O USO DE OPIOIDES EM RUMINANTES

Ruminants, as all other animals, feel pain, which can be caused by diseases or frequently practiced procedures, such as dehorning and orchiectomy. However, in these animals the use of analgesics is still less common than ideal, requiring greater awareness, in addition to studies with drugs and protocols capable of effectively relieving pain in these species. In this context, opioids, potent analgesic drugs, are highlighted as a great option for pain control. Nevertheless, their use is still infrequent in ruminants, where studies are limited and show varied results. Therefore, the objective of this study was to review the benefits of pain control in ruminants through opioids, elucidating the analgesic possibilities with different drugs of this class and administration routes to encourage the use by veterinarians of ruminants, based on the literature already published on this subject. Even with some variable results, several studies have demonstrated the antinociceptive potential of opioids in ruminants, in addition to the sedative effects, highlighting the analgesic potential mainly through alternative routes of administration, such as transdermal fentanyl and the epidural route for various opioids, which become important options to be considered in analgesic protocols for ruminants.Os ruminantes, como todos os animais, têm capacidade de sentir dor, a qual pode ser causada por doenças ou procedimentos frequentemente praticados, como a descorna e a orquiectomia. Todavia, nesses animais, o uso de analgésicos ainda é menos comum do que o ideal, sendo necessária uma maior conscientização, além de estudos com fármacos e protocolos, capazes de aliviar a dor de maneira eficaz nessas espécies. Neste contexto, destacam-se os opioides, potentes fármacos analgésicos, sendo ótima opção para o controle da dor; entretanto, seu uso ainda é pouco frequente em ruminantes, os estudos são limitados e encontram resultados variáveis. Diante disso, o objetivo deste trabalho foi revisar os benefícios do controle da dor em ruminantes, através do uso de opioides, elucidando as possibilidades analgésicas com diferentes fármacos desta classe e vias de administração, a fim de incentivar o uso pelos médicos veterinários de ruminantes, com base na literatura já publicada sobre este assunto; uma vez que, mesmo com alguns resultados variáveis, diversos estudos têm demonstrado o potencial antinociceptivo dos opioides em ruminantes, além dos efeitos sedativos, destacando o potencial analgésico principalmente por vias de administração alternativas, como o fentanil transdérmico e a via epidural para diversos opioides, os quais tornam-se opções importantes a serem consideradas nos protocolos analgésicos para ruminantes

Anestesia intravenosa parcial (AIVP) em lobo-guará (Chrysocyon brachyurus) neonato

Background: The maned wolf (Chrysocyon brachyurus) is the largest canid in South America and the only representative of its genus. The scientific literature presents studies referring to the management and anaesthesia of the species but is scarce in case of emergency procedures, and to date, there are no reports of anaesthesia for emergency procedures in a neonatal maned wolf. Thus, this study aimed to report xenotransfusion and emergency anaesthesia for thoracic limb amputation in an approximately 8-days-old maned wolf pup.  Case: A maned wolf pup, approximately 8-days-old, with a history of an accident with an agricultural machine, was referred to the Veterinary Hospital of the Federal University of Paraná - Palotina Sector (HVP - UFPR) with a grade III open fracture of left radius and ulna. At the physical evaluation, bullous rales were observed in the right caudal lobe on pulmonary auscultation, hypoglycemia and severe dehydration, the latter being determined by the occurrence of enophthalmos, increased capillary refill time and skin turgor (3 s). The hemogram revealed regenerative hypochromic macrocytic anaemia, thrombocytopenia and leukopenia, and the chest radiograph showed alveolar pattern opacification, associated with the presence of air bronchograms in the caudal lobes, more evident on the right side, suggestive of pulmonary contusion. Considering the laboratory alterations and the need for amputation of the thoracic limb, xenotransfusion was chosen before the anaesthetic procedure. The animal was pre-medicated with methadone 0.2 mg/kg and anaesthetic induction was performed with propofol titrated to effect, requiring 10 mg/kg. This was followed by endotracheal intubation and anaesthetic maintenance using the partial intravenous technique with an infusion of 5 µg/kg/h of remifentanil and Isoflurane vaporised through a non-rebreathing system in oxygen at 0.6. Anaesthetic monitoring included heart rate and electrocardiogram tracing, respiratory rate, oxyhemoglobin saturation, end-tidal partial pressure of carbon dioxide, systemic blood pressure by the oscillometric method, and oesophageal body temperature. Although the blood tests after the transfusion showed an increase in hematocrit, changes suggestive of a delayed hemolytic reaction because of the transfusion were also noticed.  Discussion: Preanesthetic stabilisation is critical, as anaesthesia of unstable patients may result in a higher risk of anaesthetic complications. Critically ill patients may present systemic imbalances that can trigger pharmacokinetic and pharmacodynamic changes of anaesthetics and analgesics. Neonates have several marked physiological differences, since some organs are still immature, have a high body volume of water, and present a reduced amount of total fat and concentrations of circulating proteins, making it necessary to adjust protocols and doses used for these patients. Blood transfusion between the same species is always the best option, though xenotransfusion becomes an option when there is no homologous donor available. However, it can present a great risk to life, as there is a lack of studies regarding the blood typing of the species and blood compatibility tests. We concluded that there was an increase in hematocrit after 24 h of xenotransfusion and, even with signs of delayed hemolytic reaction observed in the blood test, the patient did not show specific clinical signs of transfusion reaction. The pup was sensitive to methadone but required a high dose of propofol for anaesthetic induction. The use of methadone as a pre-anaesthetic agent and the infusion of remifentanil provided adequate analgesia based on the parameters evaluated. Keywords: xenotransfusion, stabilisation, anaesthesia, neonatal. Título: Anestesia intravenosa parcial (AIVP) em uma lobo-guará(Chrysocyon brachyurus) neonata Descritores: xenotransfusão, estabilização, anestesia, neonato.Background: O lobo-guará (Chrysocyon brachyurus) é o maior canídeo da América do Sul e único representante do seu gênero. Atualmente, já existem estudos referentes ao manejo e anestesia da espécie, mas tratando-se de procedimentos de emergência, a literatura é escassa e, até o presente momento, não existem relatos de anestesia para procedimentos de emergência em lobo-guará neonato. Dessa forma, o objetivo do trabalho foi . Case: , com histórico de acidente com máquina agrícola, foi encaminhado ao Hospital Veterinário da Universidade Federal do Paraná, setor Palotina (HVP - UFPR) com fratura exposta grau III de rádio e ulna em membro torácico esquerdo. Na avaliação física observou-se presença estertor bolhoso em lobo caudal direito na ausculta pulmonar, hipoglicemia e grave desidratação, sendo a última determinada pela ocorrência de enoftalmia, No hemograma, identificou-se anemia macrocítica hipocrômica regenerativa, trombocitopenia e leucopenia, e na radiografia torácica observou-se opacificação de padrão alveolar, associado à presença de broncogramas aéreos em lobos caudais, mais evidentes do lado direito, sugestivo de contusão pulmonar. Considerando as alterações laboratoriais e a necessidade de amputação do membro torácico, optou-se pela xenotransfusão antes do procedimento anestésico. O animal foi pré-medicado com metadona 0,2 mg/kg e a indução anestésica foi realizada com propofol dose-efeito, sendo necessários 10 mg/kg. Seguiu-se intubação endotraqueal e manutenção anestésica utilizando a técnica parcial intravenosa com infusão de 5 µg/kg/h de remifentanil. O isoflurano foi vaporizado através de um sistema sem reinalação de gases em oxigênio a 0,6. Durante o procedimento foram avaliados frequência cardíaca e traçado de eletrocardiograma, frequência respiratória, saturação de oxihemoglobina, pressão parcial de dióxido de carbono ao final da expiração, pressão arterial sistêmica pelo método oscilométrico e temperatura corporal esofágica. A transfusão interespecífica terminou duas horas após o término da anestesia, sem a ocorrência de reações transfusionais imediatas. Embora os exames de sangue posteriores à transfusão evidenciaram aumento do hematócrito, notou-se também alterações sugestivas de reação hemolítica em decorrência da transfusão. Discussion: A estabilização pré-anestésica é fundamental, uma vez que a anestesia de pacientes instáveis pode resultar em maior risco de complicações anestésicas. Pacientes críticos podem apresentar desequilíbrio sistêmico que podem desencadear alterações farmacocinética e farmacodinâmica dos anestésicos e analgésicos. Neonatos apresentam diversas diferenças fisiológicas marcantes, visto que alguns órgãos ainda são imaturos, contam com um elevado volume corporal de água, uma quantidade de gordura total e concentrações de proteínas circulantes reduzidas, tornando necessário o ajuste de protocolos e doses utilizadas para esses pacientes. A transfusão de sangue entre a mesma espécie é sempre a melhor opção, no entanto, a xenotransfusão se torna uma opção quando não existe um doador homólogo disponível. Contudo, pode apresentar um grande risco à vida, pois faltam estudos referentes a tipagem sanguínea da espécie e testes de compatibilidade sanguínea. Concluiu-se que houve um aumento do hematócrito após 24 horas da xenotransfusão e mesmo com sinais de reação hemolítica tardia observadas no exame de sangue, o paciente não apresentou sinais clínicos específicos de reação transfusional. O filhote foi sensível a metadona, mas necessitou de alta dose de propofol para indução anestésica. A utilização de metadona como agente pré-anestésico e a infusão de remifentanil promoveram analgesia adequada baseado nos parâmetros avaliados. Keywords: xenotransfusion, stabilization, anesthesia, neonatal. Palavras-chave: xenotransfusão, estabilização, anestesia, neonato

Perspectivas da aplicação das conotoxinas bloqueadoras de canais para cálcio dependentes de voltagem no trauma medular

O bloqueio dos canais para cálcio dependentes de voltagem é uma estratégia importante no tratamento do trauma medular, pois previne o influxo exacerbado do cálcio que participa ativamente em processos neurodegenerativos agudos, resultando em neuroproteção com melhora das funções neurológica. Dentre esses bloqueadores, as toxinas de caramujos marinhos são peptídeos com adequada estabilidade estrutural, estudadas pelas ações específicas em canais iônicos e receptores que interferem diretamente na liberação de neurotransmissores e na neuromodulação dos neurônios motores e sensitivos da medula espinal. Elas já são utilizadas no tratamento de desordens neurológicas e mostram-se promissoras no desenvolvimento de novas terapias para o trauma medular. Portanto, objetivou-se discorrer sobre a fisiopatologia do trauma medular e a possível utilização terapêutica das toxinas de caramujo marinho, atuantes nos principais canais para cálcio dependentes de voltagem

General anesthesia in Sapajus nigritus (black capuchin)

Background: The black capuccin (Sapajus nigritus) is one of the most abundant primate specimens in Brazil. Among population control techniques, vasectomy can be used once it maintains the animal's leading behavior in the group through hormonal presence, production of spermatogenic series, and copula. However, due to their escape behavior, agitation, in addition to the impossibility of knowing the physiological state of these animals beforehand, their capture poses a considerable challenge. Thus, chemical restraint is indispensable and the use of effective and safe anesthetic protocols to animal integrity is of paramount importance. In this scenario, the present study aims to report the anesthesia of a black capuccin submitted to vasectomy.Case: A 1-year-old male, 1.1 kg monkey (Sapajus nigritus) was admitted at a Veterinary Hospital after being found on the ground in a natural reserve in the town of Assis Chateaubriand, in the west of Parana State. After clinical evaluation, the patient was submitted to vasectomy as a birth control method, before his return to the natural area, which presented overpopulation of the species. After preanesthetic examinations, the animal was considered healthy, and thus, premedicated with the combination of dexmedetomidine (10 μg/kg) and ketamine (10 mg/kg), intramuscularly. Anesthetic induction with propofol was performed to effect. Laringeal desensitization was achieved with 2% lidocaine (2 mg/kg), which allowed orotracheal intubation through direct visualization. Anesthesia was maintained with 1% isoflurane in a 0.5 oxygen fraction and spontaneous ventilation using a non-rebreathing circuit. The spermatic cord and the skin were desensitized with lidocaine (2 mg/kg). During the procedure, the animal was monitored for pulse oximetry, electrocardiogram, systolic blood pressure, body temperature, end tidal CO2 (ETCO2), and end tidal isoflurane. The animal also received 10 mL/kg/h ringer lactate throughout anesthesia and 30 mg/kg ampiciline as prophylactic antibiotic. After the completion of the surgery, inhalation anesthesia was interrupted and the animal was allowed to wake up.  Discussion: The combination of 10 µg/kg dexmedetomidine and 10 mg/kg ketamine caused intense muscle relaxation and short-term sedation, which lasted 15 min. Protocol was sufficient for veno puncture and pre-oxygenation, but doses should be increased for longer procedures. Although other authors reported physiologic alterations with higher doses of these drugs, such complications were not observed in the present case. The anesthetic induction was smooth, with no excitement or complications. Propofol was infused at 1 mg/10 s, and a total dose of 10 mg/kg was necessary for induction. This rapid infusion rate could have caused the increase in propofol total dose, as described elsewhere. Propofol and local lidocaine allowed orotracheal intubation with a 2.5 mm uncuffed neonatal tube. During surgery, analgesia was achieved with pre surgical local anesthetic and a single bolus of fentanyl during duct deferens manipulation. During anesthesia, heart rate was maintained between 140 and 170 bpm; systolic blood pressure, between 85 and 110 mmHg; respiratory rate, between 30 and 50 mpm; and ETCO2, between 25 and 30 mmHg. No assistance in ventilation was necessary. The procedure lasted one hour, and extubation occurred seven minutes after the interruption of inhalational anesthetic. Anesthesia and anesthesia recovery occurred without complications, allowing the accomplishment of a short duration surgical procedure. After the post operatory period, the animal was reintroduced to the wild, with authorization of the state environmental agency. In conclusion, low dose dexmedetomidine combined with ketamine is adequate for rapid chemical restraint of black capuccin, and do not cause physiologic alterations during isoflurane anesthesia

Braquial Plexus Block and Lumbosacral Epidural in a South American Coati (Nasua nasua)

Background: The South American coatis (Nasua nasua) are capable of adapting to different habitats, which allowed them to exchange between domestic and wild areas, increasing the occurrence of traumas. Procedures performed in this species demand anesthetic protocols that take comorbidities into account and cause minimal cardiorespiratory depression as well as rapid recovery. It is in such context that locoregional anesthesia has become an essential tool. Thus, we aim to report the use of two techniques of locoreginal block: brachial plexus block and lumbosacral epidural block, in a Nasua nasua submitted to osteosynthesis of the radius and caudectomy due to trauma.Case: A adult male coati weighing 2.3 kg was referred to the Veterinary Medical Teaching Hospital of the Universidade Federal do Paraná (UFPR) - Setor Palotina with a history of trauma. Physical examination showed crackling in the radius and ulnar region, and also abnormal angulation in the distal portion of the tail. After taking x-rays, fractures were confirmed in the distal radius and in the distal portion of the tail. The patient was referred for surgery. After 8 h of water and food withdrawal, the animal was premedicated with a combination of ketamine (10 mg/kg), midazolam (0.3 mg/kg) and methadone (0.2 mg/kg), intramuscularly (IM). Induction of anesthesia was performed with propofol titrated to effect (total dose 4 mg/kg) and anesthesia was maintained with isoflurane in spontaneous ventilation using a non-rebreathing circuit (Baraka). It was evaluated heart rate (HR), respiratory rate (RF), end-tidal CO2 (EtCO2), expired isoflurane fraction (FE´Iso), oxyhemoglobin saturation (SpO2), electrocardiography (ECG), systolic blood pressure (SBP) and core temperature (CT) using a multiparametric monitor. After the stabilization period, the animal was positioned in lateral recumbence. A subscapular brachial plexus block was performed with bupivacaine (0.2 mL/kg) using a peripheral nerve stimulator to ensure the correct perineural deposition of the local anesthetic. During anesthesia, rescue analgesia was administered when there was a 20% increase in HR, RR or SBP compared to baseline values. Thus, in this case, two rescues with fentanyl (2 µg/kg) were necessary. The animal remained stable and, at the end of the first procedure, he was placed in ventral recumbence, with the hindlimbs pulled cranially in order to locate the lumbosacral space. Epidural injection was performed with lidocaine (0.18 mL/kg). Rescue analgesia was not necessary during the caudectomy procedure. The procedure had a total duration of 3 h and extubation occurred 3 min after inhalation anesthesia withdrawal. At the end of the surgery, the animal was medicated with meloxicam (0.1 mg/kg) and methadone (0.2 mg/kg). Two h after the end of the surgery, the animal was able to feed again.Discussion: The literature is scarce regarding anesthetic techniques in the Nasua nasua species, especially in the context of locoregional anesthesia. In this report, the protocol used as pre-anesthetic medication was considered satisfactory. Brachial plexus block is a safe technique for desensitizing the forelimb for surgical procedures distal to the scapulohumeral joint. Despite some morphological differences in the spinal anatomy of coatis, there was no difficulty in identifying the epidural space or inserting the needle. The absence of complications, and the hemodynamic stability during the anesthesia period, combined with the satisfactory recovery of the patient points to the success of the techniques used in the present report

Braquial Plexus Block and Lumbosacral Epidural in a South American Coati (Nasua nasua)

Background: The South American coatis (Nasua nasua) are capable of adapting to different habitats, which allowed them to exchange between domestic and wild areas, increasing the occurrence of traumas. Procedures performed in this species demand anesthetic protocols that take comorbidities into account and cause minimal cardiorespiratory depression as well as rapid recovery. It is in such context that locoregional anesthesia has become an essential tool. Thus, we aim to report the use of two techniques of locoreginal block: brachial plexus block and lumbosacral epidural block, in a Nasua nasua submitted to osteosynthesis of the radius and caudectomy due to trauma.Case: A adult male coati weighing 2.3 kg was referred to the Veterinary Medical Teaching Hospital of the Universidade Federal do Paraná (UFPR) - Setor Palotina with a history of trauma. Physical examination showed crackling in the radius and ulnar region, and also abnormal angulation in the distal portion of the tail. After taking x-rays, fractures were confirmed in the distal radius and in the distal portion of the tail. The patient was referred for surgery. After 8 h of water and food withdrawal, the animal was premedicated with a combination of ketamine (10 mg/kg), midazolam (0.3 mg/kg) and methadone (0.2 mg/kg), intramuscularly (IM). Induction of anesthesia was performed with propofol titrated to effect (total dose 4 mg/kg) and anesthesia was maintained with isoflurane in spontaneous ventilation using a non-rebreathing circuit (Baraka). It was evaluated heart rate (HR), respiratory rate (RF), end-tidal CO2 (EtCO2), expired isoflurane fraction (FE´Iso), oxyhemoglobin saturation (SpO2), electrocardiography (ECG), systolic blood pressure (SBP) and core temperature (CT) using a multiparametric monitor. After the stabilization period, the animal was positioned in lateral recumbence. A subscapular brachial plexus block was performed with bupivacaine (0.2 mL/kg) using a peripheral nerve stimulator to ensure the correct perineural deposition of the local anesthetic. During anesthesia, rescue analgesia was administered when there was a 20% increase in HR, RR or SBP compared to baseline values. Thus, in this case, two rescues with fentanyl (2 µg/kg) were necessary. The animal remained stable and, at the end of the first procedure, he was placed in ventral recumbence, with the hindlimbs pulled cranially in order to locate the lumbosacral space. Epidural injection was performed with lidocaine (0.18 mL/kg). Rescue analgesia was not necessary during the caudectomy procedure. The procedure had a total duration of 3 h and extubation occurred 3 min after inhalation anesthesia withdrawal. At the end of the surgery, the animal was medicated with meloxicam (0.1 mg/kg) and methadone (0.2 mg/kg). Two h after the end of the surgery, the animal was able to feed again.Discussion: The literature is scarce regarding anesthetic techniques in the Nasua nasua species, especially in the context of locoregional anesthesia. In this report, the protocol used as pre-anesthetic medication was considered satisfactory. Brachial plexus block is a safe technique for desensitizing the forelimb for surgical procedures distal to the scapulohumeral joint. Despite some morphological differences in the spinal anatomy of coatis, there was no difficulty in identifying the epidural space or inserting the needle. The absence of complications, and the hemodynamic stability during the anesthesia period, combined with the satisfactory recovery of the patient points to the success of the techniques used in the present report

Anestesia intravenosa parcial (AIVP) em lobo-guará (Chrysocyon brachyurus) neonato

Background: The maned wolf (Chrysocyon brachyurus) is the largest canid in South America and the only representative of its genus. The scientific literature presents studies referring to the management and anaesthesia of the species but is scarce in case of emergency procedures, and to date, there are no reports of anaesthesia for emergency procedures in a neonatal maned wolf. Thus, this study aimed to report xenotransfusion and emergency anaesthesia for thoracic limb amputation in an approximately 8-days-old maned wolf pup.  Case: A maned wolf pup, approximately 8-days-old, with a history of an accident with an agricultural machine, was referred to the Veterinary Hospital of the Federal University of Paraná - Palotina Sector (HVP - UFPR) with a grade III open fracture of left radius and ulna. At the physical evaluation, bullous rales were observed in the right caudal lobe on pulmonary auscultation, hypoglycemia and severe dehydration, the latter being determined by the occurrence of enophthalmos, increased capillary refill time and skin turgor (3 s). The hemogram revealed regenerative hypochromic macrocytic anaemia, thrombocytopenia and leukopenia, and the chest radiograph showed alveolar pattern opacification, associated with the presence of air bronchograms in the caudal lobes, more evident on the right side, suggestive of pulmonary contusion. Considering the laboratory alterations and the need for amputation of the thoracic limb, xenotransfusion was chosen before the anaesthetic procedure. The animal was pre-medicated with methadone 0.2 mg/kg and anaesthetic induction was performed with propofol titrated to effect, requiring 10 mg/kg. This was followed by endotracheal intubation and anaesthetic maintenance using the partial intravenous technique with an infusion of 5 µg/kg/h of remifentanil and Isoflurane vaporised through a non-rebreathing system in oxygen at 0.6. Anaesthetic monitoring included heart rate and electrocardiogram tracing, respiratory rate, oxyhemoglobin saturation, end-tidal partial pressure of carbon dioxide, systemic blood pressure by the oscillometric method, and oesophageal body temperature. Although the blood tests after the transfusion showed an increase in hematocrit, changes suggestive of a delayed hemolytic reaction because of the transfusion were also noticed.  Discussion: Preanesthetic stabilisation is critical, as anaesthesia of unstable patients may result in a higher risk of anaesthetic complications. Critically ill patients may present systemic imbalances that can trigger pharmacokinetic and pharmacodynamic changes of anaesthetics and analgesics. Neonates have several marked physiological differences, since some organs are still immature, have a high body volume of water, and present a reduced amount of total fat and concentrations of circulating proteins, making it necessary to adjust protocols and doses used for these patients. Blood transfusion between the same species is always the best option, though xenotransfusion becomes an option when there is no homologous donor available. However, it can present a great risk to life, as there is a lack of studies regarding the blood typing of the species and blood compatibility tests. We concluded that there was an increase in hematocrit after 24 h of xenotransfusion and, even with signs of delayed hemolytic reaction observed in the blood test, the patient did not show specific clinical signs of transfusion reaction. The pup was sensitive to methadone but required a high dose of propofol for anaesthetic induction. The use of methadone as a pre-anaesthetic agent and the infusion of remifentanil provided adequate analgesia based on the parameters evaluated. Keywords: xenotransfusion, stabilisation, anaesthesia, neonatal. Título: Anestesia intravenosa parcial (AIVP) em uma lobo-guará(Chrysocyon brachyurus) neonata Descritores: xenotransfusão, estabilização, anestesia, neonato.Background: O lobo-guará (Chrysocyon brachyurus) é o maior canídeo da América do Sul e único representante do seu gênero. Atualmente, já existem estudos referentes ao manejo e anestesia da espécie, mas tratando-se de procedimentos de emergência, a literatura é escassa e, até o presente momento, não existem relatos de anestesia para procedimentos de emergência em lobo-guará neonato. Dessa forma, o objetivo do trabalho foi . Case: , com histórico de acidente com máquina agrícola, foi encaminhado ao Hospital Veterinário da Universidade Federal do Paraná, setor Palotina (HVP - UFPR) com fratura exposta grau III de rádio e ulna em membro torácico esquerdo. Na avaliação física observou-se presença estertor bolhoso em lobo caudal direito na ausculta pulmonar, hipoglicemia e grave desidratação, sendo a última determinada pela ocorrência de enoftalmia, No hemograma, identificou-se anemia macrocítica hipocrômica regenerativa, trombocitopenia e leucopenia, e na radiografia torácica observou-se opacificação de padrão alveolar, associado à presença de broncogramas aéreos em lobos caudais, mais evidentes do lado direito, sugestivo de contusão pulmonar. Considerando as alterações laboratoriais e a necessidade de amputação do membro torácico, optou-se pela xenotransfusão antes do procedimento anestésico. O animal foi pré-medicado com metadona 0,2 mg/kg e a indução anestésica foi realizada com propofol dose-efeito, sendo necessários 10 mg/kg. Seguiu-se intubação endotraqueal e manutenção anestésica utilizando a técnica parcial intravenosa com infusão de 5 µg/kg/h de remifentanil. O isoflurano foi vaporizado através de um sistema sem reinalação de gases em oxigênio a 0,6. Durante o procedimento foram avaliados frequência cardíaca e traçado de eletrocardiograma, frequência respiratória, saturação de oxihemoglobina, pressão parcial de dióxido de carbono ao final da expiração, pressão arterial sistêmica pelo método oscilométrico e temperatura corporal esofágica. A transfusão interespecífica terminou duas horas após o término da anestesia, sem a ocorrência de reações transfusionais imediatas. Embora os exames de sangue posteriores à transfusão evidenciaram aumento do hematócrito, notou-se também alterações sugestivas de reação hemolítica em decorrência da transfusão. Discussion: A estabilização pré-anestésica é fundamental, uma vez que a anestesia de pacientes instáveis pode resultar em maior risco de complicações anestésicas. Pacientes críticos podem apresentar desequilíbrio sistêmico que podem desencadear alterações farmacocinética e farmacodinâmica dos anestésicos e analgésicos. Neonatos apresentam diversas diferenças fisiológicas marcantes, visto que alguns órgãos ainda são imaturos, contam com um elevado volume corporal de água, uma quantidade de gordura total e concentrações de proteínas circulantes reduzidas, tornando necessário o ajuste de protocolos e doses utilizadas para esses pacientes. A transfusão de sangue entre a mesma espécie é sempre a melhor opção, no entanto, a xenotransfusão se torna uma opção quando não existe um doador homólogo disponível. Contudo, pode apresentar um grande risco à vida, pois faltam estudos referentes a tipagem sanguínea da espécie e testes de compatibilidade sanguínea. Concluiu-se que houve um aumento do hematócrito após 24 horas da xenotransfusão e mesmo com sinais de reação hemolítica tardia observadas no exame de sangue, o paciente não apresentou sinais clínicos específicos de reação transfusional. O filhote foi sensível a metadona, mas necessitou de alta dose de propofol para indução anestésica. A utilização de metadona como agente pré-anestésico e a infusão de remifentanil promoveram analgesia adequada baseado nos parâmetros avaliados. Keywords: xenotransfusion, stabilization, anesthesia, neonatal. Palavras-chave: xenotransfusão, estabilização, anestesia, neonato

Osteoprogenitor cells can enhance early bone formation in critical bone defects in dogs

<div><p>ABSTRACT: The aim of this study was to evaluate the effect of osteoprogenitor cells derived from mesenchymal stem cells from adipose tissue (OC-AD-MSCs), and differentiated into osteoblasts, in the treatment of critical bone defects in dogs. Adipose tissue derived mesenchymal stem cells (AD-MSCs) were subjected to osteogenic differentiation for 21 days and used in the treatment of bone defects in dogs radius. Either three experimental groups were bone defects treated with OC-AD-MSCs (OC), defects filled with autogenous bone (Control- C +), or empty defects (Control- C -). Bone regeneration was assessed by radiology, densitometry, and histomorphometry. The area of new bone formation was higher in the OC group compared to the control group (C-) on postoperative day 15. Defects treated with OC-AD-MSCs showed greater neovascularization than the other two groups at 90 days. We concluded that treatment with OC-AD-MSCs increased the area of new bone formation 15 days after surgery; however, it didn’t complete the bone union in critical bone defects in the radius of dogs at 90 days.</p></div