British journal of anaesthesia
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We studied 60 children undergoing neurosurgical procedures in the sitting position. Routine monitoring included ECG, pulse oximetry, invasive arterial pressure, in particular mean arterial pressure (MAP), and right atrial pressure (RAP). Children were allocated to two groups. ⋯ Inflation of the MAST suit induced a dramatic increase in RAP and JBVP, reinforced by addition of PEEP. There was a strong positive relationship between RAP and JBVP. There were no deleterious side effects or differences between the two groups in peroperative blood product requirements or surgical general conditions.(ABSTRACT TRUNCATED AT 250 WORDS)
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We have studied in 12 healthy male volunteers the effects of three different body positions (10 degrees head-down tilt, horizontal supine and supine with 50-cm leg elevation from the hip) on the spectral components of heart rate and finger plethysmographic amplitude variability. We have demonstrated the absence of any statistically significant difference in any measure of variability in the time of frequency domain for both of these measures between the three positions. We conclude that neither leg elevation nor 10 degrees head-down tilt is associated with any significant alteration in the dominant parasympathetic cardiac control in comparison with the resting supine position.
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We have compared arterial pressures measured by an indwelling radial cannula with those obtained non-invasively by the Finapres 2000 (Ohmeda) during spinal anaesthesia for lower segment Caesarean section. The digital outputs of both pressures were recorded using a computerized system. We studied 20 patients, yielding a total of 18,772 data points after elimination of data recorded during arterial flushing and erroneous results from each source. ⋯ Some patients and some periods of readings reflected a high degree of precision and little bias. However, unexplained large differences in pressure and trends of change that were out of phase over time occurred frequently. We conclude that the Finapres cannot be recommended as a monitor of arterial pressure in this group of patients in whom sudden hypotension may be a threat to maternal or fetal outcome.
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We describe a miniature electrochemically driven, wrist-worn infusion pump. Generation of gas by an electrolytic reaction compresses a reservoir containing medication and provides a predictable and controllable infusion rate. ⋯ This portable system, using a novel motive force, has advantages of convenience over larger systems and has sophisticated features not present in existing small systems. It has potential as a routine PCA device and it may have uses in other situations requiring convenient infusion or intermittent injection in an ambulatory setting.