SUFENTANIL INTRANASAL COME MEDICACAO PRE-ANESTESICA EM CRIANCAS

Background and objectives: Among the different routes used for the administration of preoperative medication, the intranasal route offers the advantage of a rapid systemic absorption as well as the avoidance of painful intramuscular and intravenous injections. The aim of the present study is to evaluate the efficacy of sufentanil as a preoperative medication for the reduction of anxiety in pediatric patients in addition to its effects on the children's behaviour during the induction of anesthesia. Methods - Thirty patients whose ages ranged from 1 to 9 years old, physical status ASA 1, submitted to elective surgeries participated in the study and received sufentanil (2 μg.kg-1) by the intranasal route as preoperative medication. Using the modified Doughty index, the anxiety level was evaluated at 3 moments: To upon arrival of the child with parents: T5 and T10, five and ten minutes after the administration of the drug respectively. Behaviour during the induction of anesthesia was also evaluated. Induction of anesthesia was performed thiopental or ketamine. Results - The level of anxiety was not lower ten minutes after the administration of sufentanil and no improvement in the quality of the anesthetic induction was observed. Conclusions - Intranasal sufentanil in the doses used in this study did not prove to be efficient in the reduction of the anxiety level nor did it improve the quality of the induction of anesthesia when the period between the drug administration and separation from the parents was only ten minutes.

Cardiorespiratory, endocrine and metabolic changes in ponies undergoing intravenous or inhalation anaesthesia

Six Welsh gelding ponies (weight 246 ± 6 kg) were premedicated with 0.03 mg/kg of acepromazine intravenously (i.v.) followed by 0.02 mg/kg of detomidine i.v. Anaesthesia was induced with 2 mg/kg of ketamine i.v. Ponies were intubated and lay in left lateral recumbency. On one occasion anaesthesia was maintained for 2 h using 1.2% halothane in oxygen. The same group of ponies were anaesthetized 1 month later using the same induction regime and anaesthesia was maintained with a combination of detomidine, ketamine and guaiphenesin, while the ponies breathed oxygen-enriched air. Electrocardiogram, heart rate, mean arterial blood pressure, cardiac output, respiratory rate, blood gases, temperature, haematocrit, glucose, lactate and cortisol were measured and cardiac index and systemic vascular resistance were calculated in both groups. Beta-endorphin, met-enkephalin, dynorphin, arginine vasopressin (AVP), adrenocorticotrophic hormone (ACTH) and catecholamines were measured in the halothane anaesthesia group only and 11-deoxycortisol during total intravenous anaesthesia (TIVA) only. Cardiorespiratory depression was more marked during halothane anaesthesia. Hyperglycaemia developed in both groups. Lactate and AVP increased during halothane anaesthesia. Cortisol increased during halothane and decreased during TIVA. There were no changes in the other hormones during anaesthesia. Recovery was smooth in both groups. TIVA produced better cardiorespiratory performance and suppressed the endocrine stress response observed during halothane anaesthesia.

Endocrine changes in cerebrospinal fluid, pituitary effluent, and peripheral plasma of anesthetized ponies

Objective - To investigate the effects of inhalation and total IV anesthesia on pituitary-adrenal activity in ponies. Animals - 9 healthy ponies: 5 geldings and 4 mares. Procedure - Catheters were placed in the cavernous sinus below the pituitary gland and in the subarachnoid space via the lumbosacral space. After 72 hours, administration of acepromazine was followed by induction of anesthesia with thiopentone and maintenance with halothane (halothane protocol), or for the IV protocol, anesthesia induction with detomidine and ketamine was followed by maintenance with IV infusion of a detomidine-ketamine-guaifenesin combination. Arterial blood pressure and gas tensions were measured throughout anesthesia. Peptide and catecholamine concentrations were measured in pituitary effluent, peripheral plasma, and CSF. Peripheral plasma cortisol, glucose, and lactate concentrations also were measured. Results - Intravenous anesthesia caused less cardiorespiratory depression than did halothane. ACTH, metenkephalin, arginine vasopressin, and norepinephrine pituitary effluent and peripheral plasma concentrations were higher during halothane anesthesia, with little change during intravenous anesthesia. Pituitary effluent plasma β-endorphin and peripheral plasma cortisol concentrations increased during halothane anesthesia only. Dynorphin concentrations did not change in either group. Hyperglycemia developed during intravenous anesthesia only Minimal changes occurred in CSF hormonal concentrations during anesthesia. Conclusion - The pituitary gland has a major role in maintaining circulating peptides during anesthesia. Compared with halothane, IV anesthesia appeared to suppress pituitary secretion.

Avaliação experimental dos efeitos do anestésico local ropivacaína em nervos ciáticos

This study was undertaken to investigate the effects of ropivacaine after intrafascicular injection into the sciatic nerves of albino rabbits. Twenty adult albine rabbits were used, following sedation with intramuscular ketamine (50 mg/kg) for nerve exposure by lateral incision. We considered three experimental groups: Group I:sciatic nerve control; Group II: intrafascicular injection with 0.2 mL of physiologic saline solution in the left nerves and intrafascicular injection with 0.2 mL of local anesthetic ropivacaine into the rigth nerves. The specimens were colected at 48 h after drugs administration; Group III. intrafascicular injection with 0.2 mL of physiologic saline solution in the left nerves and intrafascicular injection with 0.2 mL of local anesthetic ropivacaine in the rigth nerves. The specimens were colected at 7 days after drugs administration. The sciatic nerves were removed from these animals and fixed in Karnowisky solution for 24 hours. After partial dehydration up to 95% ethanol, they were embedded in historesin (Leica). The tissue was then sectioned at 1-2μm. Sections were stained with haematoxylin-eosin (HE); toluidine blue (TB) or picrosirius-haematoxylin (PSH). Comparing with control group the histological evidence of inflammatory reaction (migration of macrophagic cells and eosinophils-appeared soon after injection, with intense proliferation of perineurial cells. The results show that after 7 days of intrafascicular injection there was a severe fibrosis and an increase on perineurial vascularization. In group 2 the inflammatory reaction was noted near the local of the injection. Furthermore in this experiment we observed an increase on the number of epineurial lipoblasts and adipocytes. This study demonstrated that the toxic effects of ropivacaine are transient. In many cases there was an initial fascicular recover and axonal regeneration after 7 days of the injection.

Histomorphometric analysis of homogenous demineralized dentin matrix as osteopromotive material in rabbit mandibles

Purpose: The aim of this work was to evaluate the effectiveness of homogenous demineralized dentin matrix (HDDM) slices in surgical bone defects created in the mandibles of rabbits and occluded with a polytetrafluoroethylene (PTFE) membrane in the promotion of bone growth. Materials and Methods: Surgical bone defects were created in 36 adult rabbits and divided into 4 groups: bone defect (control), bone defect with PTFE membrane, bone defect with HDDM, and bone defect with both HDDM and a PTFE membrane (HDDM + PTFE). The rabbits were sacrificed after 30, 60, and 90 days, and the bone defects were examined histologically and by histomorphometric analysis (analysis of variance and the Tukey test). Results: The volume of newly formed bone matrix was significantly greater in the HDDM and HDDM + PTFE groups than in the control and PTFE groups. The discrete inflammatory reaction found in the HDDM and HDDM + PTFE groups did not prevent the osteopromotive activity of the dentin matrix. Discussion: HDDM slices were biocompatible and were resorbed during the bone remodeling process. They stimulated the newly formed bone until 30 days after implantation. Conclusion: Bone repair was accelerated in the bone defects treated with HDDM in comparison to the control group.

Comparison of hemodynamic, clinicopathologic, and gastrointestinal motility effects and recovery characteristics of anesthesia with isoflurane and halothane in horses undergoing arthroscopic surgery

Objective - To compare hemodynamic, clinicopathologic, and gastrointestinal motility effects and recovery characteristics of halothane and isoflurane in horses undergoing arthroscopic surgery. Animals - 8 healthy adult horses. Procedure - Anesthesia was maintained with isoflurane or halothane (crossover study). At 6 intervals during anesthesia and surgery, cardiopulmonary variables and related derived values were recorded. Recovery from anesthesia was assessed; gastrointestinal tract motility was subjectively monitored for 72 hours after anesthesia. Horses were administered chromium, and fecal chromium concentration was used to assess intestinal transit time. Venous blood samples were collected for clinicopathologic analyses before and 2, 24, and 48 hours after anesthesia. Results - Compared with halothane-anesthetized horses, cardiac index, oxygen delivery, and heart rate were higher and systemic vascular resistance was lower in isoflurane-anesthetized horses. Mean arterial blood pressure and the dobutamine dose required to maintain blood pressure were similar for both treatments. Duration and quality of recovery from anesthesia did not differ between treatments, although the recovery periods were somewhat shorter with isoflurane. After isoflurane anesthesia, gastrointestinal motility normalized earlier and intestinal transit time of chromium was shorter than that detected after halothane anesthesia. Compared with isoflurane, halothane was associated with increases in serum aspartate transaminase and glutamate dehydrogenase activities, but there were no other important differences in clinicopathologic variables between treatments. Conclusions and clinical relevance - Compared with halothane, isoflurane appears to be associated with better hemodynamic stability during anesthesia, less hepatic and muscle damage, and more rapid return of normal intestinal motility after anesthesia in horses undergoing arthroscopic procedures.

Injeção epidural de cetamina ou cetamina levógira no controle da dor pós-incisional, em eqüinos

The aim of this study was to evaluate the pre-emptive effect of epidural ketamine S (+) (SK) or racemic ketamine (RK) administration, in post-incisional pain in horses. Were used in a blinded, randomized experimental study, sixteen mixed breed mares, 6±2 years old, weighting 273.2±42.0 kg. An epidural catheter was inserted 24 hours before the trials. The thigh region was shaved bilaterally, and mechanical cutaneous sensibility was measured using von Frey filaments (T-30). Using the left side as the control one, local anesthesia was performed at the right side. Twenty-five minutes later, SK was injected in G1 or RK in G2 through the epidural catheter. Five minutes after the ketamine injection, a 10 cm skin incision was made on the right side, and then sutured. Mechanical post-incisional pain was measured using von Frey filaments, at 1, 3 and 5 cm around the incision at 15 minutes intervals, for 2 hours, then 4, 6 and 8 hours after suturing. No changes were observed in the heart and respiratory rate and rectal temperature among groups or times of each group. Hind limb ataxia was observed in 62.5% and 12.5% of G1 and G2 respectively. SK and RK reduced cutaneous sensibility in the right and the left sides to mechanical postincisional pain during all time of experiment. Epidural SK and RK produce similar post-incisional analgesic effects, did not interfere in the cardio-respiratory parameters. The SK induces more intense ataxia in mares and presents a larger analgesic potency in the first 60 minutes after the administration.

Efeito da lavagem peritoneal com bupivacaína na sobrevida de ratos com peritonite fecal

BACKGROUND AND OBJECTIVES: Based on the knowledge of the anti-inflammatory and anti-bacterial actions of local anesthetics (LA), the objective of this study was to determine the effects of peritoneal lavage with bupivacaine on survival of mice with fecal peritonitis. METHODS: Forty-eight Wistar mice, weighing between 300 and 330 g (311.45 ± 9.67 g), undergoing laparotomy 6 hours after induction of peritonitis were randomly divided in 4 groups: 1 - Control, without treatment (n = 12); 2 - Drying of the abdominal cavity (n = 12); 3 - Lavage with 3 mL NS and posterior drying of the abdominal cavity (n = 12); and 4 - Lavage with 8 mg.kg -1 (± 0.5 mL) of 0.5% bupivacaine added to 2.5 mL of NS followed by drying out of the abdominal cavity (n = 12). Animals that died underwent necropsy and the time of death was recorded. Surviving animals were killed on the 11 th postoperative day and underwent necropsy. RESULTS: Group 1 presented a 100% mortality rate in 52 hours, 100% mortality rate in Group 2 in 126 hours, and Group 3 presented a 50% mortality rate in 50 hours. Animals in Group 4 survived. Survival on the 11 th day was greater in groups 3 and 4 than in Groups 1 and 2 (p < 0.001) and greater in Group 4 than in Group 3 (p < 0.01). CONCLUSIONS: Peritoneal lavage with a solution of bupivacaine diluted in NS was effective in preventing death for 11 days in 100% of animals with fecal peritonitis. © Sociedade Brasileira de Anestesiologia, 2008.

Determinação de cetamina em plasma por HPLC: Aplicação em um estudo de farmacocinética de associação medicamentosa em cães

A S(+) cetamina é um fármaco amplamente utilizado na medicina para induzir anestesia e a associação com midazolam é empregada para minimizar seus efeitos adversos. Associações medicamentosas podem resultar em interações farmacocinéticas e a disponibilidade de métodos bioanalíticos para a determinação da cetamina em plasma constitui ferramenta útil para a avaliação do perfil cinético do fármaco administrado isoladamente ou em associação. O presente estudo teve como objetivo o desenvolvimento e validação de um método analítico para determinação da cetamina em plasma por cromatografia líquida de alta eficiência (HPLC) e a investigação do perfil farmacocinético da cetamina em quatro cães hígidos da raça Beagle. A S(+) cetamina (10mg/kg) foi administrada pela veia cefálica em dose única isoladamente (protocolo I) ou associada ao midazolam (0.2mg/kg) (protocolo II) em estudo cruzado com intervalo de uma semana para washout. Amostras seriadas de sangue foram coletadas no intervalo de oito horas e analisadas por HPLC para a avaliação do perfil farmacocinético utilizando modelo bicompartimental. O método bioanalítico apresentou limites de confiança aceitáveis para sua aplicação em estudos de farmacocinética e os parâmetros área sob a curva (ASC0-8), volume de distribuição (Vd), clearance total (Clt), meia vida de eliminação (t/12 ß), constante de eliminação (ß), meia vida de distribuição (t1/2α) e constante de distribuição (α) não mostraram diferenças estatísticas significativas entre os grupos (p < 0.05, Wilcoxon). Os resultados obtidos sugerem que a redução dos efeitos colaterais da cetamina decorrente do uso da associação cetamina-midazolam não está relacionada a alterações no perfil farmacocinético da cetamina.

Analgésicos Tópicos

Background and objectives: Pain treatment involves the usage of common and opioid analgesics, nonsteroidal anti-inflammatory drugs (NSAIDs) and adjuvant analgesics. Traditionally, these drugs are administered systemically or into the neuraxis. However, when analgesics are applied through these pathways, they are associated with significant side effects, which can hinder its use. Topical administration of analgesics is an alternative. The objective of this paper is to discuss topical analgesics, the mechanisms of action and clinical efficacy. Content: This is a review paper addressing the usage of the topical local anesthetics: capsaicin, clonidine, tricyclic antidepressants, ketamine, opioids and cannabinoids, discussing mechanism of action and effectiveness. Conclusions: Topical analgesics are promising as a strategy for pain treatment, as they are associated with lower incidence of side effects. The benefit of local anesthetics, NSAID's and capsaicin is well established. However, the efficacy of clonidine, tricyclic antidepressants, ketamine, opioids and cannabinoids is still questionable. Studies have shown that the multimodal approach is an alternative, but studies are needed to confirm this hypothesis. © 2012 Elsevier Editora Ltda.

Sobre a analgesia pós-operatória da morfina, cetamina ou da associação em cadelas submetidas à ovariossalpingohisterectomia eletiva

This study aimed to evaluate the post operative analgesic effects of morphine or ketamine alone or their combination in 24 healthy bitches, weighing 11.01±8.69kg and aging 27±17 months, submitted to elective ovariohysterectomy. The animals were distributed to one of the three treatments after the anaesthetic induction: morphine (GM, n=8, 0.5mg kg-1 IM), ketamine (GK, n=8, 2.5mg kg-1 IM) or ketamine combined to morphine (GKM) using the same doses previously described. Sedation score and pain assessment were performed blindly two hours before surgery and at 1, 2, 4, 8, 12, and 24 hours after extubation, using the Dobbins scale (sedation) and visual analogue scale (pain) and Glasgow modified pain scale (GMPS). Rescue analgesia was performed with 1.0mg kg-1 of morphine and if not sufficient, followed by 0.2mg kg-1 of meloxicam, both IM, when the GMPS reached above 33% of the total score. Non parametric data were analyzed using Friedmańs test followed by Dunńs test for differences in time. Kruskal-Walliś test followed by Dunńs test were used to investigate differences in the number of analgesic rescues and among groups at each time. Parametric data were evaluated by ANOVA followed by Tukey's test (P<0.05). Except for GMPS, where the values of GM were greater than for GKM at 1h post-extubation, there were no other differences among groups. The number of rescue analgesia was greater in GM (11 in total; twice in 3 animals,) when compared to GKM (3; twice in 1 animal) and GK (2; twice in 1 animal). Analgesia provided by pre-incisional ketamine was more effective when compared to morphine. According to that, ketamine alone may be used as a preemptive analgesic in bitches undergoing ovariohysterectomy; however, rescue analgesia may be necessary.

Effects of constant rate infusion of anesthetic or analgesic drugs on general anesthesia with isoflurane: A retrospective study in 200 dogs

Constant rate infusion (CRI) shows several advantages in balanced anesthesia, such as reduction of requirement for inhaled anesthetics and control of pain. The most commonly used drugs in these protocols are local anesthetics, dissociative, and opioids, which may be administered alone or in combinations. We evaluated the records of 200 dogs that underwent various surgical procedures with anesthetic or analgesic CRI in the perioperative period during 2011 and 2012 at the Veterinary Hospital of Franca University (Unifran), and identified possible complications during the transoperative period. Records evaluated included clinical state, laboratory tests, drugs used in premedication and induction, and CRI protocol. Acepromazine and morphine were the main drugs used in premedication. Propofol was used to induce anesthesia alone or in combination with other agents. We evaluated records of the 25 different CRI protocols. Fentanyl was the main drug employed in CRI, either alone or in combination. There were 128 episodes of anesthetic complications during CRI;the most common were hypotension, hypertension, and tachycardia, which occurred in 43 (32%), 35 (26.3%), and 19 (14.2%) dogs, respectively. Cardiac arrhythmia was reported in only 4 dogs. Signs of respiratory depression were present in dogs treated with 6 different CRI protocols. The consumption of isoflurane (vol %) reduced between 15.7% and 21.05% after 30minutes of the CRI in the fentanyl and fentanyl-lidocaine-ketamine CRI groups (p<0.05). In conclusion, CRI is a valid component of balanced anesthesia in dogs, safe, and has a low incidence of adverse effects. However, future studies are warranted to describe the results of the clinical use of CRI to better characterize and refine this technique.