Effects of tidal volume reduction in acute respiratory distress syndrome on gastric mucosal perfusion.
OBJECTIVE
This study was conducted with the aim of testing the effects of a reduction in tidal volume (V(T)) on gastric mucosal perfusion using laser-Doppler flowmetry in patients with acute respiratory distress syndrome (ARDS).


METHODS
It was designed as a prospective study.


METHODS
Seventeen patients with ARDS were enrolled in the study. All patients were mechanically ventilated in volume-controlled mode. Before the start of the protocol, V(T) was set at 9 ml/kg body weight.


METHODS
V(T) was reduced to 6 ml/kg body weight.


RESULTS
Measurements of systemic hemodynamic parameters and gastric mucosal blood flow (GMBF) were obtained before and after reduction of V(T). Cardiac index, heaart rate and pulmonary arterial pressure increased significantly after V(T) reduction. The increase in cardiac output was observed in all patients. However, despite a mean 25% increase in cardiac output after V(T) reduction, no significant increase in mean GMBF was observed, and individual GMBF responses were heterogeneous.


CONCLUSIONS
V(T) reduction in patients with ARDS, despite resulting in an increase in cardiac output, did not change gastric mucosal perfusion. The heterogeneity in the individual response of GMBF to V(T) reduction could be due to opposite direct (i.e., local vasodilatory effect) and indirect (i.e., global sympathetic stimulation) effects of hypercapnia on gut vessels.
Sitbon
P
P
Service d'Anesthésie-Réanimation, Hĵpital de Bicêtre, Assistance Publique des Hopitaux de Paris, Le Kremlin-Becêtre France.
Teboul
J L
JL
Duranteau
J
J
Anguel
N
N
Richard
C
C
Samii
K
K
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005753:Gastric Mucosa / Q000098:blood supply*; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration; D011446:Prospective Studies; D012039:Regional Blood Flow; D012128:Respiratory Distress Syndrome / Q000503:physiopathology* / Q000628:therapy*; D013990:Tidal Volume