2. Universidad Cardenal Herrera-CEU

Background: Patient safety is essential in small animal anaesthesia. Thisstudy aimed to assess anaesthesia-related deaths in cats worldwide, identifyrisk and protective factors and provide insights for clinical practice.Methods: A prospective multicentre cohort study of 14,962 cats from198 veterinary centres across different countries was conducted. Data onanaesthesia-related deaths, from premedication up to 48 hours postex-tubation, were collected. Logistic regression was used to analyse patientdemographics, American Society of Anesthesiologists (ASA) classification,procedure type and anaesthetic drugs.Results: The anaesthesia-related mortality was 0.63%, with 74.5% of deathsoccurring postoperatively. Cats with cachexia, a higher ASA status or whounderwent abdominal, orthopaedic/neurosurgical or thoracic proceduresexhibited elevated mortality. Mechanical ventilation use was associated withincreased mortality. Mortality odds were reduced by the use of alpha2 -agonistsedatives, pure opioids in premedication and locoregional techniques.Limitations: Limitations include non-randomised sampling, potentialbiases, unquantified response rates, subjective death cause classification andlimited variable analysis.Conclusions: Anaesthetic mortality in cats is significant, predominantlypostoperative. Risk factors include cachexia, higher ASA status, specificprocedures and mechanical ventilation. Protective factors include alpha2 -agonist sedatives, pure opioids and locoregional techniques. These findingscan help improve anaesthesia safety and outcomes. However, further researchis required to improve protocols, enhance data quality and minimise risks.

This study compared four methods to provide intraoperative analgesia during canine ovariohysterectomy in a veterinary teaching hospital. A retrospective study was designed to assess the nociceptive response, cardiorespiratory stability, quality of recovery and complications of four analgesic protocols: epidural analgesia (EPIDURAL group), Quadratus Lumborum block (QLB group), Transversus Abdominis Plane block (TAP group), and just systemic analgesia (GENERAL group). Undergraduate students carried out all the loco-regional techniques under the direct supervision of a qualified anaesthetist. A total of 120 cases met the inclusion criteria and were included in the study and were distributed as follows: 22, 27, 32 and 39 cases with EPIDURAL, GENERAL, QLB and TAP groups, respectively. Data were analysed with statistical software R using different statistical methods. Significant differences among groups were defined as p < 0.05. Based on our results, all the groups needed the same number of rescue analgesia during the intra-operative period. The use of loco-regional techniques anticipated a better quality of recovery compared with the general group. The EPIDURAL group showed a statistically lower expired fraction of sevoflurane. No differences were found regarding complications. In conclusion, these four analgesic methods are suitable and safe to be performed for canine ovariohysterectomy, although loco-regional techniques might have some advantages.

Ultrasound-guided quadratus lumborum block (QLB) is a locoregional technique described in canine cadavers. The aim of this study was to assess a modified approach to QLB to minimise potential complications such as abdominal organ puncture. Nine canine cadavers were included and were positioned in lateral recumbency. An ultrasound-guided QLB was performed on each side. The probe was placed in the transverse position over the lumbar muscles just caudal to the last rib, and a needle was advanced in-plane from a dorso-lateral to a ventro-medial. A volume of 0.2 mL kg􀀀1 of a mixture of iomeprol and methylene blue was injected. Computed tomography (CT) and dissection were performed to evaluate the spreading. Success was defined as staining of the nerve with a length of more than 0.6 cm. Potential complications such as intra-abdominal, epidural, or intravascular spreading of the mixture were also assessed. The CT images showed a T13 to L7 vertebra distribution, with a median of 5 (3–6). Dissection showed staining of the nerves from T13 to L4, with a median of 3 (2–5). No complications were found. This modified approach to QLB is safe and shows similar results to the previous studies in canine carcass.