bluuebunny/crossref_metadata_2025 huggingface dataset:
Life‐threatening haemorrhage following obturator artery injury during transurethral bladder surgery: a sequel of an unsuccessful obturator nerve block
Authors: Akata T. , Murakami J. , Yoshinaga A.
Published: March 2003

In spite of prior blockade of the obturator nerve with 1% mepivacaine (8 ml) utilizing a nerve stimulator, violent leg jerking was evoked during transurethral electroresection of a bladder tumour approximately 1 h after the blockade in a 68‐year‐old man. The patient became severely hypotensive immediately following the jerking, and a large lower abdominal swelling concurrently developed. The urgent laparotomy indicated that the left obturator artery was severely injured by the resectoscope associated with the bladder perforation, causing acute massive haemorrhage. The patient recovered uneventfully after adequate surgery. Investigation of the literature suggested that both our nerve stimulation technique and anatomical approach were appropriate. It was therefore unlikely that our block resulted in failure because of an inappropriate site for deposition of the anaesthetic. However, consensus does not appear to have been obtained as to the concentration and volume of the anaesthetic necessary for prevention of the obturator nerve stimulation during the transurethral procedures. The concentration and volume of mepivacaine we used might have been too low and/or small, respectively, to profoundly block all the motor neuron fibres of the nerve. Alternatively, stimulation of the obturator nerve might occur because of the presence of some anatomical variant, such as the accessory obturator nerve or its abnormal branching. In conclusion, some uncertainty appears to exist in the effectiveness of the local anaesthetic blockade of the obturator nerve. In order to attain profound blockade of the motor neuron fibres of the obturator nerve and thereby prevent the thigh‐adductor muscle contraction which can lead to life‐threatening situations, we recommend, even with a nerve stimulator, to use a larger volume of a higher concentration of local anaesthetic with a longer duration in the obturator nerve block for the transurethral procedures.
Axillary brachial plexus block with ropivacaine 7.5 mg/ml
Authors: Ræder J. C. , Drøsdahl S. , Klaastad Ø. , Kvalsvik O. , Isaksen B. , Strømskag K. E. , Mowinckel P. , Bergheim R. , Selander D.
Published: March 2003

Background: Ropivacaine is less cardiotoxic than bupivacaine and may be used in higher doses in order to increase the quality of a block. The aim of this study was to compare the efficacy and safety of 40 ml ropivacaine 7.5 mg/ml (300 mg) and 40 ml bupivacaine 5 mg/ml (200 mg) for axillary plexus block.

Methods: One hundred and four adult patients were included in a prospective , double‐blind study. Sensory and motor block were tested for the five main terminal nerves of the arm at 10‐min intervals until start of surgery and every second hour thereafter until full resolution of the block.

Results: The overall evaluation of the block by the surgeon and the anesthesiologist showed a significantly better quality in the ropivacaine patients, regarding both anesthesia and motor block. There were no differences in the time to onset and duration of the block. Except for one patient, who had seizures after an accidental IV injection of ropivacaine, there were no major side effects.

Conclusion: Ropivacaine 7.5 mg/ml, 40 ml, produces axillary plexus block of similar onset and duration but better quality than 40 ml of bupivacaine 5.0 mg/ml.
Ropivacaine in peribulbar block: a comparative study with bupivacaine
Authors: Nociti J. R. , Mateus Serzedo P. S. , Zuccolotto E. B. , Cagnolati C. A. , Machado Nunes A. M.
Published: March 2003

Background: Ropivacaine is a new local anesthetic with alleged lower systemic toxicity and slightly lower potency as compared with bupivacaine. The present study aimed to evaluate the efficacy of ropivacaine in peribulbar block, as compared with that of bupivacaine.

Methods: Eighty patients aged 45–92 years with physical status ASA I, II, or III were randomized to Group R (n=40) or Group B (n=40). Group R received 8.0 ml of 1.0% ropivacaine and Group B received 8.0 ml of 0.75% bupivacaine, both solutions with 50 IU/ml hyaluronidase, to induce peribulbar block according to the double‐injection technique. Decreased ocular motility was the only criterion of successful block.

Results: The percentage of patients with decreased ocular motility showing successful block was higher in Group R 1 and 5 min after injection. A score indicating successful peribulbar block was found in all patients 10 min after injection. While no patient complained of a burning sensation during ropivacaine injection, 22.5% of the patients given bupivacaine reported this symptom.

Conclusion: Both local anesthetics were effective in inducing peribulbar block for intraocular surgery. A tendency was noted to a faster onset of peribulbar block with ropivacaine; nevertheless, both drugs had a high degree of success for this block.
Patients with poor preoperative ejection fraction have a higher plasma response of adrenomedullin in response to open heart surgery
Authors: Amado J. A. , Fidalgo I. , García‐Unzueta M. T. , Montalbán C. , Del Moral I. , Pazos F. , Diago C.
Published: March 2003

Background: Adrenomedullin (AM) is a potent vasodilator peptide. Plasma AM levels are increased in heart diseases and in sepsis. Heart surgery under cardiopulmonary bypass (CPB) induces a systemic inflammatory response.

Methods: We measured plasma AM, cAMP (the second messenger of AM), C‐reactive protein (CRP) and haemodynamic parameters in 29 patients undergoing elective open heart surgery, before, during and after anaesthesia and CPB as well as on the first morning after surgery.

Results: Basal AM levels were higher than normal and correlated with systolic pulmonary pressure and pulmonary capillary pressure, but not with other haemodynamic parameters. AM increased during CPB and remained elevated 24 h after the start of surgery. Plasma cAMP increased only at the end of CPB. CRP was increased only in the last sample. At the end of CPB and at the end of surgery AM levels were higher in patients with basal ejection fraction<40% compared with those with ejection fraction >60% [456±386 vs 252±343 (P<0.03) and 832±781 vs 391±356 pg/ml (P<0.05), respectively].

Conclusion: We conclude that AM, as inflammation‐related cytokines, increases during and after CPB, that cAMP response is unrelated to AM and that AM response is higher in those patients with worse basal ejection fraction.
Factors predicting atracurium reversal time
Authors: Kirkegaard‐Nielsen H. , Severinsen I. K. , Pedersen H. S. , Lindholm P.
Published: March 2003

Background: To identify individual factors and combination of factors predictive of reversal time (defined as time from neostigmine administration to train‐of‐four (TOF) ratio 0.70) from atracurium‐induced neuromuscular block, the present study tested the following variables as possible predictors of reversal time: 1) degree of block at the time of antagonism as quantified by first response to TOF or double‐burst stimulation (DBS); 2) time from last supplemental dose of atracurium to administration of neostigmine (pre‐reversal time); and 3) time from administration of initial atracurium dose to T1 (the magnitude of the first twitch in TOF) recovered to 10% (duration of action of the initial dose of atracurium).

Methods: The study population comprised 83 female patients, ASA physical status 1 or 2, anaesthetized with fentanyl, thiopental, halothane and nitrous oxide. Initial and supplemental doses of atracurium were 0.5 mg · kg−1 and 0.15 mg · kg−1, respectively. Evoked responses to TOF or DBS were recorded mechanomyographically. Neuromuscular block was antagonized with neostigmine, 0.07 mg · kg−1, at varying time intervals (6–50 min) after the final atracurium dose.

Results: Multiple linear regression analyses testing T1, D1 (the magnitude of the first twitch in DBS), pre‐reversal time and duration of action of the initial dose of atracurium, demonstrated that with superficial block, T1 >15%, T1 is the only significant predictor for reversal time. With moderate block, 0< T1 ≤15%, both T1 and duration of action of the initial atracurium dose are significant predictors for reversal time. With profound block, T1=0, duration of action of the initial dose and pre‐reversal time are significant predictors for reversal time.

Conclusion: 1) T1 is a more important predictor for reversal time from atracurium‐induced neuromuscular block than D1; 2) predictors differ with the degree of block: with T1 >15%, T1 is the only significant predictor; with 0< T1 ≤15%, the duration of action of the initial dose and T1 are predictors for reversal time; with T1=0 , the duration of action of the initial dose and pre‐reversal time predict reversal time.
Is total body weight an appropriate predictor for propofol maintenance dose?
Authors: Hirota K. , Ebina T. , Sato T. , Ishihara H. , Matsuki A.
Published: March 2003

Background: Infusion rate of propofol during anaesthesia is usually based on total body weight. In this study, we have determined the relationship between total body weight and plasma propofol levels when the infusion rate was based on total body weight.

Methods: Sixty patients undergoing elective surgery were studied. Anaesthesia was induced with propofol 1 mg  ·  kg−1, ketamine 1 mg  ·  kg−1 and fentanyl 2 μg  ·  kg−1, and maintained with propofol 5 mg  ·  kg−1  ·  h−1, ketamine 0.5–1 mg  ·  kg−1  ·  h−1 and fentanyl 5–15 μg  ·  kg−1. Propofol infusion rate did not change during anaesthesia, and infusion was terminated at the end of surgery. Immediately prior to termination of the propofol infusion, arterial blood (5 ml) was collected to measure plasma level of propofol by a high‐performance liquid chromatography equipped with electrochemical detection.

Results: There was a significant correlation between plasma propofol and total body weight (r=0.646, P<0.001). Plasma propofol concentration also correlated with infusion rate, corrected to lean body mass (r=0.527, P<0.001).

Conclusion: During a fixed infusion rate, plasma propofol concentration may be dependent on total body weight.
Warming of insufflation gas during laparoscopic hysterectomy: effect on body temperature and the autonomic nervous system
Authors: Nelskylä K. , Yli‐Hankala A. , Sjöberg J. , Korhonen I. , Korttila K.
Published: March 2003

Background: Hypothermia is a known side effect of laparoscopic operations. It may increase the sympathetic activity of the autonomic nervous system (ANS), which can be evaluated non‐invasively by heart rate variability (HRV). We tested the hypothesis that warming of the delivered CO2 insufflation gas helps to maintain the normal body temperature.

Methods: Thirty‐seven healthy women undergoing laparoscopic hysterectomy were randomized into heated (37°C, n=18) or unheated (24°C, n=19) gas insufflation groups. Anesthesia was induced with propofol and maintained with sevoflurane in O2‐air. Tympanic (ttymp) temperature was recorded before, during and after the operation. Nasopharyngeal (tnaso) temperature was recorded only during operation. Electrocardiograms were recorded and stored to evaluate changes in HRV. The individual changes in HRV were compared after decibel (dB) transformation.

Results: A median decrease in tympanic temperatures during the operation was 0.7°C in the heated and 0.3°C in the unheated group (P=0.01 between groups), and in nasopharyngeal 0.3°C and 0.1°C (P=0.03), respectively. Preanesthetic tympanic values were reached within 90 min after anesthesia. After dB transformation, HRV high frequency power differed between the groups. It was better preserved in the patients receiving unheated gas.

Conclusion: The heating of insufflation gas does not prevent a decrease in body temperature and is thus unnecessary during laparoscopic hysterectomy.
Changes in stroke volume cause change in cardiac output in neonates and infants when mean airway pressure is altered
Authors: Gullberg N. , Winberg P. , Selldén H.
Published: March 2003

Background: Based on early studies in the lamb, and in spite of more recent studies in humans, it has been the received opinion that neonates and infants can not change their stroke volume significantly, but are mainly dependent on changes in heart rate, to change cardiac output. To further evaluate the relationship between cardiac output and stroke volume during mechanical ventilation of neonates and infants, we have studied the effects on cardiac output and stroke volume by two different ways of changing mean airway pressure.

Methods: In one group, mean airway pressure was decreased by using a patient triggered mode: pressure support ventilation; in the other, mean airway pressure was increased by increasing positive end‐expiratory pressure (PEEP). Changes in cardiac output, heart rate and stroke volume were assessed with the Doppler technique, measuring blood flow velocity in the ascending aorta.

Results: Without a significant change in heart rate, we found a significant increase in cardiac output of +16±2% (P<0.01) with a decrease in mean airway pressure and a decrease in cardiac output of −13±4%, (P<0.02) with an increase in mean airway pressure, depicting a change in stroke volume of +17±2% (P<0.02) and −14±5%, (P<0.01) respectively.

Conclusions: We conclude that neonates and infants are able to regulate cardiac output by changing the stroke volume to a greater extent than presumed, at least when cardiac output is influenced by changes in the mean airway pressure.
Mild hypothermia does not increase blood loss during total hip arthroplasty
Authors: Johansson T. , Lisander B. , Ivarsson I.
Published: March 2003

Background: The effects of mild hypothermia on blood loss are little known.

Methods: Patients, undergoing primary prosthetic hip surgery under spinal anaesthesia, were randomised to the operative procedure, with (n=25) or without (n=25) forced air warming. Core temperature was repeatedly measured from the tympanic membrane. The blood loss was calculated by three different methods; the intraoperative loss was estimated visually. The loss during and after the operation was obtained by determination of lost haemoglobin (the Hb‐method). The blood loss during hospital stay was also calculated from the haemoglobin balance.

Results: Among controls, core temperature decreased by 1.3±0.6°C (mean±SD) and in the warmed patients 0.5±0.4°C (P<0.0001). Preoperative variables and the number of allogeneic units transfused did not differ between the groups. In controls, the blood loss during operation was, with the visual method, 698±314 ml, compared with 665±292 ml in warmed patients. With the Hb‐method, the loss was 662±319 and 657±348 ml, respectively. With this method, the external loss during the entire hospital stay was, in controls, 1066±441 ml and in the warmed group, 1047±413 ml. The balance method yielded 1674±646 ml and 1507±652 ml, respectively. Indices of blood loss did not differ significantly between groups and there was no covariation between those variables and the decrease in core temperature.

Conclusions: Forced air warming did not decrease the blood loss. Methods for determination of blood loss yielded widely differing results.
Ketamine does not inhibit inflammatory responses of cultured human endothelial cells but reduces chemotactic activation of neutrophils
Authors: Zahler S. , Heindl B. , Becker B. F.
Published: March 2003

Background: Ketamine is a widely used general anaesthetic, which has been reported to inhibit neutrophil function and neutrophil‐endothelial interaction. To date, however, it is unknown whether ketamine has any direct effects on endothelial cells with respect to inflammation. Therefore, we investigated the influence of varying concentrations of ketamine (0.5, 1, and 3 μM) on the endothelial expression of cytokines and adhesion molecules with relevance for inflammation.

Methods: Cultured human umbilical vein endothelial cells were stimulated with tumor necrosis factor alpha (TNFα, 2.5 ng/ml) for 4 h in the absence or presence of ketamine. The adhesion molecules ICAM‐1 and E‐selectin on the endothelial cells were measured by flow cytometry. Release of the proinflammatory cytokines IL‐6 and IL‐8 by endothelial cells was quantified by ELISA. The acute effect of ketamine on leukocyte activation by the supernatant of endothelial cells pre‐stimulated with TNFα (4 h) was tested by flow cytometric measurement of CD11b, a leukocyte activation marker, after 15 min of coincubation.

Results: TNFα caused dramatic upregulation of both adhesion molecules (15‐fold and 5‐fold vs. control for ELAM‐1 and ICAM‐1, respectively) and of both cytokines (500‐fold and 1.8‐fold for IL‐6 and IL‐8, respectively). No concentration of ketamine employed in our study had any effect on these inflammatory parameters. However, activation of leukocytes by supernatant of TNFα‐conditioned endothelial cells (70% increase of CD11b) was attenuated by coincubation of the PMN with 0.5 and 5 μM ketamine (47% and 44% increase, respectively).

Conclusion: These data suggest that ketamine exerts its anti‐inflammatory actions primarily via inhibition of leukocyte reactivity. Indeed, no inhibition of endothelial responses was detectable in our study.
Passive expiratory flow‐volume curve is not an accurate method to measure the respiratory time constant in rabbits
Authors: Vialet R. , Monnier A. , Lagier P. , Jammes Y. , Toméi C. , Martin C.
Published: March 2003

Background:: In mechanically ventilated patients, inspiration is forced by an externally applied positive pressure whereas expiration remains passive and depends on the time constant of the total respiratory system (τ), which constitutes an important determinant of mechanical ventilation. The end‐inspiratory occlusion technique is one of the easiest methods to obtain τ values in ventilated patients, especially infants, but its accuracy is not well established. The aim of this study was to compare in anesthetized, paralyzed rabbits τ values given by the end‐inspiratory occlusion technique (τrs) to τ values obtained by references methods for measurements (i.e. the product of static lung compliance by airway resistance: τref) during carbachol‐induced bronchospasm eliciting marked modifications of the respiratory mechanics.

Methods: Comparisons were made in the basal state and after carbachol‐induced bronchoconstriction in seven New Zealand adult rabbits. This procedure resulted in a wide range of expiratory time constants. A pneumotachograph was used to measure expiratory flow and volume before and after end‐inspiratory occlusion. The slope of the flow volume curve gave τrs. Then τrs was compared with τref (which ranged from 0.30 to 1.96 s).

Results: Statistical analysis revealed a weak correlation between the two methods, and a size‐dependent bias of τrs measurements.

Conclusions:: The end‐inspiratory occlusion technique leads to a systemic bias in measurements of respiratory time constant, especially when the resistance of the respiratory system is elevated.
Intraarticular, epidural, and intravenous analgesia after total knee arthroplasty
Authors: Klasen J. A. , Opitz S. A. , Melzer C. , Thiel A. , Hempelmann G.
Published: March 2003

Background: After total knee arthroplasty, patients regularly suffer from severe pain. It is unclear whether epidural or systemic pain therapy is superior in terms of postoperative pain relief, patients’ comfort and side effects. A new therapeutic approach, intraarticular opioids, has been suggested with the detection of opioid receptors in inflamed tissue. This method has proven suitable for clinical use in small operations (e.g. knee arthroscopy). In this study, we compared epidural analgesia and intraarticular application of morphine plus “on‐demand” intravenous analgesia to “on‐demand” intravenous analgesia alone.

Methods: Thirty‐seven patients, scheduled for total knee arthroplasty, were randomly assigned to three treatment groups: in group 1 (EPI) patients received bolus doses of morphine via an epidural catheter; in group 2 (IA) an intraarticular bolus of 1 mg of morphine was applied at the end of the operation with subsequent use of a patient‐controlled analgesia (PCA) pump; group 3 (Control), in which only PCA was provided, served as control for both analgesic procedures. Main outcome measures included visual analogue pain scales, total morphine consumption, and stress hormones.

Results: No statistically significant differences in visual analogue pain scales could be detected between the three groups. Application of intraarticular morphine did not reduce the amount of analgesics required for postoperative analgesia as compared to intravenous analgesia alone. Application of epidural morphine significantly suppressed β‐endorphine release, but did not significantly influence other stress hormones as compared to the control group.

Conclusion: Epidural and intravenous analgesia after total knee arthroplasty are equivalent methods of pain relief. In major orthopaedic procedures, application of intraarticular morphine does not reduce analgesic requirements.
Lateral infraclavicular plexus block vs. axillary block for hand and forearm surgery
Authors: Kapral S. , Jandrasits O. , Schabernig C. , Likar R. , Reddy B. , Mayer N. , Weinstabl C.
Published: March 2003

Background: In the last few years infraclavicular plexus block has become a method of increasing interest. However, this block has been associated with high complication incidences and without advantage in the quality of blockade over the axillary approach. We prospectively studied 40 patients (ASA I–III) undergoing surgery of the forearm and hand, and investigated the performance of the lateral infraclavicular plexus block against an axillary paravascular block to evaluate the success rate as well as the extent and quality of blockade.

Methods: Patients were randomized into two groups: group I (lateral infraclavicular approach; n=20) and group A (axillary approach; n=20). The lateral infraclavicular approach is a technique with the coracoid process (CP) as landmark. Alone the sagittal plane, the needle is inserted until contact with the CP. The needle is then withdrawn 2–3 mm and reinserted directly under the CP, until it contacts the brachial plexus sheath. Plexus blockade was performed using 40 ml of mepivacaine 1%. Quality of sensory and motor block was recorded selectively for each nerve distribution at close intervals for 6 h.

Results: Successful block according to Vester‐Andersen’s criteria was achieved in 100% of group I and 85% of group A. In group I, a pronounced sensory and motor blockade of the musculocutaneous nerve was observed, while patients of group A had a weak block of this nerve. In group I, an additional spectrum of nerves (thoracodorsal, axillary and medial brachial cutaneous nerves) was involved compared to group A. There was no difference among groups in onset and duration of block.

Conclusion: Based on the safe landmark and feasibility of this procedure and the additional spectrum of nerve block achieved, the application of lateral infraclavicular technique has to be reconsidered in clinical practice.
Effects of propofol on isolated human pial arteries
Authors: Wallerstedt S. M. , Reinstrup P. , Uski T. , Bodelsson M.
Published: March 2003

Background: The intravenous anaesthetic propofol has been reported to increase cerebral vascular resistance in vivo. The underlying mechanisms are not fully understood, but may include effects on metabolism and direct effects on the vascular smooth muscle. The present study was designed to evaluate the direct effects of propofol on human pial arteries.

Methods: We investigated the direct effect of propofol (10−6–10−4 M) on isolated human pial arteries at basal tension as well as the influence on contractions induced by 5‐hydroxytryp?ta?mine, prostaglandin F2α, noradrenaline and potassium chloride.

Results: Propofol did not change the basal tension. Propofol at 10−6 and 10−5 M did not affect the concentration‐response curves of any of the contractile agents tested. Propofol at the supraclinical concentration 10−4 M reduced the contractions induced by all contractile agents.

Conclusion: Propofol reduces the tone of human pial arteries in vitro at supraclinical concentrations, but has no effect on the tone at clinically relevant concentrations.
Effects of desflurane on the pig intestinal circulation during hypotension
Authors: Sundeman H. , Åneman A. , Broomé M. , Haney M. , Johansson G. , Häggmark S. , Biber B. , Winsö O.
Published: March 2003

Background: The aim of the present study was to analyze the perfusion pressure dependency for the splanchnic vascular effects of desflurane (DES).

Methods: We measured portal blood flow (QPORT, perivascular ultrasound) and jejunal mucosal perfusion (JMP; laser Doppler) in pentobarbital‐anesthetized pigs (n=10). Experimentally, decreases in mean arterial pressure (MAP) were produced by pericardial infusions of dextran. The protocol included sets of measurements at incremental doses of DES (1, 2, 4 and 6%) prior to and during pericardial infusions.

Results: Although QPORT and JMP decreased significantly during pericardial infusions, DES, irrespective of dose, did not reduce QPORT until MAP had decreased below 65–70 mm Hg. In higher MAP ranges, vasodilation in pre‐portal tissues was powerful enough to maintain QPORT in spite of concurrent decreases in driving arterial pressure, as produced by either DES or pericardial infusion, or by a combination of both. We found no effects of DES on JMP even at very low MAP (about 40 mm Hg during pericardial infusion), indicating that the normal physiological response of the small intestine to redistribute blood flow from deeper to more superficial layers during hypotension was unimpaired by DES.

Conclusions: Our data suggest a wide dose‐tolerability of DES as regards the splanchnic circulation during hypotensive states.
Ultrasonographically guided percutaneous dilatational tracheostomy after anterior cervical spine fixation
Authors: S˘ustić A. , Z˘upan Z˘. , Es˘kinja N. , irlić A. , Bajek G.
Published: March 2003

Patients with anterior cervical spine fixation (ACSF) after acute spinal cord injury often require tracheostomy for prolonged ventilatory support and upper respiratory tract clearance. The authors report two patients with ACSF who underwent a successful ultrasonographically guided percutaneous tracheostomy with dilatation forceps technique. Possible advantages of the ultrasonographically guided method with dilatation forceps in patients with ACSF are discussed.
Nitroglycerin relieves laryngospasm
Authors: Sibai A. N. , Yamout I.
Published: March 2003

Two young healthy non‐asthmatic non‐smoking patients developed partial laryngospasm directly post‐anaesthesia extubation after routine varicocelectomy and perianal abscess drainage operations under general anaesthesia. Nitroglycerin was administered intravenously in a dose of 4 μg/kg for both cases. The laryngospasm was completely relieved within a minute of nitroglycerin administration in both cases and the relief was maintained thereafter. The two cases suggest that nitroglycerin can be effective in the treatment of post‐extubation partial laryngospasm in ASA (class I) patients.
Movement of the endotracheal tube during laparoscopic hernia repair
Authors: Mendonca C. , Baguley I. , Kuipers A. J. , King D. , Lam F. Y.
Published: March 2003

Background: Laparoscopic surgery is not without its problems, and one of the less known is cephalad displacement of the carina and relative movement of the endotracheal tube in the trachea. The aetiology of this is presumably a consequence of both pneumoperitoneum and the Trendelenburg position frequently adopted during laparoscopic surgery.

Method:

We studied 30 patients undergoing laparoscopic hernia repair utilising 10° of Trendelenburg position and an intra‐abdominal inflation pressure of between 12 and 15 mm Hg (mean 13.6 mm Hg). We measured the distance between the tip of the endotracheal tube and the carina using a fibreoptic bronchoscope.

Result:

This distance decreased only slightly, from a mean (SD) of 39.6 (13) mm after intubation, to 38.9 (12.6) mm after adoption of Trendelenburg tilt and pneumoperitoneum. This did not represent a statistically significant change (P=0.09).

Conclusion: We conclude that the endotracheal tube does not routinely migrate towards the carina when laparoscopic hernia repair is performed under these conditions.
Need for a reliable pain evaluation scale in the newborn in Sweden
Authors: Gradin M.
Published: March 2003

Background: A major problem in pain treatment in the newborn is the ability to assess the degree of experienced pain. Several different methods for estimating pain in the newborn have been introduced in recent years. The objectives of this study were to see whether pain scoring was used in Swedish neonatal units, and by which method, and furthermore to observe whether any changes had occurred between 1993 and 1998.

Method:

A questionnaire was distributed to all Swedish neonatal units in 1993 and 1998.

Results: In both 1993 and 1998, 86% of all clinics answered the questionnaire. Two‐thirds of these clinics used some method for estimating pain in the newborn at both times. Eight clinics used a structured method in the latter period compared to one in the earlier period. A higher proportion of units having full intensive care measured pain compared to other units.

Conclusion: The study shows that an unchanging low proportion of neonatal units in Sweden attempt to assess pain. There is a minor increase in the number of departments that use a structured method for pain scoring. Documentation of pain intensity is still inadequate and should be improved.
Pulsatility does not change cerebral oxygenation during cardiopulmonary bypass
Authors: Grubhofer G. , Mares P. , Rajek A. , Müllner T. , Haisjackl M. , Dworschak M. , Lassnigg A.
Published: March 2003

Background: To determine the effect of pulsatility during cardiopulmonary bypass (CPB) on cerebral oxygenation, we measured oxyhaemoglobin (HbO2), deoxyhaemoglobin (Hb) and oxidised cytochrome aa3 (CtO2) with near‐infrared spectroscopy (NIRS) in 14 patients electively scheduled for cardiac surgery.

Methods: Cerebral oxygenation was measured during steady state CPB at a core temperature of 32°C. Non‐pulsatile flow and pulsatile flow were performed for 10 min each.

Results: After 14 min of CPB, HbO2, Hb and CtO2 were significantly below prebypass values. HbO2 and CtO2 did not alter with changing flow patterns. Hb significantly increased both during the period of nonpulsatile (median: −0.7 vs. 0.25 μmol/l; P<0.05) and pulsatile flow (median: 0.25 vs. 0.5 μmol/l; P<0.001). This increase was independent of flow pattern.

Conclusions: Neither oxygenated haemoglobin, nor intracellular oxygenation, represented by CtO2, indicated a beneficial effect of pulsatile perfusion during hypothermic CPB. These results, however, are only valid for short time effects within 10 min before rewarming from CPB and patients without flow‐limiting stenoses of the carotid artery.
PaO2 during anaesthesia and years of smoking predict late postoperative hypoxaemia and complications after upper abdominal surgery in patients without preoperative cardiopulmonary dysfunction
Authors: Wetterslev J. , Hansen E. G. , Kamp‐Jensen M. , Roikjær O. , Kanstrup I. L.
Published: March 2003

Background: The incidence of late postoperative hypoxaemia and complications after upper abdominal surgery is 20–50% among cardiopulmonary healthy patients. Atelectasis development during anaesthesia and surgery is the main hypothesis to explain postoperative hypoxaemia. This study tested the predictive value of PaO2<19 kPa during combined general and thoracic epidural anaesthesia and the preoperative functional residual capacity (FRC) reduction in the 30° head tilt‐down position for the development of late prolonged postoperative hypoxaemia, PaO2<8.5 kPa for a minimum of 3 out of 4 days, and other complications.

Methods: Forty patients without cardiopulmonary morbidity, assessed by ECG, spirometry, FRC and diffusion capacity preoperatively, underwent upper abdominal surgery. PaO2 during anaesthesia and preoperative FRC reduction were compared to known risk factors for the development of hypoxaemia and complications: age, pack‐years of smoking and duration of operation. The effect of optimizing pulmonary compliance with peroperative positive end‐expiratory pressure (PEEP) on postoperative hypoxaemia and complications was evaluated in a blinded and randomized manner.

Results: Late prolonged postoperative hypoxaemia and other complications were found in 37% and 38% of the patients, respectively. Patients with PaO2>19 kPa during anaesthesia with FIO2=0.33 exhibited a risk, irrespective of PEEP status, of suffering late prolonged hypoxaemia of 0% (0;23) and patients with PaO2<19 kPa a risk of 52% (32;71), P<0.005. Having smoked more than 20 pack‐years was associated with a 47% (19;75) higher incidence of postoperative complications than having smoked less than 20 pack‐years, P<0.006.

Conclusions: PaO2 during anaesthesia and smoked pack‐years provide new tools evaluating patients undergoing upper abdominal surgery in order to predict the patients who develop late postoperative hypoxaemia and complications.
Dysregulation of immune response following neurosurgical operations
Authors: Sablotzki A. , Ebel H. , Mühling J. , Dehne M. G. , Nopens H. , Giesselmann H. , Hempelmann G.
Published: March 2003

Background: Postoperative infections are common and potentially fatal complications in neurosurgical intensive care medicine. An impairment of immune function has been described after central nervous system surgery and in patients harboring malignant brain tumors. The aim of our study was to investigate whether differences in cell‐mediated immunity can be found in patients undergoing craniotomy for surgery of glioblastoma or clipping of an intracerebral aneurysm.

Methods: In order to determine the influence of the underlying disease on the immune system, we measured changes in cytokine concentrations (IL‐6, IL‐10, TGF‐beta1) and lymphocyte‐subsets (CD3+, CD3+HLA‐DR+, CD4+, CD8+, CD19+, and CD16+56+) in 8 patients with glioblastoma and in 8 patients with an intracerebral aneurysm before, during and after the neurosurgical procedure.

Results: In the comparison of glioblastoma and aneurysm patients, we could show that IL‐6 plasma levels were pre‐ and intraoperatively higher in the aneurysm‐group (P<0.05), and the plasma concentrations of IL‐10 and TGF‐β were significantly elevated in the glioma‐group. The lymphocyte‐subsets showed a significantly lower percentage of NK‐cells and activated T‐cells in the glioma‐group.

Conclusion: Our results document a significant dysregulation of immune response in glioma patients. This may be induced by elevated plasma concentrations of immunoinhibiting cytokines IL‐10 and transforming growth factor‐beta 1.
Age‐related modifications of effects of ketamine and propofol on rat hippocampal acetylcholine release studied by in vivo brain microdialysis
Authors: Wang Y. , Kikuchi T. , Sakai M. , Wu J. L. , Sato K. , Okumura F.
Published: March 2003

Background: We sometimes encounter impairment of learning and memory after general anesthesia in elderly patients. The aim of this study was to examine age‐related modifications of the effects of ketamine and propofol on rat hippocampal acetylcholine (ACh) release because hippocampal cholinergic neurons are supposed to be involved in learning and memory.

Methods: The experiments were performed on male Wistar young rats (2 months old) and old rats (18 months old), using in vivo brain microdialysis technique under freely moving condition. After initial sampling of three collections, test drugs were administered. The ACh release was determined by the HPLC‐ECD method.

Results: In old rats, the hippocampal basal ACh release was significantly lower than in young rats. Ketamine (25 and 50 mg kg−1 i.p.) increased and propofol (25 and 50 mg kg−1 i.p.) decreased the hippocampal ACh release in both young and old rats. Furthermore, ketamine 50 mg kg−1 i.p. (anesthetic dose) produced facilitatory effects on the hippocampal ACh release in young rats (193% of the basal release), while in old rats the same dose of ketamine i.p. produced more pronounced facilitatory effects on the hippocampal ACh release (317% of the basal release). On the other hand, propofol 50 mg kg−1 i.p. (anesthetic dose) produced inhibitory effects on the hippocampal ACh release in young rats (56% of control) and in old rats (77% of control). Although the maximal inhibitory peak effects of propofol 50 mg kg−1 i.p. did not differ significantly between young rats and old rats, decrease of the hippocampal ACh release in old rats persisted longer than in young rats.

Conclusion: Ketamine produced more pronounced facilitatory effects on the hippocampal ACh release in old rats, as compared with young rats. On the other hand, propofol has inhibitory effects on the hippocampal ACh release in young and old rats. The aging process may suppress the ability to recover from the inhibitory anesthetic state induced by propofol.
Efficacy and safety of premedication with oral ketamine for day‐case adenoidectomy compared with rectal diazepam/diclofenac and EMLA®
Authors: Filatov S. M. , Baer G. A. , Rorarius M. G. F. , Oikkonen M.
Published: March 2003

Background: Because of its pain‐attenuating and sedative properties oral ketamine has been used as premedication in children and adults. We wanted to compare in children scheduled for adenoidectomy safety and efficacy of oral ketamine with a premedication that causes similar preoperative sedation and relief of pain at the venepuncture site. We also evaluated the effect of i.v. glycopyrrolate added to these combinations.

Methods: One hundred children between 10 and 15 kg of body weight scheduled for day‐case adenoidectomy were randomly assigned to one of four groups: groups DG and DS received diclofenac 12.5 mg and diazepam 0.5 mg/kg rectally, EMLA® cream at the venepuncture site, and placebo orally; groups KG and KS received ketamine 6.0 mg/kg orally, placebo cream at the puncture site, and placebo rectally; additionally, groups DG and KG received glycopyrrolate 5 μg/kg, and groups DS and KS received placebo intravenously. We recorded perioperatively scores (open scale 1–9) for stridor, sedation, bleeding, nausea, pain, heart rate, the need for analgesics and registered psychotomimesis and well‐being at home.

Results: The children of the K‐groups became more tearful during separation from their parents (P=0.0072). No other differences were found between the ketamine and diazepam/diclofenac groups before and after premedication until induction of anaesthesia. Oral ketamine produced unpleasant psychotomimesis in four out of 59 children. During the first 10 min postoperatively, the score for stridor was significantly higher in group KS than in the D‐groups; stridor scores ≥6 were seen in one child of the D‐groups (DS) and in six children of the K‐groups (n.s.), of whom three developed laryngospasm (one reintubation). Glycopyrrolate diminished salivation in all groups, but had no effect on stridor scores. Additionally, glycopyrrolate delayed the onset of eating at home.

Conclusion: Premedication with racemic oral ketamine 6 mg/kg does not seem to be suitable for upper airway procedures. Addition of i.v. glycopyrrolate before the induction of anaesthesia significantly reduced the scores for salivation.
Auditory evoked responses and learning and awareness during general anesthesia
Authors: Ghoneim M. M. , Block R. I. , Dhanaraj V. J. , Todd M. M. , Choi W. W. , Brown C. K.
Published: March 2003

Background: There is a major distinction between conscious and unconscious learning. Monitoring the mid‐latency auditory evoked responses (AER) has been proposed as a measure to ascertain the adequacy of the hypnotic state during surgery. In the present study, we investigated the presence of explicit and implicit memories after anesthesia and examined the relationships of such memories to the AER.

Methods: We studied 180 patients scheduled for elective surgical procedures. After a thiopental induction, one of four anesthetics were studied: Opioid bolus: 7.5 μg · kg−1 fentanyl, 70% N2O, with 2.5 μg · kg−1 supplements as needed (n=100); Opioid infusion: Alfentanil 50 μg · kg−1 bolus, 1–1.5 μg · kg−1 · min−1 infusion, 70% N2O (n=40); Isoflurane 0.3%: Fentanyl 1 μg · kg−1, 70% N2O, isoflurane 0.3% expired (n=16); Isoflurane 0.7%: Fentanyl 1 μg · kg−1, 70% N2O, isoflurane 0.7% expired (n=23). AER were recorded before anesthesia, 5 min after surgical incision and then every 30 min until the end of surgery. A tape of either the story of the “Three Little Pigs” or the “Wizard of Oz” was played continuously between the recordings. Explicit memory was assessed postoperatively by tests of recall and recognition, and implicit memory was assessed by the frequency of story‐related free associations to target words from the stories, which were solicited twice during a structured interview.

Results: Six patients showed explicit recall of intraoperative events: All received the opioid bolus regimen. About 7% of patients reported dreaming during anesthesia. The incidence of picking the correct story that had been presented during anesthesia averaged 49%, i.e., very close to chance level. Overall, priming occurred only at the second association tests for the opioid bolus regimen, for which the frequency of an association to the presented story among those not giving an association to the control story was 26%, which was double the frequency (13%) of an association to the control story among those not giving an association to the presented story. This was significant by McNemar's test, P=0.02. There were significant associations between awareness, priming and AER, e.g., recall was associated with higher Nb amplitudes during anesthesia and priming was associated with shorter wave latencies.

Conclusions: The incidence of awareness in patients anesthetized with nitrous oxide and bolus supplementation was 6%. Thus, this anesthetic technique did not reduce the risk of awareness compared with the use of nitrous oxide alone. Implicit memory occurred during nitrous oxide and bolus supplementation. Recording AER during anesthesia may help to predict awareness and implicit memory, particularly the former. The short contents of most of the dreams which were recalled could hamper future studies in this area.
Influence of acute normovolaemic haemodilution on the dose‐response and time‐course of action of atracuriumNote
Authors: Xue F. S. , Liao X. , Liu J. H. , Zhang Y. M. , An G. , Luo L. K.
Published: March 2003

Background: Acute normovolaemic haemodilution is a common method to save and avoid homologous blood transfusion during surgery. The aim of this study was to evaluate the influence of acute isovolaemic haemodilution on the dose‐response and time‐course of action of atracurium.

Methods: We studied 25 patients undergoing acute isovolaemic haemodilution during surgery and 25 patients not receiving haemodilution as a control group. All patients were ASA grade I and aged 18–54 yr. The haemodilution patients underwent major elective plastic surgery with an anticipated surgical blood loss of more than 600 ml, and the control patients underwent elective superficial plastic surgery with an anticipated surgical blood loss of less than 200 ml. Anaesthesia was induced with thiopental 4–6 mg/kg and fentanyl 2–4 μg/kg i.v., and maintained with 60% nitrous oxide in oxygen. After stabilization of anaesthesia, acute isovolaemic haemodilution in the haemodilution group was achieved by drainage of venous blood and an i.v. infusion of lactated Ringer's solution, and 6% dextran, during which haematocrit and haemoglobin decreased from 45.1% to 25.8% and from 147.2 g/l to 91.2 g/l, respectively. When anaesthesia was stable in the control group and haemodilution was completed in the haemodilution group, neuromuscular function was assessed by measuring with accelerography the response of the adductor pollicis muscle to supramaximal train‐of‐four (TOF) stimuli every 12 s to the ulnar nerve at the wrist via surface electrodes. The dose‐response relationships of atracurium in the two groups were determined by the cumulative dose‐response technique.

Results: The results showed that during haemodilution, the dose‐response curve of atracurium was shifted to the left in a parallel fashion and the potency of atracurium was increased. In patients undergoing haemodilution, ED50, ED90 and ED95 of atracurium were decreased by 25–33%, and duration of action was increased by 21–48% following administration of the same dose (mg/kg), as compared with patients not undergoing haemodilution.

Conclusion: We concluded that the patients undergoing acute isovolaemic haemodilution were about 30% more sensitive to neuromuscular blockade of atracurium and had a longer duration after administration of the same dose (μg/kg) than the control patients. Care must be taken with this problem when atracurium is used as a muscle relaxant during acute haemodilution.
Retracted: Composition of the editorial/advisory boards of major English‐language anesthesia/critical care journals
Authors: Boldt J. , Maleck W.
Published: March 2003

Background: Publications represent a central part of the research process. An analysis of who is responsible for acceptance of publications in major English‐language anesthesia/critical care medicine journals was carried out.

Methods: All English‐language journals listed in the SCI® Journal Citation Reports 1997 under the subheadings Anesthesiology (n=18) and Emergency Medicine & Critical Care (n=16) were analysed with regard to the editorship and the membership of advisory boards listed in the 1998 issues of the journals. The two groups were analysed separately with regard to their country of origin.

Results: In the Anesthesiology section, 140 persons were listed as editors and 423 persons were identified as members of the advisory boards. Editors came from 14 different countries, with editors from the USA representing the majority (n=83; 59% of all editors, followed by the UK: n=24; 15% of all editors). Editors from other countries represent only a minority (n=33; 24% of all editors). The advisory boards came from 30 countries and were also dominated by the USA (n=220; 52% of all persons from the advisory boards). In the Emergency Medicine & Critical Care section 159 persons were listed as editors, of whom 119 originated from the USA (75% of all editors). Of the 835 persons listed in the advisory boards, 72% came from the USA, with 37 other countries sharing the remainder (second, UK: 8%; third, Canada: 2.5%).

Conclusion: Most editors/editorial board members of important Anesthesiology, Emergency and Critical Care journals came from the USA. Other countries play a significantly less influential role even in journals which are characterised as ‘International Journals’.