Incidence, diagnosis, management and outcome of acute mesenteric ischaemia: a prospective, multicentre observational study (AMESI Study).

BACKGROUND: The aim of this multicentre prospective observational study was to identify the incidence, patient characteristics, diagnostic pathway, management and outcome of acute mesenteric ischaemia (AMI). METHODS: All adult patients with clinical suspicion of AMI admitted or transferred to 32 participating hospitals from 06.06.2022 to 05.04.2023 were included. Participants who were subsequently shown not to have AMI or had localized intestinal gangrene due to strangulating bowel obstruction had only baseline and outcome data collected. RESULTS: AMI occurred in 0.038% of adult admissions in participating acute care hospitals worldwide. From a total of 705 included patients, 418 patients had confirmed AMI. In 69% AMI was the primary reason for admission, while in 31% AMI occurred after having been admitted with another diagnosis. Median time from onset of symptoms to hospital admission in patients admitted due to AMI was 24 h (interquartile range 9-48h) and time from admission to diagnosis was 6h (1-12 h). Occlusive arterial AMI was diagnosed in 231 (55.3%), venous in 73 (17.5%), non-occlusive (NOMI) in 55 (13.2%), other type in 11 (2.6%) and the subtype could not be classified in 48 (11.5%) patients. Surgery was the initial management in 242 (58%) patients, of which 59 (24.4%) underwent revascularization. Endovascular revascularization alone was carried out in 54 (13%), conservative treatment in 76 (18%) and palliative care in 46 (11%) patients. From patients with occlusive arterial AMI, revascularization was undertaken in 104 (45%), with 40 (38%) of them in one site admitting selected patients. Overall in-hospital and 90-day mortality of AMI was 49% and 53.3%, respectively, and among subtypes was lowest for venous AMI (13.7% and 16.4%) and highest for NOMI (72.7% and 74.5%). There was a high variability between participating sites for most variables studied. CONCLUSIONS: The overall incidence of AMI and AMI subtypes varies worldwide, and case ascertainment is challenging. Pre-hospital delay in presentation was greater than delays after arriving at hospital. Surgery without revascularization was the most common management approach. Nearly half of the patients with AMI died during their index hospitalization. Together, these findings suggest a need for greater awareness of AMI, and better guidance in diagnosis and management. TRIAL REGISTRATION: NCT05218863 (registered 19.01.2022).

Diagnostic accuracy of biomarkers to detect acute mesenteric ischaemia in adult patients: a systematic review and meta-analysis.

BACKGROUND: Acute mesenteric ischaemia (AMI) is a disease with different pathophysiological mechanisms, leading to a life-threatening condition that is difficult to diagnose based solely on clinical signs. Despite widely acknowledged need for biomarkers in diagnosis of AMI, a broad systematic review on all studied biomarkers in different types of AMI is currently lacking. The aim of this study was to estimate the diagnostic accuracy of all potential biomarkers of AMI studied in humans. METHODS: A systematic literature search in PubMed, The Cochrane Library, Web of Science and Scopus was conducted in December 2022. Studies assessing potential biomarkers of AMI in (at least 10) adult patients and reporting their diagnostic accuracy were included. Meta-analyses of biomarkers' sensitivity, specificity, and positive and negative likelihood ratios were conducted. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed, and the study quality was assessed with the QUADAS-2 tool. RESULTS: Seventy-five studies including a total of 9914 patients assessed 18 different biomarkers in serum/plasma and one in urine (each reported in at least two studies), which were included in meta-analyses. None of the biomarkers reached a conclusive level for accurate prediction. The best predictive value overall (all studies with any type and stage of AMI pooled) was observed for Ischaemia-modified albumin (2 studies, sensitivity 94.7 and specificity 90.5), interleukin-6 (n = 4, 96.3 and 82.6), procalcitonin (n = 6, 80.1 and 86.7), and intestinal fatty acid-binding protein (I-FABP) measured in serum (n = 16, 73.9 and 90.5) or in urine (n = 4, 87.9 and 78.9). In assessment of transmural mesenteric ischaemia, urinary I-FABP (n = 2, 92.3 and 85.2) and D-dimer (n = 3, 87.6 and 83.6) showed moderate predictive value. Overall risk of bias was high, mainly because of selected study populations and unclear timings of the biomarker measurements after onset of symptoms. Combinations of biomarkers were rarely studied, not allowing meta-analyses. CONCLUSIONS: None of the studied biomarkers had sufficient sensitivity and specificity to diagnose AMI, although some biomarkers showed moderate predictive accuracy. Future studies should focus on timing of measurements of biomarkers, distinguishing between early stage and transmural necrosis, and between different types of AMI. Additionally, studies on combinations of biomarkers are warranted. PROSPERO registration: CRD42022379341.

Epidemiology of Acute Mesenteric Ischemia: A Population-Based Investigation.

BACKGROUND: There is a lack of population-based studies on acute mesenteric ischemia (AMI). We have therefore performed a nationwide epidemiological study in Estonia, addressing incidence, demographics, interventions and mortality of AMI. METHODS: A retrospective population-based review was conducted of all adult cases of AMI accrued from the digital Estonian Health Insurance Fund and Causes of Death Registry for 2016-2020 based on international classification of diseases (ICD-10) diagnostic codes and procedure codes (NOMESCO). RESULTS: Overall, 577 cases of AMI were identified-an annual incidence of 8.7 per 100,000. The median age was 79 (range 32-104) and 57% were female. Predominating comorbidities included hypertensive disease (81%), atherosclerosis (67%), and atrial fibrillation (52%). The majority of cases (60%) were caused by superior mesenteric artery occlusion (thrombosis 54%, embolism 12%, and unclear 34%). Inferior mesenteric artery occlusion occurred in 7%, non-occlusive mesenteric ischemia in 7%, venous thrombosis in 4%, whereas the type remained unclear in 21% of cases. 40% of patients received intervention (revascularization and/or intestinal resection) and 13% active non-operative treatment. In 21% an exploratory laparotomy or laparoscopy revealed unsalvageable bowel prompting end-of-life care, which was the only management in a further 25% of cases. CONCLUSIONS: The population-based annual incidence of AMI in Estonia was 8.7 per 100,000 during the study period. The overall hospital mortality and 1 year mortality were 64% and 74%, respectively. In the 53% of patients who received active treatment hospital mortality was 32% and 1 year all-cause mortality was 51%. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT04867499.

Incidence and outcomes of acute mesenteric ischaemia: a systematic review and meta-analysis.

OBJECTIVE: To estimate the incidence of acute mesenteric ischaemia (AMI), proportions of its different forms and short-term and long-term mortality. DESIGN: Systematic review and meta-analysis. DATA SOURCES: MEDLINE (Ovid), Web of Science, Scopus and Cochrane Library were searched until 26 July 2022. ELIGIBILITY CRITERIA: Studies reporting data on the incidence and outcomes of AMI in adult populations. DATA EXTRACTION AND SYNTHESIS: Data extraction and quality assessment with modified Newcastle-Ottawa scale were performed using predeveloped standard forms. The outcomes were the incidence of AMI and its different forms in the general population and in patients admitted to hospital, and the mortality of AMI in its different forms. RESULTS: From 3064 records, 335 full texts were reviewed and 163 included in the quantitative analysis. The mean incidence of AMI was 6.2 (95% CI 1.9 to 12.9) per 100 000 person years. On average 5.0 (95% CI 3.3 to 7.1) of 10 000 hospital admissions were due to AMI. Occlusive arterial AMI was the most common form constituting 68.6% (95% CI 63.7 to 73.2) of all AMI cases, with similar proportions of embolism and thrombosis.Overall short-term mortality (in-hospital or within 30 days) of AMI was 59.6% (95% CI 55.5 to 63.6), being 68.7% (95% CI 60.8 to 74.9) in patients treated before the year 2000 and 55.0% (95% CI 45.5 to 64.1) in patients treated from 2000 onwards (p<0.05). The mid/long-term mortality of AMI was 68.2% (95% CI 60.7 to 74.9). Mortality due to mesenteric venous thrombosis was 24.6% (95% CI 17.0 to 32.9) and of non-occlusive mesenteric ischaemia 58.4% (95% CI 48.6 to 67.7). The short-term mortality of revascularised occlusive arterial AMI was 33.9% (95% CI 30.7 to 37.4). CONCLUSIONS: In adult patients, AMI is a rarely diagnosed condition with high mortality, although with improvement of treatment results over the last decades. Two thirds of AMI cases are of occlusive arterial origin with potential for better survival if revascularised. PROSPERO REGISTRATION NUMBER: CRD42021247148.

Expanded measurements of intra-abdominal pressure do not increase the detection rate of intra-abdominal hypertension: a single-center observational study.

OBJECTIVE: Intra-abdominal hypertension may contribute to a poor outcome. Whether limiting intra-abdominal pressure measurements to preselected at-risk patients allows for sufficient detection of intra-abdominal hypertension is unclear. We aimed to clarify whether expanded intra-abdominal pressure monitoring results in an increased detection rate of intra-abdominal hypertension. DESIGN: Retrospective observational study. SETTING: General ICU of University Hospital. PATIENTS: Consecutive adult ICU patients from 2004 to 2011. INTERVENTIONS: Intra-abdominal pressure measurements in predefined at-risk patients. MEASUREMENTS AND MAIN RESULTS: Prospectively collected data of 2,696 admissions were divided into three subgroups according to the intra-abdominal pressure measurement policy in different years: 1) 2004-2005, mechanically ventilated patients with at least one additional risk factor for intra-abdominal hypertension (multiple trauma, abdominal surgery, pancreatitis, post-cardiopulmonary resuscitation, fluid resuscitation > 5 L/24 hr, vasoactive or inotropic support, and renal replacement therapy); 2) 2006-2009, all mechanically ventilated patients expected to stay for more than or equal to 24 hours; and 3) 2010-2011, mechanically ventilated patients with a body mass index greater than 30 kg/m, positive end-expiratory pressure more than 10 cm H2O, PaO2/FIO2 less than 300, use of vasopressors/inotropes, pancreatitis, hepatic failure/cirrhosis with ascites, gastrointestinal bleeding, or postlaparotomy. In all, 2,696 patients were studied, and 1,241 patients (46.0%) underwent intra-abdominal pressure monitoring. The intra-abdominal pressure was measured in 31.7%, 55.6%, and 41.1% of patients during the first, second, and third time periods (p < 0.001), and intra-abdominal hypertension (intra-abdominal pressure ≥ 12 mm Hg) occurred in 19.9%, 20.3%, and 20.1% of patients, respectively (p = 0.972). The mean intra-abdominal pressure at admission day was an independent predictor of mortality in patients with intra-abdominal pressure measurements started within the first 24 hours (odds ratio, 1.046 [95% CI, 1.019-1.072]). The mortality of patients with intra-abdominal hypertension was 29.8% versus 18.6% in those without intra-abdominal hypertension (p < 0.001). CONCLUSIONS: Expanding the measurement of intra-abdominal pressure to more than 50% of intensive care admissions does not increase the detection rate of intra-abdominal hypertension. In patients with intra-abdominal pressure monitoring, the mean intra-abdominal pressure on the admission day is an independent predictor of mortality.

Should we measure intra-abdominal pressures in every intensive care patient?

Intra-abdominal pressure (IAP) is seldom measured by default in intensive care patients. This review summarises the current evidence on the prevalence and risk factors of intra-abdominal hypertension (IAH) to assist the decision-making for IAP monitoring.IAH occurs in 20% to 40% of intensive care patients. High body mass index (BMI), abdominal surgery, liver dysfunction/ascites, hypotension/vasoactive therapy, respiratory failure and excessive fluid balance are risk factors of IAH in the general ICU population. IAP monitoring is strongly supported in mechanically ventilated patients with severe burns, severe trauma, severe acute pancreatitis, liver failure or ruptured aortic aneurysms. The risk of developing IAH is minimal in mechanically ventilated patients with positive end-expiratory pressure < 10 cmH2O, PaO2/FiO2 > 300, and BMI < 30 and without pancreatitis, hepatic failure/cirrhosis with ascites, gastrointestinal bleeding or laparotomy and the use of vasopressors/inotropes on admission. In these patients, omitting IAP measurements might be considered.In conclusions, clear guidelines to select the patients in whom IAP measurements should be performed cannot be given at present. In addition to IAP measurements in at-risk patients, a clinical assessment of the signs of IAH should be a part of every ICU patient's bedside evaluation, leading to prompt IAP monitoring in case of the slightest suspicion of IAH development.