Papers by Joachim Schmeck
Ains Anasthesiologie Intensivmedizin, Aug 1, 1997
The endothelins (ETs) are a family of three vasoactive peptides (ET-1, ET-2, ET-3) that were firs... more The endothelins (ETs) are a family of three vasoactive peptides (ET-1, ET-2, ET-3) that were first described in 1988. ETs have a wide range of action including vasoconstriction, vasodilatation, bronchoconstriction, and mitogenesis. Two types of ET receptors, classified as ETA and ETB receptors, have been identified in gene technology. Endothelins are produced by endothelial cells, smooth muscle cells, and bronchial epithelial cells. Their vasoactive effects contribute not only to homoeostasis but ETs seem also to be involved in several pulmonary diseases. Elevated ET plasma levels have been found in patients suffering from asthma, pulmonary fibrosis, pulmonary hypertension, and acute lung injury. This review gives a short summary of the actual facts in endothelin research, focussing on the effects of ET-1 in pulmonary circulation.
American Journal of Infection Control, 2015
This single-center study prospectively assessed the microbial contamination of anesthetic syringe... more This single-center study prospectively assessed the microbial contamination of anesthetic syringes handled perioperatively under different conditions. We documented high rates of bacterial contamination, with strong but statistically nonsignificant differences between handling groups. Our results identify skin contact as the main source of contamination, and thus we emphasize the impact of proper hand hygiene.
Shock (Augusta, Ga.), 2001
Heme oxygenase (HO) plays a pivotal role for the maintenance of liver blood flow and hepatocellul... more Heme oxygenase (HO) plays a pivotal role for the maintenance of liver blood flow and hepatocellular integrity after hemorrhagic shock. We investigated the role of Kupffer cells and neutrophils as paracrine modulators of hepatocellular HO-1 gene expression in a rat model of hemorrhage and resuscitation. Male Sprague-Dawley rats (n = 6-10/group) were anesthetized (pentobarbital, 50 mg/kg intraperitonal) and subjected to hemorrhagic shock (mean arterial blood pressure: 35 mmHg for 60 min) or a sham protocol. Based on the time course of HO-1 gene expression, the effect of various antioxidants, Kupffer cell blockade [gadolinium chloride (GdCl3); 10 mg/kg; 24 h prior to hemorrhage or dichloromethylene diphosphonate (Cl2MDP); 1 mg/kg; 2 days prior to hemorrhage], or neutrophil depletion (vinblastine, 0.5 mg/kg, 5 days prior to hemorrhage) on induction of the HO-1 gene was assessed at 5 h of resuscitation, i.e., the time point of maximal induction. Kupffer cell blockade and antioxidants abo...
Shock, 2001
Heme oxygenase (HO) plays a pivotal role for the maintenance of liver blood flow and hepatocellul... more Heme oxygenase (HO) plays a pivotal role for the maintenance of liver blood flow and hepatocellular integrity after hemorrhagic shock. We investigated the role of Kupffer cells and neutrophils as paracrine modulators of hepatocellular HO-1 gene expression in a rat model of hemorrhage and resuscitation. Male Sprague-Dawley rats (n = 6-10/group) were anesthetized (pentobarbital, 50 mg/kg intraperitonal) and subjected to hemorrhagic shock (mean arterial blood pressure: 35 mmHg for 60 min) or a sham protocol. Based on the time course of HO-1 gene expression, the effect of various antioxidants, Kupffer cell blockade [gadolinium chloride (GdCl3); 10 mg/kg; 24 h prior to hemorrhage or dichloromethylene diphosphonate (Cl2MDP); 1 mg/kg; 2 days prior to hemorrhage], or neutrophil depletion (vinblastine, 0.5 mg/kg, 5 days prior to hemorrhage) on induction of the HO-1 gene was assessed at 5 h of resuscitation, i.e., the time point of maximal induction. Kupffer cell blockade and antioxidants abolished HO-1 mRNA and protein induction after hemorrhage, while neutrophil depletion failed to affect hepatocellular HO-1 gene expression. In addition, Kupffer cell blockade aggravated hepatocellular injury. N-formyl-methionine-leucyl-phenylalanin (fMLP) induced a substantial influx of neutrophils into the liver but failed to induce hepatocellular HO-1 mRNA expression. These data suggest that Kupffer cells but not neutrophils induce an adaptive hepatocellular stress response after hemorrhage and resuscitation. Oxygen-free radicals released by Kupffer cells may serve as paracrine regulators of a hepatocellular stress gene which is necessary to maintain liver blood flow and integrity under stress conditions.
Rhinologic and Sleep Apnea Surgical Techniques, 2007
Stroke, 2000
Background and Purpose —The most potent vasoconstrictor known, endothelin-1, is currently conside... more Background and Purpose —The most potent vasoconstrictor known, endothelin-1, is currently considered to mediate cerebral vasospasm in subarachnoid hemorrhage (SAH), which can cause delayed cerebral ischemia. In our study, we performed clinical and in vitro experiments to investigate the origin and the mechanisms of the secretion of endothelin-1 in SAH. Methods —Endothelin-1 and markers of inflammatory host response (interleukin [IL]-1β, IL-6, and tumor necrosis factor-α) were comparatively quantified in the cerebrospinal fluid (CSF) of SAH patients and control subjects, and concentrations were related to clinical characteristics. Furthermore, mononuclear leukocytes isolated from the CSF of SAH patients and control subjects were analyzed regarding their mRNA expression of endothelin-1 and inflammatory cytokines. Finally, complementary in vitro experiments were performed to investigate whether coincubation of blood and CSF can trigger leukocytic mRNA expression and release of these fa...
Shock, 1998
The underlying mechanisms of hemoglobin (Hb)-induced vasoconstriction are not yet well understood... more The underlying mechanisms of hemoglobin (Hb)-induced vasoconstriction are not yet well understood. The aim of this study was to elucidate the influence of nitric oxide (NO) and endothelin (ET) on Hb-induced pulmonary vasoconstriction. Therefore, an autologous Hb preparation was administered into isolated rabbit lungs, in which pulmonary artery pressure (PAP) and weight gain was monitored. Either glyceroltrinitrate (GTN; 10(-5) M; n=6), L-arginine (10(-2) M; n=6), L-NAME (10(-4)M; n=6), ET(A)- or ET(B)-receptor antagonists (BQ,23, 10 6M, n=6) or (BQ788, 10(-6) M, n=6) were added to the perfusion fluid and NOx and thromboxane A2 levels were measured. In the control group the Hb-stimulation resulted in a pressure response up to 25.1+/-2.1 mmHg (p < .05), which was 136+/-6% of the reference value. The PAP increase was significantly (p < .05) blunted after GTN (71+/-5%), L-arginine (93+/-6%) and BQ788 (88+/-7%). Pretreatment with L-NAME (139+/-13%) or BQ123 (115+/-9%) did not show significant changes in PAP. The reduction of the Hb-induced pulmonary hypertension by NO-donors points toward the inactivation of NO by free hemoglobin. Likewise, ET(B)-receptor mediated vasoconstrictive effects without changes in NOx concentrations seem to play a pathogenetic role in the Hb-induced pulmonary vasoconstriction.
Regional Anesthesia and Pain Medicine, 2006
Local anesthetics (LAs) possess a variety of effects that cannot be explained by the typical bloc... more Local anesthetics (LAs) possess a variety of effects that cannot be explained by the typical block of neuronal sodium channels. Antithrombotic effects of LAs are well known, but LAs also act as bactericides. Therefore, an investigation of the influence of LAs on the inflammatory response of the isolated rat lung (n = 78) to an N-formyl-l-leucin-methionyl-l-phenylalanine (FMLP) stimulus was performed. The experiments were performed on isolated and ventilated rat lungs perfused with cell-free and plasma-free buffer. LAs (lidocaine and mepivacaine) were injected in various concentrations before application and activation of human granulocytes by FMLP. Pulmonary arterial pressure (PAP) and lung weight gain were monitored continuously. LAs in final dosages from 10(-2) to 10(-7) mg/kg body weight (n = 6 each) were injected into the pulmonary artery before treatment with FMLP (10(-6) M) to induce pulmonary arterial hypertension. Perfusate samples were taken intermittently to determine thromboxane A(2) (TX A(2)) and endothelin-1 concentrations. Microscopic analyses were performed to assess the degree of lung injury. Pretreatment with LAs significantly reduced the FMLP-induced PAP increase (treatment group v sham group: 0.5 to 5 mm Hg v 8 mm Hg; P < .05) and the release of endothelin-1 (2.4 v 5 fmol/mL). Histologic damage seen as acute granulocytic alveolitis was reduced by lidocaine and mepivacaine, even below clinically relevant concentrations. LA pretreatment reduces inflammatory reactions after FMLP stimulus.
Journal of Neurology, Neurosurgery & Psychiatry, 2001
Subarachnoidal release of inflammatory cytokines (interleukin (IL)-1 , IL-6, and tumour necrosis ... more Subarachnoidal release of inflammatory cytokines (interleukin (IL)-1 , IL-6, and tumour necrosis factor (TNF)-) was characterised in 35 patients with subarachnoid haemorrhage (SAH) and control subjects and compared with development of complicating haemodynamic abnormalities in basal cerebral arteries and clinical outcome. Serial analysis allowed the observation of a subacute response profile of these key mediators of inflammation in the subarachnoidal space. This compartmentalised inflammatory host response was closely associated in time and extent with development of increased blood flow velocities in the basal cerebral vessels as recorded by transcranial Doppler sonography. Moreover, intrathecal secretion of inflammatory cytokines was significantly increased in patients with poor clinical outcome. Together, these findings suggest a role of excessive compartmentalised inflammatory host response in pathogenesis of cerebrovascular complications after SAH.
Journal of Histochemistry & Cytochemistry, 1999
Mitochondrial carbonic anhydrase V (CA V) in liver provides HCO 3 Ϫ to pyruvate carboxylase for t... more Mitochondrial carbonic anhydrase V (CA V) in liver provides HCO 3 Ϫ to pyruvate carboxylase for the first step in gluconeogenesis and HCO 3 Ϫ to carbamyl phosphate synthetase I for the first step in ureagenesis. Because carbamyl phosphate synthetase I and ornithine transcarbamylase are also expressed in enterocytes, we tested the hypothesis that CA V is expressed in the gastrointestinal tract in addition to liver. Polyclonal rabbit antisera were raised against a polypeptide of 17 C-terminal amino acids of human CA V and against purified recombinant mouse isozyme and were used in Western blotting and immunoperoxidase staining of human and rat tissues. Immunohistochemistry showed that CA V is expressed cell-specifically in the alimentary canal mucosa from stomach to rectum. Immunoreactions for CA V were detected in the parietal cells and gastrin-producing G-cells of the stomach and in intestinal enterocytes. Western blotting of human and rat gastrointestinal tissues with isozyme-specific antibodies showed positive signals for CA V with the expected molecular mass. The findings in human tissues paralleled those in rat. The cell-specific pattern of CA V expression suggests a role for CA V in alimentary canal physiology. We propose that mitochondrial CA V participates in the detoxification of ammonia produced in the gastrointestinal tract by providing bicarbonate to carbamyl phosphate synthetase I.
Intensive Care Medicine, 1998
Objective: It is well Conclusions: The acute pressure reaction after air embolism is mainly media... more Objective: It is well Conclusions: The acute pressure reaction after air embolism is mainly mediated via ET-1 by an ET A receptor related mechanism. TXA 2 seems to maintain this reaction for a longer time.
European Journal of Anaesthesiology, 2007
Tissue depletion of adenosine during endotoxaemia has previously been described in the lung. Ther... more Tissue depletion of adenosine during endotoxaemia has previously been described in the lung. Therapeutic approaches to prevent adenosine depletion and the role of A1 and A2 receptor agonists, however, have not been investigated until now. In isolated and ventilated rabbit lungs, it was tested whether pretreatment with adenosine A1 agonist 2-chloro-N6-cyclopentyladenosine (CCPA; 10(-7) mol, n = 6) or A2 receptor agonist 5'-(N-cyclopropyl)-carboxyamido adenosine (CPCA; 10(-7) mol, n = 6) prior to injection of lipopolysaccharide (LPS) (500 pg mL-1) influenced pulmonary artery pressure (PAP), pulmonary energy content and oedema formation as compared with controls, solely infused with LPS (n = 6). Release rates of adenosine and uric acid were determined by high-performance liquid chromatography. Pulmonary tissue concentrations of high-energy phosphates were measured and the adenine nucleotide pool, adenosine 5'-triphosphate (ATP)/adenosine 5'-diphosphate (ADP) ratio and adenylate energy charge of the pulmonary tissue were calculated. Administration of LPS induced increases in PAP within 2 h up to 20.8 +/- 2.9 mmHg (P < 0.01). While pretreatment with the A1 agonist merely decelerated pressure increase (13.8 +/- 1.1 mmHg, P < 0.05), the A2 agonist completely suppressed the pulmonary pressure reaction (9.6 +/- 1.0 mmHg, P < 0.01). Emergence of lung oedema after exclusive injection of LPS up to 12.0 +/- 2.9 g was absent after A1 (0.6 +/- 0.5 g) and A2 (-0.3 +/- 0.2 g) agonists. These observations were paralleled by increased adenosine release rates compared with LPS controls (P < 0.05). Moreover, tissue concentrations of ADP, ATP, guanosine 5'-diphosphate, guanosine 5'-triphosphate, nicotinamide-adenine-dinucleotide and creatine phosphate were significantly reduced after LPS. Consequently, the calculated tissue adenine nucleotide pool and the adenylate energy charge increased after adenosine receptor stimulation (P = 0.001). Adenosine A1- and A2-receptor agonists reduced LPS-induced vasoconstriction and oedema formation by maintenance of tissue energy content. Thus, adenosine receptor stimulation, in particular of the A2 receptor, might be beneficial during acute lung injury.
European Journal of Anaesthesiology, 2005
An anti-inflammatory effect of alpha2-adrenoreceptor agonists has been suggested. Phospholipase A... more An anti-inflammatory effect of alpha2-adrenoreceptor agonists has been suggested. Phospholipase A2 is a key enzyme in the production of precursors of inflammatory lipid mediators. The aim of the present study was to investigate the effect of clonidine on phospholipase A2 activity in an established in vitro model. Human being platelet membranes containing active phospholipase A2 were exposed to buffer control or to three increasing concentrations of clonidine. Phospholipase A2 was measured by a radioisotope technique. A massive increase in phospholipase A2 activity was measured after clonidine exposure leading to final values of 92.5 +/- 3.1 pmol mg protein(-1) min(-1) (4.5-fold higher than control values; P < or = 0.01 vs. control). After clonidine exposure the maximal reaction velocity increased, while the Michaelis-Menten constant did not change. The Lineweaver-Burk representation suggested an interaction of clonidine with the phospholipase A2-substrate complex as well as the phospholipase A2 molecule. We conclude that the putative anti-inflammatory effect of clonidine was not caused by inhibition of phospholipase A2.
European Journal of Anaesthesiology, 2004
Background and Goal of Study: LMA-Unique (LMU, LMA Company) and SoftSeal (SS, Portex) are two sin... more Background and Goal of Study: LMA-Unique (LMU, LMA Company) and SoftSeal (SS, Portex) are two single-use laryngeal mask airways that can be used for ventilation during elective interventions. The two devices are compared for ease of insertion and quality of airway seal in a prospective clinical trial. Materials and Methods: After obtaining approval of the local ethics committee and patient consent, 30 women scheduled for elective short gynaecologic interventions, were randomized to be ventilated with either LMU or SS. After induction of general anaesthesia with fentanyl and propofol, airway devices were placed according to manufacturer´s instructions. Number of attempts (maximum 2), insertion time, time until first tidal volume and intraoperative tidal volumes with an etCO 2 of 35 mmHg were recorded. Airway leak pressure was measured with cuff pressures set to 60 cmH 2 O. After removal, devices were inspected for traces of blood and patients were questioned for hoarseness or soar throat. Results and Discussions: 15 women were ventilated with LMU and 15 with SS. Demographic data as well as baseline heart rate, blood pressure and peripheral oxygen saturation were comparable for both groups, mean age was 33.7(±12) years for LMU and 41.1(±18) years for SS. Insertion was successful in all patients, a second attempt was necessary in 2 patients with LMU and 1 patient with SS. Insertion time and time until first tidal volume were 15.4(±5.7)/17.2(±13.1) and 21.8(±8.5)/27.1(±13.4) seconds for LMU/SS. Peak airway pressures were 16.0 and 17.1 cmH 2 O with tidal volumes of 8.9 and 8.0 ml/kg for LMU and SS. Airway leak pressure with SS was higher than with LMU: 23.6(±4.4) vs. 20.9(±2.0) cmH 2 O (p=0.025). Anaesthesia time was 36.1 min for LMU and 41.7 min for SS. Traces of blood after removal were found in 1 SoftSeal patient. Mild complaints (2 on a ten point VAS scale) of trouble swallowing were stated in the recovery room and after 24 hours by one patient in the LMU group. Conclusion(s): Both laryngeal mask airways allow sufficient ventilation in the patients studied. The airway leak pressure, serving as an estimate to judge quality of airway seal, is higher with the SoftSeal laryngeal mask. Acknowledgements: LMA-Unique was provided by LMA Company and SoftSeal by Portex.
European Journal of Anaesthesiology, 2004
European Journal of Anaesthesiology, 2004
Background and Goal of Study: The oesophageal-tracheal Combitube (Kendall), the Easytube (Ruesch)... more Background and Goal of Study: The oesophageal-tracheal Combitube (Kendall), the Easytube (Ruesch) and the Laryngeal Tube Suction LTS (VBM) are three similar looking airway devices with a large proximal (pharyngeal) cuff and a smaller distal cuff. The single use Combitube and EasyTube allow ventilation in oesophageal and tracheal position, the tip of the reusable LTS has to be placed in the oesophageal inlet. Ventilation with the three devices is compared with tracheal tube ventilation in a bench model. Materials and Methods: 3-minute ventilation cycles (10 per device, total 60 cycles) were performed with tracheal tube (7.5), Combitube (37 Fr., tracheal and oesophageal position), Easytube (41 Fr., tracheal and oesophageal position) and LTS (#4) in a bench model consisting of a Ambu Megacode Station connected to a PC (Megacode software 2.23). Standardised ventilation (intermittent positive pressure ventilation, respiratory rate 12 per minute, tidal volume 750 ml) was performed with a Draeger Oxylog 3000 (Draeger medical). Cuff pressures were adjusted to 80 cm H 2 O. Tidal volumes and peak airway pressures were measured. The t-test was used for statistical analysis of the data. Results and Discussions.: No gastric insufflation of air could be detected with any device. Tidal volumes (mean±SD) and peak airway pressures for the airway devices were 730±7 ml and 15.8 cmH 2 O for tracheal tube, 733±6 (+0.4%) and 16.7* cmH 2 O for Combitube in oesophagal position, 708*±3 (-3.0%) and 17.6* cmH 2 O for Combitube in tracheal position, 733±3 (+0.4%) and 17.0* cmH 2 O for Easytube in oesophagal position, 742*±2 (+1.6%) and 16.8* cmH 2 O for Easytube in tracheal position, and 716*±6 (-1.9%) and 15.0* cmH 2 O for LTS (* = p<0.01 compared to ventilation with tracheal tube). Conclusion(s): In the bench model chosen, only small differences of tidal volumes are found for ventilation with Combitube, Easytube and LTS compared to ventilation with a tracheal tube. While some differences are significant, they may be of little clinical relevance considering the maximal deviation of 3%. Differences for ventilation in oesophageal and tracheal position may be caused by the variation of tube diameters.
Der Anaesthesist, 2003
Typ-I-Sensibilisierung auf Metamizol, die als ursächlich für das intraoperative Herz-Kreislauf-Ve... more Typ-I-Sensibilisierung auf Metamizol, die als ursächlich für das intraoperative Herz-Kreislauf-Versagen in Folge einer massiven anaphylaktischen Reaktion anzusehen ist.
Der Anaesthesist, 2010
Zusammenfassung Hintergrund Die Einführung des „Diagnosis-related-groups“- (DRG-)Systems erhöhte... more Zusammenfassung Hintergrund Die Einführung des „Diagnosis-related-groups“- (DRG-)Systems erhöhte den Kostendruck. Infolge des Zusammenwirkens vieler Berufsgruppen ist deshalb die Optimierung der Ablauforganisation im OP von zentraler Bedeutung. Fragestellung Ziel der Untersuchung war die Analyse der OP-Prozesse eines universitären Krankenhauses, um über die Identifizierung potenzieller Schwachstellen Optimierungsstrategien herzuleiten. Die umgesetzten Lösungen wurden erneut analysiert, um ihre Auswirkungen zu determinieren. Methode Im Beobachtungszeitraum von 6 Wochen vor
Uploads
Papers by Joachim Schmeck