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Dive into the research topics where Alexander Dullenkopf is active.

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Featured researches published by Alexander Dullenkopf.


BJA: British Journal of Anaesthesia | 2009

Prospective randomized controlled multi-centre trial of cuffed or uncuffed endotracheal tubes in small children

Markus Weiss; Alexander Dullenkopf; J. E. Fischer; Christine Keller; Andreas C. Gerber

BACKGROUND The use of cuffed tracheal tubes (TTs) in small children is still controversial. The aim of this study was to compare post-extubation morbidity and TT exchange rates when using cuffed vs uncuffed tubes in small children. METHODS Patients aged from birth to 5 yr requiring general anaesthesia with TT intubation were included in 24 European paediatric anaesthesia centres. Patients were prospectively randomized into a cuffed TT group (Microcuff PET) and an uncuffed TT group (Mallinckrodt, Portex, Rüsch, Sheridan). Endpoints were incidence of post-extubation stridor and the number of TT exchanges to find an appropriate-sized tube. For cuffed TTs, minimal cuff pressure required to seal the airway was noted; maximal cuff pressure was limited at 20 cm H(2)O with a pressure release valve. Data are mean (SD). RESULTS A total of 2246 children were studied (1119/1127 cuffed/uncuffed). The age was 1.93 (1.48) yr in the cuffed and 1.87 (1.45) yr in the uncuffed groups. Post-extubation stridor was noted in 4.4% of patients with cuffed and in 4.7% with uncuffed TTs (P=0.543). TT exchange rate was 2.1% in the cuffed and 30.8% in the uncuffed groups (P<0.0001). Minimal cuff pressure required to seal the trachea was 10.6 (4.3) cm H(2)O. CONCLUSIONS The use of cuffed TTs in small children provides a reliably sealed airway at cuff pressures of <or=20 cm H(2)O, reduces the need for TT exchanges, and does not increase the risk for post-extubation stridor compared with uncuffed TTs.


Acta Anaesthesiologica Scandinavica | 2005

Fit and seal characteristics of a new paediatric tracheal tube with high volume–low pressure polyurethane cuff

Alexander Dullenkopf; Andreas C. Gerber; Markus Weiss

Background:  To evaluate a new paediatric tracheal tube (Microcuff, Weinheim, Germany) with an ultrathin high volume–low pressure polyurethane cuff.


Pediatric Anesthesia | 2005

Near-infrared spectroscopic cerebral oxygenation reading in neonates and infants is associated with central venous oxygen saturation

Markus Weiss; Alexander Dullenkopf; Anna Kolarova; Gabriele Schulz; Bernhard Frey; Oskar Baenziger

Background:  The aim of the study was to elucidate easily determinable laboratory and vital parameters in clinical practice to explain variability of near‐infrared spectroscopic cerebral oxygenation readings in critically ill newborns and infants using the NIRO 300 spectrometer.


Pediatric Anesthesia | 2003

Measurement of cerebral oxygenation state in anaesthetized children using the INVOS 5100 cerebral oximeter

Alexander Dullenkopf; Bernhard Frey; Oskar Baenziger; Andreas C. Gerber; Markus Weiss

Background: Near‐infrared spectroscopy is a developing technique for monitoring cerebral oxygenation during anaesthesia. The aim of this study was to evaluate absolute values of cerebral oxygenation during stable anaesthesia conditions in otherwise healthy children using the recently introduced INVOS 5100 cerebral oximeter with a paediatric and adult sensor and to compare them with values obtained from the NIRO 300 oximeter.


Anesthesiology | 2005

Continuous Infusion of Ropivacaine for Pain Relief after Iliac Crest Bone Grafting for Shoulder Surgery

Stephan Blumenthal; Alexander Dullenkopf; Katharina Rentsch; Alain Borgeat

Background:The aim of the study was to compare the efficacy of either ropivacaine or placebo through an iliac crest (IC) catheter after Bankart repair with IC bone grafting. Methods:With approval of the local ethics committee and after written informed consent was obtained, 36 patients had an interscalene catheter placed preoperatively. Intraoperatively, the surgeon placed a catheter at the IC donor site. At the end of surgery, 30 ml ropivacaine, 0.5% (ropivacaine group), or 30 ml NaCl, 0.9% (placebo group), was administered. Ropivacaine, 0.2%, was started 6 h after the initial block through the interscalene catheter for 48 h (t48) in all patients. At t0, the patient received either 5 ml/h ropivacaine, 0.2% (ropivacaine group), or 5 ml/h NaCl, 0.9% (placebo group), for 48 h through the IC catheter. All patients received an intravenous morphine patient-controlled analgesia device. Pain scores at the shoulder and at the IC donor site were assessed at rest and during motion every 8 h for 48 h and after 3 months. Plasma concentrations of total and unbound ropivacaine, morphine consumption, and patient satisfaction were assessed. Results:At the IC donor site, pain was significantly lower in the ropivacaine group compared with the placebo group at rest and during motion at any time. Total and unbound plasma concentrations of ropivacaine were below the toxic threshold in both groups. Morphine consumption was significantly lower in the ropivacaine group after 24 and 48 h. Patient satisfaction was significantly higher in the ropivacaine group. At 3 months, pain at the IC during motion was significantly lower in the ropivacaine group. Conclusions:Continuous application of 0.2% ropivacaine through an IC catheter after Bankart repair with IC bone grafting is an effective method for pain relief for the first 48 h, with few adverse effects and high patient satisfaction. The benefit of this technique is still present after 3 months.


Acta Anaesthesiologica Scandinavica | 2006

Evaluation of a new recommendation for improved cuffed tracheal tube size selection in infants and small children

B. Salgo; A. Schmitz; G. Henze; Katharina Stutz; Alexander Dullenkopf; S. Neff; Andreas C. Gerber; Markus Weiss

Background:  The purpose of this study was to evaluate a new recommendation for tracheal tube size selection using second‐generation Microcuff paediatric endotracheal tubes (PETs) with optimized outer diameter (OD) of the distal tube.


Pediatric Critical Care Medicine | 2005

Reproducibility of cerebral oxygenation measurement in neonates and infants in the clinical setting using the NIRO 300 oximeter.

Alexander Dullenkopf; Anna Kolarova; Gabriele Schulz; Bernhard Frey; Oskar Baenziger; Markus Weiss

Objective: To study reproducibility of cerebral tissue oxygenation index (cTOI) values in neonates and infants in a clinical setting using the NIRO 300 oximeter (Hamamatsu Photonics, Hamamatsu City, Japan). Design: Clinical, observational study. Setting: University hospital, pediatric intensive care unit. Patients: Twenty neonatal and pediatric intensive care patients (age 0–190 days; median 4.5 days). Interventions: Reproducibility of cTOI was measured at the lateral forehead of the patients. Measurements and Main Results: Sensor exchange experiments were performed by removing the sensor and reapplying another sensor (sensor 1 vs. sensor 2) at the same position. Simultaneous measurements, comparing cTOI values from the right and left forehead, were performed using both sensors. Corresponding sensor exchange experiments were performed within 10 mins. All tests were done under stable, steady-state cardiorespiratory conditions. Data were compared using Bland-Altman bias analysis and paired, two-sided Students t-test (p < .05). Sensor exchange experiments and simultaneous left-to-right forehead measurements revealed only small mean differences (<5%) and no significant differences between corresponding values (p = .953/.164). However, Bland-Altman bias analysis revealed poor agreement with large 95% limits of agreement in particular for sensor exchange experiments (−17.8% to 17.6%) and less for simultaneous left and right measurements (−14.4% to 10.4%). Conclusions: The present study shows that cTOI measurements using the NIRO 300 oximeter at the lateral forehead of neonates and infants are not well reproducible under clinical conditions. This raises the question whether generally valid normal values can be defined with the used approach and makes it difficult to determine a normal range of cerebral oxygenation.


Pediatric Anesthesia | 2006

Cuff filling volumes and pressures in pediatric laryngeal mask airways

Paulo Maino; Alexander Dullenkopf; Christian Keller; Markus Weiss

Background : Hyperinflation of LMA cuffs carries the risk of airway morbidity by exerting pressure on laryngeal and pharyngeal structures. Cuff hyperinflation in LMAs can result from nitrous oxide diffusion into the LMA cuff and from deliberate manual cuff inflation.


Expert Review of Medical Devices | 2007

Cuffed tracheal tubes in children: past, present and future

Markus Weiss; Alexander Dullenkopf

This article reviews recent developments and core topics in the use and design of pediatric cuffed tracheal tubes. A concept for an appropriate pediatric cuffed tracheal tube is introduced. The main points in this concept are evidence-based tracheal tube size recommendation, continuous cuff pressure monitoring and a pediatric tracheal tube with an anatomically-based intubation depth mark and a short distally placed high-volume–low pressure cuff made from an ultra-thin polyurethane membrane with markedly improved tracheal sealing performance. The main points in proper handling of cuffed tracheal tubes in children are highlighted. Finally, an outlook on future developments in the design of pediatric cuffed tracheal tubes and an overview of tasks to be performed in evaluating them is given.


Pediatric Anesthesia | 2004

Tracheal sealing characteristics of pediatric cuffed tracheal tubes

Alexander Dullenkopf; A. Schmitz; Andreas C. Gerber; Markus Weiss

Background : The aim of the study was to compare sealing characteristics of the new Microcuff pediatric tracheal tube featuring a high volume–low pressure (HVLP) cuff with ultrathin membrane with three conventional pediatric cuffed tracheal tubes.

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Markus Weiss

Boston Children's Hospital

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Andreas C. Gerber

Boston Children's Hospital

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A. Schmitz

Boston Children's Hospital

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Katharina Stutz

Boston Children's Hospital

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Oskar Baenziger

Boston Children's Hospital

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Vera Bernet

Boston Children's Hospital

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Walter Knirsch

Boston Children's Hospital

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Anna Kolarova

Boston Children's Hospital

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Bernhard Frey

Boston Children's Hospital

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