Critical care medicine
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Critical care medicine · Nov 1988
Comparative StudyUse of transthoracic bioimpedance to determine cardiac output in pediatric patients.
The use of a transthoracic bioimpedance monitor to determine cardiac output was evaluated in critically ill children. The children ranged in age from 10 months to 8 yr and their height and weight ranged from the third to the 97th percentile. Each child had a thermodilution catheter in place to monitor cardiac output. ⋯ This method of determining L was superior to using either measured thoracic length or the manufacturer's guidelines to obtain L and resulted in an excellent correlation between COTD and COBI (r = .94; p less than .05; n = 59). In children less than 125 cm in height, measured thoracic length alone was inadequate to use for L but provided a good approximation of L when multiplied by 1.25. This study suggests that the use of transthoracic bioimpedance to determine cardiac output compares favorably with thermodilution techniques and it is noninvasive.
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Critical care medicine · Nov 1988
A new infant ventilator for normal and high-frequency ventilation: influence of tracheal tube on distal airway pressure during high-frequency ventilation.
A new infant ventilator for both normal and high-frequency ventilation is described. High pressure gas delivered via a jet in the breathing limb of a T-piece, in which there are no valves, drives respiratory fresh gas (RFG), supplied to the tracheal tube from any low pressure source, into the lungs. ⋯ In this open valveless breathing system, desynchronized spontaneous and artificial ventilation occurred quietly without any marked variation in the airway pressures. This preliminary study on a new pneumatic system shows its potential for simplifying and improving infant ventilation.
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Critical care medicine · Nov 1988
Multicenter Study Clinical TrialPediatric risk of mortality (PRISM) score.
The Pediatric Risk of Mortality (PRISM) score was developed from the Physiologic Stability Index (PSI) to reduce the number of physiologic variables required for pediatric ICU (PICU) mortality risk assessment and to obtain an objective weighting of the remaining variables. Univariate and multivariate statistical techniques were applied to admission day PSI data (1,415 patients, 116 deaths) from four PICUs. ⋯ In all groups, the number and distribution of survivors and nonsurvivors in adjacent mortality risk intervals were accurately predicted: total validation group (chi 2(5) = 0.80; p greater than .95), each PICU separately (chi 2(5) range 0.83 to 7.38; all p greater than .10), operative patients (chi 2(5) = 2.03; p greater than .75), nonoperative patients (chi 2(5) = 2.80, p greater than .50), cardiovascular disease patients (chi 2(5) = 4.72; p greater than .25), respiratory disease patients (chi 2(5) = 5.82; p greater than .25), and neurologic disease patients (chi 2(5) = 7.15; p greater than .10). ROC analysis also demonstrated excellent predictor performance (area index = 0.92 +/- 0.02).
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Critical care medicine · Oct 1988
ReviewIncomplete global myocardial ischemia during cardiac arrest and resuscitation.
During cardiac arrest (no flow) and CPR (low flow), the onset of myocardial ischemia is followed by myocardial respiratory acidosis. Myocardial contractility is more decreased by respiratory than by metabolic acidosis. We demonstrated in a porcine model of cardiac arrest and in human patients increases in mixed venous PCO2 during CPR, whereas PaCO2 was decreased. ⋯ In great cardiac vein blood, even more profound respiratory acidosis with only minor decreases in bicarbonate and only moderate increases in lactate were observed. Intramyocardial pH was profoundly decreased. The severity of respiratory acidosis as a determinant of resuscitability and survival should be further investigated.
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Critical care medicine · Oct 1988
Clinical TrialPhilosophical, ethical, and legal aspects of resuscitation medicine. I. Deferred consent and justification of resuscitation research.
Informed prospective consent for clinical resuscitation research may not be possible. Deferred consent is an untenable notion. Consent to continue in research cannot be used to support a claim that there was, or would have been, consent to the initiation of research. The conditions for the justifiability of resuscitation research without informed consent are: a) patient is comatose; b) lifesaving treatment must be given immediately; c) given all available evidence, there is reason to believe that the probability of death or severe deficit with experimental or control therapy is not greater than the probability of death or severe deficit on usual therapy; d) given all available evidence, there is reason to believe that the probability of normal or near-normal outcome is greater on experimental or control therapy than on usual therapy; and e) the study can provide evidence on whether there is a significant difference between experimental and control therapies in the incidence of normal or near-normal survival.