bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduced isoflurane consumption with bispectral index monitoring
Authors: Guignard B. , Coste C. , Menigaux C. , Chauvin M. 
Published: March 2003

Background: Bispectral index (BIS) monitoring has been found to decrease the requirements for propofol, sevoflurane and desflurane and to improve recovery. We wanted to assess the effect of BIS monitoring on intraoperative isoflurane utilisation, and the early recovery profile.Methods: Eighty patients undergoing various surgical procedures were studied. In the first phase of the study, patients were anaesthetised without the use of BIS, the anaesthetists being blinded to the BIS readings, and isoflurane being administered according to standard clinical practice (control group). In a second phase, isoflurane was titrated to maintain a BIS value between 40 and 60 during surgery, and then 60–70 during 15 min prior to the end of surgery (BIS group). Isoflurane consumption was measured. Recovery times and the time to achieve a modified Aldrete score of 9 were recorded.Results: Despite similar mean BIS levels during maintenance of anaesthesia, the cumulative time spent with BIS values between 40 and 60 during maintenance of anaesthesia was significantly longer in the BIS group as compared with the control group (P<0.001). The isoflurane usage in the BIS group was 12–25% lower than in the control group (P<0.05). The time to awakening and extubation were comparable in the two groups. Although the patients were less sedated (P<0.01) during the three postoperative hours in the BIS (vs. control) group, no significant differences were observed in the time to obtain an Aldrete score of 9.Conclusion: The addition of BIS to standard monitoring decreases isoflurane consumption. However, we found only a small advantage in using BIS with respect to recovery from isoflurane anaesthesia.
Postoperative tracheal extubation after orthotopic liver transplantation
Authors: Glanemann M. , Langrehr J. , Kaisers U. , Schenk R. , Müller A. , Stange B. , Neumann U. , Bechstein W.‐O. , Falke K. , Neuhaus P. 
Published: March 2003

Background:The duration of postoperative mechanical ventilation and its influence on pulmonary function in liver transplant recipients is still debated controversially.Methods:We retrospectively analyzed the incidence of immediate tracheal extubation, prolonged mechanical ventilation (>24 h following surgery), and episodes of reintubation in 546 patients who underwent orthotopic liver transplantation (OLT) at our institution.Results:Immediate tracheal extubation in the operating theater was achieved in 18.7% of patients, and prolonged mechanical ventilation was required by 11.2% of patients. In these, median time of extubation was 49.5 h, whereas the remaining 70.1% of patients required ventilation support for a median 5 h after OLT. As risk factors for prolonged mechanical ventilation we identified the indications of acute liver failure and retransplantation, as well as factors such as mechanical ventilation prior to OLT, massive intraoperative bleeding, and severe reperfusion injury of the liver graft. The incidence of reintubation was 8.8% in patients who were immediately extubated following surgery, and 13.1% in patients who underwent extubation within 24 h. The incidence was significantly increased in patients requiring prolonged mechanical ventilation (36.1%).Conclusions:Immediate tracheal extubation was safe and well tolerated. The incidence of reintubation was not increased when compared to patients in whom extubation succeeded later. However, special attention should be given to transplant recipients presenting in reduced clinical condition at the time of OLT, undergoing complicated surgery, or receiving liver allografts with severe reperfusion injury because of an increased risk for prolonged mechanical ventilation.
Postoperative intensive care admittance: The role of tobacco smoking
Authors: Møller A. M. , Maaløe R. , Pedersen T. 
Published: March 2003

Background: Smokers have been shown to have increased risk of intraoperative pulmonary complications and of a wide range of postoperative complications, but an increased risk of postoperative intensive care admittance has not yet been described. The aim of this study was to estimate the risk of pulmonary complications and postoperative intensive care admittance in smokers and non‐smokers in a general and orthopaedic surgical population.Methods: A total of 4725 surgical patients were assessed. The following information was noted: age, sex and smoking status, history of heart and lung disease, ASA classification, type of anaesthesia, intensive care admittance and postoperative pulmonary or cardiovascular complications. A logistic regression model was used to determine the probability of intensive care admittance and pulmonary complications as a function of smoking status, age, and chronic heart and lung disease.Results: Of the patients, 39.9% were smokers, 45.5% were non‐smokers and in 14.6% of the cases smoking status was unspecified. Postoperative intensive care admittance and pulmonary complications were found in 2.0% and 4.3% of the patients, respectively. Non‐smokers were more often female (P<0.01), and smokers had a higher incidence of emergency surgical procedures (P<0.05). When applying multiple regression analysis, we found that smoking, age >65 years, and a history of chronic lung disease increased the risk of unplanned intensive care admittance (odds ratio 1.55, 12.52 and 2.73).Conclusion: Our results indicate a relationship between a history of tobacco smoking and postoperative intensive care admittance.
Modelling of hypoxaemia after gynaecological laparotomy
Authors: Kjærgaard S. , Rees S. E. , Nielsen J. A. , Freundlich M. , Thorgaard P. , Andreassen S. 
Published: March 2003

Background: Late postoperative arterial hypoxaemia is common after major surgery, and may contribute to cardiovascular, cerebral or wound complications. This study investigates the time course of hypoxaemia following gynaecological laparotomy, and estimates parameters of mathematical models of pulmonary gas exchange to describe hypoxaemia.Methods: Twelve patients were studied on four occasions; preoperatively, 2, 8 and 48 h after surgery. On each occasion inspired oxygen fraction (FIO2) was varied, changing end‐expired oxygen fraction (FEO2) to achieve arterial oxygen saturations (SaO2) ranging from 90% to 100%. Measurements of ventilation and blood gases were taken. Oxygenation was characterized plotting FEO2 against SaO2. The shape and position of the FEO2/SaO2 curve was described using two mathematical models including parameters describing gas exchange: either shunt and resistance to oxygen diffusion (Rdiff); or shunt and asymmetry of ventilation–perfusion (fA2).Results: Two hours after surgery SaO2 was reduced from 97.5%±1.2% (mean±SD) to 93.8%±2.7% (mean±SD) (P<0.001). Values of shunt, Rdiff and fA2 were significantly changed at 2 and 8 h postoperatively. Forty‐eight hours postoperatively Rdiff and fA2 were still significantly changed.Conclusion: Oxygenation in 12 patients preoperatively, 2, 8 and 48 h after gynaecological laparotomy is described. Two patients were hypoxaemic (SaO2 <92%) 48 h postoperatively. When two different models of oxygen transport are fitted to patient data, high values of Rdiff or low values of fA2 describe the right shift in the FEO2/SaO2 curve seen in patients with oxygenation problems. These models fit patient data identically, and may be useful in quantifying postoperative hypoxaemia.
Influence of colloid fluids on polymorphonuclear granulocyte function in vivo
Authors: Engel J. M. , Welters I. , Rupp M. , Langefeld T. , Ruwoldt R. , Menges T. , Hempelmann G. 
Published: March 2003

Background: Granulocytes have a role in the immediate immune response. In a previous investigation we could demonstrate in vitro a moderate increase of the complement receptors CR1 (CD35) and CR3 (CD11b/CD18) on the surface of polymorphonuclear neutrophils (PMN) after incubation of whole blood with colloids. To elucidate the clinical significance, we investigated if these changes were also present in vivo.Methods: The study was performed prior to anaesthesia for orthopaedic surgery. A total of 60 ASA‐I patients was evaluated. Patients received in a randomised manner 7 mL/kg of the following solutions: human albumin 5% (HA), gelatine 4% (GEL), hydroxyethylstarch solution 6% with MW 200 000 Da, degree of substitution 0.5 (HES), or Ringer’s solution. Prior to the infusion, at the end (30 min) and again 30 min later, blood samples were taken. Blood was incubated with fluorescein‐conjugated monoclonal antibodies (CD11b, CD16, CD35, CD62L) and analysed with flow cytometry.Results: HA, GEL, HES, and Ringer’s solution failed to induce significant differences in the expression of complement receptors CR1 (CD35) and CR3 (CD11b/CD18), Fcγ receptor IIIb (CD16), and of L‐selectin (CD62L) receptor on the surface of PMN.Conclusions: Application of colloids like HA, GEL, or HES in moderate amounts shows no short‐term effect on adhesion or activation molecules on granulocytes. However, in high doses, infused in situations such as multiple trauma and sepsis, the consequences on the function of PMN may be speculative and require further investigations.
An outcome study of severe traumatic head injury using the “Lund therapy” with low‐dose prostacyclin
Authors: Naredi S. , Olivecrona M. , Lindgren C. , Östlund A. L. , Grände P.‐O. , Koskinen L. O. D. 
Published: March 2003

Background: There are two independent head injury outcome studies using the “Lund concept”, and both showed a mortality rate of about 10%, and a favourable outcome (Glasgow outcome scale, GOS 4 and 5) of about 70%. The Lund concept aims at controlling intracranial pressure, and improving microcirculation around contusions. Intracranial pressure is controlled by maintaining a normal colloid osmotic pressure and reducing the hydrostatic capillary pressure. Microcirculation is improved by ensuring strict normovolaemia and reducing sympathetic discharge. The endogenous substance prostacyclin with its antiaggregatory/antiadhesive effects may further improve microcirculation, which finds support from a microdialysis‐based clinical study and an experimental brain trauma study. The present clinical outcome study aims at evaluating whether the previously obtained good outcome with the Lund therapy can be reproduced, and whether the addition of prostacyclin has any adverse side‐effects.Methods: All 31 consecutive patients with severe head injury, Glasgow coma scale (GCS) ≤8, admitted to the University Hospital of Umeå during 1998 were included. The Lund therapy including prostacyclin infusion for the first three days at a dose of 0.5 ng kg−1 min−1. Outcome was evaluated according to the GOS >10 months after the injury.Results: One patient died, another suffered vegetative state and 7 severe disability. Of the 22 patients with favourable outcome, 19 showed good recovery and 3 moderate disability. No adverse side‐effects of prostacyclin were observed.Conclusion: The outcome results from previous studies using the Lund therapy were reproduced, and no adverse side‐effects of low‐dose prostacyclin were observed.
Cardiopulmonary bypass elicits a pro‐ and anti‐inflammatory cytokine response and impaired neutrophil chemotaxis in neonatal pigs
Authors: Brix‐Christensen V. , Petersen T. K. , Ravn H. B. , Hjortdal V. E. , Andersen N. T. , Tønnesen E. 
Published: March 2003

Background: Cardiopulmonary bypass (CPB) induces a systemic inflammatory response and organ dysfunction, especially in children. Plasma concentration of inflammatory markers are increased in response to the trauma of cardiac surgery and CPB. The aim of the present study was to investigate whether the CPB procedure in itself elicits increased levels of inflammatory markers in neonatal pigs.Methods: The inflammatory response was measured in piglets undergoing sternotomy alone (sham group, n=13) or sternotomy and CPB (n=14). Inflammatory mediators were measured at baseline and at fixed time‐points during and after CPB. IL‐8, IL‐10 and TNF‐α levels and C‐reactive protein (CRP) concentrations were measured in plasma samples. Polymorphonuclear neutrophils (PMN) chemotaxis was measured ex vivo, and CD‐18 expression using an immunofluorescence technique.Results: Immediately after the CPB procedure increased IL‐8 levels were found in the CPB group, but not in sham operated animals (P=0.005). Simultaneously, a marked IL‐10 response was measured in the CPB group. Concurrently, PMN chemotaxis decreased in CPB animals but not in the sham group (P=0.04). CD‐18 expression and CRP levels were not significantly different between groups and TNF‐α showed no changes in either group. The chemotactic response did not correlate with plasma IL‐8 or IL‐10, nor with CD‐18 expression.Conclusion: The CPB procedure elicited a systemic inflammatory response in terms of significantly elevated plasma levels of IL‐8 and IL‐10. Furthermore, a temporary and simultaneous decrease in PMN chemotaxis was observed immediately after CPB.
Changes in circulating blood volume after infusion of hydroxyethyl starch 6% in critically ill patients
Authors: Christensen P. , Andersson J. , Rasmussen S. E. , Andersen P. K. , Henneberg S. W. 
Published: March 2003

Background: The cardiovascular response to a volume challenge with hydroxyethyl starch (HES) (200/0.5) 6% depends on the relation between the volume of HES 6% infused and the expansion of the blood volume in critically ill patients. However, only relatively limited data exist on the plasma expanding effect of infusion of HES 6% in critically ill patients. The purpose of the study was to evaluate the variation in the expansion of the circulating blood volume (CBV) in critically ill patients after infusion of 500 ml of colloid (HES (200/0.5) 6%) using the carbon monoxide method.Methods: In 20 consecutive patients admitted to the ICU requiring mechanical ventilation and volume expansion, 500 ml of HES (200/0.5) 6% was infused. The CBV was measured immediately before the infusion, 10 min after completing the infusion and then hourly for 8 h.Results: The median volume expansion immediately after infusion was 470 ml (range 270 ml to 840 ml). The corresponding values after 4 h and 8 h were 265 ml (range −30 ml to 460 ml) and 120 ml (range −210 ml to 360 ml), respectively. The increase in CBV was only statistically significant for 4 h. The coefficient of variation of the method for estimation of CBV was 3.6%.Conclusions: The large interindividual variation of the volume expansion after infusion of HES 6% in critically ill patients illustrates one of the difficulties in optimizing colloid therapy and interpretating the changes in hemodynamic variables after a colloid challenge.
Effects of dopamine on porcine myocardial action potentials and contractions at 37 °C and 32 °C
Authors: Roscher R. , Arlock P. , Sjöberg T. , Steen S. 
Published: March 2003

Background: Little information exists on the effects of drugs with cardiovascular action in hypothermia, and some findings have indicated paradoxic effects of dopamine in this setting. As we have not found any data on the electrophysiologic and contractile effects of dopamine on the heart in hypothermia, we decided to study this in pig myocardium, since pigs have a cardiovascular system more similar to that of humans than other animals.Methods: Excised muscle strips from pig ventricular septum were mounted in an organ bath. After 45 min of equilibration at 37 °C or 32 °C, resting and action potentials, time to peak contraction and contractile force were recorded during pacing with a frequency of 60/min. Dopamine at 4 μM or 8 μM was added and new recordings were made after 15 min.Results: Cooling to 32 °C caused a prolongation of contraction by 48% and the contractile force increased by 39%. The membrane action potential duration at 50% and 90% repolarization levels increased at 32 °C by 28% and 16% respectively. Dopamine significantly (P<0.05) increased the contractile force and membrane action potential duration at 50% and 90% repolarization levels both in normothermia and in hypothermia, whereas the duration of the contraction was not significantly changed.Conclusion: Cooling to 32 °C significantly prolongs the myocardial action potential and the contraction duration. Dopamine increases the contractile force and prolongs the action potential both at 37 °C and at 32 °C.
Spasmolytic effect of magnesium sulfate on serotonin‐induced pulmonary hypertension and bronchoconstriction in dogs
Authors: Yoshioka H. , Hirota K. , Sato T. , Hashimoto Y. , Ishihara H. , Matsuki A. 
Published: March 2003

Background: Magnesium (Mg2+) has relaxant effects on histamine‐induced bronchoconstriction. In addition, Mg2+ has been reported to reduce vascular smooth muscle tone and be clinically useful for treatment of persistent pulmonary hypertension of the newborn. In this study, we evaluated the relaxant effect of Mg2+ on serotonin (5HT)‐induced bronchoconstriction and pulmonary hypertension.Methods: Seven mongrel dogs were anesthetized with pentobarbital (30 mg · kg−1+2 mg · kg−1 · h−1) and paralyzed by pancuronium (0.2 mg · kg−1 · h−1). Bronchoconstriction and pulmonary hypertension were elicited with 5HT (10 μg · kg−1+1 mg · kg−1 · h−1). Airway caliber was evaluated by changes in bronchial cross‐sectional area (BCA) of the 3rd bronchial bifurcation measured by a fiberoptic bronchoscope method as previously reported. Pulmonary hypertension was assessed by changes in pulmonary vascular resistance (PVR). The BCA and PVR were expressed as per cent of the basal level. Thirty minutes after start of 5HT infusion, magnesium sulfate (MgSO4): 0 (saline), 1, 10, 100 and 1000 μmol · kg−1 was given iv. Arterial blood was also collected to measure plasma level of Mg2+ and catecholamines.Results: 5HT increased %PVR to 163±25% and decreased % BCA by 39.2±4.5%. Plasma level of Mg2+ following MgSO4 1000 μmol · kg−1 iv exceeded its toxic level. The ED50s of MgSO4 (dose producing 50% relaxation of maximal constriction) was 47.8 μmol · kg−1 and 1.09 mmol · kg−1 for pulmonary hypertension and bronchoconstriction, respectively. The ratio of %PVR to %SVR was about 1.0 after MgSO4 0–100 μmol · kg−1 iv, although the ratio significantly increased after 1000 μmol · kg−1 iv.Conclusion: In dogs, 5HT‐induced pulmonary hypertension but not bronchoconstriction was significantly reduced by an iv bolus of MgSO4, resulting in a plasma concentration within the assumed therapeutic level.
No effect of L‐arginine supplementation on pulmonary endothelial dysfunction after cardiopulmonary bypass
Authors: Angdin M. , Settergren G. , Liska J. , Astudillo R. 
Published: March 2003

Background: Acetylcholine is an endothelium‐dependent vasodilator through the L‐arginine‐nitric oxide pathway. After ischemia‐reperfusion this effect is attenuated, also demonstrated in the pulmonary circulation after cardiopulmonary bypass. Administration of L‐arginine has been shown to have a protective effect on endothelial function in reperfusion injury. The aim of the current study was to test the possible effect of L‐arginine on the acetylcholine reactivity in the pulmonary circulation after cardiopulmonary bypass.Methods: Thirty‐five patients with ischemic and/or valvular heart disease were investigated in a randomized, double‐blinded, placebo‐controlled study. The patients were divided into three groups. Group 1: high dose L‐arginine (n=10), group 2: low dose L‐arginine (n=10), group 3: placebo, no L‐arginine, (n=15). The acetylcholine reactivity was tested with measurements of pulmonary vascular resistance before surgery and 1, 2 and 3–4 h after cardiopulmonary bypass.Results: After cardiopulmonary bypass an attenuation of the acetylcholine reactivity over time was observed in all groups, with no differences between groups.Conclusion: In the current study L‐arginine had no protective effect on the pulmonary endothelium after cardiopulmonary bypass, measured as reactivity to an infusion of acetylcholine.
Etomidate and thiopental inhibit platelet function in patients undergoing infrainguinal vascular surgery
Authors: Gries A. , Weis S. , Herr A. , Graf B. M. , Seelos R. , Martin E. , Böhrer H. 
Published: March 2003

Background: Postoperative platelet hyperaggregability following general anesthesia has been reported in patients undergoing major vascular surgery. In contrast, since anesthetic agents inhibited platelet function both in vitro and in vivo, an increased risk for postoperative bleedings due to prolonged platelet dysfunction has been discussed. Nevertheless, data describing platelet‐affecting properties of induction agents such as etomidate and thiopental in patients undergoing major vascular surgery are lacking.Methods: Platelet function was determined at 0, 2, 20, and 200 μg/ml thiopental and at 0, 0.2, 2, 20 μg/ml etomidate in vitro in blood samples drawn from 16 patients suffering from severe occlusive arterial disease. In addition, 30 patients undergoing vascular surgery were investigated before (PRE) and after anesthesia induction (T0) either with etomidate (ETO group, n=16) or thiopental (THIO group, n=14), and 2 h after the beginning of surgery (T2). Platelet function was determined according to platelet aggregation, in vitro bleeding time, and flow cytometric measurements.Results: In vitro, P‐selectin expression was inhibited by etomidate at 2 and 20 μg/ml (−28% and −38%, respectively) and also by thiopental at 200 μg/ml (−27%). In patients undergoing vascular surgery, anesthesia induction in the ETO group resulted in a 31% prolongation of the in vitro bleeding time and an inhibition of ADP‐ and collagen‐induced platelet aggregation (−30% and −17%, respectively) and of P‐selectin expression (−25%) at T0. In the THIO group, only ADP‐induced platelet aggregation was affected (−16%). At T2, all parameters had reached PRE level again in both groups. Furthermore, in comparison with the THIO group, operation time was significantly prolonged and transfusion volume was significantly increased in the ETO group. In addition, platelet count and hematocrit significantly decreased at T2, whereas levels of tPA, PAI‐1, fibrinogen and antithrombin III and partial thromboplastin time remained unchanged in both groups during the study period.Conclusions: In the present study, etomidate and, to a minor extent, thiopental offered significant platelet inhibitory properties. Anesthetic‐induced platelet inhibition may lead to higher transfusion rates and prolonged operation times. Therefore, anesthetic‐related platelet inhibitory properties should be considered when searching for the anesthetic agent of choice, especially in patients with compromised hemostasis and co‐existing bleeding disorders.