Assessment of fluid unresponsiveness guided by lung ultrasound in abdominal surgery: a prospective cohort study.

A fluid challenge can generate an infraclinical interstitial syndrome that may be detected by the appearance of B-lines by lung ultrasound. Our objective was to evaluate the appearance of B-lines as a diagnostic marker of preload unresponsiveness and postoperative complications in the operating theater. We conducted a prospective, bicentric, observational study. Adult patients undergoing abdominal surgery were included. Stroke volume (SV) was determined before and after a fluid challenge with 250 mL crystalloids (Delta-SV) using esophageal Doppler monitoring. Responders were defined by an increase of Delta-SV > 10% after fluid challenge. B-lines were collected at four bilateral predefined zones (right and left anterior and lateral). Delta-B-line was defined as the number of newly appearing B-lines after a fluid challenge. Postoperative pulmonary complications were prospectively recorded according to European guidelines. In total, 197 patients were analyzed. After a first fluid challenge, 67% of patients were responders and 33% were non-responders. Delta-B-line was significantly higher in non-responders than responders [4 (2-7) vs 1 (0-3), p < 0.0001]. Delta-B-line was able to diagnose fluid non-responders with an area under the curve of 0.74 (95% CI 0.67-0.80, p < 0.0001). The best threshold was two B-lines with a sensitivity of 80% and a specificity of 57%. The final Delta-B-line could predict postoperative pulmonary complications with an area under the curve of 0.74 (95% CI 0.67-0.80, p = 0.0004). Delta-B-line of two or more detected in four lung ultrasound zones can be considered to be a marker of preload unresponsiveness after a fluid challenge in abdominal surgery.The objectives and procedures of the study were registered at Clinicaltrials.gov (NCT03502460; Principal investigator: Stéphane BAR, date of registration: April 18, 2018).

Epidemiology and prognosis of anti-infective therapy in the ICU setting during acute pancreatitis: a cohort study.

BACKGROUND: Recent international guidelines for acute pancreatitis (AP) recommend limiting anti-infective therapy (AIT) to cases of suspected necrotizing AP or nosocomial extrapancreatic infection. Limited data are available concerning empirical and documented AIT prescribing practices in patients admitted to the intensive care unit (ICU) for the management of AP. METHODS: Using a multicentre, retrospective (2009-2014), observational database of ICU patients admitted for AP, our primary objective was to assess the incidence of AIT prescribing practices during the first 30 days following admission. Secondary objectives were to assess the independent impact of centre characteristics on the incidence of AIT and to identify factors associated with crude hospital mortality in a logistic regression model. RESULTS: In this cohort of 860 patients, 359 (42%) received AIT on admission. Before day 30, 340/359 (95%) AIT patients and 226/501 (45%) AIT-free patients on admission received additional AIT, mainly for intra-abdominal and lung infections. A large heterogeneity was observed between centres in terms of the incidence of infections, therapeutic management including AIT and prognosis. Administration of AIT on admission or until day 30 was not associated with an increased mortality rate. Patients receiving AIT on admission had increased rates of complications (septic shock, intra-abdominal and pulmonary infections), therapeutic (surgical, percutaneous, endoscopic) interventions and increased length of ICU stay compared to AIT-free patients. Patients receiving delayed AIT after admission and until day 30 had increased rates of complications (respiratory distress syndrome, intra-abdominal and pulmonary infections), therapeutic interventions and increased length of ICU stay compared to those receiving AIT on admission. Risk factors for hospital mortality assessed on admission were age (adjusted odds ratio [95% confidence interval] 1.03 [1.02-1.05]; p < 0.0001), Balthazar score E (2.26 [1.43-3.56]; p < 0.0001), oliguria/anuria (2.18 [1.82-4.33]; p < 0.0001), vasoactive support (2.83 [1.73-4.62]; p < 0.0001) and mechanical ventilation (1.90 [1.15-3.14]; p = 0.011), but not AIT (0.63 [0.40-1.01]; p = 0.057). CONCLUSIONS: High proportions of ICU patients admitted for AP receive AIT, both on admission and during their ICU stay. A large heterogeneity was observed between centres in terms of incidence of infections, AIT prescribing practices, therapeutic management and outcome. AIT reflects the initial severity and complications of AP, but is not a risk factor for death.

The gray zone of the qualitative assessment of respiratory changes in inferior vena cava diameter in ICU patients.

INTRODUCTION: Transthoracic echocardiography (TTE) is a useful tool for minimally invasive hemodynamic monitoring in the ICU. Dynamic indices (such as the inferior vena cava distensibility index (dIVC)) can be used to predict fluid responsiveness in mechanically ventilated patients. Although quantitative use of the dIVC has been validated, the routinely used qualitative (visual) approach had not been assessed before the present study. METHODS: Qualitative and quantitative assessments of the dIVC were compared in a prospective, observational study. After operators with differing levels in critical care echocardiography had derived a qualitative dIVC, the last (expert) operator performed a standard, numeric measurement of the dIVC (referred to as the quantitative dIVC). Two groups of patients were separated into two groups: group (dIVC < 18%) and group (dIVC ≥ 18%). RESULTS: In total, 114 patients were assessed for inclusion, and 97 (63 men and 34 women) were included. The mean sensitivity and specificity values for qualitative assessment of the dIVC by an intensivist were 80.7% and 93.7%, respectively. A qualitative evaluation detected all quantitative dIVCs >40%. Most of the errors concerned quantitative dIVCs of between 15% and 30%. In the dIVC <18% group, two qualitative evaluation errors were noted for quantitative dIVCs of between 0 and 10%. The average of positive predictive values and negative predictive values for qualitative assessment of the dIVC by residents, intensivists and cardiologists were 83%, 83%, and 90%; and 92%, 94%, and 90%, respectively. The Fleiss kappa for all operators was estimated to be 0.68, corresponding to substantial agreement. CONCLUSION: The qualitative dIVC is a rather easy and reliable assessment for extreme numeric values. It has a gray zone between 15% and 30%. The highest and lowest limitations of the gray area are rather tedious to define. Despite reliability of the qualitative assessment when it comes to extreme to numerical values, the quantitative dIVC measurement must always be done within a hemodynamic assessment for intensive care patients. The qualitative approach can be easily integrated into a fast hemodynamic evaluation by using portable ultrasound scanner for out-of-hospital patients.