2010 American Heart Association

S834 Circulation November 2, 2010
The pregnant uterus can compress the inferior vena cava,
impeding venous return and thereby reducing stroke volume and
cardiac output. Reports of noncardiac arrest parturients indicate
that left-lateral tilt results in improved maternal hemodynamics
of blood pressure, cardiac output, and stroke volume 96,98,104 ; and
improved fetal parameters of oxygenation, nonstress test, and
fetal heart rate. 100–102
Although chest compressions in the left-lateral tilt position are
feasible in a manikin study, 105 they result in less forceful chest
compressions than are possible in the supine position. 106 Two
studies found no improvement in maternal hemodynamic or fetal
parameters with 10° to 20° left-lateral tilt in patients not in
arrest. 107,108 One study reported more aortic compression at 15°
left-lateral tilt compared with a full left-lateral tilt. 97 In addition,
aortic compression has been found at �30° of tilt, 109 however
the majority of these patients were in labor.
If left-lateral tilt is used to improve maternal hemodynamics
during cardiac arrest, the degree of tilt should be maximized.
However, at a tilt �30° the patient may slide or roll off the
inclined plane, 106 so this degree of tilt may not be practical
during resuscitation. Although important, the degree of tilt is
difficult to estimate reliably; 1 study reported that the degree of
table tilt is often overestimated. 110 Using a fixed, hard wedge of
a predetermined angle may help.
Figure 1. Maternal cardiac
arrest algorithm.
Two studies in pregnant women not in arrest found that
manual left uterine displacement, which is done with the patient
supine, is as good as or better than left-lateral tilt in relieving
aortocaval compression (as assessed by the incidence of hypotension
and use of ephedrine). 111,112
Therefore, to relieve aortocaval compression during chest
compressions and optimize the quality of CPR, it is reasonable
to perform manual left uterine displacement in the supine
position first (Class IIa, LOE C). Left uterine displacement can
be performed from either the patient’s left side with the
2-handed technique (Figure 2) or the patient’s right side with the
1-handed technique (Figure 3), depending on the positioning of
the resuscitation team. If this technique is unsuccessful, and an
appropriate wedge is readily available, then providers may
consider placing the patient in a left-lateral tilt of 27° to 30°, 106
using a firm wedge to support the pelvis and thorax (Figure 4)
(Class IIb, LOE C).
If chest compressions remain inadequate after lateral uterine
displacement or left-lateral tilt, immediate emergency cesarean
section should be considered. (See “Emergency Cesarean Section
in Cardiac Arrest,” below.)
Airway
Airway management is more difficult during pregnancy
(see “ACLS Modifications: Airway,” below), and placing the
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