Journal of clinical monitoring and computing
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J Clin Monit Comput · Jan 2000
Atypical "tails-up" capnograph due to breach in the sampling tube of side-stream capnometer.
An atypical "tails-up" capnograph pattern was noticed in a patient during the use of an accidentally crushed sampling tube with a slit-like hole. We investigated the mechanics involved in the observed capnograph pattern. ⋯ During IPPV, pressure in the breathing circuit is lower during exhalation, thus allowing air to enter through the slit-like hole in the sampling tube causing erroneously low ETCO2 and expiratory sevoflurane. With inspiration, positive pressure in the breathing circuit, transmitted to the sampling tube, prevents air admixture and the upsurge in CO2 is displayed giving the capnograph an atypical "tails-up" appearance. During spontaneous breathing, since pressure in the breathing circuit barely becomes positive during exhalation and is negative during inspiration, air mixes with the sampled gas during both phases and so the capnograph shape was normal but with lower values for ETCO2, insp./exp. sevoflurane, and nitrous oxide levels. If undiagnosed, this defect in the sampling tube can lead to significant errors in the measurement of inspired and expired gas concentrations.
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Inhaled nitric oxide is a ubiquitous molecule which is produced endogenously and is also found in air pollution and in cigarette smoke. After describing the chemistry of NO, we review its history from the first description in 1980 to the current clinical indications. ⋯ Possible drug interactions are listed. Inhaled nitric oxide is here to stay, and future studies will provide more information on its therapeutic dose, duration and potential toxicity.
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J Clin Monit Comput · Jan 2000
Warning devices for prevention of dental injury during laryngoscopy. Preliminary report.
The prototypes of two novel warning devices for protection against dental trauma during direct laryngoscopy are described. Either can be attached to a standard laryngoscope blade (e.g., Macintosh). The basic design is that of a switch that is closed by pressure on the maxillary incisors by the laryngoscope blade.
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J Clin Monit Comput · Jan 2000
An IBM PC-based system for the assessment of cardio-respiratory function using oscillating inert gas forcing signals.
An IBM PC-based real-time data acquisition, monitoring and analysis system was developed for the assessment of cardio-respiratory function, i.e. airway dead space, alveolar volume and pulmonary blood flow, using oscillating inert inspired gas forcing signals. ⋯ A system was developed to deliver, monitor and analyse on-line, and in real-time, output data from the sinusoid forcing technique. The technique was administered using the system in various subjects, and produced favourable predictions.