bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of left ventricular systolic function during elevated external cardiac pressures: an examination of measured transmural left ventricular pressure during pressure–volume analysis
Authors: Haney M. F. , Johansson G. , Häggmark S. , Biber B.
Published: March 2003

Background: Variations or disturbances in intrathoracic and extracardiac pressures (ECP) occur in critically ill and anaesthetised patients. There are uncertainties concerning the analysis of left ventricular pressure–volume relationship (LVPVR) and the calculation of systolic function parameters when conducted without reference to transmural left ventricular pressure (LVPtm) in the setting of elevated ECP.

Methods: In 7 anaesthetised adult pigs, we measured LVPVR using conductance volumetry and tip manometry along with measurement of pericardial and other intrathoracic pressures. Experimental pericardial infusion and pleural insufflation were performed. Transient controlled preload reductions were accomplished using balloon occlusion of the inferior vena cava. Preload recruitable stroke work (PRSW) was calculated using both intracavitary left ventricular pressure (LVPic) and LVPtm, and differences were tested for using a paired t‐test.

Results: The pericardial and pleural interventions produced significant elevations in ECP. No difference in PRSW calculated using LVPic and LVPtm was detected.

Conclusion: These results suggest that LVPtm need not be measured and included in LVPVR analysis of systolic function when there is significant external cardiac pressure. To be able to employ LVPVR analysis of systolic function without reference to LVPtm is important for simplified application in the clinical setting, particularly when elevated extracardiac pressures are suspected, or have been therapeutically induced, as with continuous positive pressure ventilation.
Effects of positive end‐expiratory pressure on intestinal circulation during graded mesenteric artery occlusion
Authors: Lehtipalo S. , Biber B. , Fröjse R. , Arnerlöv C. , Johansson G. , Winsö O.
Published: March 2003

Background: Reduced gut perfusion is associated with multiple organ failure. Positive end‐expiratory pressure (PEEP) reduces cardiac output (CO) and portal blood flow, and might be detrimental in a situation of already compromised intestinal circulation. The aim of this study was to investigate regional circulatory and metabolic effects of PEEP during graded regional hypoperfusion.

Methods: In 12 barbiturate‐anesthetized pigs, we measured systemic and regional blood flows (superior mesenteric arterial, QSMA and portal venous, QPORT), jejunal mucosal perfusion (LDF), tissue oxygenation (PO2TISSUE) and metabolic parameters at PEEP (0, 4, 8 and 12 cm H2O) in a randomized order. Measurements were performed at unrestricted intestinal perfusion pressures (IPP) and at IPP levels of 50 and 30 mmHg.

Results: During unrestricted IPP, PEEP decreased MAP, CO, QSMA and QPORT, while systemic, and preportal (RPORT) vascular resistances and jejunal mucosal perfusion were not significantly changed. Preportal tissue oxygen delivery and PO2TISSUE decreased, while preportal tissue oxygen uptake was unaltered. During restricted IPP, PEEP produced the same pattern of hemodynamic alterations as when IPP was not restricted. QPORT and QSMA were lowered by the reductions in IPP, and QPORT was further reduced during PEEP. At an IPP of 30 mmHg, this reduction in QPORT decreased preportal tissue oxygen uptake. Consequently, intestinal ischemia, as indicated by increased net lactate production, occurred. Simultaneously, jejunal mucosal perfusion and PO2TISSUE declined.

Conclusion: At IPP levels below 50 mmHg, even moderate levels of PEEP impaired local blood flow enough to cause intestinal ischemia. Our data underscore the importance of considering regional circulatory adaptations during PEEP ventilation.
High concentrations of adrenergic antagonists prolong sciatic nerve blockade by tetrodotoxin
Authors: Kohane D. S. , Lu N. T. , Crosa G. A. , Kuang Y. , Berde C. B.
Published: March 2003

Background: Millimolar‐range concentrations of some adrenergic antagonists have been shown to have local anesthetic‐like properties, and to stimulate GTPase activity in vitro. In this report, we investigate whether these agents can potentiate the effect of tetrodotoxin (TTX) and bupivacaine, a conventional local anesthetic, and whether GTPase activation plays a role.

Methods: Rats received sciatic nerve blockade with tetrodotoxin or bupivacaine co‐injected with adrenergic antagonists and/or agonists, or pertussis toxin. Thermal nociceptive blockade was quantified with modified hotplate testing.

Results: Nerve block from TTX alone lasted 153 (99–223) min (median and 25th and 75th percentiles). Co‐injection with 20 mM phentolamine, propranolol, and yohimbine prolonged TTX block to 856 (765–862), 486 (444–510), and 465 (413–495) min respectively (P<0.005 in all cases, compared to TTX alone). Micromolar concentrations of adrenergic antagonists (which inhibited the prolongation of TTX block by epinephrine) did not prolong TTX block. Injection of adrenergic antagonists alone did not produce specific nerve block. They did not prolong TTX block when injected at a remote subcutaneous site. Prolongation of TTX block by phentolamine was not inhibited by co‐injection with pertussis toxin. Adrenergic antagonists did not prolong bupivacaine block.

Conclusions: High concentrations of adrenergic antagonists markedly prolonged TTX block, but not bupivacaine block. This locally mediated action does not appear to be adrenergic‐receptor‐specific, or mediated by GTPase activation.
Pulmonary hemorrhage in association with negative pressure edema in an intubated patient
Authors: Sow Nam Y. , Garewal D.
Published: March 2003

Negative pressure pulmonary edema due to upper airway obstruction following extubation is a well‐recognized problem. However, frank pulmonary hemorrhage as a manifestation of upper airway obstruction is uncommon. We report a case of significant pulmonary hemorrhage and negative pressure pulmonary edema in an intubated patient. Bronchoscopy showed a collection of blood in the right lower lobe of the lungs, suggesting a localized source of bleeding. There have been two previously reported cases of pulmonary hemorrhage after upper airway obstruction. One suggested that the bleeding was due to damage to the pulmonary capillaries, the other that it was due to disruption of the bronchial vessels. We feel that in our case there was some indication that the pulmonary bleeding was a result of bronchial vessel damage. A number of factors might have been involved in its development, including negative pulmonary pressure, recent respiratory tract infection, and positive airways pressure (due to coughing).
Spinal anesthesia for a patient with type I sialidosis undergoing abdominal surgery
Authors: Tran Q. H. D. , Kaufman I. , Schricker T.
Published: March 2003

Type I and II sialidosis are autosomal recessively inherited glycoprotein storage disorders. Until now, there has been no published reports of patients with these conditions requiring anesthesia. We present the case of a 31‐year‐old male afflicted with type I sialidosis who underwent a surgical jejunostomy. Regional (spinal) anesthesia was carried out uneventfully. We discuss the anesthetic challenges posed by patients with type I and II sialidosis. Airway assessment and management is particularly crucial.
Treatment with paracetamol in infants
Authors: Arana A. , Morton N. S. , Hansen T. G.
Published: March 2003

Background: Paracetamol (N‐acetyl‐p‐amino‐phenol) or acetaminophen has become the most widely used analgesic and antipyretic in children. However, there is a wide discrepancy between the extent to which paracetamol is used and the limited available pharmacological data in small infants. The purpose of this article is to present a review of the current literature regarding the use of paracetamol in neonates and infants with a particular emphasis on pharmacological issues.

Methods: A MEDLINE search (up to March 2000) was conducted to identify relevant English‐language publications using paracetamol, children, infants and neonates as search terms. Additional studies were identified from bibliographies of the reviewed literature.

Results: Pharmacological studies on paracetamol in infants are few. Most studies have focused on the administration of one single paracetamol dose, and the problem of cumulative toxicity with repeated dosing has not been addressed. Plasma paracetamol concentration should be 10–20 mg ml−1 to achieve antipyretic and analgesic effects. The bioavailability of the different formulations and routes of administration vary with age. Rectal absorption is slower and more erratic than the oral; however, in the very young, rectal bioavailability is higher than in older patients. Volume of distribution seems to be age‐independent, whereas clearance is reduced in neonates and particularly in preterm babies. Neonates and infants are capable of forming the reactive intermediate metabolite that causes hepatocellular damage, particularly after multiple doses. They have an immature glucuronide conjugation system, but the rate constant for the sulphation metabolic pathway is larger than in older children, and this is the most important route of metabolism.

Conclusions: The pharmacokinetics and pharmacodynamics of paracetamol differ substantially in neonates and infants from those in older children and adults; hence, dosing should be adjusted accordingly.
A single‐injection, multi‐segmental paravertebral block – extension of somatosensory and sympathetic block in volunteers (Note)
Authors: Saito T. , Den S. , Cheema S. P. S. , Tanuma K. , Carney E. , Carlsson C. , Richardson J.
Published: March 2003

Background: It is our experience that a deposition of an anesthetic solution in the ventral area of the paravertebral space near the parietal pleura and the sympathetic trunk produces extended unilateral block. Because sympathetic block effects in this extended paravertebral block are not reported yet, we undertook this singly blinded, controlled study on the sympathetic change in volunteers.

Methods: A total of 22 ml 1% lidocaine was injected at the T11 level into the ventral area of the right‐sided paravertebral space in 16 volunteers. The distribution of analgesia, heart rate, blood pressure and body temperature (measured by 12 skin sensors) was monitored. On a later occasion the volunteers underwent a control injection of saline.

Results: Unilateral analgesia (with no contralateral element) was induced in every subject injected with lidocaine, contrasted with no block induction with saline. Loss of pin‐prick sensation was observed within 10 min after injection and involved a mean of 12 (range 8–13) dermatomes. A sympathetic block was indicated by cutaneous temperature increase within at least 6 dermatomes. Increase of arterial blood pressure was obtained in all volunteers with no change in pulse rate. No side effects or complications occurred. Epidural spread of the local anesthetic was unlikely because of the absence of contralateral cutaneous analgesia and temperature increase.

Conclusion: One‐sided extended analgesia (sensory loss) follows the paravertebral injection of lidocaine. A large ipsilateral sympathetic block is observed without change in pulse rate and with no hypotension. These are all characteristics of an optimal regional block.
Measuring patient satisfaction with anaesthesia: perioperative questionnaire versus standardised face‐to‐face interview
Authors: Bauer M. , Böhrer H. , Aichele G. , Bach A. , Martin E.
Published: March 2003

Background: Patient satisfaction represents an essential part of quality management. Measuring the degree of patient satisfaction can be achieved with a variety of tools such as postoperative visits and patient questionnaires. The primary aim of this study was to quantify the degree of patient satisfaction with anaesthesia. A secondary aim was to compare the questionnaire technique with standardised face‐to‐face interviewing.

Methods: The authors prospectively studied 700 patients on the second postoperative day. Patients were randomised and allocated to complete either a written questionnaire or to answer the same questions during a standardised face‐to‐face interview. The questionnaire was subdivided into a set of questions on anaesthesia‐related discomfort and another set on satisfaction with anaesthesia care in general. The questions on discomfort were assessed on a 3‐point scale, and those on patient satisfaction on a 4‐point scale.

Results: Response rate was 84% (589 of 700 patients). Internal consistency, as measured by Cronbach’s α, was 0.84. When evaluating the questions on anaesthesia‐related discomfort, the most frequent sensations were “drowsiness” (>75%), “pain at the surgical site” (>55%), and “thirst” (>50%). The data on patient satisfaction showed a high degree of satisfaction (>90%). The responses to questions on anaesthesia‐related discomfort revealed only minor differences between the questionnaire and the face‐to‐face interview. The questions on satisfaction with anaesthesia, however, were answered consistently in a more critical manner during the interview (P<0.0001).

Conclusions: The standardised interview may be more suited to determine patient satisfaction than a questionnaire. Quality improvements are possible for emergence from anaesthesia, postoperative pain therapy, and the treatment of postoperative nausea and vomiting.
The influence of halothane, isoflurane and sevoflurane on rocuronium infusion in children
Authors: Woloszczuk‐Gebicka B. , Lapczynski T. , Wierzejski W.
Published: March 2003

Background: Rocuronium is a non‐depolarizing neuromuscular blocking agent with intermediate duration of action and without significant cumulative properties, suitable for continuous infusion. This study was designed to determine the infusion requirements in children under nitrous oxide and fentanyl, halothane, isoflurane or sevoflurane anaesthesia.

Methods: Forty children, 3–11 years old, ASA physical status group I or II were studied. They were randomly allocated to receive fentanyl‐nitrous oxide, 1 MAC halothane‐nitrous oxide, 1 MAC isoflurane‐nitrous oxide or 1 MAC sevoflurane‐nitrous oxide anaesthesia. Rocuronium, 0.6 mg−1 was used to facilitate endotracheal intubation. Electromyographic response of adductor pollicis to train‐of‐four (TOF) stimulation, 2 Hz for 2 s, applied to the ulnar nerve at 10‐s intervals was recorded using Relaxograph (Datex, Helsinki, Finland). Once the first twitch response (T1) returned to 5%, muscle relaxation was maintained by continuous infusion of rocuronium, adjusted automatically in a closed‐loop system to maintain a stable 90–99% T1 depression. The block was considered stable if it changed by no more than 2% over a 10‐min observation period.

Results: Halothane, isoflurane and sevoflurane groups had lower infusion requirements than the fentanyl‐nitrous oxide group (P<0.00075). Rocuronium requirement (mean ± SD) at one hour from the commencement of anaesthesia was 16.7±2.3, 13.6±3.7, 13.1±5.1 and 8.4±1.6 μg · kg−1 · min−1 for children receiving fentanyl‐nitrous oxide, halothane, isoflurane and sevoflurane anaesthesia, respectively.

Conclusions: The rocuronium infusion rate required to maintain stable 90–99% T1 depression was reduced by approximately 20% with halothane and isoflurane anaesthesia, and by 50% with sevoflurane anaesthesia when compared to fentanyl‐nitrous oxide anaesthesia. Significant patient‐to‐patient variability of infusion rate makes monitoring of neuromuscular transmission necessary.
Aminoguanidine does not influence tissue extravasation of albumin in endotoxaemic rats
Authors: Metcalf K. , Lisander B.
Published: March 2003

Background: It is generally maintained that protein and fluid are lost from the circulation under septic conditions. The role played by an increased production of nitric oxide, by the inducible nitric oxide synthase (iNOS), in this process is unclear.

Methods: Chloralose anaesthetised male Wistar rats received E. coli lipopolysaccharide (LPS), 3 mg kg−1 i.v., and were studied for 5 h. Mean arterial pressure (MAP) and heart rate (HR) were monitored and haematocrit (Hct) was determined intermittently. Tissue plasma volume and tissue clearances of radiolabelled albumin over the last 2 h of the experiment were determined by a double‐isotope method. In 8 rats, 2 h after LPS, aminoguanidine, an iNOS selective blocker, was given i.v. at a dose of 5 mg kg−1. This was followed by a continuous infusion for the duration of the experiment; altogether 20 mg kg−1 was administered. In the control group (n=8), a corresponding volume of saline was infused.

Results: Aminoguanidine did not significantly influence Hct, MAP and HR, as evidenced by inter‐group comparisons (Mann‐Whitney test). Tissue plasma clearances of albumin and tissue plasma volume were similar in both groups.

Conclusion: Aminoguanidine at 20 mg kg−1 did not reverse the haemodynamic changes induced by LPS. Neither did the drug affect the tissue plasma clearance of albumin or the tissue plasma volume.
Effects of isoflurane on nitric oxide metabolism and oxidant status of guinea pig myocardium
Authors: Durak İ. , Kavutcu M. , Kaçmaz M. , Avci A. , Horasanli E. , Dikmen B. , Çimen M. Y. B. , Öztürk H. S.
Published: March 2003

Background: Volatile anesthetics (VAs) have been shown to enhance myocardial recovery during reperfusion, the mechanism of which has not been clarified yet. It has been supposed that this effect of VAs may appear through antioxidative mechanisms.

Methods: Thirty guinea pigs were used in the study. There were three groups with 10 animals in each: I – control, II – isoflurane+oxygen and III – oxygen. Isoflurane (2.0% v/v) and oxygen (100%) mixture was given to the animals via a face mask in the isoflurane+oxygen group at the rate of 2 l per min for 30 min a day for three consecutive days. In the oxygen group, oxygen alone (100%) was given under the same conditions as in the isoflurane+oxygen group. At the end of the experiments, the animals were killed and their hearts were removed. In the heart tissues, nitric oxide synthase (NOS) activity, nitric oxide (NO) pool (NO•+NO2−) and malondialdehyde (MDA) levels were measured.

Results: NOS activity was found to be higher and the NO pool lower in the isoflurane+oxygen group compared with those of control and oxygen groups. In the oxygen group, MDA level was found to be higher compared to the other groups. There was, however, no significant difference between MDA levels of the control and isoflurane+oxygen groups.

Conclusion: Our results suggest that isoflurane prevents peroxidation reactions in heart tissue, possibly by scavenging toxic oxygen radicals produced under hyperoxygenation conditions as occurs with general anesthesia.
The Combitube® for failed intubation – Instructions for use
Authors: Enlund M. , Miregård M. , Wennmalm K.
Published: March 2003

The Combitube® is easy to use, but it might be years between occasions for use, and most likely the situation is stressful. Then, normal routines might be forgotten. We illustrate that the Combitube® instructions would be improved by including a recommendation of cuff pressure monitoring.
Descending aortic blood flow and cardiac output: A clinical and experimental study of continuous oesophageal echo‐Doppler flowmetry
Authors: Odenstedt H. , Åneman A. , Oi Y. , Svensson M. , Stenqvist O. , Lundin S.
Published: March 2003

Background: Several studies have demonstrated that perioperative optimisation of oxygen delivery and haemodynamics can reduce mortality and morbidity for high‐risk surgical patients. To optimise cardiac output, reliable, continuous and “less invasive” methods for measuring cardiac output are urgently needed.

Methods: Eight landrace pigs were studied during experimental repeated cardiac tamponade and 14 patients during liver transplantation. Aortic blood flow was measured by using transoesophageal echo‐Doppler technique. A total of 91 paired measurements of aortic blood flow and cardiac output with different techniques were performed in the pigs and 124 paired measurements in the patients.

Results: Transoesophageal echo‐Doppler did provide continuous real‐time monitoring of the rapid and dramatic haemodynamic changes occurring during cardiac tamponade and during liver transplantation, while only intermittent information was obtained from the bolus thermodilution technique. Changes in haemodynamics were more difficult to detect with the “continual” cardiac output thermodilution technique. Changes in aortic blood flow closely followed changes in cardiac output determined by the bolus thermodilution technique both in pigs (r=0.89) and in patients (r=0.80). In patients, aortic blood flow constituted about 70% of cardiac output determined by the bolus thermodilution technique.

Conclusions: A combined echo‐Doppler technique can be valuable for continuous monitoring of haemodynamic changes in the perioperative setting, and changes in aortic blood flow agree well with corresponding changes in cardiac output intermittently obtained by thermodilution cardiac output measurements. With the combined echo‐Doppler technique a proper position of the Doppler beam is greatly facilitated by the M‐mode echo visualisation of the aortic wall and aortic cross‐sectional area is continuously measured.
THIS ARTICLE HAS BEEN RETRACTED: Point‐of‐care (POC) testing of lactate in the intensive care patient
Authors: Boldt J. , Kumle B. , Suttner S. , Haisch G.
Published: March 2003

Background: Point‐of‐care (POC) monitoring may facilitate diagnostic and therapeutic interventions in the critically ill. In a prospective study reliability and costs of two POC lactate testing devices were compared to the central laboratory lactate monitoring method.

Methods: From arterial whole blood and capillary blood samples of 40 intensive care unit (ICU) patients lactate concentrations were measured using either a battery‐powered hand‐held lactate analyser (Accusport®) or a bench‐top blood gas analyser (Chiron 865 series) and compared with lactate measured by the hospital’s central laboratory (‘reference’ method). Measurements were carried out on the day of inclusion in the study (‘baseline’), 8 h later, and in the morning of the 1st, 2nd, and 3rd days thereafter. Costs for blood lactate measurements were analysed for each method.

Results: A total of 197 lactate measurements were done with each system. Lactate measured from arterial blood using the Accusport® and the central laboratory showed excellent agreement (bias: −0.15 mmol/l; relative error: −2.74%). Lactate measured by the blood gas analyser had also excellent agreement with the reference method (bias: 0.09 mmol/l; relative error: 2.24%) and the hand‐held device (bias: −0.24 mmol/l; relative error: −5.06%). Time from blood sampling to availability of data was significantly longer for the central laboratory (85±35 min [range: 45–168 min]) than for both POC systems (range: 1–10 min). Total cost for measuring blood lactate was lowest using the Accusport® device.

Conclusion: The trend towards miniaturizing laboratory monitoring devices will continue, resulting in greater flexibility of management of the critically ill. Blood lactate can rapidly, easily, accurately, and economically be measured at the bedside with the hand‐held monitor apparatus Accusport® and the bench‐top blood gas analyser.
On‐site coagulation monitoring does not affect hemostatic outcome after cardiac surgery
Authors: Capraro L. , Kuitunen A. , Salmenperä M. , Kekomäki R.
Published: March 2003

Background: Rapid coagulation tests are now available for monitoring of bleeding patients after cardiac surgery. As inappropriate blood use in these patients may be due to lack of timely coagulation data, we studied the effect of an algorithm with on‐line coagulation monitoring on transfusions in these patients.

Methods: Prospectively, patients bleeding (>1.5 ml kg−1 15 min−1) after cardiac surgery were randomly assigned to two groups: in group A (n=28), hemostatic treatment during the immediate recovery period (1 h after surgery) was based on an algorithm with on‐site hemostasis monitoring, whereas during the same period group B patients (n=30) were managed solely according to the clinician’s judgement; laboratory tests other than activated clotting time after heparin neutralization were prohibited.

Results: Cumulative chest tube drainage up to 16 h and total transfusion requirements did not differ between the groups. Using a platelet transfusion trigger of 100×109/l, significantly more patients received platelets during the immediate recovery period in the algorithm group than in the control group (14 vs. 3 patients, P=0.001). Desmopressin acetate was administered more often in group A than in group B (8 vs. 2 patients, P=0.04).

Conclusions: Algorithm‐based therapy increased utilization of hemostatic interventions during the immediate recovery period without any obvious benefit to the hemostatic outcome. Re‐evaluation of the platelet transfusion trigger seems warranted.
Effects of different preparations of propofol, diazepam, and etomidate on human neutrophils in vitro
Authors: Heine J. , Jaeger K. , Weingaertner N. , Scheinichen D. , Marx G. , Piepenbrock S.
Published: March 2003

Background: Intravenous anaesthetics and sedatives can influence polymorphonuclear cell (PMN) functions. Some of the drugs for sedation and anaesthesia have been alternatively dissolved in lipid solutions containing medium (MCT) and/or long chain (LCT) triglycerides. The in vitro effects of two different diazepam (benzyl‐alcohol, LCT/MCT), etomidate (propylene‐glycol, LCT/MCT), and propofol (LCT, LCT/MCT) preparations on respiratory burst (RB) and phagocytosis of human PMNs were studied.

Methods: Diazepam (2, 20 μg ml−1), etomidate (0.5, 5 μg ml−1), and propofol (6, 60 μg ml−1) were investigated in clinical and 10‐fold concentrations with flow cytometric assays. The RB was measured with the fluorescent dye rhodamine after induction with Escherichia coli or formyl‐methionyl‐leucylphenylalanine (FMLP) following priming with tumour necrosis factor alpha (TNF‐α). Phagocytosis of PMNs was carried out in whole blood after incubation with fluorescein‐labelled E. coli.

Results: LCT‐propofol at 60 μg ml−1 reduced the percentage of PMNs with RB activity after induction with E. coli (52.8±20.4) and TNF‐α/FMLP (10.8±5.1)) as well as the percentage of phagocytosing PMNs (48.9±19.5) in contrast to LCT/MCT‐propofol, which augmented all parameters (85.4±10.1, 50.3±12.7, 66.5±12.5). Also the higher concentrations of LCT/MCT‐diluted etomidate and diazepam increased the percentage of RB positive PMNs compared to the alternative compositions. The percentage of phagocytosing PMNs was less reduced with 20 μg ml−1 LCT/MCT‐diazepam (85.2±6.9) than with the same concentration of benzyl‐alcohol diluted diazepam (68.8±12.2) compared to the control.

Conclusion: The in vitro effects of diazepam, etomidate, and propofol are dependent on the solvent applied. The tested LCT/MCT preparations reduce the inhibitory effects on the bacterial killing capacity of PMNs found after incubation with propylene‐glycol, benzyl‐alcohol, or LCT preparations, respectively (
Note).
Long‐term outcome after neurosurgically treated spinal epidural abscess following epidural analgesia
Authors: Wang L. P. , Hauerberg J. , Schmidt J. F.
Published: March 2003

Background: A recent investigation demonstrated a high incidence of epidural abscess secondary to epidural catheterization and a 50% frequency of neurologic deficits. We studied short‐ and long‐term neurologic outcome in patients operated for spinal epidural abscess after epidural analgesia.

Methods: Nineteen patients who had undergone neurosurgical decompression and drainage of a spinal epidural abscess during a 5‐year period at three neurosurgical departments in East Denmark were identified by manual review of operating lists.

Results: Median epidural catheterization time was 8 days (range 3–44). Preoperatively 12 patients suffered from inferior paraparesis, one had irradiating pain from the back, and 6 patients had no neurologic deficits. Postoperatively 2 patients had recovered, but 3 other patients had deteriorated; therefore, 13 patients were discharged with paresis/plegia. Seven patients died during a median follow‐up time for all patients of 41.6 months. One patient recovered completely, and one suffered from minor deficits. The remaining patients suffered from paraparesis/plegia or bladder/bowel dysfunction.

Conclusion: Overall recovery rate for patients with paresis/plegia after epidural abscess was 20%. No patients with paresis/plegia following a thoracic abscess recovered in contrast to a 50% recovery rate for patients with lumbar epidural abscess. The majority of long‐term survivors had severe neurologic deficits. Abscess formation contributed to one death.
Evidence that spinal segmental nitric oxide mediates tachyphylaxis to peripheral local anesthetic nerve block
Authors: Wang C. , Sholas M. G. , Berde C. B. , Dicanzio J. , Zurakowski D. , Wilder R. T.
Published: March 2003

Background: Tachyphylaxis to sciatic nerve blockade in rats correlates with hyperalgesia. Spinal inhibition of nitric oxide synthase with NGnitro‐L‐arginine methyl ester (L‐NAME) has been shown to prevent hyperalgesia. Given systemically, L‐NAME also prevents tachyphylaxis. The action of L‐NAME in preventing tachyphylaxis therefore may be mediated at spinal sites. We compared systemic versus intrathecal potency of L‐NAME in modulating tachyphylaxis to sciatic nerve block.

Methods: Rats were prepared with intrathecal catheters. Three sequential sciatic nerve blocks were placed. Duration of block of thermal nocifensive, proprioceptive and motor responses was recorded. We compared spinal versus systemic dose–response to L‐NAME, and examined effects of intrathecal arginine on tachyphylaxis. An additional group of rats underwent testing after T10 spinal cord transection. In these rats duration of sciatic nerve block was assessed by determining the heat‐induced flexion withdrawal reflex.

Results: L‐NAME was 25‐fold more potent in preventing tachyphylaxis given intrathecally than intraperitoneally. Intrathecal arginine augmented tachyphylaxis. Spinalized rats exhibited tachyphylaxis to sciatic block.

Conclusion: The increased potency of intrathecal versus systemic L‐NAME suggests a spinal site of action in inhibiting tachyphylaxis. Descending pathways are not necessary for the development of tachyphylaxis since it occurs even after T10 spinal cord transection. Thus tachyphylaxis, like hyperalgesia, is mediated at least in part by a spinal site of action.
Effect of naloxone on primary and secondary hyperalgesia induced by the human burn injury model
Authors: Brennum J. , Kaiser F. , Dahl J. B.
Published: March 2003

Background: Opioid antagonists may change the responses in models of experimental hyperalgesia. This indicates a possible involvement of the endogenous opioid system in these models. The aim of the present study was to evaluate whether activation of the endogenous opioid system could be demonstrated in the human burn injury model of cutaneous hyperalgesia, using an intravenous challenge with the non‐selective opioid antagonist naloxone.

Methods: We studied 25 healthy male volunteers aged 20–31 yrs in a randomised, double‐blind, triple crossover design. A 25×50 mm rectangular burn injury was produced on the calf on 3 separate days, at least 1 week apart. Subjects received an intravenous bolus dose of naloxone 0.4 mg, 10 mg or placebo 3 h after induction of the burn injury.

Results: Primary and secondary hyperalgesia was induced by the burn injury. Naloxone did not affect any of the measured variables: heat pain detection threshold in non‐injured or injured tissue, pain produced by short or prolonged noxious heat in non‐injured or injured tissue, secondary hyperalgesia elicited by pin prick or stroke, or pain produced by short or prolonged noxious mechanical stimulation in non‐injured tissue. No significant adverse effects of naloxone were encountered.

Conclusions: Activation of an endogenous opioid response following induction of hyperalgesia in human volunteers by a burn injury could not be demonstrated with an intravenous naloxone challenge. These findings suggest that the endogenous opioid response is not a confounding factor in this model.
Comparison of lignocaine 2% with adrenaline, bupivacaine 0.5% with or without hyaluronidase and a mixture of bupivacaine, lignocaine and hyaluronidase for peribulbar block analgesia
Authors: Van den Berg A. A. , Montoya‐Pelaez L. F.
Published: March 2003

Purpose: Each of the freely available local analgesic agents may be used, alone or in combination, with or without hyaluronidase, epinephrine and sodium bicarbonate for peribulbar block analgesia (PBA). A prospective audit of four solutions was undertaken to rationalize choice of local analgesic agent for PBA.

Methods: A randomized, prospective study on 200 middle‐aged to elderly patients undergoing cataract extraction was undertaken to compare the efficacy of: (1) bupivacaine 0.5% (bup 0.5% plain); (2) bupivacaine 0.5% plus hyaluronidase 100 i.u. ml−1 (bup 0.5% hyalase); (3) lidocaine 2% plus epinephrine 1:200 000 (lido 2% epi); or (4) a mixture of lidocaine 2% and bupivacaine 0.5% (2:3 volume per volume mix) containing hyaluronidase 25 i.u. ml−1 (lido/bup/hyalase). A standardized deep peribulbar block technique, akinesia scoring system (each 5 min×4), and supplemental protocol was followed. Onset of block and supplementation rates to achieve akinesia were recorded by a blinded observer; the requirement for augmentation with topical oxybuprocaine or subconjunctival lidocaine during surgery and the time from first PBA injection to the completion of surgery (the duration of surgical access) were also recorded.

Results: Groups (N=50) were comparable. Akinesia scores were similar after each agent at 5 min, better with lido 2% epi compared with bup 0.5% plain at 10 min (P<0.05), and better with bup 0.5% hyalase, lido 2% epi, and lido/bup/hyalase, than with bup 0.5% plain at 15 min (P<0.01, <0.01, <0.05, respectively) and at 20 min (P<0.05, <0.05, <0.025, respectively). The supplementation rate at 5 min was least with lido 2% epi, greater with bup 0.5% plain (P<0.01) and bup 0.5% hyalase (P<0.0005) and greatest with lido/bup/hyalase (P<0.0005), but similar in each group at 10, 15 and 20 min. Overall, those given lido 2% epi required the least number of supplemental injections to achieve globe akinesia. Mean supplemental injectate volumes, augmentation rates during surgery and the durations of surgical access provided by each agent were similar.

Conclusion: All four agents provided adequate analgesia during cataract extraction lasting approximately 95–100 min after PBA injection. Lido 2% epi demonstrated most rapid onset and required least number of injections to establish block. A hyaluronidase effect was evident only after 15 min in the bup 0.5% hyalase and lido/bup/hyalase groups. Bup 0.5% plain was overall the least satisfactory, and the greatest supplementation rate occurred with lido/bup/hyalase, suggesting that either lido 2% epi or bup 0.5% hyalase are the most suitable of the agents tested for this type of surgery.
A comparison of 0.5% ropivacaine and 1% mepivacaine for sciatic nerve block in the popliteal fossa
Authors: Fernández‐Guisasola J. , Andueza A. , Burgos E. , Plaza A. , Porras M. C. , Reboto P. , Rivera J. C. , García Del Valle S.
Published: March 2003

Background: The purpose of this study was to compare anesthetic efficacy and postoperative analgesia of 0.5% ropivacaine and 1% mepivacaine for sciatic nerve block in the popliteal fossa (popliteal block).

Methods: A prospective, double‐blind study was carried out in 58 adult patients scheduled for outpatient foot or ankle surgery. They were randomized to receive popliteal block with 40 ml of either 0.5% ropivacaine (group R) or 1% mepivacaine (group M). An atraumatic, Teflon‐coated needle connected to a neurostimulator was used to make a single puncture using a posterior approach. The times to onset of sensory and motor block, and the need for intraoperative sedation were recorded. Before discharge, patients were asked to document the time to first analgesic use, time to return of full sensation in the foot, and their evaluation of the technique.

Results: Onset time (mean±standard deviation, 95% confidence interval) of both sensory block (6.5±5.1 min, 4.47–8.49, in group R and 6.2±3.7 min, 4.83–7.69, in group M) and motor block (6.6±4.4 min, 4.81–8.23, in group R and 7.9±4.1 min, 6.29–9.53, in group M) was similar in both groups. Postoperative analgesia lasted longer in group R (15.2±5.1 h, 13.25–17.21) than in group M (5.7±1.8 h, 5.01–6.41; P<0.001). Duration of sensory block was longer in group R (20.7±6.2 h, 18.51–23.01) than in group M (6.5±1.7 h, 5.86–7.16; P<0.001). Acceptance of the anesthetic procedure was similar in both groups.

Conclusion: In this study we demonstrated that both 0.5% ropivacaine and 1% mepivacaine for popliteal block produced rapid, effective and safe anesthesia but postoperative analgesia was more long‐lasting with ropivacaine.
Intracerebral microdialysis and bedside biochemical analysis in patients with fatal traumatic brain lesions
Authors: Ståhl N. , Mellergård P. , Hallström A. , Ungerstedt U. , Nordström C. H.
Published: March 2003

Background: Microdialysis with bedside biochemical analysis was used to monitor cerebral biochemical alterations that precede and accompany increase in intracranial pressure (ICP), resulting in a complete cessation of cerebral blood flow.

Methods: Seven patients, who died due to an untreatable increase in ICP, were included. The patients originate from a large, consecutive series of severely head injured patients (n: 95) monitored with intracerebral microdialysis (perfusion rate 0.3 μl/min). One microdialysis catheter was inserted via a separate burr hole frontally to that used for the intraventricular catheter (”better” position) and one catheter was inserted into cerebral cortex surrounding an evacuated focal contusion or underlying an evacuated haematoma (”worse” position). Biochemical analyses of glucose, lactate, glycerol, urea, glutamate, and pyruvate were performed at the bedside. All samples were frozen for subsequent HPLC (high‐performance liquid chromatography) analyses of amino acids and ions.

Results: Decreases in glucose and pyruvate and increases in lactate, glycerol, glutamate, and lactate/pyruvate (la/py) ratio characterized cerebral ischaemia. The measured markers give information regarding substrate availability (glucose), redox state of the tissue (la/py ratio), degradation of glycerophospholipids in cell membranes (glycerol), and extracellular concentration of excitatory amino acids (glutamate). In the “worse” position biochemical deterioration occurred before the increase in ICP. In the “better” position biochemical deterioration was usually observed after the increase in ICP.

Conclusion: Changes of cerebral energy metabolism that accompany cerebral ischaemia follow a certain pattern and may be detected at the bedside by intracerebral microdialysis before the secondary damage causes an increase in ICP.
Propofol and gastric effects of morphine
Authors: Hammas B. , Thörn S.‐E. , Wattwil M.
Published: March 2003

Objective: The purpose of this study was to evaluate whether propofol abolishes morphine‐induced effects on gastric emptying and gastric tone.

Method: The study was carried out before anesthesia in 40 patients (ASA I–II). Gastric tone was measured in 20 patients by an electronic barostat. Volume changes were thereby registered continuously in an intragastric flaccid bag with a constant preset pressure. All patients received i.v. morphine 0.1 mg · kg−1 before the measurements and, in a randomized order, 10 of the patients also received a bolus dose of propofol 1 mg · kg−1 before morphine. Gastric emptying was studied with the paracetamol method in 20 patients. All patients received morphine 0.1 mg · kg−1 i.v. 10 min before oral ingestion of 1.5 g paracetamol in 200 ml water and, in a randomized order, 10 of the patients also received propofol, a bolus dose of 0.3 mg · kg−1 before morphine, followed by an infusion of 1 mg · kg−1 · h−1 during the whole study (2 h).

Results: The volume in the intragastric bag increased in all patients receiving morphine without propofol. In the group that received propofol before morphine, the volume in the intragastric bag decreased in all patients. The volume differences between the groups were statistically significant (P<0.01). There were no statistically significant differences of the AUC60, Cmax and Tmax of serum paracetamol concentrations between the morphine and propofol‐morphine groups.

Conclusion: Propofol did not abolish morphine‐induced delay of gastric emptying even if propofol abolished the decrease of gastric tone induced by morphine.
Vocal cord paralysis as a consequence of peritonsillar infiltration with bupivacaine
Authors: Weksler N. , Nash M. , Rozentsveig V. , Schwartz J. A. , Schily M. , Gurman G. M.
Published: March 2003

Reduction of postoperative pain is an important goal in the perioperative management of tonsillectomy patients. This is particularly the case for children, who often exhibit resistance to intramuscular or rectal administration of drugs. Peritonsillar bupivacaine infiltration, a relatively safe method of pain control, is in some centers frequently used by otolaryngologists for pain relief. We present the case of a 5‐year‐old girl who developed bilateral vocal cord paralysis following preoperative peritonsillar bupivacaine infiltration. After an uneventful tonsillectomy and extubation, stridor and respiratory distress developed. Bilateral vocal cord paralysis was seen on laryngoscopy. The patient was reintubated and five hours later was successfully extubated without further sequelae. Anesthesiologists and surgeons should be aware of this uncommon complication than can occur with the use of peritonsillar bupivacaine infiltration for pain control in tonsil surgery.
Opioids in cancer and chronic non‐cancer pain therapy – indications and controversies
Authors: Breivik H.
Published: March 2003

Indications for strong opioids for cancer‐related pain as well as for chronic non‐cancer pain are that non‐opioid drugs, and other less risky therapies, fail and that the pain is opioid‐sensitive. The WHO analgesic ladder principle continues to serve as an excellent educational tool in the efforts by WHO in collaboration with the World Federation of Societies of Anaesthesiologists (WFSA) and The International Association for the Study of Pain (IASP) to increase knowledge of pharmacological pain therapy and increase availability of essential opioid analgesics world‐wide. Opioids differ in pharmacodynamics and pharmacokinetics, and patients have different pharmacogenetics and pain mechanisms. Sequential trials of the increasing numbers of available opioid drugs are therefore appropriate when oral morphine fails.

Controversies continue concerning diagnosis and handling of opioid‐insensitive pain in cancer and chronic non‐cancer pain, opioid‐induced neurotoxicities, risks of tolerance, addiction, pseudo‐addiction, and methods for improving effectiveness and decreasing adverse effects of long‐term opioid therapy, treating breakthrough pain with immediate release oral and transmucosal opioids.

Consensus guidelines have recently been developed in the Nordic countries concerning the ethical practice of palliative sedation when opioids and other pain‐relieving therapies fail in patients soon to die. Guidelines for long‐term treatment with strong opioids of chronic non‐cancer‐related pain are also being developed in the Nordic countries, where very diverging traditions for the usage of such therapy still exist.
Symptom recognition in advanced cancer. A comparison of nursing records against patient self‐rating
Authors: Strömgren A. S. , Groenvold M. , Sorensen A. , Andersen L.
Published: March 2003

The aim of the study was to investigate the extent to which the symptoms experienced by advanced cancer patients were covered by the nursing records. On the day of the first contact with our palliative care department, a nursing record was taken, and on this or the following day, 56 patients filled in the questionnaires EORTC Quality of Life Questionnaire (EORTC QLQ‐C30), Edmonton Symptom Assessment System (ESAS), and Hospital Anxiety and Depression Scale (HADS). In each patient, the symptomatology reported in the patient‐completed questionnaires was compared with the symptomatology mentioned by the nurse in the nursing record. The analysis revealed good concordance concerning pain and poor physical functioning, but patients reported other symptoms or problems much more often than their nurses. Reasons for these discrepancies are discussed. It is suggested that the nurse’s knowledge of the patient’s symptomatology might gain from more systematic screening or from transfer of information from patient self‐assessment questionnaires to the nursing records.
Nerve blocks in chronic pain therapy – are there any indications left?
Authors: Stanton‐Hicks M.
Published: March 2003

Although diagnostic imaging is now highly developed, neural blockade provides another opportunity to test for a source of pain that may frequently leave no signature. Likewise, many neuropathic pains can not be tested by neurodiagnostic methods. This paper makes a case for the continued use of regional anesthesia to assist in the diagnosis and therapy of chronic pain. In particular, the example of autonomic blocks and blocks of the axial spine are emphasized. Nerve blocks require an understanding of the anatomy, physiology, pharmacology, and the ability to interpret critically their results.
Has basic research contributed to chronic pain treatment?
Authors: Jensen T. S. , Gottrup H. , Kasch H. , Nikolajsen L. , Terkelsen A. J. , Witting N.
Published: March 2003

Our understanding of nociceptive processing and of plastic changes after persistent noxious input has increased immensely within the last two decades. It is now clear that long‐lasting noxious stimulation or damage to the nervous system give rise to a neuronal hyperexcitability and that this sensitisation of the nervous system plays an important role for development and maintenance of chronic pain. The manifestations of such hyperexcitability are numerous and include among others: increased neuronal response to a suprathreshold stimulus, expansion of the peripheral areas from where a central neurone can be activated and the recruitment of previous non‐responding nociceptive neurones. Furthermore, it has been possible to modulate this neuronal hyperexcitability by the discovery of molecular targets for pain, by sequencing DNA of ion channels and receptors and by development of new molecules that exert their effects on these molecular targets. The changes in responsiveness appear to be partly time and intensity dependent and partly dependent on the cause of injury. Whereas relatively short‐lasting and moderate noxious input leads to reversible plastic changes, more intense and long‐lasting noxious stimulation implies a risk for persistent and more profound alterations in transmitters, receptors, ion channels and in neuronal connectivity. Despite the explosion of new knowledge in pain processing and in molecular background for neuroplasticity, this progress has unfortunately not resulted in a corresponding improvement of our ability to treat chronic pain. The number of patients with chronic unrelieved pain is still high and newer types of treatment have so far not resulted in a substantially better treatment. Nevertheless, there is now an ongoing systematic research in which chronic pain conditions are assessed in a fashion so that mechanisms underlying pain can be dissected. Moreover, controlled clinical trials together with systematic reviews are carried out which in the future should permit formulation of treatment algorithms for chronic pain. Finally, it is likely that the development of new specific types of treatment will show efficacy if they are evaluated and analysed not on the global pain experience, but more specifically on those targets and elements of the pain experience they are aimed to deal with.