[Jet ventilation in laryngotracheal surgery]. / Die Jet-Ventilation in der operativen Laryngologie.

Conventional endotracheal intubation can be a limiting factor in endolaryngeal and endotracheal surgery. Tubeless jet ventilation can overcome this problem and provides an unlimited operation field to the surgeon. Since the development of first jet ventilation systems, many modifications have been performed and are used permanently in daily clinical routine. The aim of this work is to provide an overview of widely used jet ventilation systems and furthermore to list all advantages, as well as disadvantages of this technique in laryngotracheal surgery.

[Development of a jet tracheoscope. Value and possible uses in superimposed high frequency jet ventilation in endoscopic surgery of the respiratory tract]. / Entwicklung eines Jet-Tracheoskops. Wertigkeit und Einsatzmöglichkeiten der superponierten Hochfrequenz-Jet-Ventilation (SHFJV) in der endoskopischen Chirurgie der Atemwege.

BACKGROUND AND OBJECTIVE: Tubeless jet-ventilation offers the surgeon an unimpaired surgical field and is therefore widely used in endolaryngeal surgery. In order to permit endotracheal surgery using the same devices and instruments as those used for the larynx, we have developed special jet-tracheoscopes. Here, we report on our experience with superimposed high-frequency jet-ventilation (SHFJV) together with total intravenous anaesthesia (TIVA) in endolaryngeal and especially endotracheal surgery. PATIENTS AND METHODS: The medical reports of 172 patients (91 females, 81 males) who had undergone endolaryngeal or endotracheal surgery in SHFJV were analysed retrospectively. RESULTS: Sufficient ventilation was possible in all cases and no vitally critical situation occurred. The main indication was laryngotracheal stenosis of different origins. No significant advantages could be observed in phonosurgery. There was no difficulty in exposing the endolarynx and subglottis with the currently available laryngoscopes (five sizes). The newly developed jet-tracheoscopes (two sizes) allowed a quick and safe extension of the operating field onto the tracheal bifurcation. CONCLUSIONS: SHFJV together with TIVA enlarges the diagnostic and therapeutic options in endoscopic surgery of the respiratory tract and is in many cases the precondition for endoscopic treatment without tracheotomy. In particular, the newly developed jet-tracheoscopes widen the spectrum of endoscopic surgery and allow the use of the micromanipulator guided CO2-laser in the trachea.

Influence of a novel amino acid solution (enriched with the dipeptide glycyl-tyrosine) on plasma amino acid concentration of patients with acute renal failure.

In this randomized, double-blind controlled study we compared the effect of parenteralnutrition with two different amino acid solutions on the plasma concentration of amino acids in 27 patients with acute renal failure. Fourteen patients received the new dipeptide-containing (glycyl-tyrosine) amino acid solution (AADI) in combination with glucose (60%) and fat (10%) as an 'all-in-one' solution over 120 h continuously via a central venous catheter. In the control group (AAST), parenteral nutrition with a standard amino acid solution in isonitrogenous and isocaloric form (0.7 g amino acids/kg BW/day and 25 kcal/kg BW/day) was administered to 13 patients over the same period of time. The administration of the dipeptide-containing amino acid solution caused a return to within the normal range of most of the amino acid concentrations which were decreased at the onset. A significant difference could be found between the AADI and AAST group for the achieved plasma concentrations of threonine (P < 0.01), phenylalanine (P<0.05), isoleucine (P<0.05), tryptophan (P<0.01) and ornithine (P<0.05), The phenylalanine/tyrosine ratio, did not change in the AADI group, while a marked increase was observed in the AAST group. (152.7 +/- 23.5 - 159.8 +/- 37.6 vs 172.6 +/- 24.6 - 310.6 +/- 136.7, respectively). The plasma concentration of glycyl-tyrosine was at the limit of detectability indicating rapid hydrolysis of the dipeptide in acute renal failure. These data suggest that the new dipeptide-containing amino acid solution offers a clear advantage over a standard amino acid formulation in correcting the amino acid imbalances in plasma of patients with ARF and is able to maintain normal tyrosine concentrations and phenylalanine/tyrosine ratio.

[Special problems of nutrition therapy in patients with terminal kidney insufficiency with chronic ambulatory hemodialysis]. / Spezielle Probleme der Ernährungstherapie bei Patienten mit terminaler Niereninsuffizienz unter chronisch ambulanter Hämodialyse.

The treatment of end-stage chronic renal failure with intermittent ambulatory hemodialysis induces additional catabolic stimulus. Thus, the protein requirements of maintainance hemodialysis patients with 1.2 to 1.4 g/kg/day are higher than in the predialysis state. An energy intake of 35 to 38 kcal/kg/day contributes to an optimal anabolic utilization of incorporated protein. The catabolic response in case of complications or stress situations demands supplementation of nutrients.

[Special problems of nutritional therapy in chronic kidney insufficiency in the pre-dialysis stage]. / Spezielle Probleme der Ernährungstherapie bei chronischer Niereninsuffizienz in der Prädialysephase.

The main objectives of medical and nutritional management of patients with chronic renal failure are to slow down the progression of renal disease and to prevent secondary complications due to hypertension, uremic metabolic disturbances, and bone disease. The importance of nutritional measures for this purpose is increasingly recognized. In the setting of vitamin D and calcium deficiency secondary hyperparathyroidism and retention of phosphate result in renal osteodystrophy. An increase in dietary calcium and avoidance of foods rich in phosphate are important. In some patients supplementation of vitamin D3 may be necessary while calcium homeostasis is monitored during follow up. The dietary protein content can influence the severity of the uremic state. Normal or increased consumption of protein may accelerate the progression of renal disease due to the accumulation of nitrogenous products. In addition, uremia itself may cause loss of appetite and thus accumulation of endogenous nitrogen compounds as a result of protein catabolism. Protein restriction under such circumstances may cause malnutrition and an associated increase in morbidity and mortality. Thus, dietary management must consist of individually designed restriction of total protein intake with ingestion of high value protein. This allows balanced nitrogen metabolism with a reduction in circulating uremic toxins.

[Differential indications: parenteral-enteral nutrition in intensive care patients]. / Differentialindikationen: parenterale-enterale Ernährung beim Intensivpatienten.

The number of patients admitted to the intensive care unit because of malabsorption is remarkably high. Therefore nutritional therapy plays an important role in the management of intensive care patients. At the beginning of nutritional support the extent of deficiency and severity of nutritional disturbances as well as estimated duration of impossibility for oral alimentation have to be set up. Furthermore advantages and disadvantages of parenteral and enteral nutrition have to be considered to avoid any possible complications.