Efeitos da infusão contínua de cetamina sobre a pressão intra-ocular em cães hipovolêmicos anestesiados com desflurano

Compararam-se os efeitos de duas doses de cetamina, administradas em infusão contínua, sobre a pressão intra-ocular (PIO) de 18 cães submetidos à hipovolemia e à anestesia com desflurano. Promoveu-se a hipovolemia em todos os cães, retirando-se 40 ml de sangue/kg de peso. A anestesia foi induzida com desflurano, através de máscara facial, até que a intubação orotraqueal fosse permitida. Decorridos 30 minutos, para estabilização dos parâmetros, iniciou-se a infusão contínua de cetamina. Os cães foram distribuídos, aleatoriamente, em três grupos (n= 6). O grupo I (controle) recebeu solução salina estéril; o grupo II (GII) recebeu cetamina, na dose de 100mig/kg/min, e o grupo III (GIII), cetamina na dose de 200mig/kg/min. A PIO foi medida por tonometria de aplanação. Foram mensurados freqüência cardíaca (FC), ritmo cardíaco, pressão arterial média (PAM), débito cardíaco (DC), pressão venosa central (PVC) e pressão parcial de CO2 no final da expiração (ETCO2). O desflurano não influenciou os resultados da PIO, porém observou-se discreta ação da cetamina em todos os grupos. Foi possível estabelecer relação direta entre os valores de PIO e de ETCO2. A PIO apresentou relação direta somente com a ETCO2.

Alterações hemodinâmicas e intracranianas em cães com hemorragia aguda, anestesiados com isofluorano

Estudaram-se possíveis alterações hemodinâmicas e intracranianas em cães submetidos à hemorragia aguda e anestesiados pelo isofluorano. Verificou-se também a influência do anestésico no mecanismo de auto-regulação cerebral. Utilizaram-se 20 cães adultos que foram induzidos à anestesia geral com isofluorano por máscara naso-oral a 3,5V% (volume %). Após a intubação orotraqueal, reajustou-se o vaporizador para 2,1V%. Induziu-se a hipovolemia retirando-se volume total de 35ml/kg de sangue. Avaliaram-se pressão intracraniana (PIC), temperaturas intracraniana (TIC) e corpórea (T), pressão de perfusão cerebral (PPC), pressões arteriais sistólica (PAS), diastólica (PAD) e média (PAM), freqüências cardíaca (FC) e respiratória (FR), índices cardíaco (IC) e sistólico (IS), pressão venosa central (PVC), pressão da artéria pulmonar (PAP), concentração de dióxido de carbono ao final da expiração (ETCO2) e saturação de oxihemoglobina (SpO2). Imediatamente após a hipovolemia, houve redução significativa da PIC, PPC, PAS, PAD, PAM, IC, IS e PAP. Após 10 minutos, houve aumento gradativo das médias, permanecendo neste patamar até o final do período experimental. Concluiu-se que a hemorragia aguda promoveu redução das variáveis hemodinâmicas, sendo possível verificar a ativação de mecanismos compensatórios. Além disso, houve redução da perfusão sangüínea e ativação do mecanismo de auto-regulação cerebral, conseqüentes à hipovolemia associada à anestesia com isofluorano.

Ventilação mandatória intermitente sincronizada versus ventilação com suporte pressórico e volume garantido em coelhos induzidos à hemorragia aguda

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação da buprenorfina pelas vias intravenosa ou intramuscular em cães anestesiados pelo desfluorano

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Alterações cardiovasculares e intracranianas promovidas pela buprenorfina em cães anestesiados com desflurano

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Propofol ou sevofluorano sobre variáveis hemodinâmicas em cães submetidos à administração subaracnóidea de iohexol

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeitos cardiovascular e metabólico da reposição volêmica com solução salina hipertônica 7,5% associada ou não ao hidroxietilamido 130/0,4 em gatas com hipovolemia induzida

A hipovolemia é caracterizada por uma perda de fluido corpóreo, cursando com inadequado fluxo circulatório e consequentemente lesão tecidual. Neste trabalho, objetivou-se comparar a expansão volêmica resultante da administração de solução salina hipertônica (NaCl 7,5%), isolada ou em associação com hidroxietilamido 130/0,4 (HES 130/0,4), em gatas com hipovolemia induzida, sob anestesia geral inalatória com isofluorano. Foram utilizadas 12 gatas, sem raça definida, adultas, com massa corporal média de 3,07±0,56kg. Os animais foram anestesiados com isofluorano e, após a preparação cirúrgica, foram mantidos em 1CAM sob ventilação controlada. Após a estabilização do plano anestésico, foram avaliados os parâmetros basais. em ato contínuo, iniciou-se a fase de hipovolemia, por meio da retirada de 30ml kg-1 de sangue da artéria femoral. Após 60 minutos da estabilização do quadro de hipovolemia, foi realizada nova mensuração dos dados, alocando-se os animais aleatoriamente em dois grupos: GSH (grupo solução hipertônica, n=6), que receberam, na fase de expansão volêmica, NaCl 7,5% isolada, na dose de 4ml kg-1, e GSHC (grupo salina hipertônica associado ao coloide, n=6), que receberam NaCl 7,5%, na mesma dose citada, em associação com HES 130/0,4, na dose de 30ml kg-1. Após realização do tratamento, foram avaliados novamente os efeitos cardiovasculares e hemogasométricos por 120 minutos. As pressões arteriais média (PAM), sistólica (PAS) e diastólica (PAD) foram maiores logo após a expansão volêmica (T0) para o GSH. de T45 até T120, as PAM, PAS e PAD foram maiores para o GSHC, em comparação com o GSH. A pressão venosa central foi maior no GSHC até T60. Não foram observadas diferenças entre grupos para frequência cardíaca e respiratória, íons sódio e potássio, déficit de base, bicarbonato, saturação de oxigênio na hemoglobina, glicose, PaCO2, PaO2 e pH. Conclui-se que a administração de NaCl 7,5% isoladamente aumenta rapidamente a PAM, PAS e PAD em gatos com hipovolemia induzida, mantendo esse efeito por apenas 30 minutos, enquanto que a administração de hidroxietilamido 130/0,4 associado à NaCl 7,5% promove reestabelecimento mais tardio (após 30 minutos), porém mais duradouro (até 120 minutos) da PAM, PAS e PAD em gatas com hipovolemia induzida. A administração de HES 130/0,4 associada à NaCl 7,5% promove aumento acentuado da PVC por até 60 minutos após a administração.

Utilization of peritoneal dialysis in the acute setting

Peritoneal dialysis (PD), although classically described and utilized in the treatment of patients with end-stage renal disease, can also be utilized in the acute setting in different clinical situations. Recent studies showed that, in patients with acute renal failure, it is possible to obtain reasonable dialysis doses with adequate metabolic and etectrolytic control and tow incidence of complications by utilizing continuous PD through a cycler at high volume. In patients with congestive heart failure without end-stage renal disease, PD is capable of promoting clinical improvement with slow removal of liquids, becoming an attractive alternative for situations of rapidly or slowly worsening cardiac function. In patients submitted to chronic hemodialysis but who have vascular access difficulties, PD can also be utilized as a bridge, thereby avoiding the use of central venous catheters, which can be associated with infectious complications such as bacterial endocarditis. New studies must be realized showing other indications for PD.

Evaluation of intraocular pressure in association with cardiovascular parameters in normocapnic dogs anesthetized with sevoflurane and desflurane

The objective of this study was to determine intraocular pressure (IOP) and cardiac changes in normocapnic dogs maintained under controlled ventilation and anesthetized using sevoflurane or desflurane. Sixteen healthy adult mixed-breed dogs, seven males and nine females, weighing 10-15 kg were used. The dogs were randomly assigned to one of two groups composed of eight animals anesthetized with sevoflurane (SEVO) or desflurane (DESF). In both groups, anesthesia was induced with propofol (10 mg/kg), and neuromuscular blockade was achieved with rocuronium (0.6 mg/kg/h IV). No premedication was given. Ventilation was adjusted to maintain end-tidal carbon dioxide partial pressure at 35 mmHg. Anesthesia was maintained with 1.5 minimum alveolar concentration (MAC) of sevoflurane or desflurane. In both groups IOP was measured by applanation tonometry (Tono-Pen) before induction of anesthesia. IOP, mean arterial pressure (MAP), heart rate (HR), cardiac index (CI) and central venous pressure (CVP) were also measured 45 min after the beginning of inhalant anesthesia and then every 20 min for 60 min. A one-way repeated measures ANOVA was used to compare data within the same group and Student's t-test was used to assess differences between groups. P < 0.05 was considered statistically significant. Measurements showed normal IOP values in both groups, even though IOP increased significantly from baseline during the use of desflurane. IOP did not differ between groups. CI in the desflurane group was significantly greater than in the sevoflurane group. Sevoflurane and desflurane have no clinically significant effects on IOP, MAP, HR, CI or VCP in the dog.

Effect of passive pneumoperitoneum on oesophageal pressure, cardiovascular parameters and blood gas analysis in horses

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

EFEITOS DA INFUSAO CONTINUA DO PROPOFOL SOBRE A FUNCAO RENAL DO CAO. ESTUDO COMPARATIVO COM O PENTOBARBITAL SODICO

Little research has been done with propofol in relation to renal function. The aim of this study was to evaluate the effects of the continuous infusion of propofol on renal function in dogs. Sixteen dogs, previously anesthetized with pentobarbital sodium (30 mg.kg-1) for surgical preparation, catheterism and monitoring, were studied. The dogs were mechanically ventilated with air and received alcuronium (0.2 mg.kg-1 in bolus and 0.06 mg.kg-1 - maintenance). The following parameters were studied: heart rate (HR), mean arterial pressure (MAP), central venous pressure (CVP), aortic blood flow (A(o)BF - by electromagnetic flowmeter installed in the ascending aortic), aortic vascular resistance index (A(o)VRI), renal plasma flow (ERPF - by para-aminohipurate clearance), glomerular filtration rate (GFR - by creatinine clearance), effective renal blood flow (ERBF = ERPF/1 - hematocrit), urinary volume (UV), renal vascular resistance (RVR = MAP.80/ERBF.10-3), urinary sodium excretion (UE(Na)), fractionated sodium excretion (FE(Na)), osmolar clearance (C(osm)) and free water clearance (C(H2O)). These parameters were studied at 15 (M1), 30 (M2), 45 (M3) and 60 (M4) min after beginning pentobarbital sodium infusion (5 mg.kg-1.h-1). The dogs were allocated into two groups of eight animals each: G1 (control-pentobarbital sodium) and G2 (propofol). In G1, pentobarbital was given at the four times studied. G2 dogs received the same treatment as G1 dogs at M1 and M2; infusion of pentobarbital was substituted by propofol (3 mg.kg-1 bolus, followed by 12 mg.kg-1.h-1 continuous infusion) at M3 and M4. Profile Analysis was used to analyze the results statistically. In G1 (pentobarbital), there was a significant increase in RVR (M1 < M4) and a decrease in ERPF and ERBF (M1 > M4). In G2 (propofol) there was only a significant increase in A(o)BF (M1 < M2 = M3). In comparison among groups, these was a significant alteration of FE(Na) at M3 (pentobarbital > propofol). It was observed that the continuous infusion of propofol in dogs, at the given doses, did not alter the basic variables of renal function and hemodynamics studied. We concluded that propofol can be one of the drugs of choice to provide base anesthesia in studies of renal function in dogs.

Tempo de latencia e duracao do efeito do brometo de rocuronio no paciente submetido ao transplante renal

Background and Objectives - Successful cadaver kidney transplantation relies on a fast procedure. Patients with chronic renal failure may present with a delayed gastric emptying making it critical a fast tracheal intubation and airway maintenance. Rocuronium a recently introduced nondepolarizing neuromuscular blocker with a fast onset. The aim of this study was to evaluate onset time and duration of rocuronium effects in patients undergoing renal transplantation. Methods - Sixty patients were allocated into two groups of 30: Group R (GR) = patients undergoing renal transplantation and Group N (GN) = patients with normal renal function. All patients were premedicated with oral midazolam (15 mg) and anesthesia was induced with 30 μg.kg-1 alfentanil, 0.3 mg.kg-1 etomidate and 0.6 mg.kg-1 rocuronium injected through a central venous catheter. neuromuscular block was monitored by acceleromyography in the ulnar nerve pathway. The following parameters were evaluated: time between administration of rocuronium and first twitch reduction to 5% after supra-maximal stimulation (T1) (onset time = OT); time for first twitch to return to 25% (clinical duration = R25); time elapsed between 25% and 75% recovery of first twitch (relaxation recovery time = R25-75). Heart rate (HR) and mean blood pressure (MBP) were recorded in 6 moments. Results - Median OT was 31 sec. in GR and 47 sec. in GN. Median R25 was 51.5 min in GR and 33.5 min in GN. Median R25-75 was 28 min in GR and 20 min in GN. MBP and HR were higher in GR. Tracheal intubation conditions were excellent for most patients in both groups. Conclusions - These results open the possibility of 0.6 mg.kg-1 rocuronium being injected through a central venous catheter when a faster onset is needed. Due to wide differences in individual responses, monitoring of neuromuscular block is recommended.

Outbreak of fungemia caused by Candida parapsilosis in a neonatal intensive care unit: Molecular investigation through microsatellite analysis

Background: Opportunistic infections are an increasingly common problem in hospitals, and the yeast Candida parapsilosis has emerged as an important nosocomial pathogen, especially in neonatal intensive care units (NICUs) where it has been responsible for outbreak cases. Risk factors for C. parapsilosis infection in neonates include prematurity, very low birth weight, prolonged hospitalization, indwelling central venous catheters, hyperalimentation, intravenous fatty emulsions and broad spectrum antibiotic therapy. Molecular methods are widely used to elucidate these hospital outbreaks, establishing genetic variations among strains of yeast. Aims: The aim of this study was to detect an outbreak of C. parapsilosis in an NICU at the Hospital das Clinicas , Faculty of Medicine of Botucatu, a tertiary hospital located in São Paulo, Brazil, using the molecular genotyping by the microsatellite markers analysis. Methods: A total of 11 cases of fungemia caused by C. parapsilosis were identified during a period of 43 days in the NICU. To confirm the outbreak all strains were molecularly typed using the technique of microsatellites. Results: Out of the 11 yeast samples studied, nine showed the same genotypic profile using the technique of microsatellites. Conclusions: Our study shows that the technique of microsatellites can be useful for these purposes. In conclusion, we detected the presence of an outbreak of C. parapsilosis in the NICU of the hospital analyzed, emphasizing the importance of using molecular tools, for the early detection of hospital outbreaks, and for the introduction of effective preventive measures, especially in NICUs. © 2012 Revista Iberoamericana de Micología.

Perioperative evaluation of tumescent anaesthesia technique in bitches submitted to unilateral mastectomy

Background: Tumescent anaesthesia (TA) is a widely used technique in oncologic surgeries necessitating large resection margins. This technique produces transoperative and postoperative analgesia, reduces surgical bleeding, and facilitates tissue divulsion. This prospective, randomised, blind study evaluated the use of TA in bitches submitted to mastectomy and compared the effect of TA with an intravenous fentanyl bolus. A 2.5-mcg/kg intravenous fentanyl bolus (n = 10) was compared with TA using 0.275% lidocaine (n = 10) in bitches submitted to unilateral mastectomy. Sedation was performed by intramuscular (IM) injection of 0.05 mg/kg of acepromazine combined with 2 mg/kg of meperidine. Anaesthesia was induced with 5 mg/kg of intravenous propofol and maintained with isoflurane/O2. Heart and respiratory rates; systolic, mean, and diastolic arterial blood pressures; central venous pressure; SpO2; ETCO2; inspired and expired isoflurane concentrations; and temperature were measured transoperatively. Visual analogue scales for sedation and pain and the Glasgow composite and Melbourne pain scales were used for postoperative assessment. The surgeon investigated the quality of the surgical approach, considering bleeding and resection ability, and the incidence of postoperative wound complications.Results: The heart rate was lower and the end-tidal isoflurane concentration was higher in dogs treated with fentanyl than in dogs treated with TA. A fentanyl bolus was administered to 8 of 10 dogs treated with fentanyl and to none treated with TA. Intraoperative bleeding and the mammary gland excision time were lower in dogs treated with TA. The maximal mean and individual plasma lidocaine concentrations were 1426 ± 502 ng/ml and 2443 ng/ml at 90 minutes after infiltration, respectively. The Glasgow Composite Pain Scale scores were higher in dogs treated with fentanyl than in dogs treated with TA until 2 hours after extubation.Conclusions: Compared with intravenous fentanyl, TA in bitches: may be easily performed in non-inflamed, ulcerated, adhered mammary tumours; has an isoflurane-sparing effect; improves transoperative and immediate postoperative analgesia; is apparently safe for use in clinical conditions as evidenced by the fact that it did not produce any adverse signs or lidocaine plasma concentrations compatible with toxicity; does not modify the recovery time; and facilitates the surgical procedure without interfering with wound healing. © 2013 Credie et al.; licensee BioMed Central Ltd.

Comportamento hemodinâmico e metabólico do choque hemorrágico: estudo experimental no cão

Pós-graduação em Anestesiologia - FMB