Liberal or Restrictive Transfusion Strategy in Patients with Traumatic Brain Injury.

BACKGROUND: The effect of a liberal transfusion strategy as compared with a restrictive strategy on outcomes in critically ill patients with traumatic brain injury is unclear. METHODS: We randomly assigned adults with moderate or severe traumatic brain injury and anemia to receive transfusion of red cells according to a liberal strategy (transfusions initiated at a hemoglobin level of ≤10 g per deciliter) or a restrictive strategy (transfusions initiated at ≤7 g per deciliter). The primary outcome was an unfavorable outcome as assessed by the score on the Glasgow Outcome Scale-Extended at 6 months, which we categorized with the use of a sliding dichotomy that was based on the prognosis of each patient at baseline. Secondary outcomes included mortality, functional independence, quality of life, and depression at 6 months. RESULTS: A total of 742 patients underwent randomization, with 371 assigned to each group. The analysis of the primary outcome included 722 patients. The median hemoglobin level in the intensive care unit was 10.8 g per deciliter in the group assigned to the liberal strategy and 8.8 g per deciliter in the group assigned to the restrictive strategy. An unfavorable outcome occurred in 249 of 364 patients (68.4%) in the liberal-strategy group and in 263 of 358 (73.5%) in the restrictive-strategy group (adjusted absolute difference, restrictive strategy vs. liberal strategy, 5.4 percentage points; 95% confidence interval, -2.9 to 13.7). Among survivors, a liberal strategy was associated with higher scores on some but not all the scales assessing functional independence and quality of life. No association was observed between the transfusion strategy and mortality or depression. Venous thromboembolic events occurred in 8.4% of the patients in each group, and acute respiratory distress syndrome occurred in 3.3% and 0.8% of patients in the liberal-strategy and restrictive-strategy groups, respectively. CONCLUSIONS: In critically ill patients with traumatic brain injury and anemia, a liberal transfusion strategy did not reduce the risk of an unfavorable neurologic outcome at 6 months. (Funded by the Canadian Institutes of Health Research and others; HEMOTION ClinicalTrials.gov number, NCT03260478.).

Intravenous Vitamin C in Adults with Sepsis in the Intensive Care Unit.

BACKGROUND: Studies that have evaluated the use of intravenous vitamin C in adults with sepsis who were receiving vasopressor therapy in the intensive care unit (ICU) have shown mixed results with respect to the risk of death and organ dysfunction. METHODS: In this randomized, placebo-controlled trial, we assigned adults who had been in the ICU for no longer than 24 hours, who had proven or suspected infection as the main diagnosis, and who were receiving a vasopressor to receive an infusion of either vitamin C (at a dose of 50 mg per kilogram of body weight) or matched placebo administered every 6 hours for up to 96 hours. The primary outcome was a composite of death or persistent organ dysfunction (defined by the use of vasopressors, invasive mechanical ventilation, or new renal-replacement therapy) on day 28. RESULTS: A total of 872 patients underwent randomization (435 to the vitamin C group and 437 to the control group). The primary outcome occurred in 191 of 429 patients (44.5%) in the vitamin C group and in 167 of 434 patients (38.5%) in the control group (risk ratio, 1.21; 95% confidence interval [CI], 1.04 to 1.40; P = 0.01). At 28 days, death had occurred in 152 of 429 patients (35.4%) in the vitamin C group and in 137 of 434 patients (31.6%) in the placebo group (risk ratio, 1.17; 95% CI, 0.98 to 1.40) and persistent organ dysfunction in 39 of 429 patients (9.1%) and 30 of 434 patients (6.9%), respectively (risk ratio, 1.30; 95% CI, 0.83 to 2.05). Findings were similar in the two groups regarding organ-dysfunction scores, biomarkers, 6-month survival, health-related quality of life, stage 3 acute kidney injury, and hypoglycemic episodes. In the vitamin C group, one patient had a severe hypoglycemic episode and another had a serious anaphylaxis event. CONCLUSIONS: In adults with sepsis receiving vasopressor therapy in the ICU, those who received intravenous vitamin C had a higher risk of death or persistent organ dysfunction at 28 days than those who received placebo. (Funded by the Lotte and John Hecht Memorial Foundation; LOVIT ClinicalTrials.gov number, NCT03680274.).

Transbronchial Lung Cryobiopsies, Transbronchial Forceps Lung Biopsies, and Surgical Lung Biopsies in Mechanically Ventilated Patients with Acute Hypoxemic Respiratory Failure: A Retrospective Cohort Study.

IMPORTANCE: Lung biopsies are sometimes performed in mechanically ventilated patients with acute hypoxemic respiratory failure (AHRF) of unknown etiology to guide patient management. While surgical lung biopsies (SLB) offer high diagnostic rates, they may also cause significant complications. Transbronchial forceps lung biopsies (TBLB) are less invasive but often produce non-contributive specimens. Transbronchial lung cryobiopsies (TBLC) yield specimens of potentially better quality than TBLB, but due to their novel implementation in the intensive care unit (ICU), their accuracy and safety are still unclear. OBJECTIVES: Our main objective was to evaluate the risk of adverse events in patients with AHRF following the three biopsy techniques. Our secondary objectives were to assess the diagnostic yield and associated modifications of patient management of each technique. DESIGN, SETTINGS AND PARTICIPANTS: We conducted a retrospective cohort study comparing TBLC, TBLB, and SLB in mechanically ventilated patients with AHRF. MAIN OUTCOMES AND MEASURES: The primary outcome was the proportion of patients with at least one complication, and secondary outcomes included complication rates, diagnostic yields, treatment modifications, and mortality. RESULTS: Of the 26 patients who underwent lung biopsies from 2018 to 2022, all TBLC and SLB patients and 60% of TBLB patients had at least one complication. TBLC patients had higher unadjusted numbers of total and severe complications, but also worse Sequential Organ Failure Assessment scores and P/F ratios. A total of 25 biopsies (25/26, 96%) provided histopathological diagnoses, 88% (22/25) of which contributed to patient management. ICU mortality was high for all modalities (63% for TBLC, 60% for TBLB and 50% for SLB). CONCLUSIONS AND RELEVANCE: All biopsy methods had high diagnostic yields and the great majority contributed to patient management; however, complication rates were elevated. Further research is needed to determine which patients may benefit from lung biopsies and to determine the best biopsy modality.

Physicians' beliefs and perceived importance of traumatic brain injury-associated agitation in critically ill patients: a survey of Canadian intensivists.

PURPOSE: Agitation is a common behavioural problem following traumatic brain injury (TBI). Intensive care unit (ICU) physicians' perspectives regarding TBI-associated agitation are unknown. Our objective was to describe physicians' beliefs and perceived importance of TBI-associated agitation in critically ill patients. METHODS: Following current standard guidance, we built an electronic, self-administrated, 42-item survey, pretested it for reliability and validity, and distributed it to 219 physicians working in 18 ICU level-1 trauma centres in Canada. We report the results using descriptive statistics. RESULTS: The overall response rate was 93/219 (42%), and 76/93 (82%) respondents completed the full survey. Most respondents were men with ten or more years of experience. Respondents believed that pre-existing dementia (90%) and regular recreational drug use (86%) are risk factors for agitation. Concerning management, 91% believed that the use of physical restraints could worsen agitation, 90% believed that having family at the bedside reduces agitation, and 72% believed that alpha-2 adrenergic agonists are efficacious for managing TBI agitation. Variability was observed in beliefs on epidemiology, sex, gender, age, socioeconomic status, and other pharmacologic options. Respondents considered TBI agitation frequent enough to justify the implementation of management protocols (87%), perceived the current level of clinical evidence on TBI agitation management to be insufficient (84%), and expressed concerns about acute and long-term detrimental outcomes and burden to patients, health care professionals, and relatives (85%). CONCLUSION: Traumatic brain injury-associated agitation in critically ill patients was perceived as an important issue for most ICU physicians. Physicians agreed on multiple approaches to manage TBI-associated agitation although agreement on epidemiology and risk factors was variable.

RéSUMé: OBJECTIF: L'agitation est un problème de comportement courant à la suite d'un traumatisme crânien (TC). Le point de vue des médecins des unités de soins intensifs (USI) sur l'agitation associée aux traumatismes crâniens est inconnu. Notre objectif était de décrire les croyances et l'importance perçue par les médecins de l'agitation associée aux traumatismes crâniens chez les patient·es gravement malades. MéTHODE: Conformément aux lignes directrices standard actuelles, nous avons élaboré un sondage électronique auto-administré de 42 questions, l'avons testé au préalable pour en vérifier la fiabilité et la validité, et l'avons distribué à 219 médecins travaillant dans les USI de 18 centres de traumatologie de niveau 1 au Canada. Les résultats sont présentés à l'aide de statistiques descriptives. RéSULTATS: Le taux de réponse global a été de 93 sur 219 (42 %) et 76 sur 93 (82 %) personnes interrogées ont répondu à l'ensemble du sondage. La plupart des répondant·es étaient des hommes comptant dix ans ou plus d'expérience. Les répondant·es sont d'avis que la démence préexistante (90 %) et la consommation régulière de drogues à des fins récréatives (86 %) sont des facteurs de risque d'agitation. En ce qui concerne la prise en charge, 91 % des répondant·es estiment que l'utilisation de contentions physiques peut aggraver l'agitation, 90 % croient que le fait d'avoir de la famille au chevet du patient ou de la patiente réduit l'agitation et 72 % pensent que les agonistes alpha-2 adrénergiques sont efficaces pour gérer l'agitation causée par les traumatismes crâniens. Une variabilité a été observée dans les croyances concernant l'épidémiologie, le sexe, le genre, l'âge, le statut socio-économique et d'autres options pharmacologiques. Les répondant·es considéraient que l'agitation liée aux traumatismes crâniens était suffisamment fréquente pour justifier la mise en œuvre de protocoles de prise en charge (87 %), estimaient que le niveau actuel de données probantes cliniques sur la prise en charge de l'agitation causée par un traumatisme crânien était insuffisant (84 %), et se sont dit·es préoccupé·es par les conséquences préjudiciables aiguës et à long terme et par le fardeau pour les patient·es, les professionnel·les de la santé et les proches (85 %). CONCLUSION: L'agitation associée à un traumatisme crânien chez les patient·es gravement malades était perçue comme un problème important pour la plupart des médecins des soins intensifs. Les médecins s'entendaient sur plusieurs approches pour gérer l'agitation associée aux traumatismes crâniens, bien que l'accord sur l'épidémiologie et les facteurs de risque était variable.

Implication of Hypotension in the Pathogenesis of Cognitive Impairment and Brain Injury in Chronic Liver Disease.

The incidence of chronic liver disease is on the rise. One of the primary causes of hospital admissions for patients with cirrhosis is hepatic encephalopathy (HE), a debilitating neurological complication. HE is defined as a reversible syndrome, yet there is growing evidence stating that, under certain conditions, HE is associated with permanent neuronal injury and irreversibility. The pathophysiology of HE primarily implicates a strong role for hyperammonemia, but it is believed other pathogenic factors are involved. The fibrotic scarring of the liver during the progression of chronic liver disease (cirrhosis) consequently leads to increased hepatic resistance and circulatory anomalies characterized by portal hypertension, hyperdynamic circulatory state and systemic hypotension. The possible repercussions of these circulatory anomalies on brain perfusion, including impaired cerebral blood flow (CBF) autoregulation, could be implicated in the development of HE and/or permanent brain injury. Furthermore, hypotensive insults incurring during gastrointestinal bleed, infection, or liver transplantation may also trigger or exacerbate brain dysfunction and cell damage. This review will focus on the role of hypotension in the onset of HE as well as in the occurrence of neuronal cell loss in cirrhosis.

An international RAND/UCLA expert panel to determine the optimal diagnosis and management of burn inhalation injury.

BACKGROUND: Burn inhalation injury (BII) is a major cause of burn-related mortality and morbidity. Despite published practice guidelines, no consensus exists for the best strategies regarding diagnosis and management of BII. A modified DELPHI study using the RAND/UCLA (University of California, Los Angeles) Appropriateness Method (RAM) systematically analysed the opinions of an expert panel. Expert opinion was combined with available evidence to determine what constitutes appropriate and inappropriate judgement in the diagnosis and management of BII. METHODS: A 15-person multidisciplinary panel comprised anaesthetists, intensivists and plastic surgeons involved in the clinical management of major burn patients adopted a modified Delphi approach using the RAM method. They rated the appropriateness of statements describing diagnostic and management options for BII on a Likert scale. A modified final survey comprising 140 statements was completed, subdivided into history and physical examination (20), investigations (39), airway management (5), systemic toxicity (23), invasive mechanical ventilation (29) and pharmacotherapy (24). Median appropriateness ratings and the disagreement index (DI) were calculated to classify statements as appropriate, uncertain, or inappropriate. RESULTS: Of 140 statements, 74 were rated as appropriate, 40 as uncertain and 26 as inappropriate. Initial intubation with ≥ 8.0 mm endotracheal tubes, lung protective ventilatory strategies, initial bronchoscopic lavage, serial bronchoscopic lavage for severe BII, nebulised heparin and salbutamol administration for moderate-severe BII and N-acetylcysteine for moderate BII were rated appropriate. Non-protective ventilatory strategies, high-frequency oscillatory ventilation, high-frequency percussive ventilation, prophylactic systemic antibiotics and corticosteroids were rated inappropriate. Experts disagreed (DI ≥ 1) on six statements, classified uncertain: the use of flexible fiberoptic bronchoscopy to guide fluid requirements (DI = 1.52), intubation with endotracheal tubes of internal diameter < 8.0 mm (DI = 1.19), use of airway pressure release ventilation modality (DI = 1.19) and nebulised 5000IU heparin, N-acetylcysteine and salbutamol for mild BII (DI = 1.52, 1.70, 1.36, respectively). CONCLUSIONS: Burns experts mostly agreed on appropriate and inappropriate diagnostic and management criteria of BII as in published guidance. Uncertainty exists as to the optimal diagnosis and management of differing grades of severity of BII. Future research should investigate the accuracy of bronchoscopic grading of BII, the value of bronchial lavage in differing severity groups and the effectiveness of nebulised therapies in different severities of BII.

The Suitability of Potential Organ Donors Using Real Case-Scenarios; Do we Need to Create a "Donor Board" Process for Donors Perceived as Unlikely Suitable?

Introduction: Despite availability of selection criteria, different interpretations can lead to variability in the appreciation of donor eligibility with possible viable organs missed. Our primary objective was to test the perception of feasibility of potential organ donors through the survey of a small sample of external evaluators. Methods: Clinical scenarios summarizing 66 potential donors managed in the first year of our Organ Recovery Center were sent to four critical care physicians to evaluate the feasibility of the potential donors and the probability of organ procurement. Results: Potential donors procuring at least one organ were identified in 55 of the 66 cases (83%). Unanimity was reached in 38 cases, encompassing 35 out of the 55 converted and 3 of the non-converted donors. The overall agreement was moderate (kappa = 0.60, 95% CI: 0.37-0.82). For the organs finally procured for transplantation, organ donation was predicted for the majority of the cases, but high discrepancy was present with the final outcome of organs not procured (particularly liver and kidney). Conclusion: The assessment of a potential donor is a complex dynamic process. In order to increase organ availability, standardized electronically clinical data, as well a "donor board" structure of decision might inform future systems.

The PROMIZING trial enrollment algorithm for early identification of patients ready for unassisted breathing.

BACKGROUND: Liberating patients from mechanical ventilation (MV) requires a systematic approach. In the context of a clinical trial, we developed a simple algorithm to identify patients who tolerate assisted ventilation but still require ongoing MV to be randomized. We report on the use of this algorithm to screen potential trial participants for enrollment and subsequent randomization in the Proportional Assist Ventilation for Minimizing the Duration of MV (PROMIZING) study. METHODS: The algorithm included five steps: enrollment criteria, pressure support ventilation (PSV) tolerance trial, weaning criteria, continuous positive airway pressure (CPAP) tolerance trial (0 cmH2O during 2 min) and spontaneous breathing trial (SBT): on fraction of inspired oxygen (FiO2) 40% for 30-120 min. Patients who failed the weaning criteria, CPAP Zero trial, or SBT were randomized. We describe the characteristics of patients who were initially enrolled, but passed all steps in the algorithm and consequently were not randomized. RESULTS: Among the 374 enrolled patients, 93 (25%) patients passed all five steps. At time of enrollment, most patients were on PSV (87%) with a mean (± standard deviation) FiO2 of 34 (± 6) %, PSV of 8.7 (± 2.9) cmH2O, and positive end-expiratory pressure of 6.1 (± 1.6) cmH2O. Minute ventilation was 9.0 (± 3.1) L/min with a respiratory rate of 17.4 (± 4.4) breaths/min. Patients were liberated from MV with a median [interquartile range] delay between initial screening and extubation of 5 [1-49] hours. Only 7 (8%) patients required reintubation. CONCLUSION: The trial algorithm permitted identification of 93 (25%) patients who were ready to extubate, while their clinicians predicted a duration of ventilation higher than 24 h.

A novel capnogram analysis to guide ventilation during cardiopulmonary resuscitation: clinical and experimental observations.

BACKGROUND: Cardiopulmonary resuscitation (CPR) decreases lung volume below the functional residual capacity and can generate intrathoracic airway closure. Conversely, large insufflations can induce thoracic distension and jeopardize circulation. The capnogram (CO2 signal) obtained during continuous chest compressions can reflect intrathoracic airway closure, and we hypothesized here that it can also indicate thoracic distension. OBJECTIVES: To test whether a specific capnogram may identify thoracic distension during CPR and to assess the impact of thoracic distension on gas exchange and hemodynamics. METHODS: (1) In out-of-hospital cardiac arrest patients, we identified on capnograms three patterns: intrathoracic airway closure, thoracic distension or regular pattern. An algorithm was designed to identify them automatically. (2) To link CO2 patterns with ventilation, we conducted three experiments: (i) reproducing the CO2 patterns in human cadavers, (ii) assessing the influence of tidal volume and respiratory mechanics on thoracic distension using a mechanical lung model and (iii) exploring the impact of thoracic distension patterns on different circulation parameters during CPR on a pig model. MEASUREMENTS AND MAIN RESULTS: (1) Clinical data: 202 capnograms were collected. Intrathoracic airway closure was present in 35%, thoracic distension in 22% and regular pattern in 43%. (2) Experiments: (i) Higher insufflated volumes reproduced thoracic distension CO2 patterns in 5 cadavers. (ii) In the mechanical lung model, thoracic distension patterns were associated with higher volumes and longer time constants. (iii) In six pigs during CPR with various tidal volumes, a CO2 pattern of thoracic distension, but not tidal volume per se, was associated with a significant decrease in blood pressure and cerebral perfusion. CONCLUSIONS: During CPR, capnograms reflecting intrathoracic airway closure, thoracic distension or regular pattern can be identified. In the animal experiment, a thoracic distension pattern on the capnogram is associated with a negative impact of ventilation on blood pressure and cerebral perfusion during CPR, not predicted by tidal volume per se.

A cadaveric perfused model with antegrade arteriovenous pulsatile circulation: a new tool for teaching endovascular skills.

BACKGROUND: The benefits of using cadaveric humans in surgical training are well documented, and knowledge of the latest endovascular techniques is essential in the daily practice of vascular surgeons. Our study explores the feasibility of an affordable human cadaveric model with pulsatile and heated antegrade perfusion for reliable and reproducible endovascular or surgical simulation. METHODS: We undertook cannulation of 7 human cadavers embalmed in a saturated salt solution to create a left-to-right central perfusion with a heated solution, from the ascending thoracic aorta to the right atrium. To that end, we used surgically created carotidojugular and femorofemoral arteriovenous fistulas. Biomedical engineers designed a prototype pump for pulsatile circulation. We monitored invasive blood pressure and temperature. We used this model for training for endovascular thoracic aortic procedures and open vascular surgeries. RESULTS: The prototype pump achieved a pulsatile flow rate of 4.7 L/min. Effective cadaveric perfusion was achieved for several hours, not only with an arterioarterial pathway but also with arteriovenous circulation. The arterial pressures and in situ temperatures accurately restored vascular functions for life-like conditions. This new model made it possible to successfully perform thoracic endovascular aortic repair, subclavian artery stenting and simulation of abdominal open vascular trauma management. The saturated salt solution method and a specifically designed pump improved cost competitiveness. CONCLUSION: Endovascular simulation on human cadavers, optimized with the pulsatile and heated perfusion system, can be a dynamic adjunct for surgical training and familiarization with new devices. This reproducible teaching tool could be relevant in all surgery programs.

Epidemiology of intravenous immune globulin in septic shock: a retrospective cohort analysis of the Premier Healthcare Database.

PURPOSE: Intravenous immune globulin (IVIG) may improve survival in people with septic shock. Current utilization patterns of IVIG are unknown. We sought to characterize adult patients with septic shock requiring vasopressors who received IVIG, describes IVIG regimens, and evaluate determinants of IVIG use in patients with septic shock. METHODS: We conducted a retrospective database study of adult patients with septic shock admitted to US hospitals in the Premier Healthcare Database (from July 2010 to June 2013). We described the proportion of patients with septic shock receiving IVIG, examined IVIG regimens across sites and employed random-effects multivariable regression techniques to identify predictors of IVIG use. RESULTS: Intravenous immune globulin was administered to 0.3% (n = 685) of patients with septic shock; with a median [interquartile range (IQR)] dose of 1 [0.5-1.8] g·kg-1 for a median [IQR] of 1 [1-2] day. Receipt of IVIG was less likely for Black patients (odds ratio [OR], 0.54; 95% confidence interval [CI] 0.41 to 0.72) and patients without private insurance (Medicare OR, 0.73; 95% CI 0.59 to 0.90; Medicaid OR, 0.41; 95% CI 0.30 to 0.57) and more likely for patients with immunocompromise (OR, 6.83; 95% CI 5.47 to 8.53), necrotizing fasciitis (OR, 9.78; 95% CI 6.97 to 13.72), and toxic shock (OR, 56.9; 95% CI 38.7 to 83.7). CONCLUSIONS: Intravenous immune globulin is used infrequently across the US in patients with septic shock. Regimens of IVIG in septic shock may be less intensive than those associated with a survival benefit in meta-analyses. Observed infrequent use supports apparent clinical equipoise, perhaps secondary to limitations of the primary literature. A clinical trial evaluating the role of IVIG in septic shock is needed.

RéSUMé: OBJECTIF: L'immunoglobuline intraveineuse (IGIV) peut améliorer la survie chez les personnes atteintes de choc septique. Les pratiques actuelles d'utilisation de l'IGIV sont inconnues. Nous avons cherché à caractériser les patients adultes en état de choc septique et nécessitant des vasopresseurs qui ont reçu de l'IGIV, à décrire les dosages administrés d'IGIV, et à évaluer les causes déterminantes d'une utilisation d'IGIV chez ces patients. MéTHODE: Nous avons réalisé une étude rétrospective de base de données portant sur des patients adultes atteints de choc septique admis dans des hôpitaux américains et inclus dans la base de données Premier Healthcare (de juillet 2010 à juin 2013). Nous avons décrit la proportion de patients en choc septique recevant de l'IGIV, examiné les posologies utilisées d'IGIV à travers les sites et employé des techniques de régression multivariable à effets aléatoires pour identifier les prédicteurs de l'utilisation d'IGIV. RéSULTATS: L'IGIV a été administrée à 0,3 % (n = 685) des patients présentant un choc septique, avec une dose médiane [écart interquartile (ÉIQ)] de 1 [0,5­1,8] g·kg-1 pour une médiane [ÉIQ] de 1 [1­2] jour. L'administration d'IGIV était moins probable chez les patients noirs (rapport de cotes [RC], 0,54; intervalle de confiance [IC] à 95 %, 0,41 à 0,72) et les patients sans assurance privée (RC Medicare, 0,73; IC 95 %, 0,59 à 0,90; RC Medicaid, 0,41; IC 95 %, 0,30 à 0,57) et plus probable chez les patients immunodéprimés (RC, 6,83; IC 95 %, 5,47 à 8,53), atteints de fasciite nécrosante (RC, 9,78; IC 95 %, 6,97 à 13,72), et en choc toxique (RC, 56,9; IC 95 %, 38,7 à 83,7). CONCLUSION: L'IGIV est rarement utilisée aux États-Unis chez les patients en choc septique. Les dosages d'IGIV utilisés en cas de choc septique pourraient être moins intensifs que ceux associés à un effet bénéfique en matière de survie dans les méta-analyses. L'utilisation peu fréquente observée appuie une équivalence clinique apparente, peut-être secondaire aux limites de la littérature princeps. Une étude clinique évaluant le rôle de l'IGIV dans le choc septique est nécessaire.

Intravenous immune globulin in septic shock: a Canadian national survey of critical care medicine and infectious disease specialist physicians.

PURPOSE: This national survey evaluated the perceived efficacy and safety of intravenous immune globulin (IVIG) in septic shock, self-reported utilization patterns, barriers to use, the population of interest for further trials and willingness to participate in future research of IVIG in septic shock. METHODS: We conducted a cross-sectional survey of critical care and infectious diseases physicians across Canada. We summarized categorical item responses as counts and proportions. We developed a multivariable logistic regression model to identify physician-level predictors of IVIG use in septic shock. RESULTS: Our survey was disseminated to 674 eligible respondents with a final response rate of 60%. Most (91%) respondents reported having prescribed IVIG to patients with septic shock at least once, 86% for septic shock due to necrotizing fasciitis, 52% for other bacterial toxin-mediated causes of septic shock, and 5% for undifferentiated septic shock. The majority of respondents expressed uncertainty regarding the impact of IVIG on mortality (97%) and safety (95%) in septic shock. Respondents were willing to participate in further IVIG research with 98% stating they would consider enrolling their patients into a trial of IVIG in septic shock. Familiarity with published evidence was the single greatest predictor of IVIG use in septic shock (odds ratio, 10.2; 95% confidence interval, 3.4 to 30.5; P < 0.001). CONCLUSIONS: Most Canadian critical care and infectious diseases specialist physicians reported previous experience using IVIG in septic shock. Respondents identified inadequacy of existing research as the greatest barrier to routine use of IVIG in septic shock. Most respondents support the need for further studies on IVIG in septic shock, and would consider enrolling their own patients into a trial of IVIG in septic shock.

RéSUMé: OBJECTIF : Cette enquête nationale a évalué l'efficacité et l'innocuité perçues des immunoglobulines intraveineuses (IgIV) dans le contexte du choc septique, les habitudes d'utilisation autodéclarées, les obstacles à l'utilisation de cette modalité, les populations à explorer pour des études futures et la volonté de participer aux recherches futures sur les IgIV et le choc septique. MéTHODE : Nous avons mené une enquête transversale auprès de médecins intensivistes et spécialistes des maladies infectieuses au Canada. Nous avons résumé les réponses de chaque point catégorique en tant que dénombrement et proportions. Nous avons mis au point un modèle de régression logistique multivariée afin d'identifier les prédicteurs, au niveau des médecins, d'une utilisation des IgIV en cas de choc septique. RéSULTATS : Notre sondage a été acheminé à 674 médecins admissibles et nous avons obtenu un taux de réponse final de 60 %. La plupart (91%) des répondants ont indiqué avoir prescrit des IgIV aux patients en choc septique au moins une fois, 86 % pour un choc septique dû à une fasciite nécrosante, 52 % pour des chocs septiques d'autres étiologies médiées par des toxines bactériennes, et 5 % dans des cas de choc septique non différencié. La majorité des répondants ont exprimé de l'incertitude quant à l'incidence des IgIV sur la mortalité (97 %) et l'innocuité (95 %) lors de choc septique. Les répondants étaient disposés à participer à d'autres recherches sur les IgIV, 98 % déclarant qu'ils envisageraient d'inscrire leurs patients à une étude sur les IgIV et le choc septique. La familiarité avec les données probantes publiées était le plus grand prédicteur d'utilisation d'IgIV dans un contexte de choc septique (rapport de cotes, 10,2; intervalle de confiance à 95 %, 3,4 à 30,5; P < 0,001). CONCLUSION : La plupart des médecins intensivistes et spécialistes des maladies infectieuses canadiens ont rapporté avoir une expérience antérieure d'utilisation d'IgIV en cas de choc septique. Les répondants ont identifié l'insuffisance de la recherche existante comme le plus grand obstacle à l'utilisation systématique d'IgIV dans les cas de choc septique. La plupart des répondants appuient la nécessité d'études plus approfondies sur les IgIV et le choc septique et envisageraient d'inscrire leurs propres patients à une étude sur les IgIV dans un contexte de choc septique.

Effect of Probiotics on Incident Ventilator-Associated Pneumonia in Critically Ill Patients: A Randomized Clinical Trial.

Importance: Growing interest in microbial dysbiosis during critical illness has raised questions about the therapeutic potential of microbiome modification with probiotics. Prior randomized trials in this population suggest that probiotics reduce infection, particularly ventilator-associated pneumonia (VAP), although probiotic-associated infections have also been reported. Objective: To evaluate the effect of Lactobacillus rhamnosus GG on preventing VAP, additional infections, and other clinically important outcomes in the intensive care unit (ICU). Design, Setting, and Participants: Randomized placebo-controlled trial in 44 ICUs in Canada, the United States, and Saudi Arabia enrolling adults predicted to require mechanical ventilation for at least 72 hours. A total of 2653 patients were enrolled from October 2013 to March 2019 (final follow-up, October 2020). Interventions: Enteral L rhamnosus GG (1 × 1010 colony-forming units) (n = 1321) or placebo (n = 1332) twice daily in the ICU. Main Outcomes and Measures: The primary outcome was VAP determined by duplicate blinded central adjudication. Secondary outcomes were other ICU-acquired infections including Clostridioides difficile infection, diarrhea, antimicrobial use, ICU and hospital length of stay, and mortality. Results: Among 2653 randomized patients (mean age, 59.8 years [SD], 16.5 years), 2650 (99.9%) completed the trial (mean age, 59.8 years [SD], 16.5 years; 1063 women [40.1%.] with a mean Acute Physiology and Chronic Health Evaluation II score of 22.0 (SD, 7.8) and received the study product for a median of 9 days (IQR, 5-15 days). VAP developed among 289 of 1318 patients (21.9%) receiving probiotics vs 284 of 1332 controls (21.3%; hazard ratio [HR], 1.03 (95% CI, 0.87-1.22; P = .73, absolute difference, 0.6%, 95% CI, -2.5% to 3.7%). None of the 20 prespecified secondary outcomes, including other ICU-acquired infections, diarrhea, antimicrobial use, mortality, or length of stay showed a significant difference. Fifteen patients (1.1%) receiving probiotics vs 1 (0.1%) in the control group experienced the adverse event of L rhamnosus in a sterile site or the sole or predominant organism in a nonsterile site (odds ratio, 14.02; 95% CI, 1.79-109.58; P < .001). Conclusions and Relevance: Among critically ill patients requiring mechanical ventilation, administration of the probiotic L rhamnosus GG compared with placebo, resulted in no significant difference in the development of ventilator-associated pneumonia. These findings do not support the use of L rhamnosus GG in critically ill patients. Trial Registration: ClinicalTrials.gov Identifier: NCT02462590.

Intrathoracic Airway Closure Impacts CO2 Signal and Delivered Ventilation during Cardiopulmonary Resuscitation.

RATIONALE: End-tidal CO2 (EtCO2) is used to monitor cardiopulmonary resuscitation (CPR), but it can be affected by intrathoracic airway closure. Chest compressions induce oscillations in expired CO2, and this could reflect variable degrees of airway patency. OBJECTIVES: To understand the impact of airway closure during CPR, and the relationship between the capnogram shape, airway closure, and delivered ventilation. METHODS: This study had three parts: 1) a clinical study analyzing capnograms after intubation in patients with out-of-hospital cardiac arrest receiving continuous chest compressions, 2) a bench model, and 3) experiments with human cadavers. For 2 and 3, a constant CO2 flow was added in the lung to simulate CO2 production. Capnograms similar to clinical recordings were obtained and different ventilator settings tested. EtCO2 was compared with alveolar CO2 (bench). An airway opening index was used to quantify chest compression-induced expired CO2 oscillations in all three clinical and experimental settings. MEASUREMENTS AND MAIN RESULTS: A total of 89 patients were analyzed (mean age, 69 ± 15 yr; 23% female; 12% of hospital admission survival): capnograms exhibited various degrees of oscillations, quantified by the opening index. CO2 value varied considerably across oscillations related to consecutive chest compressions. In bench and cadavers, similar capnograms were reproduced with different degrees of airway closure. Differences in airway patency were associated with huge changes in delivered ventilation. The opening index and delivered ventilation increased with positive end-expiratory pressure, without affecting intrathoracic pressure. Maximal EtCO2 recorded between ventilator breaths reflected alveolar CO2 (bench). CONCLUSIONS: During chest compressions, intrathoracic airway patency greatly affects the delivered ventilation. The expired CO2 signal can reflect CPR effectiveness but is also dependent on airway patency. The maximal EtCO2 recorded between consecutive ventilator breaths best reflects alveolar CO2.

Worldwide management of donors after neurological death: a systematic review and narrative synthesis of guidelines.

OBJECTIVE: The objectives of this study were to systematically identify and describe guidelines for the care of neurologically deceased donors and to evaluate their methodological quality, with the aim of informing and supporting the new Canadian guidelines for the management of organ donors. METHODOLOGY: Following a systematic search, we included any document endorsed by an organ donation organization, a professional society, or a government, that aims to direct the medical management of adult, neurologically deceased, multi-organ donors. We extracted recommendations pertaining to six domains: the autonomic storm, hemodynamic instability, hormone supplementation, ventilation, blood product transfusions, and general intensive care unit (ICU) care. Methodological quality of the guidelines was assessed by the validated AGREE-II tool. MAIN FINDINGS: This review includes 27 clinical practice guidelines representing 26 countries published between 1993 and 2019. Using the AGREE-II validated tool for the evaluation of guidelines' quality, documents generally scored well on their scope and clarity of presentation. Nevertheless, quality was limited in terms of the scientific rigor of guideline development. Recommendations varied substantially across the domains of managing the autonomic storm, subsequent management of hemodynamic instability, hormone therapy, mechanical ventilation, blood product transfusion, and general ICU care. We found consistent recommendations for low tidal volume ventilation subsequent to the publication of a landmark clinical trial. CONCLUSION: Highly inconsistent recommendations for deceased donor care summarized in this review likely reflect the relatively slow emergence of high-quality clinical research in this field, as well as a late uptake of recent validated guideline methodology. Even in this context of few randomized-controlled trials, our group supported the need for new Canadian guidelines for the management of organ donors that follow rigorous recognized methodology and grading of the evidence. TRIAL REGISTRATION: PROSPERO (CRD42018084012); registered 25 February 2016.

RéSUMé: OBJECTIF: Les objectifs de cette étude étaient d'identifier et de décrire de façon systématique les lignes directrices concernant les soins à prodiguer aux donneurs suivant un décès neurologique et d'évaluer leur qualité méthodologique, avec pour but d'informer et d'appuyer les nouvelles lignes directrices canadiennes de prise en charge des donneurs d'organes. MéTHODOLOGIE: À la suite d'une recherche systématique, nous avons inclus tout document endossé par un organisme de dons d'organes, une société professionnelle ou un gouvernement et ayant pour but d'orienter la prise en charge médicale des donneurs adultes d'organes multiples à la suite d'un décès neurologique. Nous avons extrait les recommandations touchant six domaines : la tempête catécholaminergique, l'instabilité hémodynamique, la supplémentation hormonale, la ventilation, les transfusions de produits sanguins et les soins généraux à l'unité de soins intensifs (USI). La qualité méthodologique des lignes directrices a été évaluée avec l'outil validé AGREE-II. CONSTATIONS PRINCIPALES: Cette revue porte sur 27 guides d'exercice cliniques représentant 26 pays et publiés entre 1993 et 2019. En se fondant sur l'outil validé AGREE-II pour l'évaluation de la qualité des lignes directrices, les documents ont en règle générale obtenu un bon score en ce qui touchait à leurs objectifs et à la clarté de leur présentation. Toutefois, la qualité était limitée en matière de rigueur scientifique employée pour la mise au point des lignes directrices. Les recommandations variaient considérablement concernant les questions pertinentes à la prise en charge de la tempête catécholaminergique, à la prise en charge subséquente de l'instabilité hémodynamique, à l'hormonothérapie, à la ventilation mécanique, à la transfusion de produits sanguins, et aux soins généraux à l'USI. À la suite de la publication d'une étude clinique importante, les recommandations concernant la ventilation à volume courant bas étaient constantes. CONCLUSION: Le manque de cohérence des lignes directrices touchant les soins aux donneurs décédés résumées dans cette revue est probablement le reflet de l'émergence relativement lente de recherches cliniques de qualité élevée dans ce domaine, ainsi que de l'adoption tardive des méthodologies récentes et validées pour l'élaboration de lignes directrices. Même dans le contexte actuel de rareté d'études randomisées contrôlées, notre groupe appuie la nécessité de nouvelles lignes directrices canadiennes concernant la prise en charge des donneurs d'organes qui respectent une méthodologie reconnue et rigoureuse ainsi qu'une classification des données probantes. ENREGISTREMENT DE L'éTUDE: PROSPERO (CRD42018084012); enregistrée le 25 février 2016.

New physiological insights in ventilation during cardiopulmonary resuscitation.

PURPOSE OF REVIEW: In the setting of cardiopulmonary resuscitation (CPR), classical physiological concept about ventilation become challenging. Ventilation may exert detrimental hemodynamic effects that must be balanced with its expected benefits. The risks of hyperventilation have been thoroughly addressed, even questioning the need for ventilation, emphasizing the need to prioritize chest compression quality. However, ventilation is mandatory for adequate gas exchange as soon as CPR is prolonged. Factors affecting the capability of chest compressions to produce alveolar ventilation are poorly understood. In this review, we discuss the conventional interpretation of interactions between ventilation and circulation, from the perspective of novel physiological observations. RECENT FINDINGS: Many patients with cardiac arrest exhibit 'intrathoracic airway closure.' This phenomenon is associated with lung volume reduction, impedes chest compressions to generate ventilation and overall limits the delivered ventilation. This phenomenon can be reversed by the application of small levels of positive end-expiratory pressure. Also, a novel interpretation of the capnogram can rate the magnitude of this phenomenon, contributing to clarify the physiological meaning of exhaled CO2 and may help assess the real amount of delivered ventilation. SUMMARY: Recent advances in the understanding of ventilatory physiology during CPR shows that capnogram analysis not only provides information on the quality of resuscitation but also on the amount of ventilation produced by chest compressions and on the total amount of ventilation.

Esophageal Manometry and Regional Transpulmonary Pressure in Lung Injury.

RATIONALE: Esophageal manometry is the clinically available method to estimate pleural pressure, thus enabling calculation of transpulmonary pressure (Pl). However, many concerns make it uncertain in which lung region esophageal manometry reflects local Pl. OBJECTIVES: To determine the accuracy of esophageal pressure (Pes) and in which regions esophageal manometry reflects pleural pressure (Ppl) and Pl; to assess whether lung stress in nondependent regions can be estimated at end-inspiration from Pl. METHODS: In lung-injured pigs (n = 6) and human cadavers (n = 3), Pes was measured across a range of positive end-expiratory pressure, together with directly measured Ppl in nondependent and dependent pleural regions. All measurements were obtained with minimal nonstressed volumes in the pleural sensors and esophageal balloons. Expiratory and inspiratory Pl was calculated by subtracting local Ppl or Pes from airway pressure; inspiratory Pl was also estimated by subtracting Ppl (calculated from chest wall and respiratory system elastance) from the airway plateau pressure. MEASUREMENTS AND MAIN RESULTS: In pigs and human cadavers, expiratory and inspiratory Pl using Pes closely reflected values in dependent to middle lung (adjacent to the esophagus). Inspiratory Pl estimated from elastance ratio reflected the directly measured nondependent values. CONCLUSIONS: These data support the use of esophageal manometry in acute respiratory distress syndrome. Assuming correct calibration, expiratory Pl derived from Pes reflects Pl in dependent to middle lung, where atelectasis usually predominates; inspiratory Pl estimated from elastance ratio may indicate the highest level of lung stress in nondependent "baby" lung, where it is vulnerable to ventilator-induced lung injury.

A systematic review of interventions to facilitate extubation in patients difficult-to-wean due to delirium, agitation, or anxiety and a meta-analysis of the effect of dexmedetomidine.

BACKGROUND: Delirium, agitation, and anxiety may hinder weaning from mechanical ventilation and lead to increased morbidity and healthcare costs. The most appropriate clinical approach to weaning in these contexts remains unclear and challenging to clinicians. The objective of this systematic review was to identify effective and safe interventions to wean patients that are difficult-to-wean from mechanical ventilation due to delirium, agitation, or anxiety. METHODS: A systematic review was performed using MEDLINE, EMBASE, and PubMed. Studies evaluating mechanically ventilated patients deemed difficult-to-wean due to delirium, agitation, or anxiety, and comparing the effects of an intervention with a comparator arm were sought. Time-to-extubation was the primary outcome while the secondary outcome was intensive care unit (ICU) length of stay. RESULTS: From 10,860 studies identified, eight met the inclusion criteria: six studies assessed dexmedetomidine while the remaining two assessed loxapine and biofeedback. Pooled analysis of studies assessing dexmedetomidine showed reduced time-to-extubation (six studies, n = 303) by 10.9 hr compared with controls (95% confidence interval [CI], -15.7 to -6.1; I2 = 68%) and ICU length of stay (four studies, n = 191) by 2.6 days (95% CI, 1.9 to 3.3; I2 = 0%). Nevertheless, the evidence was deemed to be of low quality given the small sample sizes and high heterogeneity. Studies assessing other interventions did not identify improvements compared with controls. Safety assessment was globally poorly reported. CONCLUSIONS: This systematic review and meta-analysis provides low quality evidence to suggest the use of dexmedetomidine in patients deemed difficult-to-wean due to agitation, delirium, or anxiety. Insufficient evidence was found regarding other interventions to provide any recommendation. TRIAL REGISTRATION: PROSPERO (CRD42016042528); registered 15 July, 2016.

RéSUMé: CONTEXTE: Le délirium, l'agitation et l'anxiété peuvent compliquer le sevrage de la ventilation mécanique et aboutir à une augmentation de la morbidité et du coût des soins de santé. L'approche clinique la plus adaptée au sevrage dans ces circonstances n'est pas claire et reste un défi pour les cliniciens. L'objectif de cette étude systématique était d'identifier des interventions efficaces et sécuritaires pour sevrer les patients « difficiles à sevrer ¼ de la ventilation mécanique en raison d'un délirium, d'une agitation ou d'anxiété. MéTHODES: Une revue systématique a été menée en utilisant les bases de données MEDLINE, EMBASE et PubMed. Les études évaluant des patients sous ventilation mécanique jugés difficiles à sevrer en raison d'un délirium, d'une agitation ou d'anxiété, comparant les effets d'une intervention à celle d'un bras comparateur ont été recherchées. Le critère d'évaluation principal a été le délai jusqu'à l'extubation et le critère d'évaluation secondaire a été la durée de séjour en unité de soins intensifs (USI). RéSULTATS: À partir de 10 860 études identifiées, huit satisfaisaient les critères d'inclusion : six études ont évalué la dexmédétomidine tandis que les deux dernières ont évalué la loxapine et le biofeedback. L'analyse groupée des études évaluant la dexmédétomidine a montré une réduction du délai d'extubation (six études, n = 303) de 10,9 heures comparativement aux contrôles (intervalle de confiance [IC] à 95 % : -15,7 à -6,1; I2 = 68 %) et de la durée du séjour en USI (quatre études, n = 191) de 2,6 jours (IC à 95 % : 1,9 à 3,3; I2 = 0 %). Néanmoins, les résultats sont de faible qualité compte tenu de la petite taille des échantillons et d'une grande hétérogénéité. Les études évaluant d'autres interventions n'ont pas identifié d'améliorations par rapport aux contrôles. D'une manière générale, les évaluations de l'innocuité ont été médiocrement décrites. CONCLUSIONS: Cette étude systématique et la méta-analyse procurent une preuve de qualité basse pour suggérer l'utilisation de la dexmédétomidine chez des patients considérés difficiles à sevrer en raison d'un délirium, d'une agitation ou d'anxiété. Les données probantes concernant les autres interventions ont été jugées insuffisantes pour permettre des recommandations quelconques. ENREGISTREMENT DE L'ESSAI CLINIQUE: PROSPERO (CRD42016042528); enregistré le 15 juillet 2016.

A Canadian survey of critical care physicians' hemodynamic management of deceased organ donors.

PURPOSE: We sought to characterize Canadian physicians' perspectives and stated practices regarding their hemodynamic care of deceased organ donors. METHODS: We designed a 24-item electronic survey that was independently pretested for relevance, clarity, and intra-rater reliability by ten critical care clinicians. With the help of provincial organ donation organizations (ODO), we identified intensive care units (ICUs) with a high volume of adult deceased donors (defined by the management of five or more donors per year for two consecutive years). Medical directors of these high-volume ICUs helped identify ICU physicians to whom our survey was emailed. RESULTS: Of the 448 ICU physicians from 37 centres in nine provinces that were emailed, 184/448 (41.1%) responded to one or more survey questions. Respondents identified specialist nurses from ODOs as their primary source of guidance in donor care (107/165; 60%). They typically diagnosed an autonomic storm according to a rise in blood pressure (159/165; 96.4%) and/or heart rate (135/165; 81.8%); nevertheless, their stated management varied substantially. After termination of the autonomic storm, preferred first-line vasopressors were norepinephrine (93/164; 56.7%) and vasopressin (68/164; 41.5%). Twenty-one respondents (21/162; 13.0%) reported that they never administer inotropes to donors. Corticosteroid and thyroid hormone prescriptions for all donors was reported by 62/161 (37.6%) and 50/161 (31.1%) respondents, respectively. Respondents perceived an influence from ODO nurses or transplant physicians when prescribing corticosteroids (77/161; 47.8%) and/or thyroid hormones (33/161; 20.5%) CONCLUSION: We observed important variability in self-perceived practices of ICU physicians in the hemodynamic management of deceased donors, particularly in the treatment of the autonomic storm, in the prescription of hormone therapy, and in the administration of inotropes.

RéSUMé: OBJECTIF: Nous avons tenté de caractériser les perspectives et les pratiques déclarées des médecins canadiens concernant les soins hémodynamiques prodigués aux donneurs d'organes décédés. MéTHODE: Nous avons mis au point un sondage électronique comportant 24 éléments et l'avons préalablement testé pour déterminer sa pertinence, sa clarté et sa fidélité interobservateur par dix médecins de soins intensifs. Avec l'aide des organismes de dons d'organes (ODO) provinciaux, nous avons identifié les unités de soins intensifs (USI) prenant en charge un volume élevé de donneurs adultes décédés (prise en charge de cinq donneurs ou plus par an pendant deux années consécutives). Les directeurs médicaux de ces USI à haut volume nous ont aidé à identifier les médecins de l'USI à qui envoyer le sondage par courriel. RéSULTATS: Parmi les 448 médecins de l'USI issus de 37 centres dans neuf provinces ayant reçu le sondage, 184/448 (41,1 %) ont répondu à une question ou plus de notre questionnaire. Les répondants ont identifié les infirmières spécialisées des ODO en tant que source principale de conseils quant aux soins à prodiguer aux donneurs (107/165; 60 %). Un diagnostic de tempête adrénergique était fréquemment posé suite à une augmentation de la tension artérielle (159/165; 96,4 %) et/ou de la fréquence cardiaque (135/165; 81,8 %); toutefois, la prise en charge déclarée variait considérablement. Après la fin de la tempête adrénergique, les vasopresseurs de première intention les plus utilisés étaient la norépinéphrine (93/164; 56,7 %) et la vasopressine (68/164; 41,5 %). Vingt-et-un répondants (21/162; 13,0 %) ont rapporté ne jamais administrer d'inotropes aux donneurs. Les prescriptions systématiques de corticostéroïdes et d'hormones thyroïdiennes à tous les donneurs ont été rapportées par 62/161 (37,6 %) et 50/161 (31,1 %) répondants, respectivement. Les répondants se sentaient influencés par les infirmières des ODO et les médecins spécialisés en greffe lors de la prescription des corticostéroïdes (77/161; 47,8 %) et/ou des hormones thyroïdiennes (33/161; 20,5 %). CONCLUSION: Nous avons observé une variabilité considérable dans les pratiques perçues des médecins de l'USI quant à la prise en charge hémodynamique des donneurs décédés, particulièrement en ce qui a trait au traitement de la tempête adrénergique, à la prescription de thérapie hormonale et à l'administration d'inotropes.

A systematic review of vasopressor blood pressure targets in critically ill adults with hypotension.

PURPOSE: Clinicians must balance the risks from hypotension with the potential adverse effects of vasopressors. Experts have recommended a mean arterial pressure (MAP) target of at least 65 mmHg, and higher in older patients and in patients with chronic hypertension or atherosclerosis. We conducted a systematic review of randomized-controlled trials comparing higher vs lower blood pressure targets for vasopressor therapy administered to hypotensive critically ill patients. METHODS: We searched MEDLINE®, EMBASE™, and the Cochrane Central Register of Controlled Trials for studies of higher vs lower blood pressure targets for vasopressor therapy in critically ill hypotensive adult patients. Two reviewers independently assessed trial eligibility based on titles and abstracts, and they then selected full-text reports. Outcomes, subgroups, and analyses were prespecified. We used GRADE (Grading of Recommendations Assessment, Development and Evaluation) to rate the overall confidence in the estimates of intervention effects. RESULTS: Of 8001 citations, we retrieved 57 full-text articles and ultimately included two randomized-controlled trials (894 patients). Higher blood pressure targets were not associated with lower mortality (relative risk [RR], 1.05; 95% confidence interval [CI], 0.90 to 1.23; P = 0.54), and neither age (P = 0.17) nor chronic hypertension (P = 0.32) modified the overall effect. Nevertheless, higher blood pressure targets were associated with a greater risk of new-onset supraventricular cardiac arrhythmia (RR, 2.08; 95% CI, 1.28 to 3.38; P < 0.01). CONCLUSION: Current evidence does not support a MAP target > 70 mmHg in hypotensive critically ill adult patients requiring vasopressor therapy.