bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of intrathecal morphine, clonidine and baclofen on allodynia after partial sciatic nerve injury in the rat
Authors: Hao J.‐X. , Xu I. S. , Xu X.‐J. , Wiesenfeld‐Hallin Z.
Published: March 2003

Background: Increased response to mechanical or cold stimulation of hind paws was observed in rats with partial sciatic nerve injury as a result of photochemically induced ischemia. The present study examined the effects of intrathecal morphine, clonidine and baclofen on the allodynia‐like responses.

Methods: The left sciatic nerves of rats were irradiated for 2 min with an argon ion laser under chloral hydrate anesthesia. The threshold of paw withdrawal to mechanical stimulation was determined with a series of monofilaments (von Frey hairs). The response to cold stimulation was tested by spraying ethyl chloride on the plantar surface of the paw. When rats were exhibiting stable mechanical and cold allodynia‐like behaviors after nerve injury, the effects of i.t. morphine (1, 2, 7 μg), clonidine (1, 2, 7 μg) and baclofen (0.1, 0.2, 0.7, 9 μg) in a cumulative dose regime were investigated.

Results: Intrathecal morphine dose‐dependently alleviated the mechanical and cold allodynia without inducing motor impairment or sedation. Intrathecal clonidine did not alter the response of hind paws to mechanical stimulation, but reduced the cold allodynia. Intrathecal baclofen reduced the responses of rats to mechanical stimulation only at doses that also induced profound motor deficits.

Conclusions: The present data suggest that intrathecal morphine, and to some extent clonidine, but not baclofen, alleviated the abnormal pain‐related behaviors in this new rat model of partial peripheral nerve injury. Differences in the pharmacological profile between the present model and other models of peripheral nerve injury are discussed.
Spinal cord morphology after chronic intrathecal administration of adenosine in the rat
Authors: Rane K. , Karlsten R. , Sollevi A. , Gordh Jr T. , Svensson B. A.
Published: March 2003

Background: The endogenous compound adenosine is known to have various modulatory effects both in the peripheral and central nervous system. Adenosine and its analogues induce anti?no?ci?ception in animal models when administrated systemically and intrathecally (IT), both in acute and chronic models of pain. Before a new drug is introduced for spinal pain treatment in humans, experimental studies of neurotoxicity must be undertaken.

Methods: This study was performed in rats in order to reveal morphological or morphometric signs of spinal cord damage after chronic (two weeks) administration of adenosine. After insertion of IT catheters, the animals were injected twice a day during two weeks with adenosine (100 μg) or saline (controls). Potential spinal neurotoxicity was evaluated morphologically by light and electron microscopy supplemented by a morphometric analysis.

Results: There were no signs of histologic changes indicating neurotoxic effects by any of the methods of analysis. The morphological findings in the adenosine treated rats did not differ in any case from those of the saline treated animals.

Conclusion: The results suggest that chronic IT administration of a high dose of adenosine is not associated with neurotoxicity in the rat spinal cord.
Day‐case laparoscopy: a comparison of prophylactic opioid, NSAID or local anesthesia for postoperative analgesia
Authors: Salman M. A. , Ercan Yücebaş M. , Coşkun F. , Aypar Ü.
Published: March 2003

Background: The study was aimed to evaluate the analgesic efficacy, postoperative comfort, recovery characteristics and side effects of three different analgesic agents administered prophylactically.

Methods: Eighty patients undergoing day‐case minor operative laparoscopy were randomly allocated into four groups to receive tenoxicam 20 mg i.v. (Group T), fentanyl 100 μg i.v. (Group F), 5 ml of bupivacaine 2.5 mg/ml for infiltration of trocar sites (Group B), 30, 10 and 5 min before incision respectively. Bupivacaine, 35 ml, 2.5 mg/ml was also administered into the pelvic cavity in Group B. Group P received only placebo. Postoperative pain, analgesic requirements, first response to verbal stimulus, first analgesic requirement, ability to walk without help, to drink and to void, blood pressures, SpO2 and respiration rates were recorded in the PACU. Postoperative pain was evaluated by verbal rating scale. Pain scores, analgesic requirements and side effects were evaluated by telephone calls until the 48th postoperative hour.

Results: Postoperative pain scores were lower and time to requirement of rescue analgesics was longer in groups F and B compared to Group P. In the PACU, analgesic requirements were lower in Group B, compared to Group P. Nausea and vomiting were increased in Group F.

Conclusion: Tenoxicam 20 mg i.v. was found to be ineffective whereas bupivacaine was superior to other groups in reducing pain and analgesic requirements. Bupivacaine also increased time to first analgesics and obtained better recovery characteristics, underlining its value in prophylactic pain management compared to the other two agents.
No difference between bupivacaine in 0.9% and 8% glucose for spinal anaesthesia in small children
Authors: Kokki H. , Hendolin H.
Published: March 2003

Background: Baricity is one of the most important factors to influence the characteristics of distribution of the local anaesthetic and hence success and spread of the blockade. Bupivacaine is rendered hyperbaric by adding glucose. The effect of differing degrees of hyperbaricity remains to be evaluated.

Methods: Two hyperbaric bupivacaine solutions, in 0.9% and in 8% glucose, for spinal anaesthesia were investigated in 60 children, aged 1–7 years, in a double‐blind, randomised, parallel group, prospective study. The children were premedicated with diazepam orally. Bupivacaine 5 mg ml−1 in either 0.9% or 8% glucose was injected in a dose of 0.4 mg kg−1. Maximum cephalad extent and regression of sensory block were tested by transcutaneous electrical stimulation.

Results: Success rate, spread and duration of sensory block were similar in both groups. Only one child required a single dose of fentanyl during surgery. The highest median level of sensory block was T3 (T2–T7) (median (10th/90th percentiles)) in both groups. Time to reach T10 did not differ between the groups. The incidence of adverse effects was similar. Atropine was administered to one child in each group to treat bradycardia and 6 children (10%) experienced shivering. One child in each group vomited once.

Conclusion: These results demonstrate that bupivacaine in 0.9% glucose and in 8% glucose solutions are equally suitable for spinal anaesthesia in small children. Similar success rate, spread and duration of the sensory and motor block are achieved with both baricities of bupivacaine.
Effect of i.v. tenoxicam during caesarean delivery on platelet activity
Authors: Elhakim M. , Fathy A. , Amine H. , Saeed A. , Mekawy M.
Published: March 2003

Background: Non‐steroidal anti‐inflammatory drugs inhibit platelet aggregation and prolong bleeding time in healthy subjects. We have studied the effect of i.v. tenoxicam during caesarean delivery on skin bleeding time, operative, and postoperative blood loss, and beta‐thromboglobulin and platelet factor 4 as specific molecular markers for platelet activity.

Methods: Fifty women were studied. Twenty‐five were given tenoxicam 20 mg i.v. 10 min before induction of general anaesthesia, and 25 formed a control group. Skin bleeding time and platelet markers were determined the day before and 1 h after induction of anaesthesia.

Results: In the tenoxicam group, there was an slight increase in skin bleeding time with no statistically significant changes in platelet marker levels. In the control group, platelet markers increased 1 h after surgery. The surgeon's assessment of uterine relaxation, using a visual analogue score, operating theatre blood loss, and the frequency of bleeding over 24 h after operation, showed no significant difference between the two groups.

Conclusion: During caesarean delivery i.v. tenoxicam causes a slight increase in bleeding time with no significant changes in platelet marker levels.
The effect of dopexamine on regional tissue oxygenation, systemic inflammation and amino acid exchange in major abdominal surgery
Authors: Suojaranta‐Ylinen R. T. , Ruokonen E. T. , Takala J. A.
Published: March 2003

Background: Beta‐adrenergic agents are frequently used to improve cardiac performance in surgical and intensive care patients. Beta‐adrenergic agents have metabolic and anti‐inflammatory effects in addition to their cardiovascular effects. Splanchnic metabolic activity increases in response to surgery and inflammation. Dopexamine is believed to favor blood flow distribution to the splanchnic region.

Methods: We investigated the effect of dopexamine, started before major abdominal surgery, on postoperative patterns of systemic and regional blood flow, metabolic response, and markers of inflammation. Twenty‐one patients undergoing major abdominal surgery were studied. All patients were stabilized preoperatively to predefined hemodynamic endpoints with fluids. After preoperative measurement of systemic and splanchnic oxygen transport and splanchnic lactate, glutamine and alanine exchange and blood levels of tumor necrosis factor (TNF) and interleukin‐6 (IL‐6), the patients were randomized to receive an infusion of dopexamine at 0.5 μg kg−1 min−1 (group 1) or 2.0 μg kg−1 min−1 (group 2) or placebo. Measurements were repeated at 6 h and 24 h after the end of the operation and the blood levels of cytokines also at 36 h postoperatively.

Results: Dopexamine evoked an increase in cardiac index preoperatively. Postoperatively, there was no difference between the groups in systemic and regional hemodynamics or oxygen transport: cardiac index, splanchnic blood flow and oxygen delivery increased similarly in each group. Accordingly, systemic oxygen extraction decreased. Glutamine, alanine and lactate exchange did not differ between the groups. The only metabolic change was an increased splanchnic uptake of alanine, which also was unaffected by dopexamine. There was no difference between the groups in TNF and IL‐6 levels; TNF level did not change, while IL‐6 level increased in response to surgery.

Conclusions: Dopexamine, when added to a preoperative stabilization protocol with fluids, did not augment the postoperative hemodynamic response, and had no effect on postoperative metabolic and inflammatory responses.
Evaluation of pressure/volume loops based on intratracheal pressure measurements during dynamic conditions
Authors: Kárason S. , Søndergaard S. , Lundin S. , Wiklund J. , Stenqvist O.
Published: March 2003

Background: The aim of this study was to evaluate and compare information about lung mechanics obtained by dynamic pressure/volume loops based on Y‐piece and intratracheal airway pressure.

Methods: Airway pressure was measured simultaneously at the Y‐piece and trachea. Flow/tidal volume was measured by side‐stream spirometry at the Y‐piece. The effect of an intraluminal catheter in the tube was evaluated in a lung model. Ten adults with acute lung injury and mechanical ventilation were studied. Measurements were performed during volume‐(VC) and pressure‐controlled (PC) ventilation at different ventilator settings.

Results: Lung model: There was a statistically significant difference (P<0.001) between trachea and Y‐piece pressure/volume loop areas during both VC and PC ventilation. The ratio trachea area/Y‐piece area decreased with increased endotracheal tube resistance (r=0.96). Patients: The difference between trachea and Y‐piece P/V‐loops was statistically significant at all 21 ventilatory settings (P<0.05–0.001). The tracheal loop revealed clearly intrinsic PEEP and lowered compliance during overinflation, which was difficult or impossible to see in the Y‐piece pressure/volume loop.

Conclusion: By measuring airway pressure at the trachea the effect of endotracheal tube resistance during inspiration is excluded while it is included during expiration, yielding correct end‐points of inspiration and expiration. This makes it possible to calculate accurately total compliance of the respiratory system during dynamic conditions. By monitoring of airway pressure in the trachea, respiratory mechanics can be assessed more accurately and ventilatory settings adjusted to attenuate ventilator induced lung injury.
Cardiac troponin I is reliable with immediate but not medium‐term cardiac complications after abdominal aortic repair
Authors: Godet G. , Dumerat M. , Baillard C. , Ben Ayed S. , Bernard M.‐A. , Bertrand M. , Kieffer E. , Coriat P.
Published: March 2003

Background: The diagnosis of cardiac complications is particularly challenging in the postoperative course of non‐cardiac surgery. Follow‐up of patients suggests that silent or symptomatic postoperative myocardial infarction have similar short‐term outcomes. Cardiac troponin I (cTnI) has been reported as being a sensitive and specific marker of these complications.

Methods: We conducted a prospective study to determine the cut‐off values of cTnI which may predict cardiac complications, i: in the postoperative period until discharge, and ii: during a 1‐year period after aortic surgery. Three hundred and twenty‐nine consecutive patients undergoing infrarenal aortic surgery were included over a 2‐year period in a single center. cTnI was measured at recovery and on the 1st, 2nd and 3rd postoperative days. The presence or absence of cardiac complications was classified by reviewers who had no knowledge of cTnI. For evaluation of the ideal discrimination value of cTnI between the complicated and uncomplicated patient groups, we calculated receiver‐operator characteristics for the mean values of the peak of cTnI.

Results: Thirteen patients (4%) developed 19 postoperative cardiac complications. Thirteen patients (4%) died in the postoperative period. Nine patients (3%) developed 10 cardiac complications during the 1‐year follow‐up in 316 patients. In 280 patients, cTnI was below 0.5 ng/ml, in 22 patients between 0.5 and 1.5 ng/ml and the 27 remaining patients had a cTnI higher than 1.5 ng/ml. The area under the curve for postoperative cardiac complications was 0.84 (SD=0.21). A limit value of 0.54 ng/ml yielded a sensitivity of 75% and a specificity of 89%. The area under the curve for late cardiac complications was 0.45 (SD=0.13).

Conclusion: A cTnI level greater than 0.54 ng/ml appears to be correlated with the occurrence of cardiac complications in the period until discharge, but no value of cTnI is predictive of late cardiac complications occurring in the 1st year after aortic surgery.
Lipid peroxidation induced by an early inflammatory response in endotoxaemia
Authors: Basu S. , Eriksson M.
Published: March 2003

Background: Endotoxaemic challenge promptly causes lipid peroxidation. Porcine endotoxaemia can be used to replicate severe human septic shock. This model was used to evaluate non‐enzymatic [8‐Iso‐prostaglandin F2α (8‐Iso‐PGF2α)] and enzymatic [15‐keto‐13,14‐dihydro‐prostaglandin F2α (15‐K‐DH‐PGF2α)] lipid peroxidation, respectively, in relation to survival. The aim of this study was to correlate, if possible, pathophysiologic events during endotoxaemia to the levels of these arachidonic acid metabolites.

Methods: Nineteen pigs were anaesthetised, monitored (circulatory and respiratory variables in relation to lipid peroxidation) and given a continuous 6 h E. coli endotoxin (10 μg · kg−1 · h−1) infusion. All animals were mechanically ventilated at constant tidal volumes and the inspired oxygen fraction was kept constant during the experimental period.

Results: This endotoxin infusion caused expressed derangements in all pigs and death in 9 of them. The levels of 8‐Iso‐PGF2α, indicating oxidative injury, were different in time course, magnitude and fashion between survivors and non‐survivors. The levels of 15‐K‐DH‐PGF2α, indicating inflammatory response, showed a similar pattern. At 1 h the CO2 partial pressure in arterial blood was significantly higher in non‐surviving pigs and correlated (r: 0.7; P<0.05) to the levels of 15‐K‐DH‐PGF2α. Prostaglandin F2α is mainly metabolised in the lung. The lung weights were significantly (P<0.05) higher in non‐surviving than in surviving animals. Both free radical and cyclooxygenase catalysed oxidative modification occurs during endotoxaemia.

Conclusion: Increased metabolism and inflammation, as evaluated by 15‐K‐DH‐PGF2α, in the group of non‐survivors may mediate the increase in arterial CO2. Thus, increased lipid peroxidation seems to be associated with endotoxaemic organ dysfunction and increased mortality.
Effects of melagatran, an inhibitor of thrombin, on fibrin deposits, haemodynamics, and platelet count in endotoxaemic pigs
Authors: Eriksson M. , Saldeen T. , Mattsson C. , Larsson A.
Published: March 2003

Background: Thrombin plays a pivotal role in the development of septic shock. Porcine endotoxaemia can replicate this condition. We wanted to evaluate whether melagatran, a novel inhibitor of thrombin, would counteract some of the endotoxin‐induced changes in this model.

Methods: Fifteen pigs were anaesthetised, monitored (circulatory and respiratory variables) and subjected to an infusion of E. coli endotoxin at 10 μg  ·  kg−1  ·  h−1. Six pigs were given melagatran during the first 3 h of the 6‐h endotoxaemic period. Nine controls were given the corresponding volume of saline instead of melagatran. Specimens from the liver and the left lung were taken for light microscopy post mortem.

Results: The endotoxin‐induced increase in pulmonary capillary wedge pressure and drop in platelet count were significantly less pronounced in the melagatran‐treated pigs. Deposits of pulmonary fibrin were significantly reduced in the melagatran group, without improving oxygenation. Light microscopy revealed no hepatic fibrin in the pigs treated with melagatran in contrast to the endotoxaemic controls. Hepatic neutrophil accumulation was reduced in the melagatran group as compared to controls. Hepatocellular degeneration and plasma levels of tumour necrosis factor α (TNFα) and bilirubin were of the same magnitude in both groups.

Conclusion: Melagatran reduced pulmonary capillary wedge pressure, a retrograde reflection of the left ventricular end‐diastolic filling pressure, and also pulmonary stasis in pigs subjected to endotoxaemic challenge. Pulmonary and hepatic fibrin depositions were reduced, but PaO2 levels or liver function markers were not affected by melagatran during the early phase of endotoxaemia. Obstruction of the intrahepatic bile ducts, by fibrin depositions, is not responsible for reduced excretion of conjugated bilirubin during endotoxaemia. The beneficial effects of melagatran during endotoxaemia were not due to any reduction of plasma TNFα.
Continuous epidural analgesia with bupivacaine‐fentanyl versus patient‐controlled analgesia with i.v. morphine for postoperative pain relief after knee ligament surgery Note
Authors: Silvasti M. , Pitkänen M.
Published: March 2003

Background: Both epidural analgesia and intravenous patient‐controlled analgesia (PCA) have been found efficacious after various types of surgery. We compared the efficacy, safety, side effects and patient satisfaction of these methods in a randomized double‐blind fashion after elective anterior cruciate ligament reconstruction of the knee.

Methods: Fifty‐six patients had an epidural catheter placed at the L2–L3 interspace. Spinal anaesthesia with 15 mg of plain bupivacaine 5 mg/ml was performed at the L3–L4 interspace. After surgery the patients were randomly divided into three groups: 19 received a continuous epidural infusion with bupivacaine 1 mg/ml and fentanyl 10 mg/ml (F10), 19 patients received bupivacaine 1 mg/ml and fentanyl 5 μg/ml (F5) and 18 patients received saline (S). The rate of the epidural infusions was 0.1 ml kg−1h−1. Each patient could also use an intravenous (i.v.) PCA device with 40 μg/kg bolus doses of morphine with a lockout period of 10 min and a maximum dose 240 μg kg−1h−1. At the end of surgery ketoprofen 100 mg i.v. was given and continued orally three times a day. Patients were assessed for pain with a visual analogue scale (VAS) at rest and during activity, side effects and satisfaction at 3, 9 and 20 h.

Results: Both epidural infusions (F10, F5) provided better analgesia than epidural saline plus i.v. PCA (S) (P<0.05). There was slightly less nausea in the S group (NS). In spite of the difference in the quality of pain relief, there was no difference between the groups in patient satisfaction regarding analgesic therapy.

Conclusion: Epidural infusion of fentanyl (1 μg kg−1h−1 or 0.5 μg kg−1h−1) and bupivacaine (0.1 mg kg−1h−1) provided better pain relief but more side effects than intravenous morphine patient‐controlled analgesia after knee ligament surgery. Almost all patients in all groups were satisfied with their pain relief.
Note
Patient‐controlled versus nurse‐controlled pain treatment after coronary artery bypass surgery
Authors: Pettersson P. , Anjou Lindskog E. , Öwall A.
Published: March 2003

Background: Pain after coronary artery bypass surgery persists for several days. A continuous intravenous infusion of an opioid adequately accomplishes good pain control in the intensive care unit, but it is often not suitable on the ordinary ward. Patient‐controlled analgesia (PCA) with intermittent injections delivered by one of the new devices now available could be an alternative to conventional nurse‐controlled analgesia (NCA) based on intermittent injections. The aim was to compare these two techniques with respect to efficacy and the amount of opioid used.

Methods: Forty‐eight patients randomly received PCA or NCA with ketobemidone following extubation after coronary artery bypass grafting. Drug consumption, pain assessment with the visual analogue score (VAS) and possible side effects were evaluated from extubation to the end of the second postoperative day.

Results: On the day of surgery the VAS scores did not differ between the groups. From the afternoon of the first postoperative day the VAS scores were higher in the NCA group with mean values at 3–4 out of 10 as compared with mean values around 2 in the PCA group (P<0.01). During the study period the patients in the PCA group received more ketobemidone as compared with the NCA group, 61.9±24.0 mg and 36.3±20.2 mg, respectively (P<0.01). Additional oral analgesics were used in 12 of the patients in the NCA group compared with none in the PCA group. The few side effects reported were equally distributed between the two groups.

Conclusion: PCA treatment after coronary artery bypass surgery resulted in better pain treatment and the use of more opioid without an increase in side effects compared with traditional NCA treatment.
Pain intensity and pain relief after surgery
Authors: Klopfenstein C. E. , Herrmann F. R. , Mamie C. , Van Gessel E. , Forster A.
Published: March 2003

Background: Postoperative pain remains a problem for many patients. One of the reasons could lie in the insufficient evaluation of pain and analgesia. This study was designed to obtain more insight in the performance of nurses and physicians in evaluating patients’ postoperative pain and pain relief.

Methods: Forty patients hospitalised in one surgical unit and the 8 nurses and the 2 surgical residents in charge of this unit were investigated. Patients were asked to assess on a visual analogue scale the intensity of their pain and their pain relief at rest, on coughing and globally since the operation, on the first and second postoperative days and the day before hospital discharge. Separately, the nurses and the physicians were asked to evaluate the pain intensity and the pain relief for each patient involved. A MANOVA and a multiple comparisons test with Bonferroni adjustment were used.

Results: At rest, only nurses underestimated pain intensity on the day before hospital discharge. On coughing, physicians underestimated pain intensity in all 3 assessments, whereas nurses only in the 3rd assessment (on the day before hospital discharge). Globally, physicians underestimated pain intensity in all 3 assessments, nurses in the 2nd and the 3rd assessment. Only physicians overestimated pain relief on coughing on the day before hospital discharge and globally in all 3 assessments. Surprisingly, the pain scores rated by the patients before hospital discharge were high.

Conclusion: The results of this survey suggest that assessment of pain and pain relief is inadequately done by both physicians and nurses. This emphasises the importance of a better training, and a systematic assessment of pain intensity and pain relief.
Nitric oxide does not play a major role in the regulation of systemic hemodynamic responses to acute normovolemic hemodilution
Authors: Hirose Y. , Kimura H. , Kitahata H. , Kawahito S. , Oshita S.
Published: March 2003

Background: The mechanisms of cardiovascular changes following acute normovolemic hemodilution (ANH) have not been fully elucidated. We tested the hypothesis that inhibition of nitric oxide synthesis attenuates ANH‐induced cardiovascular responses.

Methods: We observed the effects of Nω‐nitro‐L‐arginine methyl ester (L‐NAME) pretreatment on ANH‐induced cardiovascular responses and compared these effects with those elicited by phenylephrine (PHE). Twenty dogs anesthetized with isoflurane were divided into two groups: one group was pretreated with L‐NAME and the other with PHE. Both groups were normovolemically hemodiluted using 6% hydroxyethyl starch to reduce the hemoglobin concentration to approximately 50% of the pretreatment value.

Results: Pretreatment with either L‐NAME or PHE caused a significant increase in mean aortic blood pressure (MAP) and systemic vascular resistance (SVR) with a significant decrease in cardiac output (CO) and stroke volume (SV). However, no remarkable differences in these variables were seen between groups. In both groups ANH produced increases in heart rate, CO, SV, and maximal left ventricular dP/dt with a significant decrease in SVR. No significant differences in these variables were apparent after ANH except that MAP was decreased in the PHE group but not in the L‐NAME group.

Conclusion: Our results suggest that nitric oxide does not play a major role in mediation or modulation of the systemic vascular responses to ANH.
Haemodynamic effects of intravenous clonidine on propofol or thiopental induction
Authors: Marinangeli F. , Cocco C. , Ciccozzi A. , Ciccone A. , Donatelli F. , Facchetti G. , Paladini A. , Pasqualucci A. , Varrassi G.
Published: March 2003

The study evaluated the effects of premedication with intravenous clonidine on thiopental or propofol requirements for induction and haemodynamic changes associated with both induction and endotracheal intubation. Clonidine administered intravenously before induction of anaesthesia reduced propofol or thiopental requirements. The association of clonidine and propofol caused, after injection of the induction drug, a decrease in mean arterial pressure which was significantly greater than with thiopental. Moreover, a major haemodynamic stability was registered before and after laryngoscopy in the clonidine‐thiopental group. These findings might contraindicate the clonidine‐propofol combination in patients with cardiovascular disease.
Cost comparison between three different general anaesthetic techniques for elective arthroscopy of the knee
Authors: Heidvall M. , Hein A. , Davidson S. , Jakobsson J.
Published: March 2003

Introduction:

We compared three anaesthetic techniques for elective knee arthroscopy with special reference to cost‐effectiveness.

Method:

Seventy‐five ASA I–II patients having elective arthroscopy of the knee joint were randomised to receive an anaesthetic technique based on propofol, fentanyl for induction followed by sevoflurane in oxygen:nitrous oxide (1:2 l/min) for maintenance of one of two intravenous techniques: propofol alfentanil or propofol‐remifentanil infusions in combination with oxygen in air.

Results: All patients had an uncomplicated course. No differences were seen with regard to emergence, postoperative pain or emesis or time to discharge. The anaesthetic technique based on sevoflurane was associated with the lowest cost US$ 14.7 as compared to US$ 18 for the propfol/alfentanil and US$ 19.9 for the propofol/remifentanil technique, including both cost for wastage as well as premedication and other fixed drug costs. Looking only at the anaesthetic drugs consumed, the cost per minute was US$ 0.56 for sevoflurane/nitrous oxide as compared to US$ 0.68 and 0.63 per minute for the propofol/alfentanil and proprofol/remifentanil, respectively. When the cost for wastage was taken into account, the difference in mean anaesthetic drug cost was more pronounced: the sevoflurane anaesthetic technique US$ 0.58, the propofol/alfentanil US$ 0.74 and the propofol/remifentanil US$ 0.84 per minute respectively.

Conclusion: From a cost‐minimisation point of view, anaesthesia based on sevoflurane in oxygen:nitrous oxide is the technique of choice.
Nerve stimulation at 0.15 Hz when compared to 0.1 Hz speeds the onset of action of cisatracurium and rocuronium
Authors: Eikermann M. , Peters J.
Published: March 2003

Background: Onset time of specific non‐depolarizing muscle relaxants (NDMR), as reported in the literature, varies widely. To test the suggestion of a consensus panel (Copenhagen Consensus Conference 1996) that onset time in muscle relaxant studies depends on stimulation frequency, even in the low frequency range, we examined the onset time of cisatracurium and rocuronium by parallel ulnar nerve stimulation in both upper extremities at 0.1 Hz and 0.15 Hz.

Methods: Thirty patients (ASA class I and II) were included. Onset of action following the administration of 2×ED90 of cisatracurium (0.092 mg · kg−1) or rocuronium (0.74 mg · kg−1) was measured by quantifying the evoked response of the adductor pollicis muscles using mechanomyography. Single twitch stimulations were applied simultaneously to the ulnar nerves of both forearms using a 0.1 Hz and 0.15 Hz stimulation frequency, respectively.

Results: Both relaxants showed a significantly (P<0.01) shorter onset time with 0.15 Hz compared to 0.1 Hz stimulation (cisatracurium: 186±50 s vs. 233±59 s, rocuronium: 73±14 s vs. 99±23 s; x?±SD).

Conclusions: Onset time of NDMR depends on the stimulation frequency, even in the low frequency range. When comparing onset studies, the reader must also compare the stimulation rates used by the investigators. We recommend the use of 0.1 Hz single twitch nerve stimulation frequency as the standard for studies of onset profile of NDMR.
Coronary and systemic hemodynamic effects of clevidipine, an ultra‐short‐acting calcium antagonist, for treatment of hypertension after coronary artery surgery
Authors: Kieler‐Jensen N. , Jolin‐Mellgård Å. , Nordlander M. , Ricksten S.‐E.
Published: March 2003

Background: The aim was to evaluate the use of clevidipine, a new vascular selective, ultra‐short‐acting calcium antagonist for blood pressure control after coronary artery bypass grafting (CABG).

Methods: The effects of clevidipine on central hemodynamics, myocardial blood flow and metabolism were studied at two different phases after CABG. In phase 1 (n=13), the hypertensive phase, the effects of clevidipine were compared to those of sodium nitroprusside (SNP) when used to control postoperative hypertension. In phase 2 (n=9), the normotensive phase, a clevidipine dose‐response relationship was established.

Results: At a target mean arterial pressure (MAP) of 75 mmHg, systemic vascular resistance (SVR) and heart rate (HR) were lower, preload, stroke volume (SV) and pulmonary vascular resistance (PVR) were higher, while there were no differences in myocardial lactate metabolism or oxygen extraction with clevidipine compared to SNP. In the normotensive phase, clevidipine induced a dose‐dependent decrease in MAP (−19%), SVR (−27%) and PVR (−15%), accompanied by an increase in SV (10%), but no reflex increase in HR or changes in cardiac preload. Clevidipine caused a direct coronary vasodilation, as indicated by a decrease in myocardial oxygen extraction from 54% to 45%. Myocardial lactate metabolism was unaffected by clevidipine. The blood clearance of clevidipine was 0.05 l  ·  min−1  ·  kg−1, the volume of distribution at steady state was 0.08 l  ·  kg−1 and the initial and terminal half‐lives were <1 min and 4 min, respectively.

Conclusions: Clevidipine rapidly reduced MAP and induced a systemic, pulmonary and coronary vasodilation with no effect on venous capacitance vessels or HR. Clevidipine caused no adverse effects on myocardial lactate metabolism. Clevidipine thus appears suitable to control blood pressure after CABG.
Estimation of cardiac preload changes by systolic pressure variation in pigs undergoing pneumoperitoneum
Authors: Tournadre J. P. , Allaouchiche B. , Cayrel V. , Mathon L. , Chassard D.
Published: March 2003

Background: Variations in systolic pressure arterial waveform (SPV) and its component have been shown to be a reasonable indicator of left ventricular preload. Creation of a pneumoperitoneum (PMOP) by insufflation of CO2 increases intrathoracic pressure, leading to overestimation of preload as assessed by pressure methods. The purpose of this study was to compare SPV with other standard methods in anaesthetized pigs.

Methods: We measured SPV and its DeltaDown component (ΔDown), pulmonary artery occlusion pressure (PAOP) and left ventricular short‐axis cross‐sectional area using transthoracic echocardiography (TTE) in 7 pigs, at baseline, after 12 mmHg PMOP and after an intravascular load with 10 ml/kg hydroxylethylstarch (HES).

Results: PMOP increased SPV from 12.9±4.9 to 16.9±5.5 mmHg (P<0.05) and decreased pulmonary compliance, with no change in PAOP or end‐diastolic area assesssed by TTE. Intravascular volume loading significantly decreased SPV from 16.9±5.5 to 11.2±4.9 mmHg and ΔDown from 9.9±7.1 to 5.2±4.5 (P<0.05), and increased PAOP and end‐diastolic area. Significant correlation between changes in ΔDown and EDA was noted following HES (r=0.78, P<0.05).

Conclusion: In anaesthetized pigs, the creation of a PMOP alters SPV, likely by decreasing lung compliance. Once PMOP is established, changes in cardiac preload could be estimated by SPV analysis.
Supraceliac aortic cross‐clamping and declamping. Effects of dopexamine and dopamine on systemic and mesenteric hemodynamics, metabolism and intestinal tonometry in a rat model
Authors: Studer W. , Wu X.
Published: March 2003

Background: The effects of dopexamine and dopamine on mesenteric ischemia during reperfusion following aortic cross‐clamping are not known. We determined intramucosal tonometric PCO2 and PCO2 gap using a rat model of supraceliac aortic cross‐clamping and declamping.

Methods: Under pentobarbital and fentanyl anesthesia, 24 rats were surgically instrumented with arterial, right atrial, and portal venous catheters, ultrasonic flowprobes for measurements of abdominal aortic, superior mesenteric and carotid artery blood flow, and a pediatric tonometer for intestinal mucosal PCO2 measurements. Rats were randomized to receive a continuous infusion of dopexamine (10  · μg · kg−1 · min−1, n=8), dopamine (10 μg · kg−1 · min−1, n=8 ), or physiologic saline (control, n=8), infused at a rate of 4 ml · kg−1 · h−1, administered throughout the experimental protocol. After 30 min of drug infusion, the aorta was cross‐clamped at the supraceliac level for 30 min. Reperfusion following declamping was observed for 180 min.

Results: Intestinal tonometric PCO2 remained unchanged during drug treatment before aortic cross‐clamping, increased similarly in all groups following declamping during early reperfusion, and recovered to baseline within 30 min of reperfusion. Dopexamine treatment was associated with higher lactate levels and increased heart rate (P<0.05) during aortic cross‐clamping.

Conclusions: 1) Mesenteric ischemia, determined by intestinal tonometric PCO2 and PCO2 gap, recovers within 30 min of reperfusion following 30 min of aortic cross‐clamping irrespective of drug treatment and, 2) dopexamine induced higher lactate levels and increased heart rate during aortic cross‐clamping and should be carefully analyzed for potentially adverse effects on cardiac function.
A comparison of coracoid and axillary approaches to the brachial plexus
Authors: Koscielniak‐Nielsen Z. J. , Rotbøll Nielsen P. , Risby Mortensen C.
Published: March 2003

Background: Brachial plexus block by the coracoid approach does not require arm abduction and may be more effective than the axillary approach because of a more proximal injection of local anaesthetic. However, the clinical usefulness of the coracoid approach has not been tested in prospective controlled trials. The present randomized, observer‐blinded study compared success rates, time to obtain a complete block, frequency of adverse effects and block discomfort in two groups of 30 patients, anaesthetized for hand surgery using either the coracoid or the axillary approach to the brachial plexus.

Methods: After subcutaneous infiltration with 5 ml of 1% mepivacaine/adrenaline the brachial plexus was located using a nerve stimulator and an insulated pencil‐point needle. Ropivacaine 0.75%, 20–40 ml, depending on body weight, was used for the initial block. In the coracoid (C) group two plexus cords, and in the axillary (A) group four terminal nerves were electrolocated and the volume of ropivacaine was divided equally between them. Spread of analgesia to the arm was assessed every 5 min, by an anaesthetist unaware of the block technique. The block was defined as effective (complete) when analgesia was present in all five sensory nerve areas distal to the elbow. Incomplete blocks were supplemented 30 min after the initial block.

Results: In the C group a median 11 min was required for block performance as compared to 12 min in the A group (NS). Onset of block was shorter and the frequency of incomplete blocks lower in the A group (median 17 min and 17%) than in the C group (30 min and 47%, respectively). Lack of analgesia of the ulnar nerve was the main cause of incomplete initial blocks in the C group. All incomplete blocks were successfully supplemented. However, total time to obtain complete block was shorter in the A group than in the C group (29 min vs. 41 min, P<0.05). Accidental arterial puncture occurred in seven patients (five in C and two in A group), which resulted in two haematomas, both in the C group (NS). No permanent sequelae were observed.

Conclusion: The axillary approach to the brachial plexus using four injections of ropivacaine results in a faster onset of block and a better spread of analgesia than the coracoid approach using two injections.
Diclofenac or acetaminophen for analgesia in paediatric tonsillectomy outpatients
Authors: Rømsing J. , Østergaard D. , Drozdziewicz D. , Schultz P. , Ravn G.
Published: March 2003

Background:In order to establish an effective drug regimen, we compared the analgesic efficacy of oral diclofenac and high‐dose acetaminophen on pain after tonsillectomy.

Methods:In this randomised, double‐blind study 48 children, 5 to 15 years of age, following tonsillectomy were assigned to receive either diclofenac 2–3 mg kg−124 h−1(n=24) or acetaminophen 90 mg kg−124 h−1(n=24) for the first three days after surgery. Postoperative pain was assessed by self‐report each day before scheduled medication at 7 h, 12 h, 18 h and 23 h.

Results:The number of children rating severe pain was high in both the diclofenac group, 5–50%, and in the acetaminophen group, 12–58%, during the three day study period. Pain scores in the diclofenac group were only significantly lower at 12 h on day 1–3 compared to pain scores in the acetaminophen group (P<0.05). None of the children in the diclofenac group experienced any episodes of nausea/vomiting compared to 9 children in the acetaminophen group on day 1. The incidences of nausea/vomiting increased with pain (P<0.05). None of the 48 children experienced any episodes of bleeding.

Conclusions:This study indicates that diclofenac was no more effective than high‐dose acetaminophen (90 mg vs. 60 mg kg−124 h−1) for analgesia, but resulted in a lower incidence of nausea and vomiting in patients following tonsillectomy.
Postoperative pain control by epidural analgesia after transabdominal surgery
Authors: Andersen G. , Rasmussen H. , Rosenstock C. , Blemmer T. , Engbæk J. , Christensen M. , Ørding H.
Published: March 2003

Background: The efficacy of postoperative epidural pain treatment has been well documented in controlled studies. However, the literature concerning results of daily routine use of this method often only emphasises certain aspects of it.

Methods: A prospective study of 168 patients scheduled for major surgery with transabdominal access was performed in order to evaluate efficacy, side effects, complications and rate of acceptance of postoperative epidural pain treatment. The epidural catheter was placed before surgery and the patients received epidural analgesia by a bupivacaine/morphine mixture for 3 days postoperatively, continued by another 3 days with bolus injections of morphine only.

Results: Only few complications followed the insertion of the epidural catheter, but in about 16% of the patients the epidural catheter or the drugs administered by it made reinsertion or change in the type of analgesia necessary during the first 3 postoperative days. Despite the possibility for individualising the treatment and p.r.n. analgesics, pain relief when coughing and moving during day 1–3 was insufficient in 30–50% of the patients. Serious side effects were rare, but pruritus was frequent, as were the symptoms of nausea and vomiting. The patients were generally satisfied with the treatment; however, a small group had unacceptable pain when the epidural catheter was inserted.

Conclusion: Analgesia was insufficient when coughing and moving in an unacceptably large number of the patients. Also the number of epidural catheter related problems was high. In order to make early intervention possible, the patients and epidural catheters should be observed daily and systematically by members of the staff competent to detect possible problems.
Comparison between pentazocine, pethidine and placebo in the treatment of post‐anesthetic shivering Note
Authors: Terasako K. , Yamamoto M.
Published: March 2003

Background: We have compared the effects of pethidine, pentazocine and placebo in the treatment of post‐anesthetic shivering.

Methods: Forty‐five patients who shivered after routine surgery were allocated randomly to receive normal saline (n=15), pentazocine 7.5 mg (n=15) or pethidine 17.5 mg (n=15).

Results: After 10 min, 13 patients had stopped shivering in the pethidine group, which was significantly more than the incidence in the two other groups (placebo=2; pentazocine=4) (P<0.01). Pentazocine was not significantly different from normal saline in affecting shivering.

Conclusion: We conclude that pentazocine 7.5 mg was not effective in the treatment of post‐anesthetic shivering(
Note).
Midlatency median nerve evoked responses during recovery from propofol/sufentanil total intravenous anaesthesia Note
Authors: Rundshagen I. , Schnabel K. , Schulte Am Esch J.
Published: March 2003

Background: Median nerve somatosensory evoked responses (MnSSER) are frequently used to monitor the integrity of the somatosensory pathway during surgery. We investigated MnSSER components during the wakeup phase from anaesthesia with propofol/sufentanil, because detailed information is lacking about the reversibility of anaesthetic induced changes of MnSSER. The aim of the study was to document precisely the MnSSER waves in relation to the clinical awakening. The hypothesis was that anaesthetic induced MnSSER changes are reversed when the patient becomes responsive after anaesthesia.

Methods: In 20 gynaecological patients anaesthesia was maintained with propofol 8 mg kg−1 h−1 supplemented by bolus injections of sufentanil. MnSSER were recorded at C4′ (N20, P25, N35, P45, N50) following electrical median nerve stimulation on the day before surgery, after the end of surgery during anaesthesia and every 5 min during recovery, till the patients were responsive again and able to identify a shown object.

Results: While the primary cortical MnSSER complex N20P25 regained baseline values, the cortical latencies ≥35 ms remained prolonged (P<0.001) and the amplitudes P45N50 were suppressed (P≤0.013), when the patients were responsive after 26±7 min following anaesthesia. However, the amplitudes P25N35 exceeded their corresponding baseline value (P<0.01).

Conclusion: Persistent changes of MnSSER waves ≥35 ms reflect impaired signal processing along the somatosensory pathway following propofol/sufentanil anaesthesia when the patients are responsive again. Further studies combining MnSSER recording with distinct neuro‐psychological tests are needed to define the clinical relevance of these findings(
Note).
Halogenated volatile anesthetics inhibit carbon monoxide‐stimulated soluble guanylyl cyclase activity in rat brain
Authors: Masaki E.
Published: March 2003

Background: Because of halogen contents, halogenated volatile anesthetics (HVA) have a similarity to nitric oxide (NO) in terms of great affinity for the ferrous ion. Interactions between HVA and NO at the ferrous ion of soluble guanylyl cyclase (sGC) have been reported in different tissues. Carbon monoxide (CO), a more stable gas than NO, activates sGC by the same mechanism as NO. This study was undertaken to examine the effect of HVA on CO‐stimulated sGC activity in rat brain.

Methods: Sprague‐Dawley rat brain was homogenized and ultracentrifuged. The resulting supernatant was used as sGC fraction. The fraction was incubated with CO and HVA, and the activity of sGC was determined by measuring cyclic guanosine monophosphate (cGMP) production using an enzyme immunoassay in aliquots of the supernatant.

Results: CO clearly increased cGMP production in a dose‐dependent manner. Sevoflurane and isoflurane produced significant and dose‐dependent inhibition of CO‐stimulated sGC activity. There was no difference in the inhibitory effect between the two anesthetics. GTP dose‐dependently increased CO‐stimulated cGMP production. Both anesthetics decreased GTP production, but the inhibition by the anesthetics was not significant at higher GTP concentrations.

Conclusions: These results suggest that HVA can compete with CO at the ferrous ion of sGC and inhibit the activity of this enzyme.