bluuebunny/crossref_metadata_2025 huggingface dataset:
Perineural antinociceptive effect of opioids in a rat model
Authors: Grant G. J. , Vermeulen K. , Zakowski M. I. , Langerman L.
Published: March 2003

Background: The research on conductive analgesia induced by perineural opioids generated a large body of conflicting data. In this study we reassessed the antinociceptive response to perineural administration of morphine, fentanyl or meperidine in a rat model.

Methods: Analgesia was assessed using the hind paw withdrawal latency (HPWL) response to radiant heat. The opioid dose producing 20% of maximal possible effect (20%MPE) for systemic analgesia was calculated for each drug. Then sciatic blockade was performed with the dose corresponding to 20%MPE. The injected hind paw was used to measure direct perineural effect and the contralateral hind paw was used as an indicator of systemic effect.

Results: The response latency produced by morphine or fentanyl was not significantly different for ipsilateral (perineural effect) or contralateral (systemic effect) paw (27±11 vs 28±16 and 3l±16 vs 23±16 s, respectively). However, the meperidine group showed significantly higher %MPE for the ipsilateral paw (79±32 s) than for the contralateral paw (27±22 s).

Conclusions: The results indicate that perineural fentanyl or morphine do not produce analgesia. Perineural block produced by meperidine was attributed to local anesthetic‐like effect, rather than to drug interaction with opioid receptor.
Plasma concentrations and pharmacokinetics of bupivacaine with and without adrenaline following caudal anaesthesia in infants
Authors: Hansen T. G. , Morton N. S. , Cullen P. M. , Watson D. G.
Published: March 2003

Background: The aim of this study was to determine whether the use of adrenaline 1/400 000 added to 0.25% bupivacaine significantly delays the systemic absorption of the drug from the caudal epidural space in young infants.

Methods: Fifteen infants less than 5 months of age undergoing minor lower abdominal procedures under a standardised general anaesthetic were randomised to receive a caudal block with either 0.25% plain bupivacaine 2.5 mg/kg (n=7) or bupivacaine 0.25% with 1/400 000 adrenaline (n=8). Blood samples were drawn at 30, 60, 90, 180, 240 and 360 min according to the infant’s weight and analysed for total and free bupivacaine concentrations using a gas chromatography‐mass spectrometry (GC‐MS) technique.

Results: The total CMAX and TMAX were comparable in both groups. The total bupivacaine concentration at t=360 min was significantly higher in the “adrenaline” group compared to the “plain” group, i.e. a median (range) 742 ng/ml (372–1423 ng/ml) vs. 400.5 ng/ml (114–446 ng/ml), P=0.0080. The median “apparent” terminal half‐life (t½) was significantly longer in the “adrenaline” group (363 min; range 238–537 min) compared to the “plain” group (n=6) (165 min; range 104–264 min), P=0.0087. The free bupivacaine concentrations (n=3 in both groups) ranged between 13 ng/ml and 52 ng/ml, corresponding to a percentage of free bupivacaine between 1.3% and 6.7%.

Conclusion: The addition of 1/400.000 adrenaline prolongs the systemic absorption of caudally administered bupivacaine in infants less than 5 months of age.
Complaints related to respiratory events in anaesthesia and intensive care medicine from 1994 to 1998 in Denmark
Authors: Rosenstock C. , Møller J. , Hauberg A.
Published: March 2003

Background: In Denmark, a National Board of Patients’ Complaints (NBPC) was founded in 1988. This study analyses anaesthetic complaints related to adverse respiratory events filed at the NBPC from 1994 to 1998 to point out directions for possible preventive measures.

Methods: All decisions made by the NBPC from 1994 to 1998 concerning personnel employed in the Danish health care system were scrutinized. Cases related to anaesthesia and intensive care medicine were reviewed. Adverse respiratory events were identified and classified by mechanism of the incident that had caused the complaint. Detailed information on anaesthetic technique, personnel involved, sequence of events, clinical manifestation of injury, and outcome was recorded.

Results: A total of 284 cases was identified. One‐fifth (n=60) of the complaints were related to an adverse respiratory event. The overall mortality in these cases was 50% (n=30). In 19 complaints (32%), the treatment was considered substandard.

Conclusion: Complaints related to respiratory events reveal that inadequate anaesthetic and intensive care medicine treatment leads to patient damage and death. Preventive strategies should be directed at the development of guidelines for handling the difficult airway, education in the management of the difficult airway, instruction in the correct use of anaesthetic equipment, improvement of interpersonnel communication routines, as well as implementation of simulator training.
Myopexy (Faden) results in more postoperative vomiting after strabismus surgery in children
Authors: Saiah M. , Borgeat A. , Ruetsch Y. A. , Seifert B. , Klainguti G.
Published: March 2003

Background: Strabismus correction in children is associated with a high incidence of postoperative nausea and vomiting. The purpose of this prospective, double‐blind study was to examine the influence of the surgical method for correction of squint on the incidence of postoperative vomiting.

Methods: One hundred and twenty consecutive children aged 2–12 years, scheduled for elective strabismus surgery, were enrolled in this prospective, double‐blind study. A standardised total intravenous anaesthesia was given to all children. The development of perioperative oculocardiac reflex was noted and the number of episodes of vomiting during the first 48 h postoperatively was recorded. At the completion of the study, the children who were operated with myopexy according to Faden, were allocated to a Faden group, those without a myopexy to the non‐Faden group. All the patients included in this study were operated on by the same surgeon with standardised techniques.

Results: The Faden group was younger, lighter and the operation time was longer (P<0.05). The incidence of vomiting was greater in the Faden group; 53% versus 12% (P<0.05). The incidence of oculocardiac reflex was similar in both groups; 40% in the Faden versus 28% in the non‐Faden group, respectively. The total dose of propofol and alfentanil was similar between the groups. Requirement of analgesics for postoperative pain was similar in both groups. The only independent risk factor for postoperative vomiting was the Faden operation.

Conclusion: The surgical method used for strabismus correction in children has a great influence on the incidence of postoperative vomiting. The Faden operation is associated with a very high incidence of postoperative vomiting; this particular group of patients has to be considered as a high risk group for postoperative vomiting and deserves an antiemetic prophylaxis.
Continuous positive pressure ventilation during epidural blockade – effects on cardiac output distribution
Authors: Elowsson P. , Norlén K. , Jakobson S.
Published: March 2003

Background: It has been shown that when cardiac output (CO) decreases during continuous positive pressure ventilation (CPPV), its regional distribution adapts with a favouring of vital organs. Does epidural blockade modify this adaptation?

Methods: Regional blood flows were assessed by the microsphere technique (15 μm) in 17 anaesthetised pigs during spontaneous breathing and CPPV with 8 cm H2O end‐expiratory pressure (CPPV8) before and after epidural blockade. The block was induced at either the Th6–7 (Thep) or the L6–S1 (Lep) level with 1 ml of lidocaine 40 mg · ml−1.

Results: When Lep was combined with CPPV8, mean arterial pressure and CO decreased significantly, and they decreased even more when combined with Thep. In contrast, the relative perfusion of the central nervous system, heart and kidneys remained stable during the four conditions studied. The adrenal perfusion during CPPV8 was obviated by epidural blockade. The absolute and relative perfusion of the skeletal muscle decreased during epidural blockade. The administered doses of epidural lidocaine did not affect blood flow in the spinal cord.

Conclusions: The locally mediated nutritive vasoregulation of vital organs outweighed the sympathetic blockade induced by epidural blockade. During Thep blockade the animals were less capable of responding to the haemodynamic changes induced by CPPV8, probably due to the blockade of the cardiac part of the sympathetic nervous system.
Validation of a new respiratory inductive plethysmograph
Authors: Leino K. , Nunes S. , Valta P. , Takala J.
Published: March 2003

Background: The respiratory inductive plethysmograph (RIP) can be used to monitor changes in end‐expiratory lung volume (ΔEELV), and thus, used in intensive care when evaluating positive end‐expiratory pressure (PEEP)‐induced changes in lung volumes in order to optimise the ventilator settings. We validated the newest model of RIP (Respitrace PlusTM), both under laboratory and clinical conditions, and made a comparison with a previously validated RIP (RespigraphTM) in the measurement of tidal volume (VT), long‐term EELV and PEEP‐induced acute ΔEELV.

Methods: The in vitro validation was performed using a lung model and the in vivo evaluation in five spontaneously breathing normal subjects, four patients with acute lung injury (ALI) and eight anaesthetised patients.

Results: The difference in VT values during PEEP manipulations between pneumotachometer (PNT) and RIP in spontaneously breathing volunteers and mechanically ventilated ALI patients was 0.1±0.9% (mean±SEM) and −5.2±0.6, respectively (effect of device NS). In anaesthetised patients, the difference between the new RIP and spirometer in the measurement of PEEP‐induced acute ΔEELV was −2.6±1.5% (PEEP‐device interaction, P<0.05). In ALI patients, the difference between PNT and RIP in the measurement of PEEP‐induced acute ΔEELV was 1.0±9.7% (NS). The new RIP had a baseline drift over 50‐fold when cold and over 10‐fold when warm compared to the old RIP in vitro.

Conclusion: The new RIP is accurate enough for clinical and research purposes in the measurement of VT. Semiquantitative measurements of acute ΔEELV can be done with accuracy sufficient for clinical use, but long‐term ΔEELV monitoring is not possible. The new RIP should be kept on for several hours before measurements to minimise the drift.
Bilateral pulmonary edema after endoscopic sympathectomy in a patient with glucose‐6‐phosphate dehydrogenase deficiency
Authors: Lan C.‐J. , Luk H.‐N. , Wu C.‐T. , Chang W.‐K. , Tsou M.‐Y. , Lui P.‐W. , Lee T.‐Y.
Published: March 2003

Transaxillary endoscopic sympathectomy of thoracic ganglia (T2–T3) has recently gained wider acceptance as the treatment of choice for palmar hyperhidrosis. It requires one‐lung ventilation to facilitate the surgery. One‐lung ventilation, however, is not without complications, among which acute pulmonary edema has been reported. In this case report, we present a patient with palmar hyperhidrosis complicated by glucose‐6‐phosphate dehydrogenase (G‐6‐PD) deficiency, who received bilateral endoscopic sympathectomy under alternate one‐lung anesthesia, and developed acute pulmonary edema immediately after recruitment of the successive collapsed lung. The effects of hypoxemia, G‐6‐PD deficiency and sympathectomy might all add to the development of acute pulmonary edema secondary to reexpansion of each individual lung after alternate one‐lung ventilation. The possibilities of the inferred causes are herein discussed.
Warning! Suctioning. A lung model evaluation of closed suctioning systems
Authors: Stenqvist O. , Lindgren S. , Kárason S. , Söndergaard S. , Lundin S.
Published: March 2003

Background: Closed system suctioning, CSS, has been advocated to avoid alveolar collapse. However, ventilator manufacturers indicate that extreme negative pressure levels can be obtained during closed system suctioning, impeding the performance of the ventilator.

Methods: Suctioning with a 12 or 14 Fr catheter with a vacuum level of −50 kPa was either performed with an open technology or a CSS, where the catheter is introduced through a tight‐fitting connection through the endotracheal tube, ETT. The lung model was ventilated with a Servo 900C or 300 ventilator with an I:E ratio of 1:2, 1:1 and 2:1 and extrinsic positive end‐expiratory pressure (PEEP) at 0 or 10 cm H2O. Respiratory volumes and alveolar pressure were measured at the lung model alveolus.

Results: The initial suctioning flow was >40 l/min with a 14 Fr catheter. When inserting the catheter through a no. 7 ETT, PEEP rose from 11 to 23 cm H2O during volume control ventilation with an I:E ratio 1:1. During suctioning the alveolar pressure fell to 10 cm H2O below the set PEEP level. CSS during pressure control ventilation had fewer effects. Low tidal volumes, inverse I:E ratio and secretions in the tube resulted in pressures down to −92 cm H2O.

Conclusion: CSS should not be used in volume control ventilation due to risk of high intrinsic PEEP levels at insertion of the catheter and extreme negative pressures during suctioning. Pressure control ventilation produces less intrinsic PEEP effect. The continuous positive airway pressure (CPAP) mode offers the least intrinsic PEEP during insertion of the catheter and least sub‐atmospheric pressure during suctioning.
Direct tracheal airway pressure measurements are essential for safe and accurate dynamic monitoring of respiratory mechanics. A laboratory study
Authors: Kárason S. , Søndergaard S. , Lundin S. , Wiklund J. , Stenqvist O.
Published: March 2003

Background: All monitoring of respiratory mechanics should depend on tracheal pressures (Trach‐P) as endotracheal tube resistance (ETT‐Res) will otherwise distort them. The aim of this study was to investigate factors that may vary ETT‐Res, causing difficulties in ETT‐Res estimation clinically, and to evaluate a method for direct Trach‐P measurements to obviate these problems.

Methods: In a model we studied: 1) The influence on ETT‐Res caused by different connectors and secretions; 2) Direct Trach‐P measurements with a catheter (o.d. 2 mm, i.d. 0.9 mm) with either end or side hole, filled with either air or liquid, introduced through the ETT lumen and evaluated regarding response time and position.

Results: The pressure drop between trachea and Y‐piece increased by 15% when respectively a swivel connector and a humidification device were connected to the ETT. When injecting 1 ml and 2 ml gel into the ETT lumen the inspiratory resistance increased 100% and 600% respectively. The response time of all catheters was ≤12 ms. During constant flow in inspiratory and expiratory directions the pressure difference between an end hole catheter positioned from 2 cm above the ETT tip to 4 cm below and a reference pressure in the artificial trachea was less than 1.5 cmH2O.

Conclusions: ETT connections and secretions cause a variance in resistance. Tracheal pressure can be measured with high precision with an air‐ or liquid‐filled catheter. An end hole catheter placed within 2 cm above or below the ETT tip will give sufficiently precise measurements for clinical purposes.
Transient neurologic symptoms after spinal anaesthesia using isobaric 2% mepivacaine and isobaric 2% lidocaine
Authors: Salazar F. , Bogdanovich A. , Adalia R. , Chabás E. , Gomar C.
Published: March 2003

Background: Transient Neurological Symptoms (TNS) syndrome following subarachnoid anaesthesia was initially associated with hyperbaric lidocaine 50 mg/ml, but has also been reported with most local anaesthetics, including hyperbaric mepivacaine 40 mg/ml. The aim of this study was to determine the incidence of TNS after subarachnoid anaesthesia using isobaric mepivacaine 20 mg/ml and isobaric lidocaine 20 mg/ml.

Methods: Eighty patients of both sexes, ASA class I–II, scheduled for elective minor orthopaedic surgery under subarachnoid anaesthesia, were prospectively included and randomly allocated to receive 40–60 mg of either isobaric mepivacaine 20 mg/ml (Group M) or isobaric lidocaine 20 mg/ml (Group L). Patients were evaluated on the first postoperative day by one investigator unaware of the grouping, looking for symptoms suggestive of TNS, such as pain or dysaesthesias in the buttocks or lower limbs with or without back pain.

Results: TNS symptoms were observed in three patients (7.5%) of Group M and in one patient (2.5%) of Group L, without statistically significant differences between the groups. Symptoms had an abrupt onset and relief, lasted from 45 min to 24 h, and had a complete resolution without sequelae. The only statistically significant difference between groups was longer motor blockade in Group M (P=0.0031).

Conclusion: In this study TNS was associated with isobaric mepivacaine 20 mg/ml, with an incidence of 7.5%, and with isobaric lidocaine 20 mg/ml, with an incidence of 2.5%, in patients having orthopaedic procedures in the supine position.
Pharmacokinetics and drug dosing adjustments during continuous venovenous hemofiltration or hemodiafiltration in critically ill patients
Authors: Bugge J. F.
Published: March 2003

Continuous renal replacement therapy (CRRT) in critically ill patients with renal failure may significantly increase drug clearance, requiring drug dosing adjustments. Drugs significantly eliminated by the kidney often undergo substantial removal during CRRT, and a supplemental dose corresponding to the amount of drug removed by CRRT should be administered. Clearance by CRRT can either be measured or estimated. The high‐flux membranes used in CRRT make no filtration barrier to most drugs, and the filtrate concentration can be estimated by the unbound fraction of the drug in plasma. When adding dialysis to filtration, this approach overestimates drug clearance, and a correcting factor should be used. A method for estimating drug clearance as a function of creatinine clearance is also suggested, but it has the same limitations in overestimating drug clearance when dialysis is combined with filtration. For non‐toxic drugs, doses can safely be increased 30% above actual estimates to ensure adequate dosing. For drugs with a narrow therapeutical margin, monitoring plasma concentrations are mandatory. When appropriate, the use of a readily available reference for drug dosing is recommended.
Chronic post‐sternotomy pain
Authors: Kalso E. , Mennander S. , Tasmuth T. , Nilsson E.
Published: March 2003

Background: Chronic postoperative pain is a well‐recognised problem. The incidence of severe incapacitating pain is about 3–5% after various types of surgery such as thoracotomy, repair of inguinal hernias and mastectomy. Sternotomy causes considerable postoperative pain and patients with chronic post‐sternotomy pain are often referred to pain clinics. Epidemiological studies on chronic post‐sternotomy pain are scarce, however. The aim of this paper was to study the incidence and possible risk factors of chronic pain following sternotomy operations performed for coronary bypass grafting or thymectomy.

Methods: Two groups of patients were studied for persistent pain following sternotomy operations. A questionnaire was sent in January 1997 to 71 patients with myasthenia gravis (MG) who had undergone a thymectomy during 1985–1996 and 720 patients who had had coronary bypass grafting (CABG) in 1994 were interviewed by letter. The patients were asked about the presence of pain and other symptoms in the chest, shoulders, arms or legs that they thought were connected to surgery. They were also asked about the quality of the pain and its evolvement with time. The patients’ records were checked for details about surgery, anaesthesia and the state of the coronary disease.

Results: The response rate was 87%. The interval between the interview and surgery varied from 6 months to 12 years in the MG group and it was 2–3 years in the CABG group. In the MG group, 27% of the patients reported chronic post‐sternotomy pain, which was moderate to severe in 48% of the patients. In the CABG group, 28% of the patients still had post‐sternotomy pain, which was moderate to severe in 38% of patients. Of the patients who had post‐sternotomy pain, one‐third reported sleep disturbances due to the pain.

Conclusion: Chronic post‐sternotomy pain is an important complication that may have a significant impact on the patient’s everyday life. Future studies will show whether minimising complications, improving postoperative care and starting early adequate pain management will reduce the incidence of this problem.
The incidence of chronic post‐sternotomy pain after cardiac surgery – a prospective study
Authors: Meyerson J. , Thelin S. , Gordh T. , Karlsten R.
Published: March 2003

Background: Post‐sternotomy pain is sometimes a sequela of cardiac surgery. The incidence, characteristics and clinical course of post‐sternotomy pain are not well known. The aim of our study was to determine the incidence of chronic post‐sternotomy pain in patients undergoing sternotomy for cardiac surgery in general and according to the specific surgical procedure.

Method: In a prospective manner, a group of 349 consecutive patients were evaluated for chronic post‐sternotomy pain one year after surgery. The patients were asked in a postal questionnaire to describe and score any persistent pain following the surgical procedure. The patients were classified into 3 sub‐groups according to surgical procedure. The first group consisted of patients operated for coronary artery by‐pass grafting (CABG) including internal thoracic artery grafting (ITAG). The second group included patients operated with CABG without ITAG and the third group of patients with valve replacement without CABG.

Result: A total of 318 patients (91%) answered the questionnaire of whom 90 (28%) reported chest discomfort different from what they experienced before surgery. The scoring on the visual analogue scale (VAS, 0–100 mm) showed that 41 patients (13%) reported maximum pain intensity ≥30 mm (moderate pain), and 14 of these patients (4%) scored ≥54 mm (severe pain). There was no statistically significant difference in pain incidence and pain intensity when comparing the patients subjected to different surgical procedures.

Conclusions: This prospective study shows that the overall incidence of non‐cardiac pain after sternotomy for cardiac surgery is high (28%). Most patients experience a modest pain intensity but some (1%) report severe pain, never being lower than 54 mm on VAS. The study also indicates that the incidence of pain after sternotomy is not only associated with harvest of the ITA and additional aetiological factors must be sought.
Effects of remifentanil/propofol in comparison with isoflurane on dynamic cerebrovascular autoregulation in humans
Authors: Engelhard K. , Werner C. , Möllenberg O. , Kochs E.
Published: March 2003

Background: This study investigates the effects of remifentanil and propofol in comparison to isoflurane on dynamic cerebrovascular autoregulation in humans.

Methods: In 16 awake patients dynamic cerebrovascular autoregulation was measured using transcranial Doppler sonography (TCD). Thereafter patients were intubated, ventilated with O2/air (FiO2=0.33) and randomly assigned to one of the following anesthetic protocols: group 1 (n=8): 0.5 μg · kg−1 · min−1 remifentanil combined with a propofol‐target plasma concentration of 1.5 μg · ml−1; group 2 (n=8): 1.8 % isoflurane (1.5 MAC). Following 20 min of equilibration the autoregulatory challenge was repeated. Arterial blood gases and body temperature were maintained constant over time. Statistics: Mann‐Whitney U‐test and Wilcoxon signed‐rank test.

Results: Dynamic autoregulation was intact in all patients prior to induction of anesthesia expressed by an autoregulatory index (ARI) of 5.4±1.21 (mean±SD, group 1) and 5.9±0.98 (mean±SD, group 2). With remifentanil/propofol anesthesia dynamic autoregulation was similar to the awake state (group 1: ARI=4.9±0.88). In contrast, autoregulatory response was delayed with 1.5 MAC isoflurane (group 2, ARI=2.1±0.92) (P<0.05).

Conclusion: These data show that dynamic cerebrovascular autoregulation is maintained with remifentanil‐based total intravenous anesthesia. This is consistent with the view that narcotics (and hypnotics) do not alter the physiologic cerebrovascular responses to changes in MAP. In contrast, 1.5 MAC isoflurane delays cerebrovascular autoregulation compared to the awake state.
Moderate hypothermia blunts the inflammatory response and reduces organ injury after acute haemorrhage
Authors: Gundersen Y. , Vaagenes P. , Pharo A. , Valø E. T. , Opstad P. K.
Published: March 2003

Background: Reduced body temperature is a common companion to trauma/haemorrhage. Several clinical studies have identified hypothermia as an independent risk variable predisposing to increased morbidity and mortality. At the same time it is known that most enzymatic reactions are downregulated at temperatures below 37°C. Theoretically this should restrain the inflammatory response and protect the host from remote organ injury. The study was performed to test this hypothesis.

Methods: Twenty‐six male Sprague Dawley rats were used for the experiments. Volume controlled haemorrhagic shock was induced by withdrawal of 2.5 ml blood/100 g body weight over 10 min. Half of the animals (n=13) were then cooled to 32.5–33°C, the other half (n=13) were kept normothermic (37.5±0.5°C). Seventy‐five minutes after initiation of bleeding, two‐thirds of the blood was retransfused. Thereafter the rats were observed for 2 h. Key substances of systemic inflammation were determined (plasma values of TNF‐α, IL‐6, IL‐10, and corticosterone; reactive oxygen species in peritoneal phagocytes), plasma markers of organ function and integrity (AST, ALT, αGST, creatinine, urea), and survival.

Results: Hypothermia reduced the release of IL‐6 (P<0.01). The reductions of plasma levels of TNFα (P=0.07) and IL‐10 (P=0.09) were less clear‐cut. The release of reactive oxygen species diminished (P<0.01). Organ injury was ameliorated, as reflected by decreased levels of AST (P<0.01), αGST (P<0.01), and creatinine (P<0.01). Both groups experienced an almost identical increase of plasma corticosterone. None of the hypothermic rats died, compared to two normothermic.

Conclusion: Moderate hypothermia had an organ protective effect in this model of controlled haemorrhagic shock. This coincided with a significant reduction of the proximal cytokine IL‐6 and reactive oxygen species, which conceivably influenced the outcome.
Spontaneous movements, local reactions and pain on injection of rocuronium
Authors: Mencke T. , Beerhalter U. , Fuchs‐Buder T.
Published: March 2003

Background: We investigated the incidence of withdrawal, local reactions and pain on injection of rocuronium in 120 adult ASA I–II patients undergoing general anaesthesia (group A: 60 male patients, group B: 60 female patients).

Methods: After induction of anaesthesia with propofol and remifentanil, rocuronium 0.6 mg kg−1 was injected in a separate intravenous cannula on the opposite arm. The patient’s response to the injection of rocuronium was graded using a four‐point scale. The appearance of local signs (i.e. erythema, venous sequelae) on the arm where rocuronium had been injected was recorded at the end of the injection as well as 1 h and 24 h after recovery from anaesthesia. Moreover, patients were asked 24 h after recovery from anaesthesia whether they had recall of pain or movements in this arm during induction of anaesthesia.

Results: In 26 of the 120 patients (22%) included, withdrawal reactions after injection of rocuronium were observed. Of these 26 patients, 16 (13%) had severe movements. The overall incidence of withdrawal reactions after rocuronium as well as the incidence of severe reactions was significantly higher in female patients compared to male patients (overall incidence: 18 females (30%) vs. 8 males (13%), P<0.05; severe reaction: 13 females (22%) vs. 3 males (5%), P<0.05). No local reactions were observed and no patient remembered any pain or movements during induction of anaesthesia.

Conclusion: The incidence and the degree of withdrawal reactions in response to the injection of rocuronium were significantly higher in women than in men. This was not associated with adverse clinical consequences for the patient’s outcome.
Assessment of the efficacy of esmolol on the haemodynamic changes induced by laryngoscopy and tracheal intubation: A meta‐analysis
Authors: Figueredo E. , Garcia‐Fuentes E. M.
Published: March 2003

Background: Adrenergic stress response induced by laryngoscopy and tracheal intubation (LTI) appears to be attenuated by esmolol, but its potential clinical benefits have not been fully weighed against possible adverse effects.

Methods: A systematic search up to May 2000 was performed using MEDLINE, EMBASE, LILACS, Cochrane library, manual searching and bibliographies in all languages. All randomised comparisons of esmolol with placebo on the haemodynamic changes elicited by LTI were obtained. Trials were included in the present meta‐analysis if they recorded heart rate (HR), systolic pressure (SBP), mean arterial pressure (MAP) or diastolic pressure (DBP) at three different stages: pre‐induction, immediately prior to intubation, and in the post‐intubation period. Weighted mean differences (WMD) and 95% confidence intervals (CI) of the changes in the haemodynamic variables between treatment and placebo groups were calculated.

Results: Of 72 publications identified, 38 randomised controlled trials containing a total of 2009 patients were finally included. Eleven different regimens and doses of esmolol demonstrated effectiveness in the attenuation of HR and BP after LTI in a dose‐dependent manner. The most effective regimen was a loading dose of 500 μg · kg−1 · min−1 over 4 min followed by continuous infusion dose of 200–300 μg · kg−1 · min−1[WMD: 20.2 bpm (95% CI: 15.6 to 24.7)]. High bolus dose (200 mg) of esmolol produced a considerable decrease in DBP [WMD 10.1 mmHg (95% CI: 7.3 to 12.8)].

Conclusion: Esmolol is effective, in a dose‐dependent manner, in the attenuation of the adrenergic response to LTI. To minimise its adverse effects it should be administered, when considered clinically appropriate, as a continuous infusion regimen.
Evaluation and assessment of cancer pain and cancer pain treatment
Authors: Caraceni A.
Published: March 2003

Evaluation and assessment are the first steps of any strategy for the management of cancer pain, and are fundamental for any clinical research project in this field. Different clinical systems for evaluation and classification of cancer pain syndromes are available and their clinical usefulness should be tested. The measurement of pain intensity is necessary to document and assess the outcome of established and new treatments. Visual analogue scales, verbal and numerical rating scales and some multidimensional tools such as the Brief Pain Inventory and the McGill Pain Questionnaire are helpful in the assessment of cancer pain provided the limitations of their validity are considered. Specific questions arise when these tools are used in long‐term repeated assessments of cancer patients. Assessment and measuring techniques deserve more investigations to optimize standard valid procedures and to enable us to exchange clinical information and produce comparable data in research.
Psychological issues in cancer and non‐cancer conditions
Authors: Bond M. R.
Published: March 2003

The mechanism whereby incoming noxious stimuli result in emotional and behavioural changes is centred within cognitive processes. The mechanism is activated for all forms of pain but variations in the emotions generated and coping styles and strategies adopted occur. They are related to each individual’s appraisal of their pain and the condition giving rise to it – major differences in appraisal relate to the presence or absence of malignancy with its potential threat to life. The psychological treatments of cognitive behavioural therapy have a role in the management of all chronic pain but historically have been employed more in non‐cancer pain conditions than in patients with cancer pain. In the United Kingdom, the facilities for the treatment of pain by cognitive behavioural therapy are very limited and for that reason counselling, long used in aiding cancer patients, is likely to remain the main form of psychological treatment in that group.
Neurosurgical approaches to pain treatment
Authors: Meyerson B. A.
Published: March 2003

In a multidisciplinary approach to the management of chronic pain, neurosurgical methods are an indispensable part of the therapeutic armamentarium. With the exception of percutaneous interventions for trigeminal neuralgia and facet joint syndromes, most ablative pain surgery procedures (neurotomy, rhizotomy, sympathectomy, etc.) have been replaced by neuromodulatory approaches such as electrical stimulation of the central nervous system (CNS). However, cordotomy is still a valuable operation for certain forms of cancer related pains (Pancoast’s syndrome, breakthrough pain) which are relatively resistant to pharmacotherapy. Another example of ablative surgery is the dorsal root entry zone (DREZ) operation, which is generally the only treatment option for pain due to root avulsion and segmental pain in spinal cord injury. Spinal cord stimulation (SCS) has proven to be most useful for the management of pain following peripheral nerve injury (including complex regional pain syndromes) and rhizopathy. For these conditions which are otherwise often therapy resistant, SCS may produce substantial and long‐lasting pain relief in 60–70% of the patients. Considering that such pains are common and the fact that SCS has been shown to be cost‐effective, this treatment is no doubt at present underused. Complications and side‐effects are very rare. SCS has also been found to be useful for pain in peripheral vascular disorders and angina pectoris. In the latter condition the overall results are favorable in about 80% of patients with a significant reduction of the frequency and severity of angina attacks and the need for nitrates. Stimulation of the motor cortex is a novel and promising treatment of central, post‐stroke pain and painful trigeminal neuropathy.
Airway management behaviour, experience and knowledge among Danish anaesthesiologists – room for improvement
Authors: Kristensen M. S. , Møller J.
Published: March 2003

Background: Problems with managing the airways in relation to anaesthesia causes severe morbidity and mortality. A large proportion of these adverse respiratory events is preventable. Still patients continue to die from airway disasters related to anaesthesia, also in Scandinavia. The goal of this study is to identify which efforts are likely to improve this situation.

Methods: A questionnaire asking about experience, behaviour and availability of various items of equipment was mailed to all members of the Danish Society of Anaesthesiologists and were returned anonymously.

Results: More than 65% of respondents have sufficient access to a flexible fibrescope, but still 17% of specialists have no access and the vast majority (>67%) has little (1–10 times) or no experience in its use for awake intubation. A total of 52–70% knew the basic principles of the ASA difficult airway algorithm, but despite this only 25–50% would perform awake intubation if a difficult intubation was expected. More than 20% of respondents had experienced preventable airway management mishaps. In all, 18–46% did not know how to oxygenate via the cricothyroid membrane.

Conclusion: There is room for improvement regarding airway management skills among Danish anaesthesiologists. It is likely that airway management can be improved by: A) Better knowledge of an appropriate plan, algorithm, for airway management. B) Awake intubation used more often. C) More experience in fibreoptic intubation. D) All anaesthesiologists accepting that previous difficult intubation is an indicator of future difficulties. E) All anaesthesiologists knowing, and practising on manikins, how to oxygenate via the cricothyroid membrane. F) Always having a laryngeal mask airway immediately available when inducing anaesthesia.
Comparison of plasma α glutathione S‐transferase concentrations during and after low‐flow sevoflurane or isoflurane anaesthesia
Authors: Higuchi H. , Adachi Y. , Wada H. , Kanno M. , Satoh T.
Published: March 2003

Background: We evaluated the effect of low‐flow sevoflurane anaesthesia, in which compound A is generated, and isoflurane anaesthesia, in which compound A is not generated (n=13 in each group), on hepatocellular integrity using α glutathione S‐transferase (GST). α GST is a more sensitive and specific marker of hepatocellular damage than is aminotransferase activity and correlates better with hepatic histology.

Methods: Sevoflurane or isoflurane were delivered without nitrous oxide with a fresh gas flow of 1 l/min. Concentrations of compound A in the circuit were measured hourly, and plasma α GST concentrations were measured perioperatively.

Results: Mean duration of anaesthesia was 338±92 min in the sevoflurane group and 320±63 min in the isoflurane group. Mean compound A concentration in the sevoflurane group was 28.6±9.0 ppm. There was no significant difference in α GST concentrations between the sevoflurane and isoflurane groups during or after anaesthesia.

Conclusion: These results indicate that low‐flow sevoflurane and isoflurane anaesthesia have the same effect on hepatic function, as assessed by plasma α GST concentrations.
Diabetes attenuates the minimum anaesthetic concentration (MAC) and MAC‐blocking adrenergic response reducing actions of clonidine in rats
Authors: Kita T. , Kagawa K. , Mammoto T. , Takada K. , Hayashi Y. , Mashimo T. , Kishi Y.
Published: March 2003

Background: It is well known that clonidine, an α2 agonist, reduces anaesthetic requirement and attenuates haemodynamic responses against noxious stimuli. However, the diabetic state is known to affect several functions of α2 adrenoceptors. We investigated the effects of streptozotocin (STZ)‐induced diabetes mellitus (DM) on these beneficial actions of clonidine in halothane‐anaesthetized rats.

Methods: The rats were randomly assigned to one of three groups: diabetes (n=24, induced by 50 mg · kg−1 IV STZ), diabetes treated with insulin (n=24), or control (n=24). We evaluated the effects of clonidine on minimum anaesthetic concentration (MAC) and minimum concentration of halothane needed to suppress cardiovascular responses evoked by a noxious stimulus (MAC‐blocking adrenergic responses: MAC‐BAR) in each group. MAC and MAC‐BAR of halothane were determined by the tail clamp method. MAC‐BAR was defined as the MAC which attenuated haemodynamic responses within 10% following the tail clamp.

Results: The diabetic state decreased MAC of halothane by approximately 10%, while MAC‐BAR of halothane had been little affected. In the diabetes group, MAC reducing action of clonidine (30 and 100 μg · kg−1, IV) was completely abolished and MAC‐BAR reducing action of clonidine was partially reduced (30 but not 100 μg · kg−1, IV). Insulin treatment preserved these actions of clonidine.

Conclusion: It is suggested that the diabetic state attenuates the beneficial actions of clonidine and that insulin treatment of diabetes preserves these actions of clonidine.
Continuously infused methylene blue modulates the early cardiopulmonary response to endotoxin in awake sheep
Authors: Evgenov O. V. , Sveinbjørnsson B. , Bjertnaes L. J.
Published: March 2003

Background: In endotoxemia and septic shock, enhanced generation of endogenous nitric oxide (NO) contributes to myocardial depression, hypotension, and derangement of gas exchange. We hypothesized that continuous infusion of methylene blue (MB), an inhibitor of the NO pathway, would counteract these effects in endotoxemic sheep.

Methods: Twenty‐one sheep were anesthetized and instrumented for a chronic study with vascular catheters. On the day of the experiment, 18 conscious animals randomly received either an intravenous injection of MB 10 mg  ·  kg−1 or isotonic saline. Thirty minutes later, sheep received a 20‐min intravenous infusion of Escherichia coli endotoxin 1 μg  ·  kg−1 and either an intravenous infusion of MB 2.5 mg  ·  kg−1  ·  h−1 or isotonic saline, respectively, for 5 h. In addition, 3 animals were exposed to the same dose of MB alone.

Results: MB reduced the early endotoxin‐induced declines in stroke volume, left ventricular stroke work and cardiac indices, and prevented mean arterial pressure from falling. Moreover, MB ameliorated the increases in pulmonary arterial pressure and pulmonary vascular resistance index. In addition, MB reduced the increments in venous admixture and AaPO2, decreased the falls in PaO2, SaO2, and oxygen delivery, and maintained oxygen consumption. MB also prevented the rises in body temperature and plasma nitrites and nitrates, and delayed the elevation of plasma lactate. When given alone to healthy sheep, MB transiently reduced plasma lactate and PaO2, and increased AaPO2.

Conclusion: In ovine endotoxemia, continuously infused MB counteracts the early myocardial dysfunction and derangement of hemodynamics and gas exchange.
Inspiratory pressure–volume curves at different positive end‐expiratory pressure levels in patients with ALI/ARDS
Authors: Nagano O. , Tokioka H. , Ohta Y. , Goto K. , Katayama H. , Hirakawa M.
Published: March 2003

Background: In lung protective strategy, positive end‐expiratory pressure (PEEP) slightly higher than the Pflex (the airway pressure corresponding to the lower inflection point (LIP) on the inspiratory pressure–volume (P‐V) curve measured with ZEEP) is generally recommended. However, this method to determine optimal PEEP lacks a theoretical background and there is no clinical report that investigated how the P‐V relationship would be with such PEEP. Therefore, we measured inspiratory P‐V curves at different PEEP levels to increase our knowledge about the inspiratory P‐V curve with PEEP.

Methods: In eight consecutive patients with ALI/ARDS, inspiratory P‐V curves were repeatedly measured at different PEEP levels by low flow inflation technique and LIP was assessed in all inspiratory P‐V curves. Afterwards, the minimum PEEP level at which LIP was not identifiable (PEEPLIP(−)) was determined and the relationship between Pflex and PEEPLIP(−) was investigated.

Results: P
flex and PEEPLIP(−) could be determined in all patients. Pflex was 9.4±2.0 cmH2O (range: 7 to 12 cmH2O) and PEEPLIP(−) was 7.9±1.6 cmH2O (range: 5 to 10 cmH2O) (mean±SD, P=0.0877). PEEPLIP(−) was lower than the Pflex in five patients, and significantly lower than the Pflex+ 2 cmH2O (P=0.0024).

Conclusion: From the analysis of inspiratory P‐V curves at different PEEP levels, PEEP 2 cmH2O higher than the Pflex may not be necessary to prevent cyclic collapse and reopening of alveoli, at least in some ALI/ARDS patients. Further studies are needed to confirm this preliminary result.
Anaphylactic reactions in anaesthetised patients – four cases of chlorhexidine allergy
Authors: Garvey L. H. , Roed‐Petersen J. , Husum B.
Published: March 2003

Chlorhexidine is widely used all over the world in many different preparations. In Denmark chlorhexidine is the standard skin disinfectant used before surgery or invasive procedures and it is widely used in the general population in mouthwash or for disinfection of minor scratches etc. The potential for developing allergy to chlorhexidine is thus great, especially in surgical patients. We have identified four patients with serious allergic reactions in connection with surgery and general anaesthesia, who on subsequent skin testing tested positive for chlorhexidine. Symptoms appeared 20–40 min into the operation and all four patients required treatment with adrenaline. All four patients had a history of minor symptoms like rashes or faints in connection with previous surgery/invasive procedures. Allergy to chlorhexidine may be more prevalent in surgical patients and cases may have been overlooked due to the nature of reactions and lack of suspicion towards this substance.
Effects of intravenous anesthetics on interleukin (IL)‐6 and IL‐10 production by lipopolysaccharide‐stimulated mononuclear cells from healthy volunteers
Authors: Takaono M. , Yogosawa T. , Okawa‐Takatsuji M. , Aotsuka S.
Published: March 2003

Background: Surgical trauma has been shown to augment the plasma concentrations of proinflammatory cytokines, which are important mediators of host defense mechanisms and the systemic inflammatory response syndrome (SIRS). Recently, it has been shown that certain kinds of surgery provoke not only a proinflammatory response (SIRS) but also a concurrent anti‐inflammatory response. The aim of this study was therefore to examine the effects of intravenous anesthetics on the synthesis of interleukin (IL)‐6 (a proinflammatory cytokine) and IL‐10 (an anti‐inflammatory cytokine) by lipopolysaccharide (LPS)‐stimulated mononuclear cells from healthy volunteers.

Methods: Peripheral blood mononuclear cells (PBMCs) from 17 healthy volunteers, separated by centrifugation on a Ficoll‐Hypaque gradient, were washed and suspended in RPMI containing 10% heat‐inactivated fetal calf serum (FCS). After adding RPMI‐FCS containing various concentrations of intravenous anesthetics (propofol, thiopental, ketamine and midazolam), the PBMCs were incubated overnight in the presence of a submaximal concentration of LPS. The supernatants were collected and their IL‐6 and IL‐10 contents were assayed using enzyme‐linked immunosorbent assay kits.

Results: Propofol inhibited both IL‐6 and IL‐10 production at 0.5 µg/mL, 5 µg/mL and 50 µg/mL. Conversely, thiopental induced IL‐10 production at 2 µg/mL and 20 µg/mL.

Conclusion: Propofol appears to inhibit both IL‐6 and IL‐10 production by LPS‐stimulated PBMCs in vitro. Further study is required to clarify the mechanism of the suppressive effect of propofol.
EMLA® cream prior to digital nerve block for ingrown nail surgery does not reduce pain at injection of anesthetic solution
Authors: Serour F. , Ben‐Yehuda Y. , Boaz M.
Published: March 2003

Background: Needle penetration and local anesthetic infiltration are painful steps of digital ring block. The objective of this study was to evaluate the efficacy of EMLA® cream application prior to digital ring block for surgery for ingrown big toenail.

Methods: We conducted a prospective, double‐blinded, placebo‐controlled, randomized clinical trial with 81 patients (range: 12–75 years, mean ± SD: 30.3 ± 17.5 years), who underwent big toenail surgery. Prior to the digital block, EMLA cream (Group E) or a placebo cream (Group P) was applied. A visual analog scale (VAS) and a verbal rating score (VRS) from 1 to 10, 10 being most severe pain, were used for assessment of pain during the skin needle penetration and during the infiltration of the anesthetic product.

Results: Data of the VAS and of the VRS during the two steps, respectively, show no significant difference in pain rating between the two groups. In Group E, the gender of the patients had a significant effect on pain perception. Male patients reported less pain than female patients, both during the needle skin penetration and during the infiltration step (P < 0.005). In Group P, reported pain did not differ by gender in either step of the procedure.

Conclusions: We found no clinical benefit in using EMLA during digital nerve block. Although the digital nerves are not deeply located in the small subcutaneous space of the digit, topical anesthesia may not reach them. Moreover, swelling due to injection of the anesthetic product in this small space may also amplify the sensation of pain.