Prevalence and Risk Factors for Thrombotic Complications Following Venovenous Extracorporeal Membrane Oxygenation: A CT Scan Study.

OBJECTIVES: The aims of this study were to: 1) analyze the cannula-associated deep vein thrombosis frequency after venovenous extracorporeal membrane oxygenation using a CT scan and 2) identify the associated risk factors for cannula-associated deep vein thrombosis. DESIGN: Retrospective observational analysis at a single center. SETTING: Tertiary referral university teaching hospital. PATIENTS: Patients under venovenous extracorporeal membrane oxygenation with a femorofemoral or femorojugular cannulation admitted for acute respiratory distress syndrome or primary graft dysfunction after pulmonary transplantation. CT scan was performed within 4 days after decannulation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We included 105 of 228 patients screened. Bacterial pneumonia was the main indication of venovenous extracorporeal membrane oxygenation (46.7%). CT scans were performed at a median of 2 days (1-3 d) after decannulation. Cannula-associated deep vein thrombosis was found in 75 patients (71.4%) despite it having a mean activated partial thromboplastin time ratio of 1.60 ± 0.31. Femorofemoral cannulation induced femoral cannula-associated deep vein thrombosis more frequently than femorojugular cannulation (69.2% vs 63.1%, respectively; p = 0.04). Seventeen of the 105 patients (16.2%) had a pulmonary embolism. Multivariate logistic regression analysis showed that higher the percentage of thrombocytopenia less than 100 G/L during extracorporeal membrane oxygenation period, lower the risk for developing cannula-associated deep vein thrombosis (hazard ratio, 0.98; 95% CI, 0.98-1.00; p = 0.02). CONCLUSIONS: Cannula-associated deep vein thrombosis after venovenous extracorporeal membrane oxygenation is a frequent complication. This plead for a systematic vascular axis imaging after venovenous extracorporeal membrane oxygenation. Thrombocytopenia is associated with a reduction in the occurrence of thrombotic events.

Evaluation of Almitrine Infusion During Veno-Venous Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome in Adults.

This single-center case series investigated the effect of almitrine infusion on PaO2/fraction of inspired oxygen (FIO2) in 25 patients on veno-venous extracorporeal membrane oxygenation for severe acute respiratory distress syndrome. A positive trial was defined as an increase of PaO2/FIO2 ratio ≥20%. Thirty-two trials were performed. Twenty (62.5%, 95% confidence interval, 37.5%-75%) trials in 18 patients were positive, with a median PaO2/FIO2 ratio increase of 35% (25%-43%). A focal acute respiratory distress syndrome and inhaled nitric oxide therapy were more frequent in patients with a positive response to almitrine. We observed no complications of almitrine use.

Venous-to-Arterial Carbon Dioxide Partial Pressure Difference: Predictor of Septic Patient Prognosis Depending on Central Venous Oxygen Saturation.

This study aimed to assess the viability of using the venous-to-arterial carbon dioxide partial pressure difference (P(v-a)CO2) to predict clinical worsening of septic shock, depending on central venous oxygen saturation (ScvO2). The prospective, observational, multicentric study conducted in three intensive care units (ICUs) included all patients with a septic shock episode during the first 6 h, with 122 patients assessed. Clinical worsening was defined as an increase of sequential organ failure assessment (SOFA) scores ≥1 (ΔSOFA ≥1) within 2 days. To assess the ability of P(v-a)CO2 to predict clinical worsening, univariate and multivariate analyses were performed according to ΔSOFA. A receiver-operating characteristic (ROC) analysis was used to confirm model predictions. Associations between P(v-a)CO2 and mortality were explored using correlations. Using multivariate analyses, two independent factors associated with ΔSOFA at least 1 were identified: an averaged 6-h value of lactate concentration (Lac [1-6]) (odds ratios [ORs], 2.43 [95% confidence interval, CI, 1.20-4.89]; P = 0.013) and an averaged 6-h value of P(v-a)CO2 (P(v-a)CO2 [1-6]) (OR, 1.49 [95% CI, 1.04-2.15]; P = 0.029). ROC analysis confirmed that Lac [1-6] and P(v-a)CO2 [1-6] were significantly associated with ΔSOFA at least 1, whereas ScvO2 [1-6] was not. Finally, ΔSOFA at least 1 was associated with higher 28-day (76% vs. 10%, P = 0.001) and ICU (83% vs. 12%, P = 0.001) mortality rates, which were higher in patients with P(v-a)CO2 [1-6] more than 5.8 mmHg (57% vs. 33%; P = 0.012). In conclusion, P(v-a)CO2 may help predict outcomes for septic shock patients regardless of ScvO2 values.

Non-ventilatory therapies for acute respiratory distress syndrome.

Acute respiratory distress syndrome (ARDS) commonly affects intensive care unit patients and is associated with high mortality. In addition to etiologic treatment and protective ventilation, non-ventilatory therapies represent a significant part of ARDS care. Pharmacological treatments, extra corporeal devices and prone positioning are commonly grouped under this term. Studies have evaluated the individual effects of some of these non-ventilatory therapies in large randomized controlled trials. Recent advances concerning the beneficial use of neuromuscular blocking agents and prone positioning deserve attention. Conversely, the use of inhaled nitric oxide and almitrine remains to be specified. The debate concerning the role of corticosteroids could be renewed considering the emergence of new biomarkers. Finally, the use of extracorporeal membrane oxygenation and extra-corporeal CO2 removal remain under question. The aim of this review is to summarize the latest data concerning the mainly used non-ventilatory therapies and to integrate them into a global strategy of ARDS patient care.

How to reduce cisatracurium consumption in ARDS patients: the TOF-ARDS study.

BACKGROUND: Neuromuscular blocking agents (NMBAs) have been shown to improve the outcome of the most severely hypoxemic, acute respiratory distress syndrome (ARDS) patients. However, the recommended dosage as well as the necessity of monitoring the neuromuscular block is unknown. We aimed to evaluate the efficiency of a nurse-directed protocol of NMBA administration based on a train-of-four (TOF) assessment to ensure a profound neuromuscular block and decrease cisatracurium consumption compared to an elevated and constant dose regimen. A prospective open labeled study was conducted in two medical intensive care units of two French university hospitals. Consecutive ARDS patients with a PaO2/FiO2 ratio less than 120 with a PEEP ≥5 cm H2O were included. Cisatracurium administration was driven by the nurses according to an algorithm based on TOF monitoring. The primary endpoint was cisatracurium consumption. The secondary endpoints included the quality of the neuromuscular block, the occurrence of adverse events, and the evolution of ventilatory and blood gas parameters. RESULTS: Thirty patients were included. NMBAs were used for 54 ± 30 h. According to this new algorithm, the initial dosage of cisatracurium was 11.8 ± 2 mg/h, and the final dosage was 14 ± 4 mg/h, which was significantly lower than in the ACURASYS study protocol (37.5 mg/h with a constant infusion rate (p < 0.001). The overall cisatracurium dose used was 700 ± 470 mg in comparison with 2040 ± 1119 mg for patients had received the ACURASYS dosage for the same period (p < 0.001). A profound neuromuscular block (TOF = 0, twitches at the ulnar site) was obtained from the first hour in 70% of patients. Modification of the cisatracurium dosage was not performed from the beginning to the end of the study in 60% of patients. Patient-ventilator asynchronies occurred in 4 patients. CONCLUSION: A nurse-driven protocol based on TOF monitoring for NMBA administration in ARDS patients was able to decrease cisatracurium consumption without significantly affecting the quality of the neuromuscular block.

Venovenous extracorporeal membrane oxygenation devices-related colonisations and infections.

BACKGROUND: Nosocomial infections occurring during extracorporeal membrane oxygenation (ECMO) support have already been reported, but few studied infections directly related to ECMO devices. This study aims to evaluate the rate of both colonisations and infections related to ECMO devices at the time of ECMO removal. RESULTS: We included all consecutive adult patients treated with venovenous ECMO (VV-ECMO) for at least 48 h during a 34-month study. At the time of ECMO removal, blood cultures, swab cultures on insertion cannula site and intravascular cannula extremity cultures were systematically performed. Each ECMO device was classified according to the infectious status into three groups: (1) uninfected/uncolonised ECMO device, (2) ECMO device colonisation and (3) ECMO device infection. Ninety-nine patients underwent 103 VV-ECMO, representing 1472 ECMO days. The ECMO device infection rate was 9.7% (10 events), including 7 ECMO device-related bloodstream infections (6.8%). The ECMO device colonisation rate was 32% (33 events). No difference was observed between the three groups, regarding days of mechanical ventilation, ICU length of stay, ICU mortality and in-hospital mortality. We observed a longer ECMO duration in the ECMO device colonisation group as compared to the uninfected/uncolonised ECMO device group [12 (9-20 days) vs. 5 days (5-16 days), respectively, p < 0.05]. CONCLUSIONS: At the time of ECMO removal, systematic blood culture and intravascular extremity cannula culture may help to diagnose ECMO device-related infection. We reported a quite low infection rate related to ECMO device. Further studies are needed to evaluate the benefits of systematic strategies of cannula culture at the time of ECMO removal.

Effects of neuromuscular blockers on transpulmonary pressures in moderate to severe acute respiratory distress syndrome.

PURPOSE: To investigate whether neuromuscular blocking agents (NMBA) exert beneficial effects in acute respiratory distress syndrome (ARDS) by reason of their action on respiratory mechanics, particularly transpulmonary pressures (P L). METHODS: A prospective randomised controlled study in patients with moderate to severe ARDS within 48 h of the onset of ARDS. All patients were monitored by means of an oesophageal catheter and followed up for 48 h. Moderate ARDS patients were randomised into two groups according to whether they were given a 48-h continuous infusion of cisatracurium besylate or not (control group). Severe ARDS patients did not undergo randomisation and all received cisatracurium besylate per protocol. The changes during the 48-h study period in oxygenation and in respiratory mechanics, including inspiratory and expiratory P L and driving pressure, were assessed and compared. Delta P L (∆P L) was defined as inspiratory P L minus expiratory P L. RESULTS: Thirty patients were included, 24 with moderate ARDS and 6 with severe ARDS. NMBA infusion was associated with an improvement in oxygenation in both moderate and severe ARDS, accompanied by a decrease in both plateau pressure and total positive end-expiratory pressure. The mean inspiratory and expiratory P L were higher in the moderate ARDS group receiving NMBA than in the control group. In contrast, there was no change in either driving pressure or ∆P L related to NMBA administration. CONCLUSIONS: NMBA could exert beneficial effects in patients with moderate ARDS, at least in part, by limiting expiratory efforts.