bluuebunny/crossref_metadata_2025 huggingface dataset:
Pain and systematic reviews
Authors: Moore R. A.
Published: March 2003

There is a huge medical literature, with very large amounts of information. Some of that information is useful, some not. The task is to distil the information, apply quality filters, and place it into context so that we can use the knowledge we have with wisdom. The process of systematically reviewing the literature helps us generate solid, unbiased knowledge. Using appropriate tools, like numbers needed to treat (NNT), we can provide a solid basis to allow practitioners and their patients to make the best, and best informed, choices about their care.
Intraoperative epidural blockade prevents the increase in protein breakdown after abdominal surgery
Authors: Lattermann R. , Schricker T. , Wachter U. , Goertz A. , Georgieff M.
Published: March 2003

Background: The aim of this study was to investigate the effect of epidural blockade with bupivacaine, restricted to the intraoperative period, on protein catabolism after major abdominal surgery.

Methods: Fourteen patients undergoing cystoprostatectomy were randomly assigned to receive either general anaesthesia with isoflurane (control group, n=7) or a combination of general anaesthesia and epidural blockade with bupivacaine from segment T4 to S5 (epidural group, n=7). Rates of urea (Ra urea) and glucose production (Ra glucose) were measured three days before and three days after the operation using stable isotope tracers ([15N2]urea, [6,6‐2H2]glucose). Protein breakdown was calculated from the urea production rate. Plasma concentrations of metabolic substrates (urea, glucose, lactate, glycerol, amino acids) and hormones (insulin, glucagon, cortisol, adrenaline, noradrenaline) were also determined.

Results: Protein breakdown significantly increased after surgery in the control group (P<0.05), while it remained unaltered in the epidural group (control; 66 (54–76), epidural; 43 (29–58) mg · kg−1 · h−1, P<0.05, median (range)). Glucose plasma concentration and Ra glucose increased in both groups to a similar extent (P<0.05). Plasma concentration of branched chain amino acids decreased after epidural analgesia to a value significantly lower than in the control group (P<0.05). Glutamine plasma concentration decreased in the control group (P<0.05), but did not change in the epidural group. There were no differences in plasma concentrations of insulin, cortisol and catecholamines between the two groups. Glucagon plasma concentration in the epidural group was significantly lower than in the control group (P<0.05).

Conclusion: Intraoperative epidural blockade inhibits the increase in protein breakdown after abdominal surgery.
Acute effects of angiotensin II on myocardial performance
Authors: Broomé M. , Haney M. , Häggmark S. , Johansson G. , Åneman A. , Biber B.
Published: March 2003

Background: Specific angiotensin II (Ang II) receptors exist in many organs including peripheral blood vessels, cardiac myocytes and the central nervous system. This suggests multiple sites of actions for Ang II throughout the cardiovascular system. Cardiac effects of Ang II are not completely understood, though its prominent vasoconstrictor actions are well described. This study was designed to assess left ventricular function during administration of Ang II using relatively load‐independent methods in a whole‐animal model.

Methods: Ang II was infused in incremental doses (0–200 μg  ·  h−1) in anaesthetised instrumented pigs (n=10). Cardiac systolic and diastolic function were evaluated by analysis of the left ventricular pressure–volume relationship.

Results: Heart rate (HR), mean arterial pressure (MAP) and systemic vascular resistance (SVR) increased dose‐dependently with Ang II, while cardiac output (CO) remained unchanged. Systolic function indices, end‐systolic elastance (Ees) and preload recruitable stroke work (PRSW), demonstrated dose‐dependent increases. The diastolic function parameter tau (τ) did not change with increasing Ang II dose.

Conclusion: Ang II infusion caused increases in contractility indices in anaesthetised pigs in the doses used in this study. The mechanisms for these systolic function effects may be a direct myocardial effect or modulated through changes in autonomic nervous system activity.
Procalcitonin following elective partial liver resection – origin from the liver?*
Authors: Kretzschmar M. , Krüger A. , Schirrmeister W.
Published: March 2003

Background: The origin of the inflammatory peptide procalcitonin (PCT) is still unknown. In the present study PCT concentrations in arterial and hepatic‐venous blood were examined in patients undergoing elective partial liver resection (LR) using a fiberoptic pulmonary arterial catheter placed in a liver vein to obtain further information on the origin of PCT.

Methods: In 28 patients (21 male/7 female; average age of 58.8±8.8 years) undergoing LR, arterial and hepatic venous PCT concentrations were measured during 24 h perioperatively. The parallel blood withdrawals occurred immediately before the Pringle maneuver (Hx), 2 min, 1, 2, 6, 12, and 24 h after Hx. Over the whole period, the oxygen saturation in hepatic venous blood (ShvO2) was monitored. PCT concentrations were assayed by immunoluminometry.

Results: We observed a significant increase in PCT concentration already 6 h after Hx compared to the values before Hx. Twenty‐four hours after Hx we found the highest plasma concentrations. It was conspicuous that hepatic venous PCT concentrations were always higher than the arterial ones (significantly from the 6th hour after Hx). There was no correlation between the courses of ShvO2 and PCT rise. A significant correlation was verified between Hx duration and PCT concentration measured 24 h after Hx both in the hepatic venous and arterial blood.

Conclusions: The results of our investigation can be interpreted as evidence that liver (or the hepatosplanchnicus?) is a source of PCT. The mechanism of PCT induction cannot be clarified by our study: whether the induction of PCT was caused by an endotoxin translocation during the impeded splanchnic outflow or by the direct surgery‐induced lesion (hypoxia) of the liver remains unclear. However, the latter appears more probable because of the observed correlation between Hx duration and PCT concentration rise.
Losartan increases renal blood flow during isoflurane anesthesia in sheep
Authors: Ullman J. , Eriksson S. , Rundgren M.
Published: March 2003

Background: Inhaled anesthetics cause a transient reversible depression of renal function by direct renal effects or indirectly by changes in neurohumoral systems or cardiovascular performance. When the sympathetic nervous activity is decreased during anesthesia, other vasoactive systems like vasopressin (AVP) and particularly the renin angiotensin system (RAS) are of importance for blood pressure maintenance. Little is known about how the renal circulation is affected by angiotensin receptor blockade during isoflurane anesthesia.

Methods: The study was performed on isoflurane anesthetized sheep equipped with flow probes (placed around a femoral and a renal artery) and a pulmonary artery catheter. During stable conditions the sheep were given one or more of the following substances: isotonic saline (NaCl); losartan (LOS) 10 mg ·  kg−1; prazosin (PRAZ) 0.2 mg · kg−1 and a vasopressin V1‐receptor antagonist (AVP‐a) 10 μg · kg−1.

Results: LOS and AVP‐a did not affect mean arterial pressure (MAP), whereas PRAZ lowered MAP significantly (from 98±12 to 65±7 mmHg). Renal blood flow (RBF) increased after LOS treatment (148±34 to 222±33 ml · min−1). The other substances were without effect on RBF. Femoral blood flow remained unchanged after all treatments.

Conclusion: We conclude that the sympathoadrenal system is still the major determinant for blood pressure maintenance during isoflurane anesthesia in sheep. The apparently increased activity of the renin angiotensin system in this situation causes a reduction in renal blood flow, which is counteracted by angiotensin II AT1‐receptor blockade.
Rocuronium and anaphylaxis – a statistical challenge
Authors: Laake J. H. , Røttingen J.‐A.
Published: March 2003

Drug induced anaphylaxis is frequently attributed to the use of muscle relaxants during anaesthesia. Recently The Norwegian Medicines Agency recommended that rocuronium bromide (Esmeron) be withdrawn from routine practice due to frequent reports of anaphylaxis. Over a period of two and a half years approximately 150 000 patients received rocuronium as part of their anaesthesia. In this period the Norwegian drug authorities received 29 reports of anaphylaxis or anaphylactoid reactions in patients treated with rocuronium. This is in stark contrast to the situation in other Nordic countries where a total of only seven cases of anaphylaxis in approximately 800 000 patients treated with rocuronium had been recorded by December 2000. This situation highlights the many potential problems of the surveillance of adverse drug reactions: reporting bias may lead to an over‐estimate of the risk of one drug compared to another, and the possibility of under‐reporting of adverse events (due to a weak reporting culture) further limit the validity of such comparisons. The surveillance of adverse drug reactions also represents a statistical challenge. While adverse event reports may help us to estimate the anaphylaxis rate we need to appreciate the uncertainty of such estimates. Adverse reactions are rare, random, and mostly independent events, resulting from the successive exposure of patients to a low risk intervention. The frequency distribution of adverse events will therefore conform to that of a Poisson process. The resulting Poisson distribution may inform us about the variability of adverse event data. An understanding of these methodological problems and statistical challenges will allow anaesthesiologists to make informed decisions concerning the use of muscle relaxants and other drugs associated with severe adverse reactions.
Low‐dose dobutamine stress and left ventricular wall motion monitored with transesophageal echocardiography versus hemodynamic data derived from pulmonary artery catheterization in patients scheduled for CABG
Authors: Palmgren I. , Hultman J.
Published: March 2003

Background: The clinical acceptance of transesophageal echocardiography (TEE) as a monitoring technique for left ventricular function in open‐heart surgery is now widely recognized. This technique’s accurate imaging capabilities have been found to improve the information obtained by the pulmonary catheter (PAC) and thermodilution. TEE is also a less invasive technique than PAC. However, because it is costly, further comparisons between the techniques are worthwhile. This study compares hemodynamic data obtained with PAC and how these correspond to echocardiography data using TEE.

Methods: Twenty‐four anesthetized patients undergoing elective coronary artery bypass grafting (CABG) were studied. They were monitored with PAC and TEE. A low‐dose dobutamine protocol for viability was used with doses of 5 and 10 μg  ·  kg−1  ·  min−1. Endpoints for this stimulation included on‐line visual change in left ventricle wall motion (LVWM), increased arterial blood pressure more than 40 mmHg, a heart rate (HR) increase of more than 20%, or ST depression on ECG exceeding 0.2 mV. Visual assessment of LVWM using the transgastric short‐axis view was made off line by a blinded observer. Six segments were used and a wall motion score was made at each level of dobutamine stimulation.

Results & Conclusion:

Two patients reached the endpoint for elevated blood pressure with a dobutamine dose of 5 μg  ·  kg−1  ·  min−1, and twenty‐two patients were stimulated to 10 μg  ·  kg−1  ·  min−1. There were significant increases in cardiac output (CO), stroke volume (SV), systolic arterial pressure (SAP), mean arterial pressure (MAP), diastolic arterial pressure (DAP), pulmonary capillary wedge pressure (PCWP) and left ventricle stroke work index (LVSWI), but not in HR and systemic vascular resistance (SVR). Moreover, the LVWM increased significantly, but not fractional area change (FAC). The main finding, however, was the increase in SV with an accompanying improvement in LVWM, suggesting that visual assessment of improved wall motion could substitute PAC and thermodilution monitoring in clinical settings which demand a quick estimate of left ventricular performance.
Preconditioning − endogenous defence mechanisms of the heart
Authors: Sommerschild Hilchen T. , Kirkebøen Knut Arvid
Published: March 2003

The term ‘preconditioning’ refers to the paradoxical phenomenon that pretreatment with a potential noxious stress‐stimulus can increase cellular tolerance to subsequent noxious stress‐stimuli. This was first described in an experimental model in dogs in which short‐lasting periods of myocardial ischemia resulted in reduced infarction during a subsequent long‐lasting coronary artery occlusion. Similar observations have also been made in other species and in other organs. During the last few years, the term preconditioning has been expanded to include pretreatment with other physical stress‐stimuli or pharmacological agents that can increase cellular resistance to injury. The phenomenon probably represents a general adaptive response to cellular stress, but mechanisms involved are not fully clarified.

This review focuses on preconditioning in the heart. Firstly, we want to address the observation that activation of endogenous defence mechanisms can increase cellular tolerance to several potentially noxious stimuli. Based on results from experimental research, we will give an overview of intracellular mechanisms that is currently in focus. Secondly, we want to address the potential role of preconditioning in clinical practice. We will present results from studies in patients with coronary artery disease and discuss possible clinical implications. Results show that the phenomenon probably exists in the human myocardium. In the future, this might be exploited in patients with acute coronary syndromes, especially since advanced techniques are now available for acute revascularization. Additionally, identification of possible mechanisms involved may influence the choice of medical treatment in high‐risk patients with stable coronary artery disease. Preconditioning can also be exploited during elective surgical procedures. This should be of great interest, as the extent of elective surgery in patients at high‐risk for coronary events is increasing. In this respect it is important to note that opioid‐receptors are probably involved in preconditioning in humans. The last part of this review will address the possible relation between preconditioning and different anesthetic agents and sedatives.
Effect of hemodiafiltration and sepsis on chemotaxis of granulocytes and the release of IL‐8 and IL‐10
Authors: Toft P. , Brix‐Christensen V. , Bæch J. , Krog J. , Jørgensen H. S. , Tønnesen E. , Petersen T. K. , Dagnæs‐Hansen F.
Published: March 2003

Background: Extracorporeal circulation, such as cardiopulmonary bypass and hemodialysis, has been associated with an activation of the immune system. Continuous veno venous hemodiafiltration (CVVHD) is used in critically ill septic patients. During CVVHD, cytokines are excreted in ultrafiltrate. When the membranes, used in CVVHD, are incubated with leukocytes in vitro a slight production of cytokines is observed. Due to the underlying disease it is difficult to investigate the effect of CVVHD in septic patients. We therefore studied the separate effect of CVVHD on the chemotaxis of granulocytes, the proliferation of lymphocytes and the release of IL‐8 and IL‐10 in healthy pigs compared to an endotoxin and a control group.

Methods: Thirty‐one pigs were anesthetized and mechanically ventilated. CVVHD was performed in 10 pigs. Eleven pigs received an infusion of Escherichia coli endotoxin 30 µg/kg, and 10 pigs served as a control group. The chemotaxis of granulocytes was measured in an assay chamber, and the cytokines IL‐8 and IL‐10 with an enzyme‐linked immunosorbent assay. The adhesion molecules CD18 and CD62 on lymphocytes were measured using monoclonal antibodies, and the lymphocyte proliferation was measured without stimulation and in response to mitogens.

Results: CVVHD was accompanied by lymphocytopenia and increased spontaneous lymphoproliferative response, but no change in adhesion molecules on lymphocytes or cytokine levels in plasma, and no decrease in the chemotaxis of granulocytes. Following endotoxin we observed a pronounced lymphocytopenia and an increased secretion of IL‐8 and IL‐10, a decrease in the expression of CD18 on lymphocytes and in the stimulated lymphocyte proliferation and in the chemotaxis of granulocytes.

Conclusion: CVVHD does not, in contrast to endotoxin‐induced sepsis, influence chemotaxis of granulocytes, the production of IL‐8 and IL‐10 or the proliferation of lymphocytes.
Adrenocortical function and multiple organ failure in severe sepsis
Authors: Loisa P. , Rinne T. , Kaukinen S.
Published: March 2003

Background: Some patients with severe sepsis may have relative adrenocortical insufficiency, although not all studies confirm this finding. Corticosteroids play an important role in controlling excessive immune response, and they may reduce the severity of organ dysfunction in critical illness. In this prospective study, we investigated the incidence of adrenal insufficiency in severe sepsis and its relation to the development of multiple organ failure.

Methods: Forty‐one patients meeting the criteria for severe sepsis were studied. A short ACTH stimulation test was carried out within 24 h of the diagnosis of sepsis. Peak serum cortisol level < 680 nmol/L and a rise of less than 260 nmol/L were used as the criteria for relative adrenocortical insufficiency.

Results: Relative adrenocortical insufficiency was detected in six patients. Duration of the ICU stay (P = 0.002) and mechanical ventilation (P = 0.024) were significantly longer in patients with impaired adrenal function. In the survivors, SOFA scores were significantly higher in patients with impaired adrenal function. The plasma ACTH levels were normal in most of the patients with relative adrenal insufficiency, whereas most patients with normal adrenal function had extremely low plasma ACTH levels.

Conclusion: The ICU stay was longer and multiple organ failure more severe in patients with impaired adrenocortical function. There was a clear dissociation between ACTH and cortisol levels in AAR patients. This finding suggests that the integrity of the hypothalamic–pituitary–adrenal axis may be impaired in severe sepsis.
Albumin extravasation and tissue washout of hyaluronan after plasma volume expansion with crystalloid or hypooncotic colloid solutions
Authors: Berg S. , Golster M. , Lisander B.
Published: March 2003

Background: Intravascular volume expansion is followed by loss of fluid from the circulation. The extravasation of albumin in this readjustment is insufficiently known.

Methods: Twelve male volunteers participated, each in three separate sessions, in a controlled, randomised, open fashion. They received one of the following: albumin 40 g/L,(7.1 mL/kg, i.e. 500 mL per 70 kg); Ringer's acetate (21.4 mL/kg), or dextran 30 g/L (7.1 mL/kg). The fluids were infused during 30 min and the subjects were followed for 180 min. ECG, arterial oxygen saturation and non‐invasive arterial pressure were recorded. Haemoglobin, haematocrit, serum albumin and osmolality, plasma colloid osmotic pressure and hyaluronan concentration were determined in venous samples.

Results: The serum albumin concentration decreased (P < 0.05, anova) following Ringer's acetate or dextran, whereas serum osmolality was unchanged in all groups. The colloid osmotic pressure decreased (P < 0.05) after the Ringer solution. The blood volume increase was estimated from the decrease in haemoglobin concentration and did not differ between the three fluids. The cumulated extravasation of albumin was largest following albumin (10.4 ± 5.4 g, mean ± SD), less following dextran (5.6 ± 5.0 g) and negligible in the Ringer group (0.5 ± 10.0 g; P < 0.05 against albumin). However, the Ringer solution increased the plasma concentration of hyaluronan drastically.

Conclusions: Infusion of hypotonic colloidal solutions entails net loss of albumin from the vascular space. This is not the case after Ringer's acetate. Increased interstitial hydration from the latter fluid is followed by lymphatic wash out of hyaluronan.
Pharmacokinetics of a 24‐hour intravenous ketoprofen infusion in children
Authors: Kokki H. , Karvinen M. , Jekunen A.
Published: March 2003

Background: No pharmacokinetic data are available with respect to the plasma concentration of ketoprofen during intravenous infusion in children.

Methods: We present here the pharmacokinetics of ketoprofen after a 10‐min intravenous infusion of 1 mg/kg followed by a 24‐h infusion of 4 mg/kg in 18 children aged 7 months to 16 years. Venous blood samples were collected at 5 min, 1, 2, 4, 24 h following the loading dose, and then 1, 2 and 4 h after the end of the infusion. A validated HPLC method was used to measure plasma levels of ketoprofen.

Results: The steady state plasma concentration of ketoprofen was 2.0 µg/mL (range 1.3–2.7 µg/mL). The clearance of ketoprofen was 0.09 L·h−1·kg−1 (range 0.06–0.13 L·h−1·kg−1). The distribution volume was 0.16 L/kg (range 0.12–0.21 L/kg). The terminal half‐life was 1.3 h (range 0.8–1.7 h).

Conclusion: The pharmacokinetics of ketopofen in children is similar to that reported in adults. Our results indicate that ketoprofen is a feasible drug for continuous intravenous infusion in acute pain treatment in children.
Effect of metoclopramide on mivacurium‐induced neuromuscular block
Authors: Motamed C. , Kirov K. , Combes X. , Dhonneur G. , Duvaldestin P.
Published: March 2003

In order to investigate the effect of metoclopramide on the duration of action of mivacurium, 45 patients were randomized into three groups. Group M10 (n = 15) and M20 (n = 15) received 10 and 20 mg of metoclopramide i.v., respectively, and group S (n = 15) received saline 2 min before induction of anesthesia with fentanyl, thiopental and mivacurium. Plasma cholinesterase activity (pCHE) was measured before induction of anesthesia and 2 min after injection of metoclopramide and saline. Neuromuscular block was monitored by a force transducer using train of four nerve stimulation. Anesthesia was maintained with isoflurane and N2O. Time to recovery of a twitch height of 90% was significantly prolonged in group M10 and M20 (44 ± 15 and 57 ± 10 min) as compared to group S, 32 ± 9 min, P < 0.05). A slight but significant decrease in pCHE was observed in group M20. Because of the risk of prolonged duration of action of mivacurium, neuromuscular blockade should always be monitored whenever metoclopramide is given before injection of mivacurium.
Perioperative management of long QT syndrome in a child with congenital heart disease
Authors: Das S. N. , Kiran U. , Saxena N.
Published: March 2003

During cardiac catheterization, a 2½‐year‐old boy developed sudden cardiac arrest. The presence of a long QT interval in the electrocardiogram (ECG) along with ventricular arrhythmia and syncope at that moment enabled us to diagnose long QT syndrome (LQTS). Immediate defibrillation and beta‐blocker (metoprolol) therapy saved the life of the child. Cardiac catheterization was completed and the child was planned for Fontan operation. Beta‐blocker coverage, prevention of sympathetic stimulation and avoidance of agents which prolong the QT interval made anesthesia uneventful. There were episodes of ventricular fibrillation (VF) in the postoperative period. The child was managed with electrical defibrillation, metoprolol and magnesium.
Effect of sevoflurane on the mid‐latency auditory evoked potentials measured by a new fast extracting monitor
Authors: Alpiger S. , Helbo‐Hansen H. S. , Jensen E. W.
Published: March 2003

Background: Mid‐latency auditory evoked potentials (MLAEP) are widely suppressed during general anesthesia and may therefore be useful for assessment of the depth of anesthesia. However, interpretation of amplitudes and latencies in the AEP signal is time consuming. A new monitor (A‐line™) that quantifies the MLAEP into an index has therefore been developed. The present study aimed to assess the precision of a prototype of the new monitor and to test the hypothesis that the depth of anesthesia index shows a graded response with changing steady‐state end‐expiratory concentrations of sevoflurane.

Methods: We studied 10 ASA physical status I or II patients undergoing elective hysterectomy under combined epidural and general anesthesia by sevoflurane. Baseline auditory evoked potentials were recorded in the conscious patient immediately before induction of general anesthesia. Depth of anesthesia indices were recorded before anesthesia and at decreasing end‐expiratory steady‐state sevoflurane concentrations of 2.0%, 1.5%, 1.0% and 0.5%. All indices were recorded in duplicate 6 s apart. By use of an autoregressive model with exogenous input (ARX‐model), the monitor extracted the AEP within 6 s. The depth of anesthesia AEP index calculated in this way was defined as the A‐line ARX index (AAI).

Results: Approximately 95% of the differences between repeated recordings were 5 AAI‐units or less. A wide interindividual variation was observed at each observation point. AAI at 1%, 1.5% and 2% end‐expiratory concentration was significantly less than the baseline AAI obtained before induction of anesthesia (P < 0.001). AAI did not change significantly in the 1–2% concentration range.

Conclusion: The new monitor was precise. Attenuation of the A‐line ARX‐index (AAI) for mid‐latency auditory evoked potentials (MLAEP) during general anesthesia was profound. However, the monitor did not show a graded response with changing end‐expiratory steady‐state concentrations of sevoflurane.
Treatment of intracranial hypertension and aspects on lumbar dural puncture in severe bacterial meningitis
Authors: Grände P‐O. , Myhre E. B. , Nordström C‐H. , Schliamser S.
Published: March 2003

Background: Brain stem herniation due to raised intracranial pressure (ICP) is a common cause of mortality in severe bacterial meningitis, but continuous measurements of ICP and the effects of ICP‐reducing therapy in these patients have, to our knowledge, not been described.

Methods: During a four‐year period, an ICP‐monitoring device was implanted in patients admitted to our hospital with severe bacterial meningitis and suspected intracranial hypertension. ICP above 20 mmHg was treated using the Lund Concept, which includes antihypertensive therapy (β1‐antagonist,α2‐agonist), normalization of the plasma colloid osmotic pressure and the blood volume, and antistress therapy.

Results: ICP above 20 mmHg was found in all 12 patients studied. It was effectively reduced in all but two patients, who died. Both patients had a low cerebral perfusion pressure (<10 mmHg), dilated pupils at start of therapy and were beyond recovery. Radiological signs of brain swelling were present in only five patients. Seven patients recovered fully, while mild audiological impairment was observed in two and minor neurological sequelae in one patient. Eight patients showed signs suggesting imminent brain stem herniation before start of ICP‐reducing treatment, seven of whom had been subjected to diagnostic lumbar dural puncture shortly before development of the brain stem symptoms. These symptoms gradually regressed after initiation of therapy, and in one patient reversal of brain stem herniation was documented by MRI.

Conclusions: Severe bacterial meningitis can be associated with increased ICP, which can be reduced using the Lund Concept. The high survival rate, the low frequency of sequelae and the reversal of signs of imminent brain stem herniation in these high‐risk patients indicated beneficial effects of the intervention. The study confirms earlier observations that lumbar dural puncture is potentially hazardous in patients with intracranial hypertension, because it may trigger brain stem herniation. A normal CT brain scan does not rule out intracranial hypertension.
Intraoperative awareness: detected by the structured Brice interview?
Authors: Enlund M. , Hassan H. G.
Published: March 2003

Background:  Awareness is a rare complication in general anesthesia, but its consequences are stressful. Efforts must be undertaken to prevent, diagnose, and, if occurring, treat it. The incidence of awareness is higher following anesthesia involving the use of muscle relaxants. As a part of a quality assurance program at our short‐stay surgery all patients exposed to general anesthesia are routinely subjected to a Brice interview, which aims to evaluate our standard anesthetic technique regarding awareness.

Methods:  The Brice interview was used prospectively in 5216 patients given a propofol/opioid anesthetic for day‐case or short‐stay surgery. Neuromuscular blocks were used only for surgical needs, not routinely. All patients were interviewed on discharge from the recovery room. A second interview, according to Brice, was undertaken by telephone 3–7 days later in the case of a notable intraoperative event, or otherwise after postoperative patient complaints. All patients were also interviewed by telephone 1–2 days postoperatively.

Results:  None of the patient interviews indicated awareness. This was also the case in five non‐relaxed patients who had an incident of light anesthesia with eye opening and gross motor response without forewarning. Neuromuscular blockade was used in 7% of patients.

Discussion:  We were unable to detect intraoperative awareness. The anesthetic regimen, including minimal use of muscle relaxants, might be beneficial for awareness prevention. Alternatively, the diagnostic power, the timing of the Brice interview, or the number of interviews performed may be questioned.
Remifentanil infusion for cardiac catheterization in children with congenital heart disease
Authors: Foubert L. , Reyntjens K. , De Wolf D. , Suys B. , Moerman A. , Mortier E.
Published: March 2003

Background:  Cardiac catheterization of children with congenital heart disease is increasingly being performed under general anesthesia. Haemodynamic stability during anesthesia and fast and adequate recovery after the procedure is crucial in these patients. We performed a pilot study to evaluate hemodynamic stability when using remifentanil for anesthesia during cardiac catheterization. We also evaluated extubation times and recovery characteristics.

Methods:  In a randomized, prospective, double‐blind study 30 children (aged 1.5–20 months) received a continuous infusion of either 0.2 (group 0.2) or 0.3 µg/kg/min remifentanil (group 0.3) as part of a balanced anesthesia with 0.6 MAC sevoflurane. Heart rate, noninvasive arterial blood pressure, end tidal CO2 and pulse oxymetry were monitored throughout the procedure. Extubation times were noted, and recovery from anesthesia was evaluated using Aldrete scores.

Results:  Haemodynamic response to intubation was well blunted in both groups. No significant changes in hemodynamic variables were noted from induction of anesthesia until 10 min after intubation. From then on there was a decrease in HR and systolic arterial pressure, which remained significant throughout the procedure in both groups. Extubation times were similar in both groups: 7.3 min (2,1) in group 0.2 vs. 6.6 min (2,1) in group 0.3 (NS). The number of patients with an Aldrete score of nine or more was 14 (group 0.2) vs. 15 (group 0.3), 10 min after extubation (NS).

Conclusion:  Both dose regimens of remifentanil provided stable hemodynamic conditions during anesthesia for cardiac catheterization of children with congenital heart disease and allowed for rapid and adequate recovery.
Double‐blind comparison of the variability in spontaneous recovery of cisatracurium‐ and vecuronium‐induced neuromuscular block in adult and elderly patients
Authors: Pühringer F. K. , Heier T. , Dodgson M. , Erkola O. , Goonetilleke P. , Hofmockel R. , Gaetke M. R. , Mortensen C. R. , Upadhyaya B. , Eriksson L. I.
Published: March 2003

Background:  This study was designed to compare variability in the offset of two neuromuscular blocking agents with different elimination pathways.

Methods: The spontaneous recovery profiles of cisatracurium and vecuronium were compared in adult (18–64 years) and elderly (≥65 years) patients receiving N2O/O2/fentanyl/propofol anaesthesia. Patients were randomised to receive an initial bolus dose and maintenance doses of 3xED95, respectively, 0.6xED95 for cisatracurium (0.15 and 0.03 mg.kg−1) or 2xED95, respectively, and 0.4xED95 for vecuronium (0.1 and 0.02 mg.kg−1), as recommended in their prescribing information. Administration of the study drugs was double‐blinded, and neuromuscular transmission was monitored using mechanomyography of the evoked response of the adductor pollicis, following ulnar nerve stimulation.

Results: The clinically effective duration (minutes) of the initial bolus dose, defined as the mean time to 25% T1 recovery (±SD), for the adult and elderly patients was 53.5±9.8 and 57.3±11.5 for cisatracurium, respectively, and 34.1±9.0 and 47.5±14.4 for vecuronium, respectively. The duration of spontaneous sufficient recovery (SSR), defined as the mean (±SD) time interval in minutes from 25% T1 recovery to a T4:T1 ratio ≧0.8 after the last bolus dose, for the adult, respectively, elderly patients was 28.3±8.0 and 31.7±10.0 for cisatracurium and 38.5±13.2 and 60.3±26.1 for vecuronium.

Conclusion: Whereas both the clinically effective duration and the duration of SSR are comparable between the adult and the elderly patients receiving cisatracurium, they differ substantially between these two age groups for vecuronium. Furthermore, the variability in offset is significantly lower in patients receiving cisatracurium, especially in the elderly, which may be of particular clinical interest.
Oral clonidine premedication reduces the EC50 of propofol concentration for laryngeal mask airway insertion in male patients
Authors: Higuchi H. , Adachi Y. , Arimura S. , Nitahara K. , Satoh T.
Published: March 2003

Background:  Oral clonidine, an α2‐adrenergic receptor agonist, reduces the dose of propofol required for laryngeal mask airway (LMA) insertion. Target‐controlled infusion (TCI) is becoming increasingly popular for propofol infusion. There is no information, however, on the propofol blood concentrations required for LMA insertion and the effect of oral clonidine premedication on these values.

Methods: Propofol at target effect‐site concentrations from 4.0 to 12.0 µg/ml were randomly administered using TCI in three groups of healthy male patients (n=35 each) who were undergoing elective orthopedic surgery: control, 2.5 µg/kg clonidine, and 5.0 µg/kg clonidine groups. Nothing was administered to the control group. Clonidine(2.5 µg/kg or 5.0 µg/kg) was administered orally 90 min before arrival at the operating room in the clonidine groups. After equilibration between the blood‐ and effect‐site for 15 min, insertion of the LMA was attempted. The EC50 for LMA insertion (measured propofol serum concentration in equilibrium with the effect‐site at which 50% of patients do not respond to the insertion of the LMA) was determined by logistical regression.

Results: EC50±standard error values in the control, 2.5 µg/kg clonidine, and 5.0 µg/kg clonidine groups were 8.72±0.55, 7.76±0.60, and 5.84±0.58 µg/ml, respectively. The EC50 in the 5.0 µg/kg clonidine group was significantly lower than that in the control group (P < 0.01).

Conclusions: The propofol concentration required for LMA insertion in healthy male patients is reduced by premedication with 5.0 µg/kg oral clonidine.
Influence of surgery and endotoxin‐induced sepsis combined on natural killer cell activity, oxidative burst of granulocytes and antigen presentation capability of monocytes
Authors: Toft P. ,   Dagnæs‐Hansen, Tønnesen E. , Petersen M. S.
Published: March 2003

Background:  Cell mediated immunity is affected in the course of sepsis and following surgical stress. The natural killer (NK) cells, the granulocytes and the monocytes constitute the immediate unspecific cell mediated immunity. We therefore investigated the effect of surgery‐ and endotoxin‐induced sepsis on NK cells, granulocytes and monocytes in a two‐hit model.

Methods:  Three groups of 40 mice. Each group was divided into four groups of 10 mice. All the animals were anesthetized and subjected to either: laparotomy; treatment with Escherichia coli endotoxin i.p.; laparotomy followed 20 min later by endotoxin i.p.; or left untreated as a control group. In the first 40 mice the NK cell activity in the spleen and number of NK cells in the liver were measured, in the second the oxidative burst of granulocytes, and in the third the antigen presentation capacity of monocytes.

Results:  Endotoxin stimulated the NK cell activity and up‐regulated the antigen presentation capability on monocytes. In contrast, surgical stress reduced the NK cell activity, the number of NK cells and down‐regulated the antigen presentation capability on monocytes. After surgery, followed by administration of endotoxin, the oxidative burst of granulocytes was stimulated while antigen presentation capability on monocytes was down‐regulated. Endotoxin prevented or reverted the postoperative suppression of NK cell activity.

Conclusion:  Our two‐hit model shows that some cell types of the unspecific immune system exhibit an excessive inflammatory response (NK cells, granulocytes) while specific functions of other cell types (monocytes) are simultaneously diminished. This diversity makes a potential therapeutic immunomodulation very complex as some cell types would need to be down‐regulated while others need to be stimulated.
Comparison between intra‐articular bupivacaine with epinephrine and epinephrine alone on short‐term and long‐term pain after knee arthroscopic surgery under general anesthesia in day‐surgery patients
Authors: Toivonen J. , Pitko V.‐M. , Rosenberg P. H.
Published: March 2003

Background: Postarthroscopy analgesia has been provided with intra‐articular bupivacaine, but reported results are conflicting regarding efficacy and the duration of analgesia. The immediate and long‐term effects of intra‐articular bupivacaine with epinephrine after arthroscopic knee surgery were therefore studied in a day surgery setting.

Methods: 120 ASA I–II patients scheduled for arthroscopic knee surgery were given general anesthesia with spontaneous breathing via a laryngeal mask. In a randomized and blinded fashion half of them received, at the end of surgery, intra‐articularly 20 mL 0.5% bupivacaine with epinephrine (B + E‐group) and the other half 20 mL saline with epinephrine (S + E‐group). All patients received ketoprofen 100 mg i.v. during surgery and another 100 mg 2–3 h postoperatively. The patients were observed for about 4.5 h in the day surgery unit before discharge.

Results: The results showed that in comparison with the S + E‐group, significantly fewer patients in the B + E‐group needed analgesics (P < 0.0001) and the amount required was also significantly less postoperatively, before discharge (about 4.5 h postoperatively) (P < 0.0001). The latency to the need for the first postoperative analgesic was shorter in the S + E‐group patients (P < 0.0001). At home, during seven days after discharge, the need for analgesic (oral ketoprofen 100 mg) was greater in the B + E‐group (P < 0.05), especially only during the second postoperative day, but the visual analoque pain scale (VAPS) scores were low with no differences between the groups. No complication occurred.

Conclusion: It is concluded that a good postoperative pain control of intra‐articular bupivacaine with epinephrine was found only in the immediate postoperative period (i.e. before discharge) in a day‐surgery arthroscopic knee surgery patients.
Effect of delayed supine positioning after induction of spinal anaesthesia for caesarean section
Authors: Køhler F. , Sørensen J. F. , Helbo‐Hansen H. S.
Published: March 2003

Background:  The study tested the hypothesis that the incidence of hypotension during spinal anaesthesia for caesarean section is less in parturients who remain in the sitting position for 3 min compared with parturients who are placed in the modified supine position immediately after induction of spinal anesthesia.

Methods:  Spinal anaesthesia was induced with the woman in the sitting position using 2.8 ml hyperbaric bupivacaine 0.5% at the L3−4 or L2−3 interspace. Ninety‐eight patients scheduled for elective caesarean section under spinal anaesthesia were randomised to assume the supine position on an operating table tilted 10° to the left (modified supine position) immediately after spinal injection (group 0, n=52) or to remain in the sitting position for 3 min before they also assumed the modified supine position (group 3, n=46). Isotonic saline 2–300 ml was given intravenously over 15 min before spinal injection followed by 15 ml/kg over 15–20 min after induction of spinal anaesthesia. If the systolic blood pressure decreased to less than 70% of baseline or to less than 100 mmHg or if there was any complaint of nausea, ephedrine was given in 5 mg boluses intravenously every 2 min.

Results:  The blood pressure decreased significantly in both groups following spinal injection (P<0.001). Blood pressure variations over time differed significantly between the two groups (P<0.05). However, the incidence of maternal hypotension before delivery was similar in the two groups. The difference was caused by the time to the blood pressure nadir being significantly shorter in group 0 compared with group 3 (9.1±4.5 min vs. 11.7±3.7 min, P<0.01). Similar numbers of patients received rescue with ephedrine before delivery: 35 (67%) in group 0 vs. 26 (57%) in group 3 (NS). The mean total dose of ephedrine before delivery was 10.9 mg in group 0 vs. 9.2 mg in group 3 (NS). There were no differences in neonatal outcome between the two groups.

Conclusion:  At elective caesarean section, a 3‐min delay before supine positioning does not influence the incidence of maternal hypotension after induction of spinal anaesthesia in the sitting position with 2.8 ml of bupivacaine 0.5% with 8% dextrose.
Use of remifentanil for awake fiberoptic intubation in a morbidly obese patient with severe inflammation of the neck
Authors: Puchner W. , Obwegeser J. , Pühringer F. K.
Published: March 2003

Impending upper airway obstruction due to odontogenic facial and cervical spreading infection is a potential fatal situation that requires urgent treatment. In particular, securing the threatened airway is a priority and a precondition to the pressing need for surgery. The best approach to establish the difficult airway is awake fiberoptic intubation or scheduled tracheotomy under local anesthesia. We report a critical case of severe swelling of the neck in a morbidly obese patient with no alternative to awake fiberoptic intubation. The primary goals of optimal safety for the patient and appropriate intubating conditions for the anesthesiologist made us to consider a new method of patient medication.
Sevoflurane requirements during ambulatory surgery: a clinical study with and without AEP‐index guidance
Authors: Assareh H. , Anderson R. E. , Uusijärvi J. , Jakobsson J.
Published: March 2003

Background: Several monitors have been developed to measure anesthetic depth. The auditory evoked response uses an auditory signal to actively test the level of brain activity. The aim of the present study was to determine whether sevoflurane titration with A‐line auditory guidance from the evoked potential monitor would reduce gas consumption and improve recovery times.

Methods: Patients (n=60, aged 18–65 years) undergoing elective knee arthroscopy were randomized to titrate the main anesthetic sevoflurane with O2:N2O (1:2), either clinically (30 patients) or in combination with a target auditory evoked potential index of 30±5 (30 patients) using the A‐line monitor (version 1.4, Danmeter A/S; Odense, Denmark). Induction was supplemented with fentanyl, and randomized to 0.05, 0.10 and 0.15 mg immediately before propofol (10 in each group). Sevoflurane consumption and emergence times were the primary and secondary study end‐points.

Results: Guidance from the A‐line monitor did not reduce the sevoflurane consumption time or the emergence, regardless of the fentanyl dose. However, it did reduce the time from the recovery room to discharge eligibility (P<0.05). Sevoflurane consumption decreased inversely with the fentanyl dose (P<0.01), with no impact on emergence times.

Conclusion: The auditory evoked potential index provided by the A‐line monitor does not decrease sevoflurane consumption or emergence times for ambulatory knee arthroscopy.
Soda lime temperatures during low‐flow sevoflurane anaesthesia and differences in dead‐space
Authors: Luttropp H. H. , Johansson A.
Published: March 2003

Background: Sevoflurane degrades during low‐flow anaesthesia to compound A, and high carbon dioxide absorbent temperatures cause increased degradation. The purpose of this investigation was to determine if larger tidal volumes, without increasing alveolar ventilation, decrease the temperature in the carbon dioxide absorber during low‐ and minimal‐flow sevoflurane anaesthesia.

Methods: Prospective, randomized study, including 45 patients (ASA 1–2), scheduled for elective general or urology surgery. The patients were randomly assigned to one of three treatments. Patients in group 1 (NDS) received fresh gas flow of 1 litre/min without using additional dead‐space volumes. In group 2 (DS + 1.0), the patients received fresh gas flow of 1 litre/min using additional dead‐space volumes, placed between the Y‐piece and the HME, and patients in group 3 (DS + 0.5) received the same technique with a fresh gas flow of 0.5 litre/min. The soda lime temperatures, dead‐space volumes, end‐tidal carbon dioxide, sevoflurane concentrations, ventilation volumes and pressures, absorbent weight and ear temperatures were measured.

Results: The maximum temperature of the soda lime was 44.1 ± 1.1° C in the NDS group, 37.8 ± 0.8° C in the DS + 1.0 group and 38.5 ± 2.7° C in the DS + 0.5 group (P<0.0001). The dead‐space volume between the Y‐piece the tracheal tube was 164 ± 69 ml in the DS + 1.0 group and 196 ± 15 ml in the DS + 0.5 group (P<0.05). The ventilator pressure were higher in the DS groups compared with the NDS group (P<0.001). Soda lime weight increased in all groups. End‐tidal carbon dioxide, sevoflurane concentrations and ear temperatures were similar between the groups.

Conclusion: Increasing dead‐space volumes can reduce carbon dioxide absorber temperature during low‐ and minimal‐flow sevoflurane anaesthesia.