Chest
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Randomized Controlled Trial Clinical Trial
Calcium inhibits the cardiac stimulating properties of dobutamine but not of amrinone.
To contrast the effect of increasing blood calcium concentrations on the cardiovascular actions of intravenous beta-adrenergic agonists and phosphodiesterase inhibitors, 46 patients recovering from aortocoronary bypass surgery received either dobutamine or amrinone both in the presence and absence of a calcium infusion. Cardiac output, systemic arterial pressure, pulmonary arterial pressure, central venous pressure, pulmonary artery occlusion pressure, heart rate, and blood ionized calcium concentration were measured before and during infusions of dobutamine (2.5 and 5.0 micrograms/kg/min) and amrinone (0.75 mg/kg bolus + 10 micrograms/kg/min or 2.25 mg/kg bolus + 20 micrograms/kg/min). After the initial dobutamine infusion period, patients were randomly and blindly assigned to receive either a calcium or placebo infusion, and the dobutamine infusions were repeated. ⋯ Calcium infusion increased arterial pressure (8 to 13 percent) but had no significant effects on any other hemodynamic parameters. Calcium reduced the increase in cardiac output produced by dobutamine by 30 percent, but it did not alter the cardiotonic actions of amrinone. Thus, calcium inhibits the cardiotonic actions of certain beta-adrenergic agonists, most likely by interfering with signal transduction through the beta-adrenergic receptor complex.
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Randomized Controlled Trial Comparative Study Clinical Trial
Positive end-expiratory pressure vs T-piece. Extubation after mechanical ventilation.
Because T-piece breathing may impair oxygenation, the best airway pressure from which to extubate ventilated patients is controversial. We compared the effects of extubation after 1 h of either CPAP 5 and T-piece/ZEEP. Once weaned from mechanical ventilation and breathing spontaneously, 106 patients were randomized to 1 h CPAP or 1 h T-piece/ZEEP, following which patients were extubated and mask O2 administered. ⋯ Nineteen T-piece patients showed improved P(A-a)O2 at 120 min compared with only ten CPAP patients. Three CPAP and two T-piece patients subsequently required reintubation. This study demonstrates that use of a T-piece dose not impair arterial oxygenation and may in fact be superior to direct extubation from CPAP 5.
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Randomized Controlled Trial Comparative Study Clinical Trial
Fluid balance during pulmonary edema. Is fluid gain a marker or a cause of poor outcome?
To evaluate the importance of fluid balance and changes in extravascular lung water (EVLW) on survival in the ICU and short-term outcome in patients with pulmonary edema. ⋯ These data support the concept that positive fluid balance per se is at least partially responsible for poor outcome in patients with pulmonary edema and defend the strategy of attempting to achieve a negative fluid balance if tolerated hemodynamically.
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Randomized Controlled Trial Clinical Trial
Heat and moisture exchanger vs heated humidifier during long-term mechanical ventilation. A prospective randomized study.
Adequate humidification of inspired gases with HMEs during long-term MV remains controversial. In this study, a comparison is made between tracheal secretions during long-term MV either with HME or conventional HH. Both the HME and HH groups were similar with respect to age, sex, diagnosis, duration of MV, SAPS and mortality. ⋯ Four and two tube occlusions occurred in HME and HH groups, respectively. Tracheal bacterial colonization was similar in the two groups. Given the advantages of HME (reduced nurses' work and financial cost), HME could be routinely used under cautious surveillance and replaced by HH if difficulty in suctioning occurs.
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Review Randomized Controlled Trial Clinical Trial
Continuous lateral rotational therapy and nosocomial pneumonia.
The adverse effects of prolonged immobility are due primarily to gravitational effects on blood flow and ventilation, impairment of the normal mucociliary escalator and possibly an increase in extravascular lung water. However, CLRT theoretically should reverse these abnormalities. The sequence of events that culminate in LRTI or pneumonia is unclear; however, low tidal volumes, increased extravascular lung water and the accumulation of bronchopulmonary secretions may lead to atelectasis, a well-known precursor of pneumonia. ⋯ The prevention of pneumonia and more rapid transfer from the ICU should offset the additional expense of a specialized bed. The data suggest that a multicenter study with accrual of a large number of patients to evaluate this form of therapy in a prospective, randomized study is necessary. If the hypothesis that CLRT decreases the incidence of nosocomial pneumonia in the ICU is proven, the impact on critical care in the 90s would be substantial.