bluuebunny/crossref_metadata_2025_split huggingface dataset:
Haemodynamic and metabolic changes induced by repeated episodes of hypoxia in pigs
Authors: Licker M. , Schweizer A. , Hohn L. , Morel D. R. 
Published: January 2009

Background: Repeated hypoxia and surgical trauma trigger a potent neuroendocrine response and their association is thought to play a pivotal role in the pathogenesis of multi‐organ dysfunction. We investigated the cardiovascular and metabolic responses to repeated acute hypoxia in anaesthetised and surgically instrumented pigs.Methods: Under ketamine‐midazolam anaesthesia, 15 pigs were surgically instrumented for measurements of cardiac output, vascular pressures and organ blood flows. Lactate production and O2 uptake were determined in the brain, liver, kidney and intestine. Ten animals were subjected to two 12‐min periods of ventilatory hypoxia (FIO2=7%) followed by re‐oxygenation and 5 animals underwent 120–min normoxic ventilation (Control group).Results: Both hypoxic challenges produced a comparable release of catecholamines that was associated with increased cardiac output and redistribution of blood flow away from the intestinal and renal areas towards the brain and the liver; O2 uptake was markedly reduced in the intestine (– 56 ± 10%, P < 0.05) and least affected in the brain and the kidney (– 19±12% and — 23±21%, respectively). During the second hypoxic test, lethal cardiovascular depression occurred in 5 animals; these non‐survivors demonstrated impaired hyperdynamic response and incomplete recovery of intestinal O2 uptake during the first hypoxia/reoxygenation test. In the Control group, normoxic ventilation was not associated with significant haemodynamic and metabolic changes.Conclusion: Intraoperative hypoxia causes marked heterogeneity in organ blood flow and metabolism. The inability to develop a hyperdynamic cardiovascular response during a first hypoxic event, as well as a persistent intestinal O2 debt following re‐oxygenation, predict the occurrence of death during the second hypoxic insult.
Renal dysfunction after total knee replacement is not aggravated by bone cement
Authors: Nergelius G. , Lidgren L. , Grubb A. , Vinge E. 
Published: January 2009

Background: Total knee replacement (TKR) has been associated with postoperative renal dysfunction. The use of monomeric methylmethacrylate (MMA) bone cement causes hypotension by several mechanisms.Methods: In 30 patients undergoing TKR with (n=16), or without (n = 14) bone cement, serum levels of creatinine, cystatin C and creatine kinase (CK) and urinary levels of creatinine and markers for glomerular (albumin, IgG) and tubular (protein HC) function were recorded preoperatively and on days 1, 2, 4 and 8 postoperatively.Results: There were no changes in serum creatinine. Both groups had a transient, 5‐fold rise in CK and a continuous increase in cystatin C. The urinary concentration of proteins increased postoperatively with a peak in the glomerular markers on day 1 and in the tubular marker on day 2. There were no significant differences in proteinuria between the groups. The 95% CIs for the difference in the means of the AUCs of the logarithmically transformed values for the proteins were never more than 19%. On day 8 all proteins had returned to their preoperative levels.Conclusion: Postoperatively, there was a transient increased leakage of proteins, indicating glomerular and tubular dysfunction. This was not influenced by the use of MMA bone cement.
Effects of ketorolac and dextran‐70 alone and in combination on haemostasis
Authors: Power I. , Noble D. W. , Winter A. , Greer I. A. 
Published: January 2009

Background: Dextran may be used in surgical patients for thromboprophylaxis or volume expansion along with ketorolac, a nonsteroidal anti‐inflammatory drug, for analgesia. As these two agents can influence the haemostatic system at different sites, it is important to demonstrate that there is no adverse haemostatic interaction between them.Methods: The haemostatic interaction between intravenous dextran‐70 and intramuscular ketorolac was assessed in a double‐blind, randomised, crossover study of healthy male volunteers each given all four combinations of ketorolac/placebo intramuscularly and dextran/placebo intravenously. The effect of ketorolac and dextran on haemostasis was assessed by the following techniques: skin bleeding time, in vitro platelet aggregation function, whole blood thromboxane generation, von Willebrand factor antigen, factor VIII coagulant activity and tissue plasminogen activator. The results were analysed for the effects of ketorolac and dextran and for any evidence of an interaction.Results: Ketorolac inhibited platelet function and thromboxane generation. Dextran reduced factor VIII coagulant activity. Neither agent had a significant effect on bleeding time, von Willebrand factor or tissue plasminogen activator. There was only evidence of a small but statistically significant interaction between ketorolac and dextran on thromboxane generation. There was no evidence of any other interaction of ketorolac with dextran. Conclusion: This interaction on thromboxane generation is unlikely to be of clinical significance as substantial inhibition of thromboxane generation occurs with ketorolac alone.
Volatile anaesthetics reduce adhesion of blood platelets under low‐flow conditions in the coronary system of isolated guinea pig hearts
Authors: Heindl B. , Becker B. F. , Zahler S. , Conzen P. F. 
Published: January 2009

Background: Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.Methods: Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low‐flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low‐flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in‐ and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.Results: At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low‐flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P<0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.Conclusion: Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.
Surgeon's experience as a factor for emetic sequelae after middle ear surgery
Authors: Honkavaara P. , Pyykkö I. 
Published: January 2009

Purpose: To test the hypothesis that an experienced surgeon is associated with less postoperative nausea and vomiting (PONV).Methods: A post hoc analysis was done on the data of 167 patients from 3 randomized studies on the prevention of PONV, with transdermal scopolamine, ondansetron and propofol, in middle ear surgery under general anaesthesia.Results: The patients in the residents' group suffered more from PONV (69% vs. 42%, P<0.01) and from retching or vomiting (52% vs. 23%, P<0.001) than those in the specialists' group. The proportion of patients needing droperidol was also higher in the residents' group (66% vs. 27%, P<0.001). The durations of anaesthesia and surgery seemed to correlate positively with PONV. In matched‐pair analysis, residentship was confirmed as a risk factor for emetic symptoms. In the residents' group, prophylaxis of PONV resulted in a decrease in retching and vomiting from 71% to 29% (P<0.01), and in patients needing droperidol from 87% to 46% (P<0.01).Conclusion: The patients operated by residents need more aggressive prophylaxis for PONV than those operated by specialists in middle ear surgery.
Prophylactic antiemetic therapy with granisetron‐dexamethasone combination in women undergoing breast surgery
Authors: Fujii Y. , Tanaka H. , Toyooka H. 
Published: January 2009

Background: Dexamethasone decreases chemotherapy‐induced emesis when added to an antiemetic regimen. This study was undertaken to evaluate the efficacy of granisetron‐dexamethasone combination for the prevention of postoperative nausea and vomiting (PONV) in female patients undergoing general anaesthesia for breast surgery.Methods: In a randomized, double‐blind manner, 135 ASA I patients, aged 40–65 years, were assigned to receive placebo (saline), granisetron 40 μg · kg−1 or granisetron 40 μg · kg−1 plus dexamethasone 8 mg i.v. (n=45 of each) immediately before the induction of anaesthesia. A standard general anaesthetic technique and postoperative analgesia were used. The PONV and safety assessments were performed continuously during the first 3 h (0–3 h) and the next 21 h (3–24 h) after anaesthesia.Results: A complete response, defined as no PONV and no administration of rescue antiemetic medication, during 0–3 h after anaesthesia was 51%, 82% and 96% in patients who had received placebo, granisetron and granisetron‐dexamethasone combination, respectively; the corresponding incidence during 3–24 h after anaesthesia was 56%, 84% and 98% (P<0.05; overall Fisher's exact probability test). No clinically important adverse events were observed in any of the groups.Conclusion: Prophylactic use of granisetron‐dexamethasone combination is more effective than granisetron alone for the prevention of PONV after breast surgery.
Responses of respiratory drive and breathing pattern to inspiratory loading during nitrous oxide and isoflurane sedation
Authors: ÖStlund A. , Linnarsson D. 
Published: January 2009

Background: Increased inspiratory resistance in combination with mild gas narcosis is common during recovery after a general anesthesia, but there are only few previous studies on inspiratory loading during subanesthetic gas narcosis.Methods: Responses of respiratory drive (central inspiratory activity P0.1) and ventilatory pattern to an inspiratory threshold load of –6 cm H2O were studied in 16 healthy subjects during mild subanesthetic gas narcosis. One group (n=9) was exposed to 13, 26 and 39% nitrous oxide (N2O) and air control (Group N). Another group (n=7) was exposed to 0.1, 0.2 and 0.3% isoflurane and air control (Group I). Measurements were done after 1 min adaptation to the load.Results: Nitrous oxide and isoflurane had no effect on respiratory drive and VT either during unloaded breathing or during inspiratory threshold loading. Across all gas concentrations (including 0% control), inspiratory threshold loading resulted in significant P0.1 increases, amounting to 62% in group N and 38% in group I. At the same time VT decreased by 11 and 12%, respectively. A significantly increased end‐expired CO2 and decreased minute volume compared to air control was found during isoflurane inhalation but could be ascribed to normalization of the hyperventilation in the control situation.Conclusions: It is concluded that the steady‐state ventilatory responses to loading, consisting of increased P0.1 and decreased VT, are maintained during inhalation of subanesthetic doses of N2O (0.13–0.38 MAC) and isoflurane (0.09–0.26 MAC).
Comparison of the haemodynamic actions of desflurane/N2O and isoflurane/N2O anaesthesia in vascular surgical patients
Authors: Zubicki A. , Gostin X. , Miclea D. , Rrou B. , Buy E. , Richer C. , Coriat P. 
Published: January 2009

Background: The purpose of this study was to compare heart rate and arterial blood pressure response to desflurane/N2O vs isoflurane/N2O anaesthesia in a randomised clinical trial performed in patients before vascular surgery.Methods: To evaluate associated changes in the autonomic nervous system with maintenance of anaesthesia, we used power spectral analysis (PSA) of heart rate and blood pressure and measured plasma catecholamine concentrations. Twenty‐five patients whose trachea had been intubated after propofol induction were given either desflurane or isoflurane at 1 and 1.5 MAC in N2O (60%) in a random manner.Results: At an anaesthetic depth of up to 1.5 MAC, arterial blood pressure, indices of sympathetic activity derived from PSA, decreased with both anaesthetics, while heart rate and plasma catecholamine concentrations did not significantly change. Plasma renin activity significantly increased at 1.5 MAC anaesthesia in both groups.Conclusions: We conclude that sympathetic hyperactivity previously reported during desflurane anaesthesia in healthy volunteers is not frequent in clinical practice in elderly vascular surgical patients under desflurane/N2O anaesthesia, since it occurs at an anaesthetic depth which cannot be reached in these patients because of the lowering arterial blood pressure effects of desflurane, which are similar to those of isoflurane.
Negative pressure ventilation vs. spontaneous assisted ventilation during rigid bronchoscopy: A controlled randomised trial
Authors: Natalini G. , Cavaliere S. , Vitacca M. , Amicucci G. , Ambrosino N. , Candiani A. 
Published: January 2009

Background: Ventilation during interventional rigid bronchoscopy (IRB) under general anaesthesia (jet ventilation, positive pressure ventilation and spontaneous assisted ventilation) may offer some difficulties. This study compares the effectiveness during IRB of intermittent negative pressure ventilation (INPV) and spontaneous assisted ventilation (SAV).Methods: Thirty‐eight patients submitted to IRB were randomised into two groups: SAV or INPV. All patients received a total intravenous anaesthesia; INPV patients were paralysed. Pre‐and intra‐operative arterial blood gases and O2 flow through a rigid bronchoscope were assessed. The endoscopist applying a subjective score evaluated the operating conditions.Results: Patients of the INPV group, as compared to the SAV group, required a lower dosage of fentanyl (2.6 ± 1.8 (μg · kg−1· h−1 vs. 6.6 ± 4.8 μg · kg−1· h−1), a lower O2 supply (3.3 ± 2.8 1/min vs. 11.6 ± 3.4 1/min), a shorter recovery time (5.4 ± 2.9 min vs. 9.8 ± 7.1 min) and no manually assisted ventilation (0 ± 0 vs. 1 ± 1.1 nd̀/procedure). Intraoperative PaCO2 was higher in the SAV (8.1 ± 1.3 kPa) than in the INPV group (5.0 ± 1.6 kPa) and intraoperative pH differed in the two groups (7.26 ± 0.05, SAV vs. 7.47 ± 0.08, INPV). Operating conditions, as assessed by a subjective score, were considered better with INPV than with SAV (4.9 vs. 4.3).Conclusions: As compared to SAV, INPV in paralysed patients during IRB reduces administration of opioids, shortens recovery time, prevents respiratory acidosis, excludes the need for manually assisted ventilation, reduces 02 need and affords optimal surgical conditions. INPV appears a safe, non‐invasive and effective ventilatory management during IRB.
Postdural puncture headache and transient neurologic symptoms in children after spinal anaesthesia using cutting and pencil point paediatric spinal needles
Authors: Kokki H. , Hendolin H. , Turunen M. 
Published: January 2009

Background: In the last decade the use of spinal anaesthesia (SA) in paediatric anaesthesia has increased. In adults, pencil point spinal needles are supposed to be less traumatic and hence to be superior compared with cutting point needles in respect of postpuncture complaints. In children, the use of spinal needles with a special tip design have not been compared. The aim of this study was to study the clinical utility and postpuncture characteristics of four newly designed spinal needles in paediatric surgery.Methods: In this open‐randomised, parallel groups, prospective study we compared the puncture quality, success rate and post‐puncture characteristics in 200 children aged 2 to 128 months. Two cutting point needles; a 50‐mm‐long 25G Quincke and a 25‐mm‐long 26G Atraucan were compared with two pencil point needles; a 37‐mm‐long 27G Whitacre and a 35‐mm‐long 24G Sprotte. The children were premedicated with oral diazepam and those anxious or uncomfortable after premedication were sedated with i.v. thiopentone or propofol. Bupivacaine 5 mg ml−1 0.3–0.5 mg kg−1 was used for the SA.Results: The spinal puncture was successful with one or two skin punctures in 96% of children. The cutting point needles were easier to insert through the skin and ligaments (P=0.001) but the pencil point needles gave a better (P=0.001) indication of the dural passage. The success rate of the SA was 91% without differences between the needles. Five patients were given general anaesthesia and 13 children a single dose of i.v. fentanyl/sedative. The spinal block was completed in less than 3 min in 96% of the cases without differences between the needles.Seventeen children developed a headache, 10 of which were classified as a postdural puncture headache (PDPH), 3 with the Sprotte, 3 with the Quincke and 4 with the Atraucan needles. The youngest child developing PDPH was a 12‐month‐old boy. Eight of the PDPH were mild and 2 moderate. Ten children developed a low back pain, 2–3 in each study group. Three children in the pencil point groups developed signs of transient radicular irritation.Conclusion: SA using bupivacaine and the study needles produced smooth and safe anaesthesia for paediatric surgery with a high success rate. PDPH after SA is as common in children (5%) as in adults although most often mild and short lasting. SA using bupivacaine can cause transient radicular irritation.
Unilateral spinal anaesthesia with hyperbaric bupivacaine
Authors: Esmaoĝlu A. , Boyaci A. , Ersoy Ö. , Güler G. , Talo R. , Tercan E. 
Published: January 2009

Background: The dosage of local anaesthetic and the time the patient must be kept in the lateral decubitus position for a unilateral spinal anaesthesia is not known. The aim of this study was to determine the ideal dosage of hyperbaric bupivacaine and the time required for the lateral decubitus position for a unilateral spinal block.Methods: Ninety patients who were scheduled to receive spinal block for surgery in the lower extremity were randomised into 9 groups (n=10). The spinal block was performed through the L4–L5 intervertebral space with the patient in the lateral decubitus position. Patients in groups Ia, Ib, Ic; IIa, IIb, IIc; IIIa, IIIb, IIIc received 1.5 ml of 0.5%, 2 ml of 0.5%, and 2.5 ml of 0.5% hyperbaric bupivacaine solutions, respectively. The patients were turned to the supine position for 5 min after the injection in groups Ia, IIa, IIIa, 10 min after the injection in groups Ib, IIb, IIIb, and 15 min after the injection in groups Ic, IIc, IIIc. The onset and regression of sensory and motor block were checked and compared between the dependent and non‐dependent sides in each group.Results: The rate of block progression of the non‐dependent side was higher in the groups receiving 2.5 ml 0.5% hyperbaric bupivacaine solution than in the other groups; at the same time the level of block was higher and the duration of block was longer. The incidence of hypotension was 10–20% in these groups. In the 2 ml 0.5% hyperbaric bupivacaine solution groups, a satisfactory block level and duration of anaesthesia for surgery was obtained. The rate of block progression to non‐dependent side in the groups receiving 1.5 ml of 0.5% hyperbaric bupivacaine solution was lower than the other groups, but the duration of block was shorter and the level of block was lower than the other groups.Conclusion: For unilateral spinal anaesthesia in lower extremity operations, 2ml 0.5% hyperbaric bupivacaine solution for operations above the knee and 1.5 ml 0.5% hyperbaric bupivacaine solution for operations below the knee and keeping the patients for 10 min in the lateral decubitus position were found to be appropriate.
Spreading pattern of epidurally administered contrast medium in rabbits
Authors: Kim Y. C. , Lim Y. J. , Lee S. C. 
Published: January 2009

Background: The aim of this study was to examine the precise spreading pattern of epidurally administered contrast medium with small increments of injection volume for determining both the exact volume of the dose required and the site of epidural injection according to different target segments of the spinal cord in a rabbit epidural model.Method: Following pentobarbital anesthesia, the epidural puncture was done surgically with a round‐tipped blunt hook. The tip of the epidural catheter was located at either the mid‐portion of T7 (T7 group, n=7) or T12 (T12 group, n=8). Injection of the contrast medium was started at 0.1 ml/kg and increased by 0.1 ml/kg up to a maximum of 0.6 ml/kg.Results: In both groups, the extent of spread increased continuously with increasing injected volume (T7 group: r2=0.91, P= 0.0001; T12 group: r2=0.86, P=0.0001) and the total spread of contrast medium was similar. However, the spread was not linearly volume dependent. The total number of segments (γ) through which the contrast medium spread during changes in its volume (χ) in the T7 and T12 groups was calculated as γ=4.0+41.8χ‐28.1χ2 and γ=0.2+57.7χ‐43.5χ2, respectively. The contrast medium spread in both rostral and caudal directions, equally from the catheter tip in the T7 group, whereas it spread rostrally about twice as far as it spread caudally in the T12 group (P<0.05).Conclusion: In rabbits, it is recommended that at the lower thoracic or lumbar segments the tip of the epidural catheter should be located 1–3 segments below the target segment because of more rostral spread. In the case of mid‐thoracic segments, however, placement at the target segment is recommended. In addition, a small titration of volume to achieve a particular range of epidural spread should be required.
Bactericidal activity of preservative‐free bupivacaine on microorganisms in the human skin flora
Authors: Sakuragi T. , Ishino H. , Dan K. 
Published: January 2009

Background: The rate at which the bactericidal activity of preservative‐free bupivacaine develops at body temperature and at room temperature is not known. We studied the bactericidal activity of preservative‐free bupivacaine on two strains of methicillin‐resistant Staphylococcus aureus (MRSA), two strains of methicillin‐susceptible S. aureus (MSSA), and each of Staphylococcus epidermidis and Escherichia coli.Methods: The pathogen was exposed to 0.5% bupivacaine for 1, 3, 6, 12, and 24 h at 37°C and room temperature. In addition, each strain of MRSA, MSSA, and S. epidermidis was exposed to distilled water, and 0.125%, 0.25%, 0.5%, and 0.75% bupivacaine at 37°C. The inocula from the suspensions were cultured for 48 h at 37°C.Results: The 1‐ through 24‐h exposures of 4 strains of S. aureus to 0.5% bupivacaine at room temperature reduced the colony count by 21.7%, 34.7%, 51.1%, 65.6%, and 81.1%, respectively, and the exposure at 37°C reduced the count by 34.1%, 50.8%, 66.3%, 94.5%, and 96.0%, respectively. The differences were significant at all exposure times (P<0.001, respectively). No organisms grew in the strain of E. coli after 24‐h exposure and in the strain of S. epidermidis after 12‐ and 24‐h exposures at 37°C. The percent change from controls in the strains of E. coli and S. epidermidis was significantly higher than that in the strains of S. aureus at all exposure times at room temperature and 37°C (P<0.0001, respectively). Higher concentrations of bupivacaine were associated with lower colony count.Conclusion: Our results show that preservative‐free bupivacaine possesses a temperature‐ and concentration‐dependent bactericidal activity, and S. aureus is more resistant to the bactericidal activity of bupivacaine than are S. epidermidis and E. coli.