Is clinical assessment of the circulation reliable in postoperative cardiac surgical patients?
OBJECTIVE
To study adult patients in the immediate postoperative period after cardiac surgery and determine whether cardiac output (CO) and systemic vascular resistance (SVR) are generally within normal limits and whether clinical assessment of CO provides an adequate approximation to guide treatment.


METHODS
Prospective study.


METHODS
Overnight intensive recovery unit, St Thomas' Hospital, London.


METHODS
Fifty patients who had undergone cardiac surgery within the previous 5 hours and whose COs were not being measured.


METHODS
The physician (if present) or nurse managing the patient was asked to make a clinical estimate (as low, normal, or high) of CO and of SVR. CO was measured by lithium dilution. The clinically estimated values were compared with the measured values, after adjusting for patient size.


RESULTS
In 29 of 50 (58%) patients, cardiac index (CI) (20 of 50 [40%] patients) or systemic vascular resistance index (SVRI) (22 of 50 [44%] patients) was outside normal limits (CI, 2.7 (plus minus 30%) L/min/m(2); SVRI, 2,500 (plus minus 30%) dyne center dot sec center dot cm(minus sign 5)/m(2)). When CI was outside the normal range, the clinical estimate was usually wrong (13 of 20 [65%]); when SVRI was outside the normal range, the clinical estimate was also usually wrong (16 of 22 [73%]).


CONCLUSIONS
In the early postoperative period after cardiac surgery, clinical assessment of the circulatory state is frequently misleading, and there should be a low threshold for measuring CO.
Linton
Robert A F
RA
Rayne Institute, St. Thomas' Hospital, London, United Kingdom. robert@foxlinton.demon.co.uk
Linton
Nick W F
NW
Kelly
Fiona
F
D000368:Aged; D001794:Blood Pressure; D002302:Cardiac Output; D006348:Cardiac Surgical Procedures; D006801:Humans; D007201:Indicator Dilution Techniques; D018021:Lithium Chloride; D008875:Middle Aged; D011183:Postoperative Complications; D011184:Postoperative Period; D011446:Prospective Studies; D012016:Reference Values; D014655:Vascular Resistance
D018021:Lithium Chloride