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W Heinrichs

Publications and source records attributed to W Heinrichs.

69 records · Page 4Linked to original sources
PubMed1987

[Metabolic models for the interpretation of indirect caloric measurements in intensive care patients].

Precondition for the evaluation of indirect calorimetry data by standard procedures is an undisturbed physiological metabolic situation. Metabolic changes in stress metabolism, which are a reduction of enzyme activity, increased rates of gluconeogenesis und ketogenesis, and simultaneous occurrence of lipolysis and lipogenesis cannot be considered by those calculations. Various problems concerning the evaluation of data obtained on traumatized patients confirm the presumption that standard procedures are not suitable in the case of posttraumatic metabolic disturbances. Therefore, we developed two computer-supported metabolic models, which assume a reduced activity of the three key enzymes: pyruvate dehydrogenase (PDH), phosphofructokinase (PFK) and citrate synthetase (CS). The blocked metabolites are bypassed to gluconeogenesis, lipogenesis and in so called 'pools' ('glucose-pool', 'acetyl-pool'). In addition, a detailed simulation of amino acid degradation is permitted. The models were applied to evaluate indirect calorimetric data of four patients, which could not be evaluated by standard procedures. It was shown that an evaluation of all data was possible by at least one model. All enzymes presented a slight to complete blockade. The calculated maximal activities of PFK was 1.59 mol/d, of PDH 6.31 mol/d and that of CS 6.55 mol/d. These activities were far below the values of normal human beings. As a result of these enzyme inhibitions, high rates of gluconeogenesis (max. 387 g/d) and lipogenesis (max. 511 g/d) as well as high values for the glucose-pool (max. 387 g/d) and the acetyl-pool (max. 641 g/d) were calculated. The interpretation of the pools was difficult. Renal elimination of the metabolites was not found in our patients, an accumulation was impossible for osmotic reasons. Therefore, despite the catabolic hormonal character of stress metabolism, storage as molecules of high molecular weight should be taken into account.

Calorimetry↗
PubMed1987

[Effect of L-lysine-induced amino acid imbalance on nitrogen balance in patients treated by total parenteral nutrition].

Cumulative nitrogen balances of 109 patients in 3 groups under total parenteral nutrition were studied with regard to their daily intake of l-lysin. Patients in group 1 who received a mean daily amount of 4.5 g l-lysin exclusively from the amino-acid solution showed a cumulative nitrogen balance of -51.9 g N 10 days into the study. Patients in groups 2 and 3 received, additionally, l-lysin HCl for prophylaxis or therapy of metabolic alkalosis. Thus patients in group 2 received 5.3 g l-lysin (nitrogen balance -101.4 g N/10 days) and in group 3, 8.5 g l-lysin (nitrogen balance -97.6 g N/10 days). The markedly higher negative nitrogen balance in these groups is interpreted as the effect of an amino acid imbalance due to inadequate l-lysin intake; therefore, l-lysin should no longer be used for treatment of metabolic alkalosis in patients under total parenteral nutrition.

Alkalosis↗
PubMed1987

[Critical evaluation of changes in circulating blood volume, hematocrit, hemoglobin and plasma protein concentration for the calculation of normotonic fluid losses].

Normotonic fluid losses always lead to intravascular hypovolemia and subsequently to hypovolemic shock. Unfortunately, there are no diagnostic methods sufficient to calculate the extent of normotonic losses for fluid therapy. Therefore, indirect parameters such as changes in hemoglobin concentration, hematocrit, or plasma protein concentration are usually used for monitoring fluid therapy. This paper presents the results of our study in ten healthy volunteers. We investigated whether changes in circulating blood volume or hematocrit, hemoglobin, and plasma protein concentration indicate the amount of normotonic fluid loss in dehydrated humans. Normotonic fluid losses were induced using furosemide in repeated doses of 20 mg. Control measurements were carried out before furosemide administration (ZDM1 = time of sample taken) and after 2000 (ZDM2) and 3000 ml urinary output (ZDM3). We measured hematocrit as well as concentrations of hemoglobin, plasma protein, sodium, potassium, and chloride using standard laboratory methods. Hematocrit values were corrected for trapped plasma (3%) and the body/venous hematocrit ratio (0.91). Circulating blood volume was measured using J-131 RIHSA and the "volemetron" introduced by Williams and Fine. Plasma volume and plasma water volume were calculated. After checking the data for normal distribution, statistics were calculated using the paired t test (P less than 0.01). The results are listed in Table 2. We calculated normotonic fluid losses on the basis of plasma and urinary sodium concentrations and found them to be 1720 +/- 155 ml (ZDM2) and 2392 +/- 262 ml (ZDM3).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

[A new CPAP system].

The "AMBU-CPAP system" is a new, simple and reliable circuit for administering positive airway pressure in spontaneous-breathing therapy. Some disadvantages of other CPAP devices are avoided, and the use of the system with low gas flow is possible. The change of airway pressure during respiration was measured and was found to be less than 5 millibars.

Airway Resistance↗
PubMed1980

[Disposable needles for epidural anaesthesia - basic requirements (author's transl)].

Disposable needles for epidural single-shot and catheter techniques are being marketed increasingly by different firms. As a result of our experience, the basic requirements of each of the component parts in the needle assembly are outlined. It is clear that the materials used to date are failing in some requirements and we assume that the manufactures have possibly not taken account of the suggestions of practicing anaesthesists.

Anesthesia, Epidural↗
PubMed1979

[A newly developed ventilator driven by a microprocessor (author's transl)].

The A4/6 is a newly developed ventilator, which may be used in the operating theatre or in the intensive care unit. The machine is electronically driven (microprocessor) and is characterised by a highly sensitive triggering mechanism. It is designed for the ventilation of the newborn (including premature infants) and children up to approximately 5 years. The significant and important features of its control design including its triggering mechanism will be described.

Child, Preschool↗
PubMed1978

[Investigation of gait of patients with idiopathic scoliosis and the influence of the Milwaukee brace on gait (author's transl)].

We investigated 42 juvenile patients with idiopathic scoliosist, 37 of them were provided with a Milwaukee brace and treated physically. The electromyographic activity of the musculi erectores trunci and the musculi glutaei medii were recorded during walking and standing on one leg. Simultaneously the motions of the trunc and the pelvis in the frontal plane were registered and calculated. Results without the brace: During walking the activity of the erectors trunci predominates on the convex side of the curvature of the spine. This applies as to the functional curve. The M. glutaeus medius shows an increased activity on the contralateral side of the overhang of the trunc. The priodical shifts of the trunc to the right and to the left during walking decrease with increasing activity of the M. glutaeus medius. In this way, we show the stabilizing influence of this muscle upon the statics of the spine. This should be especially considered with regard to the physical treatment of the patients. Results with the brace put on: There is only little influence of the brace upon the electrical activity of the musculi erectores trunci: we could not detect any activating ore inactivating effect of the brace. The amplitude of the periodical shifts of the trunc and the perlvis during walking is reduced by the brace. At the same time we found a greater activity of the musculi glutaei medii than with the brace taken off. We suppose that the reduced shifts of the trunc and the pelvis involved by the brace force a greater activity of the glutaeus medius.

Adolescent↗
PubMedDate not supplied

Assessment of pulmonary mechanics and gastric inflation pressure during mask ventilation.

INTRODUCTION: Mask ventilation is a procedure routinely used in emergency medicine. Potential hazards are inadequate alveolar ventilation and inflation of the stomach with air, leading to subsequent regurgitation and aspiration. The aim of this study was to measure lung function and gastric inflation pressures during mask ventilation. METHODS: For this purpose, 31 patients scheduled for routine urological procedures were studied during induction of anesthesia. Lung function was assessed by recording respiratory flow and pressure directly at the face mask. Gastric inflation was observed with a microphone taped to the epigastric area. RESULTS: Gastric inflation occurred in 22 of the 31 patients. Mean gastric inflation pressure was 27.5 +/- 6.55 cm H2O, mean compliance was 67 +/- 24.1 ml/cm H2O, mean resistance was 17.4 +/- 6.41 cm H2O/L/sec, and the mean respiratory time constant was 1.1 +/- 0.26 seconds. CONCLUSIONS: These data suggest that inspiratory pressure be limited to 20 cm H2O, and that an inspiratory time of at least four times the respiratory time constant be allowed. Monitoring airway pressure and gastric inflation is a simple technique that may improve the safe-ty of patients during mask ventilation.

Adult↗