Journal of clinical monitoring and computing
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J Clin Monit Comput · Dec 1999
The influence of left lateral position on cardiac output changes after head up tilt measured by impedance cardiography.
The value of the impedance cardiography (IC) method for measuring cardiac output (CO) with the subject in the left lateral position has not yet been established. We compared the CO after a 30 degrees head-up tilt with the subjects in the supine and left lateral position. ⋯ When using the IC method of SV measurement, the absolute value of the CI changes when moving from the supine to lateral positions. It is not clear whether this change is physiologic or an artifact of the measurement technique. However, changes in CI in response to a 30 degree head up tilt are the same in either position. We conclude that changes in CI can be measured with the IC method in the lateral position.
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J Clin Monit Comput · Dec 1999
Comparative Study Clinical TrialA comparison of pulse oximetry and near infrared spectroscopy (NIRS) in the detection of hypoxaemia occurring with pauses in nasal airflow in neonates.
The aim of this study was to compare the ability of NIRS and pulse oximetry to detect changes in cerebral oxygenation occurring in response to a pause in nasal airflow (PNA). ⋯ We conclude that both techniques are sensitive to changes in oxygenation during PNA. Small changes in cerebral Hbdiff and arterial SpO2 do not always correlate for physiological reasons. A change in Hbdiff of >0.3 micromol 100 g brain(-1) is likely to be physiologically significant and is associated with a change in SpO2 of 12%.
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J Clin Monit Comput · Dec 1999
Comparative Study Clinical TrialMonitoring of heart and respiratory rates in newborn infants using a new photoplethysmographic technique.
A new photoplethysmographic (PPG) device for respiratory and heart rate monitoring has been evaluated in the neonatal care units at the University Children's Hospital of Uppsala, Sweden. The purpose of this study was to compare this new device with more established techniques, i.e., transthoracic impedance plethysmography (TTI) for monitoring of respiratory rate and ECG for heart rate monitoring. ⋯ Electrode and motion artefacts seem to disturb the ECG signals and, particularly, the impedance signals. During periods of high quality ECG and impedance signals, the new optical device produces signals of equal quality to these traditional methods, and is in some cases even better. The new device is non-invasive and has a small optical probe. These factors indicate further advantages of the photoplethysmographic method.
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J Clin Monit Comput · Dec 1999
Comparative StudyA comparison of the Internet and the standard textbook in preparing for the professional anaesthetic examination.
The Internet is increasingly being recognised as a source of information in different fields, and medicine is no exception. We investigated the use of the Internet as an aid in preparing for the professional medical examinations. The Internet was compared to a standard textbook in answering a randomly selected past examination paper. ⋯ In contrast, the textbook provided adequate information in only 73.3% of the questions. The time required to search for information on the Internet was more than that required for a single textbook. (approximately 2 hours per question compared to 30 minutes per question respectively). However, with the rapid development of computer technology and the cyberspace, the Internet may prove to be a viable alternative or a good supplement to the standard textbook when trainee anaesthetists are preparing for their professional medical examinations.
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J Clin Monit Comput · Dec 1999
Inhaled nitric oxide fraction is influenced by both the site and the mode of administration.
Inhaled nitric oxide (NO) can be delivered continuously or sequentially (= during inspiration) at different locations of the ventilation circuit. We have tested the influence of locations, modes of NO administration and the ratio of the inspiratory time over the respiratory cycle time (I/I + E ratio) on the accuracy of NO fractions, delivered by 2 devices: Opti-NO and Flowmeter. ⋯ For the continuous NO delivery, locations above the Y piece are mandatory. However, locations below the Y piece imposes a sequential system, which can also be used for the sites located above the Y piece.