American journal of critical care : an official publication, American Association of Critical-Care Nurses
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To examine the effect of abnormal cardiac index on the accuracy of measurement of oxygen saturation by pulse oximetry. ⋯ In patients with abnormal cardiac index, the pulse oximeter measurements exceeded the actual oxygen saturation by up to 7%. Pending prospective studies, clinicians should be aware that when certain cardiopulmonary parameters are abnormal, the margin of error in measurements of oxygen saturation obtained with a pulse oximeter may be greater than when those parameters are normal.
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Comparative Study
12-lead ST-segment monitoring vs single-lead maximum ST-segment monitoring for detecting ongoing ischemia in patients with unstable coronary syndromes.
12-lead ECG monitoring of the ST segment is more sensitive than patients' symptoms for detecting ischemia after thrombolytic therapy or catheter-based interventions, but it is unclear whether monitoring of the single lead showing maximum ST deviation would be as efficacious. ⋯ Monitoring of all 12 ECG leads for changes in the ST segment is necessary to detect ongoing ischemia in patients with unstable coronary syndromes.
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Comparative Study
Opioid withdrawal in neonates after continuous infusions of morphine or fentanyl during extracorporeal membrane oxygenation.
Complications of opioid analgesia include tolerance and withdrawal. ⋯ Morphine may offer marked advantages over fentanyl for providing continuous analgesia and sedation in neonates.
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Comparative Study
Comparison of 2 methods of measuring the QT interval.
Prolonged cardiac repolarization is associated with ventricular tachycardia and sudden cardiac death. Repolarization, represented by the QT interval, is usually measured on a 12-lead ECG recording. Measurements of the interval on bedside monitor ECG recordings have not been compared quantitatively with measurements on 12-lead ECG recordings. ⋯ Recordings from leads I or II on the bedside ECG monitor should be used to measure the QT interval. Once prolonged QT values are detected, recordings obtained with a 12-lead ECG can be used to confirm the analysis.
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Nursing care of patients with advanced heart failure with low ejection fraction requires strict management of IV fluids. Measurement of mixed venous oxygen saturation offers advantages over measurement of cardiac output because no administration of fluid is required and data are obtained continuously. ⋯ Similar correlations in the groups receiving and not receiving vasoactive medications suggest that even with pharmacological support, changes in mixed venous oxygen saturation may not be reflected by concomitant changes in cardiac output. Measurement of mixed venous oxygen saturation should not replace measurement of cardiac output for clinical decision making in patients with advanced heart failure with low ejection fraction.