bluuebunny/crossref_metadata_2025 huggingface dataset:
3He‐MRI‐based vs. conventional determination of lung volumes in patients after unilateral lung transplantation: a new approach to regional spirometry
Authors: Markstaller K. , Kauczor H.‐U. , Puderbach M. , Mayer E. , Viallon M. , Gast K. , Weiler N. , Thelen M. , Eberle B.
Published: March 2003

Background: To use 3Helium (3He)‐MRI in patients with unilateral lung grafts to assess the contributions of graft and native lung to total ventilated lung volume, and second to compare conventional measurements of intrapulmonary gas volume (spirometry, body plethysmography) with image‐based volumetry of ventilated lung parenchyma visualized by hyperpolarized 3He‐MRI.

Methods: With Ethics Committee approval, five patients with single lung transplantation (SLTX) for idiopathic pulmonary fibrosis (IPF) underwent both conventional pulmonary function testing (PFT) and 3He‐MRI of the lung. Intrapulmonary gas volume (GV) during the inspiratory breathhold for 3He‐MRI was calculated from measured functional residual capacity (corrected for supine position) and inspired tidal volume. Image‐based global and regional lung volumetries (LV) were performed in three‐dimensionally reconstructed 3He‐MR images (corrected for the fraction of tissue and blood).

Results: Transplanted lungs were characterized by a homogeneous distribution of signal intensity, whereas the native lungs of the patients suffering from IPF displayed an inhomogeneous signal distribution pattern with numerous round or wedge‐shaped ventilation defects. Total ventilated lung volume determined by 3He‐MRI correlated well with PFT‐based measurements, but with a systematic overestimation of the 3He‐based lung volumetry of approximately 20%. Functioning lung grafts contributed 66±6% and their corresponding native IPF lungs 34±6% to total ventilated volume (P<0.05; mean±SD).

Conclusion: 3Helium‐MRI of the lung offers a novel approach to regional determination of ventilated lung volume, including its blood and tissue compartments. The advantage of this technique over computed tomography or ventilation scintigraphy is the lack of radiation exposure, and hence its repeatability. Follow up of SLTX patients with this new technique may allow the monitoring of functional and structural developments of grafted lungs with better sensitivity and specificity than PFT.
Pulmonary endothelial dysfunction after cardiopulmonary bypass in neonatal pigs
Authors: Glavind‐Kristensen M. , Brix‐Christensen V. , Toennesen E. , Ravn H. B. , Forman A. , Sorensen K. , Hjortdal V. E.
Published: March 2003

Background: In neonatal pigs cardiopulmonary bypass (CPB) is associated with endothelial dysfunction in isolated large pulmonary arteries. It is, however, of great importance if this functional change extends to the small pulmonary resistance arteries, which are the key regulators of pulmonary flow and pressure. The aim of this study was to assess changes in pulmonary microvascular function after CPB using a clinically relevant pediatric procedure.

Methods: From three groups of neonatal pigs (CPB‐, sham‐ and control group) pulmonary resistance arteries and systemic resistance arteries (from skeletal muscle) were isolated and mounted as ring preparations in wire myographs. Vessel diameters were less than 500 µm. Concentration‐response curves were constructed for norepinephrine (NA), vasopressin (Vp), and the thromboxane A2‐analog U46619, while the endothelium‐dependent and ‐independent vasodilator functions were assessed as responses to acetylcholine and nitric oxide (NO).

Results: Maximum pulmonary vasodilator response to acetylcholine was attenuated after CPB compared with sham‐operated and control animals (P=0.04). NO‐induced relaxation, and contractile responses to NA, Vp, and U46619 were not influenced by CPB. In systemic arteries no changes in contractile or relaxant responses were seen after CPB.

Conclusion: CPB seems to induce pulmonary endothelial dysfunction in pulmonary but not peripheral resistance arteries in neonatal piglets.
Lipid solubility‐ and concentration‐dependent attenuation of in vitro natural killer cell cytotoxicity by local anesthetics
Authors: Krog J. , Hokland M. , Ahlburg P. , Parner E. , Tønnesen E.
Published: March 2003

Background: Natural killer (NK) cells constitute an essential component of the innate immune system in the defence against infected and malignant cells. In this study the in vitro effect on NK cell activity of three different local anesthetics with different lipid solubility was investigated.

Methods: Venous blood from seven healthy volunteers was incubated with three amide local anesthetics with three different concentrations of lipid solubility: lidocaine 0.50, 1.00 and 2.00 mg/ml, ropivacaine 0.375, 0.75 and 1.50 mg/ml, and bupivacaine 0.25, 0.50 and 1.00 mg/ml. After 1 h of incubation, mononuclear cells were isolated and cryopreserved until tested for NK cell cytotoxicity in a 4‐h 51Cr‐release assay against K‐562 target cells. Natural killer cell cytotoxicity of mononuclear cells incubated with isotonic saline was used as the control.

Results: A significant suppression in NK cell cytotoxicity was demonstrated for all three local anesthetic agents when the NK cell cytotoxicity was compared with the cytotoxicity estimated after incubation with the isotonic saline (P<0.004). Moreover a significant lipid solubility‐dependent effect (P=0.0001) as well as an overall concentration‐dependent effect (P<0.0001) on the NK cell cytotoxicity was found.

Conclusion: The results of the present in vitro study suggest a negative association between the estimated NK cell cytotoxicity and the lipid solubility as well as the concentrations of the three local anesthetic agents tested.
Skin conductance correlates with perioperative stress
Authors: Storm H. , Myre K. , Rostrup M. , Stokland O. , Lien M. D. , Ræder J. C.
Published: March 2003

Background: Skin conductance (SC) as a measure of emotional state or arousal may be a tool for monitoring surgical stress in anaesthesia. When an outgoing sympathetic nervous burst occurs to the skin, the palmar and plantar sweat glands are filled up, and the SC increases before the sweat is removed and the SC decreases. This creates a SC fluctuation. The purpose of this study was to measure SC during laparoscopic cholecystectomy with propofol and remifentanil anesthaesia and to evaluate whether number and amplitude of SC fluctuations correlate with perioperative stress monitoring.

Methods: Eleven patients were studied nine times before, during and after anaesthesia. SC was compared to changes in stress measures such as blood pressure, heart rate, norepinephrine and epinephrine levels. SC was also compared to changes in Bispectral index (BIS).

Results: The blood pressure, epinephrine levels and norepinephrine levels were positively correlated with both the number (P < 0.001) and amplitude (P < 0.01) of the SC fluctuations. Moreover, the BIS was positively correlated with the number (P < 0.001) and amplitude (P < 0.001) of the SC fluctuations. Furthermore, during tracheal intubation, the mean levels of the number of SC fluctuations from the 11 patients had the same stress response as measured in changes of the mean levels of norepinephrine. The mean BIS did not show any stress response during tracheal intubation.

Conclusion: Number of SC fluctuations may be a useful method for monitoring the perioperative stress.
Quality assurance in anaesthetic practice: comparison between two methods in detecting complications
Authors: Niskanen M. , Tuovinen T. , Purhonen S. , Vauhkonen S. , Hendolin H.
Published: March 2003

Background: Reliable identification and documentation of complications is an essential part of a well‐functioning quality system (QS) in anaesthetic practice. The criteria for the complications have to be appropriate. The QS of Kuopio University Hospital fulfils the ISO 9002 standard. The validity of the recordings in the QS was ascertained by comparing the routine recordings with external assessment.

Methods: Three types of complications were predefined: minor, severe and those specific for regional anaesthesia. A total of 1006 anaesthetic charts, including general, regional and intravenous anaesthesia, were randomly selected and retrospectively screened by an external assessor. The retrospective assessment of complications was compared to the recordings in the data management system for operative procedures (DMS) as a part of routine quality assurance. Cohen's kappa statistics was used to indicate agreement between two raters.

Results: Both methods identified complications in 115 procedures (11.4%). The methods, however, did not identify complications in same procedures. There was a fairly close agreement (P < 0.001) between the methods in detecting all (Cohen's kappa 0.72), minor (0.67) and severe (0.66) complications and those specific for regional anaesthesia (0.78). Fifty‐eight complications were detected either by retrospective assessment or routine reporting, i.e. the two raters disagreed in 58 complications. Thirteen severe complications recorded in the DMS could not be retrospectively identified. The agreement did not depend on ASA class, the urgency or the length of procedures or on the type of anaesthesia.

Conclusions: The agreement between external assessment and routine reporting was fairly good, however, there were still some relatively large differences. The selection and definitions of complications need to be reassessed.
Impact factor bias and proposed adjustments for its determination
Authors: Fassoulaki A. , Papilas K. , Paraskeva A. , Patris K.
Published: March 2003

Background: The impact factor (IF), a qualitative parameter used to evaluate scientific journals, has several flaws. The aim of the study was to evaluate two of its important constraints, journal self‐citation and scientific field, and to investigate the potential for improvement.

Methods: We studied the five or six highest impact journals from each of seven medical fields: anesthesiology, dermatology, genetics and heredity, immunology, general and internal medicine, ophthalmology and surgery. To correct for journal self‐citation, we divided the number of 1998 citations of papers published in 1996 and 1997, minus the self‐citations, by the number of papers published in the same period. For inter‐field normalization we divided the IF by the mean of the IFs of the upper quartile for the same category of medical field (IF/fcat).

Results: For the 36 journals, there was a negative correlation between IF and self‐cited and self‐citing rates (rs = −0.765, P < 0.001 and rs = −0.479, P < 0.003, respectively). Self‐cited rate is the ratio of a journal's self‐citations to the number of times it is cited by all journals including itself. Self‐citing rate relates a journal's self‐citations to the total references it makes. The IF/fcat for the 36 journals are positively correlated with their conventional IF (rs = 0.91, P < 0.001).

Conclusion: Correcting the IF of the 36 journals for self‐citation did not significantly change journal rankings. The adjusted IF/fcat to normalize for the scientific field was positively correlated with the conventional IF.
Central pontine myelinolysis: sequele of hyponatremia during transcervical resection of endometrium
Authors: Shah V. R. , Parikh G. P. , Bhosale G.
Published: March 2003

Transcervical resection of endometrium is an alternative to hysterectomy for women with menorrhagia. The procedure involves the use of cutting loop diathermy to resect the endometrium while the uterine cavity is irrigated with 1.5% glycine which can absorb consequent fluid and electrolyte shifts. Severe hyponatremia leading to central pontine myelinolysis is an extremely rare complication of this procedure. We report a case of a young female undergoing transcervical resection of endometrium for menorrhagia, who developed central pontine myelinolysis but made a complete recovery after three months.
How to study postoperative nausea and vomiting
Authors: Apfel C. C. , Roewer N. , Korttila K.
Published: March 2003

Anesthesiological journals are flooded by innumerable studies of postoperative nausea and vomiting (PONV). Nevertheless, PONV remains a continuing problem with an average incidence of 20–30%. This paper should provide essential information for the design, conduct, and presentation of these studies. It should also increase comparability among future studies and help clinicians in assessing and reading the literature on PONV.

First, future studies should address new and relevant questions instead of repeatedly investigating prophylactically given antiemetics whose main results are predictable (e.g. already proven by meta‐analysis). Second, group comparability should be based on well‐proven risk factors and a simplified risk score for predicting PONV. Endless listings of doubtful risk factors should be avoided. Third, a realistic sample size estimation should be performed, i.e. in most cases at least 100 patients per group are necessary. Fourth, nausea, vomiting and rescue medication should be recorded and reported separately with the corresponding incidences (and number of patients with these separate symptoms), and the main end‐point should be PONV. The entire observation period should cover 24 h. Additional reporting of the early (0–2 h) and delayed (2–24 h) postoperative period is desirable and should consider single and cumulative incidences. Lastly, interpretation of results should take into account the study hypothesis, sources of potential bias or imprecision, and the difficulties associated with multiplicity of analysis and outcomes.
Guidelines for the practice of anesthesia in Norway
Authors: Gisvold S. E. , Ræder J. , Jyssum T. , Andersen L. , Arnesen C. , Kvale L. , Mellin Olsen J.
Published: March 2003

Since the first version saw the light of day in 1991 the Guidelines have occupied a central position in the Norwegian practice of anesthesia.

This document comprises part of the quality management documents held in the departments of anesthesia in Norwegian hospitals.

If departments of anesthesia are unable to adhere to certain specific points in the Guidelines, it is recommended that this should be documented in writing.

It has been stated by central governmental bodies and patients' insurance organizations that the Guidelines will be an important factor in medico legal cases, although it is not an obligatory legal document for hospital owners.

It is our objective that the document will form the foundation for quality assurance work in the departments of anesthesia in Norway.

The purpose of this document is to ensure a satisfactory standard for the practice of anesthesia in Norway. ‘The Guidelines for the Practice of Anesthesia in Norway’ (the Guidelines) is a series of recommended guidelines.

The practice of anesthesia in this context includes general anesthesia, regional anesthesia, controlled sedation, postoperative monitoring, and other observations where anesthesia personnel are required.

The Guidelines apply to all doctors, nurses, and other personnel undertaking the delegated practice of anesthesia.

Deviations from the Guidelines should be explained and documented in every case. The Guidelines should be adhered to in medical emergencies as far as possible.

The Guidelines must not be allowed to prevent the execution of immediate and lifesaving measures.

The Guidelines should be revised at regular intervals so that it is up‐to‐date with current legislation and medical and technological developments and practice.
On what are our end‐of‐life decisions based?
Authors: Pettilä V. , Ala‐Kokko T. , Varpula T. , Laurila J. , Hovilehto S. ,   the Finnish SSAI candidates
Published: March 2003

Background: The incidence of withholding and withdrawing life support from the critically ill has increased in recent years. The aim of this study was to assess the degree of consistency between the weight assigned by intensivists to different determinants and their relation to end‐of‐life decisions, and to evaluate the current concepts in withholding or withdrawing intensive care in Nordic countries.

Methods: Forty‐one intensivists from Nordic countries completed a questionnaire sent by e‐mail: consistency between contributing factors and the decisions regarding 10 actual cases was evaluated by logistic regression analysis and by the classification (leave‐one‐out) method. Concepts in management after the withdrawal decision were also analyzed.

Results: The median (range) number of withdrawals per physician was four (range 0–10) out of 10 cases. No single factor was an independent covariant of all decisions made. The classification method revealed that approximately 70% only of decisions could be predicted correctly. Different actions taken after a decision to withdraw intensive care varied from 9.8% (discontinuing ventilator therapy) to 97.6% (informing relatives).

Conclusions: No generally accepted grounds for end‐of‐life decisions could be detected among Nordic intensivists. In addition, the current concept of management after decision to withdraw therapy varies markedly. This study has implications in further assessment of the individual decision‐making process and the uniformity of actions after withdrawal decisions.
Plasma exchange in severe postpartum HELLP syndrome
Authors: Förster J. G. , Peltonen S. , Kaaja R. , Lampinen K. , Pettilä V.
Published: March 2003

We present a case of extremely severe postpartum HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome, associated with activation of coagulation, massive recurrent intra‐abdominal bleeding requiring two laparotomies, renal failure, and central nervous system symptoms. This case underlines the complexity of pregnancy‐related thrombotic microangiopathies regarding their differential diagnosis, multiple organ dysfunction, as well as management. Systemic endothelial cell injury plays a central role in the pathogenesis of thrombotic microangiopathies. Treatment of HELLP syndrome usually consists of administration of antihypertensive therapy and magnesium sulfate. No consensus exists regarding the use of plasma exchange or corticosteroids. Plasma exchange was a major part of the treatment regime in our patient. Early plasma exchange may be considered as an adjuvant therapy in severe and progressive postpartum HELLP syndrome.
Accuracy of point‐of‐care‐testing (POCT) for determining hemoglobin concentrations
Authors: Gehring H. , Hornberger C. , Dibbelt L. , Roth‐Isigkeit A. , Gerlach K. , Schumacher J. , Schmucker P.
Published: March 2003

Background: While point‐of‐care testing (POCT) is being used increasingly as a basis for deciding on perioperative erythrocyte transfusion, no valid standards currently exist concerning the accuracy of Hb concentration measurements. For clinical employment, however, the confidence limits (±2 SD) of these measurements should lie close to 5 g/l. The aim of the present study was to evaluate the accuracy and precision of point‐of‐care testing for blood hemoglobin concentration (cHb in g/l) measurements in critically ill patients.

Methods: Fifty blood samples from 50 postoperative patients requiring intensive care treatment were withdrawn from a cannula in the radial artery into a 2‐ml heparinized syringe (containing wet sodium heparinate in the conus), in a 2‐ml Monovette with 50 IE lithium heparinate, and into a 2.7‐ml cuvette with 1.6 mg potassium EDTA/ml blood. The POCT battery consisted of two blood gas analyzers (ABLTM 625 and 725, Radiometer, Copenhagen), the HemoCue® system (Mallinckrodt Medical, Germany), and an automated hematology analyzer (M‐2000®, Sysmex, Germany). The cyanmethemoglobin method served as the reference ‘gold standard’ procedure. The blood gas analyzer and HemoCue® systems were tested using dry and wet heparinized blood samples.

Results: Hemoglobin concentrations of the reference measurements ranged from 73.9 to 159.4 g/l. The automated hematology analyzer method did reveal a small but systematic deviation for higher cHb values. For the blood gas analyzer and HemoCue® system procedures there was no systematic deviation of bias for either the first measurement or the averaged data. Bland & Altman analysis revealed a larger scattering for the wet heparinized samples.

Conclusions: The above‐stated requirement for POCT systems, i.e. that the confidence limits should lie close to 5 g/l cHb, held true for the dry heparinized samples of the blood gas analyzer (1st measurement and mean of 2), the HemoCue® system (mean of 3) and the automated hematology analyzer.
Prostaglandin E1 at clinically relevant concentrations inhibits aggregation of platelets under synergic interaction with endothelial cells
Authors: Koga T. , Az‐Ma T. , Yuge O.
Published: March 2003

Background: The inhibitory effect of prostaglandin E1 (PGE1) on platelet aggregation is considered an important characteristic of this agent. However, the concentration of PGE1 to inhibit aggregation in vitro is higher than those of clinical use (1 ng/ml). To clarify whether PGE1 at clinically relevant concentrations inhibits aggregation under synergic action with endothelial cell‐derived factors (nitric oxide and prostacyclin), we evaluated the minimum effective concentration of PGE1 to enhance the anti‐aggregating activity of endothelial cells.

Methods: Inhibitory effects of PGE1 and/or the incubation buffer from cultured porcine aortic endothelial (PAE) cells on human platelet aggregation induced by 2 µg/ml collagen were examined by turbidimetry.

Results:  PGE1 concentration‐dependently (>3 ng/ml) inhibited aggregation: the incubation buffer from PAE cells stimulated by bradykinin also inhibited aggregation. Bradykinin concentration‐dependently increased the anti‐aggregating activity of the PAE incubation buffer. The half‐maximum effective concentration of bradykinin to inhibit aggregation (95.4±22.3 nM) was significantly decreased to 10.3±2.5 nM by 0.1 ng/ml PGE1 and to 0.9±0.5 nM by 1 ng/ml PGE1, respectively. These indicated that PGE1 (=0.1 ng/ml) inhibits aggregation through synergism with endothelial cells. The synergic effect of PGE1 and the anti‐aggregating activity of the PAE cells preincubated with 10 µM indomethacin for 30 min was more potent than that of these cells preincubated with 1 mM NG‐nitro‐L‐arginine methyl ester. This suggested that the interaction of PGE1 with endothelial cell‐derived nitric oxide is more powerful than that with endothelial cell‐derived prostacyclin.

Conclusion: Prostaglandin E1 (=0.1 ng/ml) inhibited platelet aggregation under synergic interaction with endothelial cells.
Classification for coding procedures in the intensive care unit
Authors: Flaatten H. , Bonde J. , Ruokonen E. , Winsø O.
Published: March 2003

Background: There is no commonly accepted coding system for non‐operative procedures in general, including intensive care unit (ICU) procedures. In order to create a classification of codes for ICU procedures, a system developed at the University Hospital of Bergen was evaluated in four Nordic countries.

Methods: Classification codes were constructed using seven main groups of related procedures that were given a letter from A to G. Within each group major procedures were given a number from 00 to 99, with the possibility of up to 10 subclassifications within each procedure. A simple questionnaire regarding the use of coding general ICU procedures and some specific procedures was sent to 171 ICUs in Sweden, Finland, Denmark, and Norway. They were also asked to give their comments on the new classification coding system, which was attached.

Results: One hundred and fifty‐four questionnaires were returned (response rate 90%). Some or most of the ICU procedures were registered in the ICUs (82.2%). However 38% did not use any coding system and 24% used a specific internal system. The new classification coding system was well received, and was given a mean value of 7.5 using a VAS scale from 0 to 10 (best). Most ICUs would consider using this system if introduced at a national level.

Conclusion: Most Nordic ICUs do register some or most of the procedures performed. Such procedures are however, registered in very different ways, using several different systems, and are often home‐made. The new classification system of ICU procedures was well rated.
Acetylcholine receptor density in human cricopharyngeal muscle and pharyngeal constrictor muscle
Authors: Sundman E. , Yost C. S. , Margolin G. , Kuylenstierna R. , Ekberg O. , Eriksson L. I.
Published: March 2003

Background: Upper esophageal sphincter resting tone is reduced during partial neuromuscular block, whereas contraction of the pharyngeal constrictor muscle is only slightly affected. We hypothesized that this difference may arise from differential nicotinic acetylcholine receptor (nAChR) density, the density supposedly being lower in the more sensitive cricopharyngeal muscle than in the resistant pharyngeal constrictor muscle. The aim of this study was to determine the density of nAChR in the main component of the upper esophageal sphincter, the cricopharyngeal muscle, and in the pharyngeal constrictor muscle.

Method: After approval by the institutional ethics committee and informed consent, muscle specimens were obtained from five patients undergoing surgery with laryngectomy for malignancies of the larynx or thyroid gland. None had received radiation therapy to the affected area. The nAChR from these tissue specimens were solubilized and incubated with 125I‐α‐bungarotoxin. The quantity of radioligand‐receptor complex was measured by radioactive decay in a liquid scintillation counter. The receptor density was expressed as femtomoles per milligram of protein (fmol/mg protein).

Results: The nAChR density was determined to 6.8 (3.5) fmol/mg protein (mean (SD)) in the cricopharyngeal muscle and 5.6 (2.1) fmol/mg protein in the pharyngeal constrictor muscle (P = 0.22). Although we could not find any difference in mean nAChR density, contrary to our hypothesis, the density in four of the five patients was higher in the cricopharyngeal muscle than in the pharyngeal constrictor muscle.

Conclusion: Our results indicate that the density of nicotinic acetylcholine receptors is similar in the cricopharyngeal muscle and in the pharyngeal constrictor muscle. Nicotinic acetylcholine receptor density, as determined by 125I‐α‐bungarotoxin assay, cannot explain the difference in response to neuromuscular blocking drugs between the investigated muscles.
Design evaluation of commonly used rigid and levering laryngoscope blades
Authors: Yardeni I. Z. , Gefen A. , Smolyarenko V. , Zeidel A. , Beilin B.
Published: March 2003

Background: The shape of a laryngoscope blade affects the exposition of the larynx. This study evaluates and compares some rigid and levering blade designs based on previous investigative X‐ray laryngoscopic studies.

Methods: Five rigid laryngoscope blades (Miller #3, Standard Macintosh #3, Classical Macintosh #4 and English‐Macintosh #3 and #4) and two levering laryngoscope blades (McCoy in neutral and maximally elevated positions and Flexiblade in three basic positions: straight, neutral, and maximally curved) were evaluated. This study assesses two parameters derived from the depth of insertion: the eye line deviation from the ideal straight view line to the vocal cords, and the space occupied by the blade behind the mandible, which affects the contact of the blade tip with the base of the tongue.

Results: The best results on larynx exposition were produced by the English‐Macintosh #4 at all insertion depths between 5 and 14 cm. It surpassed the Classical Macintosh #4 and both the English and Standard Macintosh #3. Although the Miller and the Flexiblade in a straight position afford a nearly ideal view line, both blades reduce the space reserved for the tongue behind the mandible. The McCoy with its tip maximally elevated provides limited view, while activation of the Flexiblade provides various ranges of larynx exposition.

Conclusion: The difference in shape and design of Macintosh blades affects their performance. The distal portion of a large‐sized curved blade is more effective than the full length of a shorter blade. The #4 English Macintosh is a better choice for routine clinical use. The Flexiblade performs as a multiblade device and can therefore be used for both routine and difficult intubations.
Target‐controlled infusion of propofol induction with or without plasma concentration constraint in high‐risk adult patients undergoing cardiac surgery
Authors: Macquaire V. , Cantraine F. , Schmartz D. , Coussaert E. , Barvais L.
Published: March 2003

Background: Calculated plasma (Cp) and calculated effect site concentrations (Ce) of propofol associated with loss of consciousness (LOC) have been studied in young healthy patients. The aim of the study was to evaluate the calculated propofol concentrations required to induce LOC in ASA III adult patients undergoing cardiac surgery using a smooth target controlled infusion of propofol.

Methods: After informed consent, 44 patients were premedicated with 0.5 mg alprazolam orally. Propofol TCI using the pharmacokinetic set of Marsh et al. incorporated in the Diprifusor (ThalfKeo of 2.6 min) was used. Propofol Ce was progressively increased by 0.5 µg/ml until LOC was obtained. The constraint on the maximum gradient between Cp and Ce was either 1 µg/ml in group 1 or not limited in group 2. Hemodynamic variations were assessed.

Results: Mean preoperative left ventricular ejection fractions were 44 ± 15.4% and 56 ± 11.4% in groups 1 and 2, respectively (P < 0.01). At LOC, mean Cp was 1.9 µg/ml in both groups but mean Ce was 1.08 ± 0.31 and 1.43 ± 0.42 µg/ml in groups 1 and 2, respectively (P < 0.01). The mean induction time was 12.8 ± 7.1 min in group 1 and 8.5 ± 2.7 min in group 2 (P < 0.05). No episode of hypotension has been observed in either group.

Conclusion: In ASA III patients undergoing cardiac surgery, smooth propofol TCI induction, using the pharmacokinetic set of Marsh et al. incorporated in the Diprifusor, is associated with LOC at a low mean calculated plasma concentration of 1.9 µg/ml and good hemodynamic stability.
Sevoflurane low‐flow anaesthesia: best strategy to reduce Compound A concentration
Authors: Di Filippo A. , Marini F. , Pacenti M. , Dugheri S. , Focardi L. , Novelli G. P.
Published: March 2003

Background: To define the best strategy to reduce Compound A production in Sevoflurane low‐flow anaesthesia by experiments in vitro and in vivo of different absorbers and different anaesthesia machines.

Methods: In vitro
Compound A has been measured at 45°C
in vitro
following Sevoflurane interactions with potassium hydroxide, sodium hydroxide, soda lime, Dragersorb 800 Plus and Amsorb, a new absorber that does not contain sodium or potassium hydroxide.
In vivo Compound A concentration in the anaesthesia circuit (inspiratory branch) has been measured using an indirect sampling method through absorber vials (SKC) with active coal granules, during low flows (500 ml/min) general anaesthesia using soda lime, Dragersorb 800 Plus or Amsorb as absorber. Compound A was also measured during low flows (500 ml/min) general anaesthesia using as carbon dioxide absorber soda lime with different anaesthesia machines.

Results: In vitro
at 45°C Compound A concentration with soda lime and Dragersorb 800 Plus was about 10 times higher than with Amsorb.
In vivo the Compound A concentrations in the inspiratory branch of the circuit were lower in the group with Amsorb.

Conclusion:  The Compound A production is minimal with Amsorb as carbon dioxide absorber.
Effect of pretreatment with ketorolac on propofol injection pain
Authors: Huang Y. W. , Buerkle H. , Lee T. H. , Lu C. Y. , Lin C. R. , Lin S. H. , Chou A. K. , Muhammad R. , Yang L. C.
Published: March 2003

Background:  Pain on injection is still a major problem with propofol. We performed this study to compare different doses of intravenous (i.v.) ketorolac with and without venous occlusion and its effect on the incidence and the severity of the pain after propofol injection.

Methods: We conducted a prospective, randomized and double‐blind study of 180 patients (20–60 years of age.) scheduled to undergo elective surgery. Six groups of patients were generated: group A received normal saline (NS) 2 ml i.v.; groups B, C, D received ketorolac 10 mg in 2 ml NS with venous occlusion (VO) and a subsequent propofol injection at either 30, 60 or 120 s; groups E and F received ketorolac 15 mg and 30 mg in 2 ml NS and propofol was injected after 60 s. The pain perception was assessed during injection of propofol in all patients.

Result:  The incidence of propofol‐associated injection pain was for A: 46.7%; B: 43.4%; C: 23.3%; D:16.7%; E: 20%, and F: 10%. The incidence of pain following propofol injection was reduced by i.v. ketorolac 10 mg with venous occlusion for 120 s. Furthermore, i.v. ketorolac 15 mg and 30 mg but not 10 mg following propofol injection after 60 s without venous occlusion revealed significant pain reduction when compared to saline group. There was no difference in venous sequelae at 7 days postoperatively between the groups.

Conclusion: Our results suggested that pretreatment with i.v. 15 and 30 mg ketorolac reduces pain following propofol injection. Moreover, pretreatment with i.v. ketorolac 10 mg with venous occlusion for 120 s achieves the same pain relief effect.
A comparative study on the analgesic effect of tramadol, tramadol plus magnesium, and tramadol plus ketamine for postoperative pain management after major abdominal surgery
Authors: ÜNlügenç H. , Gündüz M. , ÖZalevli M. , Akman H.
Published: March 2003

Background: We tested whether, after major abdominal surgery, the addition of magnesium or ketamine to tramadol for intravenous (IV) patient‐controlled analgesia (PCA) improved analgesia and lowered pain scores, compared to a PCA containing only tramadol.

Methods: Sixty‐six patients were allocated randomly to receive a PCA with tramadol alone (T), tramadol plus magnesium (TM) or tramadol plus ketamin (TK), in a double‐blind randomized study. Postoperative analgesia was started when the verbal rating scale (VRS) score was 2 or more. Following a loading dose of the study solution (which contained 1 mg/kg tramadol), a background infusion of 0.4 mg/kg/h was started. Patients were allowed to use bolus doses of 0.2 mg/kg every 20 min without a time limit. Discomfort, sedation, pain scores, total and bolus PCA tramadol consumption, and side‐effects, were recorded for up to 24 h after the start of PCA.

Results: Pain and discomfort scores were lower (P < 0.01) in groups TM and TK at 15, 30, 60 and 120 min than in group T. The addition of magnesium or ketamine significantly reduced the consumption of tramadol at 6, 12 and 24 h (P < 0.01). The incidence of nausea did not differ between the groups.

Conclusion: Adding magnesium or ketamine to tramadol improved analgesia and patient comfort and decreased the amount of tramadol required for postoperative pain management after major abdominal surgery.
Interscalene brachial plexus block is superior to subacromial bursa block after arthroscopic shoulder surgery
Authors: Laurila P. A. , Löppönen A. , Kangas‐Saarela T. , Flinkkilä T. , Salomäki T. E.
Published: March 2003

Background: Arthroscopic shoulder surgery is often associated with severe postoperative pain. The results concerning subacromial bursa blockade (SUB) as a method of pain relief have been contradictory. We hypothesized that a SUB and interscalene brachial plexus block (ISB) would similarly reduce early postoperative pain and the need for oxycodone as compared to placebo (PLA).

Methods: Forty‐five patients scheduled for arthroscopic shoulder surgery were enrolled in this randomised, prospective study. The ISB and SUB blockades were performed with 15 ml of ropivacaine (5 mg/ml). In the PLA group, 15 ml of 0.9% saline was injected into the subacromial bursa. All patients received general anaesthesia.

Results: The mean intravenously patient‐controlled delivered oxycodone consumption during the first 6 h was significantly lower in the ISB group (6 mg) than in the SUB group (24.1 mg; P=0.001) or in the PLA group (27 mg; P<0.001). No significant differences were detected between the SUB and PLA groups (P=0.791). The postoperative pain scores during the first 4 h at rest and during the first 6 h on movement were significantly lower in the ISB group than in the SUB and PLA groups.

Conclusion: After arthroscopic shoulder surgery SUB has a minor effect only on postoperative analgesia, whereas an ISB with low‐dose ropivacaine effectively relieves early postoperative pain and reduces the need for opioids.
Thoracic sympatholysis with epidural blockade assessed by quantitative measurement of cutaneous blood flow
Authors: Nygård E. , Sejrsen P. , Kofoed K. F.
Published: March 2003

Background: Quantifying sympathetic activity is difficult. Direct measurement is possible and superior to indirect techniques, but nerves to internal organs are not accessible in humans. Recently, we validated a quantitative technique for measurement of cutaneous blood flow using heat as an indicator. The aim of the study was to investigate whether sympatholysis during thoracic epidural blockade (TEA) may be documented by changes in regional cutaneous blood flow. A secondary aim was to assess whether, during TEA, local heating itself enhances regional blood flow.

Methods: Six patients scheduled for elective coronary artery bypass grafting (CABG) were studied. An epidural catheter was inserted at the T2–3 interspace. Measurements were performed with an electrode, which can measure the local temperature of the skin. The probe is covered with a thermostatically controlled cap to avoid a thermic gradient to air. As a result of the cap, a change in temperature of the central disc depends almost solely on the blood flow in the underlying tissue. Regional cutaneous blood flow rates were measured before and after epidural anesthesia with and without local heating.

Results and comments: All patients had a sensory blockade covering at least T1–5. Cutaneous blood flow increased in all six patients after blockade (13.6 ml/min/100 g, range 10.6–14.6 vs. 18.4 ml/min/100 g, range 13.9–24.5; P<0.05). Local heating did not further enhance blood flow.

Conclusion: High TEA is associated with a uniform increase in thoracic cutaneous blood flow, and is suggestive of regional sympatholysis. Quantitative measurements of skin blood flow appear promising for documenting regional sympatholysis during TEA.
Post‐dural puncture syndrome in an elderly patient with remote history of previous post‐dural puncture syndrome
Authors: Kuczkowski K. M. , Benumof J. L.
Published: March 2003

History of previous post‐dural puncture syndrome (PDPS) is a strong risk factor for another PDPS when spinal anesthesia is readministered to these patients. We herein report a case to show that this general rule may still apply even after the passage of 50 years.
Ventilator treatment in the Nordic countries.  A multicenter survey
Authors: Kárason S. , Antonsen K. , Åneman A. , GROUP The SSAI ICU‐II
Published: March 2003

Background: A 1‐day point prevalence study was performed in the Nordic countries to identify ventilator‐treatment strategies in the region.

Material and methods: On 30 May 30 2001 all mechanically ventilated patients in 27 intensive care units (ICUs) were registered via the internet. The results are shown as medians (25th, 75th percentile).

Results:  One hundred and eight patients were included (69% male) with new simplified acute physiology score (SAPS) 48 (37,57) and 4.5 d (2,11) of ventilator treatment. The most frequent indication for ventilator treatment was acute respiratory failure (73%). Airway management was by endotracheal tube (64%), tracheostomy (32%) and facial mask (4%). Pressure regulated ventilator modes were used in 86% of the patients and spontaneous triggering was allowed in 75%. The tidal volume was 7 ml/kg (6,9), peak inspiratory pressure 22 cmH2O (18,26) and positive end‐expiratory pressure (PEEP) 6 cmH2O (6,9). FiO2 was 40% (35,50), SaO2 97% (95–98), PaO2 11 kPa (10,13), PaCO2 5.4 kPa (4.7,6.3), pH 7.43 (7.38,7.47) and BE 2.0 mmol/l (− 0.5,5). The PaO2/FiO2 ratio was 220 mmHg (166,283). The peak inspiratory pressure (r=0.37), mean airway pressure (r=0.36), PEEP (r=0.33), tidal volume (r=0.22) and SAPS score (r=0.19) were identified as independent variables in relation to the PaO2/FiO2 ratio.

Conclusion: The vast majority of patients were ventilated with pressure‐regulated modes. Tidal volume was well below what has been considered conventional in recent large trials. Correlations between the parameters of gas exchange, respiratory mechanics, ventilator settings and physiological status of the patients was poor. It appears that blood gas values are the main tool used to steer ventilator treatment. These results may help to design future interventional studies of ventilator treatment.
The prognostic value of global haemostatic tests in the intensive care unit setting
Authors: Nilsson G. , Astermark J. , Lethagen S. , Vernersson E. , Berntorp E.
Published: March 2003

Background: Global haemostatic tests are often abnormal in critically ill patients, secondary to activation or consumption of coagulation factors or inhibitors. Methods for analysing plasma levels of these factors are, however, not widely available, and the predictive value of global tests is not known. We examined the clinical applicability to predict the outcome of the global haemostatic tests used at most hospitals.

Methods: Blood was collected from patients within 6 h of admission to an intensive care unit (ICU) and tested regarding platelet count, International Normalized Ratio (INR), and activated partial thromboplastin time (APTT). Ninety‐two patients with platelet counts <100 × 109 l−1, INR > 1.36 and/or APTT >45 s were included in a study group, and an additional 92 patients with a comparable age and sex distribution, but not fulfilling these laboratory criteria, constituted a control group. The following data were recorded for each patient: number of days in the ICU and hospital; alive or deceased when released from the ICU and hospital; survival at 30 days and 180 days.

Results: Survival upon discharge from the ICU and hospital was significantly reduced in the study group. This was especially pronounced in patients with medical disorders, whereas the survival rate was slightly higher in surgery patients. Expressing the survival predicting ability of the screening tests as odds ratios for all patients (study and control groups together) indicated that prolonged APTT in particular foretold a lower survival rate at studied time‐points after admission to the ICU.

Conclusions: The global haemostatic tests INR and APTT can predict survival in critically ill patients, and prolonged APTT in particular seems to be associated with a negative prognosis.
Induction and mechanism of apoptotic cell death by propofol in HL‐60 cells
Authors: Tsuchiya M. , Asada A. , Arita K. , Utsumi T. , Yoshida T. , Sato E. F. , Utsumi K. , Inoue M.
Published: March 2003

Background: Apoptosis (programmed cell death) occurs in various physiological and pathological conditions, exhibits a characteristic mechanism of intracellular sequential reaction and may be involved in determining clinical outcome. The antioxidant activity of propofol (2,6‐diisopropylphenol) together with the stimulating effect of protein kinase C suggests that propofol might have the potential to modulate apoptosis. Thus, it is of both clinical interest and biomedical importance to investigate and clarify the effect and mechanism of propofol upon the intracellular reactions underlying apoptotic cell death.

Methods: The effect of propofol on apoptosis was investigated using cultured human promyelocytic leukemia HL‐60 cells. This well‐characterized cell line is useful for the study of apoptosis because the various biochemical steps occurring during apoptosis have been well documented.

Results: Treatment of HL‐60 cells with propofol resulted in growth inhibition with the formation of apoptotic bodies in a concentration‐dependent manner. DNA fragmentation and ladder formation was also observed in a concentration‐dependent manner. Propofol treatment resulted in activation of caspase‐3, ‐6, ‐8 and ‐9, thereby suggesting that cell surface death receptor activation of the caspase cascade mediates propofol‐induced apoptosis with consequent formation of the cleaved product of Bid (a pro‐apoptotic Bcl‐2 family member protein) and activation of the mitochondrial pathway with cytosolic release of cytochrome c.

Conclusion: Propofol may induce apoptosis, which is dependent on the mechanism that activates both the cell surface death receptor pathway and the mitochondrial pathway.
High frequency oscillatory ventilation in adult patients with acute respiratory distress syndrome – a retrospective study
Authors: Andersen F. A. , Guttormsen A. B. , Flaatten H. K.
Published: March 2003

Background: At present there are limited data about the effects of high frequency oscillatory ventilation (HFOV) in adult patients with acute respiratory distress syndrome (ARDS). This study evaluates efficacy of HFOV in such patients.

Methods:  Sixteen ARDS patients, mean age 38.2 years (range 18–76), that underwent HFOV between 1997 and 2001 were enrolled in the study and evaluated in retrospect. FIo2, arterial blood gases, mean airway pressure (mean Paw), blood pressure, heart rate and central venous pressure were recorded by 4, 8, 12, 24, 48 and 72 h of HFOV and compared to conventional mechanical ventilation (CMV) at baseline (4 h prior to HFOV).

Results:  On admission to the ICU, mean Simplified Acute Physiology score (SAPS II) was 40.3 (SD 12.6). Main causes of ARDS were pneumonia (9/16) and burn injuries (4/16). At baseline the patients had severe ARDS as noted by a mean lung injury score (LIS) of 3.2 (SD 0.3) and Pao2/FIo2 ratio 12.2 (SD 3.2) kPa. Within 4 h of HFOV, Pao2/FIo2 increased to 17.3 (SD 5.9) kPa (P = 0.016). Throughout HFOV, Pao2/FIo2 was significantly higher than at baseline. There were no significant changes in haemodynamic parameters. Ending HFOV after 6.6 (SD 3.2) days, survivors (n = 11) significantly reduced their Sequential Organ Failure Assessment Score (SOFA) compared to baseline. Survival at 3 months was 68.8%.

Conclusion:  HFOV effectively improves oxygenation without haemodynamic compromise. During HFOV, the SOFA score may predict outcome.
Compensatory fluid administration for preoperative dehydration – does it improve outcome?
Authors: Holte K. , Kehlet H.
Published: March 2003

Background: Preoperative fasting may lead to a fluid deficit of about 1 litre, which may contribute to perioperative discomfort and morbidity. We therefore examined the association between perioperatively administered fluids aiming to correct dehydration and clinical outcome.

Methods: Review of randomized, controlled, clinical trials evaluating clinical outcome, in which fluid versus no fluid was administered pre‐ or intraoperatively, attempting to correct preoperative fluid deficits. Data were obtained from a Medline search (1966–2001), and references cited in original papers. Seventeen trials met the inclusion criteria.

Results: Based on the amount of fluid administered, we divided the studies into two groups. In nine studies, fluid administration was <1 litre, and in eight studies ≥1 litre of fluid was administered. Administration of low‐dose fluid reduced preoperative thirst, but the limited data do not allow conclusions on postoperative outcome such as nausea, vomiting, headache and pain. Administration of ≥1 litre fluid generally reduced postoperative drowsiness and dizziness, while the effects on postoperative nausea, vomiting and thirst has not been clarified.

Conclusion: Fluid administration to compensate preoperative dehydration improves symptoms related to dehydration. Based on the available data, administration of about 1 litre fluid pre‐ or intraoperatively in patients having fasted for minor surgical procedures seems rational.