bluuebunny/crossref_metadata_2025 huggingface dataset:
Premedication with sublingual buprenorphine for out‐patient arthroscopy: reduced need for postoperative pethidine but higher incidence of nausea
Authors: Juhlin‐Dannfelt M. , Adamsen S. , Olvon E. , Beskow A. , Brodin B.
Published: January 2009

The effect of preoperative sublingual buprenorphine (B) on postoperative pain (VAS), the need for postoperative opioid injections and on time to discharge, was evaluated in a prospective randomised double‐blind study. Forty ASA I‐II patients scheduled for arthroscopy of the knee received premedication with 0.4 mg buprenorphine (group B) and 42 patients were given placebo (group P). Postoperatively, pethidine was given to patients with pain. Three of the 40 patients in group B vs 11 of the 42 in group P received pethidine (P<0.05). In group B, however, 13 of the 40 patients complained of nausea, prolonging median time to discharge from 155 to 255 minutes (P<0.05). In group P, 3 of the 42 patients were nauseated, P<0.01, compared with group B. Time to discharge did not differ between the groups in patients without nausea. The median respiratory rate was significantly lower in group B, but no patient required ventilatory support. In conclusion, premedication with sublingual buprenorphine cannot be recommended for this procedure. It reduces the need for postoperative injections of pethidine but increases the incidence of postoperative nausea which prolongs the recovery time. Careful monitoring is also mandatory because of the possibility of respiratory depression.
Reliability of CO2 measurements from the airway by a pharyngeal catheter in unintubated, spontaneously breathing subjects
Authors: Waldau T. , ØBerg B. , Larsen V. H.
Published: January 2009

Although several short communications have appeared describing attempts to record the concentrations of carbon dioxide (CO2) from the unintubated airway by a catheter placed in the nose, so far only few reports have documented the reliability of the method. To evaluate the reliability of CO2 measurements by a catheter in the open, unintubated airway during spontaneous respiration, a 12 CH PVC catheter was forwarded through the nostril to the hypopharynx and connected to a capnograph in nine healthy volunteers. Another capnograph was connected to a tightly fitting face mask and simultaneous CO2 recordings were attained from the two parts of the airway during normoventilation, hyperventilation and rebreathing. A corresponding blood sample was drawn from the radial artery for blood gas analysis. The configurations of the capnograms recorded from the pharyngeal catheter were similar to those recorded from the face mask. The results were analysed by a multifactor analysis of variance. The carbon dioxide tension (pCO2) was significantly influenced by degree of ventilation (P<0.0001), subject (P<0.0001), measurement site (P=0.030) and interaction subject‐ventilation (P=0.015). In spite of the significant influence of the measurement site, the difference between end tidal carbon dioxide tension (PCO2(ET)) and carbon dioxide tension in arterial blood (PCO2(a)) was small. The mean differences between paired measurements (pCO2(ET)‐pCO2(a)) were ‐0.10 kPa±0.41 kPa (mean±SD) for the catheter and ‐0.20 kPa ±0.43 kPa for the face mask. The study demonstrates that reliable recordings of CO2 concentrations during spontaneous respiration can be obtained by a thin catheter positioned in the hypopharynx.
Peroperative and immediate postoperative adverse events in patients undergoing elective general and orthopaedic surgery: The Gothenburg study of perioperative risk (PROPER). Part II
Authors: Ouchterlony J. , Arvidsson S. , Sjöstedt L. , Svärdsudd K.
Published: January 2009

All anaesthetic and surgical procedures impose a certain risk of complications. However, reliable estimates of this risk from prospective studies are rare. This study is a prospective clinical epidemiological study of 1361 consecutive patients subjected to elective general and orthopaedic surgery.

These patients were followed from an extensive preoperative assessment to three months after the operation. In this report the peroperative and early postoperative period in the postoperative care unit or intensive care unit is described.

General anaesthesia was given to 59% and regional/local anaesthesia to 41%. Adverse peroperative events occurred in 19%. The most common were circulatory events (11%), respiratory (4%), and allergic events (1%). Most events were of minor severity. However, with the official registration system, only 1 out of 8 events was detected. In the postoperative unit one or more adverse event was noted in 47% of the cases. These were dominated by circulatory (18.4%) and respiratory events (5.0%). CNS depression was noted in 6.8% of the cases. Most per‐ and postoperative event variables were highly correlated to the degree of surgical stress. In conclusion, a new concept for preoperative assessment and the registration of events during and after surgery was used. In this way, a large number of events of importance, not least for quality assurance, were found that would be missed with the official coding system. In a previous report we could show that even minor events affected the cost of care substantially.
Nitrous oxide is a potent cerebrovasodilator in humans when added to isoflurane. A transcranial Doppler study
Authors: Strebel S. , Kaufmann M. , Anselmi L. , Schaefer H. G.
Published: January 2009

Nitrous oxide during neurosurgical procedures is almost always given in combination with either volatile or intravenous anesthetics. The modifying influence of such interventions has been studied clinically and in experimental settings; the reported findings, however, are inconsistent.

The present study compares the cerebrovascular effects of MAC equivalent concentrations of isoflurane alone and isoflurane plus nitrous oxide. Twenty lumbar laminectomy patients randomized either to receive isoflurane or isoflurane plus nitrous oxide were investigated over a dose range from 0.5 to 1.5 MAC. A transcranial Doppler (TCD) ultrasonography device was used to measure cerebral blood flow velocity (CBFV) in the right middle cerebral artery (MCA) as an index of anesthethic‐induced alterations in cerebral blood flow (CBF). A small but marginally significant decrease in CBFV at 1 MAC and no change at 1.5 MAC occurred in the isoflurane anesthetized patients. In contrast, a small but significant increase in CBFV at 1 MAC and a very significant increase at 1.5 MAC occurred in the isoflurane plus nitrous oxide anesthetized patients. Nitrous oxide added to an isoflurane anesthetic regimen is concluded to be a potent vasodilator. In addition, the vasodilating effects of nitrous oxide were not uniform; they progressively increased with an increasing isoflurane concentration.
Gastric tonometry: effect of sucralfate on calculated intramural pH
Authors: Motsch J. , Bach A. , Böhrer H. , Schmidt H. , Sghönau Th. , Martin E.
Published: January 2009

Tonometric measurement of gastric intramural pH (pHi) is a noninvasive method to assess adequacy of splanchnic perfusion. Calculation of pHi may be influenced by various factors. This prospective study was designed to determine if stress ulcer prophylaxis with sucralfate interferes with pHi measurement. Twenty‐five adult patients admitted to the intensive care unit (ICU) after open heart surgery were studied. Nasogastric tonometers were placed. Patients received sucralfate 1 g via the nasogastric tube 8 hours after termination of surgery, thereafter every 6 hrs. Gastric luminal pH and intramural pH were determined immediately prior and 1 hour after the first sucralfate administration. Gastric intramural pH was calculated from the arterial HCO3 concentration and the tonometrically determined intraluminal PCO2 value using the Henderson‐Hasselbaich equation. Intraluminal PCO2(SS) was measured to be 6.86±0.75 kPa prior to sucralfate administration as compared to 6.96±0.68 kPa 1 hour after 1 g sucralfate (P=0.92). Intramural pH, as calculated by tonometry, was 7.31±0.05 vs 7.31±0.05, and was thus not influenced by sucralfate administration (P=0.97). Mean gastric intraluminal juice pH was 4.2±1.3 compared to 4.2±1.2 (P=0.59). These data suggest that sucralfate does not interfere with tonometrically determined intraluminal PCO2 measurement and calculation of gastric intramural pH.
Fluid balance and pulmonary functions during and after coronary artery bypass surgery: Ringer's acetate compared with dextran, polygeline, or albumin
Authors: Tølløfsrud S. , Svennevig J. L. , Breivik H. , Kongsgaard U. , ØZer M. , Hysing E. , Mohr B. , Seem E. , Geiran O. , Abdelnour M. , Frøysaker T. , Noddeland H.
Published: January 2009

The effects on fluid balance, pulmonary tunctions and economics were evaluated in a randomized comparison of one colloid free and three colloid containing fluid regimens, for 48 hours during and after coronary artery‐bypass (CAB) surgery.

A standard regimen for anaesthesia, extracorporeal circulation and monitoring was used. Only Ringer's acetate (RAc) was used as priming solution for extracorporeal circulation. Forty patients were randomized to receive either RAc, polygeline 35 mg‐ml‐1 (Haemaccel®), dextran 70 (Macrodex®) 60 mg ml‐14, or albumin 40 mg‐ml‐1 in saline whenever fluid volume was needed to stabilize haemodynamics.

At the end of the operation, fluid retention was significantly lower in patients receiving polygeline and dextran 70, compared with patients receiving RAc. At 48 hours, however, there were no differences in cumulative fluid balance. Patients in the colloid groups postoperatively had a higher serum colloid osmotic pressure (s‐COP), bui a higher net lung capillary filtration pressure (AP) only on the second postoperative day than the RAc group. However, this did not adversely atfect intrapulmonary venous admixture, arterial oxygen tension, or time on respirator in the RAc group compared with the colloid groups. The most expensive colloid fluid regimen (albumin) cost about 230 USS more per patient than the RAc fluid regimen.

We conclude that Ringer's acetate for volume replacement to stabilize haemodynamics during and after CAB surgery is associated with increased fluid retention only during the intraoperative period, compared with dextran 70 or polygeline, and with a lower serum colloid osmotic pressure and net lung capillary filtration pressure postoperatively, compared with all three colloid groups. This does not affect pulmonary functions adversely. Thus, the RAc regimen is clinically fully acceptable and economically more favourable than the polygeline, dextran 70, and albumin‐containing fluid regimens.
Effects of heparin on the inhibitory action of protamine on endothelium‐mediated vasorelaxation
Authors: Akata T. , Kodama K. , Takahashi S.
Published: January 2009

The precise mechamism(s) of inhibitory action of protamine on endothelium‐mediated vasorelaxation has not been fully elucidated. In addition, no information is available regarding the effects of a heparin‐protamine complex on the endothelium‐mediated relaxation.

Employing isometric tension recording methods, we studied the effects of heparin, an anionic substance, on the protamine‐induced inhibition of acetylcholine (ACh)‐induced vasorelaxation in isolated rabbit small mesenteric artery.

Protamine (≥50 μg/ml) inhibited ACh (0.03–10 μM)‐induced relaxation under a norepinephrine (10 μM)‐stimu‐lated condition (P<0.05). The ACh relaxation, even 20 min after washout of protamine (150 μg/ml), was still significantly inhibited as compared to the control (before protamine) ACh relaxation, and further, it was not significantly different from the ACh relaxation maximally inhibited in the presence of protamine. Preapplication of heparin (700 U/ml) almost abolished the protamine inhibition (50 & 150 μg/ml) of the ACh relaxation. However, heparin (700 U/ml), applied on washout of protamine (150 ug/ml), had no effect on the prolonged protamine inhibition.

In conclusion, a heparin‐protamine complex had no direct effect on the endothelium‐mediated relaxation, and the inhibitory action of protamine on the endothelium‐mediated relaxation might be due to its polycationic property. The prolongation of protamine inhibition and the lack of effects of heparin on the prolonged protamine inhibition may suggest a toxic effect of protamine on the endothelium.
Adenosine increases the cutaneous heat pain threshold in healthy volunteers
Authors: Ekblom A. , Segerdahl M. , Sollevi A.
Published: January 2009

Adenosine is an endogenously produced substance which in animal experiments exerts anti‐nociceptive effects. In humans, algcsic effects have been presented following exogenous adenosine administration. A recent study on anaesthetized patients, however, suggested an anti‐nociceptive effect during i.v. adenosine. We have studied the pain‐reducing effect in healthy volunteers using adenosine 50–80 μg · kg‐1· min‐1(n = 10), morphine 0.1 mg · kg‐1(n = 5), adenosine 50 μg · kg‐1· min‐1+ morphine 0.1 mg · kg‐1(n=6), and ketamine 0.1 mg · kg‐1(n=5); all drugs given i.v., single‐blind. Quantitative sensory tests (QST) revealed a significantly increased cutaneous heat pain threshold following adenosine. No effect was seen following ketamine or morphine. Suprathreshold heat pain perception was unchanged in all subjects. Furthermore, warm and cold perception thresholds were not influenced significantly by any drug. Adenosine, morphine and kctamine produced well‐known side‐effects but of a mild intensity not necessitating any treatment.

The present results show that i.v. adenosine can provide a modest but selective increase of cutaneous heat pain thresholds, suggesting a pain‐reducing capacity of adenosine in humans.
Autotransfusion after open heart surgery: the oxygen delivery capacity of shed mediastinal blood is maintained
Authors: Schmidt H. , Kongsgaard U. , Kofstad J. , Geiran O. , Refsum H. E.
Published: January 2009

Autotransfusion of mediastinal shed blood after open heart surgery has become a common and accepted procedure in reducing the need for homologous transfusion during the last 15 years. The objectives of the present study were to investigate the oxygen delivery capacity of autotransfused shed mediastinal blood, compared to patient‐blood, during cardiopulmonary bypass and in the postoperative period.

Ten consecutive patients undergoing elective cardiac surgery were studied. Mediastinal shed blood was collected in the cardiotomy reservoir and retransfused during the first 18 postoperative hours. The oxygen delivery capacity of the blood to the tissues was calculated by use of the oxygen status algorithm (OSA 2.0) programme and measurement of the 2,3‐diphosphoglycerate (2,3‐DPG) concentration.

Autotransfusion volume ranged from 450–1530 ml per patient (median 824 ml). Shed blood had a mean haemoglobin level of 8.8 g/dl and 7.4 g/dl at 1 h and 6 h of autotransfusion, respectively. There were no significant changes of 2,3‐DPG concentration in the patient‐blood during cardiopulmonary bypass or after autotransfusion compared to preoperative values. P50 for oxygen (3.6 and 3.6 kPa) and 2,3‐DPG concentrations (5.3 and 5.1 mikromol/ml erythrocyte) in shed mediastinal blood (1h and 6h postoperatively) were not significantly different compared to patient‐blood.

The results demonstrate that the oxygen delivery capacity of shed mediastinal blood is maintained and that the oxygen affinity of patient‐blood is not influenced by autotransfusion.
Ketamine inhibits contractile responses of intestinal smooth muscle by decreasing the influx of calcium through the L‐type calcium channel
Authors: Hirota K. , Zsigmond E. K. , Matsuki A. , Rabito S. F.
Published: January 2009

During the inflammatory response, tissues release histamine (H), substance P, serotonin (5‐HT), prostaglandins and kinins, agents that mediate manifestations of inflammation such as pain, vasodilatation, increased capillary permeability and smooth muscle contraction. In this study we investigated whether racemic (R[+]) ketaminc (K) and its isomers are spasmolytic on intestinal smooth muscle contracted by inflammatory mediators, and whether the spasmolytic effect of K is related to changes in calcium influx through the L‐type calcium channel or to an interaction of K with opioid receptors.

We measured the contractions of guinea‐pig ileum mounted in an organ bath containing Tyrode's solution gassed with 95% O2/5% CO2 at 37d̀C. In the first protocol we determined the effect of K and its isomers on contractions induced by five mediators: 10 7 M H, 10‐8 M substance P, 10‐8 M ncurokinin A, 5X 10‐9 M bradykinin and 5X 10‐7 M 5‐HT. For each of these mediators, we plotted concentration‐response curves for the inhibitory effect of K, and from regression fitting of these curves, we calculated the IC50 (concentration of K that inhibited the contraction by 50%). In the second protocol we measured the contraction induced by the calcium ionophore A23187 (5.0X10‐6 M), both alone and after 1.8–7.2X 10‐4 M R(±)K. Then we examined how the inhibition caused by R(±)K was affected by increases in the concentration of extracellular calcium by adding calcium (1.8 7.2X10‐3 M). To study whether the L‐type calcium channel opener S(—)Bay K8644 or naloxone reverse the spasmolytic effect of K, we added 7.2X10‐1 M (R(±)K to the bath, followed by S(‐)Bay K8644 (2.5X 10‐8 2X 10‐7 M) or naloxonc (10 8‐3X 10‐6 Mi, and the response to H was elicited again.

R(±)K and its isomers inhibited the contraction of the ileum induced by all of the agents tested. No significant differences in the inhibitory potency were found among the three forms of K. Naloxone, on the contrary, did not affect the relaxant effect of K. The calcium ionophore A23187 produced ileum contractions that were effectively blocked by K. The calculated IC50 of K on histamine‐induced contractions was 4.7±0.7×10‐1 M with 1.8×10‐3 M calcium; this 1G50 increased significantly to 6.8±0.8×10‐4 M when calcium rose to 7.2×10‐3 M, P<0.01. The L‐type calcium channel opener S (—)Bay K8644, given after K, effectively restored the response of the muscle to H again in a dose‐dependent manner.

K and its isomers have equipotent inhibitory effect on ileum contraction induced by all the inflammatory mediators tested. This relaxant effect of K is related not to an interaction of K with opioid receptors but to changes in calcium influx through the L‐type calcium channel.
Paravascular lumbar plexus block: block extension after femoral nerve stimulation and injection of 20 vs. 40 ml mepivacaine 10 mg/ml
Authors: Seeberger M. D. , Urwyler A.
Published: January 2009

The goal of this prospective randomized study was to assess the extension of the “three‐in‐one” paravascular lumbar plexus block after femoral nerve stimulation and injection of 20 vs. 40 ml mepivacaine 10 mg/ml. Three‐in‐one blocks were achieved in 12 of 39 (31%) patients given 20 ml of 1% mepivacine (group 1), and 17 of 41 (41%) patients given 40 ml (Group 2) of the same solution (n.s). The level of successful blockade at each nerve did not differ between groups: The femoral nerve was blocked in 92% vs. 93% of patients in groups 1 and 2, respectively; the obturator nerve in 62% vs. 78%; and the lateral cutaneous femoral nerve in 41% vs. 44%. We conclude that femoral nerve stimulation is effective in faciliating blockade in the femoral nerve but not the obturator or lateral cutanous femoral nerve with the tested solution and volumes, and therefore not particularly effective for achieving complete 3‐in‐l blockade. Whithin the clinically relevant range of 20–40 ml, the volume of mepivacaine 10 mg/ml does not appear to influence the extent of blockade.
Differences in midazolam‐induced breathing patterns in healthy volunteers
Authors: Masuda A. , Haji A. , Wakasugi M. , Shibuya N. , Shakunaga K. , Ito Y.
Published: January 2009

Sex differences, and the influence of drug dosage and additional upper airway obstruction were studied in midazolam‐induced breathing patterns and sedation in 30 healthy volunteers (8 males and 22 females). After administration of 0.1 mg‐kg‐1 midazolam (8 male and 8 female subjects), the rib cage (RC) motion increased in 6 males and the abdominal wall (ABD) motion and SaO2 decreased in all males. In contrast, the RC and ABD motions and SaO2 decreased in all females. Snoring and loss of consciousness occurred in 7 males and in 2 females. There were significant differences in the RC motion, SaO2, the incidence of snoring and the sedative state between male and female subjects. A bolus dose of 0.5 mg of flumazenil completely antagonized the sedative effect of midazolam and restored the breathing pattern, whereas it did not completely restore SaO2. A higher dose (0.2 mg·kg‐1) of midazolam was administered to an additional 8 females. It caused a loss of consciousness in all subjects and increased the RC motion in only one subject. Partial obstruction of the nasal cavity was effected with cotton balls in the remaining 6 females who were sedated with 0.1 mg·kg‐1 midazolam. An increase in the RC motion occurred similar to that observed in males. These findings suggest a difference in midazolam‐induced sedation and breathing patterns between male and female subjects with midazolam administration on a mg · kg‐1 basis.
Perioperative monitoring of neuromuscular transmission using acceleromyography prevents residual neuromuscular block following pancuronium
Authors: Mortensen C. R. , Berg H. , El‐Mahdy A. , Viby‐Mogensen J.
Published: January 2009

The frequency of postoperative residual neuromuscular block following the use of the long‐acting non‐depolarizing muscle relaxants is high, and manual evaluation of the response to nerve stimulation does not eliminate the problem. In this prospective and randomized study we evaluated the hypothesis that perioperative use of acceleromyography would allow for a more rational and precise administration of the long‐acting muscle relaxant pancuronium resulting in a decrease in 1) the incidence and severity of postoperative residual neuromuscular block, 2) the amount of pancuronium used, and 3) the time from end of surgery to tracheal extubation. Forty adult patients were randomized into two groups, one managed without the use of a nerve stimulator, the other monitored using train‐of‐four (TOF) nerve stimulation and acceleromyography. All patients were anaesthetized with diazepam, fentanyl, thiopenione, nitrous oxide, and in some patients halothane, and they all received pancuronium 0.08–0.1 mg kg‐1 for tracheal intubation, and 1–2 mg for maintenance of neuromuscular block. Neostigmine 2.5 mg preceded by atropine 1 mg was administered for reversal. In the patients managed without a nerve stimulator, the trachea was extubated when the anaesthetist judged the neuromuscular function to have recovered adequately for upper airway protection and spontaneous ventilation. In patients monitored with acceleromyography, the trachea was extubaled when the TOF ratio was above 0.70. In all 40 patients, TOF ratio was measured using mechanomyography immediately after tracheal extubation and the patients were evaluated for clinical signs of residual neuromuscular block. Train‐of‐four ratios, as measured mechanically, varied between 0.26 and 0.96 (median 0.65) in the group not monitored dunng the operation with acceleromyography. Seven patients in this group were unable to sustain head lift for 5 seconds and five patients were unable to lift an arm to the opposite shoulder, as compared to 1 and 0 patients, respectively, in the group monitored using acceleromyography (P<0.05). The lime from end of surgery to tracheal extubation varied between 0 and 25 min (median 10 min) in the group not monitored as compared to 7–47 min (median 15 min) in the monitored group (P<0.01). There was no statistically significant difference in the total dose of pancuronium given in the two groups. It is concluded, that by using acceleromyography during Anaesthesia it is possible to avoid the problem of residual neuromuscular block following pancuronium. However, in this study this happened at the expense of a slightly prolonged recovery time (5 min longer). Under the conditions of the study the use of acceleromyography did not influence the amount of pancuronium used during anaesthesia.
Evaluation of anaesthesias in malignant hyperthermia negative patients
Authors: Islander G. , Ranklev‐Twetman E.
Published: January 2009

In vitro contracture test is still the most reliable method for diagnosing malignant hyperthermia susceptibility. In order to investigate the reliability of Malignant Hyperthermia Negative (MHN) results, a questionnaire was sent to 237 persons of whom 133 were consecutively investigated and found to be MHN, together with 104 of their children. In 17 anaesthetics with triggering agents in 7 MHN patients and 7 children of MHN patients, no signs of malignant hypcrthermia were observed in any patient. This material is, however, too small to draw any conclusion about the reliability of MHN test results. This can only be done in a large multicentre study or a metaanalysis of several studies.
The use of intravenous nitroglycerin for emergency cervicouterine relaxation
Authors: Wessen A. , Elowsson P. , Axemo P. , Lindberg B.
Published: January 2009

A patient with a twin pregnancy was in preterm labour after 25 gestational weeks when, during vaginal delivery of the second twin, severe spasm of the cervix and fetal bradycardia ensued. Induction of general anesthesia did not relax the cervix. After bolus doses of nitroglycerin 100 + 50 μg i.v., prompt cervicouterine relaxation was obtained allowing manual extraction of the baby. A short review of the literature and a summary of our experience in the administration of nitroglycerin i.v. in obstetrics are presented.
Neurological complications after anaesthesia. A follow‐up of 18 000 spinal and epidural anaesthetics performed over three years
Authors: Dahlgren N. , Törnebrandt K.
Published: January 2009

17 733 consecutive central blocks (8501 spinal and 9232 epidural anaesthetics) performed during a three‐year period were analyzed for alleged complications. Neurological complications related to anaesthesia were reported in 1 7 cases of which 13 patients had persisting lesions after three spinal and ten epidural blocks. In two patients given spinal anaesthesia, the technique was inadequate. In seven epidural blocks, the connection between neurological lesion and the anaesthetic technique could be argued. In five of these cases, polyneuropathy or nonspecific neurological symptoms were present. Three complications after epidural blocks were paraplegias caused by spinal haematomas in patients with deranged haemostatic capacity.
A double blind comparison of lidocaine 2% with or without glucose for spinal anesthesia
Authors: Harbers J. B. M. , Stienstra R. , Gielen M. J. M. , Cromheecke G. J.
Published: January 2009

The aim of the study was to compare lidocaine 2% plain to lidocaine 2% with glucose 8% for spinal anesthesia. Forty male patients scheduled for urologic surgery participated. The patients were randomly divided into two groups: the plain (P) group received 4 ml of glucose‐free lidocaine 2%, the heavy (H) group received 4 ml of lidocaine 2% containing 8% glucose. After the injection, the patients remained in the sitting position for three minutes before they were placed supine.

The onset and maximum level of sensory blockade were similar with both preparations (T7‐T8). In both groups there were respectively 3 (P) and 4 (H) patients who did not acquire a sensory level above T10. There was a tendency towards a longer duration of sensory blockade in the P group. The patients in both groups developed an almost complete motor blockade within approximately 10 minutes. Duration of complete motorblockade of the lower extremities was significantly shorter for the H group: 59.1 ±6.5 minutes (mean±SEM) than the P group: 89.5±6.4 minutes.

We consider lidocaine 2% with or without glucose a suitable agent for subarachnoid anesthesia for short procedures. As hyperbaric lidocaine results in a more rapid recovery of motor blockade, it may have advantages for patients in day‐case settings.
Comparison of spinal anaesthesia with epidural anaesthesia in paediatric surgery
Authors: Kokki H. , Hendolin H.
Published: January 2009

202 children aged 2 months to 17 years, undergoing elective paediatric operations below the umbilicus, were allocated randomly to receive either spinal (SA) or epidural anaesthesia (EA). SA was more efficacious since 8 children of 102 needed supplementation with general anaesthesia, in contrast to EA where 24 children of 100 were supplemented with general anaesthesia and 6 with fentanyl. The haemodynamic stability was maintained during EA, whereas during SA 6 patients were given medication to increase heart rate/blod pressure. EA provided longer pain relief than SA in the recovery room. The incidence of postoperative side effects was similarly low following SA and EA. Complaints after discharge were also similar. General weakness (7% vs 8% after SA and EA, respectively), low back pain (6% vs 6%), headache (7% vs 4%), fever (6% vs 4%) and positional headache (PDPH) (5% vs 3%) were the most frequent side effects. PDPH was only observed following SA in children aged 11 years or older. Following EA, PDPH was also observed in the younger age group after accidental clural puncture. In conclusion, we prefer SA for minor paediatric operations due to its high efficacy.
Phenylephrine in treating maternal hypotension due to spinal anaesthesia for caesarean delivery: effects on neonatal catecholamine concentrations, acid base status and Apgar scores
Authors: LaPortaDr. R. F. , Arthur G. R. , Datta S.
Published: January 2009

Maternal and neonatal catecholamine concentrations, following the use of either phenylephrine or ephedrine to treat a drop in maternal blood pressure after spinal anaesthesia for caesarean delivery, were compared. Patients were randomly assigned to one of two groups: Group 1 patients (n = 20) were treated with ephedrine given as 5 mg intravenous bolus injections; Group 2 patients (n = 20) were treated with phenylephrine given as 40 μg intravenous bolus injections, for decreases in maternal systolic blood pressure to maintain maternal systolic blood pressure above 100 mmHg. Maternal vein (MV), umbilical vein (UV), and umbilical artery (UA) blood samples were taken at the time of delivery. Samples were analyzed for catecholamine concentrations and blood gas values.

Noradrenaline concentrations in UA, UV and MV (at delivery) samples were significantly higher in group 1 compared to group 2; they were 6858±3689 vs 1674±944‐pg · ml‐1 (P<0.0001), 1265±758 vs 395±470 pg · ml‐1 (P<0.001) and 239±165 vs 103±93 pg · ml‐1 (P<0.01), respectively. Comparing blood gas values between groups 1 and 2, statistically significant differences were observed in UA pH (7.28±0.01 and 7.32±0.01 pH units, P=0.01), UA pCO2 (7.32±0.24 and 6.68±0.21 kPa, P=0.03), UA base excess (2.2±0.4 and 0.9±0.4 mmol · l‐1, P=0.04) and UV base excess (2.0±0.3 and 0.7±0.3 mmol · l‐1, P=0.004). No significant differences in maternal characteristics, acid base values, incidence of nausea and vomiting, and Apgar scores were observed between groups.

Phenylephrine appears to be as safe and effective as ephedrine in treatment of drop in blood pressure in healthy non‐labouring parturients undergoing caesearean delivery. The use of phenylephrine was also associated with significantly lower noradrenaline concentrations in both mother and neonate.
The duration of action of mivacurium is prolonged if preceded by atracurium or vecuronium
Authors: RautomaM.D. P. , Meretoja O. A. , Erkola O. , Kalli I.
Published: January 2009

We studied 45 patients (ASA I‐II) during propofol‐alfentanil‐N2O‐O2 anaesthesia to determine if recovery from neuromuscular block induced by mivacurium is influenced differently by prior injection of atracurium or vecuronium. Neuromuscular function was monitored by adductor pollicis EMG. Patients were randomized to receive two dosesof either mivacurium (150 and 70 μg kg‐1), atracurium (350 and 75 μg kg‐1) or vecuronium (70 and 15 μg kg‐1) followed by a final dose of mivacurium 70 μg kg‐1. The second and third doses of the muscle relaxants were administered at 25–30% recovery of the E1 (first EMG response in the train‐of‐four series). Following the final dose of mivacurium, the EMG response recovered to 25 and 95% in 10.4±3.9 and 19.7±5.7 min (mean±SD), respectively, if mivacurium was the only muscle relaxant. Respective times were 100% longer if mivacurium had been preceded by atracurium (23.8 ± 3.3 and 39.8±6.9 mm) or vecuronium (22.6±3.5 and 44.1 ±7.9 min) (P=0.000l). The 25–75% recovery times in the three groups were 4.9±1.0, 8.7±2.4 and 10.5±2.5 min, respectively (P=0.0001). Our results indicate that there is no benefit in giving mivacurium at the end of surgery after peroperative use of atracurium or vecuronium.
Hypoxic and hypercapnic ventilatory responses during isoflurane sedation and anaesthesia in women
Authors: Sollevi A. , Lindahl S. G. E.
Published: January 2009

This study primarily examined the effect of three endtidal isoflurane concentrations (0.2, 1.0 and 1.4%) on the isocapnic hypoxic ventilatory response (HVR), as well as the hypercapnic ventilatory response (HCVR), in 18 women (ASA I) who were all in the follicular phase of their menstrual cycle. Capnography was used, together with pulseoximetry to indicate desired levels of hypoxia (SpO2 75–80%). This hypoxic challenge resulted, after 3–4 min, in a stable ventilation, and ventilation measurements were then taken during a 90 s period. The HCVR provocation (inhalation of 4.5% CO2 in air) and measurements were conducted using a similar time frame as for HVR. Isoflurane 0.2% did not affect any ventilatory parameter. Isoflurane 1.0 and 1.4% dose‐dependently increased endtidal CO2 and respiratory rate, while tidal volumes decreased. Minute ventilation was not reduced. HVR, as well as HCVR, were both uninfluenced by isoflurane 0.2%. HVR was reduced by 60–70% at isoflurane 1.4% (P<0.0l), and was parallelled by a similar depression of HCVR (P<0.01). The HVR during anaesthesia was accomplished by a respiratory rate response, while the increase in tidal volume, seen in the awake state, was abolished. The HCVR during anaesthesia was, on the other hand, the result of a dose‐dependently depressed tidal volume response, without any increase in respiratory rate. In conclusion, isoflurane 0.2% did not affect the ventilatory response to mild isocapnic hypoxia, nor to mild hypercapnic challenge. During anaesthesia with isoflurane (1.0 and 1.4%), there was a parallel reduction of HVR and HCVR.
Reperfusion after cardioplegic cardiac arrest ‐ effects on intracoronary leucocyte elastase release and oxygen free radical mediated lipid peroxidation
Authors: Mair P. , Mair J. , Bleier J. , Waldenberger F. , Antretter H. , Balogh D. , Puschendorf B.
Published: January 2009

In experimental animal models reperfusion of ischaemic myocardium causes sequestration of leucocytes within the coronary circulation. Leucocytes contribute to postischaemic myocardial injury by releasing proteolytic enzymes and by generating oxygen free radicals. The aim of this study was to investigate whether leucocytes also contribute to myocardial injury following ischaemia and reperfusion associated with cardioplegic cardiac arrest. Therefore, we studied the release of the proteolytic enzyme elastase and oxygen free radical initiated myocardial lipid peroxidation in coronary sinus blood during reperfusion after cardioplegic cardiac arrest. The elastase‐alpha‐1‐proteinase inhibitor complex and malondialdehyde (a byproduct of myocardial lipid peroxidation) were measured in arterial, central venous and coronary sinus blood samples in 19 patients undergoing elective coronary artery bypass grafting before aortic crossclamping and 1,5, 10 and 20 min after aortic declamping. Malondialdehyde concentrations did not increase significantly during the study period, whereas elastase concentrations showed a significant increase during cardiopulmonary bypass in arterial, central venous as well as coronary sinus blood. Neither elastase nor malondialhyde concentrations in coronary sinus blood differed significantly from arterial or central venous blood at any time point measured. Our data demonstrated increased elastase concentrations during cardiopulmonary bypass, but we did not find enhanced intracoronary elastase release or myocardial lipid peroxidation. Our data suggest that patients are sufficiently protected from leucocyte mediated ischaemia reperfusion injury during uncomplicated coronary artery bypass grafting with cardioplegic arrest.
Thoracic paravertebral analgesia
Authors: RICHARDSON J. , SABANATHAN S.
Published: January 2009

Thoracic paravertebral nerve blockade, although once widely practised, has now only a few centres which contribute to the literature. Data production has, however, continued and this review correlates this new information with existing knowledge. Its history, taxonomy, anatomy, indications, techniques, mechanisms of analgesia, efficacy, contraindications, toxicity, side effects and complications are reviewed. Thoracic paravertebral analgesia is advocated for surgical procedures of the thorax and abdomen, especially wherever the afferent input is predominantly unilateral eg. thoracotomy, cholecystectomy and nephrectomy. It is also of benefit in the prevention and management of chronic pain. It is a simple undertaking with impressive efficacy. Plasma local anaesthetic levels are acceptable and its side effect and complication rates are low. No mortality has been reported. For unilateral surgery of the chest or trunk, thoracic paravertebral analgesia should be considered as the afferent block of choice. For bilateral surgery, its efficacy may be limited by the doses of local anaesthetic which could safely be used and further study in this area in particular is required. This form of afferent blockade deserves greater consideration and investigation.
Resistance to atracurium in rats with experimental inflammation: role of protein binchng
Authors: GARCIA E. , CALVO R. , RODRIGUEZ‐SASIAIN J. M. , JIMLNEZ R. , TROCONIZ I. F. , SUAREZ E.
Published: January 2009

The influence of altered protein binding on the neuromuscular effect of atracurium has been studied in rats with experimental inflammation induced by subcutaneous injection of turpentine oil.

Doses of atracurium ranging from 0.45 to 1.5 mg·kg‐1 were administered to control (n = 30) and to experimental inflammation induced rats (n = 30). Neuromuscular transmission was monitored by recording the twitch tension of the tibialis‐anterior muscle elicited by stimulation of the sciatic nerve. Three effect parameters were recorded: (i) intensity of the effect, measured as percentage depression of baseline twitch tension, (ii) duration of drug action (min) and (iii) recovery time (min).

The dose‐intensity of the effect relationship was modelled using a sigmoid Emax model. The ED50 (effective dose eliciting 50% of the maximum effect) was significantly increased (P<0.01) in the inflammation group as compared to the control group (0.94 vs. 0.68 mg·kg‐1). This change was reflected in a shift of the dose‐response curve to the right in the pretrcated rats. For equipotent doses ED95 (defined as the effective dose eliciting 95% of maximum effect), no differences were found in recovery time and duration of action between the two groups of rats. Mucoproteins levels (index of α1‐acid glycoprotein (AAG)) and protein binding were significantly increased in rats with experimental inflammation as compared to control rats.

Based on these results, altered serum protein binding of atracurium appears to be responsible, at least in part, for the resistance to atracurium.
Heart rate variability and preoperative anxiety
Authors: SLEIGH J. W. , HENDERSON J. D.
Published: January 2009

Power spectral analysis of heart rate variability has been used to gain some understanding of the activity of the autonomic nervous system. In this study various indices of heart rate variability were related to the degree of preoperative anxiety experienced by 32 patients presenting for day case surgery. It was found that there was no correlation between anxiety and mean heart rate, or between anxiety and the spectral power in the mid frequency band (0.05‐0.15 Hz). However, there was an increase in the relative power of the higher frequency band (0.15‐0.5 Hz) with increasing anxiety levels (Spearman correlation r=0.4034). This suggests that preoperative anxiety may often be associated with a relative vagal predominance in the sympathovagal balance.
Dopexamine and dopamine in the prevention of low gastric mucosal pH following cardiopulmonary by‐pass
Authors: GARDEBACK M. , SETTERCREN G.
Published: January 2009

The effect of low‐dose dopexamine and dopamine on gastric intramucosal pH (pHi) during cardiac surgery and 16 hours postoperatively was studied in 35 adult patients (coronary artery bypass grafting and/or valve replacement). The patients were assigned randomly to treatment groups with either dopexamine 1 μg. kg‐1.min‐1(n=12), dopamine 2.5 μg. kg‐1.min‐1(n=11) or to a control group (n=12). The infusions were started after induction of anesthesia and were continued until 16 hours after CPB. pHiand arterial pH (pHa) did not differ between groups and remained unchanged during cardiopulmonary by‐pass and for the first four postoperative hours. Both the carbon dioxide tension of arterial blood (PaCO2) and of the saline in the tonometer (PtonCO2) changed in parallel with a decrease during CPB and an increase after CPB and surgery with maximal values 12 hours after termination of CPB. A significant correlation was noted between pHiand pHaand between arterial and tonometric PCO2. It is concluded that low dose dopexamine and dopamine have no influence on pHiduring and after cardiac surgery. The observed changes in pHiand PtonCO2were due to changes in pHaand in PaCO2and not a sign of gastric mucosal ischemia
The effect of edothelium on the response to propofol on bovine coronary artery rings
Authors: GACAR N. , GOK S. , KALYONCU N. I. , OZEN I. , Soykan N. , AKTURK G.
Published: January 2009

In this study, the effect of propofol on isolated bovine coronary artery tone was studied in artery rings precontracted with PGF2α. Propofol, in concentrations of 10‐6‐10‐5 M did not change vascular smooth muscle tone, but at high concentrations (10‐4‐10‐1 M) produced relaxation in rings with intact endothelium. In rings denuded of endothelium or treated with methylene blue, propofol produced relaxation at 10‐3‐10‐1 M concentrations, but there was a significant decrease in relaxation compared to endothelium intact rings. In the presence of a calcium agonist (Bay K 8644; 10‐5 M), propofol produced constriction in rings denuded of endothelium.

These results suggest that high concentrations of propofol may have vasorelaxant effect on bovine coronary artery and that these effects may be due to actions on the endothelium and mediated by calcium channels.
Differential effects of dobutamine, dopamine, and noradrenaline on splanchnic haemodynamics and oxygenation in the pig
Authors: PRIEBE H.J. , NOLDGE G. F. E. , ARMBRUSTER K. , GEIGER K.
Published: January 2009

Supranormal oxygen (O2) transport may benefit critically ill patients. Catecholamines are clinically employed for this purpose. However, their effects on splanchnic haemodynamics and oxygenation are not well defined. The effects of dobutamine (DOBU), dopamine (DOPA), and noradrenaline (NA) on splanchnic blood flows (electromagnetic flow probes), O2deliveries and uptakes (catheterisation of portal and hepatic veins) were studied in nine anaesthetised (ketamine/flunitrazepam), ventilated, paralysed, and laparotomised pigs. All three catecholamines (DOPA at 15 μg·kg‐1· min‐1, DOBU at 13 μg · kg‐1· min‐1, NA at 0.4 μg · kg‐1· min‐1) significantly (P<0.05) increased cardiac output and systemic O2delivery. Only DOPA increased small intestinal and total hepatic blood flows, and O2deliveries, and decreased O2extractions. The same parameters did not change during DOBU. During NA, total hepatic blood flow and O2delivery decreased, and hepatic O2extraction increased. During all three catecholamines, small intestinal and total hepatic O2uptakes did not change significantly. Whereas hepatic arterial blood flow decreased during both DOPA and NE, portal venous flow increased during DOPA. These data suggest that in the experimental model used splanchnic O2supply and O2reserve capacity appear improved by DOPA, unaffected by DOBU, and impaired by NA.
Vasodilator effects of desflurane and isoflurane in the feline small intestine
Authors: SUNDEMAN H. , BIBER B. , R/IARTNER J. , RANER C. , WLYSÖ O.
Published: January 2009

The influence of desflurane (DES) and isoflurane (ISO) on the intestinal vasculature was investigated in normoventilated cats (n=10) during basal chloralose anesthesia (control). We measured heart rate, mean arterial pressure (MAP) and intestinal blood flow (optical drop flowmetry). Intestinal vascular resistance (IVR) was derived. To avoid changes in local vascular tone related to alterations in transmural pressure gradients, intestinal arterial pressure was controlled and kept constant by a variable aortic clamp. Measurements were performed during control and during the administration of DES (3.5% and 7.0% end‐tidal) or ISO (0.8% and 1.6% end‐tidal). Each animal was exposed to both agents, prior to and after intestinal postganglionic denervation. In the innervated intestine, both DES and ISO dose‐dependently decreased IVR. At the high dose, DES (50±10% decrease in IVR) was a significantly more powerful vasodilator than ISO (37±12% decrease in IVR). In the denervated intestine, less pronounced vasodilations were produced by both DES and ISO, as compared to the innervated state, and there were, in this situation, no significant differences between agents concerning the magnitude of the vasodilation. As indicated by comparisons between the innervated versus the denervated state, both neurogenic and non‐neurogenic mechanisms contributed to the vasodilator responses. The vascular relaxation at the high dose was for ISO associated with a significantly more powerful non‐neurogenic vasodilation, and for DES associated with a significantly more powerful neurogenic vasodilation. This suggests that withdrawal of sympathetic neurogenic vasoconstrictor tone is more important for the vasodilation produced by DES than it is for ISO.