Medical principles and practice : international journal of the Kuwait University, Health Science Centre
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Clinical Trial
The relationship between end tidal carbon dioxide and arterial carbon dioxide during controlled hypotensive anaesthesia.
To prospectively assess the magnitude of changes in the arterial-to-end tidal carbon dioxide gradient [P(a-ET)CO2] as well as in the ratio of physiological dead space to tidal volume (Vdphys/Vt) during controlled hypotensive anaesthesia, and to evaluate whether or not ventilatory requirements remain unaltered during this procedure. ⋯ The decrease in ETCO2 does not reflect the changes in PaCO2. The larger decrease in ETCO2 is mainly due to the increase in the Vdphys/Vt ratio. During anaesthesia, once normocapnia is achieved with normal arterial blood pressure, there is hardly any need to change the ventilation after initiation of controlled hypotension.