Publications (72) View all
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Article: Pharmacokinetics of 0.5% levobupivacaine following ilioinguinal-iliohypogastric nerve blockade in children.
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ABSTRACT: Bupivacaine (2 mg kg(-1)) has been recommended for blockade of the ilioinguinal and iliohypogastric nerves in paediatric patients undergoing inguinal surgery. We determined the plasma concentrations of levobupivacaine following ilioinguinal-iliohypogastric block. Twenty children scheduled for elective surgery for inguinal surgery received 2 mg kg(-1) of 0.5% levobupivacaine. Surgical anaesthesia was maintained with mask inhalation of oxygen, nitrous oxide and sevoflurane. Venous blood samples were drawn at regular intervals up to 2 h and plasma was separated. Total venous plasma concentrations were determined by gas chromatography. Bupivacaine concentrations from a study with a similar protocol were used as historical controls for comparison. The groups were similar with respect to age, weight and dosage of local anaesthetic. The initial distribution half-time (Talpha), the peak plasma concentration (Cmax) achieved, the time to the peak plasma concentration were similar (Tmax), and the mean areas under the concentration time curve (AUC) were similar between the two local anaesthetics. Levobupivacaine and bupivacaine are equally absorbed to similar maximum concentrations.Acta Anaesthesiologica Scandinavica 04/2005; 49(3):397-400. · 2.19 Impact Factor -
Article: Pharmacokinetics of 0.75% ropivacaine and 0.5% bupivacaine after ilioinguinal-iliohypogastric nerve block in children.
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ABSTRACT: Blockade of the ilioinguinal and iliohypogastric nerves is a useful procedure in paediatric patients undergoing inguinal surgery. Bupivacaine 2 mg kg-1 has been recommended for this block. We compared the plasma concentrations of ropivacaine and bupivacaine following an ilioinguinal-iliohypogastric block. Forty children scheduled for elective inguinal surgery were randomized to receive 2 mg kg-1 of either 0.75% ropivacaine or 0.5% bupivacaine. Surgical anaesthesia was maintained with mask inhalation of oxygen, nitrous oxide and sevoflurane. Venous blood samples were drawn at regular intervals for up to 2 h and plasma was separated. Total venous plasma concentrations were determined by gas chromatography. The groups were similar with respect to age, weight and dose of local anaesthetic. The peak plasma concentration achieved was significantly higher in the bupivacaine group compared with the ropivacaine group (2.2 vs 1.2 micrograms ml-1, P = 0.025). The time to peak plasma concentration was significantly shorter in the bupivacaine group (24 vs 35 min, P = 0.024). The initial distribution half time of bupivacaine was significantly shorter (3.6 vs 6.5 min, P = 0.020) compared with that of ropivacaine. Bupivacaine is more rapidly absorbed from the injection site and leads to higher plasma concentrations than ropivacaine.BJA British Journal of Anaesthesia 10/2002; 89(3):438-41. · 4.24 Impact Factor -
Article: Apoptotic activity is increased in brain cortex infarct after hypothermic circulatory arrest in a porcine model.
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ABSTRACT: It has been shown that apoptosis contributes to neuronal cell death after ischemia, and we evaluated the degree of apoptotic activity occurring in brain cortex of pigs after hypothermic circulatory arrest (HCA). Thirty-one pigs underwent 75 min of HCA at 20 degrees C. Histological examination of the brain was performed, and slides of brain cortex were evaluated for apoptotic activity by the TUNEL method. Ten animals died during the first postoperative day and 21 survived until the seventh postoperative day. Brain cortex infarcts were found in animals that survived 7 days and these were included in this study. The median histopathological score among animals that died on the first postoperative day was 3.0 (range, 2-4), whereas it was 4.0 (range, 2-4) among survivors (p = 0.019). The apoptotic index was particularly high in the area of the infarct, whereas only a few TUNEL-stained cells were observed in noninfarcted areas. The apoptotic index was nil in all pigs that died in the first postoperative period, whereas it was 2.0 (range, 0-6) among the animals that survived until the seventh postoperative day (p < 0.0001). The apoptotic index was significantly increased in brain cortex infarcts of animals that survived 7 days after HCA, whereas only a few apoptotic cells were observed in noninfarcted areas of these animals as well as in animals that died on the first postoperative day. Further studies are required to elucidate the timing of development of brain infarction after HCA and whether neuroprotective strategies targeting the apoptotic process may mitigate brain damage.Scandinavian Cardiovascular Journal 08/2002; 36(4):247-9. · 0.93 Impact Factor -
Article: The role of cerebral microdialysis in predicting the outcome after experimental hypothermic circulatory arrest.
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ABSTRACT: To evaluate whether and which of the cerebral microdialysis parameters are predictive of postoperative outcome after an experimental 75-min period of hypothermic circulatory arrest (HCA) in a chronic porcine model. Seventy-four juvenile female pigs underwent a 75-min period of HCA at 20 degrees C. A microdialysis catheter was placed into the cortex gray matter and brain extracellular concentrations of glucose, lactate, glycerol and glutamate were measured throughout the experiment by enzymatic methods using a microdialysis analyzer. Surviving animals were sacrificed on the 7th postoperative day and histopathological examination of the brain was performed. Brain glucose concentrations were higher in animals that survived (p = 0.017), especially from the 90-min until the 7-h interval after the start of rewarming. The blood venous concentrations of glucose were also higher among survivors, and correlated significantly with the brain glucose levels at 2-h and 4-h intervals after the start of rewarming. Higher concentrations of brain lactate, glycerol and glutamate were observed throughout the study among animals that died postoperatively. Brain glutamate and glycerol concentrations were significantly, negatively correlated with brain glucose concentrations. The lactate/glucose ratio was significantly lower among survivors during the postoperative period (p=0.014). Furthermore, brain glucose concentrations were higher and brain glycerol concentrations lower among the animals that did not develop brain infarction, but such differences did not reach statistical significance. Cerebral microdialysis is a useful tool for cerebral monitoring during experimental HCA. Low brain glucose concentrations and high brain lactate/glucose ratios after HCA are strong predictors of postoperative death. Brain glucose concentrations are negatively correlated with brain glycerol and glutamate concentrations.Scandinavian Cardiovascular Journal 01/2002; 35(6):395-402. · 0.93 Impact Factor -
Article: Determinants of mortality after hypothermic circulatory arrest in a chronic porcine model.
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ABSTRACT: Beside neurological morbidity, mortality is a relevant end-point of experimental porcine model of hypothermic circulatory arrest (HCA) and this study was conducted to identify the determinants for postoperative death. One hundred and thirty-five pigs underwent a 75-min period of HCA at 20 degrees C to evaluate the efficacy of different methods of cerebral protection. Survival rate at 7-day follow-up was 52%. Lower oxygen extraction, oxygen consumption/kg, and venous lactate at the end of cooling and higher oxygen delivery rates were significantly associated with better outcome. Logistic regression showed that the oxygen consumption/kg at the end of cooling was the only predictor of mortality (P=0.046). Animals with an oxygen consumption/kg rate less than 1.43 ml/min per kg at the end of cooling had a mortality rate of 28%, whereas it was 50% among animals with an oxygen consumption/kg rate higher or equal to 1.43 ml/min per kg (P=0.020). The latter had even an increased 1-day mortality rate (40% vs. 26%) (P not significant). The mortality rate after anesthesia induction with ketamine plus 100% of oxygen was 38%, 45% after anesthesia induction with ketamine plus 35% oxygen, and 53% after anesthesia with medetomidine plus 35% oxygen (P not significant). Parameters of oxyhemodynamics should be monitored especially from the induction of anesthesia to the end of cooling before a 75-min period of HCA. The use of medetomidine and/or 35% of oxygen at induction of anesthesia should be avoided in favor of ketamine plus 100% of oxygen.European Journal of Cardio-Thoracic Surgery 11/2001; 20(4):803-10. · 2.55 Impact Factor
