Peritoneal Vacuum Therapy to Reduce Inflammatory Response From Abdominal Sepsis/Injury (SAD)

• Systemic inflammatory marker levels and peritoneal fluid inflammatory marker levels [ Time Frame: admission to dicharge, expected average of hospital stay 4 weeks. ]
  Intra-peritoneal and plasma inflammatory mediators will be measured on a treatment allocation basis immediately after initiation of the TAC, and thereafter at 2, 3, 7 and 28 days. The mediators studied will include, but are not limited to TNF-α, IL-1β, IL-6, IL-10, IL-12, and CRP.
  
  

• Physiological Outcomes [ Time Frame: admission to hospital discharge; expected average of hospital stay 4 weeks. ]
  Determination of the type and activation status of inflammatory cells present in the peritoneal fluid, Measurement of the activation potential of peritoneal fluid, Peritoneal fluid drainage volume, Post-operative fluid balance, Mean 24 hour intra-abdominal pressure (IAP), daily WSACS IAH grading classification, APACHE II score, SOFA score, PaO2/FiO2 ratio, Oxygenation Index, Vasopressor Requirements,RIFLE score, Need for renal replacement therapy, Mean 24 hour lactate level, Mean 24 hour enteral tolerance (if no anastomosis)
  
  
• Global Outcomes [ Time Frame: patients will be followed-up for 6 months ]
  Death, days with fascial closure for the month after admission, ventilator free days for the month after admission, ICU free days from the month after admission, days free of renal replacement therapy.
  
  

Excessive pressure within the peritoneal cavity, known as intra-abdominal hypertension (IAH), can adversely affect not only intra-peritoneal organ function, but also other organ systems throughout the body. When IAH > 20 mmHg induces new organ dysfunction, a potentially lethal condition known as the abdominal compartment syndrome (ACS) is defined. Practically, this syndrome can be considered multi-system organ failure occurring from severe IAH. While the physical effects of IAH/ACS are increasingly being described, the humoral ones, related to IAH-induced ischemia are poorly understood. Recent animal work suggests that aggressively removing intra-peritoneal fluids, assumed to be vasoactive mediator-rich, leads to better systemic outcomes. There is no human data to support this however. Previous attempts at peritoneal drainage in inflammatory conditions such as sepsis and pancreatitis where not conclusive, but this may have been due to the inefficiency of the systems used and the lack of attention to IAH. Recently, efficient systems providing a temporary abdominal closure (TAC) to both drain intra-peritoneal fluids and to control IAH have been introduced. One of these dressing systems, known as the KCI AbThera™ Abdominal Dressing is currently approved for use in Canada as a temporary abdominal closure (TAC) device but its role in ameliorating systemic sepsis/SIRS has not been evaluated.

We propose a randomized trial of using either the "home Calgary Stampede Vac" involving wall suction or the KCI AbThera™ Abdominal Dressing, to dress the abdomen whenever the operative surgeon determines that an open abdomen is warranted to treat the patient.

In general, others have hypothesized that cytokines, especially peritoneal levels, are sensitive indicators of the post-operative inflammatory reaction and may predict complications. In experimental models IL-6 levels are higher in non-survivors. Further, previous work has noted that the blood level of IL-6, which has a longer half life than TNF-α or IL-1β, is a good index of the overall cytokine cascade activation. Thus the main outcomes to be compared will be between mean cytokine levels measured in each of the two treatment groups - to determine if the KCI AbThera™ Abdominal Dressing can significantly reduce the blood concentration of IL-6 when compared with the "Stampede VAC" system. We are hoping to better understand how the body responds to the inflammatory process that naturally occurs during and after an episode of intra-abdominal hypertension, to identify signals or markers of inflammation and infection as well as its progression and outcome.