Critical care medicine
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Critical care medicine · May 1992
ReviewSelective decontamination of the digestive tract in the intensive care unit: current status and future prospects.
To evaluate the available data on selective decontamination of the digestive tract. This therapy aims to prevent infection in critically ill patients admitted to ICUs. Microbial carriage in the oropharynx, stomach, and gut; infection; mortality rate; and antibiotic resistance are the outcome events that are being reviewed. ⋯ There is a general consensus about the efficacy of selective decontamination in diminishing microbial carriage and acquired infection rates, although conclusions about benefits related to mortality rates vary. Differences in mortality rate are found in the selective decontamination studies of patients with curable diseases, including multitrauma and cardiovascular patients. More data on resistance, collected over a longer period of time, are needed. Practical problems of blinding and the major ecological effect of selective decontamination may explain the lack of a randomized, placebo-controlled, double-blind trial.
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Critical care medicine · May 1992
Process of forgoing life-sustaining treatment in a university hospital: an empirical study.
The difficult decision to forgo (withhold or withdraw) life-sustaining treatment has received extensive commentary. Little attention has been paid to how physicians do, and should, care for dying patients once this decision is made. This study describes the characteristics of patients who forgo treatment, determines the range and sequential process of forgoing treatment, and suggests ethical and public policy implications. ⋯ Forgoing life-sustaining treatment is not a single decision but it often occurs in a sequential manner over several days. A strict analysis of the benefits and burdens of various interventions may be inadequate in deciding what interventions are appropriate in the care of the dying patient.
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Critical care medicine · May 1992
A simple method for the measurement of intrinsic positive end-expiratory pressure during controlled and assisted modes of mechanical ventilation.
To evaluate a new and simple method for the measurement of intrinsic positive end-expiratory pressure during controlled and assisted modes of mechanical ventilation. ⋯ The manual valve method can be used to determine intrinsic positive end-expiratory pressure during controlled and assisted modes of ventilatory support with current ventilators. The availability of such an approach should facilitate the routine monitoring of intrinsic positive end-expiratory pressure in mechanically ventilated patients, thereby aiding clinical decision-making and management in these critically ill individuals.
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Critical care medicine · May 1992
Dobutamine pharmacokinetics and pharmacodynamics in pediatric intensive care patients.
To evaluate the pharmacokinetics and pharmacodynamics of dobutamine in critically ill children. ⋯ There was no effect of plasma dobutamine concentration or infusion rate on plasma clearance rate. For this group of patients, over the range of the intravenous doses studied, dobutamine pharmacokinetics followed a first-order kinetic model. Threshold values for dobutamine usually show increases in cardiac output before changes in heart rate. These data demonstrate that dobutamine is an effective inotropic agent in critically ill pediatric patients and has minimal chronotropic action.
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Critical care medicine · May 1992
Validation of bedside measurements of absolute human renal blood flow by a continuous thermodilution technique.
There is a clinical need for a system that would allow rapid assessment of renal blood flow in patients with oliguric circulatory shock. A local, continuous thermodilution technique for the measurement of renal venous blood flow, using readily available equipment, was developed. To test the hypothesis that this system would allow measurement of renal blood flow in clinical situations, we compared simultaneous measurements made by the continuous thermodilution technique with measurements of: a) absolute flow measured by volumetric collection in an in vitro flow model; b) renal arterial blood flow measured by electromagnetic flow probe under changing hemodynamic conditions in nine pigs; and c) calculated renal blood flow derived from a clearance technique in 16 patients after cardiac catheterization. The technique utilizes a short-duration, constant infusion of room temperature normal saline into the renal vein via a retrograde thermodilution catheter, with measurement of flow at a thermistor 1 cm back from the tip of the catheter. ⋯ This technique is simple to use, requires only venous cannulation and injection of normal saline, and allows rapidly repeatable, immediately available measurements of renal blood flow in a wide range of clinical circumstances, including severe renal impairment or anuria.