Effects of oxygen supplementation in ewes subjected to laparoscopic ovum pick-up under total intravenous anesthesia / Efeitos da suplementação de oxigênio em ovelhas submetidas à aspiração de folículos por laparoscopia sob anestesia intravenosa total

Laparoscopy procedures are useful tools to perform some assisted reproductive biotechnologies in ewes, it requi-res general anesthesia and manoeuvres that might result in alteration of the cardiopulmonary function. For this reason, this study aimed to investigate the effects of oxygen supplementation as a therapeutic measure to mitigate these alterations in ewes submitted to laparoscopic ovum pick-up (LOPU) under total intravenous anesthesia (TIVA). Twenty-four healthy adult ewes were submitted to two LOPUs with a 21 days interval, under ketamine-midazolam anesthesia, and receiving each of the two experimental in random order, oxygen treatment (OT) 50 mL/kg/min of oxygen via endotracheal tube and control treatment (CT) not receive any inhalation treatment. Heart rate (HR), respiratory rate (fR), peripheral oxygen saturation (SpO2), mean arterial pressure (MAP), rectal temperature (RT), end-tidal CO2 concentration (EtCO2) and recovery anesthesia time were evaluated during LOPU, arterial blood gases and electrolytes were evaluated after induction of anesthesia and at the end of the LOPU. Variables were compared between groups and moments using ANOVA. MAP, SpO2, PaO2, SaO2 and pH were higher in OT, while EtCO2, PaCO2, temperature loss and recovery time were lower. These results allow to conclude that oxy-gen supplementation in ewes submitted to LOPU under TIVA provides benefits in order to mitigate physiological alterations.(AU)

Os procedimentos de laparoscopia são ferramentas úteis para realizar algumas biotecnologias de reprodução assistida em ovelhas, requer anestesia geral e manobras que podem resultar em alteração da função cardiopulmonar. Por esse motivo, este estudo teve como objetivo investigar os efeitos da suplementação de oxigênio como medida terapêutica para atenuar as alterações em ovelhas submetidas à Aspiração Folicular guiada por Laparoscopia (LOPU) sob anestesia venosa total (TIVA). Vinte e quatro ovelhas adultas saudáveis foram submetidas a duas LOPUs com intervalo de 21 dias, sob anestesia com cetamina-midazolam, recebendo cada um dos dois experimentos em ordem aleatória, tratamento com oxigênio (OT) 50 mL/kg/min de oxigênio via tubo endotraqueal e tratamento de controle (CT) não recebem nenhum tratamento por inalação. Frequência cardíaca (FC), frequência respiratória (FR), saturação periférica de oxigênio (SpO2), pressão arterial média (PAM), temperatura retal (TR), concentração expirada de CO2 (EtCO2) e tempo de recuperação da anestesia foram avaliados durante LOPU, arterial gasometria e eletrólitos foram avaliados após a indução da anestesia e ao final da COL. As variáveis foram comparadas entre grupos e momentos por meio de ANOVA. PAM, SpO2, PaO2, SaO2 e pH foram maiores no TO, enquanto EtCO2, PaCO2, perda de temperatura e tempo de recuperação foram menores. Estes resultados permitem concluir que a suplementação de oxigênio em ovelhas submetidas a LOPU sob TIVA proporciona benefícios no sentido de atenuar as alterações fisiológicas.(AU)

Oxygen supply as a refining technique for injectable anesthesia in laboratory rats

Well-controlled anesthesia is critical to reducing potential surgical complications and ensuring safe and successful procedures. Respiratory depression, inducing hypoxia, and hypercapnia are adverse effects of injectable anesthesia in laboratory rats. This study aimed to determine the effect of oxygen supply in laboratory rats anesthetized with the combination of ketamine (K) and xylazine (X) plus acepromazine (A) or methadone (Me). The results showed that oxygenation allowed adequate levels of SO2 and paO2, avoiding hypoxemia. However, all anesthetized rats showed respiratory acidosis with low pH and high paCO2 levels, which was not reversed after oxygen administration. The acidosis could be related to hypoventilation due to respiratory depression induced by the XKMe association, as well as absorption atelectasis with the CO2 accumulation during anesthesia. Despite respiratory acidosis, oxygen administration was beneficial for anesthetized rats preventing hypoxemia. This makes it possible to prevent all the metabolic alterations that cause cell death by hypoxia, improving the well-being of anesthetized rats, as well as the quality of the results obtained.

Manejo de neonatos caninos prematuros / Management of premature neonatal puppies

Dentre as mais importantes causas de morbidade neonatal na prematuridade, destacam-se os distúrbios respiratórios, complicações infecciosas, instabilidade crítica da termorregulação, inabilidade para homeostase energética e falhas na transferência de imunidade passiva. Dentre os problemas de origem pulmonar intimamente relacionados à prematuridade, destaca-se a imaturidade pulmonar por deficiência de surfactante, evoluindo para diminuição da capacidade pulmonar, hipoxemia, hipercapnia e acidose. Os neonatos caninos prematuros apresentam baixa vitalidade, hipotermia, bradipnéia, irregularidade do padrão respiratório, reduzido tônus e responsividade neuro-muscular. As áreas do parênquima pulmonar para efetuar trocas gasosas são limitadas em filhotes prematuros, culminando em alterações do equilíbrio ácidobase. Além disto, os recém-nascidos prematuros apresentam instabilidade energética e falha de transferência de imunidade passiva. Como medida preventiva à morbidade do neonato prematuro, indicase a corticoterapia pré-natal 48 horas antes do parto em cadelas gestantes, induzindo a maturidade funcional do pulmão fetal, além de melhorar a vitalidade e evolução clínica neonatal. Ademais, a corticoterapia antenatal estimula a transferência placentária de imunoglobulinas e absorção de imunoglobulinas colostrais, bem como aumenta a capacidade glicogênica. Nos casos emergenciais, preconiza-se medidas intensivas aos recém-nascidos prematuros, as quais incluem: reanimação respiratória, controle da hipotermia, reposição glicêmica na hipoglicemia e controle imunológico da falha de transferência imune passiva.(AU)

Among the most important causes of neonatal morbidity in prematurity, respiratory disorders, infectious complications, critical instability of thermoregulation, inability for energy homeostasis and failures in the transfer of passive immunity stand out. Among the problems of pulmonary origin closely related to prematurity, pulmonary immaturity due to surfactant deficiency stands out, evolving to decreased lung capacity, hypoxemia, hypercapnia and acidosis. Premature canine neonates have low vitality, hypothermia, bradypnea, irregular breathing pattern, reduced tone and neuromuscular responsiveness. The areas of the lung parenchyma to carry out gas exchange are limited in premature pups, culminating in changes in acid-base balance. In addition, premature newborns have energetic instability and failure to transfer passive immunity. As a preventive measure against premature neonate morbidity, prenatal corticosteroid therapy is indicated 48 hours before delivery in pregnant bitches, inducing functional maturity of the fetal lung, in addition to improving neonatal vitality and clinical evolution. Furthermore, antenatal corticosteroid therapy stimulates the placental transfer of immunoglobulins and the absorption of colostral immunoglobulins, as well as increasing the glycogenic capacity. In emergency cases, intensive measures are recommended for premature newborns, which include: respiratory resuscitation, hypothermia control, glycemic replacement in hypoglycemia and immunological control of passive immune transfer failure.(AU)

Anestesia geral em jabuti-piranga (Chelonoides carbonaria) para retirada de corpo estranho gástrico / General anesthesia in red-footed tortoise (Chelonoides carbonaria) for gastric foreign body removal

Background: The anatomical, physiological, and pharmacological characteristics of reptiles make anesthesia in chelonians particularly challenging. Specific literature regarding safe anesthetic protocols that provide immobilization, antinociception, amnesia, and unconsciousness are scarce. Thus, this paper aims to report the case of a red-footed tortoise submitted to long-duration general anesthesia to celiotomy for foreign body removal. Case: An adult red-footed tortoise (Chelonoides carbonaria), 5.9 kg, was admitted due to hyporexia after ingesting a metallic fishhook. Serial radiographs confirmed the diagnosis and location of the foreign body in the stomach. The animal was premedicated with 0.03 mg/kg dexmedetomidine, 6 mg/kg ketamine, and 0.4 mg/kg butorphanol intramuscularly. After 90 min we inserted a 22G jugular catheter and proceeded to anesthesia induction with 5 mg/kg propofol. We intubated the animal with a 2.5 mm uncuffed endotracheal and started fluid therapy at a rate of 5 mL/kg/h. Surgical anesthesia was maintained with isoflurane in 0.21 oxygen, in a non-rebreathing circuit (baraka), under spontaneous breathing. Expired isoflurane was maintained between 3 and 4.5%. Due to reduced respiratory rate and hypercapnia, we opted for implementing manually-assisted positive pressure ventilation. Morphine (0.5 mg/kg) was administered at 10 and 87 min after the beginning of the surgery for further analgesia when the isoflurane requirement increased significantly. We did not detect any alterations in heart and body temperature. Surgical anesthesia lasted 6 h. During anesthesia recovery, voluntary head retraction and coordinated movement of the limbs occurred at 240 and 540 min after the extubation, respectively. In 2 days, the patient returned to voluntary feeding, being very active and responsive to stimulus. The post-surgical hematologic evaluation was unremarkable. Discussion: Pre-anesthetic medication aimed to promote sedation and preemptive analgesia. Due to its minimal cardiorespiratory depression, we chose the combination of ketamine, dexmedetomidine, and butorphanol. Dexmedetomidine reduced the ketamine dose and caused sufficient muscle relaxation and immobilization to perform the jugular catheter placement. Butorphanol is an agonist-antagonist opioid; that is why we decided to add it to the protocol for antinociception. However, due to signs of nociceptive response (increased isoflurane requirements and heart rate), and considering the evidence of a predominance of µ receptors in reptiles, we administered low-dose morphine twice during the procedure. Propofol was chosen as an induction agent at a dose sufficient to allow endotracheal intubation. Since reptilians often show apnea in the presence of 100% oxygen, we used a 0.21 oxygen fraction. Despite this, the patient showed respiratory depression. Due to right to left cardiac shunt, sudden changes in the direction of the blood can lead to very rapid changes in the serum concentrations of isoflurane, which leads to frequent oscillations in the anesthetic depth and consequently the need for vaporizer adjustments, which may justify the high expired isoflurane fraction during the procedure. Despite that, physiological parameters were maintained within normal ranges for the species, with slight variations during the surgical procedure. We conclude that the proposed anesthetic protocol is safe for long-duration anesthesia in chelonians, ensuring cardiovascular and respiratory stability. Thus, this report may help veterinarians to perform safe anesthesia in tortoises submitted to invasive surgical procedures.

Hypercapnia attenuates ventilator-induced lung injury through vagus nerve activation

Purpose:To investigate the role of vagus nerve activation in the protective effects of hypercapnia in ventilator-induced lung injury (VILI) rats.Methods:Male Sprague-Dawley rats were randomized to either high-tidal volume or low-tidal volume ventilation (control) and monitored for 4h. The high-tidal volume group was further divided into either a vagotomy or sham-operated group and each surgery group was further divided into two subgroups: normocapnia and hypercapnia. Injuries were assessed hourly through hemodynamics, respiratory mechanics and gas exchange. Protein concentration, cell count and cytokines (TNF-α and IL-8) in bronchoalveolar lavage fluid (BALF), lung wet-to-dry weight and pathological changes were examined. Vagus nerve activity was recorded for 1h.Results:Compared to the control group, injurious ventilation resulted in a decrease in PaO2/FiO2 and greater lung static compliance, MPO activity, enhanced BALF cytokines, protein concentration, cell count, and histology injury score. Conversely, hypercapnia significantly improved VILI by decreasing the above injury parameters. However, vagotomy abolished the protective effect of hypercapnia on VILI. In addition, hypercapnia enhanced efferent vagus nerve activity compared to normocapnia.Conclusion:These results indicate that the vagus nerve plays an important role in mediating the anti-inflammatory effect of hypercapnia on VILI.(AU)

Influência dos níveis de CO2 e do tipo de incubadora sobre o desempenho zootécnico e morfometria cardíaca de frangos de corte / Influence of CO2 levels and type of incubator on the performance of broilers

O objetivo do trabalho foi avaliar incubadoras de estágio múltiplo e único e diferentes níveis de CO2 sobre o desempenho, número e diâmetro das fibras musculares, morfometria cardíaca e rendimento de carcaça de frangos de corte. Foram incubados 2.520 ovos férteis em um delineamento inteiramente ao acaso, distribuídos em quatro níveis de CO2 (4.000, 6.000, 8.000 e 10.000ppm) em incubadoras de estágio único durante os primeiros dez dias de incubação e um tratamento controle utilizando uma incubadora de estágio múltiplo, totalizando cinco tratamentos com 504 ovos em cada um. Após a eclosão, 1.050 pintos machos foram alojados de acordo com o delineamento utilizado no incubatório. A hipercapnia aplicada nos primeiros 10 dias de incubação afetou o ganho de peso e a conversão alimentar dos pintos na primeira semana de vida, no entanto, esses efeitos não foram mantidos até o final do período de criação. Não houve efeito de incubadoras ou da hipercapnia sobre a morfometria muscular e cardíaca. Houve maior rendimento de coxas das aves na idade de abate oriundas de incubadoras em estágio único com até 6.000 ppm de CO2, quando comparadas à incubação em máquinas de estágio múltiplo. Esse efeito pode ser atribuído à maior vascularização induzida pela hipercapnia precoce.

The aim of this work was to assess single and multiple-stage incubators and different CO2 levels over performance, number and diameter of muscle fibers, cardiac morphometry and carcass yield of broilers. Two thousand five hundred and twenty fertile eggs were randomly allocated and distributed into four different CO2 levels (4,000, 6,000, 8,000 and 10,000ppm) during the first ten days of incubation. After hatchling, 1,050 male chicks were placed into an experimental barn following the design used in the hatchery. Induced hypercapnia during the first ten days affected weight gain and feed conversion ratio of one-week-old chicks. However, these aspects did not last until the end of the rearing period. There was no effect of either hatchers or hypercapnia on number and diameter of muscle fibers and cardiac morphometry. Higher thigh yield was noted in the birds from single-stage incubators up to 6,000ppm of CO2. This fact is explained through higher vascularization caused by premature hypercapnia.

Influência dos níveis de CO2 e do tipo de incubadora sobre o desempenho zootécnico e morfometria cardíaca de frangos de corte / Influence of CO2 levels and type of incubator on the performance of broilers

O objetivo do trabalho foi avaliar incubadoras de estágio múltiplo e único e diferentes níveis de CO2 sobre o desempenho, número e diâmetro das fibras musculares, morfometria cardíaca e rendimento de carcaça de frangos de corte. Foram incubados 2.520 ovos férteis em um delineamento inteiramente ao acaso, distribuídos em quatro níveis de CO2 (4.000, 6.000, 8.000 e 10.000ppm) em incubadoras de estágio único durante os primeiros dez dias de incubação e um tratamento controle utilizando uma incubadora de estágio múltiplo, totalizando cinco tratamentos com 504 ovos em cada um. Após a eclosão, 1.050 pintos machos foram alojados de acordo com o delineamento utilizado no incubatório. A hipercapnia aplicada nos primeiros 10 dias de incubação afetou o ganho de peso e a conversão alimentar dos pintos na primeira semana de vida, no entanto, esses efeitos não foram mantidos até o final do período de criação. Não houve efeito de incubadoras ou da hipercapnia sobre a morfometria muscular e cardíaca. Houve maior rendimento de coxas das aves na idade de abate oriundas de incubadoras em estágio único com até 6.000 ppm de CO2, quando comparadas à incubação em máquinas de estágio múltiplo. Esse efeito pode ser atribuído à maior vascularização induzida pela hipercapnia precoce.(AU)

The aim of this work was to assess single and multiple-stage incubators and different CO2 levels over performance, number and diameter of muscle fibers, cardiac morphometry and carcass yield of broilers. Two thousand five hundred and twenty fertile eggs were randomly allocated and distributed into four different CO2 levels (4,000, 6,000, 8,000 and 10,000ppm) during the first ten days of incubation. After hatchling, 1,050 male chicks were placed into an experimental barn following the design used in the hatchery. Induced hypercapnia during the first ten days affected weight gain and feed conversion ratio of one-week-old chicks. However, these aspects did not last until the end of the rearing period. There was no effect of either hatchers or hypercapnia on number and diameter of muscle fibers and cardiac morphometry. Higher thigh yield was noted in the birds from single-stage incubators up to 6,000ppm of CO2. This fact is explained through higher vascularization caused by premature hypercapnia.(AU)

Changes in arterial partial pressure and end-expired pressure of carbon dioxide in prepubescent and adult bitches undergoing ovariohysterectomy by videolaparoscopy or conventional laparotomy / Variações nas pressões parciais arteriais e expiradas de dióxido de carbono em cadelas pré-púberes e adultas submetidasà ovário histerectomiavídeo laparoscópica ou convencional

This paper aimed to determine arterial partial pressure of carbon dioxide (PaCO2), end-expired CO2 pressure (ETCO2), and the difference between arterial and end-expired CO2 pressure (Pa - ETCO2) in prepubescent and adult bitches undergoing videolaparoscopic or conventional ovariohyterectomy (OH). Forty bitches were randomly assigned to four groups: Conventional Adult (CA), Conventional Pediatric (CP), Videolaparoscopic Adult (VA) and Videolaparoscopic Pediatric (VP). Pulse rate (PR), respiratory rate (RR), systolic, mean, and diastolic arterial pressures (SAP, MAP, DAP), ETCO2, peak inspiratory pressure (PIP), pH, arterial partial pressure of oxygen (PaO2), PaCO2, base excess (BE) and HCO3 - were measured. Based on the PaCO2 and ETCO2 values, Pa-ETCO2 was determined. There was no significant difference in PaCO2 between the VA (42.5±5.2 to 53.7±5.2) and VP (48.4±5.4 to55.4±5.7) groups. During the postoperative period, all groups presented with hypertension. However, mild hypertension (SAP 150 to 159mmHg) was observed in the VP group as compared to severe hypertension (SAP>180mmHg) in the CA group, suggesting that both the age range and videolaparoscopic OH are associated with lower levels of hypertension during the postoperative period in dogs.(AU)

O objetivo deste estudo foi determinar a pressão parcial de dióxido de carbono (PaCO2), pressão ao final da expiração de CO2 (ETCO2) e diferença artério-alveolar de CO2 (Pa-ETCO2) em cadelas pré-púberes e adultas submetidas à ovário-histerectomia (OH) videolaparoscópica ou convencional. Foram distribuídas 40 cadelas em quatro grupos: Convencional Adulto (CA), Convencional Pediátrico (CP), Videolaparoscópico Adulto (VA) e Videolaparoscópico Pediátrico (VP). Foram mensurados frequência de pulso (FP), frequência respiratória (FR), pressões arteriais sistólica (PAS), média (PAM) e diastólica (PAD), ETCO2, pressão de pico inspiratória (PIP), pH, pressão parcial arterial de oxigênio (PaO2), PaCO2, excesso de bases (EB) e HCO3 -. Com base nos valores de PaCO2 e ETCO2 encontrados, foi determinada a Pa-ETCO2. Não foram encontradas diferenças significativas nos valores de PaCO2 entre os grupos VA (42.5±5.2-53,7±5,2) e VP (48.4±5.4 - 55,4±5,7). Todos os grupos apresentaram hipertensão arterial no período pós-operatório. Entretanto, o grupo VP apresentou hipertensão moderada (PAS 150-159mmHg) em comparação ao grupo CA, que apresentou hipertensão severa (PAS>180 mmHg), sugerindo que tanto a faixa etária, quanto a execução de OH por videolaparoscopia, estão associadas a menores taxas de hipertensão pós-operatória em cadelas.(AU)

Redox, acid-base and clinical analysis of preterm and term neonatal lambs

During pregnancy, fetal lambs are exposed to low oxygen tension. Thus, an effective antioxidant mechanism is partially developed which sensitizes fetus to oxidative stress. Consequently, term and preterm neonates are susceptible to molecular and cellular injury caused by oxygen species (ROS). This study aimed to evaluate the development of antioxidant enzymes and oxidative profile of preterm (135 days of pregnancy) and term (145 days of pregnancy) neonatal lambs, correlating with clinical analysis. Preterm lambs had significantly (P ≤ 0.05) lower score of vitality (4.00 ± 1.10), bradycardia (99 ± 34 bpm) and bradypnea (13 ± 10 mpm). However, both groups were normothermic and euglycemic. Preterm group had low blood pH (7.07 ± 0.10) and both groups had hypercapnia, more severe in preterm group (85.52 ± 18.65 mmHg). In addition, premature newborns had lower pO2 (10.67 ± 5.65 mmHg) and SO2 (6.17 ± 5.85%) values. No significant difference (P ≥ 0.05) on antioxidant enzymes and oxidative stress were verified among experimental groups, although glutathione peroxidase negatively correlated with Apgar score, heart rate, SO2 and pO2 . Our data show that preterm neonates are less adapted to the odds of labor and to overcome the immediate changes of extra-uterine life. Furthermore, we verified an influence of glutathione peroxidase in controlling oxidative stress, which highlights mature enzymatic mechanisms of cell redox, even in premature lambs.(AU)

Redox, acid-base and clinical analysis of preterm and term neonatal lambs

During pregnancy, fetal lambs are exposed to low oxygen tension. Thus, an effective antioxidant mechanism is partially developed which sensitizes fetus to oxidative stress. Consequently, term and preterm neonates are susceptible to molecular and cellular injury caused by oxygen species (ROS). This study aimed to evaluate the development of antioxidant enzymes and oxidative profile of preterm (135 days of pregnancy) and term (145 days of pregnancy) neonatal lambs, correlating with clinical analysis. Preterm lambs had significantly (P ≤ 0.05) lower score of vitality (4.00 ± 1.10), bradycardia (99 ± 34 bpm) and bradypnea (13 ± 10 mpm). However, both groups were normothermic and euglycemic. Preterm group had low blood pH (7.07 ± 0.10) and both groups had hypercapnia, more severe in preterm group (85.52 ± 18.65 mmHg). In addition, premature newborns had lower pO2 (10.67 ± 5.65 mmHg) and SO2 (6.17 ± 5.85%) values. No significant difference (P ≥ 0.05) on antioxidant enzymes and oxidative stress were verified among experimental groups, although glutathione peroxidase negatively correlated with Apgar score, heart rate, SO2 and pO2 . Our data show that preterm neonates are less adapted to the odds of labor and to overcome the immediate changes of extra-uterine life. Furthermore, we verified an influence of glutathione peroxidase in controlling oxidative stress, which highlights mature enzymatic mechanisms of cell redox, even in premature lambs.

EFEITOS DO PROPOFOL ASSOCIADO OU NÃO À XILAZINA OU DEXMEDETOMIDINA NA INDUÇÃO DA ANESTESIA, EM SUÍNOS PRÉ-MEDICADOS COM CETAMINA E MIDAZOLAM E MANTIDOS COM ISOFLUORANO

Objetivou-se comparar os efeitos do propofol isolado ou associado a dexmedetomidina ou xilazina, na indução da anestesia em suínos pré-medicados com cetamina e midazolam e mantidos com isofluorano. Foram utilizados oito animais (n=24), pré-medicados com cetamina na dose de 10 mg/kg e midazolam na dose de 0,5 mg/kg. Os suínos compuseram três grupos, denominados GP (propofol isolado), GPD (propofol e dexmedetomidina), GPX (propofol e xilazina). Foi utilizada dexmedetomidina na dose de 2 g/kg para o GPD e de xilazina na dose de 0,5 mg/kg para o grupo GPX, seguido de bolus de propofol sendo a dose calculada pelo total de volume infundido. Foram mensurados parâmetros cardiorrespiratórios em todos os grupos, 15 minutos após a administração intramuscular da associação de cetamina e midazolam (M15), imediatamente após a intubação (Mint1) e sucessivamente foram avaliados a cada dez minutos, durante uma hora, correspondendo aos momentos Mint10, Mint20, Mint30, Mint40, Mint50 e Mint60. Complementarmente, foram avaliadas algumas variáveis do período de recuperação e escores de qualidade de indução e intubação. A dose do propofol necessária para a intubação orotraqueal foi mensurada em todos os grupos. Os dados relacionados aos animais no pré e pós-anestésico, foram avaliados através do teste não paramétrico de Kruskal-Wallis para variáveis quantitativas e teste exato de Fisher para tabelas de contingência. Para avaliação dos momentos e grupo anestésicos foi utilizado a ANOVA. Os valores foram significativos quando o cálculo da diferença mínima apresentou p < 0,05. O tempo de extubação foi menor no grupo GPD, assim como o tempo para capacidade de se locomover do grupo GP foi menor que o GPX. O grupo GP apresentou maior numero ocorrências como apneia. Na variável frequência respiratória no momento M15 o grupo GPD apresentou maiores médias que os demais momentos e o grupo GP exibiu médias maiores no momento M15 quando comparado ao Mint1, Mint10, Mint30 e Mint40. Para a variável dióxido de carbono ao final da expiração (ETCO2), o grupo GP apresentou valores menores que o GPX e GPD. A saturação da Oxihemoglobina (SpO2) exibiu médias menores apenas no momento M15 nos grupos GP e GPX. Na avaliação cardiovascular o grupo GP apresentou médias menores de frequência cardíaca que os demais em todos os momentos. As demais variáveis não apresentaram diferença estatísticas significativa entre si. Conclui-se que, a associação de propofol associado a xilazina ou dexmedetomidina promove alterações cardiorrespiratorias discretas. A xilazina ou dexmedetomidina, quando associadas ao propofol, promovem redução na sua dose em 26% e 13%, respectivamente. A dexmedetomidina apresentou redução de 37% do consumo de isofluorano e em suínos os fármacos em teste determinam hipercapnia.

The objective is to compare the effects of propofol alone or associated with dexmedetomidine or xylazine, in inducing anesthesia in pigs premedicated with ketamine and midazolam and using isofluorane. Twenty-four animals (n = 8) were used, premedicated with ketamine at a dose of 10 mg / kg and midazolam at a dose of 0.5 mg / kg. The pigs were composed in three groups, called GP (propofol alone), GPD (propofol and dexmedetomidine), GPX (propofol and xylazine). A dose of propofol was provided by the total volume infused and its administration after the dexmedetomidine bolus at a dose of 2 g / kg for the GPD and xylazine at a dose of 0.5 mg / kg for the GPX group. Cardiorespiratory parameters were measured in all groups, 15 minutes after the intramuscular administration of the combination of ketamine and midazolam (M15), immediately after intubation (Mint1) and successively they were taken every ten minutes, for one hour, corresponding to the Mint10 moments, Mint20, Mint30, Mint40, Mint50 and Mint60. In addition, the recovery period and induction and intubation quality scores were taken. A dose of propofol required for orotracheal intubation was measured in all groups. The data related to animals in the pre and post-anesthetic, were obtained through the Kruskal-Wallis non-parametric test for quantitative variables and Fisher's exact test for contingency tables. To assess the moments and anesthetic group, an ANOVA was used. The values were calculated when the difference calculation showed p <0.05. The extubation time was different between the GP, GPD and GPX groups, as well as the time to assume the quadrupedal position of the GP group was different from the GPX. The GP group has a greater number of reactions such as apnea. In the variable respiratory rate, the GPD group showing a significant difference at the M15 moment and the GP group showed higher averages at the M15 moment when compared to Mint1, Mint10, Mint30 and Mint40. For the variable carbon dioxide at the end of expiration (ETCO2), the GP group had lower values than the GPX and GPD. Oxyhemoglobin (SpO2) saturation showed results only at the moment M15 in the GP and GPX groups. In the cardiovascular evaluation, the GP group presented lower heart rate values than the others at all times. The other variables do not differentiate between each other. It can be concluded that the association of xylazine and dexmedetomidine and propofol promotes mild cardiorespiratory changes. Xylazine and dexmedetomidine, when combined with propofol, reduce its dose by 26% and 13%, respectively. The dexmedetomidine showed a 37% reduction in isoflurane and in swine the drugs tested determine hypercapnia.

Avaliação endoscópica das vias aéreas, do perfil de gases, dos eletrólitos e do equilíbrio ácido-base em equinos submetidos ao treinamento de três tambores / Endoscopic airway, blood gas, electrolytes, and acid-base in equine submitted to three-barrel training

O objetivo deste estudo foi avaliar as vias aéreas por endoscopia, o perfil de gases, de eletrólitos e o equilíbrio ácido-base de equinos da raça Quarto de Milha (QM) antes e após o exercício de três tambores. Dezesseis cavalos, divididos em dois grupos de oito animais, treino regular (TR - cinco vezes) e treino esporádico (TE - duas vezes por semana), foram utilizados no experimento. A endoscopia foi realizada antes e 90 min após o exercício. Foram realizadas duas coletas de sangue por punção da artéria facial transversa antes do aquecimento (M0) e imediatamente após o exercício (M1), e as leituras foram realizadas com o I-Stat(r). Foram determinadas PCO2, PO2, SO2, pH, BE, HCO3 e TCO2, Na+, K+, iCa, glicose, Hg e Ht. Foi utilizada ANOVA com medidas repetidas no tempo para comparações dos grupos e dos momentos (P<0,05). A HFL acometeu em grau leve (1-2) os animais de ambos os grupos, com 8/8 (100%) no TR e 5/8 (62,5%) no TE. Observou-se presença de secreção serosa na traqueia em 4/8 (50%) para ambos os grupos. A HPIE acometeu em grau leve (1-2) os animais de ambos os grupos, com 4/8 (50%) no grupo TR e 3/8 (37,5%) no grupo TE. Os animais com grau 2 de HPIE apresentaram leve hipoxemia e hipercapnia pós-exercício. SO2, PCO2, pH, HCO3, BE, K e iCa+ não diferiram estatisticamente (P>0,05) entre os grupos. Os cavalos da raça QM submetidos ao exercício de TT apresentam HPIE e acidose metabólica.(AU)

The aim of this study was to evaluate the airways by endoscopy, gas profile, electrolytes and acid-base balance of horses in the Quarter Horse (QM) race before and after training three drums. Sixteen horses divided into two groups of 8 animals, with regular training (RT - 5 times a week) and sporadic training (ET - 2 times a week) were used in the experiment. Endoscopy was performed before and 90 min after training. Two blood samples were taken by puncturing the transverse facial artery before heating (M0) and immediately after training (M1), and the readings were performed with the I-Stat(r). PCO2, PO2, SO2, pH, BE, HCO3 and TCO2, Na +, K +, iCa, Glucose, Hg, and Ht were determined. ANOVA was used with repeated measures over time for comparisons of groups and time (P<0.05). The HFL befell was mild (1-2), the animals from both groups with 8/8 (100%) in the TR and 5/8 (62.5%) for the TE. There was presence of serous trachea 4/8 (50%) for both groups. The EIPH befell was mild (1-2) in the animals from both groups with 4/8 (50%) in the RT group and 3/8 (37.5%) for the TE group. Animals with grade 2 EIPH had mild hypoxemia and hypercapnia after exercise. The SO2, PCO2, pH, HCO3, BE, K, and iCa did not differ P <0.05 between groups. QM race submitted to TT exercise have EIPH and metabolic acidosis.(AU)

Avaliação endoscópica das vias aéreas, do perfil de gases, dos eletrólitos e do equilíbrio ácido-base em equinos submetidos ao treinamento de três tambores / Endoscopic airway, blood gas, electrolytes, and acid-base in equine submitted to three-barrel training

O objetivo deste estudo foi avaliar as vias aéreas por endoscopia, o perfil de gases, de eletrólitos e o equilíbrio ácido-base de equinos da raça Quarto de Milha (QM) antes e após o exercício de três tambores. Dezesseis cavalos, divididos em dois grupos de oito animais, treino regular (TR - cinco vezes) e treino esporádico (TE - duas vezes por semana), foram utilizados no experimento. A endoscopia foi realizada antes e 90 min após o exercício. Foram realizadas duas coletas de sangue por punção da artéria facial transversa antes do aquecimento (M0) e imediatamente após o exercício (M1), e as leituras foram realizadas com o I-Stat(r). Foram determinadas PCO2, PO2, SO2, pH, BE, HCO3 e TCO2, Na+, K+, iCa, glicose, Hg e Ht. Foi utilizada ANOVA com medidas repetidas no tempo para comparações dos grupos e dos momentos (P<0,05). A HFL acometeu em grau leve (1-2) os animais de ambos os grupos, com 8/8 (100%) no TR e 5/8 (62,5%) no TE. Observou-se presença de secreção serosa na traqueia em 4/8 (50%) para ambos os grupos. A HPIE acometeu em grau leve (1-2) os animais de ambos os grupos, com 4/8 (50%) no grupo TR e 3/8 (37,5%) no grupo TE. Os animais com grau 2 de HPIE apresentaram leve hipoxemia e hipercapnia pós-exercício. SO2, PCO2, pH, HCO3, BE, K e iCa+ não diferiram estatisticamente (P>0,05) entre os grupos. Os cavalos da raça QM submetidos ao exercício de TT apresentam HPIE e acidose metabólica.(AU)

The aim of this study was to evaluate the airways by endoscopy, gas profile, electrolytes and acid-base balance of horses in the Quarter Horse (QM) race before and after training three drums. Sixteen horses divided into two groups of 8 animals, with regular training (RT - 5 times a week) and sporadic training (ET - 2 times a week) were used in the experiment. Endoscopy was performed before and 90 min after training. Two blood samples were taken by puncturing the transverse facial artery before heating (M0) and immediately after training (M1), and the readings were performed with the I-Stat(r). PCO2, PO2, SO2, pH, BE, HCO3 and TCO2, Na +, K +, iCa, Glucose, Hg, and Ht were determined. ANOVA was used with repeated measures over time for comparisons of groups and time (P<0.05). The HFL befell was mild (1-2), the animals from both groups with 8/8 (100%) in the TR and 5/8 (62.5%) for the TE. There was presence of serous trachea 4/8 (50%) for both groups. The EIPH befell was mild (1-2) in the animals from both groups with 4/8 (50%) in the RT group and 3/8 (37.5%) for the TE group. Animals with grade 2 EIPH had mild hypoxemia and hypercapnia after exercise. The SO2, PCO2, pH, HCO3, BE, K, and iCa did not differ P <0.05 between groups. QM race submitted to TT exercise have EIPH and metabolic acidosis.(AU)

EFEITO DA TEMPERATURA DE INCUBAÇÃO NO METABOLISMO, TERMORREGULAÇÃO E QUIMIOSSENSIBILIDADE DE FRANGOS

O primeiro terço da incubação é determinante para o desenvolvimento embrionário, sendo que a temperatura é considerada um dos fatores mais importantes, pois pequenas flutuações deste parâmetro podem afetar a qualidade e a taxa de sobrevivência dos embriões. Desta forma, objetivo do presente estudo foi avaliar os efeitos da manipulação térmica durante a incubação sobre o consumo de oxigênio, temperatura corporal, respostas ventilatórias à hipóxia e hipercapnia em pintainhos machos e fêmeas de 3 e 14 dias de idade (d). Foram incubados ovos férteis de matrizes da linhagem Cobb®, classificados de acordo com o peso, provenientes de matrizes com idade entre 48 a 52 semanas, procedentes de incubatório comercial, de acordo com os seguintes tratamentos: Controle (Control) - ovos incubados a 37,5oC (durante todo o período incubatório); Frio (Cold) - ovos incubados a 36oC (6 horas/ dia, por 5 dias); Quente (Hot) - ovos incubados a 39oC (6 horas/ dia, por 5 dias). Após os 5 primeiros dias de incubação, os ovos dos tratamentos Frio e Quente permaneceram em temperatura de 37,5oC até a eclosão. Após a eclosão os animais foram sexados e os seguintes parâmetros foram avaliados: massa do pulmão e coração; temperatura corporal; consumo de O2 e ventilação em condições basais, e após a exposição à hipóxia (10%O2) ou à hipercapnia (7%CO2). Os dados foram avaliados quanto ao atendimento das pressuposições de homogeneidade das variâncias e normalidade dos erros estudentizados e submetidos à análise de variância de duas vias e em caso de diferença significativa, as médias foram comparadas pelo teste de Tukey a 5% de probabilidade. A massa corpórea dos animais incubados a 36oC, em ambas idades, foi maior comparada aos grupos quente (machos e fêmeas) e controle (exceto os machos 3d). A temperatura de incubação não influenciou no peso do coração dos animais 3d (p>0,05). No entanto, animais 14d incubados a 39oC apresentaram o peso do coração superior aos animais do grupo controle. Não houve diferença significativa no peso dos pulmões, em ambas as idades e sexo. Não houve diferença significativa entre os tratamentos na VE, VO2 e VE / VO2 dos animais 3d, durante a exposição ao ar ambiente. No entanto, fêmeas 14d incubadas a 39oC apresentaram uma diminuição de VE. Ambos machos e fêmeas 14d incubados a 39oC apresentaram menor VO2 e um aumento na Tb comparados ao grupo controle. Além disso, fêmeas 14d incubadas a 36oC apresentaram menor Tb comparadas aos animais incubados a 37,5 e 39oC. Sob exposição ao CO2, a resposta hiperventilatória (VE / VO2) foi atenuada nas fêmeas 3d e machos 14d incubados a 36oC e nos machos e fêmeas 14d incubadas a 39oC, principalmente afetando VE. Frente à hipóxia, fêmeas 3d incubadas a 36oC apresentaram uma hiperventilação atenuada modulada por uma menor resposta hipometabólica, comparadas ao grupo controle. No entanto, em fêmeas 14d incubadas a 36oC, o aumento de VE sob hipóxia foi maior e a resposta hipometabólica foi atenuada em comparação com o grupo controle, o que resultou em nenhuma alteração no equivalente ventilatório. Não houve efeito do tratamento na Tb dos animais machos e fêmeas 3d, frente hipercapnia e hipóxia. No entanto, fêmeas 14d incubadas a 36oC apresentaram uma queda atenuada na Tb comparada ao grupo controle (7% CO2) e grupos controle e quente (10% O2). Com relação a Tb dos machos 14d, o único efeito do tratamento foi observado frente hipóxia, onde machos 14d apresentaram uma queda acentuada comparada ao grupo controle. Em conclusão, a manipulação térmica afeta mais a hiperventilação induzida pela hipercapnia comparado ao desafio hipóxico. Em ambas idades, as fêmeas são mais afetadas pela manipulação térmica do que os machos.

The first third of the incubation is crucial for embryonic development, and temperature is considered one of the most important factors, as small fluctuations in this parameter can affect the quality and survival rate of embryos. Thus, the aim of the present study was to evaluate the effects of thermal manipulation during incubation on oxygen consumption, body temperature, ventilatory responses to hypoxia and hypercapnia in male and female chicks aged 3 and 14 days old (d). Fertile eggs from breeders of the Cobb® line, incubated according to weight, from breeders aged 48 to 52 weeks, from a commercial hatchery, were incubated, according to the following treatments: Control - eggs incubated at 37.5 ºC (during the entire incubation period); Cold - eggs incubated at 36ºC (6 hours/ day, for 5 days); Hot - eggs incubated at 39ºC (6 hours/ day, for 5 days). After the first 5 days of incubation, the eggs of the Cold and Hot treatments remained at a temperature of 37.5ºC until hatching. After hatching, the animals were sexed and the following parameters were evaluated: lung and heart weight; body temperature; consumption of O2 and ventilation in baseline conditions, and after exposure to hypoxia (10% O2) or hypercapnia (7% CO2). The data were evaluated for compliance with the assumptions of homogeneity of variances and normality of the student errors and submitted to the Two-way ANOVA analysis and in case of significant difference, the means were compared using the Tukey test at 5% probability. The body mass of the animals incubated at 36ºC, in both ages, was higher compared to the hot groups (males and females) and control groups (except the 3d males). The incubation temperature did not influence the heart weight of the 3d animals (p>0.05). However, 14d animals incubated at 39ºC had a higher heart weight than animals in the control group. There was no significant difference in lung weight at both ages and sex. There was no significant difference between treatments in the V E, V O2 and V E/ V O2 of the 3d animals, during exposure to ambient air. However, 14d females incubated at 39ºC showed a decrease in V E. Both 14d males and females incubated at 39ºC showed lower V O2 and an increase in Tb compared to the control group. In addition, the 14d females incubated at 36ºC showed lower Tb compared to animals incubated at 37.5 and 39ºC. Under exposure to CO2, the hyperventilatory response (V E/ V O2) was attenuated in the 3d females and 14d males incubated at 36ºC and in the 14d males and females incubated at 39ºC, mainly affecting V E. Facing hypoxia, the 3d females showed an attenuated hyperventilation modulated by a lower hypometabolic response, compared to the control group. However, in 14d females incubated at 36ºC, the increase in V E under hypoxia was greater and the hypometabolic response was attenuated compared to the control group, which resulted in no change in the ventilatory equivalent. No effect of the treatment was observed in 3d male and female animals Tb, during hypercapnia and hypoxia. However, 14d females incubated at 36ºC showed an attenuated drop in Tb compared to the control group (7% CO2 and 10% O2) and hot group (10% O2). Regarding 14d males, the only significant difference was observed during hypoxia, where males incubated at 39ºC showed a sharp drop in Tb compared to the control group. In conclusion, thermal manipulation affects hypercapnia-induced hyperventilation more than hypoxic challenge. At both ages, females are more affected by thermal manipulation than males.

Avaliação da oxigenação de cães hígidos sob ventilação não invasiva com diferentes frações inspiradas de oxigênio

A ventilação mecânica invasiva é uma modalidade respiratória indicada para pacientes com doenças pulmonares graves ou em hipóxia por causas diversas. Devido aos seus riscos inerentes como volutrauma, barotrauma, biotrauma, contaminação de vias aéreas e altos custos operacionais, métodos alternativos que consigam manter a adequada oxigenação têm sido aplicados na medicina veterinária. Dentre os diferentes métodos de ventilação não invasiva por pressão positiva, destaca-se a pressão positiva contínua nas vias aéreas (CPAP), que pode ser realizada por meio de máscara facial em cães com ou sem lesões pulmonares. Alguns estudos têm demostrado que o CPAP é capaz de elevar a pressão parcial arterial de oxigênio (PaO2), mas pouco se conhece sobre a aplicação do método com menores frações de oxigênio inspirado. O objetivo deste trabalho foi avaliar a aplicação do modo de ventilação por pressão positiva contínua nas vias aéreas em cães hígidos sedados, via máscara facial e comparar a oxigenação arterial quando oferecido diferentes frações de oxigênio inspiradas (FiO2). Desta forma, objetivou-se no presente trabalho avaliar a exequibilidade e benefícios da ventilação por pressão positiva contínua nas vias aéreas (CPAP) em cães hígidos sedados via máscara facial. Foram utilizados oito cães dolicocefálicos e mesocefálicos, sem raça específica, de ambos os sexos e de idade entre 1,5 e 6 anos. Os cães foram colocados em um só grupo para tratamento com FiO2 de 21, 50 e 100%, separados em sete momentos (M0 a M6), alternados com ar ambiental e sedados com acepromazina e morfina. As concentrações de PaO2 se elevaram após os tratamentos com FiO2 de 50 e 100% com uso de CPAP, mas não sob FiO2 de 21%. O uso da máscara facial levou a um aumento progressivo nas concentrações da pressão parcial arterial de dióxido de carbono e diminuição do pH arterial, embora não tenha ocorrido hipercapnia e acidemia. O método de ventilação por CPAP com uso de máscara facial se mostrou desconfortável para os animais e pouco eficiente na elevação dos níveis de PaO2.

Invasive mechanical ventilation is a respiratory modality indicated for patients with severe pulmonar diseases ou hypoxia caused by several factors. Due to its inherent risks such as volutrauma, barotrauma, biotrauma, airway contamination and high operational costs, alternative methods that can maintain adequate oxygenation have been applied in veterinary medicine. Amongst the different non invasive positive pressure ventilation methods, the continuous positive airway pressure (CPAP) stands out, wich can be achieved by face mask in dogs with or without pulmonary lesions. Some studies have been demonstrating that CPAP is capable of elevating oxygen arterial parcial pressure (PaO2), but not much is known about the methods application with smaller inspired fractions of oxygen (FiO2). The goal of the present study was to evaluate the application of the continuous positive pressure ventilation on airways of sedated dogs, by way of facial mask and compare arterial oxygenation when offered with different inspired fractions of oxygen. Thus, it was aimed to stabilish smaller inspired fractions of oxygen that can maintain adequate PaO2 levels for the canine species. Eight dolichocephalic and mesocephalic dogs, with no spefic breed, from both sexes and aged between 1,5 and 6 years were utilized. All dogs were put in a single group for treatment with FiO2 of 21, 50 and 100%, separated in seven moments (M0 to M6), alternated with room air and sedated with acepromazine and morphine. PaO2 concentrations were elevated after treatments with FiO2 of 50 and 100% with CPAP use, but not under FiO2 of 21%. The use of a face mask led to a progressive increase of carbon dioxide arterial parcial pressure and decay of arterial pH, altough without hypercapnia or acidemia. The CPAP ventilation method with the use of a face mask seemed to be umconfortable for animals and with little efficacy in elevating PaO2 levels.

Performance of broilers submitted to high CO2 levels during incubation combined with temperature fluctuations at late post-hatch

Incubation represents around 1/3 of the life cycle of broilers of modern strains; therefore, the appropriate management of this period is crucial to ensure the quality of the neonate. An experiment evaluated the effect of carbon dioxide concentrations during incubation on the live performance, heart morphology, and differential leukocyte count in the blood of broilers submitted to fluctuating temperatures between 35 and 42 days of age. In total, 2,520 fertile eggs were distributed according to a completely randomized design with four CO2 concentrations (4,000; 6,000; 8,000 and 10,000 ppm) during the first ten days of incubation, after which all eggs were incubated at the same CO2 level (4,000 ppm). After hatching, male chicks were placed in the experimental broiler houses, and at 35 days of age, 25 birds from each level of CO2 were separated and placed in cages to study the effect of cyclic temperature variations up to 42 days of age on their live performance, heterophil:lymphocyte ratio, and heart morphology. At 42 days of age, blood was collected for hematology and two birds per replicate were sacrificed and evaluated for ascites score and heart and liver relative weights. Heart morphology was assessed by analyzing digital images. In this experiment, hypercapnia during incubation and fluctuating temperatures during the growout did not affect mortality, ascites score, heart and liver relative weights, or heart characteristics (p>0.05). However, heterophill:lymphocyte ratio increased (p 0.05) with increasing carbon dioxide concentrations during incubation. It was concluded that high CO2 levels during incubation did not influence the resistance of broilers to fluctuating temperatures during the last week of age.

Performance of broilers submitted to high CO2 levels during incubation combined with temperature fluctuations at late post-hatch

Incubation represents around 1/3 of the life cycle of broilers of modern strains; therefore, the appropriate management of this period is crucial to ensure the quality of the neonate. An experiment evaluated the effect of carbon dioxide concentrations during incubation on the live performance, heart morphology, and differential leukocyte count in the blood of broilers submitted to fluctuating temperatures between 35 and 42 days of age. In total, 2,520 fertile eggs were distributed according to a completely randomized design with four CO2 concentrations (4,000; 6,000; 8,000 and 10,000 ppm) during the first ten days of incubation, after which all eggs were incubated at the same CO2 level (4,000 ppm). After hatching, male chicks were placed in the experimental broiler houses, and at 35 days of age, 25 birds from each level of CO2 were separated and placed in cages to study the effect of cyclic temperature variations up to 42 days of age on their live performance, heterophil:lymphocyte ratio, and heart morphology. At 42 days of age, blood was collected for hematology and two birds per replicate were sacrificed and evaluated for ascites score and heart and liver relative weights. Heart morphology was assessed by analyzing digital images. In this experiment, hypercapnia during incubation and fluctuating temperatures during the growout did not affect mortality, ascites score, heart and liver relative weights, or heart characteristics (p>0.05). However, heterophill:lymphocyte ratio increased (p 0.05) with increasing carbon dioxide concentrations during incubation. It was concluded that high CO2 levels during incubation did not influence the resistance of broilers to fluctuating temperatures during the last week of age.

Relevância da calibração na acuidade do oxicapnógrafo mainstream DL500 DeltaLife em cães submetidos à anestesia inalatória

XAVIER, N.V. Relevância da calibração na acuidade do oxicapnógrafo mainstream DL500 DeltaLife em cães submetidos à anestesia inalatória. 2019, 76 p. Dissertação (mestrado) Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de São Paulo, Pirassununga, 2019. A monitoração da função pulmonar permite identificar precocemente alterações de trocas gasosas e metabólicas sendo a capnometria o método não invasivo de eleição, considerando que existe uma correlação entre a PaCO2 e a ETCO2. O presente estudo objetivou avaliar a correlação e concordância dos valores de ETCO2 aferidos pelo monitor oxicapnógrafo mainstream DL500 desenvolvido pela DeltaLife. Para isso, o total de 33 cães foram submetidos à anestesia inalatória com isofluorano e mantidos em ventilação mecânica controlada por volume (10 a 15ml/kg) ou pressão (7 a 15cmH20). O estudo foi dividido em três fases, sendo que ao término da primeira e da segunda foram realizadas calibrações no monitor em teste pela empresa fabricante. Todos os animais foram submetidos a três tratamentos distintos (frações de CO2 expiradas) a saber: normocapnia, hipercapnia e hipocapnia (alvo de 40, 60 e 20mmHg, respectivamente). A definição da ordem fora randomizada e disposta sob quadrado latino, e os valores de ETCO2 alcançados com o ajuste da , com valor de mínimo de 3 e máximo de 35 mpm, para hipercapnia e hipocapnia respectivamente. Ao final de cada tratamento fora colhida uma amostra de sangue arterial para avaliar a concordância dos dados obtidos pelo monitor mainstream com os valores de PaCO2 bem como comparar com o monitor Vamos, tido como referência e já usado na rotina anestésica de pequenos animais. Foi possível constatar que houve melhora significativa na acurácia das informações obtidas pelo DL500 após a segunda calibração. Isso porque, na terceira fase, em normocapnia os valores de média obtidos de PaCO2 foram 44,65 mmHg e ambos os monitores apresentaram ETCO2 médio de 37 mmHg. Em hipocapnia essa tendência também foi observada quando a PaCO2 mostrou valores médios de 27,91 mmHg, o Vamos de 22mmHg e o DL500 23mmHg. Somente em hipercapnia o gradiente entre esses parâmetros aumentou, quando comparamos a PaCO2 obtida de 70,37mmHg, com os valores aferidos pelos monitores, sendo o Vamos 60 mmHg e DL500 58 mmHg. Pôde-se então, assegurar a legitimidade dos dados de ETCO2 fornecidos pelo DL500, estimulando a indústria nacional no desenvolvimento de tecnologias voltadas para o mercado veterinário.

XAVIER, N.V. Relevance of acuity calibration of DeltaLife DL500 mainstream oxycapnograph in dogs under inhalational anesthesia. 2019. 76 p. Dissertation (mestrado) Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de São Paulo, Pirassununga, 2019 The pulmonary function monitoration allows early identification of changes in the gaseous and metabolic exchange, and capnometry is the noninvasive method of choice, considering that there is a correlation and agreement of ETCO2 values measured by the DL500 mainstream oxycapnograph monitor developed by DeltaLife. For this, 33 dogs were submitted to inhalation anesthesia with isoflurane and maintained in mechanical ventilation cotrolled by volum (10 to 15 mL/Kg) or pressure (7 to 15 cmH20). The study was divided into three phases, and at the end of the first and the second phase calibrations were carried out by the manufacturing company. All animals were submitted to three differents treatments (Expired CO2 fractions): normocapnia, hypercapnia and hypocapnia (40, 60 and 20 mmHg, respectively). The order definition was randomized and arranged in Latin Square, and the ETCO2 values reached with the adjustment, with minimum value of 3 mpm and maximum of 25 mpm, for hypercapnia and hypocapnia respectively. At the end of each treatment a sample of arterial blood was collected to evaluate the agreement of the data obtained by the mainstream monitor with the values of PaCO2 as well as to compare with the Vamos monitor, considered as a reference and already used in the anesthetic routine of small animals. It was possible to verify that there was a significant improvement in the accuracy of the information obtained by the DL500 monitor after the second calibration. This is because, in the third phase, in normocapnia the mean values obtained for PaCO2 were 44.65 mmHg and both monitors had an ETCO2 value of 37 mmHg. In hypocapnia this trend was also observed when the PaCO2 showed medium values of 27.91 mmHg, the Vamos of 22 mmHg and the DL500 23 mmHg. Only in hypercapnia the gradient between these parameters increased, when we compared the PaCO2 obtained of 70.37 mmHg, with the values measured by the monitors, being the Vamos 60 mmHg and DL500 58 mmHg. It was possible to ensure the legitimacy of the ETCO2 data provided by the equipment under study, stimulating the national industry in the development of technologies aimed to the veterinary market.

Performance of broilers submitted to high CO2 levels during incubation combined with temperature fluctuations at late post-hatch

Incubation represents around 1/3 of the life cycle of broilers of modern strains; therefore, the appropriate management of this period is crucial to ensure the quality of the neonate. An experiment evaluated the effect of carbon dioxide concentrations during incubation on the live performance, heart morphology, and differential leukocyte count in the blood of broilers submitted to fluctuating temperatures between 35 and 42 days of age. In total, 2,520 fertile eggs were distributed according to a completely randomized design with four CO2 concentrations (4,000; 6,000; 8,000 and 10,000 ppm) during the first ten days of incubation, after which all eggs were incubated at the same CO2 level (4,000 ppm). After hatching, male chicks were placed in the experimental broiler houses, and at 35 days of age, 25 birds from each level of CO2 were separated and placed in cages to study the effect of cyclic temperature variations up to 42 days of age on their live performance, heterophil:lymphocyte ratio, and heart morphology. At 42 days of age, blood was collected for hematology and two birds per replicate were sacrificed and evaluated for ascites score and heart and liver relative weights. Heart morphology was assessed by analyzing digital images. In this experiment, hypercapnia during incubation and fluctuating temperatures during the growout did not affect mortality, ascites score, heart and liver relative weights, or heart characteristics (p>0.05). However, heterophill:lymphocyte ratio increased (p 0.05) with increasing carbon dioxide concentrations during incubation. It was concluded that high CO2 levels during incubation did not influence the resistance of broilers to fluctuating temperatures during the last week of age.(AU)

SEGURANÇA E EFICÁCIA DA DEXMEDETOMIDINA EM OVINOS

A ampla utilização de ovinos como modelos experimentais em diferentes estudos e o crescente desenvolvimento de estudos relacionados a técnicas anestésicas e analgésicas nesta espécie. A dexmedetomidina, um fármaco agonista dos receptores -2 adrenérgicos é um sedativo promissor, com efeitos analgésicos, miorrelaxante e hipnótico já descrito em algumas espécies, como cães, gatos, equinos e ovinos. Sua segurança para uso em bolus em cães, gatos, ovinos e equinos já é descrita, sob a forma de administração IM e bolus IV, todavia seu uso não está livre de efeitos adversos. Dentre os principais efeitos atendimento desta espécie na clínica de ruminantes alavanca o adversos documentados estão a bradicardia com ou sem presença de arritmias, hipertensão seguida de hipotensão, depressão respiratória, edema pulmonar, hipoxemia e hipercapnia, redução do débito cardíaco, aumento da resistência vascular sistêmica, alterações da motilidade intestinal, hiperglicemia transitória, aumento da diurese, salivação e diminuição da temperatura corpórea. Uma alternativa na tentativa de minimizar os efeitos desencadeados pela administração em bolus de fármacos agonistas dos receptores -2 adrenérgicos refere-se ao uso de infusões intravenosas contínuas, que comprovadamente cardiorrespiratório e diminuem as doses de outros anestésicos, como os anestésicos inalatórios. Na medicina veterinária, estudos sobre os efeitos da dexmedetomidina em ovinos, em uso intravenoso sob infusão contínua são escassos, quando comparado a uso em cães e equinos, principalmente quando uso da dexmedetomidina isoladamente. Assim, esse trabalho teve como objetivo realizar uma revisão de literatura a fim de compilar as informações acerca do uso de agonistas -2 em ovinos, com foco na dexmedetomidina e descrever um estudo prospectivo de comparação entre bolus e e 5µg/kg/h), impactam menos na função hemodinâmica, do sistema infusão respectivamente) sobre os efeitos cardiorrespiratórios, hemodinâmicos e sedativos em ovinos. A dexmedetomidina sob administração em bolus, diminuiu significativamente intravenosa continua de dexmedetomidina (5 µg/kg o resistência vascular e periférica, não observado com o uso em infusão contínua e levou grau de sedação maior do que comparado à infusão intravenosa contínua. Desta forma, provou-se que a dexmedetomidina sob infusão intravenosa contínua, impacta menos na hemodinâmica do que o bolus, porém não promove escore de sedação suficientes para procedimentos minimamente invasivos, diferentemente do bolus, que foi eficaz.

Studies regarding anesthetic and analgesic techniques in sheep increased in the past years due to the wide usage of this species as experimental models and due to clinical care in veterinary hospitals. Dexmedetomidine, an -2 adrenergic agonist is a promising sedative drug with analgesic, myorelaxant and hypnotic effects already described in several species, such as dogs, cats and horses, but with few studies involving sheep. Its safety in dogs, cats, sheep and horses after IV bolus and IM administration has already been described, with minimal adverse effects. Bradycardia with or without arrhythmias, hypertension followed by hypotension, respiratory depression, pulmonary edema, hypoxemia and hypercapnia, reduction of cardiac output, increase in systemic vascular resistance, changes in intestinal motility, transient hyperglycemia, increased diuresis, salivation and decreased body temperature are the most common side effects documented. In order to minimize IV bolus side effects, continuous intravenous infusions can be used, which have been shown to have less impact on hemodynamic function of the cardiorespiratory system and can reduce the doses of other drugs, such as inhalational anesthetics. In veterinary medicine, studies on the effects of intravenous continuous infusion of dexmedetomidine in sheep are scarce, especially with no association with other anesthetics. Thus, the aim of this study was to compare 5g/kg intravenous bolus and 5g/kg/h continuous rate infusion of dexmedetomidine on cardiorespiratory, hemodynamic and sedative effects in sheep. Dexmedetomidine after IV bolus administration significantly decreased cardiac output, cardiac index and heart rate, increased vascular and peripheral resistance index, which were not observed after continuous rate infusion, and led to a higher degree of sedation compared to CRI. It can be concluded that dexmedetomidine CRI had less impact on hemodynamics than IV bolus administration, but it did not promote sufficient sedation score for minimally invasive procedures.