Biblio du Mois: Février 2015

19 février 2015Formation • La Biblio du mois

Dans La Biblio du Mois, de la nouveauté d’abord puisque les AFAR se scindent désormais en deux revues (pour plus d’info):

• Anesthésie & Réanimation (ANREA), publiée en langue française les mois impairs, sera tournée vers la mise au point, la formation continue et servira de support écrit aux conférences de la SFAR.
• Anesthesia Critical Care & Pain Medicine (ACCPM), publiée en anglais les mois pairs, sera dédiée aux articles originaux.

Et toujours plus d’articles: un point de plus pour les tentatives quotidiennes de sevrage ventilatoire et de sédation, un point de moins pour la toilette quotidienne à la chlorhexidine, de la chirurgie cardio-vasculaire, de l’obstétrique… et une belle revue du NEJM (encore) sur l’acide-cétose diabétique. 

Profitez de cette nouvelle mouture de La Biblio du Mois et bonne lecture !

Comparaison entre un ratio 1-1-1 et 1-1-2 (PFC-Plaquettes-CGR) pour la transfusion massive du polytraumatisé

Evaluation d’un protocole de sédation en Réanimation Pédiatrique

Importance  Protocolized sedation improves clinical outcomes in critically ill adults, but its effect in children is unknown.

Objective  To determine whether critically ill children managed with a nurse-implemented, goal-directed sedation protocol experience fewer days of mechanical ventilation than patients receiving usual care.

Design, Setting, and Participants  Cluster randomized trial conducted in 31 US pediatric intensive care units (PICUs). A total of 2449 children (mean age, 4.7 years; range, 2 weeks to 17 years) mechanically ventilated for acute respiratory failure were enrolled in 2009-2013 and followed up until 72 hours after opioids were discontinued, 28 days, or hospital discharge.

Intervention  Intervention PICUs (17 sites; n = 1225 patients) used a protocol that included targeted sedation, arousal assessments, extubation readiness testing, sedation adjustment every 8 hours, and sedation weaning. Control PICUs (14 sites; n = 1224 patients) managed sedation per usual care.

Main Outcomes and Measures  The primary outcome was duration of mechanical ventilation. Secondary outcomes included time to recovery from acute respiratory failure, duration of weaning from mechanical ventilation, neurological testing, PICU and hospital lengths of stay, in-hospital mortality, sedation-related adverse events, measures of sedative exposure (wakefulness, pain, and agitation), and occurrence of iatrogenic withdrawal.

Results  Duration of mechanical ventilation was not different between the 2 groups (intervention: median, 6.5 [IQR, 4.1-11.2] days; control: median, 6.5 [IQR, 3.7-12.1] days). Sedation-related adverse events including inadequate pain and sedation management, clinically significant iatrogenic withdrawal, and unplanned endotracheal tube/invasive line removal were not significantly different between the 2 groups. Intervention patients experienced more postextubation stridor (7% vs 4%; P = .03) and fewer stage 2 or worse immobility-related pressure ulcers (<1% vs 2%; P = .001). In exploratory analyses, intervention patients had fewer days of opioid administration (median, 9 [IQR, 5-15] days vs 10 [IQR, 4-21] days; P = .01), were exposed to fewer sedative classes (median, 2 [IQR, 2-3] classes vs 3 [IQR, 2-4] classes; P < .001), and were more often awake and calm while intubated (median, 86% [IQR, 67%-100%] of days vs 75% [IQR, 50%-100%] of days; P = .004) than control patients, respectively; however, intervention patients had more days with any report of a pain score ≥4 (median, 50% [IQR, 27%-67%] of days vs 23% [IQR, 0%-46%] of days; P < .001) and any report of agitation (median, 60% [IQR, 33%-80%] vs 40% [IQR, 13%-67%]; P = .003), respectively.

Conclusions and Relevance  Among children undergoing mechanical ventilation for acute respiratory failure, the use of a sedation protocol compared with usual care did not reduce the duration of mechanical ventilation. Exploratory analyses of secondary outcomes suggest a complex relationship among wakefulness, pain, and agitation.

Toilette quotidienne à la chlorhexidine et prévention des infections nosocomiales en Réanimation

Importance  Daily bathing of critically ill patients with the broad-spectrum, topical antimicrobial agent chlorhexidine is widely performed and may reduce health care–associated infections.

Objective  To determine if daily bathing of critically ill patients with chlorhexidine decreases the incidence of health care–associated infections.

Design, Setting, and Participants  A pragmatic cluster randomized, crossover study of 9340 patients admitted to 5 adult intensive care units of a tertiary medical center in Nashville, Tennessee, from July 2012 through July 2013.

Interventions  Units performed once-daily bathing of all patients with disposable cloths impregnated with 2% chlorhexidine or nonantimicrobial cloths as a control. Bathing treatments were performed for a 10-week period followed by a 2-week washout period during which patients were bathed with nonantimicrobial disposable cloths, before crossover to the alternate bathing treatment for 10 weeks. Each unit crossed over between bathing assignments 3 times during the study.

Main Outcomes and Measures  The primary prespecified outcome was a composite of central line–associated bloodstream infections (CLABSIs), catheter-associated urinary tract infections (CAUTIs), ventilator-associated pneumonia (VAP), and Clostridium difficile infections. Secondary outcomes included rates of clinical cultures that tested positive for multidrug-resistant organisms, blood culture contamination, health care–associated bloodstream infections, and rates of the primary outcome by ICU.

Results  During the chlorhexidine bathing period, 55 infections occurred: 4 CLABSI, 21 CAUTI, 17 VAP, and 13 C difficile. During the control bathing period, 60 infections occurred: 4 CLABSI, 32 CAUTI, 8 VAP, and 16 C difficile. The primary outcome rate was 2.86 per 1000 patient-days during the chlorhexidine and 2.90 per 1000 patient-days during the control bathing periods (rate difference, −0.04; 95% CI, −1.10 to 1.01; P = .95). After adjusting for baseline variables, no difference between groups in the rate of the primary outcome was detected. Chlorhexidine bathing did not change rates of infection-related secondary outcomes including hospital-acquired bloodstream infections, blood culture contamination, or clinical cultures yielding multidrug-resistant organisms. In a prespecified subgroup analysis, no difference in the primary outcome was detected in any individual intensive care unit.

Conclusion and Relevance  In this pragmatic trial, daily bathing with chlorhexidine did not reduce the incidence of health care–associated infections including CLABSIs, CAUTIs, VAP, or C difficile. These findings do not support daily bathing of critically ill patients with chlorhexidine.

Traitment de l’HTA pendant la grossesse

BACKGROUND The effects of less-tight versus tight control of hypertension on pregnancy complications are unclear.

METHODS We performed an open, international, multicenter trial involving women at 14 weeks 0 days to 33 weeks 6 days of gestation who had nonproteinuric preexisting or gestational hypertension, office diastolic blood pressure of 90 to 105 mm Hg (or 85 to 105 mm Hg if the woman was taking antihypertensive medications), and a live fetus. Women were randomly assigned to less-tight control (target diastolic blood pressure, 100 mm Hg) or tight control (target diastolic blood pressure, 85 mm Hg). The composite primary outcome was pregnancy loss or high-level neonatal care for more than 48 hours during the first 28 postnatal days. The secondary outcome was serious maternal complications occurring up to 6 weeks post partum or until hospital discharge, whichever was later. 

RESULTS Included in the analysis were 987 women; 74.6% had preexisting hypertension. The primary-outcome rates were similar among 493 women assigned to less-tight control and 488 women assigned to tight control (31.4% and 30.7%, respectively; adjusted odds ratio, 1.02; 95% confidence interval [CI], 0.77 to 1.35), as were the rates of serious maternal complications (3.7% and 2.0%, respectively; adjusted odds ratio, 1.74; 95% CI, 0.79 to 3.84), despite a mean diastolic blood pressure that was higher in the less-tight-control group by 4.6 mm Hg (95% CI, 3.7 to 5.4). Severe hypertension (≥160/110 mm Hg) developed in 40.6% of the women in the less-tight-control group and 27.5% of the women in the tight-control group (P<0.001). 

CONCLUSIONS We found no significant between-group differences in the risk of pregnancy loss, high-level neonatal care, or overall maternal complications, although less-tight control was associated with a significantly higher frequency of severe maternal hypertension. 

La belle revue du NEJM sur l’acido-cétose diabétique

Endartériectomie vs stenting pour les sténoses carotidiennes symptomatiques

Background Stenting is an alternative to endarterectomy for treatment of carotid artery stenosis, but long-term efficacy is uncertain. We report long-term data from the randomised International Carotid Stenting Study comparison of these treatments. 

Methods Patients with symptomatic carotid stenosis were randomly assigned 1:1 to open treatment with stenting or endarterectomy at 50 centres worldwide. Randomisation was computer generated centrally and allocated by telephone call or fax. Major outcomes were assessed by an independent endpoint committee unaware of treatment assignment. The primary endpoint was fatal or disabling stroke in any territory after randomisation to the end of follow-up. Analysis was by intention to treat ([ITT] all patients) and per protocol from 31 days after treatment (all patients in whom assigned treatment was completed). Functional ability was rated with the modified Rankin scale. This study is registered, number ISRCTN25337470. 

Findings 1713 patients were assigned to stenting (n=855) or endarterectomy (n=858) and followed up for a median of 4·2 years (IQR 3·0–5·2, maximum 10·0). Three patients withdrew immediately and, therefore, the ITT population comprised 1710 patients. The number of fatal or disabling strokes (52 vs 49) and cumulative 5-year risk did not differ significantly between the stenting and endarterectomy groups (6·4% vs 6·5%; hazard ratio [HR] 1·06, 95% CI 0·72–1·57, p=0·77). Any stroke was more frequent in the stenting group than in the endarterectomy group (119 vs 72 events; ITT population, 5-year cumulative risk 15·2% vs 9·4%, HR 1·71, 95% CI 1·28–2·30, p<0·001; per-protocol population, 5-year cumulative risk 8·9% vs 5·8%, 1·53, 1·02–2·31, p=0·04), but were mainly non-disabling strokes. The distribution of modified Rankin scale scores at 1 year, 5 years, or final follow-up did not differ significantly between treatment groups. 

Interpretation Long-term functional outcome and risk of fatal or disabling stroke are similar for stenting and endarterectomy for symptomatic carotid stenosis.

Natrémie et fonction rénale en postop de chirurgie cardiaque

Background: The effect of urinary alkalinization in cardiac surgery patients at risk of acute kidney injury (AKI) is controversial and trial findings conflicting. Accordingly, the authors performed a prospectively planned individual patient data meta-analysis of the double-blind randomized trials in this field.

Methods: The authors studied 877 patients from three double-blind, randomized controlled trials enrolled to receive either 24 h of intravenous infusion of sodium bicarbonate or sodium chloride. The primary outcome measure was a postoperative increase in serum creatinine concentration of greater than 25% or 0.5 mg/dl (> 44 μm/L) within the first five postoperative days. Secondary outcomes included the raw change in serum creatinine, greater than 50% and greater than 100% rises in serum creatinine, developing AKI (Acute Kidney Injury Network criteria), initiation of renal replacement therapy, morbidity, and mortality.

Results: Patients were similar in demographics, comorbidities, and cardiac procedures. Sodium bicarbonate increased plasma bicarbonate (P < 0.001) and urine pH (P < 0.001). There were no differences in the development of the primary outcome (Bicarbonate 45% [39–51%] vs. Saline 42% [36–48%], P = 0.29). This result remained unchanged when controlling for study and covariates (odds ratio [OR], 99% confidence interval [CI]: Bicarbonate vs. Control, 1.11 [0.77–1.60], P = 0.45). There was, however, a significant study-adjusted benefit in elective coronary artery bypass surgery patients in terms of renal replacement therapy (Bicarbonate vs. Control, OR: 0.38 [99% CI: 0.25–0.58], P < 0.0001) and the development of an Acute Kidney Injury Network grade = 3 (Bicarbonate vs. Control, OR: 0.45 [99% CI: 0.43–0.48], P < 0.0001).

Conclusions: Urinary alkalinization using sodium bicarbonate infusion is not associated with an overall lower incidence of AKI; however, it reduces severe AKI and need for renal replacement therapy in elective coronary artery bypass patients.

Bupi/Fenta versus Fenta seul pour l’analgésie péridurale au cours du travail obstétrical 

Background: The purpose of this prospective, double-blinded, parallel-arm, randomized trial was to examine the effects of epidural bupivacaine on the length of the second stage of labor in nulliparous women.

Methods: The authors assessed length of second-stage labor, degree of motor blockade, mode of delivery, and visual analog scores in 310 nulliparous women with labor epidurals randomized to receive either: (1) 0.125% bupivacaine and fentanyl 2 μg/ml or (2) fentanyl 10 μg/ml alone via epidural using double blinding.

Results: The median duration of the second stage was 75 min (41, 128) in the bupivacaine/fentanyl group versus 73 min (42, 120) in the fentanyl-only group (P = 0.17) with a median difference of 6.0 (95% CI, −6.0 to 18.0). Furthermore, there was no difference in degree of motor blockade, incidence of operative delivery, visual analog scores, or neonatal outcomes between the two groups. No adverse events were reported.

Conclusions: Use of epidural bupivacaine/fentanyl or a fentanyl-only infusion during the second stage of labor did not affect the duration of the second stage of labor, degree of motor blockade, mode of delivery, pain relief, and maternal or neonatal outcomes. However, in the fentanyl-only infusion group, there was a fivefold increase in opioid exposure to the fetus with unknown effects on neurobehavior, an outcome not assessed beyond the immediate postnatal period in this study.

Curare et choc anaphylactique

Background: Intraoperative anaphylaxis is a rare but serious occurrence, often triggered by neuromuscular-blocking drugs (NMBDs). Previous reports suggest that the rates of anaphylaxis may be greater for rocuronium than for other NMBDs, but imprecise surrogate metrics for new patient exposures to NMBDs complicate interpretation.

Methods: This was a retrospective, observational cohort study of intraoperative anaphylaxis to NMBDs at two hospitals between 2006 and 2012. Expert anesthetic and immunologist collaborators investigated all referred cases of intraoperative anaphylaxis where NMBDs were administered and identified those where a NMBD was considered responsible. New patient exposures for each NMBD were extracted from electronic anesthetic records compiled during the same period. Anaphylaxis rates were calculated for each NMBD using diagnosed anaphylaxis cases as the numerator and the number of new patient exposures as the denominator.

Results: Twenty-one patients were diagnosed with anaphylaxis to an NMBD. The incidence of anaphylaxis was 1 in 22,451 new patient exposures for atracurium, 1 in 2,080 for succinylcholine, and 1 in 2,499 for rocuronium (P < 0.001).

Conclusions: In Auckland, the rate of anaphylaxis to succinylcholine and rocuronium is approximately 10-fold higher than to atracurium. Previous estimates of NMBD anaphylaxis rates are potentially confounded by inaccurate proxies of new patient exposures. This is the first study to report anaphylaxis rates using a hard denominator of new patient exposures obtained directly from anesthetic records.

Une revue sur le pré-conditionnement, avec un peu de physiopath ! 

Reperfusion of tissues subjected to prolonged ischaemia results in ischaemic/reperfusion injury. Fortunately, there are strategies that can be applied to attenuate this injury. These include ischaemic pre- and post-conditioning; both have been shown experimentally to reduce ischaemic/reperfusion injury by up to 75%. The molecular mechanisms of ischaemic conditioning involve the activation of surface G-protein-coupled receptors for adenosine, bradykinin, opioids, and cannabinoids. These in turn stimulate growth receptors which then trigger the activation of cytoprotective pathways resulting in a reduction in apoptosis via the mitogen-activated protein kinase/extracellular-signal regulated kinase 1/2 kinase route and a reduction in opening of mitochondrial permeability transition pores (mPTPs) via the phosphatidylinositol 3-kinase pathway. Opening of mPTPs can cause cell death. Recently, activated surface tumour necrosis factor-α receptors have been shown to also contribute to cytoprotection by activating the Janus kinase and the signal transducer and activating factor of transcription-3 pathway. Research into the mechanisms of ischaemic conditioning is still ongoing and hopefully, with the better understanding of this phenomenon, new therapeutic strategies, with possible translation into meaningful clinical trials, will be developed to reduce ischaemic/reperfusion injury.

 

Si vous vous demandiez ce que les survivants du choc septique deviennent…

Severe shock is a life-threatening condition with very high short-term mortality. Whether the long-term outcomes among survivors of severe shock are similar to long-term outcomes of other critical illness survivors is unknown. We therefore sought to assess long-term survival and functional outcomes among 90-day survivors of severe shock and determine whether clinical predictors were associated with outcomes. Seventy-six patients who were alive 90 days after severe shock (received ≥1 μg/kg per minute of norepinephrine equivalent) were eligible for the study. We measured 3-year survival and long-term functional outcomes using the Medical Outcomes Study 36-Item Short-Form Health Survey, the EuroQOL 5-D-3L, the Hospital Anxiety and Depression Scale, the Impact of Event Scale-Revised, and an employment instrument. We also assessed the relationship between in-hospital predictors and long-term outcomes. The mean long-term survival was 5.1 years; 82% (62 of 76) of patients survived, of whom 49 were eligible for follow-up. Patients who died were older than patients who survived. Thirty-six patients completed a telephone interview a mean of 5 years after hospital admission. The patients’ Physical Functioning scores were below US population norms (P < 0.001), whereas mental health scores were similar to population norms. Nineteen percent of the patients had symptoms of depression, 39% had symptoms of anxiety, and 8% had symptoms of posttraumatic stress disorder. Thirty-six percent were disabled, and 17% were working full-time. Early survivors of severe shock had a high 3-year survival rate. Patients’ long-term physical and psychological outcomes were similar to those reported for cohorts of less severely ill intensive care unit survivors. Anxiety and depression were relatively common, but only a few patients had symptoms of posttraumatic stress disorder. This study supports the observation that acute illness severity does not determine long-term outcomes. Even extremely critically ill patients have similar outcomes to general intensive care unit survivor populations.

Facteurs de risques d’échec de la thromboprophylaxie veineuse en réanimation

Objectives: To identify risk factors for failure of anticoagulant thromboprophylaxis in critically ill patients in the ICU.

Design: Multivariable regression analysis of thrombosis predictors from a randomized thromboprophylaxis trial.

Setting: Sixty-seven medical-surgical ICUs in six countries.

Patients: Three thousand seven hundred forty-six medical-surgical critically ill patients.

Interventions: All patients received anticoagulant thromboprophylaxis with low-molecular-weight heparin or unfractionated heparin at standard doses.

Measurements and Main Results: Independent predictors for venous thromboembolism, proximal leg deep vein thrombosis, and pulmonary embolism developing during critical illness were assessed. A total of 289 patients (7.7%) developed venous thromboembolism. Predictors of thromboprophylaxis failure as measured by development of venous thromboembolism included a personal or family history of venous thromboembolism (hazard ratio, 1.64; 95% CI, 1.03–2.59; p = 0.04) and body mass index (hazard ratio, 1.18 per 10-point increase; 95% CI, 1.04–1.35; p = 0.01). Increasing body mass index was also a predictor for developing proximal leg deep vein thrombosis (hazard ratio, 1.25; 95% CI, 1.06–1.46; p = 0.007), which occurred in 182 patients (4.9%). Pulmonary embolism occurred in 47 patients (1.3%) and was associated with body mass index (hazard ratio, 1.37; 95% CI, 1.02–1.83; p = 0.035) and vasopressor use (hazard ratio, 1.84; 95% CI, 1.01–3.35; p = 0.046). Low-molecular-weight heparin (in comparison to unfractionated heparin) thromboprophylaxis lowered pulmonary embolism risk (hazard ratio, 0.51; 95% CI, 0.27–0.95; p = 0.034) while statin use in the preceding week lowered the risk of proximal leg deep vein thrombosis (hazard ratio, 0.46; 95% CI, 0.27–0.77; p = 0.004).

Conclusions: Failure of standard thromboprophylaxis using low-molecular-weight heparin or unfractionated heparin is more likely in ICU patients with elevated body mass index, those with a personal or family history of venous thromboembolism, and those receiving vasopressors. Alternate management or incremental risk reduction strategies may be needed in such patients.

Arrêt quotidien des sédations et tentative de ventilation spontanée quotidienne diminuent les évènements associés à la ventilation

Rationale: The CDC introduced ventilator-associated event (VAE) definitions in January 2013. Little is known about VAE prevention. We hypothesized that daily, coordinated spontaneous awakening trials (SATs) and spontaneous breathing trials (SBTs) might prevent VAEs. 

Objectives: To assess the preventability of VAEs. 

Methods: We nested a multicenter quality improvement collaborative within a prospective study of VAE surveillance among 20 intensive care units between November 2011 and May 2013. Twelve units joined the collaborative and implemented an opt-out protocol for nurses and respiratory therapists to perform paired daily SATs and SBTs. The remaining eight units conducted surveillance alone. We measured temporal trends in VAEs using generalized mixed effects regression models adjusted for patient-level unit, age, sex, reason for intubation, Sequential Organ Failure Assessment score, and comorbidity index. 

Measurements and Main Results: We tracked 5,164 consecutive episodes of mechanical ventilation: 3,425 in collaborative units and 1,739 in surveillance-only units. Within collaborative units, significant increases in SATs, SBTs, and percentage of SBTs performed without sedation were mirrored by significant decreases in duration of mechanical ventilation and hospital length-of-stay. There was no change in VAE risk per ventilator day but significant decreases in VAE risk per episode of mechanical ventilation (odds ratio [OR], 0.63; 95% confidence interval [CI], 0.42–0.97) and infection-related ventilator-associated complications (OR, 0.35; 95% CI, 0.17–0.71) but not pneumonias (OR, 0.51; 95% CI, 0.19–1.3). Within surveillance-only units, there were no significant changes in SAT, SBT, or VAE rates. 

Conclusions: Enhanced performance of paired, daily SATs and SBTs is associated with lower VAE rates.