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Biomedical subjects

H H Steinhoff

Publications and source records attributed to H H Steinhoff.

3 recordsLinked to original sources

Cardiac afferents and the renal response to positive pressure ventilation in the dog.

The effects of cardiac denervation on renal function during spontaneous breathing (SB) and controlled mechanical ventilation (CMV) were investigated in six mongrel dogs. Selective and reversible blockade of cardiac afferents was achieved by instillation of procaine 2% into the pericardium. Application of procaine 2% into the pericardium during SB caused a statistically significant depression of urine flow (-55%), of sodium (-64%) and potassium excretion (-42%), and of inulin (-21%) and PAH-clearance (-30%). After institution of CMV with a positive end-expiratory pressure (PEEP) of 10 cm H2O a further, statistically significant decrease in urine flow (-42%) and sodium excretion (-70%) and of the inulin (-15%) and PAH-clearance (-38%) was observed. Global hemodynamics, mean arterial pressure (MAP), central venous pressure (CVP), mean pulmonary artery pressure (MPAP) and cardiac index (CI) did not change significantly after installing procaine 2% into the pericardium during SB. After institution of CMV an increase in CVP and MPAP occurred whereas MAP and CI remained unchanged. During the following periods of spontaneous breathing first with blockade of cardiac afferents and later after washing out the procaine with NaCl 0.9% all parameters of renal function approached control levels as measured in the first period of spontaneous breathing without cardiac denervation.

Animals

[Artificial respiration and kidney function disorder--a vicious circle?].

Acute lung disease is commonly associated with interstitial pulmonary edema and a tendency towards partial or total alveolar collapse. To counteract this tendency mechanical ventilation is successfully used in most cases. Mechanical ventilation, however, leads to a harmful retention of water and salt, which may worsen interstitial pulmonary edema and further impair gas exchange. This problem seems to be less known. A survey of the effects of currently used modes of mechanical ventilation on excretory function and hemodynamics of the kidneys is given together with a short review of the possible afferent and efferent mechanisms which mediate the renal response to mechanical ventilation. Some clinical suggestions are made to break through the vicious cycle between mechanical ventilation and kidney function.

Animals

Facilitation of renal function by intermittent mandatory ventilation.

The effects of intermittent mandatory ventilation (IMV) and controlled mechanical ventilation (CMV) on excretory function and the hemodynamics of the kidneys were studied in two groups of anaesthetized dogs during periods of 3 and 4 h. IMV was associated with statistically significant improved urinary output and renal plasma flow of approximately 50 and 35%, respectively. Graphical and statistical analysis revealed certain cross-over effects indicating that the beneficial effect of IMV was more pronounced if it was used following CMV. The improvements in renal function were interpreted as consequences of decreased mean intrathoracic pressures during IMV as compared to CMV. A correlation to global hemodynamic changes could not be established. IMV does facilitate kidney function and hence may successfully counteract the retention of water and salt which occurs during prolonged mechanical ventilation.

Blood Pressure