Sandra Mastrocinque

The use of different doses of metamizol for post-operative analgesia in dogs.

OBJECTIVE To evaluate the post-operative analgesic effect of metamizol (dipyrone) administered intravenously at three different doses (15 mg kg(-1), 25 mg kg(-1) and 35 mg kg(-1)) compared to placebo in dogs undergoing ovariohysterectomy. STUDY DESIGN Prospective, comparative, randomized, blinded trial. ANIMALS Forty healthy bitches, aged 1-6 years, weighing 10-35 kg METHODS The animals were randomly divided into four groups and received their respective treatments immediately after surgery: placebo group (0.9% saline solution), D15 group (metamizol 15 mg kg(-1) IV), D25 group (metamizol 25 mg kg(-1) IV), D35 group (metamizol 35 mg kg(-1) IV). The following variables were measured: sedation, pulse rate (PR), respiratory rate (f(R)), arterial blood pressure (ABP), plasma catecholamines, serum cortisol, blood urea nitrogen (BUN) and creatinine metabolites, albumin, alanine aminotransferase (ALT), alkaline phosphatase (ALP), hemogram, platelet counts and level of analgesia which was assessed by visual analog (VAS), descriptive and behavioral scales. Patients were monitored for 48 hours after the administration of the analgesic agent. Rescue analgesia (tramadol, 2 mg kg(-1), intramuscularly) was provided for animals with pain scores ≥4, as determined by the VAS or descriptive scale. RESULTS The D25 and D35 groups showed equivalent post-operative analgesia, as shown by decreased pain scores, according to the three different pain scales, and fewer animals that required rescue analgesia. Significantly lower serum cortisol concentrations were observed in the D25 and D35 groups when compared to the placebo and D15 groups. No hematologic, renal, hepatic or clinical adverse effects were observed during the treatment. CONCLUSIONS AND CLINICAL RELEVANCE Metamizol administered intravenously at 25 or 35 mg kg(-1) can provide adequate post-operative analgesia in bitches undergoing ovariohysterectomy.

Comparison of epidural and systemic tramadol for analgesia following ovariohysterectomy.

The objective of the study was to compare epidural and systemic tramadol for postoperative analgesia in bitches undergoing ovariohysterectomy. Twenty animals, randomly divided into two groups, received either epidural (EPI) or intramuscular (IM) tramadol (2 mg/kg) 30 min before anesthetic induction. Analgesia, sedation, cardiorespiratory parameters, end-tidal isoflurane, blood catecholamines and cortisol, and arterial blood gases were measured at different time points up to 24 hr after agent administration. There were no differences between the two groups regarding cardiorespiratory parameters, end-tidal isoflurane, and pain scores. Two dogs in the IM and one in the EPI group required supplemental analgesia. Cortisol was increased (P<0.05) at 120 min (3.59 μg/dL and 3.27 μg/dL in the IM and EPI groups, respectively) and 240 min (2.45 μg/dL and 2.54 μg/dL in the IM and EPI groups, respectively) compared to baseline. Norepinephrine was also increased (P<0.05) at 120 min in both groups compared to baseline values. Epinephrine values were higher (P<0.05) in the IM group compared with the EPI group at 50 min, 120 min, and 1,440 min after tramadol administration. Epidural tramadol is a safe analgesic, but does not appear to have improved analgesic effects compared with IM administration.

Emprego da ventilação mecânica com pressão controlada em circuito circular de anestesia para pacientes de baixo peso: estudo experimental

JUSTIFICATIVA Y OBJETIVOS: La anestesia con bajo flujo, en pacientes pediatricos, requiere equipamientos adecuados siendo caros los disponibles, y limitando su uso. Este estudio evaluo la anestesia con bajo flujo en conejos, empleando circuito cerrado, modo de presion controlada en nuevo ventilador pediatrico para anestesia (VPL-5000A-Vent-Logos). METODO: Diez conejos fueron distribuidos aleatoriamente, siendo que el grupo I fue sometido a presion de 15 cmH2O y el grupo II a la de 20 cmH2O. La anestesia fue realizada con xilazina (10 mg.kg-1) y cetamina (25 mg.kg-1) asociados, por via muscular, seguida de manutencion con isoflurano, despues intubacion orotraqueal. Despues de 20 minutos, se administro pancuronio (0,1 mg.kg-1) por via venosa y la ventilacion controlada fue iniciada. Los parametros ajustados y el ventilador fueron: FR 30 mpm, frecuencia I:E 1:2,5 y tiempo de inspiracion 0,6 segundo, ademas de las presiones de plateau. El flujo de gases frescos empleado fue de 300 ml (total). Los parametros fueron colectados a cada 20 minutos durante una hora. Los datos obtenidos fueron sometidos a analisis estadistica de variancia para medidas repetidas (p < 0,05). RESULTADOS: El CO2 reinhalado diminuyo significativamente en el grupo II, de 15 mmHg, durante la ventilacion espontanea, para un valor medio de 2,4 mmHg durante a ventilacion controlada. En el grupo I, de 19,2 mmHg (inicial) para 3,6 mmHg. Comparandose los dos grupos, diferencias significativas fueron encontradas en relacion al pH venoso, PaCO2, PvO2 y discreta diferencia entre la PAM y PAD. El grupo de 15 cmH2O presento importante acidosis respiratoria, en cuanto el de 20 cmH2O obtuvo valores normales de pH y PaCO2. Una vez que los valores de volumen expirado entre los grupos fueron semejantes, tales diferencias entre pH y gases sanguineos presentados por los grupos pueden estar relacionadas a los bajos niveles de pH observados en el grupo I. Se Verifico consumo medio de 2 ml de isoflurano por animal durante los 120 minutos de estudio. CONCLUSIONES: Con equipamiento adecuado es posible emplear anestesia de bajo flujo, ventilacion con presion controlada y circuito cerrado en pacientes con muy bajo peso.BACKGROUND AND OBJECTIVES: Pediatric low flow anesthesia requires adequate equipment which, when available, is extremely expensive, thus seldom used. This study aimed at evaluating low flow anesthesia in rabbits using a closed rebreathing circuit in a new pediatric pressure controlled ventilator for anesthesia. METHODS: Ten rabbits were randomly assigned to two groups. Group I individuals were ventilated with the airway pressure limit set to 15 cmH2O, while in group II the setting was 20 cm H2O. Anesthesia was induced with muscular xylazine (10 mg.kg-1) and ketamine (25 mg.kg-1), followed by maintenance with isoflurane after tracheal intubation. After 20 minutes, 0.1 mg.kg-1 intravenous pancuronium was administered and controlled ventilation was established. Ventilator parameters were: RR - 30 mpm, I:E ratio 1:2.5 and inspiratory time 0.6 sec, in addition to plateau pressures. Fresh gas flow was 300 ml.min-1 (total). Parameters were collected every 20 minutes for one hour and data were submitted to analysis of variance for repeated measures (p < 0.05). RESULTS: Re-inhaled CO2 decreased significantly in group II from an initial value of 15 mmHg during spontaneous ventilation to a mean value of 2.4 mmHg during controlled ventilation. In group I, the drop was from 19.2 mmHg (initial) to 3.6 mmHg. Comparing both groups, significant differences were observed in venous pH, PaCO2, PvO2 and a slight difference between MBP and DBP. The 15 cmH2O group showed important respiratory acidosis, while the 20 cmH2O had normal pH and PaCO2 values. Since expired volume values were similar in both groups, such differences in pH and blood gases observed could be related to low pH levels seen in group I. Each animal consumed a mean value of 2 ml isoflurane during the 120 minutes of the study. CONCLUSIONS: With proper equipment, it is possible to use low flow anesthesia with pressure controlled ventilation and closed system in very low weight patients.

Empleo de la ventilación mecánica con presión controlada en circuito circular de anestesia para pacientes de bajo peso: estudio experimental

JUSTIFICATIVA Y OBJETIVOS: La anestesia con bajo flujo, en pacientes pediatricos, requiere equipamientos adecuados siendo caros los disponibles, y limitando su uso. Este estudio evaluo la anestesia con bajo flujo en conejos, empleando circuito cerrado, modo de presion controlada en nuevo ventilador pediatrico para anestesia (VPL-5000A-Vent-Logos). METODO: Diez conejos fueron distribuidos aleatoriamente, siendo que el grupo I fue sometido a presion de 15 cmH2O y el grupo II a la de 20 cmH2O. La anestesia fue realizada con xilazina (10 mg.kg-1) y cetamina (25 mg.kg-1) asociados, por via muscular, seguida de manutencion con isoflurano, despues intubacion orotraqueal. Despues de 20 minutos, se administro pancuronio (0,1 mg.kg-1) por via venosa y la ventilacion controlada fue iniciada. Los parametros ajustados y el ventilador fueron: FR 30 mpm, frecuencia I:E 1:2,5 y tiempo de inspiracion 0,6 segundo, ademas de las presiones de plateau. El flujo de gases frescos empleado fue de 300 ml (total). Los parametros fueron colectados a cada 20 minutos durante una hora. Los datos obtenidos fueron sometidos a analisis estadistica de variancia para medidas repetidas (p < 0,05). RESULTADOS: El CO2 reinhalado diminuyo significativamente en el grupo II, de 15 mmHg, durante la ventilacion espontanea, para un valor medio de 2,4 mmHg durante a ventilacion controlada. En el grupo I, de 19,2 mmHg (inicial) para 3,6 mmHg. Comparandose los dos grupos, diferencias significativas fueron encontradas en relacion al pH venoso, PaCO2, PvO2 y discreta diferencia entre la PAM y PAD. El grupo de 15 cmH2O presento importante acidosis respiratoria, en cuanto el de 20 cmH2O obtuvo valores normales de pH y PaCO2. Una vez que los valores de volumen expirado entre los grupos fueron semejantes, tales diferencias entre pH y gases sanguineos presentados por los grupos pueden estar relacionadas a los bajos niveles de pH observados en el grupo I. Se Verifico consumo medio de 2 ml de isoflurano por animal durante los 120 minutos de estudio. CONCLUSIONES: Con equipamiento adecuado es posible emplear anestesia de bajo flujo, ventilacion con presion controlada y circuito cerrado en pacientes con muy bajo peso.BACKGROUND AND OBJECTIVES: Pediatric low flow anesthesia requires adequate equipment which, when available, is extremely expensive, thus seldom used. This study aimed at evaluating low flow anesthesia in rabbits using a closed rebreathing circuit in a new pediatric pressure controlled ventilator for anesthesia. METHODS: Ten rabbits were randomly assigned to two groups. Group I individuals were ventilated with the airway pressure limit set to 15 cmH2O, while in group II the setting was 20 cm H2O. Anesthesia was induced with muscular xylazine (10 mg.kg-1) and ketamine (25 mg.kg-1), followed by maintenance with isoflurane after tracheal intubation. After 20 minutes, 0.1 mg.kg-1 intravenous pancuronium was administered and controlled ventilation was established. Ventilator parameters were: RR - 30 mpm, I:E ratio 1:2.5 and inspiratory time 0.6 sec, in addition to plateau pressures. Fresh gas flow was 300 ml.min-1 (total). Parameters were collected every 20 minutes for one hour and data were submitted to analysis of variance for repeated measures (p < 0.05). RESULTS: Re-inhaled CO2 decreased significantly in group II from an initial value of 15 mmHg during spontaneous ventilation to a mean value of 2.4 mmHg during controlled ventilation. In group I, the drop was from 19.2 mmHg (initial) to 3.6 mmHg. Comparing both groups, significant differences were observed in venous pH, PaCO2, PvO2 and a slight difference between MBP and DBP. The 15 cmH2O group showed important respiratory acidosis, while the 20 cmH2O had normal pH and PaCO2 values. Since expired volume values were similar in both groups, such differences in pH and blood gases observed could be related to low pH levels seen in group I. Each animal consumed a mean value of 2 ml isoflurane during the 120 minutes of the study. CONCLUSIONS: With proper equipment, it is possible to use low flow anesthesia with pressure controlled ventilation and closed system in very low weight patients.

Controlled pressure mechanical ventilation with anesthesia closed system for low weight patients: experimental study

JUSTIFICATIVA Y OBJETIVOS: La anestesia con bajo flujo, en pacientes pediatricos, requiere equipamientos adecuados siendo caros los disponibles, y limitando su uso. Este estudio evaluo la anestesia con bajo flujo en conejos, empleando circuito cerrado, modo de presion controlada en nuevo ventilador pediatrico para anestesia (VPL-5000A-Vent-Logos). METODO: Diez conejos fueron distribuidos aleatoriamente, siendo que el grupo I fue sometido a presion de 15 cmH2O y el grupo II a la de 20 cmH2O. La anestesia fue realizada con xilazina (10 mg.kg-1) y cetamina (25 mg.kg-1) asociados, por via muscular, seguida de manutencion con isoflurano, despues intubacion orotraqueal. Despues de 20 minutos, se administro pancuronio (0,1 mg.kg-1) por via venosa y la ventilacion controlada fue iniciada. Los parametros ajustados y el ventilador fueron: FR 30 mpm, frecuencia I:E 1:2,5 y tiempo de inspiracion 0,6 segundo, ademas de las presiones de plateau. El flujo de gases frescos empleado fue de 300 ml (total). Los parametros fueron colectados a cada 20 minutos durante una hora. Los datos obtenidos fueron sometidos a analisis estadistica de variancia para medidas repetidas (p < 0,05). RESULTADOS: El CO2 reinhalado diminuyo significativamente en el grupo II, de 15 mmHg, durante la ventilacion espontanea, para un valor medio de 2,4 mmHg durante a ventilacion controlada. En el grupo I, de 19,2 mmHg (inicial) para 3,6 mmHg. Comparandose los dos grupos, diferencias significativas fueron encontradas en relacion al pH venoso, PaCO2, PvO2 y discreta diferencia entre la PAM y PAD. El grupo de 15 cmH2O presento importante acidosis respiratoria, en cuanto el de 20 cmH2O obtuvo valores normales de pH y PaCO2. Una vez que los valores de volumen expirado entre los grupos fueron semejantes, tales diferencias entre pH y gases sanguineos presentados por los grupos pueden estar relacionadas a los bajos niveles de pH observados en el grupo I. Se Verifico consumo medio de 2 ml de isoflurano por animal durante los 120 minutos de estudio. CONCLUSIONES: Con equipamiento adecuado es posible emplear anestesia de bajo flujo, ventilacion con presion controlada y circuito cerrado en pacientes con muy bajo peso.BACKGROUND AND OBJECTIVES: Pediatric low flow anesthesia requires adequate equipment which, when available, is extremely expensive, thus seldom used. This study aimed at evaluating low flow anesthesia in rabbits using a closed rebreathing circuit in a new pediatric pressure controlled ventilator for anesthesia. METHODS: Ten rabbits were randomly assigned to two groups. Group I individuals were ventilated with the airway pressure limit set to 15 cmH2O, while in group II the setting was 20 cm H2O. Anesthesia was induced with muscular xylazine (10 mg.kg-1) and ketamine (25 mg.kg-1), followed by maintenance with isoflurane after tracheal intubation. After 20 minutes, 0.1 mg.kg-1 intravenous pancuronium was administered and controlled ventilation was established. Ventilator parameters were: RR - 30 mpm, I:E ratio 1:2.5 and inspiratory time 0.6 sec, in addition to plateau pressures. Fresh gas flow was 300 ml.min-1 (total). Parameters were collected every 20 minutes for one hour and data were submitted to analysis of variance for repeated measures (p < 0.05). RESULTS: Re-inhaled CO2 decreased significantly in group II from an initial value of 15 mmHg during spontaneous ventilation to a mean value of 2.4 mmHg during controlled ventilation. In group I, the drop was from 19.2 mmHg (initial) to 3.6 mmHg. Comparing both groups, significant differences were observed in venous pH, PaCO2, PvO2 and a slight difference between MBP and DBP. The 15 cmH2O group showed important respiratory acidosis, while the 20 cmH2O had normal pH and PaCO2 values. Since expired volume values were similar in both groups, such differences in pH and blood gases observed could be related to low pH levels seen in group I. Each animal consumed a mean value of 2 ml isoflurane during the 120 minutes of the study. CONCLUSIONS: With proper equipment, it is possible to use low flow anesthesia with pressure controlled ventilation and closed system in very low weight patients.