Head and tail rope-assisted recovery improves quality of recovery from general anaesthesia in horses undergoing emergency exploratory laparotomy.

BACKGROUND: In equine anaesthesia, the recovery period is critical, accounting for most anaesthesia-related fatalities reported. Horses may recover unassisted or may be assisted, for example, using a head and tail rope recovery method. OBJECTIVES: To compare the impact of head and tail rope and unassisted recovery method on quality of recovery in horses undergoing colic surgery under general anaesthesia (GA). STUDY DESIGN: Single centre retrospective cross-sectional study, with prospective model performance analysis. METHODS: Clinical data were obtained from horses undergoing emergency exploratory laparotomy over a 6-year period. Multivariable logistic regression analysis was used to identify the perioperative factors that affect quality of recovery. The final prediction model was assessed prospectively. RESULTS: Records from 502 general anaesthetics (490 horses) were included. Multivariable logistic regression analysis showed that head and tail rope recovery (OR 2.2, 95% CI 1.4-3.3, P < .001) and sevoflurane administration (OR 1.6, 95% CI 1.2-2.3, P = .02) were associated with better quality of recovery when compared with unassisted recovery and isoflurane administration respectively. Increasing GA duration (OR 1.0, 95% CI 0.99-1.0, P = .03), increasing intraoperative dosages (in mg/kg) of thiopental (OR 0.85, 95% CI 0.75-0.98, P = .02) or ketamine (OR 0.67, 95% CI 0.46-0.99, P = .04) were linked to poor quality of recovery. No statistically significant difference was found between recovery groups in terms of mortality. MAIN LIMITATIONS: The clinical prediction model obtained is only applicable to the specific facilities, recovery methodology, referral population and anaesthetic protocols practiced at our institution. CONCLUSIONS: Head and tail rope recovery is significantly associated with better quality of recovery, compared with unassisted recovery, in horses undergoing emergency exploratory laparotomy. Sevoflurane administration, in detriment of isoflurane, was associated with better quality of recovery. Other risk factors, such as increasing GA duration, the use of higher intra-operative dosages of ketamine and/or thiopental, were associated with poor quality of recovery.

Ultrasound-guided erector spinae plane block in horses: a cadaver study.

OBJECTIVES: To describe dye distribution and spinal nerve involvement after a simulated erector spinae plane (ESP) block performed on fresh equine cadavers. STUDY DESIGN: Experimental cadaver study. ANIMALS: A group of 11 adult equine cadavers. METHODS: The spinal region surrounding the sixteenth thoracic vertebra (Th16) of one cadaver was removed and underwent magnetic resonance imaging. In 10 adult equine cadavers [body weight, 549 ± 58 kg (mean ± standard deviation)], 0.2 mL kg-1 of a 50:1 2% lidocaine/dye solution was injected bilaterally (n = 20 injections) into the fascial plane between the transverse process of Th16 and the erector spinae muscles. An in-plane ultrasound-guided technique with a convex transducer was used to guide injection. Dissection was performed immediately following injection. The craniocaudal and lateral extent of dye distribution was measured (cm) and the number of vertebral bodies involved were counted (n = 20). Abdominal and thoracic cavities as well as the epidural space were also examined for presence of dye (yes/no) (n = 20). Further dissection was performed to evaluate if staining of the dorsal and ventral rami of the spinal nerves and sympathetic chain occurred (n = 14). RESULTS: The thoracolumbar fascia was stained in 17/20 (85%) injections and three injections terminated intramuscularly. Multisegmental staining of the dorsal rami was observed in the 14 injections in which staining was evaluated. Ventral rami staining was observed in 3/14 injections where staining was evaluated. Epidural migration was observed in 4/20 (20%) injections. No evidence of dye was found in the thoracic and abdominal cavities or on the sympathetic chain. CONCLUSIONS AND CLINICAL RELEVANCE: The ESP block may prove beneficial to desensitize structures innervated by the dorsal rami of the thoracic spinal nerves. Further investigation is necessary to evaluate complications caused by epidural contamination.

Expression of purinergic P2X receptor subtypes 1, 2, 3 and 7 in equine laminitis.

Tissue sensitisation and chronic pain have been described in chronic-active laminitis in the horse, making treatment of such cases difficult. Purinergic P2X receptors are linked to chronic pain and inflammation. The aim of this study was to examine the expression of purinergic P2X receptor subtypes 1, 2, 3 and 7 in the hoof, palmar digital vessels and nerve, dorsal root ganglia and spinal cord in horses with chronic-active laminitis (n=5) compared to non-laminitic horses (n=5). Immunohistochemical analysis was performed on tissue sections using antibodies against P2X receptor subtypes 1-3 and 7. In horses with laminitis, there was a reduction in the thickness of the tunica media layer of the palmar digital vein as a proportion of the whole vessel diameter (0.48±0.05) compared to the non-laminitic group (0.57±0.04; P=0.02). P2X receptor subtype 3 was expressed in the smooth muscle layer (tunica media) of the palmar digital artery of horses with laminitis, but was absent in horses without laminitis. There was strong expression of P2X receptor subtype 7 in the proliferating, partially keratinised, epidermal cells of the secondary epidermal lamellae in the hooves of horses with laminitis, but no immunopositivity in horses without laminitis.

A study of the correlation between objective and subjective indices of recovery quality after inhalation anaesthesia in equids.

OBJECTIVE: To examine the association between objective and subjective descriptors used for assessing recovery quality in horses after anaesthesia. STUDY DESIGN: Prospective clinical study. ANIMALS: Two hundred and seventy-six equids (110 mares, 85 entire males and 81 geldings), ASA 1-5, weighing 50-850 kg and aged 1 month - 25 years. METHODS: Recoveries after general anaesthesia were assisted with head and tail ropes by two anaesthetists. One scored dichotomous objective descriptors (DOD) of recovery. Two dichotomous objective scales (DOS) were then generated from those descriptors. The same individual also scored overall recovery quality using a visual analogue scale (VAS). The second anaesthetist scored recovery (good or bad) using a dichotomous subjective scale (DSS). Each DOD, the DSS and VAS were compared with each other using Pearson's chi-square test. DOSs were compared to the DSS using Wilcoxon's test and to the VAS using a Spearman's correlation test. RESULTS: Most DODs were associated (p < 0.05) with DSS and VAS. The DSS was not associated with resting/not resting in sternal recumbency (p = 0.535) nor with the time spent in sternal recumbency (p = 0.09). VAS and DSS scores were strongly associated (p < 0.0001). The two DOSs were in agreement with DSS (p < 0.0001) and negatively correlated to VAS (r(1)(2) = 0.38, r(2)(2) = 0.34, respectively, p-value <0.0001). CONCLUSION: Objective descriptors were linked closely with the subjective evaluations of recovery quality except for the presence or absence of a sternal recumbency phase and its duration. CLINICAL RELEVANCE: These components may not be essential in recovery scoring systems. The DOS were in agreement with DSS and VAS and could be a useful tool for further studies on recoveries.

Post-anaesthetic pulmonary oedema in horses: a review.

OBJECTIVES: To review information on the pathogenesis, diagnosis and treatment of post-anaesthetic pulmonary oedema in horses. DATABASES USED: Pubmed 1970-present, personal files.

TFE3 immunoreactivity in alveolar soft part sarcoma of the uterine cervix: case report.

SUMMARY: : Alveolar soft part sarcoma (ASPS) is an uncommon neoplasm that has only rarely been reported in the female genital tract. We report a case of incidentally discovered ASPS in the uterine cervix of a 39-year-old woman that exhibited immunoreactivity for TFE3, a recently described marker of ASPS. Strong nuclear immunoreactivity for TFE3 in tumors characterized by a chromosomal translocation involving the TFE3 gene has been reported in ASPS and a subset of pediatric renal cell carcinomas. This translocation, t(X;17)(p11;q25), fuses the TFE3 transcription factor gene on Xp11 to a novel gene on 17q25, designated ASPL. In our case, the neoplastic nuclei were strongly positive for TFE3. To the best of our knowledge, this is the first report of ASPS of the female genital tract with immunoreactivity for TFE3. Other interesting findings in our case were the small size of the tumor and the absence of clinical symptoms.