Clinical Application of the Fluid Challenge Approach in Goal-Directed Fluid Therapy: What Can We Learn From Human Studies?

Resuscitative fluid therapy aims to increase stroke volume (SV) and cardiac output (CO) and restore/improve tissue oxygen delivery in patients with circulatory failure. In individualized goal-directed fluid therapy (GDFT), fluids are titrated based on the assessment of responsiveness status (i.e., the ability of an individual to increase SV and CO in response to volume expansion). Fluid administration may increase venous return, SV and CO, but these effects may not be predictable in the clinical setting. The fluid challenge (FC) approach, which consists on the intravenous administration of small aliquots of fluids, over a relatively short period of time, to test if a patient has a preload reserve (i.e., the relative position on the Frank-Starling curve), has been used to guide fluid administration in critically ill humans. In responders to volume expansion (defined as individuals where SV or CO increases ≥10-15% from pre FC values), FC administration is repeated until the individual no longer presents a preload reserve (i.e., until increases in SV or CO are <10-15% from values preceding each FC) or until other signs of shock are resolved (e.g., hypotension). Even with the most recent technological developments, reliable and practical measurement of the response variable (SV or CO changes induced by a FC) has posed a challenge in GDFT. Among the methods used to evaluate fluid responsiveness in the human medical field, measurement of aortic flow velocity time integral by point-of-care echocardiography has been implemented as a surrogate of SV changes induced by a FC and seems a promising non-invasive tool to guide FC administration in animals with signs of circulatory failure. This narrative review discusses the development of GDFT based on the FC approach and the response variables used to assess fluid responsiveness status in humans and animals, aiming to open new perspectives on the application of this concept to the veterinary field.

Measurement of anesthetic pollution in veterinary operating rooms for small animals: Isoflurane pollution in a university veterinary hospital.

INTRODUCTION: Inhaled anesthetics are used worldwide for anesthesia maintenance both in human and veterinary operating rooms. High concentrations of waste anesthetic gases can lead to health risks for the professionals exposed. Considering that anesthetic pollution in a veterinary surgical center in developing countries is unknown, this study aimed, for the first time, to measure the residual concentration of isoflurane in the air of operating rooms for small animals in a Brazilian university hospital. METHOD: Residual isoflurane concentrations were measured by an infrared analyzer at the following sites: corner opposite to anesthesia machine; breathing zones of the surgeon, anesthesiologist, and patient (animal); and in front of the anesthesia machine at three time points, that is, 5, 30 and 120 minutes after anesthesia induction. RESULTS: Mean residual isoflurane concentrations gradually increased in the corner opposite to anesthesia machine and in the breathing zones of the surgeon and the anesthesiologist (p <  0.05). There was an increase at 30 minutes and 120 minutes when compared to the initial time points in the animal's breathing zone, and in the front of the anesthesia machine (p <  0.05). There was no significant difference at measurement sites regardless of the moment of assessment. CONCLUSION: This study reported high residual isoflurane concentrations in veterinary operating rooms without an exhaust system, which exceeds the limit recommended by an international agency. Based on our findings, there is urgent need to implement exhaust systems to reduce anesthetic pollution and decrease occupational exposure.

Dexmedetomidine-tiletamine-zolazepam followed by inhalant anesthesia in spectacled bears (Tremarctos ornatus)

Background: The spectacled bear (Tremarctos ornatus) is the only bear species inhabiting South America and is classified as vulnerable according to the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. Among the few publications on the use of general anesthesia and advanced monitoring of ursids in veterinary hospital settings, little is described regarding chemical restraint, general anesthesia and monitoring of spectacled bears. This case series describes the use of a dexmedetomidine-tiletamine-zolazepam chemical restraint combination and its effects on cardiorespiratory variables and arterial blood gases observed in two spectacled bears undergoing isoflurane anesthesia for imaging and/or surgical procedures. Cases: Two female, one adult and one senile, all-term captive spectacled bears were referred to the Veterinary Teaching Hospital at the Universidade Estadual Paulista - Unesp, Botucatu campus, both with a presumable history of recent trauma. After immobilization with an intramuscular (IM) administration of tiletamine-zolazepam (3.8 - 4.3 mg/kg) and dexmedetomidine (6.4 - 7.6 µg/kg), induction of anesthesia was achieved by means of intravenous (IV) propofol (1 - 2 mg/kg). After orotracheal intubation animals underwent isoflurane anesthesia under mechanical ventilation through the remainder of the procedures. Initial settings of inspiratory flow rate were adjusted to obtain peak airway pressure (Ppeak ) of 10 cmH2 O and tidal volumes (Vt) of 10 mL/kg, as well as respiratory rates (ƒR) and inspiration-to-expiration (I:E) ratio of 10 breaths/min and 1:2, respectively, and were then adjusted throughout anesthesia to maintain normocapnia (end-tidal carbon dioxide concentrations between 35 and 45 mmHg). One of the individuals was chemically restrained (6.4 mg/kg of tiletaminezolazepam and 7.7 µg/kg of dexmedetomidine) on a second anesthetic event for imaging...

Effects of whole-body vibration in hematobiochemical and hemogasometric parameters in adult and elderly healthy dogs

Background: Whole-Body Vibration (WBV) consists of mechanical vibration stimuli produced that propagate throughout the body by increasing the gravitational load. The WBV can increase muscle mass in dogs with muscular atrophy. As Whole-body vibration (WBV) can be used as exercise modality with no impact on the joints, the present study aimed to evaluate the effects of single session of WBV in hematobiochemical and hemogasometric parameters in adult and elderly healthy dogs. Materials, Methods & Results: Fourteen clinically healthy, neutered crossbreed male dogs, non-athlete were selected. The dogs were divided into two groups of seven dogs, according to the age group: Group I - adult dogs (GI): age between 12.0 and 84.0 months old; Group II - elderly dogs (GII): age above 84.0 months old. All dogs were submitted to a single session WBV by using a vibrating platform that delivered a vortex wave circulation as mechanical vibration. The WBV protocol used was 30 Hz frequency (3.10 mm peak displacement; 11.16 m/s2 peak acceleration; 0.29 m/s velocity), then 50 Hz (3.98 mm peak displacement; 39.75 m/s2 peak acceleration; 0.62 m/s velocity), and lastly 30 Hz (3.10 mm peak displacement; 11.16 m/s2 peak acceleration; 0.29 m/s velocity) for 5-min between de frequencies. The hematobiochemical and hemagasometric parameters were evaluated at 1-min before the WBV session (1PRE), 1-min after the WBV session (1POST), 120-min (120POST) and 24 h after the WBV session (24hPOST). The dogs accepted the vibration stimulus quite well, however, elderly dogs weighing above 30 kg were more likely to sit down with increased frequency from 30 to 50 Hz. No variations of food and water intakes and gastrointestinal changes were observed after the WBV session. Hemoglobin values showed significant decrease (P = 0.0312) between 1PRE and 1POST in elderly dogs. A significant decrease (P = 0.0453) was observed in alanine aminotransferase values between 120POST...

Manejo anestésico de um lobo-guará (Chrysocyon brachyurus) criticamente enfermo para amputação de membro pélvico / Anesthetic management of a maned wolf (Chrysocyon brachyurus) under critical condition for pelvic limb amputation

Background: The maned wolf (Chrysocyon brachyurus) is the largest south american canid and deemed a near threatenedspecies according to the International Union for Conservation of Nature (IUCN). Typically found in Brazilian Cerrado, it isoften a victim of animal trappings and vehicular accidents, where it may get deeply injured or end up fractured, demandingorthopedic procedures. Even though maned wolves are similar to the domestic dog, little is described regarding generalanesthesia and its complications for major procedures in ill patients in the scientific database. This case report describesa successful blood transfusion and anesthetic management of a critically ill C. brachyurus.Case: An adult female maned wolf was rescued after getting steel-jaw trapped. After chemical restraint with intramuscular(IM) ketamine (12 mg/kg), midazolam (0.3 mg/kg) and methadone (0.3 mg/kg), physical examination showed exposedbones to the distal end of the right hind limb, pronounced dehydration and moderate anemia and thrombocytopenia according to blood count. Radiographic images enlightened multiple right tarsus fractures. As the wound was highly infected,which made the osteosynthesis procedure impossible, it was decided to amputate the limb on the following day. Subcutaneous (SC) lactated Ringers solution (250 mL), IM meloxicam (0.2 mg/kg) and IM enrofloxacin (10 mg/kg) were alsoadministered at first. On the following day, after aforementioned chemical immobilization, anesthesia was induced withdose-effect intravenous (IV) propofol (2 mg/kg) until orotracheal intubation was possible, and general anesthesia wasmaintained with isoflurane diluted in oxygen. Lumbosacral epidural anesthesia was obtained with 0.5% bupivacaine (0.25mL/kg) and morphine (0.1 mg/kg) to provide analgesia and to reduce inhalant agent...(AU)

Manejo anestésico de um lobo-guará (Chrysocyon brachyurus) criticamente enfermo para amputação de membro pélvico / Anesthetic management of a maned wolf (Chrysocyon brachyurus) under critical condition for pelvic limb amputation

Background: The maned wolf (Chrysocyon brachyurus) is the largest south american canid and deemed a near threatenedspecies according to the International Union for Conservation of Nature (IUCN). Typically found in Brazilian Cerrado, it isoften a victim of animal trappings and vehicular accidents, where it may get deeply injured or end up fractured, demandingorthopedic procedures. Even though maned wolves are similar to the domestic dog, little is described regarding generalanesthesia and its complications for major procedures in ill patients in the scientific database. This case report describesa successful blood transfusion and anesthetic management of a critically ill C. brachyurus.Case: An adult female maned wolf was rescued after getting steel-jaw trapped. After chemical restraint with intramuscular(IM) ketamine (12 mg/kg), midazolam (0.3 mg/kg) and methadone (0.3 mg/kg), physical examination showed exposedbones to the distal end of the right hind limb, pronounced dehydration and moderate anemia and thrombocytopenia according to blood count. Radiographic images enlightened multiple right tarsus fractures. As the wound was highly infected,which made the osteosynthesis procedure impossible, it was decided to amputate the limb on the following day. Subcutaneous (SC) lactated Ringer’s solution (250 mL), IM meloxicam (0.2 mg/kg) and IM enrofloxacin (10 mg/kg) were alsoadministered at first. On the following day, after aforementioned chemical immobilization, anesthesia was induced withdose-effect intravenous (IV) propofol (2 mg/kg) until orotracheal intubation was possible, and general anesthesia wasmaintained with isoflurane diluted in oxygen. Lumbosacral epidural anesthesia was obtained with 0.5% bupivacaine (0.25mL/kg) and morphine (0.1 mg/kg) to provide analgesia and to reduce inhalant agent...

Acute Lung Injury Syndrome (TRALI) in a dog possibly triggered by blood transfusion

Background: Acute Lung Injury (ALI) and the Acute Respiratory Distress Syndrome (ARDS) are clinical syndromes, differing in severity, characterized by bilateral noncardiogenic pulmonary edema, usually associated with an underlying cause. Diagnosis is given by thoracic radiography and PaO2 /FiO2 ratio <300. The possible Transfusion Related Acute Lung Injury (TRALI) occurs when ALI or ARDS signs (i.e. hypoxemia and bilateral pulmonary infiltrates) are found in patients without preexisting ALI that have received transfusion in the last 72 h. This case report describes a case of a canine patient that developed possible TRALI after a forelimb amputation and a whole blood transfusion.Case: A 10-year-old female dog, with necrotic and infected bite injuries on left forelimb was initially treated conservatively with topical and systemics antibiotics. Eventually, a forelimb amputation was required, due to the soft tissue necrosis. Pre-operative complete blood count, serum biochemistry and venous blood gas analysis showed mild changes, including anemia, leukocytosis, metabolic acidosis, and increases in blood urea nitrogen, alkaline phosphatase, alanine transaminase. The patient was stable before surgery but required a post-operative whole blood transfusion to treat severe anemia. A crossmatch test was performed to reduce the possibility of transfusion reaction. Despite both surgery and hemotherapy went as expected, approximately eight hours after the transfusion, the patient developed deterioration of all vital signs, including hypotension and severe hypoxemia, with PaO2 /FiO2 <126 and oxyhemoglobin saturation (SpO2) < 90% on room air. Thoracic radiographies showed mixed pattern of bilateral pulmonary infiltration. The patients condition worsened with signs of respiratory failure, cyanosis and severe hemodynamic impairment. There was no improvement after administration of furosemide, hydrocortisone, vasoactives, supplemental oxygen and mechanical ventilation.[...](AU)

Hypotension aggravated by dopamine in a dog under isoflurane anesthesia

Background: Hypotension (MAP < 60 mmHg) is the most common complication in anesthetic practice and has been identified in 38% of canine patients undergoing general anesthesia for variety of procedures. Normalization of arterial pressure can usually be achieved by decreases in inhalant anesthetic concentrations, fluid administration, and use of inotropes/ vasopressors in healthy animals (ASA I) or animals with mild systemic disease (ASA anesthetic risk II). The present report shows an ASA II dog with severe hypotensive crisis [mean arterial pressure (MAP) < 50 mmHg] during general anesthesia, in which the procedure was aborted because hypotension was aggravated by dopamine.Case: A 7-year-old male Bull Terrier was anesthetized for magnetic resonance imaging (MRI) of a tumor in the face. After intramuscular acepromazine (0.01 mg/kg) and meperidine (3 mg/kg), anesthesia was induced with intravenous (IV) ketamine (1 mg/kg) and propofol (2.3 mg/kg) and maintained with isoflurane in oxygen. Ten min after induction of anesthesia MAP was 45 mmHg, while end-tidal isoflurane (ETISO) concentration was 0.5%. End-tidal isoflurane was decreased to 0.3% and an IV bolus of Lactated Ringers was initiated (15 mL/kg over 10 min), followed by two ephedrine boluses (0.1 mg/kg, IV) administered 5 min apart. MAP remained low (< 50 mmHg) and dopamine constant rate infusion (CRI) was initiated (7.5 μg/kg/min). Ten minutes after dopamine CRI was commenced, MAP was further decreased to 25-22 mmHg. Dopamine CRI was increased to 10 μg/kg/min, but MAP remained < 25 mmHg. Infusion drugs and isoflurane anesthesia were stopped. After the animal was extubated MAP returned 60-70 mmHg.Discussion: Among the drugs used, isoflurane is known for decreasing blood pressure in a dose-related manner because of its vasodilating properties.[...](AU)

Hypotension aggravated by dopamine in a dog under isoflurane anesthesia

Background: Hypotension (MAP < 60 mmHg) is the most common complication in anesthetic practice and has been identified in 38% of canine patients undergoing general anesthesia for variety of procedures. Normalization of arterial pressure can usually be achieved by decreases in inhalant anesthetic concentrations, fluid administration, and use of inotropes/ vasopressors in healthy animals (ASA I) or animals with mild systemic disease (ASA anesthetic risk II). The present report shows an ASA II dog with severe hypotensive crisis [mean arterial pressure (MAP) < 50 mmHg] during general anesthesia, in which the procedure was aborted because hypotension was aggravated by dopamine.Case: A 7-year-old male Bull Terrier was anesthetized for magnetic resonance imaging (MRI) of a tumor in the face. After intramuscular acepromazine (0.01 mg/kg) and meperidine (3 mg/kg), anesthesia was induced with intravenous (IV) ketamine (1 mg/kg) and propofol (2.3 mg/kg) and maintained with isoflurane in oxygen. Ten min after induction of anesthesia MAP was 45 mmHg, while end-tidal isoflurane (ETISO) concentration was 0.5%. End-tidal isoflurane was decreased to 0.3% and an IV bolus of Lactated Ringer’s was initiated (15 mL/kg over 10 min), followed by two ephedrine boluses (0.1 mg/kg, IV) administered 5 min apart. MAP remained low (< 50 mmHg) and dopamine constant rate infusion (CRI) was initiated (7.5 μg/kg/min). Ten minutes after dopamine CRI was commenced, MAP was further decreased to 25-22 mmHg. Dopamine CRI was increased to 10 μg/kg/min, but MAP remained < 25 mmHg. Infusion drugs and isoflurane anesthesia were stopped. After the animal was extubated MAP returned 60-70 mmHg.Discussion: Among the drugs used, isoflurane is known for decreasing blood pressure in a dose-related manner because of its vasodilating properties.[...]

Acute Lung Injury Syndrome (TRALI) in a dog possibly triggered by blood transfusion

Background: Acute Lung Injury (ALI) and the Acute Respiratory Distress Syndrome (ARDS) are clinical syndromes, differing in severity, characterized by bilateral noncardiogenic pulmonary edema, usually associated with an underlying cause. Diagnosis is given by thoracic radiography and PaO2 /FiO2 ratio <300. The possible Transfusion Related Acute Lung Injury (TRALI) occurs when ALI or ARDS signs (i.e. hypoxemia and bilateral pulmonary infiltrates) are found in patients without preexisting ALI that have received transfusion in the last 72 h. This case report describes a case of a canine patient that developed possible TRALI after a forelimb amputation and a whole blood transfusion.Case: A 10-year-old female dog, with necrotic and infected bite injuries on left forelimb was initially treated conservatively with topical and systemics antibiotics. Eventually, a forelimb amputation was required, due to the soft tissue necrosis. Pre-operative complete blood count, serum biochemistry and venous blood gas analysis showed mild changes, including anemia, leukocytosis, metabolic acidosis, and increases in blood urea nitrogen, alkaline phosphatase, alanine transaminase. The patient was stable before surgery but required a post-operative whole blood transfusion to treat severe anemia. A crossmatch test was performed to reduce the possibility of transfusion reaction. Despite both surgery and hemotherapy went as expected, approximately eight hours after the transfusion, the patient developed deterioration of all vital signs, including hypotension and severe hypoxemia, with PaO2 /FiO2 <126 and oxyhemoglobin saturation (SpO2) < 90% on room air. Thoracic radiographies showed mixed pattern of bilateral pulmonary infiltration. The patient’s condition worsened with signs of respiratory failure, cyanosis and severe hemodynamic impairment. There was no improvement after administration of furosemide, hydrocortisone, vasoactives, supplemental oxygen and mechanical ventilation.[...]

Acurácia dos métodos oscilométrico (PETMAP®) e doppler para aferição indireta da pressão arterial em cordeiros / Accuracy of oscillometric (PETMAP) and doppler methods to indirect measurement of blood pressure in lambs

Neonatal physiology has peculiarities inherent to the age group. The objective of this study was to monitor the systemic arterial pressure in lambs during neonatal period. We used 20 Ile de France lambs, from birth and at 7, 14, 21, 28 and 35 days of life. The following parameters were analyzed: heart rate (HR), systolic (SBP), diastolic (DBP), and average blood pressure (ABP) by oscillometric method petMAP, and SBP with Doppler. Invasive pressure validated indirect methods with the average 101.52 ± 12.04 mmHg. The averages with petMAP were as follows: HR (156.38 ± 37.46 bpm); DBP (63.80 ± 11.14 mmHg); ABP (81.58 ± 11.83 mmHg); SBP (112.48 ± 15.68 mmHg) and SBP by Dobler (90.27 ± 12.11 mmHg). There was significant difference in HR and blood pressure among the moments. Indirect methods differ between each other in 12.30 mmHg (overestimation   of 11%). Comparing with the invasive methods, both overestimated values of 4% and 16% in   PAS, respectively, for Doppler and petMAP. The results showed that the Doppler method has established a good relationship with the invasive one being useful for gauging the SBP. The oscillometric method requires larger studies to be used in small ruminants.

A fisiologia neonatal possui peculiaridades inerentes à faixa etária. O objetivo do estudo foi monitorar a pressão arterial sistêmica de cordeiros durante o período neonatal. Foram usados 20 cordeiros da raça Ile de France, a partir do nascimento e aos sete, 14, 21, 28 e 35 dias de vida. Os parâmetros analisados foram: frequência cardíaca (FC), pressão arterial sistólica (PAS), diastólica (PAD) e média (PAM) pelo método oscilométrico petMAP®, e PAS com Doppler. Também foi realizada a pressão invasiva para validar os métodos indiretos obtendo a média de 101,52 ± 12,04 mmHg. As médias utilizando o petMAP® foram: FC (156,38 ± 37,46 bpm); PAD (63,80 ± 11,14 mmHg); PAM   (81,58± 11,83 mmHg); PAS (112,48 ±15,68 mmHg) e PAS (90,27 ± 12,11 mmHg) com Doppler. Houve diferença significativa na FC e pressão arterial entre os momentos analisados. Os métodos indiretos diferiram entre si em 12,30 mmHg (superestimação de 11%). Comparando com a invasiva, os dois métodos superestimaram os valores da PAS em 4% e 16%, respectivamente, para Doppler e petMAP®. Os resultados mostraram que o método Doppler estabeleceu boa relação com a invasiva, sendo útil para aferição da PAS. O método oscilométrico necessita de maiores estudos para sua utilização em pequenos ruminantes.

Acurácia dos métodos oscilométrico (PETMAP®) e doppler para aferição indireta da pressão arterial em cordeiros / Accuracy of oscillometric (PETMAP) and doppler methods to indirect measurement of blood pressure in lambs

Neonatal physiology has peculiarities inherent to the age group. The objective of this study was to monitor the systemic arterial pressure in lambs during neonatal period. We used 20 Ile de France lambs, from birth and at 7, 14, 21, 28 and 35 days of life. The following parameters were analyzed: heart rate (HR), systolic (SBP), diastolic (DBP), and average blood pressure (ABP) by oscillometric method petMAP, and SBP with Doppler. Invasive pressure validated indirect methods with the average 101.52 ± 12.04 mmHg. The averages with petMAP were as follows: HR (156.38 ± 37.46 bpm); DBP (63.80 ± 11.14 mmHg); ABP (81.58 ± 11.83 mmHg); SBP (112.48 ± 15.68 mmHg) and SBP by Dobler (90.27 ± 12.11 mmHg). There was significant difference in HR and blood pressure among the moments. Indirect methods differ between each other in 12.30 mmHg (overestimation   of 11%). Comparing with the invasive methods, both overestimated values of 4% and 16% in   PAS, respectively, for Doppler and petMAP. The results showed that the Doppler method has established a good relationship with the invasive one being useful for gauging the SBP. The oscillometric method requires larger studies to be used in small ruminants.(AU)

A fisiologia neonatal possui peculiaridades inerentes à faixa etária. O objetivo do estudo foi monitorar a pressão arterial sistêmica de cordeiros durante o período neonatal. Foram usados 20 cordeiros da raça Ile de France, a partir do nascimento e aos sete, 14, 21, 28 e 35 dias de vida. Os parâmetros analisados foram: frequência cardíaca (FC), pressão arterial sistólica (PAS), diastólica (PAD) e média (PAM) pelo método oscilométrico petMAP®, e PAS com Doppler. Também foi realizada a pressão invasiva para validar os métodos indiretos obtendo a média de 101,52 ± 12,04 mmHg. As médias utilizando o petMAP® foram: FC (156,38 ± 37,46 bpm); PAD (63,80 ± 11,14 mmHg); PAM   (81,58± 11,83 mmHg); PAS (112,48 ±15,68 mmHg) e PAS (90,27 ± 12,11 mmHg) com Doppler. Houve diferença significativa na FC e pressão arterial entre os momentos analisados. Os métodos indiretos diferiram entre si em 12,30 mmHg (superestimação de 11%). Comparando com a invasiva, os dois métodos superestimaram os valores da PAS em 4% e 16%, respectivamente, para Doppler e petMAP®. Os resultados mostraram que o método Doppler estabeleceu boa relação com a invasiva, sendo útil para aferição da PAS. O método oscilométrico necessita de maiores estudos para sua utilização em pequenos ruminantes.(AU)

ACURÁCIA DOS MÉTODOS OSCILOMÉTRICO (PETMAP®) E DOPPLER PARA AFERIÇÃO INDIRETA DA PRESSÃO ARTERIAL EM CORDEIROS

Abstract Neonatal physiology has peculiarities inherent to the age group. The objective of this study was to monitor the systemic arterial pressure in lambs during neonatal period. We used 20 Ile de France lambs, from birth and at 7, 14, 21, 28 and 35 days of life. The following parameters were analyzed: heart rate (HR), systolic (SBP), diastolic (DBP), and average blood pressure (ABP) by oscillometric method petMAPTM, and SBP with Doppler. Invasive pressure validated indirect methods with the average 101.52 ± 12.04 mmHg. The averages with petMAPTM were as follows: HR (156.38 ± 37.46 bpm); DBP (63.80 ± 11.14 mmHg); ABP (81.58 ± 11.83 mmHg); SBP (112.48 ± 15.68 mmHg) and SBP by Dobler (90.27 ± 12.11 mmHg). There was significant difference in HR and blood pressure among the moments. Indirect methods differ between each other in 12.30 mmHg (overestimation of 11%). Comparing with the invasive methods, both overestimated values of 4% and 16% in PAS, respectively, for Doppler and petMAPTM. The results showed that the Doppler method has established a good relationship with the invasive one being useful for gauging the SBP. The oscillometric method requires larger studies to be used in small ruminants.

Resumo A fisiologia neonatal possui peculiaridades inerentes à faixa etária. O objetivo do estudo foi monitorar a pressão arterial sistêmica de cordeiros durante o período neonatal. Foram usados 20 cordeiros da raça Ile de France, a partir do nascimento e aos sete, 14, 21, 28 e 35 dias de vida. Os parâmetros analisados foram: frequência cardíaca (FC), pressão arterial sistólica (PAS), diastólica (PAD) e média (PAM) pelo método oscilométrico petMAP®, e PAS com Doppler. Também foi realizada a pressão invasiva para validar os métodos indiretos obtendo a média de 101,52 ± 12,04 mmHg. As médias utilizando o petMAP® foram: FC (156,38 ± 37,46 bpm); PAD (63,80 ± 11,14 mmHg); PAM (81,58 ± 11,83 mmHg); PAS (112,48 ±15,68 mmHg) e PAS (90,27 ± 12,11 mmHg) com Doppler. Houve diferença significativa na FC e pressão arterial entre os momentos analisados. Os métodos indiretos diferiram entre si em 12,30 mmHg (superestimação de 11%). Comparando com a invasiva, os dois métodos superestimaram os valores da PAS em 4% e 16%, respectivamente, para Doppler e petMAP®. Os resultados mostraram que o método Doppler estabeleceu boa relação com a invasiva, sendo útil para aferição da PAS. O método oscilométrico necessita de maiores estudos para sua utilização em pequenos ruminantes.

Adrenomedullin induces pulmonary vasodilation but does not attenuate pulmonary hypertension in a sheep model of acute pulmonary embolism.

AIMS: The pulmonary vasodilation induced by adrenomedullin may be beneficial in the acute pulmonary embolism (APE) setting. This study examined effects of adrenomedullin in sheep with microsphere-induced APE. MAIN METHODS: Twenty four anesthetized, mechanically ventilated sheep were randomly assigned into 3 groups (n=8 per group): animals not subjected to any intervention (Sham), animals with APE induced by microspheres (500 mg, intravenously) treated 30 min later by intravenous physiological saline (Emb group) or intravenous adrenomedullin (50 ng/kg/min) during 30 min (Emb+Adm group). Plasma concentrations of cyclic adenosine (cAMP) and guanosine monophosphate (cGMP) were determined by enzyme immunoassay. KEY FINDINGS: Variables did not change over time in sham animals. In both embolized groups, microsphere injection significantly (P<0.05) increased pulmonary vascular resistance index (PVRI) and mean pulmonary artery pressure (MPAP) from baseline by 181% and 111-142%, respectively (% change in mean values). Adrenomedullin significantly decreased PVRI (18%-25%) and significantly increased cardiac index (22%-25%) from values recorded 30 min after APE (E30), without modifying MPAP. Adrenomedullin decreased mean arterial pressure (18%-24%) and systemic vascular resistance index (32%-40%). Embolization significantly increased arterial-to-end tidal CO2 gradient, alveolar-to-arterial O2 gradient, and pulmonary shunt fraction from baseline, but these variables were unaffected by adrenomedullin. While adrenomedullin significantly increased plasma cAMP, cGMP levels were unaltered. SIGNIFICANCE: Adrenomedullin induces systemic and pulmonary vasodilation, possibly via a cAMP mediated mechanism, without modifying the gas exchange impairment associated with APE. The pulmonary anti-hypertensive effect of adrenomedullin may be offset by increases in cardiac index.

Effects of different inspired oxygen fractions on sildenafil-induced pulmonary anti-hypertensive effects in a sheep model of acute pulmonary embolism.

AIMS: Sildenafil is a pulmonary anti-hypertensive agent whose action could be modified by different fractions of inspired oxygen (FiO2). We compared the effects of pure oxygen (FiO2 > 90%) or room air (21% FiO2) on the cardiopulmonary actions of sildenafil in sheep with acute pulmonary embolism (APE). MAIN METHODS: Thirty-two anesthetized, mechanically ventilated sheep (34.9 ± 5.4 kg), were randomly distributed into four groups (n = 8 per group): FiO2 > 90% without intervention; APE induced by microspheres with FiO2 > 90%, followed 30 min later by placebo (Emb90); or APE followed 30 min later by intravenous sildenafil (0.7 mg/kg over 30 min) with FiO2 > 90% (Emb + Sild90) or 21% FiO2 (Emb + Sild21) [Corrected]. Variables were recorded until 30 min after the end of treatment administration. KEY FINDINGS: Microsphere injection increased (P < 0.05) mean pulmonary artery pressure (MPAP) in all embolized groups (111-140% higher than that of baseline). Compared with values recorded 30 min after induction of APE (E30), sildenafil induced greater decreases in MPAP in the Emb + Sil90 group than in the Emb + Sil21 group (23% and 14% lower than E30, respectively). Hypotension (mean arterial pressure < 60 mm Hg) was precipitated by sildenafil due to systemic vasodilation in the Emb + Sil21 group. Embolization lowered the PaO2/FiO2 ratio and increased venous admixture, but sildenafil did not alter the oxygenation impairment induced by APE. SIGNIFICANCE: Sildenafil induces a more consistent pulmonary anti-hypertensive effect and causes less interference with the systemic circulation with the concomitant use of pure oxygen than that with room air in the APE setting.

Diagnóstico e tratamento de choque séptico em cães / Diagnoses and treatment of septic shock in dogs

O choque séptico é uma das síndromes mais frequentes na clínica de pequenos animais. Esta síndromeé associada a altas taxas de mortalidade e pode ocorrer como a evolução de qualquer patologia, seja elade natureza infecciosa ou não. Apresenta duas fases, sendo a fase precoce chamada de hiperdinâmica,que apesar de muitas vezes não diagnosticada, possui melhor prognóstico, evoluindo para a fase hipodinâmica,caracterizada por hipotensão irresponsiva a vasopressores e inotrópicos, progredindo para asíndrome da disfunção múltipla de órgãos, e culminando em óbito. O objetivo desta revisão foi reunirinformações para um diagnóstico e tratamento desta síndrome, visando assim aumentar a taxa de sobrevidados pacientes acometidos.

Septic shock is one of the most common syndromes observed in small animal practice. This syndromeresults in high mortality rates and may occur as a consequence of any disease state caused by infectiousor noninfectious processes. The septic shock is presented with 2 phases, the initial stage, which carriesa better prognosis, is named hyperdynamic phase; the later stage (hypodynamic phase) is characterizedby hypotension that is not responsive to vasopressors and inotropes, progressing to multiple organ dysfunction,and death. This literature review aimed to provide an update on the diagnosis and treatment ofthis condition, in order to provide the clinician with the latest information on how to reduce the mortalityassociated with this syndrome.

Diagnóstico e tratamento de choque séptico em cães / Diagnoses and treatment of septic shock in dogs

O choque séptico é uma das síndromes mais frequentes na clínica de pequenos animais. Esta síndromeé associada a altas taxas de mortalidade e pode ocorrer como a evolução de qualquer patologia, seja elade natureza infecciosa ou não. Apresenta duas fases, sendo a fase precoce chamada de hiperdinâmica,que apesar de muitas vezes não diagnosticada, possui melhor prognóstico, evoluindo para a fase hipodinâmica,caracterizada por hipotensão irresponsiva a vasopressores e inotrópicos, progredindo para asíndrome da disfunção múltipla de órgãos, e culminando em óbito. O objetivo desta revisão foi reunirinformações para um diagnóstico e tratamento desta síndrome, visando assim aumentar a taxa de sobrevidados pacientes acometidos.(AU)

Septic shock is one of the most common syndromes observed in small animal practice. This syndromeresults in high mortality rates and may occur as a consequence of any disease state caused by infectiousor noninfectious processes. The septic shock is presented with 2 phases, the initial stage, which carriesa better prognosis, is named hyperdynamic phase; the later stage (hypodynamic phase) is characterizedby hypotension that is not responsive to vasopressors and inotropes, progressing to multiple organ dysfunction,and death. This literature review aimed to provide an update on the diagnosis and treatment ofthis condition, in order to provide the clinician with the latest information on how to reduce the mortalityassociated with this syndrome.(AU)

Efeito de drogas utilizadas no tratamento de hipertensäo arterial sistêmica sobre a pressäo intra-ocular: estudo experimental no cäo / Effects of drugs used in the treatment of systemic arterial hypertension on intraocular pressure: experimental study in dogs

Objetivo: Estudar os efeitos de duas drogas utilizadas no tratamento de hipertensäo arterial sistêmica (captopril e propranolol) sobre a pressäo intra-ocular (PIO) e pressäo de perfusäo (PP) em cäes anestesiados. Métodos: Foram estudados 24 cäes, divididos em 3 grupos de 8. No primeiro grupo (GI), foi administrado captopril (um inibidor da enzima conversora de angiotensina) na dose de 1,5 mg/kg por via endovenosa. No segundo grupo (GII), foi administrado propranolol (um beta-bloqueador) na dose de 1,5 mg/kg por via endovenosa. O terceiro grupo (GIII) foi o grupo controle. A PIO e a pressäo arterial média (PAm) foram medidas por manometria. A pressäo de perfusäo (PP) foi calculada pela diferença entre a PAm e a PIO. A freqüência cardíaca (FC) foi monitorada com oxímetro de pulso. Os parâmetros foram estudados em 6 momentos (0,10, 30, 60,90 e 120 minutos). Resultados: Houve reduçäo estatisticamente significativa da PIO(p<0,05) nos grupos em que foram administrados captopril e propranolol, sem diferença entre as drogas. Com captopril, houve reduçäo da PAm e da PP aos 10 e 30 minutos. Com propranolol, näo houve reduçäo da PAm ou da PP. Conclusäo: Houve reduçäo da PIO com uso do captopril e também do propranolol. Entretanto, a reduçäo acentuada da PAm e da PP causadas pelo captopril, podem ser indesejáveis para a irrigaçäo do nervo óptico.

Evaluation of the effect of hyoscine-N-butyl bromide on the cardiovascular actions of detomidine in the horse

Twenty one adult horses, males and females, were pretreated with 0.14 mg/kg of hyoscine-N-butylbromide intravenously and injected 5 minutes later with 0.02 mg/kg, iv of detomidine (group A, n = 9) or saline (group B, n = 12). Mean arterial pressure measurements and electrocardiography were performed during 65 minutes. After hyoscine injection the heart rate was increased by 43 percent and 65 percent in A and B groups, respectively. Heart rate remained increased after injection of detomidine, returning to baseline values after 15 minutes. No increase in the mean arterial pressure (MAP) was noticed after hyoscine but the MAP was increased by 62 percent after detomidine, returning to basal measurements until the end of observation time. No additional increase was noted in the group B horses. Hyoscine shortened PR and QT intervals in both groups, but after detomidine, PR and QT intervals enlarged significantly at the end of the experiment. The second degree atrioventricular block occurred in 3 horses after 40 minutes only in group B. It was concluded that hyoscine prevented detomidine induced bradycardia and may be an useful drug combination against the bradycardia induced by this alpha-2 agonist, in horses

Avaliação da associação midazolam/droperidol na tranqüilização de suínos / Evaluation of midazolam/droperidol association for tranquilization of swines

Na presente pesquisa, avaliou-se a associação midazolam/droperidol na tranqüilização de 11 suínos da raça Landrace. Foram analisadas as frequências cardíaca, respiratória, temperatura retal e hemogasimetria arterial antes e após a administração do midazolam (0,4mg/kg IM) associado ao droperidol (0,4mg/kg IM). As anotações paramétricas e análises hemogasimétricas foram realizadas a intervalos de 10 minutos, durante uma hora após a administração das drogas. Concomitantemente efetuaram-se observações clínicas a respeito da eficácia da tranqüilização. Não ocorreram alterações significativas nos parâmetros de frequência cardíaca e equilíbrio ácido-base. A frequência respiratória diminuiu significativamente, quando comparada aos valores basais. O tempo médio de ação das drogas foi de 60 minutos, com período de latência de 3 minutos. Durante a tranqüilização houve relaxamento muscular, perda dos reflexos posturais, indiferença ao meio ambiente e manutenção dos reflexos protetores. A análise dos resultados permite indicar a associação midazolam/droperidol para a tranqüilização/sedação de suínos.

The association midazolam/droperidol was evaluated in the chemical restraint of 11 Landrace swines. Cardiac and respiratory rates were studied as well as rectal temperature and blood gas analisis after and before the midazolam (0.4mg/kg)/droperidol (0.4mg/kg) injection. The parametrical values and the blood gas analisis were performed during an hour period after drug administration, at 10 minutes intervals. At the same time, clinical trials were performed about the effectiveness of the tranquilization. Significant changes did not occur in the heart rate and acid-basic equilibrium. The respiratory rate decreased significantly, when compared to basal measurements. The set time of the drug action was that of 60 minutes, with an onset period of 3 minutes. During the tranquilization it was observed muscle relief, loss of the postural reflexos, abscence to enviromental stimulus and keeping of the pain reflex. The analysis of the obtained results enables to indicate the midazolam/droperidol association for the tranquilization of swines.