Biblio du Mois: Avril 2015
27 avril 2015
Dans La Biblio du Mois, sommeil, mémorisation et chirurgie cardiaque, deux revues de la litérature du NEJM sur la balance hydrique et la fibrose pulmonaire. Et après avoir été évalué aux USA (ProCESS) et en Australie (ARISE): l’EGDT en Angleterre…
Bonne lecture !
Trial of Early, Goal-Directed Resuscitation for Septic Shock in England
BACKGROUND. Early, goal-directed therapy (EGDT) is recommended in international guidelines for the resuscitation of patients presenting with early septic shock. However, adoption has been limited, and uncertainty about its effectiveness remains.
METHODS. We conducted a pragmatic randomized trial with an integrated cost-effectiveness analysis in 56 hospitals in England. Patients were randomly assigned to receive either EGDT (a 6-hour resuscitation protocol) or usual care. The primary clinical outcome was all-cause mortality at 90 days.
RESULTS. We enrolled 1260 patients, with 630 assigned to EGDT and 630 to usual care. By 90 days, 184 of 623 patients (29.5%) in the EGDT group and 181 of 620 patients (29.2%) in the usual-care group had died (relative risk in the EGDT group, 1.01; 95% confidence interval [CI], 0.85 to 1.20; P=0.90), for an absolute risk reduction in the EGDT group of −0.3 percentage points (95% CI, −5.4 to 4.7). Increased treatment intensity in the EGDT group was indicated by increased use of intravenous fluids, vasoactive drugs, and red-cell transfusions and reflected by significantly worse organ-failure scores, more days receiving advanced cardiovascular support, and longer stays in the intensive care unit. There were no significant differences in any other secondary outcomes, including health-related quality of life, or in rates of serious adverse events. On average, EGDT increased costs, and the probability that it was cost-effective was below 20%.
CONCLUSIONS. In patients with septic shock who were identified early and received intravenous antibiotics and adequate fluid resuscitation, hemodynamic management according to a strict EGDT protocol did not lead to an improvement in outcome.
Liberal or Restrictive Transfusion after Cardiac Surgery
BACKGROUND. Whether a restrictive threshold for hemoglobin level in red-cell transfusions, as compared with a liberal threshold, reduces postoperative morbidity and health care costs after cardiac surgery is uncertain.
METHODS. We conducted a multicenter, parallel-group trial in which patients older than 16 years of age who were undergoing nonemergency cardiac surgery were recruited from 17 centers in the United Kingdom. Patients with a postoperative hemoglobin level of less than 9 g per deciliter were randomly assigned to a restrictive transfusion threshold (hemoglobin level <7.5 g per deciliter) or a liberal transfusion threshold (hemoglobin level <9 g per deciliter). The primary outcome was a serious infection (sepsis or wound infection) or an ischemic event (permanent stroke [confirmation on brain imaging and deficit in motor, sensory, or coordination functions], myocardial infarction, infarction of the gut, or acute kidney injury) within 3 months after randomization. Health care costs, excluding the index surgery, were estimated from the day of surgery to 3 months after surgery.
RESULTS. A total of 2007 patients underwent randomization; 4 participants withdrew, leaving 1000 in the restrictive-threshold group and 1003 in the liberal-threshold group. Transfusion rates after randomization were 53.4% and 92.2% in the two groups, respectively. The primary outcome occurred in 35.1% of the patients in the restrictive-threshold group and 33.0% of the patients in the liberal-threshold group (odds ratio, 1.11; 95% confidence interval [CI], 0.91 to 1.34; P=0.30); there was no indication of heterogeneity according to subgroup. There were more deaths in the restrictive-threshold group than in the liberal-threshold group (4.2% vs. 2.6%; hazard ratio, 1.64; 95% CI, 1.00 to 2.67; P=0.045). Serious postoperative complications, excluding primary-outcome events, occurred in 35.7% of participants in the restrictive-threshold group and 34.2% of participants in the liberal-threshold group. Total costs did not differ significantly between the groups.
CONCLUSIONS. A restrictive transfusion threshold after cardiac surgery was not superior to a liberal threshold with respect to morbidity or health care costs.
Surgical Ablation of Atrial Fibrillation during Mitral-Valve Surgery
BACKGROUND. Among patients undergoing mitral-valve surgery, 30 to 50% present with atrial fibrillation, which is associated with reduced survival and increased risk of stroke. Surgical ablation of atrial fibrillation has been widely adopted, but evidence regarding its safety and effectiveness is limited.
METHODS. We randomly assigned 260 patients with persistent or long-standing persistent atrial fibrillation who required mitral-valve surgery to undergo either surgical ablation (ablation group) or no ablation (control group) during the mitral-valve operation. Patients in the ablation group underwent further randomization to pulmonary-vein isolation or a biatrial maze procedure. All patients underwent closure of the left atrial appendage. The primary end point was freedom from atrial fibrillation at both 6 months and 12 months (as assessed by means of 3-day Holter monitoring).
RESULTS. More patients in the ablation group than in the control group were free from atrial fibrillation at both 6 and 12 months (63.2% vs. 29.4%, P<0.001). There was no significant difference in the rate of freedom from atrial fibrillation between patients who underwent pulmonary-vein isolation and those who underwent the biatrial maze procedure (61.0% and 66.0%, respectively; P=0.60). One-year mortality was 6.8% in the ablation group and 8.7% in the control group (hazard ratio with ablation, 0.76; 95% confidence interval, 0.32 to 1.84; P=0.55). Ablation was associated with more implantations of a permanent pacemaker than was no ablation (21.5 vs. 8.1 per 100 patient-years, P=0.01). There were no significant between-group differences in major cardiac or cerebrovascular adverse events, overall serious adverse events, or hospital readmissions.
CONCLUSIONS. The addition of atrial fibrillation ablation to mitral-valve surgery significantly increased the rate of freedom from atrial fibrillation at 1 year among patients with persistent or long-standing persistent atrial fibrillation, but the risk of implantation of a permanent pacemaker was also increased.
Et deux revues:
Molecular Physiology of Water Balance
Fibrosis — A Common Pathway to Organ Injury and Failure
Anesthésie intraveineuse totale versus Desflurane : un meilleur rétablissement pour les patients
Background Two common general anaesthetic methods are total i.v. anaesthesia (TIVA) and inhalation anaesthesia, but it is unclear whether this affects the patient’s perception of their quality of recovery. The Quality of Recovery-40 questionnaire (QoR-40) is a valid and reliable method to evaluate the extent of functional recovery after surgery with general anaesthesia. This study therefore compared patient recovery using the QoR-40 in surgical patients who received TIVA with those who received desflurane anaesthesia.Methods Eighty females (20–65 years old) undergoing thyroid surgery were prospectively recruited and randomized to either the TIVA (effect-site target controlled infusion using propofol and remifentanil) or DES (desflurane inhalation with manual infusion of remifentanil) groups. The QoR-40 was administered by an investigator blind to group allocation before surgery, and postoperative days 1 and 2 (POD1 and POD2). Additional data including the incidence of nausea or vomiting, the consumption of antiemetic and analgesic agents in the post-anaesthesia care unit, and the duration of the hospital stay, were collected in all cases.Results The QoR-40 score on POD1 was significantly higher in the TIVA group compared with the DES group (174 vs 161, respectively; P=0.004), indicating a better quality of recovery in the TIVA group. Among the five dimensions of the QoR-40, physical comfort and physical independence were significantly better on POD1 and POD2 in the TIVA group.Conclusion This study demonstrates that the quality of recovery for female thyroid surgery patients is significantly better with TIVA compared with desflurane anaesthesia.
BIS & MAC pour prévenir la mémorisation per-op
BACKGROUND: Intraoperative awareness with explicit recall is a potentially devastating complication of surgery that has been attributed to low anaesthetic concentrations in the vast majority of cases. Past studies have proposed the determination of an adequate dose for general anaesthetics that could be used to alert providers of potentially insufficient anaesthesia. However, there have been no systematic analyses of appropriate thresholds to develop population-based alerting algorithms for preventing intraoperative awareness.
OBJECTIVE: To identify a threshold for intraoperative alerting that could be applied for the prevention of awareness with explicit recall.
DESIGN: Secondary analysis of a randomised controlled trial (Michigan Awareness Control Study).
SETTING: Three hospitals at a tertiary care centre in the USA.
PATIENTS: Unselected patients presenting for surgery under general anaesthesia.
INTERVENTIONS: Alerts based on end-tidal anaesthetic concentration or bispectral index values.
MAIN OUTCOME MEASURES: Using case and outcomes data from the primary study, end-tidal anaesthetic concentration and bispectral index values were analysed using Youden’s index and c-statistics derived from a receiver operating characteristic curve to determine a specific alerting threshold for the prevention of awareness.
RESULTS: No single population-based threshold that maximises sensitivity and specificity could be identified for the prevention of intraoperative awareness, using either anaesthetic concentration or bispectral index values. The c-statistic for anaesthetic concentration was 0.431 ± 0.046, and 0.491 ± 0.056 for bispectral index values.
CONCLUSION: We could not derive a single population-based alerting threshold for the prevention of intraoperative awareness using either anaesthetic concentration or bispectral index values. These data indicate a need to move towards individualised alerting strategies in the prevention of intraoperative awareness.
BACKGROUND: It is claimed that bispectral index (BIS) and state entropy reflect an identical clinical spectrum, the hypnotic component of anaesthesia. So far, it is not known to what extent different devices display similar index values while processing identical electroencephalogram (EEG) signals.
OBJECTIVE: To compare BIS and state entropy during analysis of identical EEG data. Inspection of raw EEG input to detect potential causes of erroneous index calculation.
DESIGN: Offline re-analysis of EEG data from a randomised, single-centre controlled trial using the Entropy Module and an Aspect A-2000 monitor.
SETTING: Klinikum rechts der Isar, Technische Universität München, Munich.
PATIENTS: Forty adult patients undergoing elective surgery under general anaesthesia.
INTERVENTIONS: Blocked randomisation of 20 patients per anaesthetic group (sevoflurane/remifentanil or propofol/remifentanil). Isolated forearm technique for differentiation between consciousness and unconsciousness.
MAIN OUTCOME MEASURES: Prediction probability (PK) of state entropy to discriminate consciousness from unconsciousness. Correlation and agreement between state entropy and BIS from deep to light hypnosis. Analysis of raw EEG compared with index values that are in conflict with clinical examination, with frequency measures (frequency bands/Spectral Edge Frequency 95) and visual inspection for physiological EEG patterns (e.g. beta or delta arousal), pathophysiological features such as high-frequency signals (electromyogram/high-frequency EEG or eye fluttering/saccades), different types of electro-oculogram or epileptiform EEG and technical artefacts.
RESULTS: PK of state entropy was 0.80 and of BIS 0.84; correlation coefficient of state entropy with BIS 0.78. Nine percent BIS and 14% state entropy values disagreed with clinical examination. Highest incidence of disagreement occurred after state transitions, in particular for state entropy after loss of consciousness during sevoflurane anaesthesia. EEG sequences which led to false ‘conscious’ index values often showed high-frequency signals and eye blinks. High-frequency EEG/electromyogram signals were pooled because a separation into EEG and fast electro-oculogram, for example eye fluttering or saccades, on the basis of a single EEG channel may not be very reliable. These signals led to higher Spectral Edge Frequency 95 and ratio of relative beta and gamma band power than EEG signals, indicating adequate unconscious classification. The frequency of other artefacts that were assignable, for example technical artefacts, movement artefacts, was negligible and they were excluded from analysis.
CONCLUSION: High-frequency signals and eye blinks may account for index values that falsely indicate consciousness. Compared with BIS, state entropy showed more false classifications of the clinical state at transition between consciousness and unconsciousness.
Objective: Characterizing burn sizes that are associated with an increased risk of mortality and morbidity is critical because it would allow identifying patients who might derive the greatest benefit from individualized, experimental, or innovative therapies. Although scores have been established to predict mortality, few data addressing other outcomes exist. The objective of this study was to determine burn sizes that are associated with increased mortality and morbidity after burn.
Design and Patients: Burn patients were prospectively enrolled as part of the multicenter prospective cohort study, Inflammation and the Host Response to Injury Glue Grant, with the following inclusion criteria: 0–99 years old, admission within 96 hours after injury, and more than 20% total body surface area burns requiring at least one surgical intervention.
Setting: Six major burn centers in North America.
Measurements and Main Results: Burn size cutoff values were determined for mortality, burn wound infection (at least two infections), sepsis (as defined by American Burn Association sepsis criteria), pneumonia, acute respiratory distress syndrome, and multiple organ failure (Denver 2 score > 3) for both children (< 16 yr) and adults (16–65 yr). Five hundred seventy-three patients were enrolled, of which 226 patients were children. Twenty-three patients were older than 65 years and were excluded from the cutoff analysis. In children, the cutoff burn size for mortality, sepsis, infection, and multiple organ failure was approximately 60% total body surface area burned. In adults, the cutoff for these outcomes was lower, at approximately 40% total body surface area burned.
Conclusions: In the modern burn care setting, adults with over 40% total body surface area burned and children with over 60% total body surface area burned are at high risk for morbidity and mortality, even in highly specialized centers.
Objectives: To characterize survival outcomes for adult patients with acute myocarditis supported with extracorporeal membrane oxygenation and identify risk factors for in-hospital mortality.
Design: Retrospective review of Extracorporeal Life Support Organization registry database.
Setting: Data reported to Extracorporeal Life Support Organization by 230 extracorporeal membrane oxygenation centers.
Patients: Patients 16 years old or older supported with extracorporeal membrane oxygenation for myocarditis during 1995 to 2011.
Interventions: None.
Measurements and Main Results: There were 150 separate runs of extracorporeal membrane oxygenation for 147 patients with a diagnosis of acute myocarditis in the Extracorporeal Life Support Organization database from 1995 through 2011. Survival to hospital discharge was 61%. Nine patients underwent heart transplantation, and transplant-free survival to discharge was 56%. Extracorporeal membrane oxygenation was deployed during extracorporeal cardiopulmonary resuscitation in 31 patients (21% of the cohort). In a multivariate model evaluating pre–extracorporeal membrane oxygenation and extracorporeal membrane oxygenation support factors, pre–extracorporeal membrane oxygenation arrest (adjusted odds ratio, 2.4; 95% CI, 1.1–5.0) and need for higher extracorporeal membrane oxygenation flows at 4 hours post–extracorporeal membrane oxygenation cannulation (odds ratio, 2.8; 95% CI, 1.1–7.3) were associated with increased odds of in-hospital mortality. In a second multivariate model evaluating adverse events while on extracorporeal membrane oxygenation, central nervous system injury (odds ratio, 26.5; 95% CI, 7.3–96.6), renal failure (odds ratio, 3.6; 95% CI, 1.4–9.3), arrhythmia (odds ratio, 5.8; 95% CI, 2.2–15.1), and hyperbilirubinemia (odds ratio, 9.1; 95% CI, 2.6–31.8) were associated with increased odds of in-hospital mortality.
Conclusions: Extracorporeal membrane oxygenation can be used effectively in adults with myocarditis to support the circulation while awaiting myocardial recovery. Early extracorporeal membrane oxygenation deployment prior to cardiac arrest may be associated with better outcomes.
Le sommeil du patient en réanimation…
Sleep is an important physiologic process, and lack of sleep is associated with a host of adverse outcomes. Basic and clinical research has documented the important role circadian rhythm plays in biologic function. Critical illness is a time of extreme vulnerability for patients, and the important role sleep may play in recovery for intensive care unit (ICU) patients is just beginning to be explored. This concise clinical review focuses on the current state of research examining sleep in critical illness. We discuss sleep and circadian rhythm abnormalities that occur in ICU patients and the challenges to measuring alterations in circadian rhythm in critical illness and review methods to measure sleep in the ICU, including polysomnography, actigraphy, and questionnaires. We discuss data on the impact of potentially modifiable disruptors to patient sleep, such as noise, light, and patient care activities, and report on potential methods to improve sleep in the setting of critical illness. Finally, we review the latest literature on sleep disturbances that persist or develop after critical illness.
