Critical care medicine
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Critical care medicine · Sep 1994
Multicenter StudyMortality probability models for patients in the intensive care unit for 48 or 72 hours: a prospective, multicenter study.
To develop models in the Mortality Probability Model (MPM II) system to estimate the probability of hospital mortality at 48 and 72 hrs in the intensive care unit (ICU), and to test whether the 24-hr Mortality Probability Model (MPM24), developed for use at 24 hrs in the ICU, can be used on a daily basis beyond 24 hrs. ⋯ Models developed for use among ICU patients at one time period are not transferable without modification to other time periods. The MPM48 and MPM72 calibrated well to their respective time periods, and they are intended for use at specific points in time. The increasing constant terms and associated increase in the probability of hospital mortality exemplify a common clinical adage that if a patient's clinical profile stays the same, he or she is actually getting worse.
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Critical care medicine · Sep 1994
Multicenter StudyDaily prognostic estimates for critically ill adults in intensive care units: results from a prospective, multicenter, inception cohort analysis.
To develop daily prognostic estimates for individual patients treated in adult intensive care units (ICU). ⋯ Equations using initial and repeated physiologic measurements provide a high degree of explanatory power for subsequent hospital mortality rate. These daily prognostic estimates deserve evaluation for their potential role in improving the process and outcome from clinical decision-making.
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Critical care medicine · Sep 1994
Comparative Study Clinical TrialDemand-flow airway pressure release ventilation as a partial ventilatory support mode: comparison with synchronized intermittent mandatory ventilation and pressure support ventilation.
To evaluate airway pressure release ventilation as a partial ventilatory support mode by comparing a demand-flow airway pressure release ventilation system with synchronized intermittent mandatory ventilation and pressure support ventilation. ⋯ We conclude that for patients who do not have chronic obstructive pulmonary disease, demand-flow airway pressure release ventilation can provide effective partial ventilatory support with lower peak airway pressure when compared with pressure support ventilation and synchronized intermittent mandatory ventilation. However, this airway pressure release ventilation system may be less comfortable than the other two modes, and asynchrony may occur in some patients.
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Critical care medicine · Sep 1994
Multicenter StudyA method for assessing the clinical performance and cost-effectiveness of intensive care units: a multicenter inception cohort study.
To present an approach for assessing intensive care unit (ICU) performance which takes into account both economic and clinical performance while adjusting for severity of illness. To present a graphic display which permits comparisons among a group of hospitals. ⋯ Cross-indexing of clinical and economic ICU performance is easy to calculate. It has potential as a research and evaluation tool used by physicians, hospital administrators, payers, and others.
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Critical care medicine · Sep 1994
ReviewUnderstanding the pressure cost of ventilation: why does high-frequency ventilation work?
To understand when the use of high-frequency ventilation would be advantageous, we formulated the problem of achieving adequate alveolar ventilation at minimal pressure cost by dividing it into two simpler problems: a) the pressure cost per unit of convective oscillatory flow; and b) the convective flow cost necessary to achieve a unit of alveolar ventilation. ⋯ This analysis illustrates the importance of using high-frequency ventilation in infant respiratory distress syndrome and of optimizing the amount of PEEP. It also points out the danger of barotrauma in the derecruited lung. When the lungs are in a derecruited state, the combinations of frequency, PEEP, and tidal volume that yield adequate ventilation with safe distention of recruited alveoli are severely limited.