S C Kettner

IST Austria, Klosterneuberg, Lower Austria, Austria

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Publications (66)232.58 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: /st>The relation between the pattern of local anaesthetic (LA) spread and the quality of peripheral nerve block is unclear. /st>Twenty-one volunteers were randomized to receive a median nerve block with intended circumferential or intended non-circumferential spread of LA. Different predetermined volumes and needle placement techniques were used to produce the different patterns of LA spread. Volumetric, multiplanar 3D ultrasound imaging was performed to evaluate the pattern and extent of LA spread. Sensory block was assessed at predetermined intervals. /st>Complete circumferential spread of LA was achieved in only 67% of cases in the intended circumferential study group and in 33% of cases in the intended non-circumferential group. Block success was similar (90%) and independent of whether circumferential or non-circumferential spread of the LA was achieved. All block failures (n=4) occurred in the intended non-circumferential group with low volumes of LA. The onset of sensory block (independent of group allocation) was faster with circumferential spread of LA [median (IQR) onset time, 15 (8; 20) min] compared with non-circumferential spread of LA [median (IQR) onset time, 20 (15; 30) min]. More LA was used for circumferential blocks [median (IQR) volume of LA 2.8 (1.3; 3.6) vs 1.3 (1.1; 2.4) ml]. /st>Even under optimal conditions, it was not possible to achieve circumferential spread of LA in all intended cases. The success of median nerve block seems to be independent of the pattern of LA spread.Clinical trial registrationDRKS 00003826.
    BJA British Journal of Anaesthesia 02/2014; · 4.24 Impact Factor
  • S C Kettner
    BJA British Journal of Anaesthesia 07/2013; 111(1):123. · 4.24 Impact Factor
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    ABSTRACT: BACKGROUND:: This study was designed to examine the spread of local anesthetic (LA) via magnetic resonance imaging after a standardized ultrasound-guided thoracic paravertebral blockade. METHODS:: Ten volunteers were enrolled in the study. We performed ultrasound-guided single-shot paravertebral blocks with 20 ml mepivacaine 1% at the thoracic six level at both sides on two consecutive days. After each paravertebral blockade, a magnetic resonance imaging investigation was performed to investigate the three-dimensional spread of the LA. In addition, sensory spread of blockade was evaluated via pinprick testing. RESULTS:: The median (interquartile range) cranial and caudal distribution of the LA relative to the thoracic six puncture level was 1.0 (2.5) and 3.0 (0.75) [=4.0 vertebral levels] for the left and 0.5 (1.0) and 3.0 (0.75) [=3.5 vertebral levels] for the right side. Accordingly, the LA distributed more caudally than cranially. The median (interquartile range) number of sensory dermatomes which were affected by the thoracic paravertebral blockade was 9.8 (6.5) for the left and 10.7 (8.8) for the right side. The sensory distribution of thoracic paravertebral blockade was significantly larger compared with the spread of LA. CONCLUSIONS:: Although the spread of LA was reproducible, the anesthetic effect was unpredictable, even with a standardized ultrasound-guided technique in volunteers. While it can be assumed that approximately 4 vertebral levels are covered by 20 ml LA, the somatic distribution of the thoracic paravertebral blockade remains unpredictable. In a significant percentage, the LA distributes into the epidural space, prevertebral, or to the contralateral side.
    Anesthesiology 02/2013; · 5.16 Impact Factor
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    ABSTRACT: BACKGROUND: /st>Dexmedetomidine is an α-2-receptor agonist which might be used as an additive to local anaesthetics for various regional anaesthetic techniques. We therefore designed this prospective, double-blinded, controlled volunteer study to investigate the effects of dexmedetomidine as an adjuvant to ropivacaine on peripheral nerve block. METHODS: /st>Ultrasound-guided ulnar nerve block (UNB) was performed in 36 volunteers with either 3 ml ropivacaine 0.75% (R), 3 ml ropivacaine 0.75% plus 20 µg dexmedetomidine (RpD), or 3 ml ropivacaine 0.75% plus systemic 20 µg dexmedetomidine (RsD). UNB-related sensory and motor scores were evaluated. RESULTS: /st>Sensory onset time of UNB was not different between the study groups, whereas motor onset time was significantly faster in Group RpD when compared with the other study groups [mean (sd)] [21 (15) vs 43 (25) min in Group RsD and 47 (36) min in Group R, P<0.05 Group RpD vs other groups]. The duration of sensory block was 350 (54) min in Group R, 555 (118) min in Group RpD, and 395 (40) min in Group RsD (P<0.01 Group RpD vs other groups, P<0.05 Group RsD vs Group R). Motor block duration was similar to the duration of sensory block. CONCLUSIONS: /st>A profound prolongation of UNB of ∼60% was detected with perineural dexmedetomidine when added to 0.75% ropivacaine. The systemic administration of 20 µg dexmedetomidine resulted in a prolongation of ∼10% during UNB with 0.75% ropivacaine.Eudra-CT No.: 2012-000030-19.
    BJA British Journal of Anaesthesia 11/2012; · 4.24 Impact Factor
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    ABSTRACT: The aim of this study was to test the predictive value of interleukin (IL) 8 in the assessment of intestinal involvement in necrotizing enterocolitis (NEC). Forty infants with surgically treated NEC were classified into 3 groups based on intestinal involvement during laparotomy: focal (n = 11), multifocal (n = 16), and panintestinal (n = 13). Preoperatively obtained serum levels of IL-8, C-reactive protein, white blood cell count, and platelet count were correlated with intestinal involvement using logistic regression models. Interleukin 8 correlated significantly with intestinal involvement in infants with surgically treated NEC (odds ratio, 1.74; confidence interval, 1.27-2.39; P < .001). An exploratory IL-8 cutoff value of 449 pg/mL provided a specificity of 81.8% and sensitivity of 82.8% to discriminate focal from multifocal and panintestinal disease. An IL-8 cutoff value of 1388 pg/mL provided a specificity of 77.8% and a sensitivity of 76.9% to discriminate panintestinal disease from focal and multifocal disease. To our knowledge, this is the first study to demonstrate a significant correlation of IL-8 with intestinal involvement in advanced NEC in a large patient population. Our results indicate that IL-8 may be a promising biomarker for assessing intestinal involvement in infants with advanced NEC.
    Journal of Pediatric Surgery 08/2012; 47(8):1548-54. · 1.38 Impact Factor
  • R Hahn, H Rinösl, M Neuner, S C Kettner
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    ABSTRACT: We conducted a prospective study to test the validity of a new continuous non-invasive blood pressure (NIBP) monitor (CNAP) (CNAP™ Monitor 500). One hundred patients undergoing elective surgery under general anaesthesia were included in the study after informed written consent. The CNAP finger cuffs were placed on the fingers of one arm, an arterial catheter was inserted into the same arm and data were recorded simultaneously. Agreement between invasive arterial pressure (IAP) and blood pressure obtained by CNAP was compared using the Bland-Altman method for repeated measurements. The data from the first 50 patients (software V3.0) were used to improve the software of the CNAP (software V3.5), which was then evaluated in another 50 patients. We defined a clinically acceptable agreement according to the standards of the American Association for the Advancement of Medical Instrumentation for NIBP measurements [limits of agreement (LOA) ± 15 mm Hg]. We analysed 524 878 paired measurements in 100 patients. The mean bias of the mean arterial pressure in the first 50 patients was -2.9 mm Hg (sd 10.6 mm Hg, LOA -23.7 to 17.9 mm Hg), and in the consecutive 50 patients (using software V3.5) the bias was -3.1 mm Hg (sd 9.5 mm Hg, LOA -21.6 to 15.4 mm Hg). The new CNAP monitor showed an agreement with the IAP that is promising but did not match our predefined criteria.
    BJA British Journal of Anaesthesia 02/2012; 108(4):581-5. · 4.24 Impact Factor
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    ABSTRACT: The establishment of peripheral venous access in infants is the most common invasive technique in paediatric anaesthesia. Venous puncture can be challenging due to the small size of vessels in this patient population. The present study was designed to investigate the practicability of ultrasound-guided vascular access to the great saphenous vein (GSV) at the level of the medial malleolus in infants ≤ 12 months. Ninety consecutive infants ≤ 12 months undergoing elective surgery were included in this prospective study and divided into two age groups (0-6 and 7-12 months). After anaesthesia induction with sevoflurane, an ultrasound investigation of both GSVs at the level of the medial malleoli was performed. Subsequently, venous access in one GSV was established under direct ultrasound control. Anatomical ultrasound data and success rates of venous accesses were analysed. While not deeper relative to the skin, the GSV was significantly larger in older infants. The success rate in infants ≤ 6 months was 96%, whereas in older infants, the success rate was 100%. The overall success rate in all infants was 98%. Ultrasound facilitates venous puncture of the GSV in the vast majority of infants ≤ 12 months. Direct visualization via ultrasound is a promising technique for the establishment of venous access in the GSV at the level of the medial malleolus in infants.
    BJA British Journal of Anaesthesia 02/2012; 108(2):290-4. · 4.24 Impact Factor
  • S C Kettner, H Willschke, P Marhofer
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    ABSTRACT: In recent decades, a number of studies have attempted to determine whether regional anaesthesia offers convincing benefits over general anaesthesia. However, today we interpret meta-analyses more carefully, and it remains unclear whether regional anaesthesia reduces mortality. However, regional anaesthesia offers superior analgesia over opioid-based analgesia, and a significant reduction in postoperative pain is still a worthwhile outcome. Recent developments in technical aspects of regional anaesthesia have the potential to provide significant advantages for many patients in all age groups. Moreover, studies focusing on specific outcomes have shown benefits for regional anaesthesia used for surgery and postoperative analgesia.
    BJA British Journal of Anaesthesia 12/2011; 107 Suppl 1:i90-5. · 4.24 Impact Factor
  • Harald Willschke, Stephan Kettner
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    ABSTRACT: Abdominal wall blocks are an effective regional anesthetic technique to provide sufficient analgesia in abdominal surgery. This article reviews the use of abdominal wall blocks in pediatric regional anesthesia.
    Pediatric Anesthesia 11/2011; 22(1):88-92. · 2.44 Impact Factor
  • Peter Marhofer, Harald Willschke, Stephan C Kettner
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    ABSTRACT: Brachial plexus blockade in children can be used for a broad spectrum of clinical indications. Nevertheless, these regional anesthetic techniques are still underused in pediatric anesthesia that is mainly because of insufficient descriptions of the particular techniques. Ultrasound guidance enables direct visualization of neuronal and adjacent anatomical structures, the cannula, and the spread of local anesthetic. The most important issue in this context is theoretical background knowledge and intensive training of hand skills. The following review article discusses all relevant aspects of ultrasound-guided brachial plexus blockade.
    Pediatric Anesthesia 11/2011; 22(1):65-71. · 2.44 Impact Factor
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    ABSTRACT: The transversus abdominis plane (TAP) block is a regional anesthetic technique used for pain control following abdominal surgical procedures. While a minimum of systemic side effects is usually expected after local anesthesia, it is unknown to which extent systemic absorption and redistribution to the abdominal wall contributes to the effects of anesthetics. The aim of this study was to determine concentration-time profiles of ropivacaine after the injection of 150 mg of ropivacaine into the lateral abdominal wall in various compartments. The microdialysis technique was used to measure ropivacaine in plasma as well as at abdominal wall sites cranial from the injection site (below the 12th rip) and caudal from the injection site (cranial from the iliac crest) and in the skeletal muscle tissue of the contra lateral thigh of eight healthy volunteers. The mean exposure to ropivacaine measured as the area under the concentration-time curve was significantly higher at the two abdominal sites (240.9 ± 409.1 and 86.18 ± 133.50 μg h/mL, respectively) than in plasma (5.1 ± 1.0 μg h/mL) or in peripheral tissue (1.1 ± 1.2 μg h/mL). While the high mean concentrations of ropivacaine measured at the abdominal wall sites support the topical concept of the TAP block, the observed variability was striking. While the systemic pharmacokinetics was comparable between subjects, the local distribution of ropivacaine was highly variable after TAP block.
    European Journal of Clinical Pharmacology 10/2011; 68(4):419-25. · 2.74 Impact Factor
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    ABSTRACT: The present prospective volunteer study was designed to describe a technique for ultrasound identification of the medial antebrachial cutaneous nerve (MACN) and a technique for ultrasound-guided blockade of this sensory nerve of the upper limb. Twenty male volunteers were included in this study. After cross-sectional ultrasound identification of the MACN at the upper arm, where it is closely adjacent to the basilic vein, a selective blockade via an in-plane needle guidance technique was performed with 0.3 mL of mepivacaine 1.5% under direct ultrasound visualization. Sensory loss to pinprick at the upper extremity was evaluated and compared with the contralateral side. Constant ultrasound visualization of the MACN adjacent to the basilic vein at the upper arm level was possible in all cases. Blockade of the MACN under direct visualization was associated with a 100% success rate. The results of this investigation enable selective blockade of the MACN via ultrasound. Moreover, our data provide insight regarding the specific anatomic course and the integrity of this sensory nerve, which could be used for plastic and reconstructive surgical indications and for diagnosis of nerve injury.
    Regional anesthesia and pain medicine 08/2011; 36(5):499-501. · 4.16 Impact Factor
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    ABSTRACT: Despite the large amount of literature on caudal anaesthesia in children, the issue of volume of local anaesthetics and cranial spread is still not settled. Thus, the aim of the present prospective randomized study was to evaluate the cranial spread of caudally administered local anaesthetics in children by means of real-time ultrasound, with a special focus on the effects of using different volumes of local anaesthetics. Seventy-five children, 1 month to 6 yr, undergoing inguinal hernia repair or more distal surgery were randomized to receive a caudal block with 0.7, 1.0, or 1.3 ml kg(-1) ropivacaine. The cranial spread of the local anaesthetic within the spinal canal was assessed by real-time ultrasound scanning; the absolute cranial segmental level and the cranial level relative to the conus medullaris were determined. All the blocks were judged to be clinically successful. A significant correlation was found between the injected volume and the cranial level reached by the local anaesthetic both with regards to the absolute cranial segmental level and the cranial level relative to the conus medullaris. The main finding of the present study was positive, but numerically small correlation between injected volumes of local anaesthetic and the cranial spread of caudally administered local anaesthetics. Therefore, the prediction of the cranial spread of local anaesthetic, depending on the injected volume of the local anaesthetic, was not possible. EudraCT Number: 2008-007627-40.
    BJA British Journal of Anaesthesia 06/2011; 107(2):229-35. · 4.24 Impact Factor
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    ABSTRACT: Acupuncture for postoperative pain remains controversial. Potential sources of bias are failures in patient-blinding and therapist-patient interactions. Our study investigates the effects of electrical auricular acupuncture (AA) on postoperative pain in patients undergoing laparoscopy with an emphasis on patient-blinding and the exclusion of therapist-patient interactions. With institutional review board approval and written informed consent, we included 40 female patients undergoing laparoscopy. Patients were randomly assigned to receive AA (shen men, thalamus and one segmental organ-specific point) or electrodes only and an electrical stimulation device. All patients received this intervention under general anesthesia guaranteeing patient blinding and excluding therapist-patient interactions. Needles and devices were removed 72 hours postoperatively. Postoperatively, patients received 1,000 mg paracetamol every 6 hours. Additional piritramide was given on demand. A blinded observer obtained the VAS scores at 0, 2, 24, 48, and 72 hours as well as the postoperatively administered doses of piritramide. There was no difference in VAS scores or the consumption of piritramide during the first 72 hours postoperatively between groups (acupuncture versus placebo: 2.32 [1.40-3.25] versus 2.62 [1.89-3.36] average pain on VAS 0-10; 15.3 [12.0-18.6] mg versus 13.9 [10.5-17.3] mg piritramide). Values are expressed as mean [CI]. Our study shows no reduction in postoperative pain or an opioid sparing effect of auricular acupuncture in women undergoing laparoscopic procedures. Because we emphasized blinding of the patients and the exclusion of therapist-patient interactions, our study suggests that electrical auricular acupuncture has no effect on postoperative pain.
    Minerva anestesiologica 03/2011; 77(3):298-304. · 2.82 Impact Factor
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    ABSTRACT: To retrospectively describe the performance of ultrasound guided thoracic epidural anaesthesia under sedation for anaesthesia management of open pyloromyotomy. Anaesthesia management for hypertrophic pylorus stenosis (HPS) is usually performed under general anaesthesia with tracheal intubation. Only a few publications describe avoidance of tracheal intubation in infants by using spinal or caudal anaesthesia. The present retrospective analysis describes the performance of ultrasound guided thoracic epidural anaesthesia under sedation for anaesthetic management of open pyloromyotomy. Twenty consecutive infants scheduled for pyloromyotomy according to the Weber-Ramstedt technique were retrospectively analysed. After sedation with nalbuphine and propofol, an ultrasound guided single shot thoracic epidural anaesthesia was performed with 0.75 ml·kg(-1) ropivacaine 0.475%. Insufficient blockade was defined as increase of HR > 15% from initial value and/or any movements at skin incision. In those cases we were prepared for rapid sequence intubation according to the departmental standard. All pyloromyotomies could be performed under single shot thoracic epidural anaesthesia and sedation. One case of moderate oxygen desaturation was treated with intermittent ventilation via face mask. Thoracic epidural anaesthesia under sedation for pyloromyotomy has been a useful technique in this retrospective series of infants suffering from HPS. In 1/20 infants short term assisted ventilation via face mask was required. Undisturbed surgery was possible in all cases.
    Pediatric Anesthesia 02/2011; 21(2):110-5. · 2.44 Impact Factor
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    Peter Marhofer, Harald Willschke, Stephan Kettner
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    ABSTRACT: Ultrasound guidance for regional anesthesia has gained enormous popularity during the past several years. This review article highlights the importance of acquiring an understanding and knowledge of human anatomy for well tolerated and effective performance of regional anesthesia; includes description of some of the major principles of ultrasound-guided regional anesthesia techniques (adequate identification of neuronal and adjacent anatomical structures along with the procedure needle); use of adequate volumes of local anesthetic and the proper administration of local anesthetic; and discusses economical along with educational aspects of ultrasound-guided regional blocks. Recent studies by various authors have indicated that ultrasound-guided regional blocks can be performed by using smaller volumes of local anesthetics. Such findings will further contribute to the safety of regional anesthesia in daily clinical practice. Additional positive economical aspects associated with regional anesthesia have also been described in the recent literature. With little reservation, it is anticipated that ultrasound-guided regional anesthesia will become the 'GOLD' standard for performance of regional anesthesia. Excellent science and educational concepts will continue to be required with the continued increase in popularity of this exciting specialty of anesthesia.
    Current opinion in anaesthesiology 10/2010; 23(5):632-6.
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    ABSTRACT: Paravertebral blockade (PVB) is a regional anaesthetic technique with a large number of indications. PVB is usually performed with landmark-based techniques or methods that rely on pressure differences between the extra- and intraparavertebral space. This consecutive case series was designed to describe the ultrasound appearance of the lateral thoracic paravertebral space (PVS) and develop an ultrasound-guided method for PVB. The PVS of 20 women undergoing breast cancer surgery was investigated with a high-frequency linear ultrasound transducer in the sitting position. After identification of the transverse process, internal intercostal membrane (IIM), and pleura at the T3 and T6 levels, the depths of the IIM and pleura, and the sagittal diameter of the PVS were determined. An out-of-plane needle guidance technique was used to perform the PVB with ropivacaine 0.75% (12 ml) at both levels. Successful blockade was determined by the ability to perform surgery under light general anaesthesia without opioids. Appropriate ultrasound identification of the IIM, transverse processes, and pleura was possible in all cases. Correct placement of the tip of the needle in the PVS resulted in successful PVB. No correlations of morphometric data with ultrasound measurements of the PVS were detected. After ultrasound identification of the boundaries of the lateral PVS, an out-of-plane needle guidance technique facilitated successful PVB. There were no clinically relevant correlations between morphometric data and ultrasound measurements.
    BJA British Journal of Anaesthesia 10/2010; 105(4):526-32. · 4.24 Impact Factor
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    ABSTRACT: This prospective, observational volunteer study aimed to describe the appearance of the great auricular nerve using ultrasound and its blockade under ultrasound guidance. An in-plane needle guidance technique was used for blockade of the great auricular nerve with 0.1 ml mepivacaine 1%. Sensory block was evaluated by pinprick testing in comparison with the contralateral area propriae. The great auricular nerve was successfully seen in all volunteers and the tail of the helix, antitragus, lobula and mandibular angle were blocked in all cases whereas the antihelix and concha were never blocked. Ultrasound imaging of the great auricular nerve can be reliably achieved and successful blockade with minimal volumes of local anaesthetic is another example of the benefits of ultrasound-guided peripheral nerve blocks.
    Anaesthesia 08/2010; 65(8):836-40. · 3.49 Impact Factor
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    ABSTRACT: investigator either placed or did not place earplugs into the patients' ears (PLUG or noPLUG groups, respectively). Propofol requirements for stable sedation guided by the bispectral index and incidence of postoperative recall of intraoperative events were assessed in a double-blinded fashion. RESULTS: We found high but comparable propofol requirements in both groups (PLUG 4.4+/-1.2 vs. noPLUG 4.2+/-1.0 mg kg-1 h-1, p=NS). The incidence of intraoperative awareness was lower in the PLUG compared to the noPLUG group (16 vs. 56%; P<0.001). CONCLUSION: Although no sedative-sparing effect could be found in patients who wore earplugs during elective orthopedic surgery under spinal anesthesia, we nevertheless recommend using single-use paraffin wax earplugs. Beside their beneficial effect against potential harmful intraoperative noise, they reduce the incidence of intraoperative awareness with recall.
    Minerva anestesiologica 07/2010; 76(7):504-8. · 2.82 Impact Factor
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    ABSTRACT: Ultrasound guidance for regional anaesthesia has gained enormous popularity in the past decade. The use of ultrasound guidance for many regional anaesthetic techniques is common in daily clinical practice, and the number of practitioners using it is increasing. However, alongside the enthusiasm, there should be a degree of informed scepticism. The widespread use of the various techniques of ultrasound-guided regional blocks without adequate training raises the danger of malpractice and subsequent impaired outcome. Adequate education in the use of regional block techniques under ultrasound guidance is essential. This review article addresses ultrasound guidance for regional anaesthesia, and is divided into two parts because of the size of the topic and the number of issues covered. This first part includes a review and preview of ultrasound guidance in regional anaesthesia and discusses all aspects of ultrasound for regional anaesthesia with a focus on recent technical developments, the positive implications in economics, further potential advantages (e.g. detection of anatomical variants, painless performance of blocks) and education. It also attempts to define a 'gold standard' in regional anaesthesia with the most recent findings in adequate volumes of local anaesthetics for peripheral nerve blocks. This standard should include an extraneural needle position, a high success rate, and wide application of ultrasound guidance in regional anaesthesia. The second part describes the impact of ultrasound on the development of nerve block techniques in the past 5 yr.
    BJA British Journal of Anaesthesia 04/2010; 104(5):538-46. · 4.24 Impact Factor

Publication Stats

1k Citations
232.58 Total Impact Points

Institutions

  • 2013
    • IST Austria
      Klosterneuberg, Lower Austria, Austria
  • 2005–2012
    • Medical University of Vienna
      • Department of Clinical Pharmacology
      Wien, Vienna, Austria
  • 2009
    • King Saud University
      • College of Medicine
      Riyadh, Mintaqat ar Riyad, Saudi Arabia
  • 2008
    • Herz-Jesu Krankenhaus
      Wien, Vienna, Austria
  • 2006
    • University of Cape Town
      • Department of Anaesthesia
      Kaapstad, Western Cape, South Africa
  • 1999–2004
    • University of Vienna
      • Department of Anaesthesiology and General Intensive Care
      Wien, Vienna, Austria
  • 1999–2003
    • Vienna General Hospital
      Wien, Vienna, Austria
  • 1998
    • New York Presbyterian Hospital
      New York City, New York, United States