Der Anaesthesist
-
Thermodilution measurements of cardiac output (CO) by means of Swan-Ganz catheters, in a strict sense, represent pulmonary arterial blood flow (PBF). In principle, this is also true in the presence of intracardiac left-to-right shunts due to atrial or ventricular septal defects. However, early recirculation of indicator may give rise to serious methodological problems in these cases. ⋯ PBF at extremely high shunt ratios, however, cannot be assessed by monoexponential extrapolation in principle (Fig. 6). Insufficient elimination of indicator recirculation resulted in flow values that closely resembled systemic rather than PBF. This finding is in accordance with a mathematical analysis of the underlying Steward-Hamilton equation if an infinite number of recirculations would be
-
Clinical Trial
[Laryngeal surgery with a 3-D technique. Early results with the jet-laryngoscope in superimposed high-frequency jet ventilation].
Surgery by three-dimensional (3D) endoscopy is being used routinely in abdominal surgery and, in special cases, in thoracic surgery; however, it has not been reported as being used in microlaryngeal surgery. METHODS. We inserted a 3-D endoscope into a jet laryngoscope and studied the pressure properties at the tip of the laryngoscope as well as intrapulmonary pressures while applying superimposed high-frequency jet ventilation. ⋯ In the clinical application of 3-D endoscopy via a jet laryngoscope, it was possible to achieve sufficient ventilation, inspection of the surgical field, and performance of the surgical procedure. A CO2 laser was used without changing the ventilation regime. Although technical alterations would be desirable for its application to microlaryngeal surgery, it is presently possible to safely use the 3-D endoscope via the jet laryngoscope for microlaryngeal surgery, presenting the surgeon with new possibilities in voice-improving microsurgery of the larynx.
-
In order to assess the significance of drug levels measured in clinical and forensic toxicology as well as for therapeutic drug monitoring (TDM), it is essential that good collections of data are readily available. For more than 400 frequently used drugs therapeutic and, if data were available, toxic and fatal plasma concentrations as well as elimination half-lives were compiled in a table including, e.g., hypnotics like barbiturates and benzodiazepines, neuroleptics, antidepressants, sedatives, analgesics, anti-inflammatory agents, antihistamines, anti-epileptics, beta-adrenergic antagonists, antibiotics (penicillins, cephalosporins, aminoglycosides, gyrase inhibitors), diuretics, calcium-channel blockers, cardiac glycosides, anti-arrhythmics, anti-asthmatics, angiotensin converting enzyme inhibitors, opioid agonists, and local anaesthetics. ⋯ The range of (or single) half-life values given for each drug are chosen to represent the terminal log-linear phase at most. In addition to the assessment of significance of drug levels for the therapeutic monitoring of patients, this list can assist the diagnostic assessment in cases of intoxication.
-
Clinical Trial
[Axillary blockade of the brachial plexus. A prospective study of blockade success using electric nerve stimulation].
Axillary block is a common anesthetic technique for operations on the hand and forearm. In our hospital, with many trainees in anaesthesia, only 250-300 axillary blocks per year are performed by about 30 colleagues. This implies a small number of blocks for each anaesthetist. ⋯ Prior to injection of the local anaesthetic, the current for nerve stimulation should be reduced to < 0.5 mA. The time between the end of injection and the beginning of surgery should be no less than 30 min because complete sensory blockade can more often be achieved. The dose of mepivacaine should be no less than 6 mg/kg body weight.
-
Acute upper gastrointestinal bleeding in ICU patients has many possible causes: ulcer, adverse drug effects, gastric tube lesion, acute renal or liver failure, or stress-induced gastric mucosal lesion. Stress-induced gastric mucosal lesions typically are multiple superficial erosions, while ulcerations typically occur in patients with head trauma, neurosurgical operation or severe burns. Head trauma and neurosurgical patients are the only ones with increases gastric acid secretion; in general reduced acid secretion can be observed in ICU patients. ⋯ Active acid secretion depends on sufficient oxygen supply and mucosal ATP content. Hypotension and shock results in gastric mucosal ischaemia. These are the most important risk factors of stress bleeding.