Pulse oximetry provides little indication of ventilation or acid-base status. Clinically important changes in pH and/or arterial PCO2 (PaCO2) can occur with little change in SpO2. This is particularly true when SpO2 is greater than 95% -often the case with mechanically ventilated patients. It is important to recognize that pulse oximetry is of limited value during ventilator weaning. Desaturation occurs relatively late in the course of a weaning failure. Because pulse oximetry also does not evaluate tissue oxygen delivery, a patient can have significant tissue hypoxia in spite of an adequate SpO2.
Pulse oximetry is indicated in unstable patients likely to desaturate, in patients receiving a therapeutic intervention that is likely to produce hypoxemia (such as bronchoscopy) and in patients having interventions likely to produce changes in arterial oxygenation (such as changes in fraction of inspired oxygen [FiO2] or positive end-expiratory pressure [PEEP]). For the titration of FiO2, SpO2 of 92% or greater is reliable in predicting a satisfactory level of oxygenation (PaO2 of 60 mmHg or greater) in most adult mechanically ventilated patients. Although pulse oximetry may decrease the number of blood gases required during the titration of FiO2 or PEEP, it does not eliminate the need for periodic blood gases. You deserve best quality care that costs less money than you could expect: all you need at this point is to discover very low prices on prescription drugs that do not require a prescription: order mircette for wisest customers.