Catherine Fleureau

Impact of High Volume Hemofiltration on Hemodynamic Disturbance and Outcome during Septic Shock

The purpose of this study was to evaluate the effect of high volume continuous venovenous hemofiltration (HVCVVH) on hemodynamic and outcome in patients with septic shock. The primary end point was mortality at 28 days. Study design was a prospective case series, and study setting was a 12 bed intensive care unit at a university hospital. A total of 24 consecutive patients with septic shock were included, with dysfunction of more than two organs. All patients were treated by HVCVVH with ultrafiltration rate between 40 ml · kg−1 · hr−1 and 60 ml · kg−1 · hr−1 for 96 hours. In all patients, the increase in hemodynamic parameters was statistically significant (p < 0.05), with a significant linear decrease in norepinephrine doses (p < 0.05). The predicted 28 day mortality by three different severity scores was more than 70%, and the mortality in the hemofiltration group was 46% (p < 0.075). In the present study of septic shock patients with organ dysfunction, the hemodynamic parameters increased regularly during treatment by HVCVVH. This study suggests a beneficial effect of HVCVVH on 28 day mortality (46%vs. 70%), and further studies with larger cohorts are required.

Doppler resistive index to reflect regulation of renal vascular tone during sepsis and acute kidney injury

IntroductionRenal resistive index (RI), determined by Doppler ultrasonography, directly reveals and quantifies modifications in renal vascular resistance. The aim of this study was to evaluate if mean arterial pressure (MAP) is determinant of renal RI in septic, critically ill patients suffering or not from acute kidney injury (AKI).MethodsThis prospective observational study included 96 patients. AKI was defined according to RIFLE criteria and transient or persistent AKI according to renal recovery within 3 days.ResultsMedian renal RIs were 0.72 (0.68-0.75) in patients without AKI and 0.76 (0.72-0.80) in patients with AKI (P=0.001). RIs were 0.75 (0.72-0.79) in transient AKI and 0.77 (0.70-0.80) in persistent AKI (P=0.84). RI did not differ in patients given norepinephrine infusion and was not correlated with norepinephrine dose. RI was correlated with MAP (ρ= -0.47; P=0.002), PaO2/FiO2 ratio (ρ= -0.33; P=0.04) and age (ρ=0.35; P=0.015) only in patients without AKI.ConclusionsA poor correlation between renal RI and MAP, age, or PaO2/FiO2 ratio was found in septic and critically ill patients without AKI compared to patients with AKI. These findings suggest that determinants of RI are multiple. Renal circulatory response to sepsis estimated by Doppler ultrasonography cannot reliably be predicted simply from changes in systemic hemodynamics. As many factors influence its value, the interest in a single RI measurement at ICU admission to determine optimal MAP remains uncertain.

Precision of noninvasive hemoglobin-level measurement by pulse co-oximetry in patients admitted to intensive care units for severe gastrointestinal bleeds.

Objectives:Measurement of total hemoglobin, based on pulse co-oximetry, is a continuous and noninvasive method that has been principally evaluated in healthy volunteers subjected to hemodilution. We tested the hypothesis that its accuracy could adversely affect patients presenting with severe hemorrhage, which is traditionally associated with increased microvascular tone. Design:Observational study. Setting:Twelve-bed mixed medico-surgical intensive care unit. Patients:Thirty-three patients admitted to our critical care unit for gastrointestinal bleeds were included. Interventions:A spectrophotometric sensor was positioned on the patient’s fingertip and connected to a pulse co-oximeter. During the first 24 hrs following admission, venous hemoglobin level was determined at the laboratory every 8 hrs and was compared with hemoglobin levels displayed on the pulse co-oximeter measurements screen and/or measured from capillary blood using a portable photometer. Measurements and Main Results:The primary end point was the percentage of inaccurate measurements, which were defined as >15% difference compared with reference values or their unavailability for any technical reason. Twenty-five (19%) measurements of pulse co-oximeter measurements were unavailable from the screen. Pulse co-oximeter measurements and capillary hemoglobin levels were significantly correlated to venous hemoglobin level. For venous hemoglobin level compared with pulse co-oximeter measurements (n = 105), and for venous hemoglobin level compared with capillary hemoglobin levels (n = 111), the biases were, respectively, 1.0 ± 1.9 g dL−1 and 0.4 ± 1.0 g dL−1 (p < .05). The proportion of inaccurate measurements was significantly higher for pulse co-oximeter measurements (56% vs. 15%, p < .05). Although the use of norepinephrine did not affect concordance parameters, unavailability of measurements was frequently observed (42% vs. 15%, p < .05). Conclusions:Determination of pulse co-oximetry-based hemoglobin in patients presenting with severe gastrointestinal bleeds can be inaccurate, which renders its use to guide transfusion decisions potentially hazardous. The unavailability of measurements, especially during vasopressor infusion, represents another serious limitation for hemorrhagic patients.

Kinetic eGFR and Novel AKI Biomarkers to Predict Renal Recovery

BACKGROUND AND OBJECTIVES Prompt recognition of severe renal impairment could improve the early management of critically ill patients. We compared the value of kinetic eGFR, plasma neutrophil gelatinase-associated lipocalin (NGAL), and urine tissue inhibitor of metalloproteinase-2 and urine insulin-like growth factor-binding protein 7 ([TIMP-2]*[IGFBP7]) in predicting short-term recovery from AKI and major adverse kidney events. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS During the 6-month study period, 245 patients were admitted to our intensive care unit. This study included 57 consecutive patients presenting with AKI within the first 24 hours after admission. AKI markers were evaluated at inclusion (day 0) and 24 hours later (day 1). Kinetic eGFR was calculated on day 1 according to serum creatinine evolution. Renal recovery was defined as normalization of serum creatinine with reversal of oliguria within 48 hours. Major adverse kidney events included death, need for RRT, or persistence of renal dysfunction at hospital discharge. RESULTS Plasma NGAL and [TIMP-2]*[IGFBP7] predicted renal recovery, with area under the receiver-operating characteristic curve (AUC-ROC) values between 0.70 and 0.79 at inclusion. Although plasma NGAL values frequently reached the maximal measurement range, their decrease on day 1 predicted recovery. The kinetic eGFR calculation after initial resuscitation provided the best AUC-ROC value for renal recovery, at 0.87. The best predictions for major adverse kidney events were provided by [TIMP-2]*[IGFBP7] and kinetic eGFR (equal AUC-ROCs of 0.81). Combining AKI markers in addition to clinical prediction models improved the discrimination and reclassification of patients who will recover from AKI or suffer from major adverse kidney events. CONCLUSIONS Biomarkers of kidney damage predicted short-term renal recovery and major adverse kidney events for an unselected cohort of critically ill patients. Calculating the kinetic eGFR imposed a delay after initial resuscitation but provided a good diagnostic and prognostic approach. The utility of functional and damage AKI marker combinations in addition to clinical information requires validation in larger prospective studies.

Accuracy of determining hemoglobin level using occlusion spectroscopy in patients with severe gastrointestinal bleeding.

Background:In patients presenting with severe hemorrhage, the authors conducted an equivalence trial that compared noninvasive occlusion spectroscopy and the capillary blood method to determine hemoglobin level. Methods:This prospective observational study included patients admitted to their intensive care unit for gastrointestinal bleeding. A ring-shaped sensor, connected to a NBM-200MP (OrSense®, Nes Ziona, Israel), was fitted onto the patient’s thumb to intermittently measure hemoglobin (SotHb). During the first 24 h after admission, venous hemoglobin level, considered as the reference method, was determined at the laboratory every 8 h and was compared to SotHb and the capillary blood method. The primary endpoint was the proportion of inaccurate measurements, defined as greater than 15% difference compared with reference values or their unavailability for any technical reason. Results:The study was scheduled to include 68 patients but was stopped prematurely after an interim analysis of 34 patients. The proportion of inaccuracies revealed that SotHb could not be considered equivalent to the capillary blood method (47% [95% CI, 43–51] and 24% [95% CI, 20–28]). Considering venous hemoglobin level as a reference method, the mean biases for SotHb (n = 133) and the capillary blood method (n = 135) were, respectively, −0.4 ± 2.0 and 0.8 ± 1.2 g/dl (P < 0.05). SotHb was associated with an increased incidence of failed transfusion. The inaccuracy of SotHb tended to be increased in patients receiving vasopressor agents. Conclusions:Noninvasive determination of hemoglobin level based on occlusion spectroscopy lacks accuracy in patients presenting with severe gastrointestinal bleeding and cannot be considered equivalent to the capillary-based method. This inaccuracy seems to be moderately influenced by the infusion of vasopressor agents.

Acquired deficit of antithrombin and role of supplementation in septic patients during continuous veno-venous hemofiltration.

Continuous renal replacement therapy (CRRT) is widely used in the management of septic patients with acute renal failure (ARF). Short filter lifespan (<24 hours) is a major concern and may result of a procoagulating state. The aim of this study was to investigate the relationship between antithrombin (AT) deficit and early filter clotting, and whether supplementation of AT could increase filter lifespan. Two different methods for supplementation, bolus and continuous infusion were also compared. We conducted a two-center prospective study from March 2003 to May 2004. Twenty-seven patients with septic shock and ARF were included and treated by CRRT. Unfractionated heparin (UHF) was used for anticoagulation. The initial level of AT was low with a median level at 45.4% (16%–69%). Low AT activity was associated with shorter filter lifespan. Supplementation led to a longer filter lifespan (15.2–33.2 hours) (p < 0.05). Continuous infusion provided better results: 48.5 vs. 27.8 hours for bolus method. This study suggests that AT measurement should be considered in continuous veno-venous hemofiltration with clotting problems as supplementation could increase filter lifespan by more than 100%. Continuous infusion is preferable. Cost effectiveness should be evaluated shortly.

Diagnostic et prise en charge des ischémies mésentériques aiguës

The prevalence of significant splanchnic arterial stenoses is increasing, but remains mostly asymptomatic due to abundant collateral circulation. Acute insufficiency of mesenteric arterial blood flow accounts for 60 to 70% of cases of mesenteric ischemia and results mostly from a superior mesenteric embolus. Despite major advances have been achieved in understanding the pathogenic mechanisms of bowel ischemia, its prognosis remains dismal with mortality rates about 60%. The diagnosis of acute mesenteric ischemia depends upon a high clinical suspicion, especially in patients with known risk factors. Rapid diagnosis is essential to prevent intestinal infarction. However, early signs and symptoms of mesenteric ischemia are non specific, and definitive diagnosis often requires radiologic examinations. Early and liberal implementation of angiography has been the major advance over the past 30 years which allowed increasing diagnostic accuracy of acute mesenteric ischemia. CT and MR-based angiographic techniques have emerged as alternatives less invasive and more accurate to analyse splanchnic vessels and evaluate bowel infarction. The goal of treatment of patients with acute mesenteric ischemia is to restore intestinal oxygenation as quickly as possible after initial management that includes rapid hemodynamic monitoring and support. Surgery should not be delayed in patients suspected of having intestinal necrosis.

Effects of chest physiotherapy by expiratory flow increase on secretion removal and lung mechanics in ventilated patients: a randomized crossover study

Dear Editor, A recent study published in this journal evaluated the effects of manually assisting a cough using a strong expiratory manual compressive manoeuver in mechanically ventilated patients [1]. The authors showed significant removal of sputum with no effect on gas exchange or lung mechanics. However, the benefits and safety of chest physiotherapy in ICUs remain controversial, especially when there is diffuse alveolar damage [2]. We proposed in this crossover study conducted at the Bordeaux University Hospital (France) to assess the effects of another physiotherapy technique to assist mechanically ventilated patients. After approval from our ethics committee (Comité de Protection des Personnes Sud-Ouest et Outre Mer III, Agreement number DC 2012/114), 16 consecutive patients presenting a ventilator-associated pneumonia and requiring a neuromuscular blockade were prospectively included between March 2013 and January 2014. Non-inclusion criteria were hemodynamic instability and chest trauma. All treatments were left to the discretion of the attending physicians according to international recommendations. The expiratory flow increase (EFI) technique consisted of prolonged slow manual chest and abdomen compressions throughout an entire expiration phase. Patients were randomly divided into two groups: a group receiving an endotracheal suction (ETS) followed, 4 h later, by a respiratory physiotherapy session concluded by an ETS (EFI + ETS) and the other group receiving first the EFI + ETS, followed 4 h later by ETS alone (Fig. S1). Respiratory mechanics were continuously recorded using SERVO-i RCR v3.7 software (Maquet Critical Care, Solna, Sweden); measurements were the average of all respiratory cycles during 1 min before treatment (t0), immediately after treatment (t1), 20 min later (t2), and 1 h later (t3). The first minute of all physiotherapy sessions was also recorded. The weight of bronchial secretions was measured at t1 for each group. The demographic characteristics of included patients are shown in Table S1. There was a significant decrease in peak pressure and plateau pressure during and immediately after the EFI sessions (Fig. 1). The amount of secretions collected was significantly increased after EFI + ETS as compared to ETS alone (120 [40–255] vs 210 [80–545] mg, P = 0.02). A transient improvement in static lung compliance was also observed at t1 and t2 after EFI + ETS (Table S2). The rational of chest physiotherapy is to displace secretions from the peripheral to the more central airways, where they can be removed. However, the literature is conflicting regarding the benefits of mobilizing peripheral secretions by rapidly squeezing air out using prolonged strong compressions (manually assisted cough), by brief strong manual expiratory compressions (hard manual ribcage compressions), or by using prolonged *Correspondence: antoine.dewitte@chu‐bordeaux.fr 2 CHU de Bordeaux, Service d’Anesthésie‐Réanimation II, 33000 Bordeaux, France Full author information is available at the end of the article

Benefits of intraoperative analgesia guided by the Analgesia Nociception Index (ANI) in bariatric surgery: An unmatched case-control study

INTRODUCTION Analgesia Nociception Index (ANI) has been proposed for the evaluation of the nociception-antinociception balance in the perioperative period. In obese patients, where the management of analgesia may be rendered difficult by pharmacological changes, we hypothesised that the monitoring of analgesia with ANI would reduce intraoperative opioid consumption during bariatric surgery. METHODS This monocentric, observational, unmatched case-control study aimed to compare perioperative data from obese subjects (body mass index ≥35kgm-2) during bariatric surgery with or without the use of ANI monitoring (ANI+ group versus ANI- group). Intraoperative analgesia was provided by injection of sufentanil, which was performed according to the clinicians assessment in the ANI- group or to the ANI value in the ANI+ group. The primary outcome was the mean hourly intraoperative sufentanil requirement. Secondary outcomes included the need for postoperative morphine titration, incidence of nausea and vomiting, respiratory distress and pain scores in the first 24hours. RESULTS Between December 2013 and September 2016, 60 obese patients (i.e. 30 per group) were included. The mean hourly consumption of sufentanil was significantly lower in the ANI+ group (0.15±0.05μgkg-1h-1 versus 0.17±0.05μgkg-1h-1, P=0.038). We found no difference between groups regarding the incidence of nausea and vomiting, acute respiratory distress, the need for postoperative morphine titration, or pain scores in the first 24 postoperative hours. CONCLUSION The use of ANI monitoring might reduce intraoperative consumption of sufentanil during bariatric surgery but does not appear to be accompanied by a reduction in its side effects.