Intensive care medicine
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Intensive care medicine · Jan 1990
Comparative Study Clinical TrialOptimal oxygen delivery in critically ill patients.
Standard hemodynamic support in septic shock is to increase pulmonary capillary wedge pressure to above 15 mmHg by volume replacement and to give inotropic support if the mean arterial pressure (MAP) is not adequate. In an attempt to decrease mortality in critically ill patients, oxygen delivery (DO2) was increased by switching inotropic support from dobutamine alone or in combination with norepinephrine to dopamine alone, or by adding dopexamine, prostacyclin, or hypertonic saline to the treatment. ⋯ The results indicate that if adequate volume and inotropic support is provided for critically ill patients, the detectable oxygen debt is small and has little effect on patient outcome. When DO2 is adequate, factors other than a tissue oxygen deficit seem to determine patient outcome.
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Intensive care medicine · Jan 1990
P 0.1/PIMax: an index for assessing respiratory capacity in acute respiratory failure.
We studied airway occlusion pressure (P 0.1) and maximal inspiratory pressure (PIMax) in 10 healthy volunteers (Group A), 10 early postsurgical cardiac patients on spontaneous breathing (Group B), 10 patients mechanically ventilated for ARF (Group C), 10 patients weaning from mechanical ventilation after ARF (Group D) and 10 patients extubated after post-ARF (Group E). We calculated the index P 0.1/PIMax in an attempt to link the ventilatory demands and muscle ventilatory reserve. ⋯ When the index P 0.1/PIMax was used they were C = (90%, 100%), D = (80%, 87%) and A + B + E = (86%, 90%). We conclude that the index P 0.1/PIMax increases the reliability of P 0.1 alone to correctly classify the patients that will need either full, partial or no ventilatory support in ARF.
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Intensive care medicine · Jan 1990
Comment Letter Case ReportsRewarming by extracorporeal circulation.
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Intensive care medicine · Jan 1990
Errors in tracheal pressure recording in patients with a tracheostomy tube--a model study.
The recording of intratracheal pressure in patients breathing through a tracheostomy tube is marred by methodological problems. In model experiments it has been shown that the introduction of a recording catheter into the tracheostomy tube alters the recorded pressure by as much as 20-40%. ⋯ Pressure recordings from this part of a model trachea are compared with results obtained from a reference pressure port 100 mm below the tube ending. The results show that it is possible to record expiratory pressure with good accuracy but that inspiratory pressure is still overestimated by 9-16%.
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Intensive care medicine · Jan 1990
Measurement of extravascular lung water by thermal-dye dilution technique: mechanisms of cardiac output dependence.
The extent to which extravascular lung water (EVLW) is dependent on cardiac output was analysed in anaesthetized and mechanically ventilated pigs. EVLW was measured by thermal-dye dilution technique, by a fibreoptic thermistor catheter system (system 1), and by a thermistor catheter-external optical cuvette system (system 2). During baseline conditions, at which cardiac output was 3.65 l/min, and EVLW was 11.7 and 7.7 ml/kg b.w. with systems 1 and 2 respectively. ⋯ With system 1 the CO dependence was due to different time constants in thermistor and optical systems, and with appropriate phasing the dependence could be eliminated. With system 2 a large overestimation of the mean transit time difference between the two indicators was seen when cardiac output was low, resulting in overestimation of EVLW. It is concluded that the dependence of EVLW volume on cardiac output is an artefact due to technical problems in the design of the recording equipment rather than a reflection of pulmonary or vascular effects.