Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Nov 1987
Computerized tomography of the chest and gas exchange measurements during ketamine anaesthesia.
The effects of atelectasis on pulmonary gas exchange were studied in eight supine, clinically lung-healthy patients. Atelectasis was studied by computerized tomography (CT), and gas exchange by blood gas analysis. The distribution of ventilation/perfusion ratios was assessed by a multiple inert gas elimination technique. ⋯ After muscular relaxation and commencement of mechanical ventilation, all patients but one developed both shunt (2-6% of cardiac output) and atelectasis. The shunt correlated to the size of atelectasis. It is concluded that the occurrence of shunt during anaesthesia is related to the development of atelectasis in dependent lung region, which is consistent with the hypothesis that it is changes in chest-wall mechanics that cause atelectasis.
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Acta Anaesthesiol Scand · Nov 1987
Effects of PEEP on extravascular lung water and central blood volume in the dog.
Twenty-four mongrel dogs were anaesthetized and ventilated mechanically in the supine position. Extravascular lung water (EVLW) and central blood volume (CBV) were measured with a double indicator (dye/cold) dilution technique. Both indicators were detected intravascularly in the aortic root with a fibreoptic thermistor catheter. ⋯ It is concluded that EVLWi does not change measurably during ZEEP or short periods of PEEP. However, long periods (8 h) of PEEP result in elevated EVLWi values. Gravimetry supports these conclusions.(ABSTRACT TRUNCATED AT 250 WORDS)