Assessment of Electrical Impedance Tomography to Set Optimal Positive End-Expiratory Pressure for Venoarterial Extracorporeal Membrane Oxygenation-Treated Patients.

OBJECTIVES: Patients on venoarterial extracorporeal membrane oxygenation have many risk factors for pulmonary complications in addition to their heart failure. Optimal positive end-expiratory pressure is unknown in these patients. The aim was to evaluate the ability of electrical impedance tomography to help the physician to select the optimal positive end-expiratory pressure in venoarterial extracorporeal membrane oxygenation treated and mechanically ventilated patients during a positive end-expiratory pressure trial. DESIGN: Observational prospective monocentric. SETTING: University hospital. PATIENTS: Patients (n = 23) older than 18 years old, on mechanical ventilation and venoarterial extracorporeal membrane oxygenation. INTERVENTIONS: A decreasing positive end-expiratory pressure trial (20-5 cm H2O) in increments of 5 cm H2O was performed and monitored by a collection of clinical parameters, ventilatory and ultrasonographic (cardiac and pulmonary) to define an optimal positive end-expiratory pressure according to respiratory criteria (optimal positive end-expiratory pressure selected by physician with respiratory parameters), and then adjusted according to hemodynamic and cardiac tolerances (optimal positive end-expiratory pressure selected by physician with respiratory, hemodynamic, and echocardiographic parameters). At the same time, electrical impedance tomography data (regional distribution of ventilation, compliance, and overdistension collapse) were recorded and analyzed retrospectively to define the optimal positive end-expiratory pressure. MEASUREMENTS AND MAIN RESULTS: The median of this optimal positive end-expiratory pressure was 10 cm H2O in our population. Electrical impedance tomography showed that increasing positive end-expiratory pressure promoted overdistention of ventral lung, maximum at positive end-expiratory pressure 20 cm H20 (34% [interquartile range, 24.5-40]). Decreasing positive end-expiratory pressure resulted in collapse of dorsal lung (29% [interquartile range, 21-45.8]). The optimal positive end-expiratory pressure selected by physician with respiratory parameters was not different from the positive end-expiratory pressure chosen by the electrical impedance tomography. However, there is a negative impact of a high level of intrathoracic pressure on hemodynamic and cardiac tolerances. CONCLUSIONS: Our results support that electrical impedance tomography appears predictive to define optimal positive end-expiratory pressure on venoarterial extracorporeal membrane oxygenation, aided by echocardiography to optimize hemodynamic assessment and management.

Prevalence of malnutrition in coronavirus disease 19: the NUTRICOV study.

Recent European Society of Parenteral and Enteral Nutrition guidelines highlighted the interest of prevention, diagnosis and treatment of malnutrition in the management of coronavirus disease 19 (COVID-19) patients. The aim of our study was to evaluate the prevalence of malnutrition in patients hospitalised for COVID-19. In a prospective observational cohort study malnutrition was diagnosed according to the Global Leadership Initiative on Malnutrition (GLIM) two-step approach. Patients were divided into two groups according to the diagnosis of malnutrition. Covariate selection for the multivariate analysis was based on P <0·2 in univariate analysis, with a logistic regression model and a backward elimination procedure. A partitioning of the population was realised. Eighty patients were prospectively enrolled. Thirty patients (37·5 %) had criteria for malnutrition. The need for intensive care unit admission (n 46, 57·5 %) was similar in the two groups. Three patients who died (3·75 %) were malnourished. Multivariate analysis exhibited that low BMI (OR 0·83, 95 % CI 0·73, 0·96, P = 0·0083), dyslipidaemia (OR 29·45, 95 % CI 3·12, 277·73, P = 0·0031), oral intake reduction <50 % (OR 3·169, 95 % CI 1·04, 9·64, P = 0·0422) and glomerular filtration rate (Chronic Kidney Disease Epidemiology Collaboration; CKD-EPI) at admission (OR 0·979, 95 % CI 0·96, 0·998, P = 0·0297) were associated with the occurrence of malnutrition. We demonstrate the existence of a high prevalence of malnutrition in a general cohort of COVID-19 inpatients according to GLIM criteria. Nutritional support in COVID-19 care seems an essential element.

Functional and Structural Integrity of Frontoparietal Connectivity in Traumatic and Anoxic Coma.

OBJECTIVES: Recovery from coma might critically depend on the structural and functional integrity of frontoparietal networks. We aimed to measure this integrity in traumatic brain injury and anoxo-ischemic (cardiac arrest) coma patients by using an original multimodal MRI protocol. DESIGN: Prospective cohort study. SETTING: Three Intensive Critical Care Units affiliated to the University in Toulouse (France). PATIENTS: We longitudinally recruited 43 coma patients (Glasgow Coma Scale at the admission < 8; 29 cardiac arrest and 14 traumatic brain injury) and 34 age-matched healthy volunteers. Exclusion criteria were disorders of consciousness lasting more than 30 days and focal brain damage within the explored brain regions. Patient assessments were conducted at least 2 days (5 ± 2 d) after complete withdrawal of sedation. All patients were followed up (Coma Recovery Scale-Revised) 3 months after acute brain injury. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Functional and structural MRI data were recorded, and the analysis was targeted on the posteromedial cortex, the medial prefrontal cortex, and the cingulum. Univariate analyses and machine learning techniques were used to assess diagnostic and predictive values. Coma patients displayed significantly lower medial prefrontal cortex-posteromedial cortex functional connectivity (area under the curve, 0.94; 95% CI, 0.93-0.95). Cardiac arrest patients showed specific structural disturbances within posteromedial cortex. Significant cingulum architectural disturbances were observed in traumatic brain injury patients. The machine learning medial prefrontal cortex-posteromedial cortex multimodal classifier had a significant predictive value (area under the curve, 0.96; 95% CI, 0.95-0.97), best combination of subregions that discriminates a binary outcome based on Coma Recovery Scale-Revised). CONCLUSIONS: This exploratory study suggests that frontoparietal functional disconnections are specifically observed in coma and their structural counterpart provides information about brain injury mechanisms. Multimodal MRI biomarkers of frontoparietal disconnection predict 3-month outcome in our sample. These findings suggest that fronto-parietal disconnection might be particularly relevant for coma outcome prediction and could inspire innovative precision medicine approaches.

Risk factor analysis for linezolid-associated thrombocytopenia in critically ill patients.

Linezolid is an antibiotic used against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus. Its primary adverse effect is haematotoxicity. The objective of this study was to analyse the risk factors for onset of thrombocytopenia in critically ill patients treated with linezolid. This was a retrospective, single-centre study of 72 patients. Platelets were measured from D0 to D20 after the start of treatment. The risk factors for thrombocytopenia were identified using a multivariate logistic regression analysis following a Monte Carlo simulation. Following ROC curve analysis, a baseline platelet count lower than 108 × 109/L and a Cmin higher than 4 mg/L, with respective odds ratios of 117 (95% CI [97-206]) and 3 (95% CI [1.5-6.2]) in the simulated population, were identified as risk factors. Among the source population patients combining these 2 factors, a significantly higher number developed thrombocytopenia (66.7% vs. 33.3%, p = 0.0042). A baseline platelet count lower than 108 × 109/L and a Cmin higher than 4 mg/L are risk factors for the onset of thrombocytopenia in critically ill patients treated with linezolid.

Cerebral Venous Thrombosis and Subdural Collection in a Comatose Patient: Do Not Forget Intracranial Hypotension. A Case Report.

BACKGROUND: The typical sign of intracranial hypotension (IH) is postural headache. However, IH can be associated with a large diversity of clinical or radiological signs leading to difficult diagnosis especially in case of coma. The association of cerebral venous thrombosis (CVT) and subdural hemorrhage is rare but should suggest the diagnosis of IH. METHODS: Case report. CASE DESCRIPTION: We report here a case of comatose patient due to spontaneous IH complicated by CVT and subdural hemorrhage. The correct diagnosis was delayed due to many confounding factors. IH was suspected after subdural hemorrhage recurrence and confirmed by magnetic resonance imaging (MRI). After 2 epidural patches with colloid, favorable outcome was observed. DISCUSSION: The most common presentation of IH is postural orthostatic headaches. In the present case report, the major clinical signs were worsening of consciousness and coma, which are a rare presentation. Diagnosis of IH is based on the association of clinical history, evocative symptomatology, and cerebral imaging. CVT occurs in 1-2% of IH cases and the association between IH, CVT, and subdural hemorrhage is rare. MRI is probably the key imaging examination. In the present case, epidural patch was performed after confounding factors for coma had been treated. Benefit of anticoagulation had to be balanced in this case with potential hemorrhagic complications, especially within the brain. CONCLUSION: Association of CVT and subdural hemorrhage should lead to suspect IH. Brain imaging can help and find specific signs of IH.

Outcome of community- versus hospital-acquired intra-abdominal infections in intensive care unit: a retrospective study.

BACKGROUND: To compare patients hospitalised in the intensive care unit (ICU) after surgery for community-acquired intra-abdominal infection (CA-IAI) and hospital-acquired intra-abdominal infection (HA-IAI) in terms of mortality, severity and complications. METHODS: Retrospective study including all patients admitted to 2 ICUs within 48 h of undergoing surgery for peritonitis. RESULTS: Two hundred twenty-six patients were enrolled during the study period. Patients with CA-IAI had an increased 28-day mortality rate compared to those with HA-IAI (30% vs 15%, respectively (p = 0.009)). At 90 days, the mortality rates were 36.7 and 37.5% in the CA-IAI group and HA-IAI group, respectively, with a similar APACHE II score on admission (median: 21 [15-25] vs. 21 [15-24] respectively, p = 0.63). The patients with HA-IAI had prolonged ICU and hospital stays (median: 17 [7-36] vs. 6[3-12] days, p < 0.001 and 41 [24-66] vs. 17 [7-32] days, p = 0.001), and experienced more complications (reoperation and reintubation) than those with CA-IAI. CONCLUSION: CA-IAI group had higher 28-day mortality rate than HA-IAI group. Mortality was similar at 90 days but those with HA-IAI had a prolonged ICU and hospital stay. In addition, they developed more complications.

Improving Provision of Preanesthetic Information Through Use of the Digital Conversational Agent "MyAnesth": Prospective Observational Trial.

BACKGROUND: Due to time limitations, the preanesthetic consultation (PAC) is not the best time for patients to integrate information specific to their perioperative care pathway. OBJECTIVE: The main objectives of this study were to evaluate the effectiveness of a digital companion on patients' knowledge of anesthesia and their satisfaction after real-life implementation. METHODS: We conducted a prospective, monocentric, comparative study using a before-and-after design. In phase 1, a 9-item self-reported anesthesia knowledge test (Delphi method) was administered to patients before and after their PAC (control group: PAC group). In phase 2, the study was repeated immediately after the implementation of a digital conversational agent, MyAnesth (@+PAC group). Patients' satisfaction and their representations for anesthesia were also assessed using a Likert scale and the Abric method of hierarchized evocation. RESULTS: A total of 600 tests were distributed; 205 patients and 98 patients were included in the PAC group and @+PAC group, respectively. Demographic characteristics and mean scores on the 9-point preinformation test (PAC group: 4.2 points, 95% CI 3.9-4.4; @+PAC: 4.3 points, 95% CI 4-4.7; P=.37) were similar in the two groups. The mean score after receiving information was better in the @+PAC group than in the PAC group (6.1 points, 95% CI 5.8-6.4 points versus 5.2 points, 95% CI 5.0-5.4 points, respectively; P<.001), with an added value of 0.7 points (95% CI 0.3-1.1; P<.001). Among the respondents in the @+PAC group, 82% found the information to be clear and appropriate, and 74% found it easily accessible. Before receiving information, the central core of patients' representations for anesthesia was focused on the fear of being put to sleep and thereafter on caregiver skills and comfort. CONCLUSIONS: The implementation of our digital conversational agent in addition to the PAC improved patients' knowledge about their perioperative care pathway. This innovative audiovisual support seemed clear, adapted, easily accessible, and reassuring. Future studies should focus on adapting both the content and delivery of a digital conversational agent for the PAC in order to maximize its benefit to patients.

Topological disintegration of resting state functional connectomes in coma.

Graph theory has been playing an increasingly important role in understanding the organizational properties of brain networks, subsequently providing new tools for the search of neural correlates of consciousness, particularly in the context of patients recovering from severe brain injury. However, this approach is not without challenges, as it usually relies on arbitrarily fixing a threshold in order to retain the strongest connections proportionally equal across subjects. This method increases the comparability between individuals or groups but it risks the inclusion of false positive and therefore spurious connections, especially in the context of brain disorders. Resting state data acquired in 25 coma patients and 22 healthy subjects was compared. We obtained a representative fixed density of significant connections by first applying a p-value-based threshold on healthy subjects' networks and then choosing a threshold at which all individuals exhibited meaningful connections. The obtained threshold (i.e. 10%) was used to construct graphs in the patient group. The findings showed that coma patients have lower number of significant connections with approximately 50% of them not fulfilling the criteria of the fixed density threshold. The remaining patients with relatively preserved global functional connectivity had sufficient significant connections between regions, but showed signs of major whole-brain network reorganization. These results warrant careful consideration in the construction of functional connectomes in patients with disorders of consciousness and set the scene for future studies investigating potential clinical implications of such an approach.

Risk factors for acquisition of carbapenem-resistance during treatment with carbapenem in the intensive care unit: a prospective study.

The emergence of carbapenemases in gram-negative aerobes is worrying. The aim of this prospective study was to estimate the incidence of acquisition of carbapenem-resistance during treatment in ICU and to identify the risk factors. This was a prospective, observational, cohort study. This study was conducted at intensive care unit, academic medical center, Toulouse Rangueil University Hospital. Patients were included if they received antibiotic treatment with carbapenem for more than 48 h. Biological samples were taken in accordance with current practice in the unit. The main endpoint was the occurrence of bacterial resistance to carbapenems occurring between the onset of treatment and the patient's exit from the ICU. Uni- and multi-variate analyses were carried out. Of the 364 patients admitted to the unit between May and November 2014, 78 were included in our study and 16 (20.51%) developed resistance. The two main risk factors were a length of stay in ICU of more than 29 days (HR = 3.61, p = 0.01) and the presence of Pseudomonas aeruginosa in the samples taken before the start of treatment (HR = 5.31, p = 0.002). No resistance due to carbapenemase production was observed in this study. The prescription of carbapenems in the ICU setting must adhere to the expert guidelines. In light of our results, special attention must be paid to patients whose stay in intensive care is prolonged, and those in whom Pseudomonas aeruginosa is isolated from bacteriological samples taken before the beginning of antibiotic therapy.

Brain Gray Matter MRI Morphometry for Neuroprognostication After Cardiac Arrest.

OBJECTIVES: We hypothesize that the combined use of MRI cortical thickness measurement and subcortical gray matter volumetry could provide an early and accurate in vivo assessment of the structural impact of cardiac arrest and therefore could be used for long-term neuroprognostication in this setting. DESIGN: Prospective cohort study. SETTING: Five Intensive Critical Care Units affiliated to the University in Toulouse (France), Paris (France), Clermont-Ferrand (France), Liège (Belgium), and Monza (Italy). PATIENTS: High-resolution anatomical T1-weighted images were acquired in 126 anoxic coma patients ("learning" sample) 16 ± 8 days after cardiac arrest and 70 matched controls. An additional sample of 18 anoxic coma patients, recruited in Toulouse, was used to test predictive model generalization ("test" sample). All patients were followed up 1 year after cardiac arrest. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Cortical thickness was computed on the whole cortical ribbon, and deep gray matter volumetry was performed after automatic segmentation. Brain morphometric data were employed to create multivariate predictive models using learning machine techniques. Patients displayed significantly extensive cortical and subcortical brain volumes atrophy compared with controls. The accuracy of a predictive classifier, encompassing cortical and subcortical components, has a significant discriminative power (learning area under the curve = 0.87; test area under the curve = 0.96). The anatomical regions which volume changes were significantly related to patient's outcome were frontal cortex, posterior cingulate cortex, thalamus, putamen, pallidum, caudate, hippocampus, and brain stem. CONCLUSIONS: These findings are consistent with the hypothesis of pathologic disruption of a striatopallidal-thalamo-cortical mesocircuit induced by cardiac arrest and pave the way for the use of combined brain quantitative morphometry in this setting.

Combined Thoracic Ultrasound Assessment during a Successful Weaning Trial Predicts Postextubation Distress.

BACKGROUND: Recent studies suggest that isolated sonographic assessment of the respiratory, cardiac, or neuromuscular functions in mechanically ventilated patients may assist in identifying patients at risk of postextubation distress. The aim of the present study was to prospectively investigate the value of an integrated thoracic ultrasound evaluation, encompassing bedside respiratory, cardiac, and diaphragm sonographic data in predicting postextubation distress. METHODS: Longitudinal ultrasound data from 136 patients who were extubated after passing a trial of pressure support ventilation were measured immediately after the start and at the end of this trial. In case of postextubation distress (31 of 136 patients), an additional combined ultrasound assessment was performed while the patient was still in acute respiratory failure. We applied machine-learning methods to improve the accuracy of the related predictive assessments. RESULTS: Overall, integrated thoracic ultrasound models accurately predict postextubation distress when applied to thoracic ultrasound data immediately recorded before the start and at the end of the trial of pressure support ventilation (learning sample area under the curve: start, 0.921; end, 0.951; test sample area under the curve: start, 0.972; end, 0.920). Among integrated thoracic ultrasound data, the recognition of lung interstitial edema and the increased telediastolic left ventricular pressure were the most relevant predictive factors. In addition, the use of thoracic ultrasound appeared to be highly accurate in identifying the causes of postextubation distress. CONCLUSIONS: The decision to attempt extubation could be significantly assisted by an integrative, dynamic, and fully bedside ultrasonographic assessment of cardiac, lung, and diaphragm functions.

Training in intraoperative handover and display of a checklist improve communication during transfer of care: An interventional cohort study of anaesthesia residents and nurse anaesthetists.

BACKGROUND: Handovers during anaesthesia are common, and failures in communication may lead to morbidity and mortality. OBJECTIVES: We hypothesised that intraoperative handover training and display of a checklist would improve communication during anaesthesia care transition in the operating room. DESIGN: Interventional cohort study. SETTING: Single-centre tertiary care university hospital. PARTICIPANTS: A total of 204 random observations of handovers between anaesthesia providers (residents and nurse anaesthetists) over a 6-month period in 2016. INTERVENTION: Two geographically different hospital sites were studied simultaneously (same observations, but no training/checklist at the control site): first a 2-week 'baseline' observation period; then handover training and display of checklists in each operating room (at the intervention site only) followed by an 'immediate' second and finally a third (3 months later) observation period. MAIN OUTCOME MEASURES: A 22-item checklist was created by a modified DELPHI method and a checklist score calculated for each handover by adding the individual scores for each item as follows: -1, if error in communicating item; 0, unreported item; 0.5, if partly communicated item; 1, if correctly communicated item. RESULTS: Before training and display of the checklist, the scores in the interventional and the control groups were similar. There was no improvement in the control group's scores over the three observation periods. In the interventional group, the mean (95% confidence interval) score increased by 43% [baseline 7.6 (6.7 to 8.4) n = 42; 'immediate' 10.9 (9.4 to 12.4) n = 27, P < 0.001]. This improvement persisted at 3 months without an increase in the mean duration of handovers. CONCLUSION: Intraoperative handover training and display of a checklist in the operating room improved the checklist score for intraoperative transfer of care in anaesthesia.

Early Prediction of 3-month Survival of Patients in Refractory Cardiogenic Shock and Cardiac Arrest on Extracorporeal Life Support.

BACKGROUND: Extracorporeal life support (ECLS) holds the promise of significant improvement of the survival of patient in refractory cardiogenic shock (CS) or cardiac arrest (CA). Nevertheless, it remains to be shown to which extent these highly invasive supportive techniques could improve long-term patient's outcome. METHODS: The outcomes of 82 adult ECLS patients at our institution between January 2012 and December 2013 were retrospectively analyzed. RESULTS: Patients were essentially men (64.7%) and are 54 years old. Preexisting ischemic (53.7%) and dilated cardiomyopathy (14.6%) were frequent. ECLS indications were shared equally between CA and CS. ECLS-specific adverse effects as hemorrhage (30%) and infection (50%) were frequent. ECLS was effective for 43 patients (54%) with recovery for 35 (43%), 5 (6%) heart transplant, and 3 (4%) left ventricular assist device support. Mortality rate at 30 days was 59.8%, but long-term and 3-month survival rates were similar of 31.7%. Initial plasma lactate levels >5.3 mmol/L and glomerular filtration rate <43 ml/min/1.73 m2 were significantly associated with 3-month mortality (risk ratio [RR] 2.58 [1.21-5.48]; P = 0.014; RR 2.10 [1.1-4]; P = 0.024, respectively). Long-term follow-up had shown patients paucisymptomatic (64% New York Heart Association 1-2) and autonomic (activities of daily living [ADL] score 6 ± 1.5). CONCLUSION: In case of refractory CA or CS, lactates and renal function at ECLS initiation could serve as outcome predictor for risk stratification and ECLS indication.

Beneficial effects of levobupivacaine regional anaesthesia on postoperative opioid induced hyperalgesia in diabetic mice.

BACKGROUND: Diabetic neuropathy is one of the most common complications of diabetes and causes various problems in daily life. The aim of this study was to assess the effect of regional anaesthesia on post surgery opioid induced hyperalgesia in diabetic and non-diabetic mice. METHODS: Diabetic and non-diabetic mice underwent plantar surgery. Levobupivacaine and sufentanil were used before surgery, for sciatic nerve block (regional anaesthesia) and analgesia, respectively. Diabetic and non-diabetic groups were each randomly assigned to three subgroups: control, no sufentanil and no levobupivacaine; sufentanil and no levobupivacaine; sufentanil and levobupivacaine. Three tests were used to assess pain behaviour: mechanical nociception; thermal nociception and guarding behaviours using a pain scale. RESULTS: Sufentanil, alone or in combination with levobupivacaine, produced antinociceptive effects shortly after administration. Subsequently, sufentanil induced hyperalgesia in diabetic and non-diabetic mice. Opioid-induced hyperalgesia was enhanced in diabetic mice. Levobupivacaine associated to sufentanil completely prevented hyperalgesia in both groups of mice. CONCLUSION: The results suggest that regional anaesthesia can decrease opioid-induced hyperalgesia in diabetic as well as in non-diabetic mice. These observations may be clinically relevant for the management of diabetic patients.

Patient-ventilator synchrony in Neurally Adjusted Ventilatory Assist (NAVA) and Pressure Support Ventilation (PSV): a prospective observational study.

BACKGROUND: Weaning from mechanical ventilation is associated with the presence of asynchronies between the patient and the ventilator. The main objective of the present study was to demonstrate a decrease in the total number of patient-ventilator asynchronies in invasively ventilated patients for whom difficulty in weaning is expected by comparing neurally adjusted ventilatory assist (NAVA) and pressure support ventilation (PSV) ventilatory modes. METHODS: We performed a prospective, non-randomized, non-interventional, single-center study. Thirty patients were included in the study. Each patient included in the study benefited in an unpredictable way from both modes of ventilation, NAVA or PSV. Patients were successively ventilated for 23 h in NAVA or in PSV, and then they were ventilated for another 23 h in the other mode. Demographic, biological and ventilatory data were collected during this period. The two modes of ventilatory support were compared using the non-parametric Wilcoxon test after checking for normal distribution by the Kolmogorov-Smirnov test. The groups were compared using the chi-square test. RESULTS: The median level of support was 12.5 cmH2O (4-20 cmH2O) in PSV and 0.8 cmH2O/µvolts (0.2-3 cmH2O/µvolts) in NAVA. The total number of asynchronies per minute in NAVA was lower than that in PSV (0.46 vs 1, p < 0.001). The asynchrony index was also reduced in NAVA compared with PSV (1.73 vs 3.36, p < 0.001). In NAVA, the percentage of ineffective efforts (0.77 vs 0.94, p = 0.036) and the percentage of auto-triggering were lower compared with PSV (0.19 vs 0.71, p = 0.038). However, there was a higher percentage of double triggering in NAVA compared with PSV (0.76 vs 0.71, p = 0.046). CONCLUSION: The total number of asynchronies in NAVA is lower than that in PSV. This finding reflects improved patient-ventilator interaction in NAVA compared with the PSV mode, which is consistent with previous studies. Our study is the first to analyze patient-ventilator asynchronies in NAVA and PSV on such an important duration. The decrease in the number of asynchronies in NAVA is due to reduced ineffective efforts and auto-triggering.

Doppler renal resistive index for early detection of acute kidney injury after major orthopaedic surgery: a prospective observational study.

BACKGROUND: Postoperative acute kidney injury (AKI) is a cause of morbidity and mortality. Its diagnosis requires better markers than variations in diuresis or postoperative serum creatinine. OBJECTIVES: The aim of this study was to evaluate the accuracy of Doppler renal resistive index for early detection of AKI after hip or knee arthroplasty. DESIGN: A prospective observational study. SETTING: A single-centre study in a university hospital. PATIENTS: Fifty men and women older than 65 years, requiring hip or knee replacement with at least two perioperative AKI risk factors, including diabetes, arteritis, chronic heart or renal dysfunction, and prescription of angiotensin-converting enzyme (ACE) inhibitors. Exclusion criteria were poor abdominal echogenicity, arrhythmia, respiratory failure or agitation. INTERVENTION: Renal resistive index was measured preoperatively and in the postanaesthesia care unit. RESULTS: Sixteen patients presented with AKI in the postoperative period. Resistive index was increased in this group in both the preoperative [0.72 (0.69 to 0.73) vs. 0.66 (0.58 to 0.71); P = 0.01] and postoperative periods [0.75 (0.71 to 0.75) vs. 0.67 (0.62 to 0.72); P = 0.0001]. Resistive index evaluated by ROC curves and AUC to detect AKI was 0.862 [95% confidence interval (95% CI) 0.735 to 0.943]. The most accurate cut-off value was a postoperative resistive index of 0.705 (sensitivity = 94%, specificity = 71%, LR+ = 3.19 and LR- = 0.09). The grey area between 0.705 and 0.73, corresponding to the inconclusive zone, included 26% (13/50) of all the patients. CONCLUSION: Postoperative resistive index appears to be effective for early detection of AKI after major orthopaedic surgery. Resistive index can be measured in the postoperative care unit in patients at risk of AKI. TRIAL REGISTRATION NUMBER: 29-0512.

Assessment of brain midline shift using sonography in neurosurgical ICU patients.

INTRODUCTION: Brain midline shift (MLS) is a life-threatening condition that requires urgent diagnosis and treatment. We aimed to validate bedside assessment of MLS with Transcranial Sonography (TCS) in neurosurgical ICU patients by comparing it to CT. METHODS: In this prospective single centre study, patients who underwent a head CT were included and a concomitant TCS performed. TCS MLS was determined by measuring the difference between the distance from skull to the third ventricle on both sides, using a 2 to 4 MHz probe through the temporal window. CT MLS was measured as the difference between the ideal midline and the septum pellucidum. A significant MLS was defined on head CT as > 0.5 cm. RESULTS: A total of 52 neurosurgical ICU patients were included. The MLS (mean ± SD) was 0.32 ± 0.36 cm using TCS and 0.47 ± 0.67 cm using CT. The Pearson's correlation coefficient (r(2)) between TCS and CT scan was 0.65 (P < 0.001). The bias was 0.09 cm and the limits of agreements were 1.10 and -0.92 cm. The area under the ROC curve for detecting a significant MLS with TCS was 0.86 (95% CI = 0.74 to 0.94), and, using 0.35 cm as a cut-off, the sensitivity was 84.2%, the specificity 84.8% and the positive likelihood ratio was 5.56. CONCLUSIONS: This study suggests that TCS could detect MLS with reasonable accuracy in neurosurgical ICU patients and that it could serve as a bedside tool to facilitate early diagnosis and treatment for patients with a significant intracranial mass effect.

Predicting preload responsiveness using simultaneous recordings of inferior and superior vena cavae diameters.

INTRODUCTION: Echocardiographic indices based on respiratory variations of superior and inferior vena cavae diameters (ΔSVC and ΔIVC, respectively) have been proposed as predictors of fluid responsiveness in mechanically ventilated patients, but they have never been compared simultaneously in the same patient sample. The aim of this study was to compare the predictive value of these echocardiographic indices when concomitantly recorded in mechanically ventilated septic patients. METHODS: Septic shock patients requiring hemodynamic monitoring were prospectively enrolled over a 1-year period in a mixed medical surgical ICU of a university teaching hospital (Toulouse, France). All patients were mechanically ventilated. Predictive indices were obtained by transesophageal and transthoracic echocardiography and were calculated as follows: (Dmax - Dmin)/Dmax for ΔSVC and (Dmax - Dmin)/Dmin for ΔIVC, where Dmax and Dmin are the maximal and minimal diameters of SVC and IVC. Measurements were performed at baseline and after a 7-ml/kg volume expansion using a plasma expander. Patients were separated into responders (increase in cardiac index ≥15%) and nonresponders (increase in cardiac index <15%). RESULTS: Among 44 included patients, 26 (59%) patients were responders (R). ΔSVC was significantly more accurate than ΔIVC in predicting fluid responsiveness. The areas under the receiver operating characteristic curves for ΔSVC and ΔIVC regarding assessment of fluid responsiveness were significantly different (0.74 (95% confidence interval (CI): 0.59 to 0.88) and 0.43 (95% CI: 0.25 to 0.61), respectively (P = 0.012)). No significant correlation between ΔSVC and ΔIVC was found (r = 0.005, P = 0.98). The best threshold values for discriminating R from NR was 29% for ΔSVC, with 54% sensitivity and 89% specificity, and 21% for ΔIVC, with 38% sensitivity and 61% specificity. CONCLUSIONS: ΔSVC was better than ΔIVC in predicting fluid responsiveness in our cohort. It is worth noting that the sensitivity and specificity values of ΔSVC and ΔIVC for predicting fluid responsiveness were lower than those reported in the literature, highlighting the limits of using these indices in a heterogeneous sample of medical and surgical septic patients.