Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 25
Filter
1.
Clin Hemorheol Microcirc ; 77(4): 355-365, 2021.
Article in English | MEDLINE | ID: mdl-33285628

ABSTRACT

BACKGROUND: Coronavirus disease 2019 (COVID-19) can cause acute respiratory distress syndrome (ARDS). OBJECTIVE: This single centre cross-section study aimed to grade the severity of pneumonia by bed-side lung ultrasound (LUS). METHODS: A scoring system discriminates 5 levels of lung opacities: A-lines (0 points),≥3 B-line (1 point), coalescent B-lines (2 points), marked pleural disruptions (3 points), consolidations (4 points). LUS (convex 1-5 MHz probe) was performed at 6 defined regions for each hemithorax either in supine or prone position. A lung aeration score (LAS, maximum 4 points) was allocated for each patient by calculating the arithmetic mean of the examined lung areas. Score levels were correlated with ventilation parameters and laboratory markers. RESULTS: LAS of 20 patients with ARDS reached from 2.58 to 3.83 and was highest in the lateral right lobe (Mean 3.67). Ferritin levels (Mean 1885µg/l; r = 0.467; p = 0.051) showed moderate correlation in spearman roh calculation. PaCO2 level (Mean 46.75 mmHg; r = 0.632; p = 0.005) correlated significantly with LAS, while duration of ventilation, Horovitz index, CRP, LDH and IL-6 did not. CONCUSIONS: The proposed LAS describes severity of lung opacities in COVID-19 patients and correlates with CO2 retention in patients with ARDS.


Subject(s)
COVID-19/diagnostic imaging , COVID-19/metabolism , Carbon Dioxide/metabolism , Adult , Aged , Cross-Sectional Studies , Female , Humans , Lung Diseases, Interstitial/diagnostic imaging , Lung Diseases, Interstitial/metabolism , Lung Diseases, Interstitial/virology , Male , Middle Aged , SARS-CoV-2/isolation & purification , Ultrasonography/methods
2.
Anaesthesist ; 69(2): 89-94, 2020 02.
Article in German | MEDLINE | ID: mdl-31820018

ABSTRACT

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are therapeutic options for the treatment of intra-abdominal neoplasms. Following the resection of all visible tumor areas by CRS, microscopic tumor areas are treated with HIPEC. This procedure increases the quality of life and survival. The CRS with HIPEC is a complex surgical procedure in which the mainly younger and often otherwise healthy patients undergo several pathophysiological changes during the operation. The main concern of the anesthesiologist is the massive volume loss, volume shift and metabolic alterations. Patients with a high comorbidity should undergo preoperative optimization to reduce the perioperative morbidity and mortality especially by protracted interventions.


Subject(s)
Abdominal Neoplasms/drug therapy , Abdominal Neoplasms/surgery , Cytoreduction Surgical Procedures , Hyperthermic Intraperitoneal Chemotherapy , Perioperative Care , Combined Modality Therapy , Humans
3.
Anaesthesist ; 68(10): 676-682, 2019 10.
Article in German | MEDLINE | ID: mdl-31595319

ABSTRACT

Dexamethasone is a synthetic steroid that has been used for many years in the clinical routine due to its anti-inflammatory, anti-allergic and immunosuppressive properties. Furthermore, dexamethasone has been used for a long time for prophylaxis and treatment of chemotherapy-induced nausea and vomiting. In the meantime dexamethasone has been approved as standard for the prophylaxis and treatment of postoperative nausea and vomiting (PONV). This review article outlines the indications and side effects of the perioperative administration of dexamethasone.


Subject(s)
Antiemetics/adverse effects , Antiemetics/therapeutic use , Dexamethasone/adverse effects , Dexamethasone/therapeutic use , Postoperative Nausea and Vomiting/drug therapy , Humans
4.
Anaesthesist ; 68(9): 594-606, 2019 09.
Article in German | MEDLINE | ID: mdl-31375866

ABSTRACT

Anesthesia services outside central surgical facilities (nonoperating room anesthesia, NORA) have become more important. Nonoperating room anesthesia is a challenging field with a wide range of patient ages and interventions. The anesthesiologist is caught between the existing expertise in sedation, respiratory and emergency management and the fact that it may be a potentially avoidable cost factor. The efforts of some specialist departments to carry out sedation themselves even with more complex interventions have therefore increased. In order to permanently establish anesthesia here, apart from the pure anesthesiological expertise, a pronounced willingness to interdisciplinary communication and cooperation is necessary. Only in this way can the participating specialist disciplines be convinced of the anesthesiological added value for the patient. Groups of patients requiring special attention include pediatric patients. The care especially for children under 2 years old also requires the particular anesthesiological expertise of the supervising anesthesiologist; however, profound knowledge, for example in cardiac anesthesia, is also required if special interventions are decentrally managed in the cardiac catheterization laboratory.


Subject(s)
Ambulatory Surgical Procedures , Anesthesia , Anesthesiologists , Child , Child, Preschool , Conscious Sedation , Humans
5.
Chirurg ; 89(9): 687-692, 2018 Sep.
Article in German | MEDLINE | ID: mdl-29971459

ABSTRACT

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are therapeutic options for the treatment of intra-abdominal neoplasms. Following the resection of all visible tumor areas by CRS, microscopic tumor areas are treated with HIPEC. This procedure increases the quality of life and survival. The CRS with HIPEC is a complex surgical procedure in which the mainly younger and often otherwise healthy patients undergo several pathophysiological changes during the operation. The main concern of the anesthesiologist is the massive volume loss, volume shift and metabolic alterations. Patients with a high comorbidity should undergo preoperative optimization to reduce the perioperative morbidity and mortality especially by protracted interventions.


Subject(s)
Cytoreduction Surgical Procedures , Hyperthermia, Induced , Peritoneal Neoplasms , Antineoplastic Combined Chemotherapy Protocols , Chemotherapy, Cancer, Regional Perfusion , Combined Modality Therapy , Humans , Peritoneal Neoplasms/therapy , Quality of Life , Survival Rate
7.
Anaesthesist ; 67(2): 93-108, 2018 02.
Article in German | MEDLINE | ID: mdl-29230500

ABSTRACT

BACKGROUND: Risk assessment prior to elective surgery is an important tool in the context of perioperative patient care; however, only a few studies have been carried out to address the processes and problems during preoperative assessment for anesthesia. AIM: Over a period of several weeks all preoperative anesthesia evaluations prior to elective surgery were prospectively recorded in order to generate a data pool with a view to identifying options for process optimization. MATERIAL AND METHODS: All preoperative evaluations over a period of 38 working days at the University Medical Center Regensburg were recorded and analyzed with respect to waiting time for the patient and the duration of the preoperative consultation on medication. Also documented were the patient age, ASA score, the faculty carrying out the operation, type and risk of surgery, planned time of surgery, professional experience of the anesthesiologist and the approval status for surgery. In addition, all problems which occurred during the preoperative anesthesia evaluation were documented using a questionnaire. RESULTS: Overall 2233 preoperative assessments for anesthesia were recorded and analyzed. The number of patients attending the preoperative assessment clinic differed markedly in the course of a day and was lower at the end of the week. Approval for surgery with no reservations was given more frequently by anesthesiologists with more than 5 years professional experience and consultants compared to younger colleagues. The main reason for approval with reservations or no approval was the lack of patient records and test results, which should have been presented according to the in-house standard for preoperative assessment for anesthesia. The mean waiting time was 58.6 ± 30.3 min, the mean duration of the patient documentation review and physician-patient consultation together was 33.6 ± 16.3 min. Anesthesiologists with 2-5 years professional experience needed significantly less time for patient documentation reviews and physician-patient consultations than younger and more experienced colleagues. The duration of the preoperative assessment for anesthesia correlated with the ASA score and risks of surgery. CONCLUSION: The analysis of processes and problems in the context of preoperative assessment for anesthesia revealed several options for optimization. Major efforts should be the implementation of an appointment system for the preoperative assessment clinic in order to generate a homogeneous distribution of patients during the course of a day. Furthermore, surgeons and case managers should be requested to refer patients to the preoperative assessment clinic only with complete records and test results according to the in-house standard.


Subject(s)
Anesthesia/mortality , Elective Surgical Procedures/methods , Preoperative Care/methods , Preoperative Care/standards , Anesthesia/standards , Hospitals, University , Humans , Perioperative Care , Physician-Patient Relations , Referral and Consultation , Risk Assessment , Surveys and Questionnaires
8.
9.
Anaesthesia ; 69(9): 1009-22, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24829066

ABSTRACT

Various experimental studies in animals have shown that general anaesthetics are potentially toxic to the developing brain. By inducing apoptosis or interfering with neurogenesis, anaesthetic exposure during a critical period of neuronal development can have significant impact on neurocognitive function later in life. It remains controversial whether these experimental results can be transferred to human beings and this is under intensive scientific evaluation. To gain more insight into possible neurotoxic effects on the human brain of infants and small children, a number of retrospective studies have been performed. At present, there is no clear evidence that exposure to anaesthesia up to the age of 3-4 years is associated with neurocognitive or behavioural deficits. Currently, the PANDA, MASK and GAS studies are underway to explore this relationship. Anaesthesia is not an end in itself, but necessary to facilitate surgical procedures. There is evidence that maintaining physiological conditions is important for the overall outcome following anaesthesia and surgery. Until proven otherwise, it can be recommended to keep anaesthesia and surgery as short as possible, to use short-acting drugs and/or a combination of general anaesthesia and multimodal pain therapy including systemic analgesics, and local or regional anaesthesia, to reduce the overall drug dosage.


Subject(s)
Anesthesia, General/adverse effects , Anesthetics, General/adverse effects , Brain/growth & development , Anesthesia, Conduction , Anesthetics, General/administration & dosage , Anesthetics, General/toxicity , Animals , Brain/drug effects , Child , Child, Preschool , Cognition/drug effects , Humans , Infant , Infant, Newborn , Nerve Degeneration/chemically induced , Nerve Degeneration/pathology , Neurotoxicity Syndromes
10.
Anaesthesist ; 62(2): 91-100, 2013 Feb.
Article in German | MEDLINE | ID: mdl-23392218

ABSTRACT

Many animal experiments have shown that anesthetics can have a neurotoxic effect on immature brains because they induce apoptosis and influence neurogenesis and synaptogenesis. In animal experiments this has substantial implications for the neurocognitive functions of animals in later life. Whether these results of animal experiments can be transferred to humans is currently the subject of intensive research. In several retrospective studies no clear association between anesthesia in premature babies, newborns or infants and the occurrence of learning disorders or behavioral problems could be found. The prospective studies GAS and PANDA are designed to obtain a deeper insight and if possible to clarify this problem. Because of the high relevance of this topic and in order to achieve more clarity for this problem when dealing with parents, the scientific working group for neuroanesthesia and pediatric anesthesia of the German Society for Anesthesiology and Intensive Care Medicine (DGAI) has formulated a position document on the basis of currently available data.


Subject(s)
Anesthetics, General/adverse effects , Neurotoxicity Syndromes/physiopathology , Anesthetics, General/pharmacology , Anesthetics, General/toxicity , Animals , Apoptosis/drug effects , Child, Preschool , Dose-Response Relationship, Drug , Drug Combinations , Female , Humans , Infant , Infant, Newborn , Infant, Premature , Male , Nerve Degeneration/chemically induced , Nerve Degeneration/pathology , Neurons/drug effects , Neuroprotective Agents/pharmacology , Neurotoxicity Syndromes/diagnosis
13.
Paediatr Anaesth ; 21(2): 104-9, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21210882

ABSTRACT

BACKGROUND: According to different algorithms of airway management, emergency cricothyrotomy is the final step in managing an otherwise not accessible airway. As an alternative to an open surgical procedure, minimally invasive approaches exist. Quicktrach baby™ is a commercially available set for a minimal invasive cricothyrotomy in infants. The set consists of a plastic cannula over a metal needle for direct placement in the trachea. So far, this device has not been evaluated for its intended use. OBJECTIVES: We hypothesize that Quicktrach baby™ allows the establishment of an emergency airway. The aim was to prove that the device is easy to handle and the cricothyrotomy fast to perform. METHODS: After approval of the local ethics committee, the study was performed on the cadavers of 10 adult rabbits. Cricothyrotomy was performed with Quicktrach baby™. Successful placement, performance time, and complication rate were documented. Possible ventilation with a breathing bag was evaluated. Data are reported as mean and interquartile range. RESULTS: Successful placement of Quicktrach baby™ was possible in all attempts. The placement took 31 [23-43] s. In two cases, a fracture of the cricoid's cartilage was seen. In one animal, damage to the posterior wall mucosa was observed. In all cases, sufficient ventilation was possible. CONCLUSIONS: Quicktrach™ baby proved to be a reliable technique. In the animal model, it is easy and fast to perform. Only a few minor complications occurred. Sufficient ventilation was possible in all attempts.


Subject(s)
Airway Management/instrumentation , Cricoid Cartilage/surgery , Emergency Medical Services , Laryngeal Muscles/surgery , Thyroid Cartilage/surgery , Animals , Catheters , Disease Models, Animal , Female , Humans , Infant , Infant, Newborn , Larynx/surgery , Needles , Rabbits , Respiration, Artificial , Trachea/surgery
14.
Anaesthesist ; 59(9): 781-805, 2010 Sep.
Article in German | MEDLINE | ID: mdl-20811729

ABSTRACT

Modern anesthesia is handling an increasing number of patients with neurological diseases who require narcosis. Regional anesthesia techniques offer qualities which might be advantageous for this group particularly for childbirth. The number of pregnant women with neurological diseases has increased significantly in the recent years due to improved diagnostics and therapy. A more careful approach to regional anesthesia in patients with neurological diseases is necessary as the drugs themselves possess neurotoxic effects and the procedure might worsen the underlying neurological diseases. Additionally, performing regional anesthesia might be more complicated and the resulting blockade might be different from the expected neuronal block. Published data concerning regional anesthesia in this patient group are limited and mainly restricted to case reports. In this review general considerations regarding regional anesthesia, techniques, drugs and methods in these patient groups will be discussed. In the second part the practical approach to regional anesthesia for some of the most important neurological diseases is highlighted.


Subject(s)
Anesthesia, Conduction , Nervous System Diseases/complications , Adjuvants, Anesthesia/adverse effects , Adult , Anesthesia, Obstetrical , Anesthetics, Local/adverse effects , Catheterization , Electric Stimulation , Female , Humans , Intracranial Pressure/physiology , Nerve Block , Pregnancy
15.
Acta Anaesthesiol Scand ; 53(5): 611-9, 2009 May.
Article in English | MEDLINE | ID: mdl-19419355

ABSTRACT

BACKGROUND: Analysis of critical incidents in anaesthesia practice emphasizes the important role of non-technical skills (NTS) in improving patient safety. Therefore, debriefing with regard to NTS has been added to medical management (MM) simulator training to improve acute crisis competencies of anaesthesiologists. The purpose of this study was to compare the NTS and MM performance of two groups of anaesthesiologists in a simulated anaesthesia crisis after undergoing different types of training. METHODS: Forty-two anaesthesiologists were randomly assigned to two different training groups, with each group participating in two simulation training sessions. One group's (NTS+MMG) training included extensive debriefing of NTS (resource management, planning, leadership and communication) and MM, while the other group (MMG) received a simpler debriefing that focused solely on MM. The quality and quantity of NTS and quality of MM performance were rated by reviewing the videotapes of the scenarios. RESULTS: NTS+MMG did not prove superior to MMG with regard to behavioural and MM markers. The quality of NTS performances correlated significantly (P<0.01) with the quantity of NTS demonstration, and also correlated significantly with the MM actions (P<0.01) in both groups. CONCLUSION: A single session of training including debriefing of NTS and MM did not improve the NTS performances of anaesthesiologists when compared with anaesthesiologists who only received MM training. This might indicate that a more frequent or individual training is needed to improve participants' NTS performance.


Subject(s)
Anesthesia , Anesthesiology/education , Clinical Competence , Patient Simulation , Adult , Attitude of Health Personnel , Case Management , Communication , Data Interpretation, Statistical , Emergencies , Female , Humans , Intraoperative Complications/therapy , Leadership , Male , Observer Variation , Patient Care Planning
16.
Handb Exp Pharmacol ; (182): 313-33, 2008.
Article in English | MEDLINE | ID: mdl-18175098

ABSTRACT

There are two optical isomers of the 2-(2-chlorophenyl)-2-(methylamino)-cyclohexanone ketamine: S(+) ketamine and R(-) ketamine. Effects of this drug are mediated by N-methyl-d-aspartate (NMDA), opioid, muscarinic and different voltage-gated receptors. Clinically, the anaesthetic potency of the S(+)-isomer is approximately three to four times that of the R(-)-isomer, which is attributable to the higher affinity of the S(+)-isomer to the phencyclidine binding sites on the NMDA receptors. Ketamine is water- and lipid-soluble, allowing it to be administered conveniently via various routes and providing extensive distribution in the body. Ketamine metabolism is mediated by hepatic microsomal enzymes. It causes bronchodilation and stimulation of the sympathetic nervous system and cardiovascular system. In clinics, ketamine and particularly S(+)-ketamine are used for premedication, sedation, and induction and maintenance of general anaesthesia, which is than termed "dissociative anaesthesia". Ketamine and its S(+)-isomer are ideal anaesthetic agents for trauma victims, patients with hypovolemic and septic shock and patients with pulmonary diseases. Even subanaesthetic doses of this drug have analgesic effects, so ketamine is also recommended for post-operative analgesia and sedation. The combination of ketamine with midazolam or propofol can be extremely useful and safe for sedation and pain relief in intensive care patients, especially during sepsis and cardiovascular instability. In the treatment of chronic pain ketamine is effective as a potent analgesic or substitute together with other potent analgesics, whereby it can be added by different methods. There are some important patient side-effects, however, that limit its use, whereby psycho-mimetic side-effects are most common.


Subject(s)
Analgesics/pharmacology , Anesthetics, Dissociative/pharmacology , Ketamine/pharmacology , Analgesics/administration & dosage , Analgesics/adverse effects , Anesthetics, Dissociative/administration & dosage , Anesthetics, Dissociative/adverse effects , Animals , Central Nervous System/drug effects , Contraindications , Dose-Response Relationship, Drug , Humans , Ketamine/administration & dosage , Ketamine/adverse effects , Pain/prevention & control , Substance-Related Disorders
17.
Br J Anaesth ; 99(5): 673-8, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17704088

ABSTRACT

BACKGROUND: In medicine, the use of standard operating procedures (SOPs) is often evaluated using questionnaires (QUES). However, QUES can have limitations with regard to method, thus leading to errors. Simulation (SIM) offers another opportunity for evaluation. We hypothesized that medical errors in the evaluation of SOPs using QUES could be detected by SIM, and that SIM is better qualified to demonstrate applied medicine. METHODS: We investigated the use of SOPs in anaesthesia, rapid sequence induction (RSI), by means of a QUES (n=42) or SIM (n=42) among 84 anaesthesiologists. Seven measures for preventing aspiration during induction of anaesthesia were examined and evaluated according to a predetermined points system. RESULTS: The average number of times that precautionary measures to prevent aspiration were mentioned in the QUES [4.8 (0.9)] or performed during SIM [5.0 (1.1)] did not differ between the two groups. Pre-oxygenation was the most frequently described or performed measure (95% vs 93%). However, other measures, such as avoidance of positive pressure ventilation (45% vs 85%), differed significantly between the two groups. CONCLUSIONS: QUES and SIM are powerful instruments for evaluating the implementation of SOPs such as RSI. SIM demonstrates automated behaviours and thus more clearly represents behaviours used in clinical practice than is possible to demonstrate using QUES. Using a combination of these two instruments, method errors resulting from the individual instruments can be reduced.


Subject(s)
Anesthesia/standards , Computer Simulation , Medical Errors/prevention & control , Pneumonia, Aspiration/prevention & control , Anesthesia/adverse effects , Clinical Competence , Critical Pathways/standards , Female , Humans , Intubation, Intratracheal/adverse effects , Intubation, Intratracheal/methods , Intubation, Intratracheal/standards , Male , Manikins , Oxygen Inhalation Therapy , Patient Simulation , Positive-Pressure Respiration , Safety Management/methods , Surveys and Questionnaires
18.
Anaesthesist ; 56(2): 118-27, 2007 Feb.
Article in German | MEDLINE | ID: mdl-17235544

ABSTRACT

Intramuscular injections of local anaesthetic agents regularly result in reversible muscle damage, with a dose-dependent extent of the lesions. All local anaesthetic agents that have been examined are myotoxic, whereby procaine produces the least and bupivacaine the most severe muscle injury. The histological pattern and the time course of skeletal muscle injury appear relatively uniform: hypercontracted myofibrils become evident directly after injection, followed by lytic degeneration of striated muscle sarcoplasmic reticulum myocyte edema and necrosis. Intriguingly, in most cases myoblasts, basal laminae and connective tissue elements remain intact which subsequently ensures complete muscular regeneration. Subcellular pathomechanisms of local anaesthetic myotoxicity are still not understood in detail. Increased intracellular Ca(2+) levels are suggested to be the most important element in myocyte injury, since denervation, inhibition of sarcolemmal Na(+) channels and direct toxic effects on myofibrils have been excluded as sites of action. Although experimental myotoxic effects are impressively intense and reproducible, only few case reports of myotoxic complications in patients after local anaesthetic administration have been published. In particular, the occurrence of clinically relevant myopathy and myonecrosis has been described after continuous peripheral blockades, infiltration of wound margins, trigger point injections, peribulbar and retrobulbar blocks.


Subject(s)
Anesthetics, Local/adverse effects , Muscular Diseases/chemically induced , Animals , Humans , Muscle, Skeletal/pathology , Muscle, Skeletal/ultrastructure , Muscular Diseases/epidemiology , Muscular Diseases/pathology , Muscular Diseases/physiopathology , Postoperative Complications/chemically induced , Postoperative Complications/epidemiology , Postoperative Complications/pathology
19.
Anaesthesist ; 56(1): 63-6, 68-70, 2007 Jan.
Article in German | MEDLINE | ID: mdl-17021884

ABSTRACT

BACKGROUND AND GOAL: Forced by the current economical situation, German hospitals have to reconsider their clinical productivity. When caregivers introduce new therapeutic concepts medical quality should either be improved without increasing costs or when reducing costs medical quality should be maintained. In the surgical field postoperative shivering reduces both patient comfort and medical quality. We therefore investigated the clinical pathway prevention of shivering with dolasetron in a prospective, randomized, placebo-controlled analysis of cost-effectiveness. MATERIAL AND METHODS: After written informed consent we randomized 40 patients scheduled for lumbar disc hernia repair or head and neck surgery into two groups: patients of group D received dolasetron 1 mg/kg body weight during surgery whereas patients of group K received 100 ml saline as placebo. Primary endpoints were the incidence of shivering, the length of stay in the postanesthesia care unit and process-associated costs. Secondary endpoint was the influence on perioperative thermoregulation. RESULTS: We observed postanesthetic shivering in 5 patients belonging to group D in comparison to 15 patients receiving the placebo (p<0.05). The length of stay in the postanesthesia care unit was shorter in patients allocated to dolasetron (mean+/-SD; group D: 43+/-16 min, group K 62+/-18 min, p<0.05). There was a significant saving in process-associated personnel costs (personnel costs in group D EUR 41.26+/-14, personnel costs in group K EUR 53.15+/-15) but in contrast the process-associated material costs were significantly increased (group D EUR 17.16+/-3, group K EUR 0.73+/-1, p<0.05). CONCLUSIONS: The optimization of the clinical process and medical quality induced by a prophylaxis against shivering and postoperative nausea and vomiting compensates for the increased use of pharmaceutical resources in our setting.


Subject(s)
Indoles/economics , Indoles/therapeutic use , Postoperative Complications/drug therapy , Postoperative Complications/economics , Quinolizines/economics , Quinolizines/therapeutic use , Shivering/drug effects , Adolescent , Adult , Aged , Analysis of Variance , Anesthesia , Body Temperature Regulation/drug effects , Cost-Benefit Analysis , Critical Care/economics , Endpoint Determination , Female , Germany , Head/surgery , Humans , Intervertebral Disc Displacement/complications , Intervertebral Disc Displacement/surgery , Length of Stay , Male , Middle Aged , Neck/surgery , Postoperative Nausea and Vomiting/epidemiology
20.
Acta Anaesthesiol Scand ; 50(6): 742-8, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16987371

ABSTRACT

BACKGROUND: Spontaneous Ca2+ -oscillations are a possible mechanism of Ca2+ -mediated signal transduction in neurons. They develop by a periodical interplay of Ca2+, which enters the neuron from the extracellular medium and triggers Ca2+ release from the endoplasmic reticulum (ER). Ca2+ -oscillations are terminated by reuptake into the ER or plasmalemmal extrusion. Spontaneous Ca2+ -oscillations are glutamate dependent and appear to be responsible for neuronal plasticity and integration of information. Here, we examined the role of the gamma-aminobutyric acid (GABAA) receptor on spontaneous Ca2+ -oscillations and studied the effects of the anaesthetics midazolam, thiopental and the non-anesthetic barbituric acid on spontaneous Ca2+ -oscillations. METHODS: Hippocampal neuronal cell cultures of 19-day-old embryonic Wistar rats 17-18 days in culture were loaded with the Ca2+ -sensitive dye Fura-2AM. Experiments were performed using dual wave-length excitation fluorescence microscopy and calibration constants were obtained from in situ calibration. RESULTS: Spontaneous Ca2+ -oscillations are influenced by the GABAA receptor. The intravenous anaesthetics midazolam and thiopental suppressed the amplitude and frequency reversibly in a dose-dependent manner with EC50 in clinically relevant concentrations. This effect was mediated via the GABAA receptor as it could be reversed by the GABAA receptor antagonist bicuculline. In contrast, the application of barbituric acid had no effects on the spontaneous Ca2+ -oscillations. CONCLUSION: Spontaneous Ca2+ -oscillations are influenced by the GABAA receptor. Spontaneous Ca2+ -oscillations might represent an interesting model system to study anaesthetic mechanisms on neuronal information processing.


Subject(s)
Anesthetics, Intravenous/pharmacology , Calcium Signaling/drug effects , Calcium/metabolism , Hippocampus/drug effects , Neurons/drug effects , gamma-Aminobutyric Acid/physiology , Animals , Barbiturates/pharmacology , Bicuculline/pharmacology , Calibration , Cells, Cultured , Dose-Response Relationship, Drug , Fluorometry , GABA Antagonists/pharmacology , GABA Modulators/pharmacology , Hippocampus/cytology , Midazolam/pharmacology , Rats , Rats, Wistar , Receptors, GABA-A/drug effects , Thiopental/pharmacology
SELECTION OF CITATIONS
SEARCH DETAIL
...