Partial Aortic Occlusion:

Zone 1 – 2 hours; Zone 3 – 4 hours

Distal SBP => 20mmHg (20 - 50 mmHg) or MAP ~20 mmHg

Partial aortic occlusion is defined as having partial blood flow past the balloon to minimize the risk of ischemia with longer occlusion times. In the absence of measuring flow, the best clinical surrogate is blood pressure. To accurately control inflation, the user will need to monitor the pressures proximal and distal to the inflated balloon. Two arterial line transducers and set ups are required to accomplish this. Similarly, during prolonged aortic occlusion, monitoring blood the proximal and distal pressures is necessary to determine the extent of partial occlusion. The distal mean arterial pressure is more accurately correlated with flow below the balloon than the above the balloon pressure.59 The minimum recommended distal SBP considered to be a successful partial occlusion is 20 mmHg,39 with a desirable target systolic blood pressure range of 20 - 50 mmHg.49 If utilizing MAP instead of SBP it is recommended to maintain a MAP of 20 mmHg (below the balloon) since MAP and SBP are very close in this low-pressure range. This increases the occlusion time in Zone 1 to at least 2 hours and Zone 3 to at least 4 hours in both preclinical and clinical data.38-39 Due to the semi compliant design of the pREBOA-PRO™ catheter, several investigators have documented that inflation of the balloon does not need to be adjusted after initial setting of below MAP.39

The provider, or assistant, should promptly document placement time, pre-/post-placement blood pressure and MAP, and REBOA insertion distance. Use the Aortic Occlusion (AO) procedure note that is found in Appendix F for specific REBOA documentation. Whether using a complete or partial occlusion catheter, balloon volume and inflation time should be noted at the insertion site for reference by all providers caring for the patient. The provider is responsible for prevention of catheter migration, particularly during patient transport. A provider who is knowledgeable about the management of REBOA should attend to the patient while awaiting definitive surgical repair, to include transport. The trained provider is responsible for ensuring a safe and competent hand off.