Attitudes of Spanish-speaking veterinarians interested in anaesthesia towards use of total intravenous anaesthesia in dogs: a survey study

ObjectivesTo describe Spanish-speaking veterinary anaesthetists’ attitudes towards use of total intravenous anaesthesia (TIVA) in dogs.Study designProspective online voluntary survey.PopulationData from 300 answered surveys.MethodsAn anonymous questionnaire was sent via e-mail to representatives of the four largest Spanish-speaking veterinary anaesthesia and analgesia associations. It was distributed through mailing lists (Spain, Argentina, Mexico) or social media (Spain, Chile) to gather information on the use, opinions and perceived advantages of TIVA, as well as on preferred alternatives to isoflurane for providing general anaesthesia. Logistic regression was used to test for response associations.ResultsA total of 275 (92%) respondents had used TIVA (24% rarely, 36% sometimes, 40% very often or always). There was an association between a higher rate of TIVA usage and a low specialization level, less clinical experience and unavailability of anaesthetic gas scavenging systems. The main reasons for not using TIVA were lack of familiarity with the technique (92%), unavailability of infusion pumps (32%), established institutional anaesthetic protocol (32%), and technical difficulty (20%). Among frequent TIVA users, a higher proportion reported the greater ease of TIVA use (52%) compared to those that did not perceive such benefit (17%) [odds ratio (OR) = 5.2; 95% confidence interval (CI95), 1.7–16.6; p = 0.004). More respondents did not consider TIVA more expensive (60%) (OR = 2.1; CI95, 1.0–4.3; p = 0.034), more difficult to perform (59%) (OR = 2.5; CI95, 1.3–4.9; p = 0.006) or to manage the equipment (53%) (OR = 3.3; CI95, 1.4–7.8; p = 0.008), than inhalational anaesthetics. During isoflurane shortages, respondents reportedly preferred using an alternative inhalational agent (59%) rather than TIVA (47%).Conclusions and clinical relevanceTIVA use is widespread among veterinarians within the surveyed associations. Frequent TIVA users reported greater perceived advantages. In situations of isoflurane shortage, an alternative inhalational anaesthetic was preferred over TIVA.     

Effect of torsemide and furosemide on clinical,laboratory, radiographic and quality of life variables in dogs with heart failure secondary to mitral valve disease

ObjectivesDiuretic therapy reduces preload and relieves congestion secondary to cardiac dysfunction. Torsemide (torasemide) is a loop diuretic with longer duration of action, decreased susceptibility to diuretic resistance, and adjunctive aldosterone antagonist properties compared with furosemide. We hypothesized that torsemide would be well tolerated and no less effective than furosemide at diuresis, control of clinical signs, and maintenance of quality of life (QOL) in dogs with congestive heart failure (CHF).Animals, materials and methodsSeven client-owned dogs with stable CHF receiving twice daily oral furosemide and adjunctive medications. Utilizing a double-blinded, randomized, crossover design, dogs were administered either oral furosemide at their current dose or an equivalent oral dose of torsemide (1/10 of the daily furosemide dose divided into twice daily dosing) on day 0. Crossover occurred at day 7 and the study ended on day 14. Clinical, laboratory, radiographic, and QOL variables were evaluated on days 0, 7 and 14.ResultsNo dogs developed recurrent CHF during the study. Mean furosemide dose on day 0 was 5.13 mg/kg/day (range 2.8–9.6). Following torsemide treatment, creatinine (P = 0.020), urea nitrogen (P = 0.013), phosphorus (P = 0.032), albumin (P = 0.019), carbon dioxide (P = 0.015) and anion gap (P = 0.005) were significantly increased, and urine specific gravity (P = 0.004) and chloride (P = 0.021) were significantly decreased compared with furosemide dosing. No differences in QOL were found.ConclusionsResults indicate that torsemide is equivalent to furosemide at controlling clinical signs of CHF in dogs and is likely to achieve greater diuresis vs. furosemide. Larger clinical trials evaluating torsemide as a first or second-line loop diuretic for congestive heart failure in dogs are warranted.     

Randomization,blinding, data handling and sample size estimation in papers published in Veterinary Anaesthesia and Analgesia in 2009 and 2019

ObjectiveTo evaluate reporting of items indicative of bias and weak study design.Study designLiterature survey.PopulationPapers published in Veterinary Anaesthesia and Analgesia.MethodsReporting of randomization, blinding, sample size estimation and data exclusion were compared for papers published separated by a 10 year interval. A reporting rate of more than 95% was considered ideal. The availability of data supporting results in a publicly accessible repository was also assessed. Selected papers were randomized and identifiers removed for review, with data from 59 (57 in 2009, two in 2008) and 56 (52 in 2019, four in 2018) papers analyzed. Items were categorized for completeness of reporting using a previously published operationalized checklist. Two reviewers reviewed all papers independently.ResultsFull reporting of randomization increased over time from 13.6% to 85.7% [95% confidence interval (CI), 57.8–86.6%; p < 0.0001], as did sample size estimation (from 0% to 20%; 95% CI, 7.6–32.4%; p = 0.002). Reporting of blinding (49.2% and 50.0%; 95% CI, –18.3% to 20.0%; p = 1.0) and exclusions of samples/animals (39.0% and 50.0%; 95% CI, –8.8% to 30.8%; p = 0.3) did not change significantly. Data availability was low (2008/2009, zero papers; 2018/2019, two papers). None of the items studied exceeded the predetermined ideal reporting rate.Conclusions and clinical relevanceThese results indicate that reporting quality remains low, with a risk of bias.     

Efficacy of tramadol for postoperative pain management in dogs: systematic review and meta-analysis

ObjectiveTo evaluate the evidence of analgesic efficacy of tramadol for the management of postoperative pain and the presence of associated adverse events in dogs.Databases usedA comprehensive search using PubMed/MEDLINE, LILACS, Google Scholar and CAB databases with no restrictions on language and following a prespecified protocol was performed from June 2019 to July 2020. Included were randomized controlled trials (RCTs) performed in dogs that had undergone general anesthesia for any type of surgery. Two authors independently classified the studies, extracted data and assessed their risk of bias using Cochrane’s tool. RevMan and GRADE methods were used to rate the certainty of evidence (CoE).ConclusionsOverall 26 RCTs involving 848 dogs were included. Tramadol administration probably results in a lower need for rescue analgesia versus no treatment or placebo [moderate CoE; relative risk (RR): 0.47; 95% confidence interval (CI): 0.26–0.85; I² = 0%], and may result in a lower need for rescue analgesia versus buprenorphine (low CoE; RR: 0.50; 95% CI: 0.20–1.24), codeine (low CoE; RR: 0.75; 95% CI: 0.16–3.41) and nalbuphine (low CoE; RR: 0.05; 95% CI: 0.00–0.72). However, tramadol administration may result in an increased requirement for rescue analgesia versus methadone (low CoE; RR: 3.45; 95% CI: 0.66–18.08; I² = 43%) and COX inhibitors (low CoE; RR: 2.27; 95% CI: 0.68–7.60; I² = 45%). Compared with multimodal therapy, tramadol administration may make minimal to no difference in the requirement for rescue analgesia (low CoE; RR: 1.12; 95% CI: 0.48–2.60; I² = 0%). Adverse events were inconsistently reported and the CoE was very low. The overall CoE of the analgesic efficacy of tramadol for postoperative pain management in dogs was low or very low, and the main reasons for downgrading the evidence were risk of bias and imprecision.     

The pharmacokinetics of pimobendan enantiomers after oral and intravenous administration of racemate pimobendan formulations in healthy dogs

Pimobendan is a benzimidazole‐pyridazinone derivative, marketed as a racemic mixture for the management of canine heart failure. Pharmacokinetics of the enantiomers of pimobendan and its oral bioavailability have not been described in dogs. The aim of this study was to describe pharmacokinetics of three formulations of pimobendan in healthy dogs: the licensed capsule product, and novel liquid and intravenous formulations. A three‐period, nested randomized two‐treatment crossover design was used. Pimobendan was administered p.o. at 0.25 and i.v. at 0.125 mg/kg. Blood and plasma samples were analysed by liquid chromatography–mass spectrometry. Noncompartmental modelling was used to describe the pharmacokinetics. Parameters were compared between formulations using a general linear model. Bioequivalence of the oral formulations was tested using CI90 for AUC_(0–∞) and C_max. Bioavailability of pimobendan after oral dosing was 70%. Liquid and capsule formulations were bioequivalent only for AUC. The positive enantiomer of pimobendan (PE) had a larger volume of distribution than the negative enantiomer (NE) (281 ± 48 vs. 215 ± 68 mL/kg; P = 0.003) and a shorter half‐life (21.7 vs. 29.9 min; P = 0.004). The NE was distributed more quickly than the PE into blood cells. Enantiomers of pimobendan have differing absorption, distribution and elimination. The pharmacokinetics of pimobendan in healthy dogs was described.     

Minimum anesthetic concentration of isoflurane and sparing effect of midazolam in Quaker parrots (Myiopsitta monachus)

ObjectiveTo determine the effects of midazolam on the minimum anesthetic concentration (MAC) reduction of end-tidal isoflurane concentration (Fe′Iso) measured using an electrical stimulus in Quaker parrots (Myiopsitta monachus).Study designRandomized crossover experimental study.AnimalsA group of six adult Quaker parrots, weighing 98–124 g.MethodsBirds were anesthetized with isoflurane in oxygen delivered by mask, then tracheally intubated and mechanically ventilated. Three treatments were applied with a 4 day interval between anesthetic events. Each anesthetized bird was administered midazolam (1 mg kg⁻¹; treatment MID1), midazolam (2 mg kg⁻¹; treatment MID2) or electrolyte solution (control) intramuscularly. The treatments were administered using a replicated Latin square design and the observers were blinded. Based on a pilot bird, the starting Fe′Iso was 1.8%. After equilibration for 10 minutes, a supramaximal stimulus was delivered using an electrical current (20 V and 50 Hz for 10 ms) and birds were observed for non-reflex movement. The Fe′Iso was titrated by 0.1% until a crossover event was observed. The MAC was estimated using logistic regression.ResultsThe MAC of isoflurane (MAC_ISO) was estimated at 2.52% [95% confidence interval (CI), 2.19–2.85] with a range of 1.85–2.65%. MAC_ISO in MID1 was 2.04% (95% CI, 1.71–2.37) and in MID2 was 1.81% (95% CI, 1.48–2.14); reductions in MAC_ISO from control of 19% (p = 0.001) and 28% (p < 0.001), respectively. Heart rate, temperature, sex and anesthetic time were not different among treatments.ConclusionsMidazolam (1–2 mg kg⁻¹) intramuscularly resulted in a significant isoflurane-sparing effect in response to a noxious stimulus in Quaker parrots without observable adverse effects.Clinical relevanceMidazolam can be used as part of a balanced anesthetic approach using isoflurane in Quaker parrots, and potentially in other psittacine species.     

Avian anaesthesia related mortality and the associated risk factors in a UK zoological collection

ObjectiveTo analyse avian anaesthesia-related mortality in a UK zoological collection over a 5-year period and identify risk factors for mortality.Study designRetrospective cohort study.AnimalsA total of 135 individual birds across 37 species, anaesthetized during 206 events in a UK zoological collection between 1 January 2014 and 30 June 2019 (inclusive).MethodsAnaesthesia records were reviewed and variables such as age, body condition, weight, sex, duration of anaesthesia and health status were collated. Anaesthesia-related mortality was defined as those deaths occurring during anaesthesia and up to 7 days postanaesthesia. Outcome was analysed using multivariable conditional logistic regression. Overall mortality was defined and included birds euthanised during anaesthesia for non-anaesthesia related reasons. Data were summarised as median (range). A value of p < 0.05 was considered significant. Relative risks and 95% confidence intervals (95% CI) were calculated for the association between risk factors and anaesthetic death where a statistically significant difference was found.ResultsThe overall mortality rate was 10.19% (95% CI = 6.06–14.3%), while anaesthesia-related mortality was 3.88% (95% CI = 1.69–7.51%). Birds with an abnormal health status had a 15.53-fold (95% CI = 1.95–123.63) increased risk of death compared with those with a normal health status. The duration of anaesthesia was also a statistically significant risk factor (p = 0.021) in the univariable analysis, but not when combined with health status. No other variables were associated with anaesthesia-related mortality.Conclusions and clinical relevanceAbnormal health status and longer anaesthetic procedures were associated with a significantly increased risk of anaesthesia-related death in this population of birds. It is recommended that anaesthetic duration is minimized, and pre-existing diseases are diagnosed where possible prior to general anaesthesia of birds. Anaesthetizing healthy birds was associated with a low risk of mortality.     

Increased NT-proANP predicts risk of congestive heart failure in Cavalier King Charles spaniels with mitral regurgitation caused by myxomatous valve disease

ObjectivesTo evaluate the predictive value of plasma N-terminal pro-atrial natriuretic peptide (NT-proANP) and nitric oxide end-products (NOx) as markers for progression of mitral regurgitation caused by myxomatous mitral valve disease.AnimalsSeventy-eight privately owned Cavalier King Charles spaniels with naturally occurring myxomatous mitral valve disease.MethodsProspective longitudinal study comprising 312 measurements over a 4.5 year period. Clinical values were recorded, NT-proANP concentrations were measured by radioimmunoassay, and NOx were analyzed colorimetrically. To predict congestive heart failure (CHF), Cox proportional hazards models with time-varying covariates were constructed.ResultsThe hazard ratio for NT-proANP (per 1000 pmol/l increase) to predict future CHF was 6.7 (95% confidence interval, 3.6–12.5; p < 0.001). The median time to CHF for dogs with NT-proANP levels >1000 pmol/l was 11 months (95% confidence interval, 5.6–12.6 months), compared to 54 months (46 – infinity) for dogs with concentrations ≤1000 pmol/l (p < 0.001). Due to intra- and inter-individual variability, most corresponding analyses for NOx were insignificant but dogs reaching CHF had a lower mean NOx concentration than dogs not reaching CHF (23 vs. 28 μmol/l, p = 0.016). Risk of CHF increased with increase in heart rate (>130 beats per minute) and grade of murmur (≥3/6).ConclusionsThe risk of CHF due to mitral regurgitation is increased in dogs with blood NT-proANP concentrations above 1000 pmol/l. Measurement of NT-proANP can be a valuable tool to identify dogs that may develop CHF within months.     

A single-cohort retrospective analysis of factors associated with morbidity and mortality in 193 anesthetized domestic goats

ObjectiveTo define the morbidity and mortality rates in goats undergoing general anesthesia at a large animal teaching hospital.Study designRetrospective, single-cohort, observational study.AnimalsRecords of 193 client-owned goats.MethodsData were collected from 218 medical records on 193 goats undergoing general anesthesia between January 2017 and December 2021. Demographic data, anesthetic management, recovery period and perianesthetic complications were recorded. Perianesthetic death was defined as anesthesia-related or anesthesia-contributory death occurring within 72 hours after recovery. Records of goats that were euthanized were reviewed to ascertain the cause of euthanasia. Each explanatory variable was individually investigated by univariable penalized maximum likelihood logistic regression, followed by multivariable analysis. Statistical significance was set at p < 0.05.ResultsPerianesthetic mortality was 7.3%, but was 3.4% when considering only goats undergoing elective procedures. Multivariable analysis showed that gastrointestinal surgeries [odds ratio (OR) 19.17, standard error (SE) 12.99, 95% confidence interval (CI) 5.08–72.33; p < 0.01] and requirement for perianesthetic norepinephrine infusion (OR 10.85, SE 8.82, 95% CI 2.21–53.33; p < 0.01) were associated with increased mortality. Maintaining other variables equal, the use of perianesthetic ketamine infusion was associated with decreased mortality (OR 0.09, SE 0.09, 95% CI 0.01–0.73; p = 0.02). Anesthesia-related or anesthesia-contributory complications included hypothermia (52.4%), bradycardia (38.1%), hypotension (35.3%), hypoxemia (14.8%), regurgitation/aspiration (7.3%), azotemia/acute renal failure (4.6%), myopathies/neuropathies (4.1%) and fever of unknown origin (2.7%).Conclusions and clinical relevanceIn this population, gastrointestinal surgeries and the requirement for perianesthetic norepinephrine infusion were associated with increased mortality in goats undergoing general anesthesia, while ketamine infusion may have a protective effect.     

Use of pimobendan in 170 cats (2006–2010)

Hypothesis/ObjectivesTo describe the therapeutic use of pimobendan in cats, describe the patient population to which it was administered, document potential side effects and report the clinical course following administration of pimobendan in conjunction with standard heart failure therapy. It is hypothesized that cats with advanced heart disease including congestive heart failure from a variety of causes will tolerate pimobendan with a minimum of side effects when used in treatment in conjunction with a variety of other medications.Animals, materials and methodsOne hundred and seventy client owned cats with naturally occurring heart disease, one hundred and sixty four of which had congestive heart failure. Medical records were reviewed and owners and referring veterinarians were contacted for follow-up data. Data collected included pimobendan dose, other medications administered concurrently, data collected at physical examination, presence or absence of heart failure, adverse effects, classification of heart disease, echocardiographic data and survival time. The data were analyzed for significance between the initial visit and any follow-up visits.ResultsAll cats were treated with pimobendan. The median pimobendan dose was 0.24 mg/kg q 12 h. Pimobendan was used in combination with multiple concurrent medications including angiotensin converting enzyme inhibitors, diuretics and anti-thrombotics. Five cats (3.0%) had potential side effects associated with pimobendan. One cat (0.6%) had presumed side effects severe enough to discontinue pimobendan use. Median survival time for 164 cats with congestive heart failure after initiation of pimobendan was 151 days (range 1–870).ConclusionPimobendan appears to be well tolerated in cats with advanced heart disease when used with a variety of concurrent medications. Randomized controlled studies need to be performed to accurately assess whether it is efficacious for treatment of congestive heart failure in cats.     

The influence of demeanor on scores from two validated feline pain assessment scales during the perioperative period

ObjectiveTo evaluate the effects of demeanor on validated pain assessment scales.Study designProspective, blind, clinical trial.Animal populationThirty three adult domestic cats scheduled for orchiectomy.MethodsCats were assessed for pain pre (baseline) and 1, 2, 4 hours postoperatively using two validated pain scales [Composite Measures Pain Scale-Feline (rCMPS-F) and UNESP-Botucatu multidimensional composite pain scale (psychomotor and pain expression subscales; U-B MCPS-psych and -painex)], and a demeanor scale. Return of sternal recumbency and postoperative feeding were recorded. Anesthesia consisted of a single intramuscular injection of dexmedetomidine-ketamine-hydromorphone with intratesticular lidocaine and atipamezole and meloxicam postoperatively. Following data collection, cats were assigned to two groups based on baseline demeanor scores (LO ≤ 5/21, 18 cats; HI ≥ 6/21, 15 cats) and data from each group compared.ResultsBaseline demeanor predicted pain scores with the U-B MCPS-psych scale: baseline [LO 0 (0–0), HI 2 (0–6), p = 0.0005], 1 hour [LO 1 (0–5), HI 3 (1–5), p = 0.02], and 4 hours [LO 0 (0–2), HI 1 (0–6), p = 0.01]. A similar pattern was observed with the rCMPS-F. This resulted in more crossings of the analgesic intervention threshold in the HI group: U-B UNESP-psych (9 versus 1, p = 0.005) and rCMPS-F (23 versus 3, p < 0.0001). In contrast, U-B MCPS-painex scores did not differ between LO/HI groups: baseline (p > 0.99), 1 hour (p = 0.34), 2 hours (p > 0.99) and 4 hours (p = 0.31). LO cats ate sooner (61% versus 33% by 1 hour, p < 0.0001) despite similar times to sternal recumbency (p = 0.48).Conclusions and clinical relevanceDemeanor affected pain assessment with U-B UNESP-psych and rCMPS-F scales, but not U-B UNESP-painex scale. Demeanor had a significant effect on postoperative feeding. These data highlight the potential for demeanor to confound pain assessment.     

Effect of benazepril and pimobendan on serum angiotensin‐converting enzyme activity in dogs

To support their combined use, the objective of the study was to evaluate the effects of benazepril and pimobendan on serum angiotensin‐converting enzyme (ACE) activity in dogs. A total of 48 healthy beagle dogs were randomized into four groups (n = 12 per group) in a parallel‐group design study: A (control, placebo twice daily (BID)); B (0.5–1.0 mg/kg benazepril once daily (SID) in the morning, placebo in the evening); C (0.25–0.5 mg/kg benazepril BID); D (0.25–0.5 mg/kg benazepril and 0.125–0.25 mg/kg pimobendan, both BID). The test items were administered orally for 15 days. Serum ACE activity was measured on days 1 and 15. Groups B, C and D had significantly lower average serum ACE activity compared to baseline and to the control group, on both days 1 and 15. There were no significant differences in average ACE activity between groups B, C and D. Noninferiority of group C to B was demonstrated. In conclusion, 0.25–0.5 mg/kg benazepril administered BID produced noninferior inhibition of serum ACE activity compared to 0.5–1.0 mg/kg benazepril dosed SID. Pimobendan had no significant effect on benazepril's action on serum ACE activity. The results support the use of benazepril BID in dogs and in combination with pimobendan.     

Prediction of first onset of congestive heart failure in dogs with degenerative mitral valve disease: The PREDICT cohort study

ObjectiveTo identify risk factors for first-onset congestive heart failure (CHF) in dogs with degenerative mitral valve disease (DMVD).AnimalsEighty-two dogs with and without CHF secondary to DMVD were retrospectively assigned to a derivation cohort. Sixty-five dogs with asymptomatic DMVD were recruited into a prospective validation cohort.MethodsVariables associated with risk of CHF in dogs were identified in a derivation cohort and used to construct a predictive model, which was then prospectively tested through longitudinal examination of a validation cohort.ResultsLogistic regression analysis of the derivation cohort yielded a predictive model that included the left atrial to aortic root dimension ratio (LA:Ao) and plasma concentration of N-terminal pro-B-type natriuretic peptide (NT-proBNP). When this model was prospectively applied to the validation cohort, it correctly predicted first-onset of CHF in 69.2% of cases. Analysis of the validation cohort revealed that plasma NT-proBNP concentration and indexed left ventricular end-diastolic diameter (LVIDd:Ao) were independent risk factors for development of first-onset CHF in dogs with DMVD (NT-proBNP ≥1500 pmol/L, odds ratio (OR), 5.76, 95% confidence interval (CI), 1.37–24.28, P = 0.017; LVIDd:Ao ≥3, OR, 6.11, 95% CI, 1.09–34.05, P = 0.039).ConclusionsMeasures of left heart size and plasma NT-proBNP concentration independently estimate risk of first-onset of CHF in dogs with DMVD. These parameters can contribute to the management of dogs with DMVD.     

Comparison between dexmedetomidine and acepromazine in combination with methadone for premedication in brachycephalic dogs undergoing surgery for brachycephalic obstructive airway syndrome

ObjectiveTo compare dexmedetomidine with acepromazine for premedication combined with methadone in dogs undergoing brachycephalic obstructive airway syndrome (BOAS) surgery.Study designRandomized, blinded clinical study.AnimalsA group of 40 dogs weighing mean (± standard deviation) 10.5 ± 6 kg, aged 2.6 ± 1.9 years.MethodsDogs received either acepromazine 20 μg kg^–1 (group A) or dexmedetomidine 2 μg kg^–1 (group D) intramuscularly with methadone 0.3 mg kg^–1. Anaesthesia was induced with propofol and maintained with sevoflurane. Sedation (0–18), induction (0–6) and recovery (0–5) qualities were scored. Propofol dose, hypotension incidence, mechanical ventilation requirement, extubation time, additional sedation, oxygen supplementation, regurgitation and emergency intubation following premedication or during recovery were recorded. Data were analysed using t tests, Mann-Whitney U or Chi-square tests.ResultsGroup A dogs were less sedated [median (range): 1.5 (0–12)] than group D [5 (1–18)] (p = 0.021) and required more propofol [3.5 (1–7) versus 2.4 (1–8) mg kg^–1; p = 0.018]. Induction scores [group A: 5 (4–5); group D 5 (3–5)] (p = 0.989), recovery scores [group A 5 (4–5); group D 5(3–5)](p = 0.738) and anaesthesia duration [group A:93 (50–170); group D 96 (54–263) minutes] (p = 0.758) were similar between groups. Time to extubation was longer in group A 12.5 (3-35) versus group D 5.5 (0–15) minutes; (p = 0.005). During recovery, two dogs required emergency intubation (p > 0.99) and five dogs required additional sedation (p > 0.99). Oxygen supplementation was required in 16 and 12 dogs in group A and D, respectively (p = 0.167); no dogs in group A and one dog in group D regurgitated (p = 0.311).Conclusions and clinical relevanceDexmedetomidine 2 μg kg^–1 produces more sedation but similar recovery quality to acepromazine 20 μg kg^–1 combined with methadone in dogs undergoing BOAS surgery.     

Effect of intravenous fentanyl on cough reflex and quality of endotracheal intubation in cats

ObjectiveTo assess the effects of intravenous (IV) fentanyl on cough reflex and quality of endotracheal intubation (ETI) in cats.Study designRandomized, blinded, negative controlled clinical trial.AnimalsA total of 30 client-owned cats undergoing general anaesthesia for diagnostic or surgical procedures.MethodsCats were sedated with dexmedetomidine (2 μg kg^–1 IV), and 5 minutes later either fentanyl (3 μg kg^–1, group F) or saline (group C) was administered IV. After alfaxalone (1.5 mg kg^–1 IV) administration and 2% lidocaine application to the larynx, ETI was attempted. If unsuccessful, alfaxalone (1 mg kg^–1 IV) was administered and ETI re-attempted. This process was repeated until successful ETI. Sedation scores, total number of ETI attempts, cough reflex, laryngeal response and quality of ETI were scored. Postinduction apnoea was recorded. Heart rate (HR) was continuously recorded and oscillometric arterial blood pressure (ABP) was measured every minute. Changes (Δ) in HR and ABP between pre-intubation and intubation were calculated. Groups were compared using univariate analysis. Statistical significance was set as p < 0.05.ResultsThe median and 95% confidence interval of alfaxalone dose was 1.5 (1.5–1.5) and 2.5 (1.5–2.5) mg kg^–1 in groups F and C, respectively (p = 0.001). The cough reflex was 2.10 (1.10–4.41) times more likely to occur in group C. The overall quality of ETI was superior in group F (p = 0.001), with lower laryngeal response to ETI (p < 0.0001) and ETI attempts (p = 0.045). No differences in HR, ABP and postinduction apnoea were found.Conclusions and clinical relevanceIn cats sedated with dexmedetomidine, fentanyl could be considered to reduce the alfaxalone induction dose, cough reflex and laryngeal response to ETI and to improve the overall quality of ETI.     

A comparison of the pharmacodynamic effects of intravenous ketamine–xylazine with alfaxalone in mute swans (Cygnus olor) presenting at a wildlife veterinary hospital

ObjectiveTo compare effects of intravenous (IV) alfaxalone with ketamine–xylazine combination on anaesthetic induction, recovery and cardiopulmonary variables in mute swans.Study designRandomized, controlled, clinical study.AnimalsA group of 58 mute swans.MethodsSwans were given either alfaxalone (10 mg kg^–1; group A) or a combination of ketamine (12.5 mg kg^–1) and xylazine (0.28 mg kg^–1) (group KX) IV. Heart and respiratory rates, end-tidal carbon dioxide and peripheral haemoglobin oxygen saturation were recorded at 5 minute intervals during anaesthesia. Time from anaesthetic induction to intubation, from cessation of isoflurane to extubation, to lifting head, sternal recumbency and absence of head/neck ataxia were recorded. Anaesthetic and recovery quality were scored (1 = very poor; 5 = excellent). Data are presented as median (interquartile range). Significance was set at p < 0.05.ResultsIn group A, 44% (12/27) of swans required mechanical ventilation for 2–14 minutes versus 3.2% (1/31) of swans in group KX (p = 0.0002). Heart rate was higher in group A than in group KX [146 (127–168) versus 65.5 (56–78) beats minute^–1, respectively; p < 0.0001]. The isoflurane concentration required to maintain anaesthesia was higher in group A than in group KX [2.5% (2.0–3.0%) versus 1.5% (1.0–2.0%), respectively; p = 0.0001]. Time from cessation of isoflurane administration to lifting head was significantly longer in group A than in group KX [12 (9–17) versus 6 (4–7.75) minutes, respectively; p < 0.0001]. Anaesthesia quality scores were significantly better in group KX than in group A [4 (4–5) versus 4 (3–4), respectively; p = 0.0011], as were recovery scores [4 (3–5) versus 2 (2–3), respectively; p = 0.0005].Conclusions and clinical relevanceAlfaxalone is a suitable anaesthetic induction agent for use in mute swans. There is a greater incidence of postinduction apnoea and a higher incidence of agitation on recovery with alfaxalone than with ketamine–xylazine.     

Effects of fentanyl–lidocaine–ketamine versus sufentanil–lidocaine–ketamine on the isoflurane requirements in dogs undergoing total ear canal ablation and lateral bulla osteotomy

ObjectiveTo compare the isoflurane-sparing effects of sufentanil–lidocaine–ketamine (SLK) and fentanyl–lidocaine–ketamine (FLK) infusions in dogs undergoing total ear canal ablation and lateral bulla osteotomy (TECA–LBO).Study designRandomized blinded clinical study.AnimalsA group of 20 client-owned dogs undergoing TECA–LBO.MethodsIntravenous (IV) administration of lidocaine (3 mg kg^–1) and ketamine (0.6 mg kg^–1) with fentanyl (5.4 μg kg^–1; n = 10; FLK group) or sufentanil (0.72 μg kg^–1; n = 10; SLK group) was immediately followed by the corresponding constant rate infusion (CRI) (lidocaine 3 mg kg^–1 hour^–1; ketamine 0.6 mg kg^–1 hour^–1; either fentanyl 5.4 μg kg^–1 hour^–1 or sufentanil 0.72 μg kg^–1 hour^–1). Anaesthesia was induced with propofol 3–5 mg kg^–1 IV and was maintained with isoflurane. End-tidal isoflurane concentration (Fe′Iso) was decreased in 0.2% steps every 15 minutes until spontaneous movements were observed (treated with propofol 1 mg kg^–1 IV) or an increase of > 30% in heart rate or mean arterial pressure from baseline occurred (treated with rescue fentanyl or sufentanil). Quality of recovery and pain were assessed at extubation using the short-form Glasgow Composite Pain Scale (SF-GCPS), Colorado State University Canine Acute Pain scale (CSU-CAP), and visual analogue scale (VAS). Data were analysed with analysis of variance, t tests, Fisher test and Spearman coefficient (p < 0.05).ResultsFe′Iso decreased significantly in SLK group (45%; p = 0.0006) but not in FLK (15%; p = 0.1135) (p = 0.0136). SLK group had lower scores for recovery quality (p = 0.0204), SF-GCPS (p = 0.0071) and CSU-CAP (p = 0.0273) than FLK at extubation. Intraoperative rescue analgesia and VAS were not significantly different between groups.Conclusions and clinical relevanceCompared with FLK infusion, CRI of SLK at these doses decreased isoflurane requirements, decreased pain scores and improved recovery quality at extubation in dogs undergoing TECA–LBO.     

Association of QRS duration and survival in dogs with dilated cardiomyopathy: A retrospective study of 266 clinical cases

ObjectiveThe purpose of this study was to investigate the prognostic value of QRS duration in dogs with dilated cardiomyopathy (DCM) by studying its relationship with survival time.MethodsThe medical records of dogs diagnosed with DCM were retrospectively searched for good quality ECG tracings. The QRS duration was measured from the ECG tracing and two different models were used: binary variable (dogs were divided into 2 groups based on a QRS duration of <60 ms or ≥60 ms) and continuous variable. The survival times were analysed by the Kaplan-Meier method and Cox’s proportional hazard model.Results266 dogs met the inclusion and exclusion criteria. A QRS duration ≥60 ms was associated with a reduced survival time compared to those with a QRS duration <60 ms (Hazard Ratio of 1.34, 95% CI 1.05–1.71, P = 0.02). When considered as a continuous variable the Hazard Ratio was 1.015 for each increase in QRS duration of 1 ms (95% CI 1.006–1.024, p = 0.001).Dogs with a QRS duration < 60 ms had a median survival time (IQ range) of 25 weeks (97-65) and dogs with a QRS duration ≥60 ms had a median survival time (IQ range) of 13 weeks (3–34).ConclusionThe measurement of QRS duration is relatively simple to perform from a surface ECG recording. A duration ≥60 ms is associated with shorter survival times in dogs with DCM, which may provide practitioners with additional prognostic information.