Journal of clinical monitoring and computing
-
J Clin Monit Comput · Jan 2000
ReviewAssessment and monitoring of flow limitation and other parameters from flow/volume loops.
Flow/volume (F/V) spirometry is routinely used for assessing the type and severity of lung disease. Forced vital capacity (FVC) and timed vital capacity (FEV1) provide the best estimates of airflow obstruction in patients with asthma, chronic obstructive pulmonary disease (COPD) and emphysema. Computerized spirometers are now available for early home recognition of asthma exacerbation in high risk patients with severe persistent disease, and for recognition of either infection or rejection in lung transplant patients. ⋯ Finally, the mechanism of ventilatory constraint can be identified with the use of exercise tidal volume F/V loops referenced to maximum F/V loops and static lung volumes. Patients with severe COPD show inspiratory F/V loops approaching 95% of total lung capacity, and flow limitation over the entire expiratory F/V curve during light levels of exercise. Surprisingly, patients with a history of congestive heart failure may lower lung volume towards residual volume during exercise, thereby reducing airway diameter and inducing expiratory flow limitation.
-
J Clin Monit Comput · Jan 2000
Randomized Controlled Trial Clinical TrialNeonatal monitoring after maternal fentanyl analgesia in labor.
To characterize different methods of monitoring neonatal effects associated with maternal opioid analgesia. Special focus was on the static-charge-sensitive bed (SCSB), which could potentially serve as a non-invasive neonatal monitor. ⋯ Several differences were seen between the fentanyl and the control group babies. The SCSB method proved sensitive enough to find neonatal effects of maternal analgesia. Together with ECG and SpO2 monitoring, SCSB gives plentiful information on neonatal well-being in a non-invasive way. Results of this study emphasize the importance of neonatal monitoring after maternal opiate use in labor.
-
Improving the prediction of successful ventilator weaning and extubation is a goal that all Intensivists and perioperative physicians strive for. The successful wean and extubation of ventilated patients decreases hospital length of stay and associated costs, but more importantly it also reduces patient morbidity and mortality. ⋯ We also review the non-respiratory factors affecting weaning and the role of the bedside nurse and respiratory therapist. Resolution of the pulmonary compromise and an understanding of respiratory physiology, used in conjunction with monitored indices of weaning parameters in a consistent fashion will continue to improve our success rates of ventilator weaning and extubation.
-
J Clin Monit Comput · Jan 2000
Estimation of jugular venous O2 saturation from cerebral oximetry or arterial O2 saturation during isocapnic hypoxia.
Near-infrared spectroscopy (NIRS) has the potential for providing valuable information about oxygen delivery to the brain. However, questions have been raised about the accuracy of these measurements. This study was undertaken to compare noninvasive cerebral saturation measurements to jugular venous saturation under conditions of hypoxia and hypercapnia. ⋯ Cerebral oxygen saturation measured by cerebral oximetry compares well to the measured SjvO2 in normal subjects, despite multiple physiological reasons for differences. The closer relationship of SjvO2 to rSO2 than SaO2 under the conditions of these experiments indicates that the measurement reflects primarily intracranial saturation. However, outcome studies under clinical conditions are needed to determine the clinical utility of cerebral oximetry.
-
Traditionally, the study of CO2 and O2 kinetics in the body has been mostly confined to equilibrium conditions. However, the peri-anesthesia period and the critical care arena often involve conditions of non-steady state. ⋯ The lesser known area of non-steady state O2 kinetics is introduced, including the measurement of pulmonary O2 uptake per breath. Future directions include the study of the respiratory quotient per breath, where the anaerobic threshold during anesthesia is identified by increasing respiratory quotient.