Cardiovascular effects of rapid fluid infusion during anesthesia
Iwasawa, H.
Masui. Japanese Journal of Anesthesiology 36(9): 1414-1421
1987
ISSN/ISBN: 0021-4892 PMID: 2447301 Document Number: 293025
In this study we tried to clarify the mechanisms of V waves on PCWP and investigated the cardiovascular effects of rapid fluid loading during anesthesia. Under epidural analgesia with rapid infusion of 500 ml of hydroxyethyl starch solution (Hespander), PCWP, CVP and CI increased significantly but HR, SVR and MAP decreased compared with the control values. With echocardiography, left ventricular end-diastolic diameter (LVDd) and end-systolic diameter (LVDs), left atrial diameter (LAD) and inferior vena cava diameter (IVCD) increased significantly but ejection fraction (EF) was unchanged. In 18 cases, V waves ranged over 5 mmHg in height were observed and with ultrasonic pulse Doppler method. Slight MR was observed in 12 cases. In contrast to the findings observed during epidural analgesia, quite different changes were observed during general anesthesia; LVDd did not increase and CI, EF and MAP decreased further. V waves were observed in only 4 cases. In our study, hypotension during either epidural or general anesthesia could not be treated by rapid fluid infusion. During epidural analgesia, function of right ventricle may be maintained and so rapid fluid infusion caused the increase of pre-load. Pulmonary venous compliance was decreased by this increase of preload and V waves were observed as the sign of volume loading. On the other hand, during general anesthesia functions of both left and right ventricles were depressed markedly and so the increase of pre-load did not occur. Rapid fluid loading has been utilized for the management of hypotensive episode during anesthesia but from our results, this is not so effective, and utilization of cardiotonic or sympathomimetic agents may be necessary.