Biomedical subjects
Publications and source records attributed to E Voigt.
During storage of syringes changes can develop in the material possibly depending on surrounding conditions. This can lead to precipitation of oleic acid amide into the lumen of the syringe. This material floats in corpuscular form on the injection fluid.
A portable, battery powered blood pressure-pulse monitor is described. This device is suitable for direct monitoring of blood pressure and pulse frequency during operation, in the postoperative period as during inner clinical transport or aviation transport.
A rapid anaysis of parameters of the acid-base equilibrium and blood gases during open heart surgery and emergency therapy is absolutely necessary. Computing of the several parameters of the acid-base status by slide rules or nomograms is time consuming and can be shortened by computer applications. The central blood gas laboratory consists of a blood gas analyzer for PO2, PCO2 and pH, an electronic desktop calculator, a four color X-Y-plotter and two data lines to the cardiac surgery unit and to the intensive care unit. The time needed for computing and feedback of the parameters could be decreased to one quarter. In addition to numerical data printout, a graphical representation of the several parameters is possible on a X-Y-plotter and includes the Rahn-Fenn-O2-CO2-Diagram with venous admixture, ventilation perfusion ratio, alveolar dead space ventilation and the standard and actual oxygen dissociation curve as well as the pH/HCO3- Acid-Base nomogram. Furthermore, a computer diagnosis of the actual disturbances can be plotted.
During laparoscopy and intraabdominal insufflation of CO2 cardio-respiratory accidents following increased PaCO2 are possible. The continuous measurement of endexpiratory CO2-concentration by infrared absorption spectrometry is a simple method for controlling the level of ventilation. Respiratory acidosis under controlled artificial ventilation during laparoscopy can thus be avoided.
A case of acute renal insufficiency after therapy with gentamycin and beta-Aescin is reported. The role of these two agents in the causation of the acute renal failure is discussed. Renal function was restored using the REDY-Hemodialization System.
A new CO2-Analyzer for continuous measurement of CO2 content during artificial respiration is described. Based on infra red absorption, this device may be used for measuring the carbon dioxide content of expiration in anaesthesia and intensive care. Carbon dioxide infrared absorption is affected by nitrous oxide. This side effect can be compensated by a single switch, if the sample contans N2O.
A computer-assisted system for the calculation of derived blood-gas and acid-base parameters, consisting of an analysator (AVL 937) desk calculator (HP 9825A) and external printer (HP 5150A) is described. For the calculation of the derived parameters corrections were made for patient temperature, plasma protein, reduced haemoglobin and CO2-carbamino haemoglobin. The time needed for calculating and feed back was shortened.
The purpose of our investigations was to evaluate the influence of disturbed inspiratory gas distribution on postoperative hypoxemia in patients with abnormal lung function undergoing upper abdominal surgery. The lung function analyzer Hewlett-Packard 47402 A was used (Volume-time and flow-volume curves of forced expiration, single and multiple breath nitrogen washout tests with indices of ventilatory gas distribution). It was demonstrated that postoperative hypoxaemia in the undamaged lung is almost exclusively the result of augmented true right to left shunt. In patients with abnormal lung function the cause of postoperative hypoxaemia is, for the most part, an increase of disturbances of ventilatory gas distribution. These changes in the postoperative period can be explained by a reduction of FRC, that follows from changing of position (sitting-lying) and from pain. In patients with borderline lung function this reduction of FRC postoperatively may limit surgical treatment. The management of pain is of great importance in these patients. Continuous epidural anaesthesia certainly produces the best results in this respect.
A Mini-Photometer and a Mini-Centrifuge for determination of Hb and Hk are described. These devices are simple to use, compact in size and sufficiently accurate for clinical use in a variety of circumstances.
An uneven distribution of the inspiratory gas volume to the alveolar volume leads to disturbances of the ventilation/perfusion ratio VA/Q with resulting arterial hypoxemia. These ventilatory disturbances can be verified by nitrogen-washout-curves and an inspiratory gas distribution index derived from those curves. Preoperative diagnostic and the control of respiratory diseases during intensive therapy are possible without technical difficulties.
Difficulties and complications during artificial ventilation of prematures and newbornes gave rise to investigate the pressure-flow-characteritics during artificial respiration with the flow-time-cycled respirator Bennett PR-2 in combination with thin tracheal tubes. The flow and corresponding pressures generated by the respirator under different conditions were investigated. It is suggested that a sufficient respiration is not possible with a low generator pressure and high tidal frequencies under pathological conditions as it is often practised.