Abdominal compartment syndrome: what radiologist needs to know.

The intra-abdominal hypertension (IAH) and the abdominal compartment syndrome (ACS) are life-threatening conditions with a significant rate of mortality; therefore, early detection is paramount in their optimal management. IAH is diagnosed when the intra-abdominal pressure (IAP) is more than 12 mmHg. It can occur when the intra-abdominal volume increases (ileus, ascites, trauma, pancreatitis, etc.) and/or the abdominal wall compliance decreases. IAH can cause decreased venous flow, low cardiac output, renal impairment, and decreased respiratory compliance. Consequently, these complications can lead to multiple organ failure and induce the abdominal compartment syndrome (ACS) when IAP rises above 20 mmHg. The diagnosis is usually made with intravesical pressure measurement. However, this measurement was not always possible to obtain; therefore, alternative diagnostic techniques should be considered. In this setting, computed tomography (CT) may play a crucial role, allowing the detection and characterization of pathological conditions that may lead to IAH. This review is focused on the pathogenesis, clinical features, and radiological findings of ACS, because their presence allows radiologists to raise the suspicion of IAH/ACS in critically ill patients, guiding the most appropriate treatment.

Computed tomography features predictive of intra-abdominal hypertension in acute necrotizing pancreatitis: A prospective study.

BACKGROUND: Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) in acute pancreatitis (AP) are associated with development and worsening of organ failures and poor prognosis. Limited studies suggest that contrast-enhanced computed tomography (CECT) can predict the presence of IAH/ACS. We aimed to study clinical profile of patients with AP and IAH and identify predictive factors of IAH on CECT abdomen. METHODS: Consecutive patients admitted with moderately severe and severe acute pancreatitis (SAP) were recruited. Clinical and radiological data were recorded prospectively. Intra-abdominal pressure was measured via a urinary catheter to document the presence of IAH/ACS. CECT abdomen was done within the first week of admission and various features that may predict the presence of IAH were studied. RESULTS: Thirty-seven patients (24 SAP) (mean age: 39.78 ± 13.43 years and 67.6% males) with  AP were studied. The most common etiology was alcohol (37.7%). IAH developed in 54.05% of patients; patients with IAH had significantly higher bedside index of severity in AP (BISAP), Acute Physiologic Assessment and Chronic Health Evaluation II (APACHE II) score, persistent acute lung injury (ALI), persistent acute kidney injury (AKI), persistent cardiovascular failure (CVSF), intensive care unit (ICU) stay, and mortality. Among the CT predictors, patients with IAH more commonly had moderate-gross ascites (60% vs. 23.5%, p-value - 0.026), a pancreatic necrosis of > 50% (50% vs. 17.6%, p-value - 0.04), and a round belly sign (RBS) (50% vs. 5.9%, p-value 0.03). On multivariate analysis, only RBS was predictive of  IAH (odds ratio 12.6, 95% confidence interval 1.3-124.2, p-value 0.03). The sensitivity, specificity, positive predictive value, and negative predictive value for RBS were 50%, 94.12%, 90.9%, and 61.54%, respectively. CONCLUSION: Presence of RBS, moderate-gross ascites, and pancreatic necrosis of > 50% on CECT can predict the presence of IAH in these groups of patients.

The use of point-of-care ultrasound to guide clinical management in intra-abdominal hypertension.

INTRODUCTION: The Abdominal Compartment Society (WSACS) developed a medical management algorithm with a stepwise approach to keep intra-abdominal pressure (IAP) ≤ 15 mm Hg. The role of point-of-care ultrasound (POCUS) as a bedside modality in the critical care patients is not well studied in relation to the intra-abdominal hypertension (IAH) management algorithm. AIM: To test the role of point-of-care ultrasound (POCUS) in the medical management of patients with intra-abdominal hypertension (IAH). METHOD: We conducted a prospective observational study. Those who met the inclusion criteria were assigned to undergo POCUS and small bowel ultrasound as adjuvant tools in their IAH management. RESULTS: A total of 22 patients met the inclusion criteria and were included in the study. The mean age of the study participants was 65 ± 22.6 years, 61% were men, and the most frequent admission diagnoses were hepatic encephalopathy and massive ascites (five cases). Ultrasound and abdominal X-rays were comparable in confirming correct NGT position, but the ultrasound was superior in determining the gastric content (fluid vs. solid) and diagnoses of gastric paresis in two cases. Small bowel obstruction was present in four patients and confirmed with abdominal CT; two of the patients underwent surgical intervention for mesenteric vessel occlusion and transmesenteric internal hernia. Enema treatment was found to empty the bowel incompletely 72%, 56%, and 42% of the time on days 1, 2, and 3, respectively. Four patients with cirrhosis admitted with upper gastrointestinal bleeding and hepatic encephalopathy (out of a total of 8) were found to have large amounts of ascites, and US-guided paracentesis was performed. CONCLUSION: POCUS can be used in the nonoperative management of IAH. It is an important tool in the diagnosis and treatment of patients with IAH.

Abdominal perfusion pressure is superior from intra-abdominal pressure to detect deterioration of renal perfusion in critically Ill patients.

BACKGROUND: Intra-abdominal hypertension (IAH) is a frequent cause of acute kidney injury (AKI) among critically ill patients who have risk factors. This study aimed to determine the relation between Abdominal Perfusion Pressure (APP) and AKI showed by the Doppler-based renal resistive index (RRI). METHODS: In this study, 38 patients older than 18 years old who received mechanical ventilation and had risk factors for the development of IAH were prospectively studied. All measurements and parameters were divided into two groups according to renal dysfunction (Group I: RRI <0.72 vs Group II: RRI >0.72). RESULTS: The mean IAPs were not significant between the groups, 11.5±6.9 mm Hg in Group I (n=35) and 13.5±5.8 in Group II (n=33), respectively. APPs were statistically higher in Group I (81.2±13.6) than Group II (66.4±9.5) (p<0.001). The AUC for the association between APP at RRI >0.72 was 0.802 (p<0.001), with the APP ≤72 mmHg having a sensitivity of the 76% (95% CI 58-89%) and a specificity of 71% (95% CI 54-85%). CONCLUSION: Our findings suggest that an APP with a threshold of ≤72 mmHg is associated with a significant increase in renal RRI, which may be predictive of worsening of renal perfusion.

Decompressive laparotomy for abdominal compartment syndrome resulting from severe acute pancreatitis: a case report.

BACKGROUND: Abdominal compartment syndrome (ACS) is associated with mortality in patients with critical illness such as severe acute pancreatitis, but it remains unclear whether decompressive laparotomy for ACS can improve the prognosis of patients. CASE PRESENTATION: A woman in her 60s visited our hospital because of upper abdominal pain. On the basis of her laboratory data and abdominal contrast-enhanced computed tomography findings, acute gallstone pancreatitis was diagnosed. She underwent endoscopic sphincterotomy for the removal of the common bile duct stone. Then, a drainage tube was placed in the bile duct. However, on the 5th hospital day, her intra-abdominal pressure increased to 22 mmHg and renal dysfunction was observed, which led to the diagnosis of ACS. As intensive medical treatments did not improve her ACS, she underwent decompressive laparotomy on the 9th hospital day. Postoperatively, her laboratory data and intravesical pressure improved, and she was discharged from the hospital after abdominal closure, continuous drainage, and antibiotic therapy. CONCLUSION: As the effectiveness of decompressive laparotomy for ACS has not been established, this treatment indication remains controversial. Decompressive laparotomy is considered useful for the management of ACS, if it is performed at an appropriate time, as in the present case.

Multidetector CT Findings in the Abdomen and Pelvis after Damage Control Surgery for Acute Traumatic Injuries.

After experiencing blunt or penetrating trauma, patients in unstable condition who are more likely to die of uncorrected shock than of incomplete injury repairs undergo emergency limited exploratory laparotomy, which is also known as damage control surgery (DCS). This surgery is part of a series of resuscitation steps, with the goal of stabilizing the patient's condition, with rapid surgical control of hemorrhage followed by supportive measures in the intensive care unit before definitive repair of injuries. These patients often are imaged with multidetector CT within 24-48 hours of the initial surgery. Knowledge of this treatment plan is critical to CT interpretation, because there are anatomic derangements and foreign bodies that would not be present in patients undergoing surgery for other reasons. Patients may have injuries beyond the surgical field that are only identified at imaging, which can alter the care plan. Abnormalities related to the resuscitation period such as the CT hypoperfusion complex and ongoing hemorrhage can be recognized at CT. Familiarity with these imaging and clinical findings is important, because they can be seen not only in trauma patients after DCS but also in other patients in the critical care setting. The interpretation of imaging studies can be helped by an understanding of the diagnostic challenges of grading organ injuries with surgical materials in place and the awareness of potential artifacts on images in these patients. Online supplemental material is available for this article. ©RSNA, 2019 See discussion on this article by LeBedis .

First Report of Fatal Secondary Abdominal Compartment Syndrome Induced by Intestinal Gas Accumulation without Organic Occlusive Intestinal Lesion in a Child with Sepsis.

BACKGROUND Abdominal compartment syndrome (ACS), characterized by an increased intra-abdominal pressure and new-onset organ dysfunction, is a critical and potentially fatal condition, with no case of ACS caused by intestinal gas without intestinal lesion being reported to date. CASE REPORT A 2-year-old girl with a chromosomal abnormality of 1p36 deletion presented with fever and diarrhea following upper-gastrointestinal series for the evaluation of gastroesophageal reflux. After 20 days, she experienced septic shock and multiple-organ failure, accompanied with rapidly growing, severe abdominal distension. A marked increase in the intra-abdominal pressure was indicated by the complete loss of elasticity in the extremely hard and distended abdomen. She died 14 h after the onset of shock. Her autopsy examination revealed extensive pneumonia and excessive intestinal gas, despite no occlusive intestinal lesion present. CONCLUSIONS It is critical to be aware that secondary ACS can occur following sepsis due to the accumulation of extensive intestinal gas, without an occlusive intestinal lesion.

A comparison of segmented abdominopelvic fluid volumes with conventional CT signs of abdominal compartment syndrome in a trauma population.

PURPOSE: To compare the utility of abdominopelvic fluid volume measurements with established computed tomography signs for refractory post-traumatic abdominal compartment syndrome. METHODS: This retrospective observational cohort study included 64 consecutive adult trauma patients with preoperative CT and diagnosis of refractory abdominal compartment syndrome requiring decompressive laparotomy at a level I trauma referral center between 2004 and 2014. We hypothesized that abdominal fluid volume measurements would be more predictive of the need for early laparotomy than previously described conventional CT signs of refractory ACS. Abdominopelvic fluid volumes were determined quantitatively using semi-automated segmentation software. The following conventional imaging parameters were recorded: abdominal anteroposterior:transverse ratio (round belly sign); infrahepatic vena cava diameter; distal abdominal aortic diameter; largest single small bowel wall diameter; hydronephrosis, inguinal herniation; and mesenteric and body wall edema. For outcome analysis, patients were stratified into two groups: those who underwent early (< 24 h) and late (≥ 24 h) decompressive laparotomy following CT. Correlation analysis, comparison of means, and multivariate logistic regression were performed. RESULTS: Abdominal fluid volumes (p = 0.001) and anteroposterior:transverse ratio (p = 0.009) were increased and inferior vena cava diameter (p = 0.009) was decreased in the early decompressive laparotomy group. Multivariate analysis including conventional CT variables, fluid volumes, and laboratory values revealed abdominal fluid volumes (p = 0.012; Δ in log odds of 1.002/mL) as the only independent predictor of early decompressive laparotomy. CONCLUSIONS: Segmented abdominopelvic free fluid volumes had greater predictive utility for decision to perform early decompressive laparotomy than previously described ACS-related CT signs in trauma patients who developed refractory abdominal compartment syndrome.

Computed tomographic features of intra-abdominal hypertension in three dogs.

OBJECTIVE: To describe computed tomographic (CT) features of intra-abdominal hypertension (IAH) in 3 dogs with abdominal distension. CASE SUMMARY: Three dogs with anorexia, distended abdomen, or labored breathing were presented for CT imaging. All 3 dogs were premedicated with IV butorphanol (0.2 mg/kg). A Foley urinary catheter was aseptically placed and the transvesical technique was used to obtain intra-abdominal pressure (IAP). The IAP measurements were obtained with the dogs in a standing position after a stabilization period of 5 minutes. The mean IAP values for each of the 3 dogs were 26.0, 12.0, and 13.0 mm Hg. Anesthesia was induced with IV propofol (2.0-4.0 mg/kg, to effect) in all 3 dogs and maintained with sevoflurane in 2 dogs. Compression of the caudal vena cava and elevation of the diaphragm were observed in all 3 dogs, whereas renal compression and the extension of peritoneal fluid to the vaginal canal and cavity were seen in the dog with the highest IAP. NEW OR UNIQUE INFORMATION PROVIDED: Compression of the caudal vena cava, direct renal compression, and the extension of peritoneal fluid into the vaginal canal and vaginal cavity are consistent with a diagnosis of IAH. Measurement of IAP and detection of these CT features should alert clinicians to the possible presence of IAH in veterinary patients.

Abdominal compartment syndrome and intra-abdominal hypertension in critically ill patients: diagnostic value of computed tomography.

AIMS: The aims of the present work were to reevaluate, prospectively, the diagnostic value of already-described computed tomography (CT) landmarks of intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) and to study the diagnostic value of some undescribed CT signs for the diagnosis of IAH and ACS. MATERIALS AND METHODS: Consecutive patients admitted to the intensive care unit (ICU) in shock for whom an abdominal CT was clinically indicated were included. CT examinations were reviewed and scored by two reviewers for the 12 proposed CT features of IAH and ACS. Intravesical pressure (IVP) was measured for each patient. Imaging features and clinical data of patients with IAH (IVP ≥ 12 mmHg) were compared to those of patients with normal intra-abdominal pressure (IVP < 12 mmHg). RESULTS: Forty-one patients were included. Twenty-one patients (51%) presented IAH with an IVP value ≥ 12 mmHg. Four patients (10%) were considered to have ACS (10%). Only an increased peritoneal-to-abdominal height ratio (PAR) was associated with the presence of IAH (PAR = 0.45 [0.40-0.49] in patients with IVP < 12 mmHg and PAR = 0.52 [0.48-0.53] in patients with IVP ≥ 12 mmHg; p < 0.001). Increased PAR ≥ 0.52 had a specificity of 85% for IAH diagnosis. CONCLUSION: The present study suggests that a PAR ≥ 0.52 could help radiologists to identify IAH on abdominal CT scan and could lead to adequate identification and/or treatment, even at early stages of IAH. KEY POINTS: • CT is an efficient first-intention procedure to evaluate and follow up underlying conditions in critically ill patients at risk of IAH and ACS overcome. • Raising the possibility of an IAH on a CT examination is relevant information for the clinician. • The only factors associated with intra-abdominal hypertension were the peritoneal-to-abdominal height ratio (PAR) and the ratio of maximal anteroposterior to transverse abdominal diameter (which define the round belly sign when > 0.8).

Abdominal Compartment Syndrome in Children: Clinical and Imaging Features.

OBJECTIVE: The objective of our study was to identify the clinical features and imaging findings of abdominal compartment syndrome (ACS) in children. MATERIALS AND METHODS: During the study period, ACS was diagnosed in 50 children, 14 of whom underwent CT or MRI. We reviewed the medical records of the 50 children to obtain clinical information, such as underlying risk factors, therapeutic approach, and clinical outcome, and we evaluated the CT and MRI examinations of the 14 children. We compared the imaging features of the 14 children with ACS with those of 14 age-matched control subjects who had abdominal distention without ACS. RESULTS: The most common risk factor of pediatric ACS was increased abdominal contents, particularly bowel dilatation. Among the 50 children, 38 underwent decompressive intervention. The mortality rate was 45% in the group who underwent decompression versus 58% in the group who did not undergo decompression intervention. From a review of the CT and MR images of the 14 patients with these examinations, we found that the most common findings were ascites (86%), basal lung atelectasis (69%), inferior vena cava (IVC) compression (50%), and abnormal enhancement of bowel wall (64%). Compared with the control subjects, the study group with ACS had the following suggestive imaging features: IVC compression (p = 0.001), basal lung atelectasis (p = 0.006), heterogeneous perfusion of the kidneys (p = 0.026), ascites (p = 0.043), and subcutaneous edema (p = 0.053). However, the ratio of maximal anteroposterior-to-transverse abdominal diameter (AT ratio) was not significant (p = 0.565). CONCLUSION: A well-known CT finding for ACS, an increased AT ratio, proved not specific for ACS in pediatric patients; rather, IVC compression, basal lung atelectasis, compromised renal perfusion, and ascites should raise suspicion for ACS in children.

Interventional Management of Subcapsular Hepatic Hematoma with Hepatic Compartment Syndrome After Laparoscopic Adrenalectomy.

Hepatic compartment syndrome is an increase in intrahepatic pressure sufficient to cause compromised hepatic perfusion. Early recognition and prompt management are essential for preventing catastrophic consequences including ischemic liver failure and hypovolemic shock. This is the rare case of laparoscopic adrenalectomy resulting in subcapsular hepatic hematoma with hepatic compartment syndrome. Contrast-enhanced computed tomography demonstrated extensive subcapsular hepatic hematoma with collapse of portal vein and inferior vena cava suggesting impending compartment syndrome. Diagnostical catheter angiography of the liver revealed innumerable foci of petechial extravasation from disrupted isolated arteries. Emergent percutaneous catheter decompression and transarterial embolization were successful.

Abdominal compartment syndrome secondary to megarectum and megasigmoid.

A 31-year-old male patient with chronic constipation of unknown aetiology presented emergently with worsening nausea, vomiting and abdominal distension of one week duration. On examination, his abdomen was distended with minimal tenderness. A plain film of the abdomen demonstrated severe faecal loading. The patient was haemodynamically unstable on admission and appeared sick. An urgent CT abdomen and pelvis was conducted showing extensive rectal dilatation and associated proximal colonic stercoral perforation. The patient proceeded straight to theatre for laparotomy as his general condition was deteriorating rapidly. On transfer to the operating table, the patient suffered cardiopulmonary arrest. Resuscitation was immediately commenced. Abdominal compartment syndrome was suspected. Cardiac output was re-established following a midline laparotomy which acted relieve the abdominal pressure. The rectosigmoid faecal content was decompressed via an enterotomy. The perforated segment of transverse colon was resected and an end colostomy fashioned. A year later, the continuity of the bowel was re-established.