La Biblio du Mois : Septembre 2015
La voilà, la Biblio de la rentrée 2015-2016, chargée mais pleine d’articles intéressants en particulier les résultats des études sur les complications liées aux cathéters centraux (PHRC 3Sites et Etude CLEAN), le début de la fin du relais AVK péri-opératoire dans les FA et surtout une étude sur les intubations par les Jeunes Anesthésistes Réanimateurs versus Senior (à ressortir auprès des plus anciens ?).
Bonne lecture !
Relais AVK en péri opératoire chez les patients ayant une FA : un changement de paradigme?
Complications liées à la pose de Cathéter Veineux Central selon le site d’insertion : Protocole 3Sites
Three anatomical sites are commonly used to insert central venous catheters, but insertion at each site has the potential for major complications.
In this multicenter trial, we randomly assigned nontunneled central venous catheterization in patients in the adult intensive care unit (ICU) to the subclavian, jugular, or femoral vein (in a 1:1:1 ratio if all three insertion sites were suitable [three-choice scheme] and in a 1:1 ratio if two sites were suitable [two-choice scheme]). The primary outcome measure was a composite of catheter-related bloodstream infection and symptomatic deep-vein thrombosis.
A total of 3471 catheters were inserted in 3027 patients. In the three-choice comparison, there were 8, 20, and 22 primary outcome events in the subclavian, jugular, and femoral groups, respectively (1.5, 3.6, and 4.6 per 1000 catheter-days; P=0.02). In pairwise comparisons, the risk of the primary outcome was significantly higher in the femoral group than in the subclavian group (hazard ratio, 3.5; 95% confidence interval [CI], 1.5 to 7.8; P=0.003) and in the jugular group than in the subclavian group (hazard ratio, 2.1; 95% CI, 1.0 to 4.3; P=0.04), whereas the risk in the femoral group was similar to that in the jugular group (hazard ratio, 1.3; 95% CI, 0.8 to 2.1; P=0.30). In the three-choice comparison, pneumothorax requiring chest-tube insertion occurred in association with 13 (1.5%) of the subclavian-vein insertions and 4 (0.5%) of the jugular-vein insertions.
In this trial, subclavian-vein catheterization was associated with a lower risk of bloodstream infection and symptomatic thrombosis and a higher risk of pneumothorax than jugular-vein or femoral-vein catheterization.
Corticothérapie en prévention du SIRS post-CEC ?
Whitlock et al., Lancet, 2015, DOI: http://dx.doi.org/10.1016/S0140-6736(15)00273-1
Cardiopulmonary bypass initiates a systemic inflammatory response syndrome that is associated with postoperative morbidity and mortality. Steroids suppress inflammatory responses and might improve outcomes in patients at high risk of morbidity and mortality undergoing cardiopulmonary bypass. We aimed to assess the effects of steroids in patients at high risk of morbidity and mortality undergoing cardiopulmonary bypass.
The Steroids In caRdiac Surgery (SIRS) study is a double-blind, randomised, controlled trial. We used a central computerised phone or interactive web system to randomly assign (1:1) patients at high risk of morbidity and mortality from 80 hospital or cardiac surgery centres in 18 countries undergoing cardiac surgery with the use of cardiopulmonary bypass to receive either methylprednisolone (250 mg at anaesthetic induction and 250 mg at initiation of cardiopulmonary bypass) or placebo. Patients were assigned with block randomisation with random block sizes of 2, 4, or 6 and stratified by centre. Patients aged 18 years or older were eligible if they had a European System for Cardiac Operative Risk Evaluation of at least 6. Patients were excluded if they were taking or expected to receive systemic steroids in the immediate postoperative period or had a history of bacterial or fungal infection in the preceding 30 days. Patients, caregivers, and those assessing outcomes were masked to allocation. The primary outcomes were 30-day mortality and a composite of death and major morbidity (ie, myocardial injury, stroke, renal failure, or respiratory failure) within 30 days, both analysed by intention to treat. Safety outcomes were also analysed by intention to treat.
Patients were recruited between June 21, 2007, and Dec 19, 2013. Complete 30-day data was available for all 7507 patients randomly assigned to methylprednisolone (n=3755) and to placebo (n=3752). Methylprednisolone, compared with placebo, did not reduce the risk of death at 30 days (154 [4%] vs 177 [5%] patients; relative risk [RR] 0·87, 95% CI 0·70–1·07, p=0·19) or the risk of death or major morbidity (909 [24%] vs 885 [24%]; RR 1·03, 95% CI 0·95–1·11, p=0·52). The most common safety outcomes in the methylprednisolone and placebo group were infection (465 [12%] vs 493 [13%]), surgical site infection (151 [4%] vs 151 [4%]), and delirium (295 [8%] vs 289 [8%]).
Methylprednisolone did not have a significant effect on mortality or major morbidity after cardiac surgery with cardiopulmonary bypass. The SIRS trial does not support the routine use of methylprednisolone for patients undergoing cardiopulmonary bypass.
Prévention des infections liées aux KTc par Chlorhexidine versus Bétadine : Etude CLEAN
Mimoz et al., Lancet, 2015, DOI: http://dx.doi.org/10.1016/S0140-6736(15)00244-5
Intravascular-catheter-related infections are frequent life-threatening events in health care, but incidence can be decreased by improvements in the quality of care. Optimisation of skin antisepsis is essential to prevent short-term catheter-related infections. We hypothesised that chlorhexidine–alcohol would be more effective than povidone iodine–alcohol as a skin antiseptic to prevent intravascular-catheter-related infections.
In this open-label, randomised controlled trial with a two-by-two factorial design, we enrolled consecutive adults (age ≥18 years) admitted to one of 11 French intensive-care units and requiring at least one of central-venous, haemodialysis, or arterial catheters. Before catheter insertion, we randomly assigned (1:1:1:1) patients via a secure web-based random-number generator (permuted blocks of eight, stratified by centre) to have all intravascular catheters prepared with 2% chlorhexidine–70% isopropyl alcohol (chlorhexidine–alcohol) or 5% povidone iodine–69% ethanol (povidone iodine–alcohol), with or without scrubbing of the skin with detergent before antiseptic application. Physicians and nurses were not masked to group assignment but microbiologists and outcome assessors were. The primary outcome was the incidence of catheter-related infections with chlorhexidine–alcohol versus povidone iodine–alcohol in the intention-to-treat population.
Between Oct 26, 2012, and Feb 12, 2014, 2546 patients were eligible to participate in the study. We randomly assigned 1181 patients (2547 catheters) to chlorhexidine–alcohol (594 patients with scrubbing, 587 without) and 1168 (2612 catheters) to povidone iodine–alcohol (580 patients with scrubbing, 588 without). Chlorhexidine–alcohol was associated with lower incidence of catheter-related infections (0·28 vs 1·77 per 1000 catheter-days with povidone iodine–alcohol; hazard ratio 0·15, 95% CI 0·05–0·41; p=0·0002). Scrubbing was not associated with a significant difference in catheter colonisation (p=0·3877). No systemic adverse events were reported, but severe skin reactions occurred more frequently in those assigned to chlorhexidine–alcohol (27 [3%] patients vsseven [1%] with povidone iodine–alcohol; p=0·0017) and led to chlorhexidine discontinuation in two patients.
For skin antisepsis, chlorhexidine–alcohol provides greater protection against short-term catheter-related infections than does povidone iodine–alcohol and should be included in all bundles for prevention of intravascular catheter-related infections.
Une injection de dexaméthasone n’augmente pas le risque d’infections post opératoires
Tissue oxygenation is a strong predictor of surgical site infection. Improving tissue oxygenation should thus reduce wound infection risk. Supplemental inspired oxygen can improve tissue oxygenation, but whether it reduces infection risk remains controversial. Low-dose dexamethasone is often given to reduce the risk of postoperative nausea and vomiting, but steroid-induced immunosuppression can increase infection risk. We therefore tested the hypotheses that supplemental perioperative oxygen reduces infection risk and that dexamethasone increases it.
Using a factorial design, patients having colorectal resections expected to last ≥2 h were randomly assigned to 30% (n=270) or 80% (n=285) inspired oxygen during and for 1 h after surgery, and to 4 mg intraoperative dexamethasone (n=283) or placebo (n=272). Physicians blinded to group assignments evaluated wounds postoperatively, using US Centers for Disease Control criteria.
Subject and surgical characteristics were similar among study groups. Surgical site infection incidence was similar among groups: 30% oxygen 15.6%, 80% oxygen 15.8% (P=1.00); dexamethasone 15.9%, placebo 15.4%, (P=0.91).
Supplemental oxygen did not reduce surgical site infection risk. The preponderance of clinical evidence suggests that administration of 80% supplemental inspired oxygen does not reduce infection risk. We did not observe an increased risk of surgical site infection with the use of a single low dose of dexamethasone, indicating that it can be used for nausea and vomiting prophylaxis without promoting wound infections.
Les variations tensionnelles peropératoires prédictives du delirium post opératoire chez le sujet âgé
Postoperative delirium is common in older patients. Despite its prognostic significance, the pathophysiology is incompletely understood. Although many risk factors have been identified, no reversible factors, particularly ones potentially modifiable by anaesthetic management, have been identified. The goal of this prospective cohort study was to investigate whether intraoperative hypotension was associated with postoperative delirium in older patients undergoing major non-cardiac surgery.
Study subjects were patients >65 years of age, undergoing major non-cardiac surgery, who were enrolled in an ongoing prospective observational study of the pathophysiology of postoperative delirium. Intraoperative blood pressure was measured and predefined criteria were used to define hypotension. Delirium was measured by the Confusion Assessment Method on the first two postoperative days. Data were analysed using t-tests, two-sample proportion tests and ordered logistic regression multivariable models, including correction for multiple comparisons.
Data from 594 patients with a mean age of 73.6 years (SD 6.2) were studied. Of these 178 (30%) developed delirium on day 1 and 176 (30%) on day 2. Patients developing delirium were older, more often female, had lower preoperative cognitive scores, and underwent longer operations. Relative hypotension (decreases by 20, 30, or 40%) or absolute hypotension [mean arterial pressure (MAP)<50 mm Hg] were not significantly associated with postoperative delirium, nor was the duration of hypotension (MAP<50 mm Hg). Conversely, intraoperative blood pressure variance was significantly associated with postoperative delirium.
These results showed that increased blood pressure fluctuation, not absolute or relative hypotension, was predictive of postoperative delirium.
L’intubation par un étudiant n’entraine pas plus de douleurs à la gorge que par un anesthésiste senior
Postoperative throat complications, such as sore throat and hoarseness, are frequent complications of tracheal intubation. To assess whether severity of throat complications is related to the experience of physicians performing tracheal intubation, we compared the incidence and duration of postoperative sore throat and hoarseness and patient satisfaction between tracheal intubation performed by trainees and experienced consultant anaesthetists.
This is a retrospective review of an institutional registry containing records of 21 606 patients undergoing general anaesthesia and was conducted with ethics board approval. All tracheal intubations by trainees were performed under the supervision of consultant anaesthetists. To avoid channel bias, the propensity score analysis was used to generate a set of matched cases (intubations by trainees) and controls (intubations by anaesthetists), yielding 3465 (sore throat) and 3267 (hoarseness) matched patient pairs. The incidence and sustained rate of symptoms were compared as primary outcomes. We also compared patient satisfaction with perioperative care.
After propensity score matching, there was no difference between tracheal intubation by trainees and tracheal intubation by consultant anaesthetists in the incidences of sore throat (32.9 vs 32.6%, P=0.84) or hoarseness (35.8 vs 35.2%, P=0.60). Odds ratios and 95% confidence intervals for tracheal intubation by trainees were 1.01 (0.91−1.12) for sore throat and 1.03 (0.93−1.14) for hoarseness. The rates of sustained sore throat and hoarseness over the course were low (P=0.85 and P=0.67, respectively). Hazard ratios and 95% confidence intervals for tracheal intubation by trainees were 0.99 (0.94−1.05) for sustained sore throat and 0.99 (0.93−1.05) for sustained hoarseness. Patient satisfaction did not differ between matched groups (P=0.66 and P=0.83).
Tracheal intubation by trainees under the supervision of consultant anaesthetists did not worsen the postoperative airway outcomes, such as sore throat and hoarseness.
Sun et al., Anesthesiology 9 2015, Vol.123, 515-523. doi:10.1097/ALN.0000000000000765
Intraoperative hypotension (IOH) may be associated with postoperative acute kidney injury (AKI), but the duration of hypotension for triggering harm is unclear. The authors investigated the association between varying periods of IOH with mean arterial pressure (MAP) less than 55, less than 60, and less than 65 mmHg with AKI.
The authors conducted a retrospective cohort study of 5,127 patients undergoing noncardiac surgery (2009 to 2012) with invasive MAP monitoring and length of stay of 1 or more days. Exclusion criteria were preoperative MAP less than 65 mmHg, dialysis dependence, urologic surgery, and surgical duration less than 30 min. The primary exposure was IOH. The primary outcome was AKI (50% or 0.3 mg/dl increase in creatinine) during the first 2 postoperative days. Multivariable logistic regression was used to model the exposure–outcome relationship.
AKI occurred in 324 (6.3%) patients and was associated with MAP less than 60 mmHg for 11 to 20 min and MAP less than 55 mmHg for more than 10 min in a graded fashion. The adjusted odds ratio of AKI for MAP less than 55 mmHg was 2.34 (1.35 to 4.05) for 11- to 20-min exposure and 3.53 (1.51 to 8.25) for more than 20 min. For MAP less than 60 mmHg, the adjusted odds ratio for AKI was 1.84 (1.11 to 3.06) for 11- to 20-min exposure.
In this analysis, postoperative AKI is associated with sustained intraoperative periods of MAP less than 55 and less than 60 mmHg. This study provides an impetus for clinical trials to determine whether interventions that promptly treat IOH and are tailored to individual patient physiology could help reduce the risk of AKI.
Nouvelle technique d’épuration du CO2 par électrodialyse
Zanella et al., AJRCCM 2015, Vol. 192, No. 6 (2015), pp. 719-726. doi: 10.1164/rccm.201502-0289OC
We developed an innovative, minimally invasive, highly efficient extracorporeal CO2 removal (ECCO2R) technique called respiratory electrodialysis (R-ED).
To evaluate the efficacy of R-ED in controlling ventilation compared with conventional ECCO2R technology.
Five mechanically ventilated swine were connected to a custom-made circuit optimized for R-ED, consisting of a hemofilter, a membrane lung, and an electrodialysis cell. Electrodialysis regionally modulates blood electrolyte concentration to convert bicarbonate to CO2 before entering the membrane lung, enhancing membrane lung CO2 extraction. All animals underwent three repeated experimental sequences, consisting of four steps: baseline (1 h), conventional ECCO2R (2 h), R-ED (2 h), and final NO-ECCO2R (1 h). Blood and gas flow were 250 ml/min and 10 L/min, respectively. Tidal volume was set at 8 ml/kg, and respiratory rate was adjusted to maintain arterial Pco2 at 50 mm Hg.
MEASUREMENTS AND MAIN RESULTS
During R-ED, chloride and H+ concentration increased in blood entering the membrane lung, almost doubling CO2 extraction compared with ECCO2R (112 ± 6 vs. 64 ± 5 ml/min, P < 0.001). Compared with baseline, R-ED and ECCO2R reduced minute ventilation by 50% and 27%, respectively. Systemic arterial gas analyses remained stable during the experimental phases. No major complication occurred, but there was an increase in creatinine level.
In this first in vivo application, we proved electrodialysis feasible and effective in increasing membrane lung CO2 extraction. R-ED was more effective than conventional ECCO2R technology in controlling ventilation. Further studies are warranted to assess the safety profile of R-ED, especially regarding kidney function.
La FA : un facteur prédictif de mortalité indépendant en réanimation
Atrial fibrillation has been associated with increased mortality in critically ill patients. We sought to determine whether atrial fibrillation in the ICU is an independent risk factor for death. A secondary objective was to determine if patients with new-onset atrial fibrillation have different risk factors or outcomes compared with patients with a previous history of atrial fibrillation.
Prospective observational cohort study.
Medical and general surgical ICUs in a tertiary academic medical center.
One thousand seven hundred seventy critically ill patients requiring at least 2 days in the ICU.
MEASUREMENTS AND MAIN RESULTS
Demographics, medical history, development of atrial fibrillation, fluid balance, echocardiographic findings, medication administration, and hospital mortality were collected during the first 4 days of ICU admission. Atrial fibrillation occurred in 236 patients (13%) (Any AF). Of these, 123 patients (7%) had no prior atrial fibrillation (New-onset AF) while the remaining 113 (6%) had recurrent atrial fibrillation (Recurrent AF). Any AF was associated with male gender, Caucasian race, increased age, cardiac disease, organ failures, and disease severity. Patients with Any AF had increased mortality compared with those without atrial fibrillation (31% vs 17%; p < 0.001), and Any AF was independently associated with death (odds ratio, 1.62; 95% CI, 1.14–2.29; p = 0.007) in multivariable analysis controlling for severity of illness and other confounders. The association of atrial fibrillation with death was magnified in patients without sepsis (odds ratio, 2.92; 95% CI, 1.52–5.60; p = 0.001). Treatment for atrial fibrillation had no effect on hospital mortality. New-onset AF and Recurrent AF were each associated with increased mortality. New-onset AF, but not Recurrent AF, was associated with increased diastolic dysfunction and vasopressor use and a greater cumulative positive fluid balance.
Atrial fibrillation in critical illness, whether new-onset or recurrent, is independently associated with increased hospital mortality, especially in patients without sepsis.
La ventilation protectrice chez le patient de réanimation n’ayant pas de SDRA
Neto et al., CCM 2015, doi: 10.1097/CCM.0000000000001189
Protective mechanical ventilation with low tidal volumes is standard of care for patients with acute respiratory distress syndrome. The aim of this individual patient data analysis was to determine the association between tidal volume and the occurrence of pulmonary complications in ICU patients without acute respiratory distress syndrome and the association between occurrence of pulmonary complications and outcome in these patients.
Individual patient data analysis.
ICU patients not fulfilling the consensus criteria for acute respiratory distress syndrome at the onset of ventilation.
Mechanical ventilation with low tidal volume.
MEASUREMENTS AND MAIN RESULTS
The primary endpoint was development of a composite of acute respiratory distress syndrome and pneumonia during hospital stay. Based on the tertiles of tidal volume size in the first 2 days of ventilation, patients were assigned to a “low tidal volume group” (tidal volumes≤ 7 mL/kg predicted body weight), an “intermediate tidal volume group” (> 7 and < 10 mL/kg predicted body weight), and a “high tidal volume group” (≥ 10 mL/kg predicted body weight). Seven investigations (2,184 patients) were included. Acute respiratory distress syndrome or pneumonia occurred in 23% of patients in the low tidal volume group, in 28% of patients in the intermediate tidal volume group, and in 31% of the patients in the high tidal volume group (adjusted odds ratio [low vs high tidal volume group], 0.72; 95% CI, 0.52–0.98; p = 0.042). Occurrence of pulmonary complications was associated with a lower number of ICU-free and hospital-free days and alive at day 28 (10.0 ± 10.9 vs 13.8 ± 11.6 d; p < 0.01 and 6.1 ± 8.1 vs 8.9 ± 9.4 d; p < 0.01) and an increased hospital mortality (49.5% vs 35.6%; p < 0.01).
Ventilation with low tidal volumes is associated with a lower risk of development of pulmonary complications in patients without acute respiratory distress syndrome.