Critical care medicine
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Critical care medicine · Jan 1997
Influence of airway pressure on minimum occlusive endotracheal tube cuff pressure.
To examine the in vivo relationship between peak inflation pressure and the minimum occlusive pressure of a "high-volume, low-pressure" endotracheal tube cuff that may in some circumstances promote tracheal ischemic complications. ⋯ Knowledge of the linear relationship between peak inflation pressure and minimum occlusive pressure can help the clinician identify patients who may be at risk for cuff-induced tracheal ischemic complications, such as tracheoesophageal fistula and tracheal stenosis. In our series, a cuff pressure of 25 mm Hg corresponded to a peak inflation pressure of 35.3 mm Hg (48 cm H2O). Patients with higher peak inflation pressures may be at risk for ischemic tracheal injury, despite proper cuff inflation techniques.
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Critical care medicine · Jan 1997
Variability of indices of hypoxemia in adult respiratory distress syndrome.
To determine the usefulness of indices of hypoxemia in assessing patients with the adult respiratory distress syndrome (ARDS). ⋯ All indices of hypoxemia are affected by changes in FIO2 in patients with ARDS. PaO2/FIO2 ratio exhibits the most stability at FIO2 values of > or = 0.5 and PaO2 values of < or = 100 torr (< or = 13.3 kPa), and is a useful estimation of the degree of gas exchange abnormality under usual clinical conditions. Venous admixture varies substantially with alteration of FIO2 in patients who have clinically important ventilation/perfusion abnormalities. Under these circumstances, venous admixture is a poor indicator of the efficiency of pulmonary oxygen exchange, even if venous admixture is calculated from measured arterial and venous oxygen content values. Estimated venous admixture, based on an assumed arterial-venous oxygen content difference, is even more unreliable.
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Critical care medicine · Jan 1997
Quality of life after cardiac surgery complicated by multiple organ failure.
To evaluate quality of life after prolonged multiple system intensive care treatment in cardiac surgical patients. ⋯ Patients treated with prolonged multiple system intensive care after heart surgery have a poor outcome with respect to quality of life measured at least 1 yr after discharge from the ICU.
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Critical care medicine · Jan 1997
Tracheal gas insufflation during pressure-control ventilation: effect of using a pressure relief valve.
Pressure-control ventilation minimizes alveolar overdistention by limiting peak airway pressure, but a consequence of this pressure limitation may be a reduction in tidal volume with subsequent hypercarbia. Tracheal gas insufflation (TGI) can be used in combination with pressure-control ventilation to augment CO2 elimination. During pressure-control ventilation with continuous TGI, we observed that peak airway pressure increased above the set inspiratory pressure. Based on this observation, we investigated the ability of the pressure-control ventilator circuit to compensate for continuous TGI and the effect of insertion of a pressure relief valve to eliminate over-pressurization. ⋯ A pressure relief valve is a necessary adjunct to maintain peak airway pressure at set inspiratory pressure and keep total inspiratory tidal volume constant when continuous TGI is administered in conjunction with pressure-control ventilation.