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Effects of PEEP on extra vascular lung water and central blood volume in the dog
Author(s) -
Frostell C.,
Blomqvist H.,
Wickerts C.J.
Publication year - 1987
Publication title -
acta anaesthesiologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.738
H-Index - 107
eISSN - 1399-6576
pISSN - 0001-5172
DOI - 10.1111/j.1399-6576.1987.tb02650.x
Subject(s) - medicine , anesthesia , supine position , positive end expiratory pressure , cardiac output , blood volume , indicator dilution , fissipedia , cardiology , hemodynamics , mechanical ventilation
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. Seven dogs ventilated with a positive end‐expiratory pressure (PEEP) of 1.0 kPa (10 cmH 2 O) for a short period of time (< 20 min) displayed no significant change in EVLW as measured with the indicator dilution technique (= EVLW i ), while reductions were seen in both CBV (15%, P <0.01) and cardiac output (CO‐thermodilution technique) (10%, P <0.05). Another seven dogs ventilated with a PEEP of 1.0 kPa for 8 h showed a gradual increase in EVLW i . After 8 h, a mean increase of 34% ( P <0.01) was recorded, and the increase was also verified by post‐mortem gravimetric determination of EVLW (= EVLW g ), displaying an increase of 61% ( P <0.01). In five dogs ventilated with zero end‐expiratory pressure (ZEEP) for 8 h, no changes in EVLW i , CO, and CBV were observed, and EVLW g was mean 4.39 g/kg body weight (BW). Five additional dogs were sacrificed after 15 min of anaesthesia without catheterization and EVLW g was found to be 4.24 g/kg BW. It is concluded that EVLW i does not change measurably during ZEEP or short periods of PEEP. However, long periods (8 h) of PEEP result in elevated EVLW i values. Gravimetry supports these conclusions. Although PEEP recruits lung volume after lung damage and in this way enhances gas exchange, it appears that prolonged ventilation with PEEP also causes a significant increase of extravascular lung water in otherwise healthy lung tissue.