Management of liver failure in general intensive care unit.

OBJECTIVE: To produce French guidelines on Management of Liver failure in general Intensive Care Unit (ICU). DESIGN: A consensus committee of 23 experts from the French Society of Anesthesiology and Critical Care Medicine (Société française d'anesthésie et de réanimation, SFAR) and the French Association for the Study of the Liver (Association française pour l'étude du foie, AFEF) was convened. A formal conflict-of-interest (COI) policy was developed at the start of the process and enforced throughout. The entire guideline process was conducted independently of any industrial funding. The authors were advised to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide their assessment of the quality of evidence. The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasised. Some recommendations were ungraded. METHODS: Two fields were defined: acute liver failure (ALF) and cirrhotic patients in general ICU. The panel focused on three questions with respect to ALF: (1) Which etiological examinations should be performed to reduce morbidity and mortality? (2) Which specific treatments should be initiated rapidly to reduce morbidity and mortality? (3) Which symptomatic treatment should be initiated rapidly to reduce morbidity and mortality? Seven questions concerning cirrhotic patients were addressed: (1) Which criteria should be used to guide ICU admission of cirrhotic patients in order to improve their prognosis? (2) Which specific management of kidney injury should be implemented to reduce morbidity and mortality in cirrhotic ICU patients? (3) Which specific measures to manage sepsis in order to reduce morbidity and mortality in cirrhotic ICU patients? (4) In which circumstances, human serum albumin should be administered to reduce morbidity and mortality in cirrhotic ICU patients? (5) How should digestive haemorrhage be treated in order to reduce morbidity and mortality in cirrhotic ICU patients? (6) How should haemostasis be managed in order to reduce morbidity and mortality in cirrhotic ICU patients? And (7) When should advice be obtained from an expert centre in order to reduce morbidity and mortality in cirrhotic ICU patients? Population, intervention, comparison and outcome (PICO) issues were reviewed and updated as required, and evidence profiles were generated. An analysis of the literature and recommendations was then performed in accordance with the GRADE® methodology. RESULTS: The SFAR/AFEF Guidelines panel produced 18 statements on liver failure in general ICU. After two rounds of debate and various amendments, a strong agreement was reached on 100% of the recommendations: six had a high level of evidence (Grade 1 ±), seven had a low level of evidence (Grade 2 ±) and six were expert judgments. Finally, no recommendation was provided with respect to one question. CONCLUSIONS: Substantial agreement exists among experts regarding numerous strong recommendations on the optimum care of patients with liver failure in general ICU.

[Preoperative risk and perioperative management of obese patients]. / Risque pré-opératoire et gestion péri-opératoire des patients obèses.

The obese patient is at an increased risk of perioperative complications. Most importantly, these include difficult access to the airways (intubation, difficult or impossible ventilation), and post-extubation respiratory distress secondary to the development of atelectasis or obstruction of the airways, sometimes associated with the use of morphine derivatives. The association of obstructive sleep apnea syndrome (OSA) with obesity is very common, and induces a high risk of peri- and postoperative complications. Preoperative OSA screening is crucial in the obese patient, as well as its specific management: use of continuous positive pre, per and postoperative pressure. For any obese patient, the implementation of protocols for mask ventilation and/or difficult intubation and the use of protective ventilation, morphine-sparing strategies and a semi-seated positioning throughout the care, is recommended, combined with close monitoring postoperatively. The dosage of anesthetic drugs should be based on the theoretical ideal weight and then titrated, rather than dosed to the total weight. Monitoring of neuromuscular blocking should be used where appropriate, as well as monitoring of the depth of anesthesia. The occurrence of intraoperative recall is indeed more frequent in the obese patient than in the non-obese patient. Appropriate prophylaxis against venous thromboembolic disease and early mobilization are recommended, as thromboembolic disease is increased in the obese patient. The use of non-invasive ventilation to prevent the occurrence of acute post-operative respiratory failure and for its treatment is particularly effective in obese patients. In case of admission to ICU, an individualized ventilatory management based on pathophysiology and careful monitoring should be initiated.

Analgesia nociception index for the assessment of pain in critically ill patients: a diagnostic accuracy study.

BACKGROUND: Behavioural pain tools are used in Intensive Care Unit (ICU) patients unable to self-report their pain-intensity but need sustained efforts to educate and train the ICU team because of the subjective nature of these clinical tools. This study measured the validity and performance of an electrophysiological monitoring tool based on the spectral analysis of heart rate variability, the Analgesia Nociception Index (ANI) which varies from 0 (minimal parasympathetic tone, maximal stress-response and pain) to 100 (maximal parasympathetic tone, minimal stress-response and pain). METHODS: Mean-ANI (ANIm) and Instant-ANI (ANIi) were continuously recorded then compared with the Behavioral Pain Scale (BPS) before, during and after routine care procedures in critically-ill non-comatose patients. RESULTS: 969 assessments were performed in 110 patients. ANIi was the most discriminative pain tool. It was significantly correlated with BPS (r=-0.30; 95%CI -0.37 to -0.25; P<0.001). For an ANIi threshold of 42.5, the sensitivity, specificity, positive and negative predictive values were respectively 61.4%, 77.4%, 37.0%, and 90.4%. Compared with the BPS, ANIi had no significantly different ability to change during turning and tracheal-suctioning but changed significantly more during dressing change. ANIi increased independently with age, obesity and severity of illness, and controlled mechanical-ventilation, vasopressors use and analgesia. ANIi decreased independently when vigilance status and respiratory rate increased. ANIm demonstrated poor psychometric properties to detect pain. CONCLUSIONS: Despite low sensitivity/specificity, ANIi≥43 had a Negative-Predictive-Value of 90%. Hence ANIi may be of highest benefit for excluding significant pain. A randomized controlled trial should compare sedation-analgesia protocols based on ANIi to presently recommended behavioural-pain-tools.

Difficult intubation in obese patients: incidence, risk factors, and complications in the operating theatre and in intensive care units.

BACKGROUND: Intubation procedure in obese patients is a challenging issue both in the intensive care unit (ICU) and in the operating theatre (OT). The objectives of the study were (i) to compare the incidence of difficult intubation and (ii) its related complications in obese patients admitted to ICU and OT. METHODS: We conducted a multicentre prospective observational cohort study in ICU and OT in obese (BMI≥30 kg m(-2)) patients. The primary endpoint was the incidence of difficult intubation. Secondary endpoints were the risk factors for difficult intubation, the use of difficult airway management techniques, and severe life-threatening complications related to intubation (death, cardiac arrest, severe hypoxaemia, severe cardiovascular collapse). RESULTS: In cohorts of 1400 and 11 035 consecutive patients intubated in ICU and in the OT, 282 (20%) and 2103 (19%) were obese. In obese patients, the incidence of difficult intubation was twice more frequent in ICU than in the OT (16.3% vs 8.2%, P<0.01). In both cohorts, risk factors for difficult intubation were Mallampati score III/IV, obstructive sleep apnoea syndrome, and reduced mobility of cervical spine, while limited mouth opening, severe hypoxaemia, and coma appeared only in ICU. Specific difficult airway management techniques were used in 66 (36%) cases of difficult intubation in obese patients in the OT and in 10 (22%) cases in ICU (P=0.04). Severe life-threatening complications were significantly more frequent in ICU than in the OT (41.1% vs 1.9%, relative risk 21.6, 95% confidence interval 15.4-30.3, P<0.01). CONCLUSIONS: In obese patients, the incidence of difficult intubation was twice more frequent in ICU than in the OT and severe life-threatening complications related to intubation occurred 20-fold more often in ICU. CLINICAL TRIAL REGISTRATION: Current controlled trials. Identifier: NCT01532063.

How to preoxygenate in operative room: healthy subjects and situations "at risk".

Intubation is one of the most common procedures performed in operative rooms. It can be associated with life-threatening complications when difficult airway access occurs, in patients who cannot tolerate even a slight hypoxemia or when performed in patients at risk of oxygen desaturation during intubation, as obese, critically-ill and pregnant patients. To improve intubation safety, preoxygenation is a major technique, extending the duration of safe apnoea, defined as the time until a patient reaches an arterial saturation level of 88% to 90%, to allow for placement of a definitive airway. Preoxygenation consists in increasing the lung stores of oxygen, located in the functional residual capacity, and helps preventing hypoxia that may occur during intubation attempts. Obese, critically-ill and pregnant patients are especially at risk of reduced effectiveness of preoxygenation because of pathophysiological modifications (reduced functional residual capacity (FRC), increased risk of atelectasis, shunt). Three minutes tidal volume breathing or 3-8 vital capacities are recommended in general population, mostly allowing achieving a 90% end-tidal oxygen level. Recent studies have indicated that in order to maximize the value of preoxygenation (i.e, oxygenation stores) obese and critically-ill patients can benefit from the combination of breathing 100% oxygen and non-invasive positive pressure ventilation (NIV) with end-expiratory positive pressure (PEEP) in the proclive position (Trendelenburg reverse). Recruitment manoeuvres may be of interest immediately after intubation to limit the risk of lung derecruitment. Further studies are needed in the field of preoxygenation in pregnant women.

Non-invasive ventilation after surgery.

After surgery, hypoxemia and/or acute respiratory failure (ARF) mainly develop following abdominal and/or thoracic surgery. Anesthesia, postoperative pain and surgery will induce respiratory modifications: hypoxemia, pulmonary volumes decrease and atelectasis associated to a restrictif syndrome and a diaphragm dysfunction. Maintenance of adequate oxygenation in the postoperative period is of major importance, especially when pulmonary complications such as ARF occur. Although invasive endotracheal mechanical ventilation has remained the cornerstone of ventilatory strategy for many years for severe acute respiratory failure, several studies have shown that mortality associated with pulmonary disease is largely related to complications of postoperative reintubation and mechanical ventilation. Therefore, major objectives for anesthesiologists and surgeons are first to prevent the occurrence of postoperative complications and second if ARF occurs is to ensure oxygen administration and carbon dioxide CO2 removal while avoiding intubation. Non-invasive ventilation (NIV) does not require endotracheal tube or tracheotomy and its use is well established to prevent ARF occurrence (prophylactic treatment) or to treat ARF to avoid reintubation (curative treatment). Studies shows that patient-related risk factors, such as chronic obstructive pulmonary disease (COPD), age older than 60 years, American Society of Anesthesiologists ASA class of II or higher, obesity, functional dependence, and congestive heart failure, increase the risk for postoperative pulmonary complications. Rationale for postoperative NIV use is the same as the post-extubation NIV use plus the specificities due to the respiratory modifications induced by the surgery and anesthesia. Postoperative NIV improves gas exchange, decreases work of breathing and reduces atelectasis. The aims of this article are (1) to review the main respiratory modifications induced by surgery and anesthesia which justify postoperative NIV use (2) to offer some recommendations to apply safely postoperative NIV and (3) to present the main results obtained with preventive and curative NIV in a surgical context.

[Esophageal cancer surgery: evolution of pain management, hemodynamics and ventilation practices during 16 years]. / Œsophagectomie carcinologique : 16ans d'évolution des pratiques anesthésiques ventilatoires, hémodynamiques et analgésiques.

OBJECTIVE: To describe the evolution of perioperative anesthesia practices in for esophageal cancer surgery. PATIENTS AND METHODS: We conducted an observational retrospective study in a single center evaluating main perioperative practices during 16 years (1994-2009). Statistical analysis was done on 4 chronologic quartiles of same sample size. RESULTS: Two hundred and seven consecutive patients were included during the 4 periods 1994-1997 (n=52), 1997-1999 (n=52), 1999-2003 (n=52) and 2004-2009 (n=51). The main significant evolutions between the first and the fourth period were observed: (i) in ventilation: lower tidal volume (9.6[8.6-10.6] vs 7.6[7.0-8.3] mL/kg of ideal body weight (IBW), p<0.01), increased use of Positive End Expiratory Pressure (0 vs 83%, p<0.001) and increased use of post-operative non-invasive ventilation (0 vs 51%, p<0.001); (ii) in hemodynamic management: lower fluid replacement (20.6 [16.0-24.6] vs 12.6 [9.7-16.2] mL/h/kg of IBW, p<0.001); (iii) in analgesia: increased use of epidural thoracic anesthesia (31 vs 57%, p<0.001). Peroperative bleeding, type of fluid replacement, length of mechanical ventilation, length of stay in intensive care unit, ventilatory free days and mortality at day 28 didn't change. CONCLUSIONS: During these previous years, anesthesia practices in ventilation, hemodynamics and analgesia for esophageal cancer surgery have changed.

[Risk of barotrauma when using non-reinhalation Waters valves: a comparative study on bench test]. / Risque barotraumatique avec des valves de non-réinhalation de Waters: étude comparative sur banc d'essai.

OBJECTIVE: Manual ventilation is delivered in the operating room or the intensive care unit to intubated or non-intubated patients, using non-rebreathing systems such as the Waters valve. New generation Waters valves are progressively replacing the historic Waters valve. The aim of this study was to evaluate maximal pressure delivered by these 2 valves. TYPE OF STUDY: Bench test. MATERIAL AND METHOD: Thirty-two different conditions were tested, according to 2 oxygen flow rates (10 and 20L/min), without (static condition) or with manual insufflations (dynamic condition) and 4 valve expiratory opening pressures. The primary endpoint was maximal pressure measured at the exit of the valve, connected to a model lung and a bench test. RESULTS: Measured pressures were different for most evaluated conditions. Increasing oxygen flow from 10 to 20L/min increased maximal pressure for both valves. Increasing valve expiratory opening pressure induced a significant increase in maximal pressure for the new generation valve (from 4 to 61cmH2O in static conditions and from 18 to 68cmH2O in dynamic conditions). For the historic valve, maximal pressure increased significantly but remained below 15cmH2O in both static and dynamic conditions. CONCLUSION: Use of new generation Waters valves should be different from historic Waters valves. Indeed, barotrauma could be caused by badly adapted valve expiratory opening pressure settings.

Comparison of three high flow oxygen therapy delivery devices: a clinical physiological cross-over study.

AIM: High-flow-oxygen-therapy is provided by various techniques and patient interfaces, resulting in various inspired-fraction of oxygen (FiO2) and airway-pressure levels. However, tracheal measurements have never been performed. METHODS: Three oxygen-delivery-devices were evaluated: 1) standard-high-flow-oxygen-facemask with reservoir-bag, 2) Optiflow(TM)-high-flow-nasal-cannulae and 3) Boussignac(TM)-oxygen-therapy-system. Main judgment criteria were airway-pressure and FiO2 measured in the trachea. The three devices were randomly evaluated in cross-over in 10 Intensive-Care-Unit patients using three oxygen flow-rates (15, 30 and 45 L/min) and two airway-tightness conditions (open and closed mouth). Airway-pressures and FiO2 were measured by a tracheal-catheter inserted through the hole of a tracheotomy tube. Comfort was evaluated by self-reporting. Data are presented as median [25-75th]. RESULTS: 1) Regarding oxygen-delivery devices, BoussignacTM provided the highest mean tracheal pressure (13.9 [10.4-14.5] cmH20) compared to Optiflow(TM) (2 [1-2.3] cmH2O, P<0.001). BoussignacTM provided both positive inspiratory and expiratory airway-pressures, whereas Optiflow(TM) provided only positive expiratory airway-pressure. Reservoir-bag-facemask provided airway pressure close to zero. For FiO2, highest value was obtained for both Optiflow(TM) and facemask (90%) compared to Boussignac(TM) (80%), P<0.01. 2) Regarding oxygen-flow, airway-pressure and FiO2 systematically increased with oxygen-flow with the three devices except airway-pressure for the facemask. 3) Regarding the open-mouth position, mean airway-pressure decreased with Optiflow(TM) only (2 [1.2-3.3] vs. 0.6 [0.3-1] cmH2O, P<0.001). Opening the mouth had little impact on FiO2. 4) finally, discomfort-intensities were low for both Optiflow(TM) and reservoir-bag-facemask compared to Boussignac(TM), P<0.01. CONCLUSION: On one hand, Boussignac(TM) is the only device that generates a relevant positive-airway-pressure during both inspiration-and-expiration, independently of mouth-position. Optiflow(TM) provides a low positive-airway-pressure (<4 cmH2O), highly dependent of mouth-closing. The reservoir-bag-facemask provides no positive-airway-pressure. On the other hand, FiO2 are slightly but significantly higher for Optiflow(TM) and reservoir-bag-facemask than for Boussignac(TM). Discomfort was lesser for Optiflow(TM) and reservoir-bag-facemask.

A multicentre observational study of intra-operative ventilatory management during general anaesthesia: tidal volumes and relation to body weight.

We conducted an observational prospective multicenter study to describe the practices of mechanical ventilation, to determine the incidence of use of large intra-operative tidal volumes (≥10 ml.kg(-1) of ideal body weight) and to identify patient factors associated with this practice. Of the 2960 patients studied in 97 anaesthesia units from 49 hospitals, volume controlled mode was the most commonly used (85%). The mean (SD) tidal volume was 533 (82) ml; 7.7 (1.3) ml.kg(-1) (actual weight) and 8.8 (1.4) ml.kg(-1) (ideal body weight)). The lungs of 381 (18%) patients were ventilated with a tidal volume>10 ml.kg(-1) ideal body weight. Being female (OR 5.58 (95% CI 4.20-7.43)) and by logistic regression, underweight (OR 0.06 (95% CI 0.01-0.45)), overweight (OR 1.98 (95% CI 1.49-2.65)), obese (OR 5.02 (95% CI 3.51-7.16)), severely obese (OR 10.12 (95% CI 5.79-17.68)) and morbidly obese (OR 14.49 (95% CI 6.99-30.03)) were the significant (p ≤ 0.005) independent factors for the use of large tidal volumes during anaesthesia.

Influence of opioid choice on mechanical ventilation duration and ICU length of stay.

BACKGROUND: The aim of this study was to assess the impact on mechanical ventilation and ICU outcomes of substituting remifentanil for sufentanil, in an analgesia-based sedation protocol. A database of data prospectively collected was retrospectively analyzed. The study was carried out in a 16-bed tertiary-care ICU. METHODS: The study included 1544 mechanically ventilated patients admitted from January 2001 to December 2006. Patients were compared between two consecutive phases. Analgesia-based sedation guidelines were the same, except for the opiate used. The patient-to-nurse ratio (2.5) and ventilator weaning practices remained unchanged. 794 patients were included during the sufentanil phase, and 750 during the remifentanil phase. Remifentanil was associated with significantly less time spent on mechanical ventilation (10 days[3-21] vs. 14 days[3-27], P<0.01) and in the ICU (16 days[3-22] vs. 19 days[4-26], P<0.01). The difference was significant for patients ventilated no longer than four days (P=0.0035) but not for patients ventilated more than four days (P=0.058). Sedation target on the Ramsay scale was reached more often with remifentanil. The use and amount of hypnotic agents in addition to the opiate were significantly lower with remifentanil. The cost of analgesia-based sedation was similar in the sufentanil and the remifentanil group. CONCLUSION: Our study suggests that using a short-acting opiate with short context-sensitive half-life in an analgesia-based sedation protocol may significantly decrease the duration of mechanical ventilation and the ICU length of stay even though not significantly in long term sedation, while improving the achievement of sedation goals despite a lower requirement for adjunctive hypnotic agents, with no additional costs.

[Causes of early mortality after liver transplantation: a twenty-years single centre experience]. / Mortalité trois mois après transplantation hépatique : étude monocentrique sur une période de vingt ans.

OBJECTIVE: To define the causes of mortality of patients who died within the first three months after a liver transplantation. TYPE OF STUDY: Retrospective, observational, and single centre study. PATIENTS AND METHODS: Between March 1989 and July 2010, all patients who died within three months after a liver transplantation were included. Demographic characteristics, preoperative and peroperative data, donor characteristics, postoperative complications and causes of mortality were collected. RESULTS: Among the 788 performed liver transplantations, 76 patients died in intensive care unit (11%). The main indications of liver transplantation were alcoholic cirrhosis (30%), hepatitis C (28%), hepatocarcinoma (15%), primitive or secondary biliary cirrhosis (10%). Fifty percent of the patients were categorized as Child C. The main causes of death were non-function or dysfunction with retransplantation contra-indication graft (18%), sepsis (18%), neurological complications (12%), hemorrhagic shock (13%), (9%), multiorgan failures (5%), cardiac complications (6%). CONCLUSION: In this study, the main causes of mortality were infectious, neurological and hemorrhagic. These results emphasize the necessity for better control of sepsis, haemorrhage and immunosupressors.

[Gas embolism: another story related to a central venous catheter withdraw]. / Nouvelle observation d'une embolie gazeuse au retrait d'un cathéter veineux central.

Paradoxical gas embolism is rare but life threatening complication of central venous access. In this observation, we report a paradoxical gas embolism accompanied by an acute respiratory failure and a coma following a jugular central venous access withdrawal in a liver transplanted patient. Following this observation, we discuss the prevention of gas embolism accidents and the hyperbaric oxygen therapy for its management.

[Severe and acute pancreatitis admitted in intensive care: a prospective epidemiological multiple centre study using CClin network database]. / Épidémiologie, pronostic et complications infectieuses nosocomiales des pancréatites aiguës graves en réanimation: étude prospective multicentrique à partir de la base de données CClin Sud-Est.

OBJECTIVES: To describe the demographic characteristics, incidence of extra-abdominal hospital-acquired infections and outcome of patients admitted to intensive care unit (ICU) with severe acute pancreatitis. STUDY DESIGN: A retrospective, observational multiple center (65 centers) analysis of prospectively acquired data. PATIENTS AND METHODS: During 2 years, all consecutive admitted patients to ICU for severe acute pancreatitis in the centers participating in the nosocomial infections surveillance network CClin Sud-Est were included. Patients whose ICU stay was less than 48 hours were not included. Demographic characteristics, extra-abdominal hospital-acquired infections and clinical course were described. RESULTS: During the study period, 510 patients were included which represented 2 % of patients with a length of stay longer than 48 hours in the 65 participating ICUs. The global attack rate of extra-abdominal hospital-acquired infections (pneumonia, bacteremia, urinary tract or central venous catheter infection) was 23 % in overall patients and it was 33 % in the 294 mechanically ventilated patients. ICU mortality was 20 % in overall patients and it was 34 % in mechanically ventilated patients. CONCLUSION: Severe acute pancreatitis represents 2 % of ICU stay longer than 48 hours. Its clinical course is frequently complicated by hospital-acquired infections and is associated with an high ICU mortality rate. This epidemiological observational study may be used for calculating sample size for future multicenter interventional therapeutic studies.