Hello, my name is Laura Moore and I'm a professor of surgery at UTHealth McGovern Medical School and the Chief of Surgical Critical Care at the Red Duke Trauma Institute in Houston, Texas. Today I'm going to talk to you about damage control and the use of the open abdomen. I have the following financial disclosures. So over the next 20 minutes, I'm going to review the history of the open abdomen and how its use has evolved into modern time. Then we'll transition into discussing the current clinical indications for the use of damage control laparotomy. And then finally, we'll close with some special considerations for how to manage patients with an open abdomen in the intensive care unit. So the first clinical description of an open abdomen is from The Lancet in 1940. Sir William Ogilvie described the use of a light canvas or cotton cloth that had been sterilized, covered with Vaseline, and then sewn to the fascial edges with interrupted cat gut sutures. He described the temporary nature of the device, but said that it was useful in allowing retention of abdominal contents and use of abdominal wall musculature during respiration. Now evolving into more modern times, the description of the lethal triad or the bloody vicious cycle that we commonly see in bleeding trauma patients of coagulopathy, metabolic acidosis, and hypothermia has led to the utilization of the open abdomen as a temporizing measure to allow for temporary hemostasis, control of contamination, and then resuscitation of the patient in the ICU, with plans to come back to the operating room at a later time for definitive operative fixation. Now the term damage control was first described in the surgical realm by Michael Rotundo in this paper that was published in the Journal of Trauma in 1993. Now the term damage control itself is actually from the US Navy. And this term refers to a temporary fix that allows a damaged vessel to be temporarily secured by sealing off certain damaged compartments and then allowing that vessel to sail back to port for definitive repairs. So the term was then adopted to the trauma literature as a technique to improve survival in the hemorrhaging trauma patient with abdominal injuries. The goals of damage control were to achieve hemostasis, control contamination, and then apply a temporary closure to the abdomen in order to facilitate further resuscitation in the ICU. Now other reasons why we might have an open abdomen were related to iatrogenic abdominal compartment syndrome that was created by the resuscitation practices of the time. This paper that was published in the Archives of Surgery in 2003 describes a very common scenario in the trauma population during that time frame. During the 1990s and early 2000s, crystalloid-based resuscitation of the trauma patient was common practice. A lot of this resuscitation practice was driven by some of the sentinel work by Dr. Shoemaker in which their belief was that supernormal resuscitation would improve patient outcomes. As part of this supernormal resuscitation, patients were given large volumes of crystalloid. But what they found was that large volumes of crystalloid that were required to deliver a supernormal resuscitation increased the rates of intra-abdominal hypertension, abdominal compartment syndrome, multiple organ failure, and death. This paper was published by Fred Moore in Shock in 2009, and it described the practice of large-volume crystalloid-based resuscitation that was going on in the trauma population at that time. And as you can see, prior to ICU arrival, it was not unusual for patients to get five to six liters of crystalloid followed by an additional eight to nine liters of crystalloid in the ICU. And then you contrast that with the minimal blood products that these patients were receiving, and you see very quickly that these patients were getting up to 20 liters of crystalloid as part of their hemorrhagic shock resuscitation. And this is what happened. This is a patient from our shock trauma ICU from 2006. This patient was in hemorrhagic shock on arrival from blunt mechanism of injury. He received 14 units of PAX cells, three units of FFP. He did not get any platelets. He did not get any cryoprecipitate, so a very unbalanced resuscitation in terms of the blood products used. But in addition, and more importantly, this patient got 25 liters of crystalloid within the first 24 hours of admission. And this was the result. This patient developed abdominal compartment syndrome, had to have a decompressive laparotomy to treat that, and then as a result, had an open abdomen. Fortunately, our resuscitation practices have dramatically changed in the trauma world over the last 10 years due largely to the results of these two prospective multicenter trials evaluating the use of balanced blood product resuscitation. The proper trial really revolutionized and solidified the use of blood products for resuscitation in a one-to-one-to-one ratio, showing decreased death due to hemorrhage in the first 24 hours and shortened time to hemostasis. And as a result, we have shifted largely away from crystalloid-based resuscitations. And now standard of care is one-to-one-to-one blood product resuscitation or whole blood for patients in hemorrhagic shock. So for the non-surgeons in the room, just to go over the phases of damage control laparotomy that would result in a patient having an open abdomen, phase one is to stop bleeding and control contamination. So these are patients that are in extremis. We need to do the minimum thing we need to do to save the patient in the operating room. And we take the patient to the ICU, where they are warmed, they are resuscitated, and their coagulopathy is corrected. Again, this is focusing on reversing that bloody vicious cycle that we see in patients in severe hemorrhagic shock. And then phase three, which usually happens 24 to 48 hours after that index operation, is that this patient returns to the operating room for definitive repair. That will include removal of packing, restoration of bowel continuity, and then hopefully closure of the abdomen. So let's talk now about the types of patients that would be candidates for a damage control laparotomy and might land in your ICU with an open abdomen. So much of the early work on damage control laparotomy and its indications comes from the group in Denver. Gene Moore and colleagues published their indications in 1996 for damage control. That included bleeding due to coagulopathy, inaccessible major venous injury, i.e. massive liver hemorrhage from a retrohepatic vena cava injury. The third would be need for a time-consuming surgical procedure, such as a Whipple, which really shouldn't be undertaken in a patient that's under-resuscitated and acidotic. The fourth indication, which is a little less common today, is the need for a control of extra-abdominal life-threatening injury. Remember at the time this paper was published, 1996, while pelvic angiography was available, hybrid operating rooms really were not something that was available in a hospital setting. And so performing these procedures required removing the patient from the operating room and taking them to the radiology department for these interventions to be done. And then, of course, inability to close the abdomen due to visceral edema during resuscitation or need for a second look laparotomy. They also identified some predictors of patients that would require an open abdomen. That included intraoperative coagulopathy, large volume or massive transfusion within the first four hours, persistent acidosis, and obviously hypothermia with a temperature of less than 34. Fast forward to a more modern paper. This was from the group here in Houston in 2016, published in the American Journal of Surgery. And as you'll see, our indications in modern day were predominantly for packing. So these were patients that had significant solid organ injury of the liver or the kidney that required packing for hemostasis. And we would typically leave these patients with significant liver injuries packed for 24 to 48 hours, plus minus visceral angiography for hemostasis before taking back to the operating room. And then some other patients required second look, had persistent hemodynamic instability, or had risk for abdominal compartment syndrome. So the currently accepted indications for leaving an abdomen open at the index operation really haven't changed that much. Again, persistent acidosis, hypothermia, coagulopathy, need for packing for hemostasis, presence of visceral edema. Someone that you as the surgeon consider at high risk for development of abdominal compartment syndrome. Someone who is persistently hypotensive despite packing and need for ongoing resuscitation, or need for a second look laparotomy. So what are the downsides to doing a damage control laparotomy and leaving an abdomen open? Well, certainly the biggest downside from a surgical standpoint is our inability to definitively close the fascia at that second take back to the operating room. Fortunately, our closure rates have improved. Again, this is due in large part to changes in our resuscitation practices and our move towards blood-based resuscitation and away from crystalloid-based resuscitation. So here are just some examples of complications that we can see in an open abdomen. This is a patient that not only had an open abdomen, but also had a left anterior lateral thoracotomy with an open chest, and subsequently developed soft tissue infection with loss of both skin and muscle of both the abdominal wall and the left chest wall. Very complicated and difficult to get this patient closed. Another very dreaded complication of an open abdomen is the development of inter-atmospheric fistulas. So again, for the non-surgeons in the room, if we're unable to primarily close the fascia, what we have to do is allow the abdominal viscera to granulate. And once there's a granulation bed over the bowel and visceral contents, we perform a split thickness skin graft over this. And then the patient has a large abdominal wall defect that is covered with this layer of split thickness skin graft. Unfortunately, these skin grafts are thin. You can have erosion. And right underneath that, obviously, is the bowel itself. And so you can have the development of inter-atmospheric fistulas, which are very difficult sometimes for us to manage. And then finally, in those patients that do require skin grafting, even if they don't develop a fistula, they all have varying degrees of loss of abdominal domain. And so these are some images here of patients that have had the skin grafts applied to cover the viscera. But they still have very large abdominal wall defects that require significant surgical intervention to provide abdominal wall reconstruction. So let's wrap up by talking about how to take care of patients with an open abdomen in your ICU. So again, most of the open abdomen patients are going to be those patients that have undergone some sort of a damage control procedure in the operating room, typically for hemorrhagic shock. But it could be for septic shock as well. The concept of damage control resuscitation has really pushed the care of the critically injured trauma patient into the future. And a lot of the lessons that we've learned and the practices that we've implemented today were learned during the conflicts in the Middle East and Iraq and Afghanistan. So this concept of damage control resuscitation addresses both the diagnosis and the treatment of the lethal triad that we discussed earlier of coagulopathy, hypothermia, and acidosis. So what are the components of a damage control resuscitation? Well, primarily stopping bleeding. So that can be with temporizing maneuvers such as tourniquets or roboa or abdominal packing. Hypotensive resuscitation. And this means that we accept the fact that a patient's blood pressure is 90, not 120, while we're waiting to achieve hemostasis. There's no benefit to driving the blood pressure up to normal values when a patient is still bleeding. So allowing for a hypotensive resuscitation is critical. Minimizing crystalloid, which we have discussed. Use of whole blood or parched products at ratios of 1 to 1 to 1. Prevention and then, if needed, reversal of hypothermia and acidosis. And then other hemostatic adjuncts to stop bleeding. So these are all key elements in the damage control resuscitation process. So what are some things that you can do when the patient hits the ICU with an open abdomen to improve their chances of successful closure? Well, hypertonic saline is something that many trauma centers have moved towards. This was a study that we published out of Houston a few years ago looking at 77 of our patients that underwent damage control laparotomy. 23 received hypertonic saline and 54 received standard isotonic fluids. And our primary outcome was early fascial closure. When you looked at our results, patients that received hypertonic saline had lower fluid volumes within the first 24 hours, 3.9 liters versus 7.8 liters. But most importantly, patients in the hypertonic saline group that you see there on the right had 100% early primary fascial closure rates, which is what we want to achieve for all these patients that have an open abdomen. The group in Florida at the University of Florida have reported similar outcomes. They looked at 138 patients that underwent damage control laparotomy and had an open abdomen. 60 were in the protocolized care group and 78 were historic controls that received standard care at the discretion of the ICU team. And they hypothesized that protocolizing the care of these patients with the open abdomen would improve fascial closure rates. Their protocol elements included hypertonic saline, as we had described earlier, a vacuum dressing for temporary abdominal closure, and early initiation of nasojejunal feeding. What they found was that patients in the protocolized care group had higher fascial closure rates, 93% versus 81%, with no difference in complications, mortality, or length of stay. Why does hypertonic saline work? Well, it decreases the total volume of crystalloid required in the initial resuscitation. But more importantly, it creates an intravascular osmotic gradient that helps prevent the bowel wall edema that is often seen in the post-resuscitation phase in these critically ill patients. It also helps prevent gut ischemia-induced systemic inflammation. So how should you use it? Give patients 3% sodium chloride at 30 cc's per hour. Do not titrate this. Do not bolus this. And please start it immediately upon arrival in the ICU. You can continue the hypertonic saline for up to 72 hours or until fascial closure is achieved, whichever one comes first. The other really important thing for the intensivist to do when these patients are in their ICU is to optimize patient physiology. Returning to the OR for definitive closure depends upon having normalized physiology. So if it's a trauma patient, make sure that you've corrected their coagulopathy. We use thromboelastography to do directed blood product resuscitation and correction of coagulopathy. Obviously, ensure that the patients are normothermic. And in the setting of maybe the general surgery patient that's in septic shock and underwent a damage control procedure, getting those patients off of vasopressors is critical. Patients are often left in discontinuity in terms of their bowel. So necrotic or injured bowel gets resected and then left in discontinuity as part of the damage control procedure. But in order for us to perform an anastomosis and restore intestinal continuity, the patients have got to be off of vasopressors or that procedure becomes extremely high risk with the concern for failure of that anastomosis. So we typically would like to have patients off of vasopressors before we will perform that intestinal anastomosis. And then finally, as mentioned before, avoid high volumes of crystalloid. In terms of sedation and analgesia, I believe it is a common misconception that patients with open abdomens need to be heavily sedated or paralyzed, and this is not true. Treat them as you would any other patient in terms of starting multimodal analgesia, including PO, if the patient has bowel continuity and is able to take PO meds. But by all means, do not sedate and paralyze these patients just because their abdomen is open. Nutritional support is also critical. Patients with an open abdomen are hypermetabolic and have significant nutritional needs. So starting nutritional support immediately is critical. And starting enteral nutrition within the first 24 hours has been shown to improve both wound healing and fascial closure rates. So in summary, damage control laparotomy saves lives. And the role of the intensivist is to help optimize physiology once the patient arrives in the ICU to improve closure rates. Remember to minimize crystalloid use, hypertonic saline is your friend, and start early enteral nutrition. If you have questions about this presentation, you can email me at the address listed below. And I'd like to thank the planning committee for the clinical congress this year for the invitation to speak. I appreciate it. Thank you for your attention.

damage control

open abdomen

surgical critical care

resuscitation

ICU

complications