bluuebunny/crossref_metadata_2025 huggingface dataset:
No inhibition of gastro‐intestinal propulsion after propofol‐or propofol/ketamine‐N2O/O2 anaesthesia: A comparison of gastro‐caecal transit after isoflurane anaesthesia
Authors: Freye E. , Sundermann St. , Wilder‐Smith O. H. G.
Published: January 2009

Background: Gastrointestinal motility may be considerably reduced by anaesthesia and or surgery resulting in postoperative ileus. Inhibition of propulsive gut motility is especially marked after an opioid‐based technique. Little, however, is known of the gastrointestinal effects of the hypnotic propofol when given continuously over a longer period of time, which is the case in total intravenous anaesthesia (TIVA) and in intensive care sedation. We therefore set out to study the effects of a propofol‐based nitrous oxide/oxygen anaesthesia (group PO) on gastro‐caecal transit time. The results were compared with a propofol‐ketamine technique (group PK) and an isoflurane‐based anaesthesia (group I; each group n=20).

Methods: Gastro‐caecal transit was determined by measurement of endexpiratory hydrogen concentration (ppm). Following gastral installation of lactulose at the end of the operation, the disacchharide was degraded by bacteria in the caecum, resulting in the liberation of hydrogen which was expired. A 100% increase in endexpiratory hydrogen concentration compared to the preinduction period was considered the end‐point of gastrocaecal transit.

Results: There was no significant difference with regard to gastro‐caecal transit in the three groups of patients. In the propofol group mean gastro‐caecal transit was 119 (±50.6 SD) min, in the propofol‐ketamine group it was 147 (±57.4 SD) min, and in the isoflurane group transit time was 122 (±48.6 SD) min.

Conclusion: The data suggest that propofol, even when given as a continuous infusion, does not alter gastrointestinal tract motility more than a standard isoflurane anaesthesia. The data may be particularity relevant to patients who are likely to develop postoperative ileus. They also suggest that in an ICU setting propofol does not alter gut motility more than a sedation technique with the analgesic ketamine.
Anaesthesia for caesarean section — a German survey
Authors: Messerschmidt A. , Wulf H. , Stamer U. M.
Published: January 2009

Background: Anaesthetic practice for caesarean section has changed during the last decades. There is a world‐wide shift in obstetric anaesthetic practice in favour of regional anaesthesia. Current data concerning anaesthetic practice in patients under‐going caesarean section from Germany are not available. A comparison with figures from the UK, USA, Norway and other European countries might be of general interest.

Methods: Questionnaires on the practice of anaesthesia for caesarean section and anaesthetic coverage of the obstetric units were sent to 1178 university, tertiary care, district, community and private hospitals in Germany.

Results: The 532 completed replies of this survey represent 46.9% of the German obstetric units. Most hospitals (42.3%) have delivery rates between 500 and 1000 per year. General anaesthesia is the most common anaesthetic technique for elective (61%), urgent (83%) and emergency caesarean section (98%). Epidural anaesthesia is performed in 23% of scheduled and 5% of non‐scheduled caesarean sections, and spinal anaesthesia in 14% and 10%, respectively. Acid aspiration prophylaxis before elective caesarean section is used in 68.7% of the departments. The majority of the departments provide a 24‐hour anaesthetic coverage; however, in only 6.2% of the units, this service is assigned to obstetric anaesthesia, exclusively.

Conclusion: Compared to data from 1978, anaesthetic practice for caesarean section has changed with an increase in regional anaesthesia. However, German anaesthetists prefer general anaesthesia for caesarean section. In contrast, anaesthetists in other countries predominantly use regional techniques, and the difference to German practice is striking. International consensus discussion and recommendations as well as comparable European instruments of quality control in obstetric anaesthesia are desirable.
Intrathecal administration of sameridine to patients subjected to arthroscopic knee joint surgery
Authors: Westman L. , Valentin A. , Eriksson E. , Ekblom A.
Published: January 2009

Background: Sameridine, a new substance with both local anesthetic and opioid effects, was administered intrathecally for the first time to humans, i. e. in patients subjected to arthroscopic knee joint surgery.

Method: A dose‐escalating (10, 15, 20 and 25 mg), open study was performed in 33 patients. Only two patients were included in the 25 mg group.

Results: Sameridine provided good quality of surgical anesthesia in all patients except those receiving 10 mg. The maximum level of sensory block, Th5–Th7, was reached within 30 min with a median duration of 3.6–3.9 h. The motor block was more profound with increasing dose, but never lasted longer than the sensory block. The influence on heart rate and blood pressure was minor and atropine and ephedrine were needed in four patients. No clinically significant ECG‐changes were detected and no arrhythmias were recorded. Oxygen saturation and respiratory rate did not decrease in a clinically significant way and were not affected by concomitant morphine given i. v. postoperatively. There were few side‐effects, the most frequent being mild pruritus (10/33).

Conclusion: Sameridine provided clinically adequate anesthesia for the patients receiving the doses of 15, 20 and 25 mg. Further studies are needed to evaluate the substance and it is of great interest to clinically investigate the opioid component with respect to postoperative analgesia.
Intraoperative autotransfusion is associated with modest reduction of allogeneic transfusion in prosthetic hip surgery
Authors: Lisander B. , Ivarsson I. , Jacobsson S. ‐A.
Published: January 2009

Background: The efficacy of intraoperative salvage and washing of wound blood and the predictors of allogeneic red cell transfusions in prosthetic hip surgery are insufficiently known.

Methods: In 96 patients, undergoing primary or revision surgery, salvaged and washed red cells and, if necessary, allogeneic blood were used to keep haematocrit not lower than 33%. The bleeding of red cells during hospital stay was calculated from the red cell balance. The preoperative red cell reserve (millilitres of red cells in excess of a haematocrit of 33%) was estimated and the difference between this volume and the total bleeding of red cells was retrospectively used to classify patients with regard to the need for red cells. Stepwise regression analysis was used to define patient‐related variables associated with allogeneic blood transfusion.

Results: Preoperative knowledge of the type of operation (primary, revision), the preoperative red cell reserve, and the body mass could predict roughly half of the need for banked blood (r2=0.45). Only one‐third of the total bleeding of red cells was retransfused. For complete avoidance of allogeneic blood, autotransfusion was most effective in patients with a moderate need (0–4 u). However, 32% of such patients required allogeneic blood.

Conclusions: Autotransfusion has a limited efficacy to decrease the need for allogeneic blood, and other blood‐saving methods should be added for this purpose. It is difficult to predict the need for allogeneic blood preoperatively.
Monitoring perioperative changes in distribution of pulmonary ventilation by functional electrical impedance tomography
Authors: Frerichs I. , Hahn G. , Golisch W. , Kurpitz M. , Burchardi H. , Hellige G.
Published: January 2009

Background: Electrical impedance tomography (EIT) is a noninvasive technique providing cross‐sectional images of the thorax. We have tested an extended evaluation procedure, the functional EIT (f‐EIT), to identify the local shifts of ventilation known to occur during the transition between spontaneous, controlled and assisted ventilation modes.

Methods: Ten patients scheduled for elective laparotomy were studied in the surgical ward, operating theatre and ICU during spontaneous and different modes of mechanical ventilation. Sixteen ECG electrodes were placed on the circumference of the thorax and connected with an EIT device (APT System Mark I, IBEES, Sheffield, UK). Measurements lasting 180 s were performed and f‐EIT images of regional ventilation computed. The geometrical centre of ventilation was determined to quantify the regional distribution of lung ventilation during individual modes of ventilation.

Results: F‐EIT confirmed the differences in the distribution of ventilation associated with various modes of artificial ventilation. Accentuated ventilation of the dependent lung regions was observed during spontaneous breathing, whereas a shift of the centre of ventilation to the nondependent regions was found during controlled ventilation. In the course of assisted ventilation a continuous displacement of the centre of ventilation back towards the dependent lung regions, consistent with an increased proportion of spontaneous breathing, was detected. Unassisted spontaneous breathing after weaning from mechanical ventilation resulted in a similar ventilation distribution as during tidal breathing prior to surgery.

Conclusion: F‐EIT determined the redistribution of lung ventilation during different modes of mechanical ventilation. We expect that f‐EIT will become a useful noninvasive bedside monitoring technique for imaging regional ventilation in pulmonary diseased patients during mechanical ventilation.
Epidural abscess after epidural analgesia treated successfully with antibiotics
Authors: Nordberg G. , Mark H.
Published: January 2009

Spinal extradural abscess is an infrequent but serious complication to extradural catheters. Early diagnosis is essential for successful treatment. An extradural abscess may develop slowly over days to several weeks and symptoms may be vague and unspecific, delaying correct diagnosis. Meticulous supervision of the patients is required and must continue as long as an epidural catheter is in place and for some time after the catheter has been withdrawn. This case report describes a patient undergoing extensive reconstructive plastic surgery after a leg trauma. For postoperative pain treatment a continuous epidural infusion of bupivacaine was given. After 10–14 days an extradural abscess developed with increasing low back pain but without any neurologic symptoms. With antibiotics a complete resolution of the extradural abscess occurred, documented by computerized tomography (CT).
Asymptomatic methaemoglobinaemia and its implications
Authors: Chawla R. , Kundra P. , Bhattacharya A.
Published: January 2009

Anaesthetists are well trained to detect subtle skin signs of life‐threatening situations such as cyanosis in hypoxia. However, cyanosis resulting from drug‐induced, asymptomatic methaemoglobinaemia is rare and is likely to go undetected preoperatively. Patients presenting with asymptomatic methaemoglobinaemia may, therefore, offer a dramatic challenge to the unprepared anaesthetist. We report a case of methaemoglobinaemia secondary to dapsone ingestion that was diagnosed intraoperatively.
The analgesic effect of racemic ketamine in patients with chronic ischemic pain due to lower extremity arteriosclerosis obliterans
Authors: Persson J. , Hasselström J. , Wiklund B. , Heller A. , Svensson J.‐O. , Gustafsson L. L.
Published: January 2009

Background: Ketamine in sub‐dissociative doses has been shown to have analgesic and phantom‐Limb pain, where conventional treatment has often failed. Chronic ischemic pain due to lower extremity arteriosclerosis obliterans often responds poorly to analgesics, and the pain‐generating mechanisms are not well understood.

Methods: Eight patients with rest pain in the lower extremity due to arteriosclerosis obliterans were given sub‐dissociative doses of 0.15, 0.30, or 0.45 mg/kg racemic ketamine and morphine 10 mg as a 5‐min infusion on four separate days in a cross‐over, double‐blind, randomised protocol. Plasma levels of (S)‐ and (R)‐ketamine and their nor‐metabolites were analysed with an enantioselective high‐performance liquid chromatography (HPLC) method. Pain levels were evaluated with a visual analogue scale (VAS).

Results: Individual pain levels were highly variable during and after all the infusions but the pooled pain levels showed a dose‐dependent analgesic effect of ketamine with a transient but complete pain relief in all patients at the highest dose (0.45 mg/ kg). Side‐effects, mainly disturbed cognition and perception, were pronounced and dose‐dependent. Morphine 10 mg had an analgesic peak at 20 min and 5/8 patients had complete pain relief. The remaining 3 patients also had high baseline pain scores, indicating a higher analgesic potency for the 0.30 and 0.45 mg/ kg ketamine doses than for morphine 10 mg.

Conclusion: We have demonstrated a potent dose‐dependent analgesic effect of racemic ketamine in clinical ischemic pain. Due to a narrow therapeutic window, this analgesic effect is probably best utilised in combination with other analgesics.
Postural post‐dural puncture headache after spinal and epidural anaesthesia. A randomised, double‐blind study
Authors: Flaatten H. , Felthaus J. , Larsen R. , Bernhardsen S. , Klausen H.
Published: January 2009

Background: This study was conducted in order to investigate the effect of patient expectation in the developement of postural post‐dural puncture headache (PPDPH).

Methods: 224 patients less than 55 years scheduled for minor non‐obstetric surgery were randomised to receive single‐injection spinal (SA) or epidural (EA) anaesthesia. A 27‐g Quinke needle was used for SA and a 18‐g Tuohy needle for EA. Patients, operating team and postoperative ward personnel were all blinded to the anaesthetic given and so was an independent observer responsible for follow‐up after 5–7 days. The occurrence of headache, backache and other complaints was recorded. Headache was classified as PPDPH or non‐PPDPH, and duration and intensity of the headache was registered. The quality of anaesthesia was directly evaluated by the surgeon using a VAS scale from 1(excellent) to 10 (very poor) and indirectly by the supplemental use of opioid analgesia and general anaesthesia in the two groups.

Results: 212 patients, 103 SA and 109 EA, with a mean age of 36.7 years, could be fully evaluated. The groups were comparable with regards to age, sex and surgical procedure performed. Headache occurred in 44 patients postoperatively. PPDPH was diagnosed in 16 patients (15.5%) in the SA group and 2 (1.8%) in the EA group (P=0.0014). Non‐PPDPH occurred in 13 patients in each group. PPDPH had significantly greater mean intensity and duration than non‐PPDPH. More patients in the EA group had postoperative backache (31.2%) than in the SA group (22.3%), but this difference was not statistically significant. More patients in the EA received general anaesthesia and opioid analgesia than in the SA group, and the surgeon's rating was on average 1.3 in the SA group compared to 2.5 in the EA group (P=0.0003).

Conclusions: SA gave more headache but superior quality of surgical anaesthesia compared with EA. Dural puncture, and not expectation, is the major cause of PPDPH.
Transient radicular irritation after spinal anesthesia induced with hyperbaric solutions of cerebrospinal fluid‐diluted lidocaine 50 mg/ml or mepivacaine 40 mg/ml or bupivacaine 5 mg/ml
Authors: Salmela L. , Aromaa U.
Published: January 2009

Background: Transient radicular irritation (TRI) is common after spinal anesthesia induced with hyperbaric lidocaine 50 mg/ml. The purpose of this study was to determine the incidence of TRI after spinal anesthesia with hyperbaric lidocaine 50 mg/ ml diluted with cerebrospinal fluid (CSF) 1:1 and hyperbaric mepivacaine 40 mg/ml and hyperbaric bupivacaine 5 mg/ml.

Methods: Ninety ASA class I‐IV patients undergoing mostly brief urological procedures under spinal anesthesia were randomly allocated to receive either hyperbaric lidocaine 50 mg/ ml diluted with CSF 1:1 (Group L), hyperbaric mepivacaine 40 mg/ml (Group M) or hyperbaric bupivacaine 5 mg/ml (Group B). Characteristics of the patients and details of the surgical procedures and spinal anesthesias were similar in all groups except for the intensity of motor block. The patients were evaluated on the first postoperative day by an anesthesiologist who did not know which spinal anesthetic agent had been used.

Results: Six patients (20%) in Group L, 11 patients (37%) in Group M and none (0%) in Group B experienced pain in the legs and /or back (TRI) after spinal anesthesia.

Conclusion: TRI is frequent after spinal anesthesia induced with hyperbaric lidocaine 50 mg/ml diluted with CSF 1:1. The incidence of TRI after hyperbaric mepivacaine 40 mg/ml is of the same magnitude. TRI could not be observed after bupivacaine spinal anesthesia.
Intrathoracic and pulmonary blood volume during CO2‐pneumoperitoneum in humans
Authors: Hachenberg T. , Ebel C. , Czorny M. , Thomas H. , Wendt M.
Published: January 2009

Background: Induction of CO2‐pneumoperitoneum may have significant effects on systemic and pulmonary haemodynamics. We hypothesized, that intrathoracic (ITBV) and pulmonary blood volume (PBV) are affected during intra‐abdominal CO2‐insufflation, which may be pronounced by positional changes of the patient.

Methods: Sixteen anaesthetized patients were studied before, during and after CO2‐pneumoperitoneum for laparoscopic cholecystectomy. A dye indicator technique was used to assess ITBV and PBV. In addition, gas exchange and haemodynamics were recorded.

Results: In the supine position, induction of CO2‐pneumoperitoneum had no effects on ITBV, PBV and cardiac output. Mean systemic arterial pressure increased from 10.9±1.5 kPa (82±11 mmHg) to 12.7±1.5 kPa (95±11 mmHg, P<0.01). In the reverse Trendelenburg position ITBV decreased from 19.8±5.1 ml . kg‐1 to 16.7±3.7 ml . kg1 (P<0.05) during CO2‐insufflation, but increased to control values after 20 min. PBV decreased from 4.2±1.2 ml . kg‐1 to 3.4±1.1 ml . kg‐1 (P<0.05) and remained decreased during CO2‐pneumoperitoneum. Calculated venous admixture was unchanged throughout the study. Deflation of CO2‐pneumoperitoneum increased ITBV (22.4±5.2 ml . kg‐1, P<0.05) and cardiac output above control values.

Conclusions: In anaesthetized‐paralyzed patients in the reverse Trendelenburg position intra‐abdominal CO2‐insufflation is associated with significant alterations of ITBV and PBV. The release of CO2‐pneumoperitoneum is associated with a re‐distribution of blood into the thorax.
No release of cardiac troponin I during major orthopedic surgery after acute normovolemic hemodilution
Authors: Hobisch‐Hagen P. , Schobersberger W. , Falkensammer J. , Luz G. , Innerhofer P. , Frischhut B. , Puschendorf B. , Mair J.
Published: January 2009

Background: Normovolemic hemodilution is a well‐accepted method for intraoperative blood salvage. However, some controversy exists concerning the possible risk of myocardial fiber injury as a consequence of the reduced oxygen content. Laboratory diagnosis of perioperative myocardial fiber injury is difficult, since biochemical markers are elevated postoperatively due to the surgical trauma. Cardiac troponin I (cTnI) is a new, highly sensitive and specific cardiac marker for the detection of myocardial injury. The aim of our study was to investigate whether normovolemic hemodilution in patients with major orthopedic surgery (13 hemodiluted patients, 15 controls) induces a release of cTnI.

Methods: cTnI as a highly specific and sensitive cardiac parameter, as well as total creatine kinase (CK), creatine kinase isoenzyme MB mass (CKMB mass) and myoglobin were measured after induction of anesthesia, after normovolemic hemodilution, prior to retransfusion of blood components, 3 h after surgery, and on the first and third postoperative days. Results: Prior to retransfusion of blood components the hematocrit was decreased to 25.4±1.2% (mean±SEM; range: 18%–34%) in the control group and to 20.2±0.8% (mean±SEM; range: 17%‐24%) in the hemodilution group. Total CK, CKMB mass as well as myoglobin concentration increased significantly in both groups, reaching their maxima within the first day of surgery. In contrast, cTnI was below the detection limit of the assay (<0.5 μg/L) at any time.

Conclusions: We suggest that pre‐ and intraoperative hemodilution to a hematocrit of approximately 20% by maintaining normovolemia does not induce myocardial fiber injury in patients without preexisting cardiac diseases.
Removal of activated complement from shed blood: comparison of high‐ and low‐dilutional haemofiltration
Authors: Arnestad J. P. , Hyllner M. , Bengtson J. P. , Tylman M. , Mollnes T. E. , Bengtsson A.
Published: January 2009

Background: Perioperative blood salvage is associated with release of inflammatory mediators. Depending on type of processing, the complement system is activated to some extent in the final blood product. The aim of the present study was to evaluate a haemofiltration technique concerning complement system activation and whether the volume of added saline will have an influence on the elimination of activated complement during processing.

Methods: Sixteen patients undergoing total hip arthroplasty received wound blood salvaged intraoperatively with a haemofiltration technique. Saline was added to the reservoir for washing in a ratio of 1:1 or 5:1 of estimated blood volume. Samples for determination of the anaphylatoxins C3a and C5a, and the terminal SC5b–9 complement complex (TCC) were drawn from the patients, the collected blood, the ultrafiltrate and the processed blood.

Results: Increased concentrations of C3a, C5a and TCC were found in aspirated and processed blood. Haemofiltration did not reduce the concentrations of these factors, except that of C3a in the group where saline was added in a ratio of 5:1. There were no increased concentrations of C3a, C5a or TCC in the patient plasma after reinfusion. No differences in blood pressure, heart rate, pH, arterial oxygen tension, arterial carbon dioxide tension, or base excess were found in association with rein‐fusion of the blood.

Conclusion: Collected shed blood washed through haemofiltration contained moderately elevated concentrations of C3a, C5a and TCC. Reinfusion of the blood neither led to increased systemic concentrations of complement activation products, nor to disturbances in haemodynamic or biochemical parameters.
Tissue perfusion in relation to cardiac output during continuous positive‐pressure ventilation and administration of propranolol or verapamil
Authors: Elowsson P. , Norlén K. , Jakobson S.
Published: January 2009

Background: Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive‐pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).

Methods: General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H2O end‐expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg−1followed by 0.15 mg · kg−1· h−1, n=8) or verapamil (0.1 mg · kg−1followed by 0.3 mg · kg−1· h−1, n=8).

Results: CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.

Conclusions: The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.
A bolus dose of 1.5 mg/kg amrinone effectively improves low cardiac output state following separation from cardiopulmonary bypass in cardiac surgical patients
Authors: Kikura M. , Levy J. H. , Bailey J. M. , Shanewise J. S. , Michelsen L. G. , Sadel S. M.
Published: January 2009

Background: The aim of this study was to evaluate the efficacy of 1.5 mg/kg bolus of amrinone on low cardiac output (CO) state following emergence from cardiopulmonary bypass (CPB) in cardiac surgical patients.

Methods: Immediately after emergence from CPB, 14 patients with a cardiac index (CI) less than 2.2 l min‐1 m‐2 despite administration of inotropes and nitroglycerin, received 1.5 mg/ kg amrinone over 3 min without changing catecholamine infusion rates (amrinone group). Hemodynamics and left ventricular short axis views with transesophageal echocardiography were recorded at baseline, 3, 5, and 10 min following amrinone administration. Left ventricular filling volumes were maintained constant by volume reinfusion from the CPB reservoir. We matched the data of the amrinone group with the other 14 patients who did not receive amrinone (non‐amrinone group) to evaluate the efficacy of amrinone in low CO state.

Results: At baseline, CI (1.8±0.1 1 min‐1 m‐2) in the amrinone group was significantly lower than CI (3.0±0.2) in the non‐amrinone group. Following amrinone administration, CI and velocity of circumferential fibershortening corrected for heart rate (Vcfc) significantly increased, and systemic vascular resistance index and pulmonary vascular resistance index significantly decreased from the baseline within 10 min without changes in heart rate, mean arterial blood pressure, or pulmonary artery occlusion pressure, and became equivalent with those of the non‐amrinone group.

Conclusions: A 1.5 mg/kg amrinone loading dose to patients in a low CO state, despite catecholamine therapy immediately after emergence from CPB, effectively improves ventricular function when loading conditions are maintained constant.
DA1‐receptor stimulation by fenoldopam in the treatment of postcardiac surgical hypertension
Authors: Gombotz H. , Plaza J. , Mahla E. , Berger J. , Metzler H.
Published: January 2009

Background: Besides adequate analgesia, sedation and ventilation, postcardiac surgical hypertension has to be treated frequently with vasoactive drugs to avoid possible complications. In this study the hemodynamic effects of the DA1‐receptor agonist fenoldopam (F) are compared to those of the Ca‐channel antagonist nifedipine (N).

Methods: Postoperatively, 64 CABG‐patients with a mean arterial pressure (MAP) of more than 105 mmHg over 10 min were investigated. Patients with compromised ventricular function, insufficient surgical repair, arrhythmia or an ECG unable to detect myocardial ischemia were excluded. The study drugs (initial dosage: F: 0.8; N: 0.3 μg kg‐1min‐1) were given continuously via a central venous catheter to reduce and to maintain the MAP between 80 and 95 mmHg. Hemodynamic parameters were determined using thermodilution technique.

Results:A significant reduction of the MAP (F: from 121 ±11 to 83±4, N: from 119±8 to 82±9 mmHg) and of the calculated systemic vascular resistance (SVR) (F: 2110±500 to 970±200, N: 1980±660 to 1020±300 dyn‐s‐cm‐5) were noted in both groups, whereby in the F group the therapeutic goal could be achieved more quickly with the dosage regimen chosen. As a result, a marked increase of heart rate, cardiac index and stroke volume index could be observed, which was more pronounced due to the initially stronger decrease of SVR with F. There was also a stronger decrease of pulmonary vascular resistance in the F group, but the indices of right ventricular function did not differ between the groups.

Conclusion: Fenoldopam seems to be an efficient alternative to nifedipine, especially because of its more rapid onset of action.
Total intravenous anaesthesia with propofol and remifentanil in paediatric patients: a comparison with a desflurane‐nitrous oxide inhalation anaesthesia
Authors: Grundmann U. , Uth M. , Eichner A. , Wilhelm W. , Larsen R.
Published: January 2009

Background: Remifentanil is a new rapid‐acting and ultra‐short‐acting μ‐opioid receptor agonist with few reports from use in children. Therefore, we compared a propofol‐remifentanil‐anaesthesia (TIVA) with a desflurane‐N2O‐anaesthesia (DN) with particular regard to the recovery characteristics in children.

Methods: 50 children (4–11 yr) scheduled for ENT surgery were randomly assigned to receive TIVA (n=25) or DN (n=25). After standardised i.v. induction of anaesthesia in both groups with remifentanil, propofol and cisatracurium, TIVA was maintained with infusions of propofol and remifentanil. Ventilation was with oxygen in air. DN was maintained with desflurane in 50% N2O. The administration of volatile and intravenous anaesthetics was adjusted to maintain a surgical plane of anaesthesia. At the end of surgery all anaesthetics were terminated without tapering and early emergence and recovery were assessed. In addition, side effects were noted.

Results: Both anaesthesia methods resulted in stable haemodynamics but significantly higher heart rate with desflurane. Recovery did not differ between the groups except for delayed spontaneous respiration after TIVA. Spontaneous ventilation occurred after 11±3.7 min versus 7.2±2.8 min (mean±SD, TIVA versus DN), extubation after 11±3.7 min versus 9.4±2.9 min, eye opening after 11 ±3.9 min versus 14±7.6 min and Aldrete score ≥9 after 17±6.8 min versus 17±7.5 min. Postoperatively, there was a significant higher incidence of agitation in the DN‐group (80% vs. 44%) but a low incidence (<10%) of nausea and vomiting in both groups.

Conclusion: In children, TIVA with remifentanil and propofol is a well‐tolerated anaesthesia method, with a lower peroperative heart rate and less postoperative agitation compared with a des‐flurane‐N2O based anaesthesia.
An unusual toxic reaction to axillary block by mepivacaine with adrenaline
Authors: Koscielniak‐Nielsen Z. J.
Published: January 2009

An increase in blood pressure, accompanied by atrial fibrillation, agitation, incomprehensible shouts and loss of consciousness, was observed in an elderly, ASA classification group II, cardio‐vascularly medicated male, 12 min after performance of axillary block with mepivacaine 850 mg containing adrenaline 0.225 mg, for correction of Dupuytren's contracture. After intravenous administration of labetalol, metoprolol and midazolam the patient's condition improved, and 15 min later he woke up. The block was successful and surgery was conducted as scheduled despite persisting atrial fibrillation. Postoperatively, the patient refused DC cardioversion and was treated medically. Both the temporal relationship of events and the response to treatment suggest that a rapid systemic absorption of mepivacaine with adrenaline and/or interaction of these drugs with the patient's cardiovascular medications were responsible for the perioperative complications.
Costoclavicular pinching: a complication of long‐term central venous catheters: A report of three cases
Authors: Nøstdahl T. , Waagsbø N. A.
Published: January 2009

In the course of 1994–1995 we found three nearly identical cases involving fracture of polyurethane catheters from subcutaneous implantable vascular ports. This resulted in complications: leakage of drugs and infusions and thereby soft tissue damage. The leakage occurred in the costoclavicular space in all instances. We assume that the catheters have been subjected to repeated pinching, resulting in material fatigue. In order to eliminate the risk of this serious complication, the subclavian route should be avoided and preference given to the approach via the internal jugular vein.
Pharmacokinetics and clinical effect during continuous epidural infusion with ropivacaine 2.5 mg/ml or bupivacaine 2.5 mg/ml for labour pain relief
Authors: Irestedt L. , Ekblom A. , Olofsson C. , Dahlstrom A.‐C. , Emanuelsson B.‐M.
Published: January 2009

Background: Ropivacaine has shown less systemic toxicity than bupivacaine, and comparatively low muscle‐blocking properties could constitute another advantage when used epidurally for obstetric pain relief. We aimed primarily to compare maternal and foetal drug disposition following continuous epidural infusion of ropivacaine or bupivacaine.

Methods: Twenty‐four full‐term, nulliparous women were randomized to continuous epidural infusion (10 ml/h) of ropivacaine 2.5 mg/ml or bupivacaine 2.5 mg/ml for labour pain relief in a double‐blind, parallel‐group design. Maternal blood samples were collected up to 24 h after the end of infusion as well as taken from the umbilical cord at the time of delivery. Sensory and motor block as well as analgesia were assessed. All the women were monitored by cardiotocography and neonatal assessment was performed.

Results: The sensory block was adequate for both drugs. Higher plasma levels (total and free) were seen with ropivacaine, although the infusion with bupivacaine continued on average for about 2 hours longer. However, the ratios between maternal and umbilical blood concentrations were similar for both drugs. Normal neonatal Apgar and neonatal adaptive capacity scores (NACS) were found in both groups.

Conclusion: A continuous epidural infusion of 25 mg/h ropivacaine or bupivacaine both produced good labour pain relief. Higher total and free plasma concentrations were seen for ropivacaine. The ratios between maternal and umbilical plasma levels were similar for both drugs.
Epidural fentanyl, adrenaline and clonidine as adjuvants to local anaesthetics for surgical analgesia: meta‐analyses of analgesia and side‐effects
Authors: Curatolo M. , Petersen‐Felix S. , Scaramozzino P. , Zbinden A. M.
Published: January 2009

Background: The risk/benefit ratio of adding fentanyl, adrenaline and clonidine to epidural local anaesthetics for improving intraoperative analgesia is unclear. This meta‐analysis was performed to clarify this issue.

Methods: Trials retrieved by search were considered if they were prospective, controlled, epidural analgesia (without combining general anaesthesia) was planned and occurrence of pain during surgery or side‐effects were reported. Papers entered meta‐analysis if they reached a predefined minimum quality score. Pooled odds ratios (OR) and confidence intervals (CI) were computed. P<0.05 was considered as significant.

Results: Eighteen trials were included in the analysis for fentanyl. Fentanyl decreased the likelihood of pain (OR=0.21, 95% CI=0.15–0.30, P<0.001) and increased the incidence of pruritus (OR=5.59, 95% CI=3.12–10.05, P<0.001) and sedation (OR= 1.88, 95% CI=1.19–2.98, P=0.003), compared to control (local anaesthetic without fentanyl). Fentanyl had no effect on respiratory depression, nausea, vomiting and Apgar score. One case of respiratory depression of a newborn was observed. Because of the very low number of trials selected, evaluation of adrenaline and clonidine was not feasible.

Conclusion: The analysis of current literature shows that the addition of fentanyl to local anaesthetics for intraoperative epidural analgesia is safe and advantageous. The reduction in the incidence of pain during surgery is quantitatively high and therefore clinically significant. Side‐effects are mild. Randomized, controlled trials have to be performed in order to clarify the role of adrenaline and clonidine as epidural adjuvants for surgical analgesia.
The effect of i. v. enalaprilat in chronically treated hypertensive patients during cardiac surgery
Authors: Schuetz W. H. , Lindner K. H. , Georgieff M. , Mueller S. , Oertel F. , Radermacher P. , Gauss A.
Published: January 2009

Background:Angiotensin‐converting enzyme (ACE) inhibitors are well established as long‐term antihypertensives and have also been proved useful in hypertensive emergencies. Therefore, we investigated whether intraoperative i. v. enalaprilat may reduce the incidence of perioperative hypertensive reactions in coronary artery bypass grafting (CABG).

Methods:Thirty‐eight male patients chronically treated for arterial hypertension and scheduled for CABG randomly and double‐blindly received either enalaprilat 30 μg · kg−1or NaCl 0.9% at the time of skin incision. Intraoperatively increases of mean arterial pressure (MAP) >85 mmHg or >80 mmHg during cardiopulmonary bypass (CPB) were treated by an urapidil bolus. The total intraoperative amount of urapidil was documented for both groups. Systemic and pulmonary hemodynamics as well as the plasma levels of epinephrine, norepinephrine, arginine vasopressin and renin were measured intraoperatively and up to 2 h after admission to the intensive care unit.

Results:Mean arterial pressure, cardiac index and systemic vascular resistance did not differ between the enalaprilat and the control group. Renin plasma levels significantly increased after infusion of enalaprilat and did not change in the placebo group. Catecholamine and arginine vasopressin plasma levels increased significantly during CPB and remained high in the postoperative period without any intergroup difference. The same amount of urapidil had to be given in the two groups to maintain MAP below the defined limit.

Conclusion:We conclude that infusing 30 μg · kg−1enalaprilat in patients chronically treated for arterial hypertension does not prevent hypertensive reactions during CABG.
Vasopressor hormone response following mesenteric traction during major abdominal surgery
Authors: Brinkmann A. , Seeling W. , Wolf C. F. , Kneitinger E. , Schonberger C. , Vogt N. , Orend K. H. , Buchler M. , Radermacher P. , Georgieff M.
Published: January 2009

Background: We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI2) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia.

Methods: In a prospective, randomized, placebo‐controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4‐L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6‐keto‐PGFlα (stabile metabolite of PGI2), TXB2 (stabile metabolite of thromboxane A2) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high‐pressure liquid chromatography (HPLC) with electrochemical detection.

Results: Following MT, arterial hypotension occurred along with a substantial PGI2 release. This was completely abolished by ibuprofen administration. Although plasma levels of 6‐keto‐PGF1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB2 (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo‐treated patients.

Conclusion: Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI2 release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A2, presumably contributing to hemodynamic stability within 30 min after MT.
Haemodynamic and metabolic changes induced by repeated episodes of hypoxia in pigs
Authors: Licker M. , Schweizer A. , Hohn L. , Morel D. R.
Published: January 2009

Background: Repeated hypoxia and surgical trauma trigger a potent neuroendocrine response and their association is thought to play a pivotal role in the pathogenesis of multi‐organ dysfunction. We investigated the cardiovascular and metabolic responses to repeated acute hypoxia in anaesthetised and surgically instrumented pigs.

Methods: Under ketamine‐midazolam anaesthesia, 15 pigs were surgically instrumented for measurements of cardiac output, vascular pressures and organ blood flows. Lactate production and O2 uptake were determined in the brain, liver, kidney and intestine. Ten animals were subjected to two 12‐min periods of ventilatory hypoxia (FIO2=7%) followed by re‐oxygenation and 5 animals underwent 120–min normoxic ventilation (Control group).

Results: Both hypoxic challenges produced a comparable release of catecholamines that was associated with increased cardiac output and redistribution of blood flow away from the intestinal and renal areas towards the brain and the liver; O2 uptake was markedly reduced in the intestine (– 56 ± 10%, P < 0.05) and least affected in the brain and the kidney (– 19±12% and — 23±21%, respectively). During the second hypoxic test, lethal cardiovascular depression occurred in 5 animals; these non‐survivors demonstrated impaired hyperdynamic response and incomplete recovery of intestinal O2 uptake during the first hypoxia/reoxygenation test. In the Control group, normoxic ventilation was not associated with significant haemodynamic and metabolic changes.

Conclusion: Intraoperative hypoxia causes marked heterogeneity in organ blood flow and metabolism. The inability to develop a hyperdynamic cardiovascular response during a first hypoxic event, as well as a persistent intestinal O2 debt following re‐oxygenation, predict the occurrence of death during the second hypoxic insult.
Renal dysfunction after total knee replacement is not aggravated by bone cement
Authors: Nergelius G. , Lidgren L. , Grubb A. , Vinge E.
Published: January 2009

Background: Total knee replacement (TKR) has been associated with postoperative renal dysfunction. The use of monomeric methylmethacrylate (MMA) bone cement causes hypotension by several mechanisms.

Methods: In 30 patients undergoing TKR with (n=16), or without (n = 14) bone cement, serum levels of creatinine, cystatin C and creatine kinase (CK) and urinary levels of creatinine and markers for glomerular (albumin, IgG) and tubular (protein HC) function were recorded preoperatively and on days 1, 2, 4 and 8 postoperatively.

Results: There were no changes in serum creatinine. Both groups had a transient, 5‐fold rise in CK and a continuous increase in cystatin C. The urinary concentration of proteins increased postoperatively with a peak in the glomerular markers on day 1 and in the tubular marker on day 2. There were no significant differences in proteinuria between the groups. The 95% CIs for the difference in the means of the AUCs of the logarithmically transformed values for the proteins were never more than 19%. On day 8 all proteins had returned to their preoperative levels.

Conclusion: Postoperatively, there was a transient increased leakage of proteins, indicating glomerular and tubular dysfunction. This was not influenced by the use of MMA bone cement.
Effects of ketorolac and dextran‐70 alone and in combination on haemostasis
Authors: Power I. , Noble D. W. , Winter A. , Greer I. A.
Published: January 2009

Background: Dextran may be used in surgical patients for thromboprophylaxis or volume expansion along with ketorolac, a nonsteroidal anti‐inflammatory drug, for analgesia. As these two agents can influence the haemostatic system at different sites, it is important to demonstrate that there is no adverse haemostatic interaction between them.

Methods: The haemostatic interaction between intravenous dextran‐70 and intramuscular ketorolac was assessed in a double‐blind, randomised, crossover study of healthy male volunteers each given all four combinations of ketorolac/placebo intramuscularly and dextran/placebo intravenously. The effect of ketorolac and dextran on haemostasis was assessed by the following techniques: skin bleeding time, in vitro platelet aggregation function, whole blood thromboxane generation, von Willebrand factor antigen, factor VIII coagulant activity and tissue plasminogen activator. The results were analysed for the effects of ketorolac and dextran and for any evidence of an interaction.

Results: Ketorolac inhibited platelet function and thromboxane generation. Dextran reduced factor VIII coagulant activity. Neither agent had a significant effect on bleeding time, von Willebrand factor or tissue plasminogen activator. There was only evidence of a small but statistically significant interaction between ketorolac and dextran on thromboxane generation. There was no evidence of any other interaction of ketorolac with dextran. Conclusion: This interaction on thromboxane generation is unlikely to be of clinical significance as substantial inhibition of thromboxane generation occurs with ketorolac alone.
Volatile anaesthetics reduce adhesion of blood platelets under low‐flow conditions in the coronary system of isolated guinea pig hearts
Authors: Heindl B. , Becker B. F. , Zahler S. , Conzen P. F.
Published: January 2009

Background: Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.

Methods: Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low‐flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low‐flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in‐ and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.

Results: At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low‐flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P<0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.

Conclusion: Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.
Surgeon's experience as a factor for emetic sequelae after middle ear surgery
Authors: Honkavaara P. , Pyykkö I.
Published: January 2009

Purpose: To test the hypothesis that an experienced surgeon is associated with less postoperative nausea and vomiting (PONV).

Methods: A post hoc analysis was done on the data of 167 patients from 3 randomized studies on the prevention of PONV, with transdermal scopolamine, ondansetron and propofol, in middle ear surgery under general anaesthesia.

Results: The patients in the residents' group suffered more from PONV (69% vs. 42%, P<0.01) and from retching or vomiting (52% vs. 23%, P<0.001) than those in the specialists' group. The proportion of patients needing droperidol was also higher in the residents' group (66% vs. 27%, P<0.001). The durations of anaesthesia and surgery seemed to correlate positively with PONV. In matched‐pair analysis, residentship was confirmed as a risk factor for emetic symptoms. In the residents' group, prophylaxis of PONV resulted in a decrease in retching and vomiting from 71% to 29% (P<0.01), and in patients needing droperidol from 87% to 46% (P<0.01).

Conclusion: The patients operated by residents need more aggressive prophylaxis for PONV than those operated by specialists in middle ear surgery.