Am. J. Respir. Crit. Care Med., Vol 154, No. 6, Dec 1996, 1653-1657.
Assessment of gastric mucosal perfusion during simulated hypovolemia in healthy volunteers
J Duranteau, P Sitbon, E Vicaut, A Descorps-Declere, B Vigue and K Samii
Departement d'Anesthesie-Reanimation, Hopital de Bicetre Le Kremlin- Bicetre, France.
We described here an original device for laser Doppler (LD) flowmetry
measurements of gastric mucosal perfusion, which was used here in healthy
volunteers. A modified nasogastric tube containing the LD probe was
inserted. Aspiration via a catheter, fixed in parallel to the probe, held
the probe against the gastric wall. This new device was used to assess
gastric mucosal perfusion in seven volunteers during simulated hypovolemia
induced by lower body negative pressure (LBNP) application. The LBNP
consisted of three successive levels of depression (-10, -20, and -30 mm
Hg). Although mean arterial pressure remained unchanged during negative
pressure application, there was a significant decrease in cardiac output
(transthoracic electrical impedance) at each stage of LBNP. In contrast,
gastric mucosal perfusion decreased significantly only at higher level of
sympathetic stimulation corresponding to unloading of both cardiopulmonary
and arterial baroreflexes (-30 mm Hg). It may be hypothetized that local
vascular mechanisms exist to maintain gastric mucosal perfusion during
moderate sympathetic stimulation induced by selective unloading of
cardiopulmonary receptors. In the healthy volunteers studied, we found that
LD flowmetry is a valuable tool to evaluate gastric mucosal perfusion when
the probe is maintained in a constant position by the technique described
here.
