The effect of different reference transducer positions on intra-abdominal pressure measurement: a multicenter analysis.
OBJECTIVE
To investigate the effect of different reference transducer positions on intra-abdominal pressure (IAP) measurement. Three reference levels were studied: the symphysis pubis; the phlebostatic axis; and the midaxillary line at the level of the iliac crest.


METHODS
Prospective cohort study.


METHODS
The intensive care units of participating hospitals


METHODS
One hundred thirty-two critically ill patients at risk for intra-abdominal hypertension (IAH).


METHODS
In each patient, three sets of IAP measurements were obtained in the supine position, using the different reference levels. The IAP measurements obtained at the different reference levels were compared using a paired t-test and Bland-Altman statistics were calculated.


RESULTS
IAP(phlebostatic) (9.9 +/- 4.67 mmHg) and IAP(pubis) (8.4 +/- 4.60 mmHg) were significantly lower that IAP(midax) (12.2 +/- 4.66 mmHg; p < 0.0001 for both comparisons). The bias between the IAP(midax) and IAP(pubis) was 3.8 mmHg (95% CI 3.5-4.1) and 2.3 mmHg (95% CI 1.9-2.6) between the IAP(midax) and the IAP(phlebostatic). The precision was 3.03 and 3.40, respectively.


CONCLUSIONS
In the supine position, IAP(midax) is higher than both IAP(phlebostatic) and IAP(pubis), differences found to be clinically significant; therefore, the symphysis pubis or phlebostatic axis reference lines are not interchangeable with the midaxillary level.
De Waele
Jan J
JJ
Surgical Intensive Care Unit, Ghent University Hospital, De Pintelaan 185, 9000, Gent, Belgium. jan.dewaele@UGent.be
De Laet
Inneke
I
De Keulenaer
Bart
B
Widder
Sandy
S
Kirkpatrick
Andrew W
AW
Cresswell
Adrian B
AB
Malbrain
Manu
M
Bodnar
Zsolt
Z
Mejia-Mantilla
Jorge H
JH
Reis
Richard
R
Parr
Michael
M
Schulze
Robert
R
Compano
Sonia
S
Cheatham
Michael
M
D000005:Abdomen; D003161:Compartment Syndromes / Q000175:diagnosis* / Q000503:physiopathology; D016638:Critical Illness; D006801:Humans; D007362:Intensive Care Units; D011312:Pressure