Anesthetic effects of the ketamine and midazolam association by intranasal or intramuscular route in domestic chickens: prospective, blinded, randomized and crossover study.

This prospective, blinded, randomized crossover study aimed to assess the anesthetic effects of the combination of 30 mg/kg ketamine and 2 mg/kg midazolam via intranasal (IN) or intramuscular (IM) routes in twelve domestic chickens. Physiological parameters (respiratory rate - RR, heart rate - HR, and cloacal temperature -Tºcloacal) were monitored throughout the experiment, along with recovery time and sedation level (S0: awake, no recumbency, responsive to stimuli; S1: blinking eyes, recumbency, relaxed, response to stimulus, mild movement; S2: open eyes, recumbency, relaxed, mild response to stimuli; S3: closed eyes, recumbency, relaxed, no movement). In the IM group, all birds reached S3, while in IN 5/12 reached S3, 4/12 reached at most S1, and 1/12 at most S2. IM administration showed higher sedation at 5, 10, 15, 20, 30, 35, 40, and 45 minutes (p<0.05). IN administration exhibited a shorter total recovery time (26.3±21.4 min vs. 92.9±33.4 min; p<0.001). No time, group, or time-group interaction effects were observed in HR and cloacal Tº, with a trend to a decrease in RR both groups (p<0.001). Increased incidences of vocalization and agitation was observed via IM (4/12 vs. 0/12; p=0.028), with no difference in salivation. Despite faster recovery with less agitation and vocalization, the ketamine and midazolam combination via IN provided less consistent sedation compared to the IM route in chickens.

Este estudo crossover randomizado objetivou avaliar os efeitos anestésicos da associação de 30 mg/kg de cetamina e 2 mg/kg de midazolam via intranasal (IN) ou intramuscular (IM) em doze galinhas. Além dos parâmetros fisiológicos (frequência respiratória ­ FR e cardíaca ­ FC e temperatura cloacal ­ Tºcloacal), registrou-se o tempo de recuperação e o grau de sedação ao longo do experimento (S0: acordada, sem decúbito, responsiva a estímulos; S1: olhos piscando, decúbito, relaxada, resposta a estímulo, movimentação leve; S2: olhos abertos, decúbito, relaxada, resposta leve a estímulos; S3: olhos fechados, decúbito, relaxada, sem movimentação. Pela via IM, todas as aves atingiram o grau S3, enquanto pela via IN 5/12 alcançaram S3, 4/12 atingiram no máximo S1 e 1/12 no máximo S2. A via IM apresentou maior sedação em 5, 10, 15, 20, 30, 35, 40 e 45 min (p<0,05). A via IN apresentou menor tempo total até recuperação (26,3±21,4 min vs. 92,9±33,4 min; p<0,001). Não foram observados efeitos de tempo, grupo e interação tempo-grupo na FC e na Tºcloacal com uma tendência de queda da FR nos dois grupos (p<0,001). Observou-se maior incidência de vocalização e agitação pela via IM (4/12 vs. 0/12; p=0,028), não havendo diferença para sialorreia. Apesar da recuperação mais rápida e com menos agitação e vocalização, a associação cetamina e midazolam via IN levou a uma sedação menos consistente que a via IM em galinhas.

Cervical ultrasound for endotracheal intubation confirmation in dogs by veterinary students: a cadaveric study.

Although endotracheal intubation is usually a simple and fast procedure in dogs, some situations can be challenging and lead to the risk of tube misplacement in the esophagus-a life-threatening complication. Hence, confirming intubation is a cornerstone whenever this procedure is performed. Methods such as direct visualization or capnography present limitations insofar as they may be unreliable or unavailable under some circumstances. Ultrasound has emerged as a promising tool to confirm intubation in medicine. However, so far little research has been done on the subject in veterinary medicine. This study's main goal was to investigate ultrasound performed by veterinary students as a confirmation method for intubation in canine cadavers after a brief training session (25 minutes). A total of 160 exams were performed with a microconvex probe by 20 students in 11 different cadavers on left and right recumbencies. Overall accuracy was 70.6% with a median success rate of 75% and a median time to diagnosis of 25 seconds. The number of correct diagnoses was statistically higher than the wrong ones (p<0.05) without difference between recumbencies. Sensitivity, specificity, and positive and negative predictive values were 72.5%, 68.8%, 69.9%, and 71.4%, respectively. The fastest diagnosis was performed in just 4 seconds, and among the top-performers, one student had 100% accuracy with a mean time to diagnosis of 16.8 seconds, and four students had approximately 88% accuracy. This study showed for the first time that even inexperienced veterinary students can have acceptable accuracy in confirming endotracheal intubation in dogs after a brief training session.

Apesar de a intubação endotraqueal em cães ser frequentemente um procedimento simples e rápido, algumas situações podem ser desafiadoras e levar ao risco de posicionamento da sonda no esôfago - uma grave complicação. Portanto, a confirmação da intubação é uma etapa crucial sempre que o procedimento for realizado. Métodos como visualização direta ou capnografia apresentam limitações e podem ser pouco confiáveis ou indisponíveis sob certas circunstâncias. A ultrassonografia surgiu como uma ferramenta promissora para confirmação da intubação na medicina. Contudo, até o momento pouco foi estudado na veterinária. O objetivo deste estudo foi investigar a ultrassonografia realizada por estudantes de veterinária como método de confirmação para a intubação em cadáveres caninos após um breve treinamento (25 minutos). Foram realizados 160 exames com transdutor microconvexo por 20 estudantes em 11 cadáveres nos decúbitos direito e esquerdo. A acurácia geral foi 70.6% com medianas de taxa de sucesso de 75% e de tempo para diagnóstico de 25 segundos. O número de diagnósticos corretos foi estatisticamente superior aos errados (p<0.05) sem diferença entre decúbitos. Sensibilidade, especificidade, valor preditivo positivo e negativo foram, respectivamente: 72.5%; 68.8%; 69.9% e 71.4%. O diagnóstico mais rápido se deu em 4 segundos e entre os estudantes com melhor performance, um se destacou com 100% de acurácia e tempo médio para diagnóstico de 16.8 segundos enquanto quatro outros obtiveram 88% de acurácia. Este estudo demonstrou pela primeira vez que mesmo estudantes de veterinária inexperientes podem atingir uma acurácia aceitável na confirmação da intubação endotraqueal em cães após um breve treinamento.

Fluid management strategies and their interaction with mechanical ventilation: from experimental studies to clinical practice.

Patients on mechanical ventilation may receive intravenous fluids via restrictive or liberal fluid management. A clear and objective differentiation between restrictive and liberal fluid management strategies is lacking in the literature. The liberal approach has been described as involving fluid rates ranging from 1.2 to 12 times higher than the restrictive approach. A restrictive fluid management may lead to hypoperfusion and distal organ damage, and a liberal fluid strategy may result in endothelial shear stress and glycocalyx damage, cardiovascular complications, lung edema, and distal organ dysfunction. The association between fluid and mechanical ventilation strategies and how they interact toward ventilator-induced lung injury (VILI) could potentiate the damage. For instance, the combination of a liberal fluids and pressure-support ventilation, but not pressure control ventilation, may lead to further lung damage in experimental models of acute lung injury. Moreover, under liberal fluid management, the application of high positive end-expiratory pressure (PEEP) or an abrupt decrease in PEEP yielded higher endothelial cell damage in the lungs. Nevertheless, the translational aspects of these findings are scarce. The aim of this narrative review is to provide better understanding of the interaction between different fluid and ventilation strategies and how these interactions may affect lung and distal organs. The weaning phase of mechanical ventilation and the deresuscitation phase are not explored in this review.

Effects of different fluid management on lung and kidney during pressure-controlled and pressure-support ventilation in experimental acute lung injury.

Optimal fluid management is critical during mechanical ventilation to mitigate lung damage. Under normovolemia and protective ventilation, pulmonary tensile stress during pressure-support ventilation (PSV) results in comparable lung protection to compressive stress during pressure-controlled ventilation (PCV) in experimental acute lung injury (ALI). It is not yet known whether tensile stress can lead to comparable protection to compressive stress in ALI under a liberal fluid strategy (LF). A conservative fluid strategy (CF) was compared with LF during PSV and PCV on lungs and kidneys in an established model of ALI. Twenty-eight male Wistar rats received endotoxin intratracheally. After 24 h, they were treated with CF (minimum volume of Ringer's lactate to maintain normovolemia and mean arterial pressure ≥70 mmHg) or LF (~4 times higher than CF) combined with PSV or PCV (VT  = 6 ml/kg, PEEP = 3 cmH2 O) for 1 h. Nonventilated animals (n = 4) were used for molecular biology analyses. CF-PSV compared with LF-PSV: (1) decreased the diffuse alveolar damage score (10 [7.8-12] vs. 25 [23-31.5], p = 0.006), mainly due to edema in axial and alveolar parenchyma; (2) increased birefringence for occludin and claudin-4 in lung tissue and expression of zonula-occludens-1 and metalloproteinase-9 in lung. LF compared with CF reduced neutrophil gelatinase-associated lipocalin and interleukin-6 expression in the kidneys in PSV and PCV. In conclusion, CF compared with LF combined with PSV yielded less lung epithelial cell damage in the current model of ALI. However, LF compared with CF resulted in less kidney injury markers, regardless of the ventilatory strategy.