bluuebunny/crossref_metadata_2025 huggingface dataset:
The detection of carbon dioxide embolism during laparoscopy in pigs: a comparison of transesophageal Doppler and end‐tidal carbon dioxide monitoring
Authors: MANN C. , BOCCARA G. , FABRE J. M. , GREW V. , COLSON P.
Published: January 2009

Background:The aim of the study was to compare the value of transesophageal Doppler and end‐tidal carbon dioxide monitoring to detect venous carbon dioxide embolism in pigs during laparoscopic cholecystectomy.

Method:Ten pigs were anesthetized under constant ventilation, and instrumented for laparoscopic cholecystectomy. CO2 pneumoperitoneum was performed at 15 mmHg and then, successive increased intravenous gas boluses of 0.1 to 4 ml/ kg injectedthrough the femoral vein using a 55‐mm long catheter. The responses indicative of embolism were defined as: 1) a change in Doppler tone placed facing the junction of the right atrium and inferior vena cava; 2)

Results:Doppler was more sensitive in detecting 0.1, 0.2 and 0.4 ml/mg of CO2 embolism than end‐tidal CO2 (P <0.05). Over 0.4 ml/mg no differences in sensitivity were found but the Doppler signal modifications occurred earlier than the changes in end‐tidal CO2. Moreover, these changes always consisted of a reduction of the value.

Conclusions: During laparoscopic cholecystectomy in pigs, transesophageal Doppler was a highly sensitive monitor which provided an earlier detection of CO2 embolism and at lower doses than end‐tidal CO2 monitoring.
Pulmonary clearance of 99m Tc‐DTPA in experimental surfactant dysfunction treated with surfactant instillation
Authors: NILSSON K. , JOHN J. , LACHMANN B. , ROBERTSON B. , WOLLMER P.
Published: January 2009

Background: Breakdown of the alveolo‐capillary barrier is a characteristic feature of respiratory distress syndrome. Restoration of alveolo‐capillary barrier function may be an important aspect of surfactant raplacement therapy. We examined the effect of surfactant instillation on alveolo‐capillary barrier function in an experimental model of surfactant dysfunction by measuring pulmonary clearance of 99mTc‐DTPA.

Methods: Nineteen rabbits were tracheotomized and mechanically ventilated. Surfactant dysfunction was induced by administration of a synthetic detergent in aerosol form. Detergent was given to 13 rabbits; seven rabbits were then treated with instillation of natural surfactant, whereas six rabbits received saline. Six rabbits were used as untreated controls. An aerosol of 99mTc‐DTPA was administered to all animals and the pulmonary clearance was measured with a gamma camera.

Results: 99mTc‐DTPA cleared from the lungs with a half‐life of 71±22 min in the control animals, 21.4±7.4 min in the sur factant‐treated animals and 5.8±1.5 min in the saline‐treated animals. The difference in half‐life between groups was highly significant (P <0.001). There was no change in arterial oxygen‐ation or compliance in controls or in animals treated with saline. In animals treated with surfactant, a small transient reduction in arterial oxygen tension and a more long‐standing reduction in compliance were observed.

Conclusions: Surfactant treatment thus significantly attenuated the effect of detergent treatment but did not restore alveolo‐capillary transfer of 99mTc‐DTPAto normal.
The effect of cortisol suppression on interleukin‐6 and white blood cell responses to surgery
Authors: JAMESON P. , DESBOROUGH J. P. , BRYANT A. E. , HALL G. M.
Published: January 2009

Background:The endocrine and immune changes associated with surgery are well documented, but the interaction between them has not been fully evaluated. Cortisol production during surgery can be suppressed by etomidate and we have used this to investigate the relationshp between the cortisol response and immune changes in the perioperative period.

Methods: We have measured the cortisol, interleukin‐6 and white cell responses to elective abdominal hysterectomy in 8 healthy female patients, who received etomidate 0.3 mg kg‐1 for induction of anaesthesia. A control group of 8 subjects received thiopentone. Both groups of patients received vecuro‐nium and fentanyl 2 yg kg‐1 and anaesthesia was maintained with nitrous oxide in oxygen and isoflurane 0.5‐1.0%. Venous blood samples were collected before and during surgery and up to 24 h in the postoperative period.

Results: Serum interleukin‐6 values were significantly greater at 6 and 12 h (P <0.05) in those patients who received etomidate. Inhibition of the serum cortisol response to surgery in the etomidate group was also associated with less marked lymphopenia at 4 h (P <0.05). There was no significant difference in neutrophil granulocyte counts between the two groups.

Conclusions: In conclusion, endogenous corticosteroids modulate the interleukin‐6 response to surgery.
Pharmacokinetic comparison of intravenous and intranasal administration of oxycodone
Authors: TAKALA A. , KAASALAINEN V. , SEPPÄLÄ T. , KALSO E. , OLKKOLA K. T.
Published: January 2009

Background:For patients with chronic pain, treatment with oral analgesics is considered most convenient and feasible. Sometimes, however, the oral route cannot be used because of difficulties with swallowing, nausea, vomiting and gastrointestinal obstruction. To investigate the applicability of the nasal route for the administration of oxycodone, we studied the intravenous and intranasal pharmacokinetics of oxycodone in healthy volunteers.

Methods: Ten healthy volunteers (3 males and 7 females) were given either an intravenous bolus of oxycodone hydro‐chloride 0.05mg/kg or nasal sprays of oxycodone hydrochlo‐ride 0.lmg/kg in a cross‐over manner. Blood was sampled and subjective effects and side effects were recorded for 10 h.

Results: After intravenous administration of oxycodone, the plasma clearance of oxycodone was 0.83±0.33 l/min (mean ±SD) and the volume of distribution at steady‐state 2.02±1.47 1/kg and the terminal elimination half‐life 157±47 min. After intranasal administration, peak plasma concentration of oxycodone was 13±6ng/ ml and it was reached in the median time of 25 min. The intranasal bioavailability of oxycodone was 0.46±l.34. No clinically significant changes in blood pressure or heart rate were observed but all subjects experienced somnolence after both modes of administration.

Conclusions: The results of this study show that oxycodone is rapidly and rather effectively absorbed from the nasal mucosa but the interindividual differences are large. The intranasal route may in some cases be an attractive alternative to oral or parenteral administration of opioid analgesics. However, because of large interindividual differences, it is prudent to titrate the dose of intranasal oxycodone individually.
Anesthetic quality during cesarean section following subarachnoid or epidural administration of bupivacaine with or without fentanyl
Authors: OLOFSSON Ch. , EKBLOM A. , SKÖLDEFORS E. , WÅGLUND B. , IRESTEDT L.
Published: January 2009

Background: It is often assumed that subarachnoid administration of local anesthetics produces a more profound blockade than epidural anesthesia. Furthermore, the addition of fentanyl has been reported to increase preferentially intraoperative analgesia. In the present study we set out to study these two issues in a randomized and controlled study with respect to perceived pain and discomfort during surgery and postoperative pain.

Methods: In the present study, 100 parturients subjected to elective cesarean section, 34 nullipara and 66 multipara, received one out of four combinations of the local anesthetic bupivacaine and the opioid fentanyl; group A ‐ bupivacaine 12.5 mg+10 μg fentanyl subarachnoidally, group B ‐ bupivacaine 12.5 mg+saline subarachnoidally, group C ‐ bupivacaine 100 mg+100 μg fentanyl epidurally, group D ‐ bupivacaine 100 mg+saline epidurally; N=25 in each group. Pain intensity and discomfort during surgery was assessed with a visual analogue scale (VAS). Postoperative pain intensity and need for analgesics postoperatively, ketobemidone, was registered for 24 h following surgery.

Results: Intraoperative pain intensity and discomfort did not differ significantly between parturients in any of the four groups. Postoperative pain was significantly more intense in parturients receiving local anesthetics subarachnoidally as compared to the epidural groups during the first 6‐h period. This difference was also reflected in a significantly increased consumption of analgesics during this period. No significant differences between the groups were observed with regard to hemo‐dynamics (blood pressure), respiration (oxygen saturation) or other effects such as nausea or itching. All neonates had normal Apgar and neonatal adaptive capacity scores (NACS).

Conclusion: We conclude that subarachnoidal (12.5 mg) and epidural (100 mg) injections with bupivacaine both produced adequate anesthetic quality in women undergoing elective cesarean section. The addition of fentanyl (10 μg subarachnoidally or 100 μg epidurally) did not significantly improve the quality of these already profound blockades.
Assessment of postoperative pain: impact of clinical experience and professional role
Authors: SJÖTRÖM B. , HALJAMÄE H. , DAHLGREN L.‐O. , LINDSTRÖM B.
Published: January 2009

Background: Unrelieved postoperative pain is still reported to be a rather common clinical problem which may be related to inadequate routines for pain assessment. Therefore, the aim of the study was to describe strategies used by experienced and less experienced nurses and physicians in their assessment of postoperative pain and to relate different approaches, clinical experience, and professional role to the accuracy of the pain ratings.

Methods: Data collection was based on repeated interviews with nurses (n=30) and physicians (n=30) in connection with clinical pain assessments (n=180) including VASscoring

Results: Commonly used strategies in the pain assessment were: ‐ how the patient looks, ‐ what the patient says, ‐ the manner of talking, and ‐ past experience of similar circumstances. The mean VAS‐score given by the patients (6.1±21.1) was significantly (P<0.001) higher than that rated by the staff members (4.9±21.2). Nurses as well as physicians overestimated low and underestimated high levels of pain indicated by the patients. The accuracy of the ratings by nurses, especially by more experienced ones (≤10 years in nursing), was found to be less precise than that of physicians. The pain assessment of these very experienced nurses was characterized by a systematic underestimation.

Conclusions: The present study emphasizes a need for definition of more precise strategies for clinical postoperative pain assessment which better take into consideration the pain experiences and needs of individual patients
Perioperative respiratory events in smokers and nonsmokers undergoing general anaesthesia
Authors: SCHWILK B. , BOTHNER U. , SCHRAAC S. , GEORGIEFF M.
Published: January 2009

Background: The prevalence of respiratory diseases in smokers and nonsmokers and the incidence of perioperative respiratory events (PREs) were investigated for patients undergoing general anaesthesia. The aim was to quantify well‐known problems and to identify possible new associations between smoking and PREs.

Methods: From July 1992 to December 1994, risk factors, demographic data, and PREs were documented by an automatically readable anaesthetic record (ARAR). PREs were used as defined by the German Society of Anaesthesiology and Intensive Care.

Results: Of 26 961 subsequent anaesthesias in adults, 7122 (26.4%) were performed in smokers with a prevalence of chronic bronchitis of 23.3% (4.8% in nonsmokers). 1573 PREs occurred in 1397 (5.2%) of all anaesthetics. 459 events concerned intubation problems and problems in technical airway management. 1114 specific respiratory events (SPREs) like re‐intubation, laryngospasm, bronchospasm, aspiration, hy‐poventilation/hypoxaemia and others had a total incidence of 5.5% in smokers and 3.1% in nonsmokers. The relative risk (RR) of SPREs was 1.8 in all smokers, 2.3 in young (16–39 years) smokers, and 6.3 in obese young smokers. The RR of perioperative bronchospasm was 25.7 in young smokers with chronic bronchitis.

Conclusion: The impact of smoking on perioperative respiratory problems should make anaesthetists take this widespread preoperative condition seriously, particularly in young adults. The presented method of incident reporting (based on a national classification) could contribute to future research in anaesthetic epidemiology.
The claims of compensation for awareness with recall during general anaesthesia in Finland
Authors: RANTA S. , RANTA V. , AROMAA U.
Published: January 2009

Background: Awareness during anaesthesia has been estimated to occur in 0.2%‐0.4% of patients undergoing general surgery. In Finland, according to the Patient Injury Act, compensation is paid for an injury caused by medical treatment. We have analysed the claims for compensation involving awareness under anaesthesia filed between May, 1987 and December, 1993.

Methods: Original claims, hospital notes, and expert advisor's comments as well as the comments of the anaesthesiologist in charge of the anaesthesia, and decisions of the Patient Injury Association, were reviewed.

Results: A total of 23 363 claims of patient injury were made during the study period. Of these, 391 considered anaesthetic treatments, and there were four cases of awareness with recall.

Conclusion: Claims of compensation for awareness during anaesthesia were surprisingly few, possible reasons of which are discussed. Compensations paid were low in comparison with some other countries.
Effect of esmolol on the heart rate, arterial pressure and electrocardiographic changes during laryngomicroscopy
Authors: KORPINEN R. , SIMOLA M. , SAARNIVAARA L.
Published: January 2009

Background: Laryngomicroscopy causes considerable haemo‐dynamic and ECG changes and therefore requires high doses of anaesthetic agents, which prolong recovery. In this double‐blind randomized work, we studied the effect of esmolol, a short‐acting beta‐adrenergic receptor‐blocking agent, on haemodyn‐amic and ECG changes during laryngomicroscopy under thio‐pental‐alfentanil‐isoflurane‐suxamethonium anaesthesia.

Methods: Forty ASA class I‐II patients (mean age 43±11 yr) were allocated to receive either esmolol 1 mg·kg‐1+200 μg·kg‐1· min‐1 (the esmolol group) or saline (the control group). Heart rate and arterial pressure were measured non‐invasively and ECG was analyzed with the aid of a microcomputer. Comparisons between the groups were performed using two‐way analysis of variance with repeated measures and the Student's t‐test.

Results: In the presence of esmolol, neither the heart rate nor the QTc interval of the ECG increased significantly when com pared with the baseline values, with the exception that the QTc interval was increased after intubation. The increase in arterial pressure after insertion of the operating laryngoscope was not prevented in esmolol‐treated patients. No cardiac arrhythmias occurred in either of the groups.

Conclusions: On the basis of the present study, esmolol‐bolus +infusion during alfentanil‐isoflurane anaesthesia in healthy, middle‐aged patients is a useful treatment in circumstances where an increase of the heart rate, prolongation of the QTc interval and cardiac arrhythmias should be avoided.
Different effects of halothane, isoflurane and sevoflurane on sarcoplasmic reticulum of vascular smooth muscle in dog mesenteric artery
Authors: YAMAMOTO M. , HATANO Y. , KAKUYAMA M. , NAKAMURA K. , TACHIBANA T. , MAEDA H. , MORI K.
Published: January 2009

Background:The direct effect of halothane on vascular smooth muscle is mediated in part via its effects on the sarcoplasmic reticulum (SR). Little information is available concerning the effects of other volatile anesthetics including isoflurane and sevoflurane, whose vascular effects differ from those of halothane. The aim of the present study was to compare the effects of halothane, isoflurane and sevoflurane on the SR by testing the contraction induced by caffeine in vascular smooth muscle.

Methods:Rings without endothelium from isolated canine mesenteric artery were mounted in physiological saline solution (PSS) for isometric tension recording. After complete depletion of Ca2+from the SR by adding 35 mM caffeine, the rings were exposed to normal Ca2+containing PSS (Ca2+loading), to Ca2+‐free PSS for 10 min, and then to 15 mM caffeine to induce contraction. Anesthetics were administered during Ca2+loading, the Ca2+‐free phase and simultaneously with caffeine administration.

Results:Halothane (0.5‐2%) attenuated the caffeine‐induced contraction of canine mesenteric artery when administered during Ca2+loading in the SR (P<0.001), whereas isoflurane and sevoflurane (1–4%) failed to affect the contraction. When given simultaneously with caffeine, halothane (1–2%) potentiated the caffeine‐induced contraction (P<0.05), but isoflurane and sevoflurane had no effect. When given before caffeine administration, halothane (0.5‐2%), isoflurane (24%) and sevoflurane (4%) all potentiated the caffeine‐induced contraction (P<0.05).

Conclusion:It has been shown that halothane not only potentiates caffeine‐ induced Ca2+release from the SR, but also induces contraction by releasing Ca2+from the SR. We conclude that halothane decreases Ca2+accumulation in the SR while exerting facilitative and additive effects on caffeine‐induced Ca2+release from the SR when applied before caffeine administration and simultaneously with caffeine, respectively, whereas isoflurane and sevoflurane lack both the ability to decrease Ca2+accumulation and an additive effect on caffeine‐induced Ca2+release from the SR, but are able to facilitate Ca2+release by caffeine.
Preoperative glutamine loading does not prevent endotoxemia in cardiac surgery
Authors: SUOJARANTA‐YLINEN R. , RUOKONEN E. , PULKKI K. , MERTSOLA J. , TAKALA J.
Published: January 2009

Background: The presence of endotoxemia is relatively common in cardiac surgery patients and it may modify the metabolic and hemodynamic responses peri‐ and postoperatively. Impaired gut fuel metabolism may contribute to the disturbed function and deterioration of the intestinal mucosal barrier and the development of bacterial translocation and endotoxemia. Glutamine may protect the gut mucosal barrier during marginal or insufficient perfusion.

Methods: We studied the effects of glutamine supplementation on endotoxemia and blood levels of tumor necrosis factor (TNF) during and after extracorporeal circulation (ECC) and the effects of endotoxemia on systemic and regional (splanchnic and leg) hemodynamics and metabolism after cardiac surgery. Nineteen elective coronary bypass patients were randomly assigned to receive preoperatively for 12 h either an infusion of glucose and a balanced amino acid solution (AA‐group) or a solution containing 1/5 of total nitrogen as alanyl‐glutamine (ALAGLN‐group).

Results: Glutamine and amino acid loading before ECC did not protect from peri‐ or postoperative endotoxemia. Endotoxemia was detected in 5 vs. 7 of patients during ECC and 6 vs. 5 of patients postoperatively in the ALAGLN‐group vs. AA‐group, respectively. More than half of the patients at every measurement had an increased level of TNF. There was no consistent difference between the arterial and hepatic vein endotoxin‐ or TNF‐concentrations. Endotoxemia did not modify systemic or regional hemodynamics and metabolism after cardiac operation

Conclusion: Glutamine did not prevent endotoxemia during or after cardiac surgery. An increased level of TNF was common and observed also in some patients without endotoxemia. Endotoxemia did not mode regional or whole‐body metabolic patterns or hemodynamics.
Effects of dopamine, dopexamine and dobutamine on renal excretory function during experimental sepsis in conscious rats
Authors: PALSSON J. , RICKSTEN S.‐E. , HOULTZ E. , LUNDIN S.
Published: January 2009

Background:Acute renal failure is a frequent complication in human sepsis. Various inotropic drugs are often used to improve central haemodynamics and renal function. The differential preservative role of the most commonly used inotropic drugs on renal function, in this condition, has previously not been extensively studied. The aim of this experimental animal study was therefore to compare the preserving effects of dopamine, dopexamine, dobutamine and saline on renal excretory function, after induction of sepsis in conscious rats.

Method:The effects of dopamine (DA) (2.5 μg · kg‐1· min‐1; n= 11), dopexamine (DX) (1 μg·kg‐1· min‐1; n=10), dobutamine (DB) (5 μg·kg‐1· min‐1; n=10) and saline (n=13) on the glom‐erular filtration rate (GFR), urine flow (UF), sodium excretion (SE) and fractional urinary excretion of sodium (FUENa) were studied and compared in conscious rats subjected to a 1‐h infusion of live E.colibacteria (109/h).

Results:In the saline‐treated control group, bacteria infusion decreased GFR, UF, SE and FUENaby 31%, 53%, 51% and 36% respectively, associated with a 16% decrease in mean arterial pressure (MAP), and a 10% increase in heart rate (HR). In the post‐E. colitreatment period, the fall in MAP was less pronounced with DX compared to both DB and control, while there was no difference between DX and DA. The increase in HR was most pronounced with DB. GFR decreased to a lesser extent with DX compared to DA, DB and control. UF and SE were better maintained with DX compared to DB and control, while there was no difference in FUENabetween the groups.

Conclusion:We conclude that dopexamine, to a greater extent than dopamine and dobutamine, improves renal excretory function in experimental septic shock.
Changes in pulmonary mechanics during laparoscopic gastroplasty in morbidly obese patients
Authors: DUMONT L. , MATTYS M. , MARDIROSOFF C. , VERVLOESEM N. , ALLÉ J. L. , MASSAUT J.
Published: January 2009

Background: Obesity is an important respiratory risk factor after abdominal surgery. Laparoscopic surgical techniques seem beneficial in obese patients in terms of respiratory morbidity, with a faster return to normal respiratory function. However, there is little information about intraoperative respiratory mechanics and about patient tolerance to abdominal insufflation in the morbidly obese.

Methods: We studied respiratory mechanics and arterial blood gases in 15 morbidly obese patients (mean BMI=45) undergoing laparoscopic gastroplasty under general anaesthesia and controlled ventilation. Respiratory mechanics were analysed using side‐stream spirometry.

Results:When compared to preinsufflation values, servocon‐trolled abdominal insufflation to 2.26 kPa caused a significant decrease in respiratory system compliance (31%), a significant increase in peak (17%) and plateau (32%) airway pressures at constant tidal volume with a significant hypercapnia but no change in arterial O2 saturation. Respiratory system compliance and pulmonary insufflation pressures returned to baseline values after abdominal deflation.

Conclusion: These alterations in pulmonary mechanics are less than those observed with comparable degrees of abdominal inflation in non‐obese patients, and were well tolerated. From the point of view of intraoperative respiratory mechanics, laparoscopic surgery is safe in morbidly obese patients.
Oral ketamine therapy in the treatment of postamputation stump pain
Authors: NIKOLAJSEN L. , HANSEN P. O. , JENSEN T. S.
Published: January 2009

Background: Hyperacti vity of N‐methy l‐D‐aspartate (NMD A) receptors may be one of the factors in the maintenance of post‐amputation stump pain.

Conclusion: NMDA receptor antagonists may have a potential in the treatment of neuropathic pain, including stump pain.
Severe complications associated with epidural and spinal anaesthesias in Finland 1987–1993 A study based on patient insurance claims
Authors: AROMAA U. , LAHDENSUU M. , COZANITIS D. A.
Published: January 2009

Background: The Patient Injury Act has been in effect in Finland since 1 May 1987. This legislation is a no‐fault compensation scheme and implies that if a patient during the course of medical treatment suffers any injury as a result of that treatment he or she may file a claim to the Patient Insurance Association (HA). From 1 May 1987to 31 December 1993, 23 500claims for compensation were made.

Methods:

All claims made to PIA involving spinal and epidural anaesthesias during the above period were collected and reviewed and a data base was prepared. The total number of anaesthetics given during this period was estimated by sending questionnaires to every hospitalin the country.

Results: Eighty‐six claims were associated with spinal and/or epidural anaesthesia. Respectively, the total the number of spinal and epidural anaesthesias administered was 550 000 and 170 000. There were 25 serious complications associated with spinal anaesthesia: cardiac arrests (2), paraplegia (5), permanent cauda equina syndrome (l), peroneal nerve paresis (6), neurological deficits (7), and bacterial infections (4). The 9 serious complications which were associated with epidural anaesthesia were: paraparesis (l), permanent cauda equina syndrome (I), peroneal nerve paresis (l), neurological deficit (I), bacterial infections (2), acute toxic reactions related to the anaesthetic solution (2), and overdose of epidural opioid (1).

Cxxonclusions:

According to this material the incidence of serious complications was 0.45:lO 000 following spinal and 0.52:lO 000 following epidural anaesthesia.
Preoperative infiltration of bupivacaine ‐ effects on pain relief and trauma response (cortisol and interleukin‐6)
Authors: ERIKSSON‐MJOBERG M. , KRISTIANSSON M. , CARLSTROM K. , EKLUND J. , GUSTAFSSON L. L. , ÖLUND A.
Published: January 2009

Hypothesis: Subcutaneous infiltration of bupivacaine before skin incision can reduce postoperative pain and modulate the stress response.

Methods: In a randomized study on pain relief after hysterectomy 29 patients were referred into one of three groups, receiving 30 ml of bupivacaine 0.25% with adrenaline, 30 ml of saline or no infiltration along the line of the proposed incision 10 min before start of surgery. A Visual Analogue Scale was used for repeated pain ratings. Postoperative pain relief was provided with patient‐controlled analgesia with intravenous morphine 0.04 mg/kg. Lockout time was 10 min. The immuno‐logical and endocrine stress response to trauma was reflected by blood interleukin‐6 (IL‐6) and cortisol concentrations measured during 72 h following skin incision.

Results: There were large individual variations in the accumulated postoperative consumption of morphine at 20 h after start of surgery. It was significantly reduced in patients receiving infiltration of bupivacaine. They used 39 mg (9–62) median (range) of intravenous morphine whereas the patients in the saline group used 65 mg (47–120) and patients in the control group used 54 mg (36–130) (P <0.05). Significant elevation of plasma IL‐6 and serum cortisol levels appeared in all groups with peak values at 3 h. There were no differences between the groups. There was a correlation between cortisol and IL‐6. Six of the 29 patients had a postoperative infection which was reflected in increased IL‐6 levels.

Conclusion: Preoperative subcutaneous infiltration of bupivacaine significantly reduced the postoperative consumption of intravenous morphine.
Antinociceptive effect of perioperative adenosine infusion in abdominal hysterectomy
Authors: SEGERDAHL M. , IRESTEDT L. , SOLLEVI A.
Published: January 2009

Background:Adenosine (ADO), and stable analogs thereof, have been shown to exert antinociceptive action in cutaneous and deep somatic pain under experimental and clinical conditions in animals and in humans. The aims of this randomized double‐blind placebo‐controlled study were to evaluate if a low dose of intravenous (i.v.) ADO could reduce the requirements of volatile anesthetic and postoperative opioid in connection to hysterectomy, where visceral nociception significantly contributes to pain.

Methods:

Forty‐three women, age 32–65 years, ASA I and 11, scheduled for abdominal hysterectomy, were assigned to receive an i.v. infusion of either adenosine, 80 μg. kg‐1min‐1, or placebo during surgery. Anesthesia was maintained with isoflurane (ISO)/N2O/ O2inhalation. Postoperatively, a reduced dose of 40 μg. kg‐1. min‐1was continued for 3 h.

Results:The end‐tidal (ET‐) IS0 was equal between groups before surgery. During surgery, the IS0 requirement was increased, compared to the preoperative level, in the placebo group, while the requirement declined in the ADO group. The overall IS0 requirement in the ADO group was reduced by 36% (P<0.002). The first 24 h postoperative opioid requirement, with equal resting pain in both groups, was 18% (P< 0.05)lower in the ADO group.

Conclusion:A low dose of perioperative adenosine infusion in abdominal hysterectomy reduces the requirements of volatile anesthetic and postoperative opioid analgesic.
Analysis of anaesthesia in patients suspected to be susceptible to malignant hyperthermia before diagnostic in vitro contracture test
Authors: BENDIXEN D. , SKOVGAARD L. T. , ØRDING H.
Published: January 2009

Background: It is well known that patients susceptible to malignant hyperthermia (MH) do not always develop clinical signs of MH at their first anaesthetic. Large material concerning this epidemiological problem do not exist. Therefore, we undertook the present investigation at the Danish Malignant Hyperthermia Register.

Methods: Retrospective analysis of anaesthetics given to 371 patients before in vitro contracture test (IVCT) for susceptibility to MH or before death of MH. Patients (or relatives in the case of a dead patient) gave information about previous anaesthetics and anaesthetic charts were collected and reviewed.

Results: Fifteen patients died of clinical MH, 112 patients survived an episode of suspected MH, and 244 patients were relatives of the above. Of the 127 patients with clinical signs of MH, 37% had received anaesthesia before, and trigger agents (potent inhalational agents and /or suxamethonium) were used in 98% of patients with no statistical difference between MH‐susceptible (MHS) and non‐susceptible (MHN) patients. Emergency anaesthesia was more frequent in patients with fulminant MH compared to those with abortive forms of MH (P< 0.01). Of the 244 relatives, 48% had received anaesthesia before MH was suspected in the family and trigger agents were used in 44% of the anaesthetics without statistical difference between MHS and MHN relatives. In 17 cases, trigger agents were used for anaesthesia after MH was suspected in the family, but before IVCT.

Conclusion: The clinical expressivity of the MHS phenotype was found to be 34%‐54%.
Can final EMG baseline be used as a reference to calculate neuromuscular recoverv?
Authors: MERETOJA O. A. , THEROUX M.
Published: January 2009

Background: Investigations recording recovery times of muscle relaxants have used initial or final baseline of a neuromuscular trace, or both, as a reference for data analysis. We evaluated the use of final baseline of EMG traces as a reliable reference to calculate recovery times.

Methods: We analyzed EMG traces from 82 children who had full spontaneous neuromuscular recovery following a single dose of mivacurium. Times from administration of mivacurium to 25, 50, 75, and 90% EMG recoveries were measured using both initial and final baselines as a reference. EMG traces with final baseline of 100±10% of the initial baseline were regarded as optimal. Recovery times from all other traces were compared to the times obtained from these optimal traces. Poor final baseline was defined as that of<80% of initial baseline. Inter‐group comparisons were made using Kruskal‐Wallis test followed by Mann‐Whitney U tests.

Results: EMG recovery times were similar for optimal traces whether the reference was the initial or the final baseline of the EMG trace. If the final baseline was used as the reference, then traces with poor final EMG baseline also showed similar neuromuscular recovery times. If the initial baseline was used as the reference for EMG traces with poor final baseline, then neuromuscular recovery times became 2655% longer (P<0.05).

Conclusions: We conclude that the final baseline of an EMG trace can be used as a reference for calculations of neuromuscular recovery times following a bolus injection of mivacurium.
Nitrous oxide has different effects on the EEG and somatosensory evoked potentials during isoflurane anaesthesia in patients
Authors: PORKKALA T. , JANIT V. , KAUKINEN S. , HAKKINEN V.
Published: January 2009

Background: Electroencephalogram (EEG) and somatosensory evoked potentials (SEPs) are altered by inhalation anaesthesia. Nitrous oxide is commonly used in combination with volatile anaesthetics. We have studied the effects of nitrous oxide on both EEG and SEPs simultaneously during isoflurane burst‐suppression anaesthesia.

Methods: Twelve ASA I‐II patients undergoing abdominal or orthopaedic surgery were anaesthetized with isoflurane by mask. After intubation and relaxation the isoflurane concentration was increased to a level at which an EEG burst‐suppression pattern occurred (mean isoflurane end‐tidal concentration 1.9 (SD 0.2) %. With a stable isoflurane concentration, the patients received isoflurane‐air‐oxygen and isoflurane‐nitrous oxide‐oxygen (FiO2 0.4) in a randomized cross‐over manner. EEG and SEPs were simultaneously recorded before, and after wash‐out or wash‐in periods for nitrous oxide. The proportion of EEG suppressions as well as SEP amplitudes for cortical N20 were calculated.

Results: The proportion of EEG suppressions decreased from 53.5% to 34% (P< 0.05) when air was replaced by nitrous oxide. At the same time, the cortical N20 amplitude was reduced by 69% (P < 0.01).

Conclusion: The results suggest that during isoflurane anaesthesia, nitrous oxide has a different effect on EEG and cortical SEP at the same time. The effects of nitrous oxide may be mediated by cortical and subcortical generators.
The haemodynamic effects of rocuronium and vecuronium are different under balanced anaesthesia
Authors: STEVENS J. B. , HECKER R. B. , TALBOT J. C. , WALKER S. C.
Published: January 2009

Background: Rocuronium has been reported to have minimal haemodynamic effects. However, this conclusion has been drawn primarily from investigations conducted under narcotic‐based anaesthesia. This study was designed to evaluate the cardiovascular effects of rocuronium under isoflurane/N20/fentanyl anaesthesia and to compare rocuronium's haemodynamic effects to those of vecuronium and pancuronium.

Methods: Anaesthesia was induced with fentanyl 2 μg/kg, thiopentone 4 mg/kg, and suxamethonium 0.5 mg/kg in 75 ASA I or II patients. After tracheal intubation, anaesthesia was maintained with isoflurane 0.5% and N20 50% in oxygen. Five min after intubation (baseline), patients randomly received either vecuronium 100 μg/kg, rocuronium 600 μg/kg, rocuronium 900 μg/kg, rocuronium 1200 μg/kg, or pancuronium 140 μg/kg. One min after administration of muscle relaxant, mean arterial pressure (MAP) and heart rate (HR) were recorded and were subsequently measured at 1‐min intervals for the next 4 min.

Results: HR decreased significantly (P<0.05) at all times compared to baseline in patients receiving vecuronium. HR significantly (P < 0.05) increased in those receiving rocuronium 1200 μg/kg or pancuronium. Patients who received vecuronium had a sigruficant (P< 0.05) decrease in MAP at all times compared to baseline. Comparing results between groups, patients who received rocuronium or pancuronium had significantly (P < 0.05) higher MAP compared to those administered vecuronium.

Conclusion: The haemodynamic effects of rocuronium and vecuronium are different under balanced anaesthesia. Rocuronium may attenuate the fall in MAP that often occurs under balanced anaesthesia without surgical stimulation.
Tramadol in the treatment of postanesthetic shivering
Authors: WITTE J. DE , DELOOF T. , VEYLDER J. DE , HOUSMANS P. R.
Published: January 2009

Background: As an inhibitor of the reuptake of serotonin and norepinephrine in the spinal cord, the mechanism of action of tramadol resembles that of nefopam, which has been used in the treatment of postanesthetic shivering.

Methods: In a randomized, placebo‐controlled, double‐blind study, we assessed the effects of tramadol (0.5 mgskg‐1, 1 mg kg‐1 and 2 mg kg‐1 i.v.) or normal saline on shivering after a standardized general anesthesia in 40 adult patients, ASA physical status I or II (group l), and in 64 adult patients regardless of the foregoing general anesthesia and ASA physical status (group 2).

Results: Tramadol l mg. kg‐1 or more abolished shivering completely 5 min after treatment in all patients of groups 1 and 2. In group 1, the three dosages of tramadol were not statistically different in lowering the severity and prevalence of postanes thetic shivering. Tramadol 0.5 mg kg‐1 was significantly slower than tramadol l or 2 mg. kg‐1 in tempering the severity as well as lowering the prevalence of postanesthetic shivering in group 2.

Conclusion: Tramadol's distinct features in the treatment of shivering reside in its high safety profile and weak sedative properties, particularly in patients with poor cardiorespiratory reserve, in outpatients and on recurrence of shivering.
Magnesium ‐ a profibrillatory or antifibrillatory drug depending on plasma concentration, heart rate and myocardial perfusion
Authors: AUPET J. F. , FREYSZ M. , FAUCON G. , LOUFOUA‐MOUNDANGA J. , COQUELIN H. , TIMOM Q.
Published: January 2009

Background: The opinions on the efficacy of magnesium as an antiarrhythmic drug vary considerably. The action of magnesium on vulnerability to fibrillation was therefore investigated in anaesthetized, open‐chest pigs under different conditions as regards plasma concentration, heart rate and myocardial perfusion.

Methods: Vulnerability to fibrillation was assessed by electrical fibrillation threshold (EFT), measured with 100‐ms duration diastolic impulses. These stimuli were delivered to the heart normally perfused, at a usual (90 and 120 beats/min) or accelerated (180 beats/min) rate. Vulnerability to fibrillation was also assessed at the high rate (180 beats/min) in the heart made isch‐aemic by complete occlusion of the left anterior descending coronary artery near its origin. EFT was then measured at the end of occlusion periods which were of increasing duration (30, 60, 90, 120 s). Monophasic action potential (MAP) duration, intraventricular conduction time, left ventricular dP/dt max (LVdP/dt max) and mean blood pressure were concurrently measured.

Results: In the absence of ischaemia, 5 μmol kg‐1. min‐1 magnesium i.v. infusion, which raised plasma concentration to 1.78±0.14 mmol/L, lowered EFT, measured at the rate of 116 beats/min, from 14.0±1.1 to 6.8±1.0 mA (P<0.001), without significant variation of the other parameters. Administered as previously or in a markedly higher dose (400 μmol kg‐1 loading dose and 10 pmol kg‐1 min‐1 infusion) which raised plasma concentration up to 4.84±0.52 mmol/L, magnesium significantly influenced neither EFT nor MAP duration, reduced by the high rate (180 beats/min) to 6.2–6.7 mA and 212–220 ms respectively. Under the same conditions, at the same 180 beats/min rate, ischaemia brings about a fall of EFT, from 6.9 down to nearly 0 mA, with occurrence of fibrillation, in approximately 120 s. Magnesium failed to slow this fall and to delay the onset of fibrillation. In contrast, within the minutes following the end of occlusion, magnesium increased EFT to a great extent (from 7.1 ± 20.4 to 13.5±0.7 mA, P <0.001), with a significant prolongation of MAP duration (212±6 to 234±8 ms, P < 0.01).

Conclusion: Magnesium may develop profibrillatory or antifibrillatory effects depending on plasma concentration, heart rate and myocardial perfusion.
A tube in the pharynx for emergency ventilation
Authors: BUND M. , WALZ R. , LOBBES W. , SEITZ W.
Published: January 2009

Background:

If the endotracheal placement of a nasal advanced tube fails, ventilation via this tube could bridge the time until a fibreoptic bronchoscope is available. This study investigates the efficiency of ventilation via a tube resting with its tip in the pharynx near the glottis.

Methods: In 20 patients respiratory data during ventilation via a pharyngeally placed tube were recorded by means of pulse oximetry, capnometry and side‐stream spirometry. Results were compared with those measured previously in the same patients during conventional facemask ventilation.

Results: Oxygen saturation and end‐tidal carbon dioxide concentration remained unchanged using ventilation via facemask (SO2 98.5±0.9%, FECO2 4.5±0.7 vol%) or pharyngeal tube (SO2 98.6±0.7%, FECO2 4.8±0.4 vol%). No significant differences were found between the two groups with regard to peak airway pressure, tidal volume leakage, compliance and resistance of the respiratory system.

Conclusions: Our results suggest an effective ventilation and oxygenation via a tube placed with its tip in the pharynx. This technique may be helpful during difficult and prolonged nasal intubation.
Blockade of ATP‐sensitive K+ channel abolishes the anti‐ischemic effects of isoflurane in dog hearts
Authors: NAKAYAMA M. , FUJITA S. , KANAYA N. , TSUCHIDA H. , NAMIKI A.
Published: January 2009

Background:Although isoflurane is reported to have a protective effect against ischemic damage on the myocardium, the mechanisms of this effect are not clear. Activation of adenosine triphosphate sensitive potassium (KATP) channels is indicated to protect myocardium during ischemia. Thus, it was hypothesized that if isoflurane could activate KATP channels, blockade of KATP channels would decrease its cardioprotective effect.

Methods:Mongrel dogs, anesthetized with morphine, urethane, and chloralose, were subjected to 15 min of left anterior descending coronary artery occlusion followed by 60 min reperfusion. The dogs were divided into three groups: the control group (n=8), IS0 group (n=8) and ISOGC group (n=8). In the IS0 and ISOGC groups, 1 MAC of isoflurane was administrated during ischemia and reperfusion. In the ISOGC group, 0.3 mg/ kg of glibenclamide, the KATP channel blocker, was given 45 min before ischemia. Full‐thickness samples of myocardium were obtained and the concentrations of adenosine monophosphate, adenosine diphosphate, adenosine triphosphate (ATP), creatine phosphate and lactate in the endocardial portion of the myocardium were measured.

Results:The ischemia‐reperfusion caused a 25.4% and 27.6% reduction of myocardial ATP in the control and ISOGC groups, respectively. In contrast, the IS0 group showed only 11.0% reduction of AT, which was significantly lower compared to the other groups (P< 0.01).

Conclusions:Our results shows that blockade of the KATP channel abolishes cardioprotective effects of isoflurane in myocardial ischemia‐reperfusion. The KATP channel may play a role in the ATP‐sparing effect of isoflurane.
Long QT interval syndrome with increased QT dispersion
Authors: MICHALOUDIS D. , BISHINIOTIS TH.
Published: January 2009

This case report describes the anaesthetic management of a patient with sporadic‐type long QT interval syndrome (LQTS), and increased QT dispersion, who presented for removal of an ovarian cyst. Beta adrenergic blockade and adequate depth of anaesthesia for successful management is emphasized. The Successful use of epidural administration of lignocaine and opioids in addition to general anaesthesia is described.
Intrathecal morphine for post‐stemotomy pain in patients with myasthenia gravis: effects on respiratory function
Authors: NILSSON E. , PERTTUNEN K. , KALSO E.
Published: January 2009

Background: Thymectomy can induce a remission or at least an improvement in myasthenia gravis (MG) patients. After sternotomy MG patients with compromised muscle strength need an excellent postoperative pain relief. This study was designed to evaluate the efficacy of intrathecal morphine (ITM) on ventilatory function among MG patients undergoing trans‐sternal thymectomy, when intravenous morphine served as control.

Methods: Twenty consecutive MG patients were randomised to receive either morphine (10 μg/kg) intrathecally at induction or intravenous morphine (30 μg/kg) with a patient‐controlled analgesia (PCA) device. Anaesthesia was standardised. Forced vital capacity (FVC), forced expiratory volume in 1 s (FEVl), respiratory rate, oxygen saturation, arterial blood gases, pain intensity and morphine consumption were assessed during 48 hours.

Results: The mean age of the patients was 35±3.4 years and the mean duration of the disease 1.9±0.5 years. According to Osserman's classification 70% of the patients belonged to Class IIA and 30% to Class IIB. ITM restored ventilatory function significantly better than iv PCA morphine. FVC recovered to 60% and FEV1 to 57% of the baseline values in the ITM group compared with 32% (P < 0.05) and 37% in the PCA morphine group, respectively. Postpuncture headache occurred in 4/10 patients.

Conclusion: Intrathecal morphine provided effective postoperative analgesia and significantly improved ventilatory function when compared with intravenous morphine.
Motor power pharmacodynamics of subarachnoid hyperbaric 5% lidocaine in the sitting position
Authors: RUSHMER J. , MILES W. , JONES R. D. M. , HO J. Y. W. , CHEUNG C. K. W. , CHAN S. S. C.
Published: January 2009

Background:Repetitive dynamometric measurement using a plantar flexion power device (PFPD) provides detailed data describing the onset and offset of motor block following spinal administration of lidocaine. The aim of this study was to evaluate administration of two doses of spinal lidocaine in the sitting position to determine whether our dynamometric model produces data consistent with our current understanding of the pharmacokinetics of subarachnoid, hyperbaric, 5% lidocaine.

Methods:Twenty male patients (54 to 80 yr) undergoing cystos‐copy received spinal anaesthesia with either 75 mg (n=10) or 100 mg of hyperbaric lidocaine 5%, in the sitting position, under standardised conditions. Plantar flexion muscle power was recorded during onset and offset of anaesthesia using a load cell interfaced with a computer (PFPD).

Result:Onset of paralysis following spinal block in the sitting position was rapid and complete with motor power declining exponentially to 5% of preoperative values by 8.5 min in all patients. There was no difference in decay or recovery of plantar flexion motor power data between dosage groups in the sitting position. Measurement using the PFPD shows that onset of motor paralysis is described by an exponential decay and that motor recovery occurs at a fixed rate. Extent of block to cold and pinprick was similar in both dosage groups in the sitting position (median T4).

Conclusion:This study shows that in the sitting position, doses less than 75 mg of 5% hyperbaric lidocaine are required to significantly improve ambulatory times.