Janeth Chiaka Ejike

Intra-abdominal hypertension and the abdominal compartment syndrome: updated consensus definitions and clinical practice guidelines from the World Society of the Abdominal Compartment Syndrome

PurposeTo update the World Society of the Abdominal Compartment Syndrome (WSACS) consensus definitions and management statements relating to intra-abdominal hypertension (IAH) and the abdominal compartment syndrome (ACS).MethodsWe conducted systematic or structured reviews to identify relevant studies relating to IAH or ACS. Updated consensus definitions and management statements were then derived using a modified Delphi method and the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) guidelines, respectively. Quality of evidence was graded from high (A) to very low (D) and management statements from strong RECOMMENDATIONS (desirable effects clearly outweigh potential undesirable ones) to weaker SUGGESTIONS (potential risks and benefits of the intervention are less clear).ResultsIn addition to reviewing the consensus definitions proposed in 2006, the WSACS defined the open abdomen, lateralization of the abdominal musculature, polycompartment syndrome, and abdominal compliance, and proposed an open abdomen classification system. RECOMMENDATIONS included intra-abdominal pressure (IAP) measurement, avoidance of sustained IAH, protocolized IAP monitoring and management, decompressive laparotomy for overt ACS, and negative pressure wound therapy and efforts to achieve same-hospital-stay fascial closure among patients with an open abdomen. SUGGESTIONS included use of medical therapies and percutaneous catheter drainage for treatment of IAH/ACS, considering the association between body position and IAP, attempts to avoid a positive fluid balance after initial patient resuscitation, use of enhanced ratios of plasma to red blood cells and prophylactic open abdominal strategies, and avoidance of routine early biologic mesh use among patients with open abdominal wounds. NO RECOMMENDATIONS were possible regarding monitoring of abdominal perfusion pressure or the use of diuretics, renal replacement therapies, albumin, or acute component-parts separation.ConclusionAlthough IAH and ACS are common and frequently associated with poor outcomes, the overall quality of evidence available to guide development of RECOMMENDATIONS was generally low. Appropriately designed intervention trials are urgently needed for patients with IAH and ACS.

Cerebral oxygenation in neonatal and pediatric patients during veno-arterial extracorporeal life support.

Objective: To observe the effects of right carotid artery ligation and variations in extracorporeal life support (ECLS) flow on regional cerebral oxygenation index (rSO2i) measured using near infrared spectroscopy. Design: Prospective observational study. Setting: Tertiary childrens hospital. Patients: Eleven neonatal and pediatric patients requiring veno-arterial ECLS support between June 2000 and March 2003. Interventions: Near infrared spectroscopy probe placement on left and right frontal regions of patients undergoing ECLS, before vessel cannulation or within 24 hrs of initiation of ECLS. Measurements and Main Results: Regional cerebral oxygenation was measured every minute for 72 hrs or until the patient was decannulated. The effect of cannulation on rSO2i from each hemisphere of the brain and the relationship between ECLS flow and rSO2i during ECLS support and “trialing off” periods were determined. Ligation of the right carotid artery resulted in a 12–25% decrease in rSO2i from baseline in the right frontal region for a duration ranging from 17 to 45 mins before returning toward baseline. No substantial change in the left frontal region rSO2i was detected during cannulation. Following this depression in rSO2i on the right, there was a transient increase above baseline in rSO2i observed in both hemispheres on initiating ECLS. No correlation between ECLS flow and rSO2i was found over the 72-hr period. Periods of “trialing off” ECLS were not related to any change in rSO2i in either hemisphere. Conclusions: This study demonstrated no relationship between ECLS flow and rSO2i changes during the 72-hr observation period. A brief period of cerebral oxygen desaturation of the right frontal region at the time of right carotid ligation was seen in all three study patients examined during cannulation, followed by an increased rSO2i with initiation of ECLS flow. Near infrared spectroscopy measurement may offer an important adjunct for neurologic monitoring of ECLS patients.

Methodological background and strategy for the 2012-2013 updated consensus definitions and clinical practice guidelines from the abdominal compartment society.

The Abdominal Compartment Society (www.wsacs.org) previously created highly cited Consensus Definitions/Management Guidelines related to intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS). Implicit in this previous work, was a commitment to regularly reassess and update in relation to evolving research. Two years preceding the Fifth World Congress on Abdominal Compartment Syndrome, an International Guidelines committee began preparation. An oversight/steering committee formulated key clinical questions regarding IAH/ /ACS based on polling of the Executive to redundancy, structured according to the Patient, Intervention, Comparator, and Outcome (PICO) format. Scientific consultations were obtained from Methodological GRADE experts and a series of educational teleconferences were conducted to educate scientific review teams from among the wscacs. org membership. Each team conducted systematic or structured reviews to identify relevant studies and prepared evidence summaries and draft Grades of Recommendation Assessment, Development and Evaluation (GRADE) recommendations. The evidence and draft recommendations were presented and debated in person over four days. Updated consensus definitions and management statements were derived using a modified Delphi method. A writingcommittee subsequently compiled the results utilizing frequent Internet discussion and Delphi voting methods to compile a robust online Master Report and a concise peer-reviewed summarizing publication. A dedicated Paediatric Guidelines Subcommittee reviewed all recommendations and either accepted or revised them for appropriateness in children. Of the original 12 IAH/ACS definitions proposed in 2006, three (25%) were accepted unanimously, with four (33%) accepted by > 80%, and four (33%) accepted by > 50%, but required discussion to produce revised definitions. One (8%) was rejected by > 50%. In addition to previous 2006 definitions, the panel also defined the open abdomen, lateralization of the abdominal musculature, polycompartment syndrome, abdominal compliance, and suggested a refined open abdomen classification system. Recommendations were possible regarding intra-abdominal pressure (IAP) measurement, approach to sustained IAH, philosophy of protocolized IAP management and same-hospital-stay fascial closure, use of decompressive laparotomy, and negative pressure wound therapy. Consensus suggestions included use of non-invasive therapies for treating IAH/ACS, considering body position and IAP, damage control resuscitation, prophylactic open abdomen usage, and prudence in early biological mesh usage. No recommendations were made for the use of diuretics, albumin, renal replacement therapies, and utilizing abdominal perfusion pressure as a resuscitation-endpoint. Collaborating Methodological Guideline Development and Clinical Experts produced Consensus Definitions/Clinical Management statements encompassing the most contemporary evidence. Data summaries now exist for clinically relevant IAH/ACS questions, which will facilitate future scientific reanalysis.

WSACS — The Abdominal Compartment Society. A Society dedicated to the study of the physiology and pathophysiology of the abdominal compartment and its interactions with all organ systems

WSACS--The Abdominal Compartment Society. A Society dedicated to the study of the physiology and pathophysiology of the abdominal compartment and its interactions with all organ systems.

Intra-abdominal hypertension and abdominal compartment syndrome in pancreatitis, paediatrics, and trauma

Intra-abdominal hypertension (IAH) is an important contributor to early organ dysfunction among patients with trauma and sepsis. However, the impact of increased intra-abdominal pressure (IAP) among pediatric, pregnant, non-septic medical patients, and those with severe acute pancreatitis (SAP), obesity, and burns has been studied less extensively. The aim of this review is to outline the pathophysiologic implications and treatment options for IAH and abdominal compartment syndrome (ACS) for the above patient populations. We searched MEDLINE and PubMed to identify relevant studies. There is an increasing awareness of IAH in general medicine. The incidence of IAH and, to a lesser extent, ACS is high among patients with SAP. IAH should always be suspected and IAP measured routinely. In children, normal IAP in mechanically ventilated patients is approximately 7 ± 3 mm Hg. As an IAP of 10-15 mm Hg has been associated with organ damage in children, an IAP greater than 10 mm Hg should be considered IAH in these patients. Moreover, as ACS may occur in children at an IAP lower than 20 mm Hg, any elevation in IAP higher than 10 mm Hg associated with new organ dysfunction should be considered ACS in children until proven otherwise. Monitor IAP trends and be aware that specific interventions may need to be instituted at lower IAP than the current ACS definitions accommodate. Finally, IAH and ACS can occur both in abdominal trauma and extra-abdominal trauma patients. Early mechanical hemorrhage control and the avoidance of excessive fluid resuscitation are key elements in preventing IAH in trauma patients. IAH and ACS have been associated with many conditions beyond the general ICU patient. In adults and in children, the focus should be on the early recognition of IAH and the prevention of ACS. Patients at risk for IAH should be identified early during their treatment (with a low threshold to initiate IAP monitoring). Appropriate actions should be taken when IAP increases above 20 mm Hg, especially in patients developing difficulty with ventilation. Although on-operative measures should be instituted first, one should not hesitate to resort to surgical decompression if they fail.

Update from the Abdominal Compartment Society (WSACS) on intra-abdominal hypertension and abdominal compartment syndrome: past, present, and future beyond Banff 2017

1Regional Trauma Services and Departments of Surgery and Critical Care Medicine, Foothills Medical Centre, Calgary, Alberta, Canada 2Letterkenny University Hospital, Letterkenny, Donegal Ireland 3Regional Trauma Services, Foothills Medical Centre, Calgary, Alberta, Canada 4Department of Surgery, Division of Trauma — University of Campinas, São Paulo, Brazil 5Department of Surgery, Foothills Medical Centre, Calgary, Alberta, Canada 6Department of Critical Care Medicine, Ghent University Hospital, Gent, Belgium 7Abdominal Center, Helsinki University Hospital, Helsinki Finland 8Loma Linda, California, USA 9University of Tartu, Estonia; and Lucerne Cantonal Hospital, Switzerland 10University of New South Wales-South Western Sydney Clinical School, Sydney, Australia 11Intensive Care Unit, Fiona Stanley Hospital, Murdoch, Australia and School of Surgery, The University of Western Australia, Sterling Highway, Crawley (Perth), Australia 12Department of Intensive Care and High Care Burn Unit, Ziekenhuis Netwerk Antwerpen, ZNA Stuivenberg, Antwerp, Belgium, and Department of Intensive Care, University Hospital Brussel (UZ Brussel), Jette, Belgium, The Free University of Brussels (VUB)

Mesenteric ischemia, intra-abdominal hypertension, and the abdominal compartment syndrome.

In the Winter 2015 issue of Plastic Surgery, Sun et al (1), in their report “Ischemic bowel as a late sequela of abdominal compartment syndrome secondary to severe burn injury”, reported a case of a presumably ischemic complication likely attributable to multiple episodes of the secondary and recurrent abdominal compartment syndrome (ACS) in a young child. This report and the author’s discussion is an important and timely addition to the admittedly sparse literature concerning mesenteric ischemia, intra-abdominal hypertension (IAH) and ACS, particularly in the burn population, raising many points that warrant further consideration and potentially directing future research efforts. As the authors explain, it has long been assumed that mesenteric ischemia is a critical concern with pathologically raised intraabdominal pressure, one that facilitates bacterial translocation and exacerbates the biomediator burden driving multisystem organ failure (2). In animals, even low levels of IAH have been shown to greatly diminish mucosal perfusion, disrupt the gut mucosa, alter the protein expression of tight junctions, increase the mucosal permeability and to drive endotoxin systematically (3-5). This appears to be a compelling argument, except that it remains to be proven in humans. The best data remains the experience of Ivatury et al (6), who found that after severe penetrating abdominal trauma, the majority of those with severe grade III IAH (>25 mmHg), had acidotic gut mucosal pHi (7.10±0.2) even without exhibiting the classic signs of overt ACS. In those selected for decompression, the pHi subsequently improved and none developed ACS. Two patients who had no sustained response in pHi and IAH after abdominal decompression progressed to manifest ACS and multiple organ dysfunction syndrome, and subsequently died. Overall, multiple organ dysfunction syndrome points and death were greater in those with IAH than those without. In the case presented by Sun et al (1), it is noteworthy that the sequelae of the likely ischemic small bowel injury became apparent long after the presumed ischemic injury. This may have related to subclinical mucosal injury that healed with scar and no full-thickness perforation. Mohan et al (7) described that, in a porcine model in which postoperative IAH was induced and then relieved, there was small bowel but not large bowel necrosis. Clearly, however, more study is required to understand the full implications for therapy. As the authors also point out, however, although the gut is assumed to be central to IAH/ACS, better human data simply are not available. Many authors share this view and, as such, the terms ‘acute bowel injury’ and ‘acute intestinal distress syndrome’ have been coined (8). The delayed appreciation of these gut-related events may relate to the dramatic clinical events of the overt ACS, with respiratory, cardiovascular and renal failure being obvious and dominating the clinical picture. These overt cases, however, are becoming significantly fewer in contemporary trauma/critical care, attributed largely to radical changes in resuscitation strategies that emphasize restricted crystalloid balanced blood and plasma-based strategies (9,10). This remarkable success in nearly eradicating the ACS has prompted the former World Society of the Abdominal Compartment Syndrome to rebrand as the World Society of the Abdominal Compartment, emphasizing a new emphasis on trying to understand the more complicated role of IAH in critical illness/injury, and to focus on the study and care of the entire abdominal compartment rather than a single syndrome. Thus, any data and discussion of the more subtle aspects of IAH, such as its role in gut disorders, are greatly encouraged. Regardless of the name of the professional society, or institution, there remains tremendous work still to be done in understanding IAH/ ACS in both burns and the pediatric patient. In this particular case report, the child underwent standard resuscitation with crystalloid fluid. There is suggestive nonrandomized evidence that hypertonic fluids may reduce the risk for secondary ACS with lower fluid load in burn shock patients (11). However, more study is needed because large-volume crystalloid resuscitation remains the most common approach to fluid resuscitation of burn shock. Judiciousness is essential, because modern burn resuscitation frequently grossly exceeds volumes predicted by the Parkland formula (12,13), and other formulas. Thus, it may not be surprising that it remains accepted – if not expected – that nearly all patients with large burns (>60% to 70% body surface area), especially with smoke inhalation, will develop severe IAH/ACS (12,14,15). Given this expected risk, we believe it is mandatory, not elective, to measure IAP in all severe burns, regardless of the physical examination of the abdomen, because clinical examination has proven inaccurate (16,17). Another important point to emphasize is that the patient in question was clearly a young child, in whom the standard ranges for IAH/ ACS based on adult populations are not applicable. The recent guidelines from the Abdominal Compartment Society state that ACS in children is defined as a sustained elevation in IAP >10 mmHg associated with new or worsening organ dysfunction that can be attributed to elevated IAP (18). Thus, this child’s ACS was of longer duration and severity than may have been appreciated. It is unstated whether IAPs were measured to document resolution of the first episode of secondary ACS, although there was clear resolution and return to normal IAP after the use of percutaneous drainage for the two subsequent episodes of recurrent ACS. If medical IAH/ACS management techniques fail to resolve IAH/ACS, it is absolutely recommended to proceed to percutaneous drainage therapies because this may often be quite effective (15,18). The abdominal compliance will typically be a steep part of the pressure/volume curve such that small reductions in volume yield marked improvements in pressure (19). However, vigilance must be maintained such that after successful treatment of IAH, satisfactory levels of IAP are maintained at all times in the management of the critically ill/injured, which simply means measuring IAP levels in patients at risk (20). Another admonition, however, is that we would suggest that bedside ultrasound can greatly increase the safety and effectiveness of percutaneous drainage and we would assume all clinicians caring for the critically ill should be familiar with these techniques. It will never be known whether the eventual stricture causing the small bowel obstruction was related to a potential injury at blind paracentesis, a criticism that can now be completely mitigated by using real-time ultrasound guidance (21). editorial