Die Verwendung eines Nervenstimulators zur sicheren Platzierung von Ilisarov-Drähten

OBJECTIVE: Avoidance of potential iatrogenic nerve injury during insertion of Ilizarov fine wires into areas of high anatomic risk by using a modified nerve stimulation technique. INDICATIONS: Application of the Ilizarov ring fixator to areas of high anatomic hazard, in situations where anatomic topography may be distorted by previous surgery, trauma, or congenital anomalies. CONTRAINDICATIONS: Use of systemic muscle relaxants. Caution in patient with cardiac pacemaker. SURGICAL TECHNIQUE: Preliminary experiments showed that a standard nerve-stimulating device can deliver a negatively charged, monophasic square pulse of current through Ilizarov wires. During the application of an Ilizarov frame to potentially hazardous anatomic regions, providing no systemic muscle relaxants are used, a voltage field sufficient to cause nerves in close proximity to the Ilizarov wire to depolarize is produced. Identification of a distal muscle twitch provoked by the stimulation may indicate a potential for iatrogenic nerve injury. RESULTS: Results show that with the nerve stimulator set at 2.5 mA (pulsed at a frequency of 2 Hz), peripheral nerves are stimulated if they lie within 5 mm of the wires. Should a distal muscle twitch occur, wires should be repositioned so that equivalent stimulation produces no twitch. The technique was used during Ilizarov frame application in ten patients, with only a single occurrence of distal muscle twitches in a lower-leg frame. Following repositioning of the Ilizarov wire in this case, no further twitches were observed, indicating that no Ilizarov wire was inserted close to peripheral nerves. No neurologic impairment was present postoperatively.     

Associated occurrence of persistent truncus arteriosus and asplenia

Summary An infant with persistent truncus arteriosus associated with splenic agenesis and the asplenia syndrome is reported, including clinical, echocardiographic and autopsy findings. To the authors' knowledge this association has not been previously reported.     

An assay of uroporphyrinogen decarboxylase in erythrocytes

Measurement of uroporphyrinogen decarboxylase (UROD; EC 4.1.1.37) activity in erythrocytes is useful in distinguishing between familial porphyria cutanea tarda (PCT), in which UROD activities are low, and acquired PCT, in which UROD activity is normal. In this method for measuring UROD, pentacarboxylic acid porphyrinogen I (PPI) is used as substrate. A sample of the patient's whole blood is incubated with PPI at 37 degrees C for 30 min at pH 6.0. The reaction is stopped by adding trichloroacetic acid/dimethyl sulfoxide containing mesoporphyrin (internal standard). The coproporphyrin so produced is measured directly by high-performance liquid chromatography, with fluorescence detection. Our values by this method for healthy subjects and non-PCT patients ranged from 1.8 to 4.0 U/L. The CV for the assay was 10% at 1.1 U/L and 9% at 2.4 U/L. Twelve of 42 patients with PCT had low erythrocyte UROD activities. In each of six families of patients with low UROD activity we found at least one other family member with a low UROD activity in erythrocytes.     

Does changing from mercury to electronic blood pressure measurement influence recorded blood pressure? An observational study.

Mercury sphygmomanometers have been commonly used in primary care to measure blood pressure but are associated with bias. Electronic blood pressure machines are being introduced in many practices and have anecdotally been associated with higher recorded blood pressure. This study examined recorded blood pressure in four practices before and after electronic blood pressure machine introduction. No consistent change in mean blood pressure was apparent following their introduction, but there was a large and significant fall in terminal digit preference suggesting improved precision of recording.     

Effect of linoleic and oleic acids on blood pressure, blood viscosity, and erythrocyte cation transport

It has been proposed that dietary linoleic acid lowers blood pressure (BP) by being converted to arachidonic acid and prostanoids of the two-ene series. We tested the effects of linoleic acid on plasma arachidonic acid, blood pressure, blood viscosity, and RBC cation transport. Oleic acid, the major dietary monounsaturated fat and which is not a prostanoid precursor, was used as a control. Seventeen adults consumed 23 g/d of linoleic acid or oleic acid provided by genetic variants of safflower seed, each for 4 weeks in a double-blind crossover design. Linoleic and oleic acids were enriched significantly in the plasma cholesteryl esters, phospholipids and triglycerides during the respective periods of supplementation but there was no increase in arachidonate. Mean BP was 116.1/76.8 during ingestion of oleic and 113.6/74.6 during ingestion of linoleic acid (p = 0.09 systolic, p = 0.12 diastolic). The power of the study was over 75% for detecting a significant (p less than 0.05) effect of 4 mm Hg in systolic BP or diastolic BP. Whole blood and plasma viscosity, and RBC Li/Na countertransport, Na/K cotransport, and Na pump systems (Vmax) were unchanged during the protocol. Therefore, variations in dietary linoleic or oleic acids are unlikely to have major effects on BP or on several membrane-dependent erythrocyte functions related to hypertension.     

Artificial dermis for major burns. A multi-center randomized clinical trial.

This communication presents an 11-center prospective randomized trial using the artificial dermis invented by Burke and Yannas. Patients with life-threatening burns who underwent primary excision and grafting within 7 days of injury had comparable sites randomized to receive either the artificial dermis (study site) or the investigator's usual skin grafting material (control site). Control materials were autograft, allograft, xenograft, or a synthetic dressing. Epidermal grafts were applied to the study site during a second operation, and surviving patients were followed for 1 year after grafting. One hundred thirty-nine sites on 106 patients were studied. Mean burn size was 46.5 +/- 15% mean total body surface (TBSA). Overall mortality was 13%, and mean hospital stay was 68 +/- 45 days. Median artificial dermis take was 80% compared with 95% for all comparative sites, but the take was equivalent to that of all nonautograft control materials. Results with the artificial dermis improved slightly as the investigators became more familiar with the material. Donor site thickness for the study site averaged .006' +/- .002' compared to .013' +/- .018' for control (p less than .0001) and the epidermal donor site healed an average of 4 days sooner (10 +/- 6 vs. 14 +/- 8 days) (p less than .0001). As the wounds matured during the first year, both patients and surgeons felt that both sites became more comparable in appearance and function. At the completion of the study, there was less hypertrophic scarring of the artificial dermis, and more patients preferred the artificial dermis to the control graft. Artificial dermis with an epidermal graft provides a permanent cover that is at least as satisfactory as currently available skin grafting techniques, and uses donor grafts that are thinner and donor sites that heal faster.