CV
Patient meets one of the following
criteria and has at least two risk
factors for IAH:
Patient has IAH
1. New intensive care unit admission
2. Evidence of clinical deterioration
Yes
Measure patient’s IAP to establish baseline pressure
Notify patient’s doctor
of elevated IAP.
IAP measurements should be:
(1) Expressed in mmHg (1 mmHg = 1.36 cm H2O)
(2) Measured at end-expiration
(3) Performed in the supine position
(4) Zeroed at the level of the mid-axillary line
(5) Performed with an instillation volume of no greater
than 25 mL of saline (for bladder technique)
(6) Measured 30-60 seconds after instillation to allow
bladder detrusor muscle relaxation
(for bladder technique)
Inta-abdominal hypertension
assessment algorithm
Sustained IAP >
12 mmHg?
Proceed to IAH/ACS
management algorithm.
No
Patient does not have
IAH. Observe patient, and
recheck IAP if patient deteriorates clinically.
Figure 1: From: Cheatham et al. [25] Intensive Care Med. 2007 Jun; 33(6): 951-62.
Bozeman, Ross
clusion of their repair.
Rasmussen et al. [12] from the Mayo Clinic reported a case
control series of 223 patients treated for rAAA over a tenyear period. Of 90 patients closed primarily and used as
case controls in this study, 10 (11%) developed postoperative ACS and were treated with decompressive laparotomy.
However, it should be noted that 53 patients in this series
were managed with prophylactic delayed closure at the time
of initial operation.
The advent of endovascular repair of abdominal aortic aneurysms has revolutionized the management of abdominal
aortic aneurysms.
Although first successfully performed in 1994 by Marin and
colleagues [31], widespread experience with the use of endovascular techniques for rAAA (REVAR) has lagged elective procedures, but encouragingly, more and more centers
are developing standardized protocols and patient selection
criteria to treat rAAA with endovascular grafts [2, 28].
In 2010, Starnes et al. [30] reported sobering data on the
incidence ACS in rAAA patients managed by open repair
and their subsequent outcomes. Thirty patients of 151
managed by open repair developed ACS (19%). Mortality in
those who developed ACS was 66%.
REVAR, in theory, allows the patient to undergo a less
physiologically challenging procedure, especially given the
multiple co-morbidities carried by patients who present
with rAAA. Care strategies for patients with rAAA have
played a part in the development of REVAR.
Djavani Gidlund, et al. [4] published findings on a consecutive series of 29 patients treated by REVAR and monitored postoperatively utilizing IAP monitoring guidelines
from the 2004 WSACS consensus. IAH was observed in 16
(55%), with 6 patients (21%) developing IAH >20 mmHg
and 3 (10%) of those patients developing ACS.
The term hypotensive hemostasis describes the use of
permissive hypotension to limit both the pathologic and
iatrogenic resuscitative effects of a catastrophic rupture
by limiting the size of the retroperitoneal hematoma and reducing the amount of preoperative transfusions and fluids.
Three (10%) of these patients developed overt ACS. Starnes
et al. [30] reported the development of ACS in 2 of 27
(7.4%) patients managed by REVAR with 1 of the 2 patients
surviving. These data confirm that IAH and ACS occur
commonly in the setting of rAAA whether managed by open
techniques or by REVAR.
5. Abdominal Compartment Syndrome in the Age
of Endovascular Repair
CV DIRECTIONS VOL. 2, NO. 2
Most centers have instituted protocols which tolerate
systolic blood pressure (SBP) of <90 to 80 mmHg or even
lower depending on neurocognitive function as an indicator of instability, thus limiting the volume of resuscitative
fluids and blood products prior to exclusion of the rupture
[1, 5, 28, 32]. Supraceliac aortic balloon occlusion is utilized
in hemodynamically unstable patients for rapid control of
aortic hemorrhage.
REVAR has been performed under general, epidural, and
11