration due to its high lipophily favouring a rapid action onset highly desirable for acute pain treatment; such quality, in fact, promoted different IN formulation of fentanyl (Instanyl®, PecFent®) available on the market for treatment of breakthrough pain in humans (1). The IN administration of fentanyl favourably affects the molecule pharmacokinetics in dogs. In our experience, 4 μg/kg of fentanyl atomized on the nasal mucosa showed a very short onset time (about 9 min) providing a full analgesic effect lasting about 35 minutes (5), slightly longer compared to the 30 minutes effects reported after IV administration in dogs. In conclusion the IN route constitute a non-invasive and effective route for anesthetic drug administration, favouring prompt CNS effects in dogs, with the potential for enhancing and extending the effects of neurotrophic molecules thanks to their direct transport to forebrain trough the olfactory nerves. So far, to our knowledge, no adverse effects linked to the nature of different molecules and to their contact with and absorption trough the nasal mucosa have been reported in humans and in animals

Preclinical imaging anesthesia in rodents

Despite the outstanding progress achieved by preclinical imaging science, laboratory animal anesthesia remains quite stationary. Ninety percent of preclinical imaging studies are carried on small rodents (mice and rats) anesthetized by outdated injectable and/or inhalation agents. A need for imaging awake (conscious) animals is questionably registered mainly for brain research, for phMRI and for accomplishing pain and analgesia studies. A need for improving current rodent anesthesia protocols and for enforcing the 3Rs paradigm is sought. Patient monitoring throughout the procedure and recovery phases, as well as vital parameter's data must be recorded in basic consciousness states and during imaging sessions. A multidrug approach is suggested to overcome the limits of monoanesthesia and well-timed physiological data are required to ground findings and to interpret imaging data