bluuebunny/crossref_metadata_2025 huggingface dataset:
A risk score to predict the probability of postoperative vomiting in adults
Authors: Apfel C. C. , Greim C. A. , Haubitz I. , Goepfert C. , Usadel J. , Sefrin P. , Roewer N.
Published: January 2009

Background: The aim of this study was to identify factors most relevant for postoperative vomiting (PV) and to develop a risk score to predict the probability of PV.

Methods: Adult inpatients scheduled for elective ear, nose and throat (ENT) surgery under general anaesthesia were offered to participate in a prospective study for PV over 24 h. No prophylactic antiemetics were used. The data of 1137 patients were randomized and split into an evaluation set (n=553) and a validation set (n=584). The evaluation set was subjected to logistic regression analysis to quantify the relative impact of anaesthetic, surgical and individual factors and to develop a risk score. The score was then tested by applying it to the validation set. The area under a receiver operation characteristic (ROC) curve was calculated and the predicted and actual incidences of patients were correlated.

Results: In the evaluation set, patient‐related factors (female gender, young age, non‐smoking, history of PV or motion sickness) and a high duration of anaesthesia were independent risk factors for PV. The probability of PV could be estimated from the equation: PV = 1/(1 + exp(‐z)) where z=1.28 · (gender)‐0.029· (age)‐0.74·(smoking)+0.63·(history of PV or motion sickness)+0.26 · (duration)‐0.92. In the validation set this score achieved an area under the ROC‐curve of 0.78 and the actual incidence correlated strongly with the predicted risks (R2=0.93, P<0.001).

Conclusion: The data suggest that the probability of PV following ENT surgery under inhalational anaesthesia with low‐dose opioids can be predicted by a score mainly based upon patient‐related risk factors.
Effects of intravenous anesthetics on bacterial elimination in human blood in vitro
Authors: Heller A. , Heller S. , Blecken S. , Urbaschek R. , Koch T.
Published: January 2009

Backround: Since anesthetics are widely used in critically ill patients, this study investigates anesthetic effects on neutrophil and monocyte function concerning bacterial elimination in human whole blood.

Methods: The effects of thiopental (20 and 200 μg/ml), propofol (5 and 50 μg/ml), midazolam (0.15 and 1.5 μg/ml) and ketamine (3 and 30 μg/ml) on elimination of Escherichia (E.) coli from whole blood were investigated in vitro after incubation for 1 h in both clinical (1) (n=10) and 10‐fold higher (h) (n=11) concentrations. These data were compared to neutrophil and monocyte phagocytosis (1; n=6) and burst activity (1; n=10, h; n=11), measured by flow cytometry. To enable quantification of the clearance process, a defined number of 105 colony forming units of E. coli were added to the blood assays and bacterial growth was determined.

Results: All anesthetics delayed bacterial clearance from the blood in the 10‐fold concentration (P<0.05). Thiopental (1+h) and propofol (h) suppressed neutrophil (59±3% and 38±6%) and monocytic (45±6% and 30±11%) oxidative burst (P<0.01). Phagocytosis was reduced even after propofol (1) in polymorphonuclear leukocytes (PMN) (34±9%; P<0.05) and monocytes (35±11%). Ketamine (h) prolonged bacterial elimination (P<0.01), which did correlate with inhibition of monocytic phagocytosis, by 26±14%. Midazolam application (h) resulted in an inhibition of PMN‐respiratory burst by 19±6% (P<0.05) and impaired bacterial clearance (P<0.05).

Conclusion: Thiopental, propofol, midazolam and ketamine affect E. coli clearance and neutrophil and monocyte oxidative burst and phagocytosis in vitro only in high concentrations, while thiopental inhibited monocytic burst and propofol impaired PMN phagocytosis even in clinically used concentrations. These data suggest that i.v. anesthetics in concentrations recommended for general anesthesia seem to have minor influence on the investigated host defense mechanisms.
Prognostic importance of automated ST‐segment monitoring after coronary artery bypass graft surgery
Authors: Yazigi A. , Richa F. , Gebara S. , Haddad F. , Hayek G. , Antakly M.‐C.
Published: January 2009

Background: Automated ST‐segment monitors are widely used in cardiac surgery units. The purpose of this study was to determine if cardiac morbidity and mortality, after CABG surgery, are predicted by ECG ST‐segment changes on automated monitors.

Method: One hundred patients, who underwent CABG, were included in this prospective study. ST‐segment deviations were recorded by an automated ST monitor, in the ICU, for 24 h after surgery. A reversible ST depression of more than 0.1 mV or a ST elevation of more than 0.2 mV and for at least 1 min were considered as significant episodes. Adverse cardiac outcomes were defined as: myocardial infarction (MI), severe left ventricular failure, ventricular fibrillation (VF) and cardiac‐related death.

Results: Sixty patients (group 1) presented significant episodes of ST deviation (6δ5 episodes per patient). Forty patients (group 2) were free from ST changes. Eight patients from group 1 had postoperative adverse cardiac outcomes: 5 MI, 2 VF and 1 cardiac‐related death. Patients from group 2 were all free from adverse cardiac outcomes. Automated ST‐segment analysis during the first 24 h had a positive predictive value of 13% and a negative predictive value of 100%.

Conclusion: Automated ST analysis is a non‐invasive, sensitive and very easy‐to‐use monitoring system to screen patients who may develop myocardial ischemia and cardiac complications after CABG surgery.
The effects of nitric oxide inhalation on respiratory mechanics and gas exchange during endotoxaemia in the pig
Authors: Dahm P. L. , Jonson B. , De Robertis E. , Myhre E. , Svantesson C. , Thörne J. , Blomquist S.
Published: January 2009

Background: In the adult respiratory distress syndrome, nitric oxide (NO) inhalation improves oxygenation through reducing ventilation‐perfusion mismatching, but detailed information on the pulmonary effects of NO inhalation in septic shock is scarce. The present study investigated the effects of inhaled NO on alveolar dead space (Vdalv) and venous admixture as well as on respiratory system compliance (Crs) and respiratory system resistance (Rrs) in a porcine model of septic shock. Protective effects of NO are discussed.

Methods: Thirteen anaesthetised and ventilated pigs were given an infusion of endotoxin for an observation time of 220 min to induce acute lung injury (ALI). In the NO‐early group (n=6), an inhalation of 60 ppm NO was started simultaneously with the endotoxin infusion and continued for 190 min. In 7 control/NO‐late animals, 60 ppm NO was administered for 30 min following 190 min of endotoxin infusion. Haemodynamics, single‐breath CO2‐, pressure‐, and flow signals were recorded.

Results: Endotoxin induced haemoconcentration, pulmonary vasoconstriction, and a decrease in Crs, while venous admixture, Vdalv, and Rrs increased. In the NO‐early group, the pulmonary vasoconstriction was attenuated, no increase in pulmonary venous admixture or in Vdalv was seen before cessation of NO, and the improvements in oxygenation outlasted the NO inhalation. In the control/NO‐late group, the NO inhalation reversed the changes in dead space and venous admixture. NO had no effect on the changes in respiratory mechanics.

Conclusion: In porcine ALI, 60 ppm NO diminishes pulmonary vasoconstriction and improves gas exchange by reducing pulmonary venous admixture and alveolar dead space, but does not prevent a fall in Crs. NO inhalation may help prevent longlasting pulmonary failure.
Percutaneous dilatational tracheostomy versus conventional surgical tracheostomy
Authors: Holdgaard H. O. , Pedersen J. , Jensen R. H. , Outzen K. E. , Midtgaard T. , Johansen L. V. , Møller J. , Paaske P. B.
Published: January 2009

Background: As no clinical randomised studies have previously been performed comparing complications with the Ciaglia Percutaneous Dilatational Tracheostomy Introducer Set (PDT) and conventional surgical tracheostomy (TR), we designed a study with the aim of comparing the efficacy and safety of the two techniques.

Methods: Sixty patients selected for elective tracheostomy were randomised for either PDT (30 patients) or TR (30 patients). All patients had general anaesthesia and were ventilated with 100% oxygen. Furthermore, lidocaine with epinephrine 1% (3–5 ml) was used for local analgesia and to minimise bleeding during the procedure.

Results: The median time for insertion of the tracheostomy tube was 11.5 min (range 7–24 min) in the PDT group and 15 min (range 5–47 min) in the TR group (P<0.01). Complications during the procedure were cuff puncture of the endotracheal tube in 5 cases in the PDT group. Minor bleeding was encountered in 6 cases in the PDT group as opposed to 24 cases in the TR group (P<0.01), major bleeding in none versus 2 cases, respectively. In 8 cases in the PDT group, increased resistance to insertion of the tracheostomy tube was met by further dilatation. During the post‐tracheostomy period, complications occurred with minor bleeding in 2 cases in the PDT group as opposed to 9 cases in the TR group (P<0.05), and major bleeding was encountered in 1 case in each group. Minor infections were encountered in 3 cases in the PDT group as opposed to 11 cases in the TR group (P<0.01). Major infection was encountered in none versus 8 cases, respectively (P<0.01).

Conclusion: Our results indicate that the percutaneous dilatational tracheostomy technique performed with the Ciaglia Introducer Set is effective, safe and superior to conventional surgical tracheostomy as immediate complications as well as complications with the tracheostomy tube in situ are fewer and of less severity.
Increased platelet microvesicle formation is associated with mortality in a porcine model of endotoxemia
Authors: Eriksson M. , Nelson D. , Nordgren A. , Larsson A.
Published: January 2009

Background: Gram‐negative sepsis in humans and endotoxemia in pigs induce the formation of platelet microvesicles. These microvesicles are active in homeostasis and may thus contribute to the outcome in patients with activated coagulation and fibrinolysis. We decided to prospectively evaluate the effects of endotoxemia on microvesicle formation and some common physiologic variables against survival in a porcine model.

Methods: Nineteen included pigs were anesthetized, monitored and subjected to an infusion of E. coli endotoxin. Microvesicle formation was determined by flow cytometry.

Results: The formation of microvesicles was significantly increased in the 6 pigs that died during endotoxin exposure. This increased formation became significant from the 3rd hour of endotoxemia. Microvesicle formation did not increase in surviving endotoxemic pigs. Cardiac index, mean arterial blood pressure, base excess and systemic vascular resistance index were distinctly reduced in the animals that died as compared to those surviving the endotoxemic period.

Conclusion: The increased formation of platelet microvesicles seems to be associated with poor prognosis in porcine endotoxemia. Since microvesicles are active in coagulation, they may contribute to the derangement of the coagulation system caused by endotoxemia. Different degrees of microvesicle formation may reflect inter‐individual responses to a given challenge.
Comparison of analgesic efficacy of oxycodone and morphine in postoperative intravenous patient‐controlled analgesia
Authors: Silvasti M. , Rosenberg P. , Seppälä T. , Svartling N. , Pitkänen M.
Published: January 2009

Background: Morphine has been the standard opioid in patient‐controlled analgesia (PCA). Oxycodone, the analgesic potency of which in i.v. administration has been suggested to be slightly greater than that of morphine, has not yet been studied for its efficacy in PCA.

Methods: Fifty patients, undergoing a plastic reconstruction of the breast or a major operation of the vertebrae, such as lumbar spinal fusion, used PCA for postoperative pain. Patients were randomized to receive either morphine 45 μg/kg or oxycodone 30 μg/kg as i.v. bolus doses. Patients were assessed for pain with a visual analogue scale (VAS) and side effects at 3, 9 and 24 h. Venous blood samples for the measurement of plasma concentration of oxycodone and that of morphine and its metabolites were taken.

Results: In this study patients needed, on average, the same amount of oxycodone and morphine in the recovery room and on the ward. There was no difference in the quality of analgesia (VAS) or incidence of side effects, such as nausea, vomiting, pruritus and urinary retention. The plasma concentrations of morphine‐6‐glucuronide showed that this metabolite might contribute to the analgesia resulting from morphine administration.

Conclusions: The same dose of intravenous oxycodone and morphine administered by PCA pump was needed for immediate postoperative analgesia. The two drugs appear to be equipotent.
Postoperative nausea and vomiting with special reference to risk factors and prevention in laparoscopic surgery
Authors: Koivuranta M.
Published: January 2009

The current incidence, risk factors and prevention of postoperative nausea and vomiting (PONV) were prospectively evaluated in 1703 inpatients. The objectives of the study were: 1) to create a predictive model based on patient characteristics in order to enable the estimation of the risk for PONV, 2) to ascertain the antiemetic efficacy of prophylactic intravenous ondansetron in comparison with droperidol and placebo against PONV following laparoscopic surgery, and 3) to evaluate the antiemetic effectiveness of combining ondansetron with a low dose of droperidol in high‐risk inpatients.

The incidence of nausea and vomiting after common surgical procedures was high. In the recovery room, the overall incidence of nausea and vomiting was 18% and 5%, respectively, and over the whole 24‐h observation period the respective figures were 52% and 25%. The most significant predictive factors associated with an increased risk for the symptoms were female sex, a previous history of postoperative nausea and vomiting, a history of motion sickness, a longer duration of surgery and non‐smoking. Based on these five items, a risk score predicting nausea and vomiting was constructed with a moderately good discriminating power, as judged from the area under the receiver operating characteristic curve.

Intravenous ondansetron 4 mg was ineffective in the prevention of postoperative nausea and vomiting after laparoscopic cholecystectomy. A higher dose of prophylactic ondansetron 8 mg effectively reduced the incidence and alleviated the intensity of PONV in women scheduled to have laparoscopy for gynaecological and general surgical procedures, as compared with placebo. The antiemetic efficacy of prophylactic ondansetron 8 mg and droperidol 1.25 mg was similar as for overall nausea during the 24‐h observation period, but ondansetron seemed to be slightly more efficacious in preventing vomiting. Both ondansetron and droperidol were well‐tolerated with only minor side‐effects.

In a high‐risk, female, inpatient laparoscopic population, with a mean estimated risk of 65% for PONV, prophylactically administered ondansetron 8 mg in combination with either a 0.75 mg or 1.25 mg dose of droperidol reduced the incidence of post‐operative nausea to 35% and that of vomiting to 15% during the first 24 h after surgery. Of these drug combinations, the smaller dose of droperidol resulted in less postoperative sedation than the higher dose; both combinations being otherwise equally well‐tolerated without serious adverse events.

These results indicate that postoperative nausea and vomiting can, to some extent, be predicted by a few patient characteristics, and in laparoscopic surgery ‐ which is associated with an increased risk for PONV ‐ the incidence can be reduced with either a single dose of ondansetron or droperidol or a combination of these drugs.
Epidural abscess complicating epidural anesthesia and analgesia: An analysis of the literature
Authors: Kindler C. H. , Seeberger M. D. , Staender S. E.
Published: January 2009

Background: Epidural abscess is a serious complication of epidural block. Because of its low incidence, the risk factors and the symptoms and cause of epidural abscess related to epidural anesthesia and analgesia are not well known by anesthesiologists.

Methods: A computer‐assisted search of the literature on epidural catheter‐related abscess was performed to describe the clinical course and bacteriology of this complication, to determine possible risk factors, and to assess the index of suspicion among physicians.

Results: Forty‐two patients with a catheter‐related epidural abscess were identified. Only in 15 patients was the correct diagnosis considered initially. The time from insertion of the epidural catheter to symptoms varied between 1 and 60 d. Initial symptoms included back pain, fever, and leukocytosis. The time from symptoms to treatment was a few hours to 108 d. Interval from first symptoms to treatment was significantly longer in patients with persistent neurologic deficits compared with patients who completely recovered. Staphylococcus aureus was the most common etiologic agent. Outcome was reported in 39 patients, but only 19 made a full recovery.

Conclusion: The index of suspicion among anesthesiologists, other physicians and nurses taking care of patients with epidural catheters must be increased for this complication; this should shorten the interval from symptoms to treatment and lower the incidence of neurological sequelae.
Vomiting, retching, headache and restlessness after halothane‐, isoflurane‐ and enflurane‐based anaesthesia: An analysis of pooled data following ear, nose, throat and eye surgery
Authors: VAN DEN Berg A. A. , Honjol N. M. , Mphanza T. , Rozario C. J. , Joseph D.
Published: January 2009

Background: Isoflurane has exceeded halothane and enflurane in usage. A literature search, however, revealed no data comparing the effects on emesis, headache and restlessness of these three agents.

Methods: With hospital ethics committee approval and patient consent, a prospective, randomised, double‐blind study of 556 patients undergoing ENT and eye surgery was undertaken to evaluate the effects of halothane, isoflurane and enflurane on vomiting, retching, headache and restlessness until 24 h after anaesthesia. Balanced general anaesthesia was administered comprising benzodiazepine premedication, induction with thiopentone‐atracurium‐morphine (ENT patients) or fentanyl (eye patients), controlled ventilation and maintenance with either halothane 0.4–0.6 vol% (n = 186), isoflurane 0.6–0.8 vol% (n = 184) or enflurane 0.8–1 vol% (n=186) in nitrous oxide 67% and oxygen.

Results: The three study groups were comparable, and comprised comparable subgroups having ear, nose, throat, intraocular and non‐intraocular surgery. During early recovery from anaesthesia, the respective requirements for halothane, isoflurane and enflurane for analgesia (7%, 9% and 10%), frequency of emesis (6%, 8% and 8%), antiemetic requirements (1%, 1% and 2%), restlessness‐pain scores and time spent in the recovery ward (27 SD 10, 31 SD 12 and 26 SD 9 min) were similar. During the ensuing 24‐h postoperative period, patients who had isoflurane experienced emesis less often than those who had halothane (36% vs 46%, P<0.025) but did so with similar frequency to those who had enflurane (46% vs 41%). Antiemetic requirements were least in those given isoflurane (isoflurane 12%, halothane and enflurane 23% each, P<0.005), but headache and analgesic requirements were similar.

Conclusion: Isoflurane induces less postoperative emesis than halothane, but headache is similarly frequent after anaesthesia with any of these agents.
Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits
Authors: Ma D. , Sapsed‐Byrne S. M. , Chakrabarti M. K. , Whitwam J. G.
Published: January 2009

Background:It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic.

Methods:PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose‐response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg−1i. v. or midazolam 0.05 mg · kg−1i. v. on the effects of propofol and fentanyl respectively on PNA were studied.

Results:Propofol and fentanyl caused a dose‐dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg−1i. v. and 32 μg · kg−1i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg−1reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg−1. The mean ED50s, calculated from dose‐response curves, were 5.4 mg · kg−1, 3.9 μg · kg−1and 0.4 mg · kg−1for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg−1i. v. or midazolam 0.05 mg · kg−1i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg−1and 8 μg · kg−1, respectively.

Conclusion:Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.
Spinal cord blood flow after intrathecal injection of ropivacaine and bupivacaine with or without epinephrine in rats
Authors: Kristensen J. D. , Karlsten R. , Gordh T.
Published: January 2009

Background: Ropivacaine is a new local anaesthetic available for spinal and epidural anaesthesia. When new drugs are being introduced for spinal application, their effect on spinal cord blood flow (SCBF) should be studied for safety and toxicological aspects. In the present study, SCBF was studied after intrathecal (i. t.) application of ropivacaine and bupivacaine with and without epinephrine.

Method: SCBF was measured continuously in spontaneously breathing, enflurane/N2O anaesthetized rats, using laser‐Doppler flowmetry technique. The spinal cord was exposed by laminectomy at the L1‐L2 level, and a laser‐Doppler probe was placed over the dorsal horn, allowing on‐line registration of SCBF in a tissue hemisphere of 1–2 mm. Relative changes in SCBF were then measured on‐line after i. t. administration of increasing doses of ropivacaine, bupivacaine or bupivacaine with epinephrine.

Results: Ropivacaine and bupivacaine decreased SCBF in a dose‐dependent manner. In contrast, the reduction in SCBF produced by bupivacaine + epinephrine (Bupi+Epi) was equal for all doses of bupivacaine. The order of magnitude of SCBF decreases was Bupi + Epi >ropivacaine>bupivacaine. The maximal decrease in SCBF at the highest concentration given (10 mg/ml) was 37±6% for ropivacaine, 27±7% for bupivacaine and 40 ±6% for bupivacaine + epinephrine.

Conclusion: Ropivacaine and bupivacaine produce a dose‐related, transient decrease in SCBF following i. t. administration in anaesthetized rats. However, the decrease in SCBF produced by both ropivacaine and bupivacaine was less than that produced by bupivacaine, when epinephrine was added in a concentration of 5 μg/ml. These results suggest that ropivacaine, like bupivacaine, may be used for spinal anaesthesia without important effects on SCBF.
Convulsions, ataxia and hallucinations following propofol
Authors: Bendiksen A. , Larsen L. M.
Published: January 2009

A 6‐year‐old fit girl experienced convulsions 44 h after an otherwise uneventful anaesthesia with propofol, alfentanil and nitrous oxide. As an underlying pathology was suspected, the child was kept sedated for 6.5 h for further investigations. During this period she received a continous infusion of propofol amounting in total to 1600 mg. After having regained consciousness, she was strikingly ataxic and remained so for 5 days. During this period she also experienced two episodes of hallucinations lasting about 2 h. Investigations including lumbar puncture, EEG, cerebral CT and MR scan could not explain the neurological symptoms. She recovered without long‐term sequelae.
Systemic air embolism as a possible cause of cardiac arrest during endoscopic treatment of pulmonary haemangioma using a diode laser
Authors: Jacobsen F. , Gullaksen K. , Johansen L. Vendelbo
Published: January 2009

Air embolism is a known but rare complication to endoscopic laser surgery. A case of nearly lethal air emboli as a complication to endoscopic laser surgery using a diode laser in the lungs is described. The case illustrates that even after prolonged resuscitation a successful outcome can be obtained.
Analgesic efficacy and safety of preoperative versus postoperative ketorolac in paediatric tonsillectomy
Authors: Rømsing J. , ØStergaard D. , Walther‐Larsen S. , Valentin N.
Published: January 2009

Background: Tonsillectomy is a common procedure in childhood resulting in significant morbidity due to pain. The aim of this study was to evaluate the analgesic efficacy and safety of a single dose of ketorolac i.v. given before or after tonsillectomy, compared to placebo.

Methods: A randomized, double‐blind, placebo‐controlled study was performed in 60 children, 5 to 15 years of age, admitted for tonsillectomy Patients were allocated to receive ketorolac 1 mg . kg‐1 i.v. or placebo. Postoperative pain was assessed by self‐report 1.5, 3, 5, and 24 h after surgery.

Results: Pain scores were significantly lower for both ketorolac groups compared to the placebo group 1.5, 3, and 5 h after surgery (P<0.05). Pain scores were lowest in the preoperative ketorolac group 1.5 to 5 h after surgery, and significantly fewer children in this group had fentanyl 0 to 1.5 h after surgery. But no significant differences were found between pain scores of the preoperative and postoperative ketorolac groups in the first 24 h after surgery. Acetaminophen consumption during the first 5 h after surgery was significantly less in patients receiving ketorolac (P<0.05). Patients in the preoperative ketorolac group had a significantly lower incidence of postoperative vomiting (P<0.05). There were no significant differences in the incidence of postoperative bleeding between groups. Three children in the preoperative, 5 children in the postoperative ketorolac group, and 5 children in the placebo group experienced postoperative haemorrhage.

Conclusion: This study indicates that a single dose of ketorolac 1 mg . kg‐1 i.v. administered either before or immediately after surgery improves postoperative analgesia in children after tonsillectomy without evidence of increased incidence of bleeding.
Stability of local anesthetics in heparinized blood, plasma and sulfuric acid
Authors: Adams H. A. , Pawlik D. , Bauer H. , Mautgreve W.
Published: January 2009

Background: This study was undertaken to investigate the stability of local anesthetics in different media.

Methods: 60 patients with axillary plexus block, using prilocaine, mepivacaine or lidocaine 1%, or with lumbar epidural catheter‐anesthesia, using bupivacaine 0.5%, were investigated. Stability was evaluated in heparinized whole blood for 24 h at +4°C, in plasma for 8 weeks at –25°C and in sulfuric acid for 6 months at –25°C.

Results: Mean recovery rates were between 96.4% and 102.6% in all local anesthetics and media. No statistical significance became obvious for differences between recovery rates and initial values.

Conclusion:Stability of prilocaine, mepivacaine, lidocaine and bupivacaine can be expected when samples are stored as heparinized whole blood for 24 h at +4°C, plasma for 8 weeks at –25°C, and after preparation into sulfuric acid for 6 months at –25°C.
Distribution, tolerability and tissue compatibility of intrathecal tizanidine in the sheep
Authors: Ochs G. , Loew M. , Tonn J. , Toyka K.
Published: January 2009

Background: Tizanidine (TZD) is an alpha‐2‐adrenergic drug with potential spinal analgesic action and could be a substitute or additive for intrathecal (i.t.) opiates in chronic pain treatment. However, long‐term tolerability and tissue compatibility are not yet established.

Methods: Three sheep were infused intrathecally with TZD up to 4000 μg/d over a time period of up to 440 d using implantable drug administration devices; one control animal was infused with vehicle only; standard values were collected from untreated sheep. CSF samples and blood samples were analyzed to determine pharmacokinetics and systemic redistribution. Behavioral effects were studied. The spinal cord tissue was investigated using standard laboratory histology.

Results: Bolus kinetics after i.t. injection of TZD are best described by a two‐phase model. Elimination half‐lives of TZD in CSF were 15 min and 152 min, respectively. Clearance of TZD from lumbar CSF was 0.48 ml/min. Doses higher than 500 μg i.t. caused dose‐dependent motor inactivity and sleepiness. Continuous i.t. TZD up to 4 mg/d was well tolerated regarding behavior, physical activity, heart rate, muscle strength, and coordination. Minor elevations of CSF cell counts and total protein were detected both in saline and TZD‐treated animals, presumably due to local irritation by the catheter and repeated sampling procedures. Histological evaluation of the spinal cord and adjacent tissues showed no abnormalities.

Conclusion: The long‐term intrathecal infusion of TZD is well tolerated and non‐toxic in the sheep. The data favor clinical trials in patients with chronic pain.
Retracted: Modified double burst stimulation at varying stimulating currents
Authors: Saitoh Y. , Fujii Y. , Makita K. , Tanaka H. , Amaha K.
Published: January 2009

The above article, published on August 1998 in Wiley Online Library (http://wileyonlinelibrary.com) and in Volume 42, pp. 851‐857, has been retracted by agreement between the authors, the journal Editor‐in‐Chief, Professor Michael Haney and John Wiley and Sons Ltd. The retraction has been agreed due to the lead author's declaration that official permission from the Ethical Committee of the Faculty of Medicine, Tokyo Medical and Dental University was not sought and therefore was not granted for this study.

REFERENCE

Saitoh Y, Fujii Y, Makita K, Tanaka H, Amaha K. Modified double burst stimulation of varying stimulating currents. Acta Anaesthesiol Scand. 1998;42(7):851‐857.
Brachial plexus injury during cardiac catheterisation in children: Report of two cases
Authors: Neto E. P. Souza , Durand P. G. , Sassolas F. , Vial C. , Lehot J. J.
Published: January 2009

The arm is particularly vulnerable to neurological injury, due to the intimate anatomical relationship between the brachial plexus and the traction zones. Severe injuries of the brachial plexus can be caused by compression, traction or laceration. Fortunately, many deficits are superfial and permanent neurovascular deficits are rare. Nevertheless, it is important to identify the probable cause of the injury since the prognosis for recovery directly depends on the underlying nature of the neurological deficit. Two anaesthetised children who suffered brachial plexus injury during cardiac catheterisation are reported. The first, with Ebstein's anomaly and significant pulmonary valve stenosis, presented, after the procedure, with a right arm motor deficit with proximal predominance. The second patient, with tetralogy of Fallot and pulmonary atresia, presented difficulty in left arm abduction and external rotation on awakening.

The risk factors for brachial plexus lesions during anaesthesia are discussed. These include improper positioning, anaesthetic agents, extreme variations of body mass index and anatomical anomalies. Prevention, evolution and treatment of the brachial plexus injury are also considered. With proper care by the cardio‐radiologist and anaesthesiologist the frequency of this injury can be reduced.
Adrenaline markedly improves thoracic epidural analgesia produced by a low‐dose infusion of bupivacaine, fentanyl and adrenaline after major surgery: A randomised, double‐blind, cross‐over study with and without adrenaline
Authors: Niemi G. , Breivik H.
Published: January 2009

Background:Basic pharmacological research indicates that there are synergistic antinociceptive effects at the spinal cord level between adrenaline, fentanyl and bupivacaine. Our clinical experience with such a mixture in a thoracic epidural infusion after major surgery confirms this. The objectives of the present study were to evaluate the effects on postoperative pain intensity, pain relief and side effects when removing adrenaline from this triple epidural mixture.

Methods:A prospective, randomised, double‐blind, cross‐over study was carried out in 24 patients after major thoracic or abdominal surgery. Patients with only mild pain when coughing during a titrated thoracic epidural infusion of about 10 ml · h−1of bupivacaine 1 mg · ml−1, fentanyl 2 μg · ml−1, and adrenaline 2 μg · ml−1were included. On the 1stand 2ndpostoperative days each patient was given a double‐blind epidural infusion, at the same rate, with or without adrenaline. The effect was observed for 4 h or until pain when coughing became unacceptable in spite of a rescue analgesic procedure. Rescue analgesia consisted of up to two epidural bolus injections per hour and i.v. morphine if necessary. All patients received rectal paracetamol 1 g, every 8 h. Fentanyl serum concentrations were measured with a radioimmunoassay technique at the start and end of each study period. Main outcome measures were extent of sensory blockade and pain intensity at rest and when coughing, evaluated by a visual analogue scale, a verbal categorical rating scale, the Prince Henry Hospital pain score, and an overall quality of pain relief score.

Results:The number of hypaesthetic dermatomal segments decreased (P<0.001) and pain intensity at rest and when coughing increased (P<0.001) when adrenaline was omitted from the triple epidural mixture. This change started within the first hour after removing adrenaline. After 3 h pain intensity when coughing had increased to unacceptable levels in spite of rescue analgesia (epidural bolus injections and i.v. morphine). Within 15–20 min after restarting the triple epidural mixture with adrenaline, pain intensity was again reduced to mild pain when coughing. Serum concentration of fentanyl doubled from 0.22 to 0.45 ng · ml−1(P<0.01), and there was more sedation during the period without adrenaline.

Conclusions:Adrenaline increases sensory block and improves the pain‐relieving effect of a mixture of bupivacaine and fentanyl infused epidurally at a thoracic level after major thoracic or abdominal surgery. Serum fentanyl concentrations doubled and sedation increased when adrenaline was removed from the epidural infusion, indicating more rapid vascular absorption and systemic effects of fentanyl.
Prevention of nausea and vomiting with granisetron, droperidol and metoclopramide during and after spinal anaesthesia for caesarean section: A randomized, double‐blind, placebo‐controlled trial
Authors: Fujii Y. , Tanaka H. , Toyooka H.
Published: January 2009

Background: Nausea and vomiting during and after spinal anaesthesia for caesarean section are distressing to the patient. This study was undertaken to evaluate the efficacy and safety of granisetron, droperidol and metoclopramide for the prevention of nausea and vomiting in parturients undergoing caesarean section under spinal anaesthesia.

Methods: In a randomized, double‐blind, placebo‐controlled trial, 120 patients received granisetron 3 mg, droperidol 1.25 mg, metoclopramide 10 mg or placebo (saline) (n=30 of each) i. v. immediately after clamping of the foetal umbilical cord. Nausea, vomiting and safety assessments were performed during and after spinal anaesthesia for caesarean section.

Results: The incidence of intraoperative, post‐delivery nausea and vomiting was 13%, 17%, 20% and 63% after administration of granisetron, droperidol, metoclopramide and placebo, respectively; the corresponding incidence during 0–3 h after surgery was 7%, 27%, 27% and 43%; the corresponding incidence during 3–24 h after surgery was 7%, 20%, 23% and 37% (P<0.05; overall Fisher's exact probability test). No clinically important adverse events were observed in any of the groups.

Conclusion: Granisetron is highly effective for preventing nausea and vomiting during and after spinal anaesthesia for caesarean section. Droperidol and metoclopramide are effective for the prevention of intraoperative, post‐delivery emesis, but are ineffective for the reduction of the incidence of postoperative emesis.
Slow injection of local anaesthetic will decrease pain during dorsal penile nerve block
Authors: Serour F. , Mandelberg A. , Mori J.
Published: January 2009

Purpose: To evaluate whether a very slow injection of local anaesthetics during dorsal penile nerve block for circumcision causes less pain than a more rapid injection.

Methods: In a prospective, double‐blind, randomized study, 75 patients aged 15 to 53 yr (mean±SD=22±8.4 yr) were randomized into two groups. A solution of 2% lidocaine, 1 mg . kg−1, and 0.5% bupivacaine, 0.5 mg . kg−1 without epinephrine to a maximum dose of 10 ml was injected using either a very slow rate (injection time 100 to 150 s, Group A) or a faster rate (injection time 40 to 80 s, Group B). Patients were questioned regarding pain by a physician who was blinded to the mode of therapy. Pain was rated as 1) mild (negligible), 2) moderate (non‐negligible, but easily endurable), 3) intense (but endurable) and 4) total refusal to continue.

Results: A significant pain score difference was found between Groups A and B (median=l vs. 2, P=0.0006) as well as a significant correlation between pain score and the rate of infiltration (rs= –0.394, P<0.0001).

Conclusions: Slow injection is an important factor in reducing pain during penile block.
Does lidocaine protect the heart during coronary revascularisation?
Authors: Rinne T. , Kaukinen S.
Published: January 2009

Background: Lidocaine has been used as the primary antiarrhythmic agent for ventricular arrhythmias during acute myocardial infarction (MI) and open heart surgery. Its cardioprotective effects have been studied in experimental settings and also during angioplastic reperfusion and coronary revascularisation. The basic mechanism of action, probably also involved with cardioprotection, has been demonstrated to be blockade of cardiac sodium channels. In this open study we investigated the contribution of continuous lidocaine infusion to cardioprotection during coronary revascularisation with blood cardioplegia.

Methods: During coronary revascularisation with cold blood cardioplegia, a study group of 50 patients received a prophylactic lidocaine infusion for 20 h started with a bolus dose before aortic clamping; another group of 50 patients without the infusion served as a control group. Serum troponin T concentration, serum creatine kinase MB activity and electrocardiography were the main parameters recorded.

Results: Serial measurement of Troponin T (P=0.06) and CK‐MB values: (P=0.09) were slightly lower in the lidocaine group, but the differences were not statistically significant.

Conclusion: Lacking statistically significant evidence of improved cardioprotection, lidocaine infusion cannot be recommended as a routine treatment during coronary revascularisation.
Retracted: Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery
Authors: Boldt J. , Papsdorf M. , Piper S. , Padberg W. , Hempelmann G.
Published: January 2009

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties.

Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro‐ and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg−1 · min−1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin‐1 (ET‐1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day.

Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min−1 · m−2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO2I) and oxygen consumption index (VO2I) were also significantly increased in the dopexamine group (DO2I: from 416±91 to 717±110 ml/m2 · m2; VO2I: from 98±25 to 157±22 ml/m2 · m2), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET‐1: from 2.88±0.91 to 6.91±1.20 pg/ml).

Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.
Mivazerol inhibits intrathecal release of glutamate evoked by halothane withdrawal in rats
Authors: Zhang X. , Kindel G. , Wülfert E. , Hanin I.
Published: January 2009

Background: Mivazerol is a new and selective α2‐adrenergic receptor agonist devoid of hypotensive effects (1, 2). Previous studies have demonstrated that mivazerol prevents hemodynamic instability during emergence from halothane anesthesia in rats (3). The present study was to determine whether glutamate and aspartate are involved in this action of mivazerol, at the second to third thoracic segments (T2–T3) of the spinal cord.

Methods:In vivomicrodialysis in combination with high‐performance liquid chromatography (HPLC) was employed in the study. Blood pressure (BP) and heart rate (HR) were recorded along with intrathecal (i.t.) microdialysis perfusion.

Results: BP, HR and i.t. release of glutamate (GLU, pmol/μl) were stable in the rats under 1.1% halothane anesthesia. However, halothane withdrawal immediately increased BP, HR, and i.t. release of GLU, and remained elevated for at least 2 h after withdrawal of halothane. Thirty minutes prior to halothane withdrawal, intravenous (i.v.) infusion of mivazerol (15 μg · kg–l· h–) almost completely prevented the increases in HR (Δ18±7 vs Δ79±7 beats/min), and in the i.t. release of GLU (Δ10.3±3.7 vs Δ30.6±5.9; 112% vs 167%). Local i.t. microinjection of mivazerol (2.5 μg/kg) 2 min prior to withdrawal of halothane also blocked the HR responses, as well as on the i.t. release of GLU following halothane withdrawal.

Conclusion: The present study demonstrates that emergence from halothane anesthesia increases i.t. release of GLU, and that mivazerol has an inhibitory effect on the above, through its direct action on the spinal cord.
High thoracic/low cervical, long‐term intrathecal (IT) infusion of bupivacaine alleviates “refractory” pain in patients with unstable angina pectoris: Report of 2 cases
Authors: Dahm P. , Nitescu P. , Appelgren L. , Curelaru I.
Published: January 2009

Background: There is no reliable treatment for “refractory” pain from unstable angina pectoris (UAP) when epidural infusion of bupivacaine has failed to relieve it. In two such cases we explored the potential of intrathecal (IT) bupivacaine infusion to provide pain relief.

Patients and methods: Two female patients, 70 and 67 years. An 18‐G nylon catheter was inserted intrathecally through a 17‐G Tuohy needle via the T2–T3 interspace and its tip located at the height of C6–C7 vertebrae. The catheter was connected to a portable, programmable electronic pump filled with bupivacaine 5 mg/ml. The infusion started at rates of 0.1–0.2 ml/h, with optional bolus doses of 0.1–0.2 ml, 4–2 times/h, respectively, by PCA (Patient‐ControlledAnalgesia), and then adjusted to give the patients satisfactory (80%–100%) pain relief.

Results: Pain relief was obtained with doses of IT‐bupivacaine ranging from 17 to 45 (mean=25) mg/d. The pain intensity decreased from VAS (VisualAnalogueScore) 9–10 to 0–2 out of 10. The nocturnal sleep improved from 2–4 to 6–7 h. The patients could now ambulate, walking or in a wheel‐chair. The IT‐treat‐ment lasted 700 and 437 d, of which 540 and 343 d (respectively) were spent at home, and was terminated by: (a) the patient's death due to intracranial bleeding (1st case); (b) progressive aggravation of the unstable angina that could not be fully countered by increasing the bupivacaine dose above 1.0 mg/h due to occurrence of cerebral transient ischemic attacks, usually not correlated with orthostatic arterial hypotension but apparently facilitated by microembolization of the cerebral arteries (2nd case).

Conclusion: IT‐bupivacaine infusion may alleviate “refractory” pain in patients with unstable angina pectoris when epidural bupivacaine failed to do so. Its use is apparently limited by the IT‐bupivacaine critical dosage (in these patients = 1.0–1.5 mg/h).
A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits
Authors: Tateishi T. , Watanabe M. , Nakura H. , Tanaka M. , Kumai T. , Aoki T. , Kobayashi S.
Published: January 2009

Background:Halothane inhibitsin vitroandin vivoactivity of cytochrome P‐450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit thein vivoactivity of CYP2E1.

Methods:We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.

Results:All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.

Conclusions:At therapeutic concentrations, thein vivoinhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.