Predictors of acute kidney injury after lung resection surgery: a retrospective case-control study.

PURPOSE: Patients undergoing lung resection are at increased risk for acute kidney injury (AKI) in the immediate postoperative period, with important consequences for longer term morbidity and mortality. Lung resection surgery has unique considerations that could increase the risk of AKI, including lung resection volume, duration of one-lung ventilation (OLV), and intraoperative fluid restriction. Yet, specific risk factor data are lacking. The objective of this study was to identify independent risk factors for early AKI after lung resection surgery. METHODS: We conducted a retrospective case-control study of all patients presenting for elective lung resection surgery at an academic medical centre over a four-year period. Cases were patients who experienced an AKI and control patients were those who did not experience an AKI, based on KDIGO criteria. Baseline demographics and comorbidities along with duration of OLV and amount of lung resected were collected by retrospective chart review. The data were analyzed using multivariable logistic regression to identify independent predictors of AKI. RESULTS: Acute kidney injury occurred within 48 hr in 57/1,045 (5.5%; 95% confidence interval, 4.2 to 7.0) of patients. On multivariable analysis, our model of best fit included preoperative serum creatinine, male sex, use of angiotensin II receptor blockers, and duration of OLV. The rate of complications, intensive care unit admission, and risk of death were all higher in the group of patients who experienced AKI. CONCLUSIONS: Acute kidney injury occurs frequently after lung resection surgery and is associated with increased risk of postoperative complications. Increased duration of OLV may be a risk factor for AKI in this population.

RéSUMé: OBJECTIF: Les patient·es bénéficiant d'une résection pulmonaire courent un risque accru d'insuffisance rénale aiguë (IRA) en période postopératoire immédiate, avec des conséquences importantes pour la morbidité et la mortalité à long terme. La chirurgie de résection pulmonaire entraîne des considérations uniques qui pourraient augmenter le risque d'IRA, notamment le volume de la résection pulmonaire, la durée de la ventilation unipulmonaire (VUP) et la restriction liquidienne peropératoire. Pourtant, les données spécifiques sur les facteurs de risque font défaut. L'objectif de cette étude était d'identifier les facteurs de risque indépendants d'IRA précoce après une chirurgie de résection pulmonaire. MéTHODE: Nous avons mené une étude cas témoins rétrospective de toute la patientèle se présentant pour une chirurgie de résection pulmonaire non urgente dans un centre médical universitaire sur une période de quatre ans. Les cas étaient des patient·es qui ont présenté une IRA et des patient·es témoins qui n'ont pas eu d'IRA, selon les critères KDIGO. Les données démographiques et les comorbidités de base ainsi que la durée de la VUP et le volume de poumon réséqué ont été recueillis par examen rétrospectif des dossiers. Les données ont été analysées à l'aide d'une régression logistique multivariée afin d'identifier des prédicteurs indépendants d'IRA. RéSULTATS: Une insuffisance rénale aiguë est survenue dans les premières 48 heures postopératoires chez 57/1045 (5,5 %; intervalle de confiance à 95 %, 4,2 à 7,0) des patient·es. Sur l'analyse multivariée, notre modèle de meilleur ajustement incluait la créatininémie préopératoire, le sexe masculin, l'utilisation d'antagonistes des récepteurs de l'angiotensine II et la durée de la VUP. Le taux de complications, l'admission en unité de soins intensifs et le risque de décès étaient tous plus élevés dans le groupe de patient·es ayant présenté une IRA. CONCLUSION: L'insuffisance rénale aiguë survient fréquemment après une chirurgie de résection pulmonaire et est associée à un risque accru de complications postopératoires. Une durée prolongée de VUP pourrait constituer un facteur de risque d'IRA dans cette population.

Emergency airway management in a tertiary trauma centre (AIRMAN): a one-year prospective longitudinal study.

PURPOSE: Emergency airway management can be associated with a range of complications including long-term neurologic injury and death. We studied the first-pass success rate with emergency airway management in a tertiary care trauma centre. Secondary outcomes were to identify factors associated with first-pass success and factors associated with adverse events peri-intubation. METHODS: We performed a single-centre, prospective, observational study of patients ≥ 17 yr old who were intubated in the emergency department (ED), surgical intensive care unit (SICU), medical intensive care unit (MICU), and inpatient wards at our institution. Ethics approval was obtained from the local research ethics board. RESULTS: In a seven-month period, there were 416 emergency intubations and a first-pass success rate of 73.1%. The first-pass success rates were 57.5% on the ward, 66.1% in the intensive care units (ICUs) and 84.3% in the ED. Equipment also varied by location; videolaryngoscopy use was 65.1% in the ED and only 10.6% on wards. A multivariate regression model using the least absolute shrinkage and selection algorithm (LASSO) showed that the odds ratios for factors associated with two or more intubation attempts were location (wards, 1.23; MICU, 1.24; SICU, 1.19; reference group, ED), physiologic instability (1.19), an anatomically difficult airway (1.05), hypoxemia (1.98), lack of neuromuscular blocker use (2.28), and intubator inexperience (1.41). CONCLUSIONS: First-pass success rates varied widely between locations within the hospital and were less than those published from similar institutions, except for the ED. We are revamping ICU protocols to improve the first-pass success rate.

RéSUMé: OBJECTIF: La prise en charge d'urgence des voies aériennes peut être associée à une multitude de complications, y compris des lésions neurologiques à long terme et la mort. Nous avons étudié le taux de réussite à la première tentative lors de la prise en charge d'urgence des voies aériennes dans un centre de traumatologie tertiaire. Les critères d'évaluation secondaires étaient l'identification des facteurs associés à la réussite de la première tentative et des facteurs associés aux événements indésirables péri-intubation. MéTHODE: Nous avons réalisé une étude observationnelle prospective monocentrique sur des patients âgés de 17 ans ou plus qui avaient été intubés à l'urgence, à l'unité de soins intensifs chirurgicaux (USIC), à l'unité de soins intensifs médicaux (USIM) et aux étages dans notre établissement. L'approbation a été obtenue du comité d'éthique de la recherche local. RéSULTATS: Au cours d'une période de sept mois, il y a eu 416 intubations d'urgence et un taux de réussite à la première tentative de 73,1 %. Les taux de réussite à la première tentative étaient de 57,5 % aux étages, de 66,1 % dans les unités de soins intensifs (USI) et de 84,3 % à l'urgence. Le matériel variait également selon l'emplacement; l'utilisation de la vidéolaryngoscopie était de 65,1 % à l'urgence et de seulement 10,6 % aux étages. Un modèle de régression multivariée utilisant l'algorithme LASSO (Least Absolute Shrinkage and Selection Algorithm) a montré que les rapports de cotes pour les facteurs associés à deux tentatives d'intubation ou plus étaient l'emplacement (étages, 1,23; USIM, 1,24; USIC, 1,19; groupe de référence, urgence), l'instabilité physiologique (1,19), des voies aériennes présentant des complications anatomiques (1,05), l'hypoxémie (1,98), la non-utilisation de bloqueurs neuromusculaires (2,28) et l'inexpérience de la personne pratiquant l'intubation (1,41). CONCLUSION: Les taux de réussite à la première tentative variaient considérablement d'un emplacement à l'autre au sein de l'hôpital et étaient inférieurs à ceux publiés par des établissements comparables, à l'exception du service des urgences. Nous retravaillons les protocoles des soins intensifs afin d'améliorer le taux de réussite à la première tentative.

Persistence of live virus in critically ill patients infected with SARS-COV-2: a prospective observational study.

BACKGROUND: Research on the duration of infectivity of ICU patients with COVID-19 has been sparse. Tests based on Reverse Transcriptase polymerase chain reaction (RT-PCR) detect both live virus and non-infectious viral RNA. We aimed to determine the duration of infectiousness based on viral culture of nasopharyngeal samples of patients with COVID-19. METHODS: Prospective observational study in adult intensive care units with a diagnosis of COVID-19 Pneumonia. Patients had repeated nasopharyngeal sampling performed after day 10 of ICU admission. Culture positive rate (based on viral culture on Vero cells in a level 4 lab) and Cycle threshold from RT-PCR were measured. RESULTS: Nine patients of the 108 samples (8.3%, 95% CI 3.9-15.2%) grew live virus at a median of 13 days (interquartile range 11-19) after their initial positive test. 74.1% of patients were RT-PCR positive but culture negative, and the remaining (17.6%) were RT-PCR and culture negative. Cycle threshold showed excellent ability to predict the presence of live virus, with a Ct < 25 with an AUC of 0.90 (95% CI 0.83-0.97, p < 0.001). The specificity of a Ct > 25 to predict negative viral culture was 100% (95% CI 70-100%). CONCLUSION: 8.3% of our ICU patients with COVID-19 grew live virus at a median of 13 days post-initial positive RT-PCR test. Severity of illness, use of mechanical ventilation, and time between tests did not predict the presence of live virus. Cycle threshold of > 25 had the best ability to determine the lack of live virus in these patents.

Infectivity of severe acute respiratory syndrome coronavirus 2 in children compared with adults.

BACKGROUND: The role of children in the transmission and community spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unclear. We aimed to quantify the infectivity of SARS-CoV-2 in nasopharyngeal samples from children compared with adults. METHODS: We obtained nasopharyngeal swabs from adult and pediatric cases of coronavirus disease 2019 (COVID-19) and from their contacts who tested positive for SARS-CoV-2 in Manitoba between March and December 2020. We compared viral growth in cell culture, cycle threshold values from the reverse transcription polymerase chain reaction (RT-PCR) of the SARS-CoV-2 envelope (E) gene and the 50% tissue culture infective dose (TCID50/mL) between adults and children. RESULTS: Among 305 samples positive for SARS-CoV-2 by RT-PCR, 97 samples were from children aged 10 years or younger, 78 were from children aged 11-17 years and 130 were from adults (≥ 18 yr). Viral growth in culture was present in 31% of samples, including 18 (19%) samples from children 10 years or younger, 18 (23%) from children aged 11-17 years and 57 (44%) from adults (children v. adults, odds ratio 0.45, 95% confidence interval [CI] 0.28-0.72). The cycle threshold was 25.1 (95% CI 17.7-31.3) in children 10 years or younger, 22.2 (95% CI 18.3-29.0) in children aged 11-17 years and 18.7 (95% CI 17.9-30.4) in adults (p < 0.001). The median TCID50/mL was significantly lower in children aged 11-17 years (316, interquartile range [IQR] 178-2125) than adults (5620, IQR 1171 to 17 800, p < 0.001). Cycle threshold was an accurate predictor of positive culture in both children and adults (area under the receiver-operator curve, 0.87, 95% CI 0.81-0.93 v. 0.89, 95% CI 0.83-0.96, p = 0.6). INTERPRETATION: Compared with adults, children with nasopharyngeal swabs that tested positive for SARS-CoV-2 were less likely to grow virus in culture, and had higher cycle thresholds and lower viral concentrations, suggesting that children are not the main drivers of SARS-CoV-2 transmission.

Canadian recommendations for training and performance in basic perioperative point-of-care ultrasound: recommendations from a consensus of Canadian anesthesiology academic centres.

Point-of-care ultrasound (POCUS) uses ultrasound at the bedside to aid decision-making in acute clinical scenarios. The increased use of ultrasound for regional anesthesia and vascular cannulation, together with more anesthesiologists trained in transesophageal echocardiography have contributed to the widespread use of POCUS in perioperative care. Despite the support of international experts, the practice of POCUS in perioperative care is variable as Canadian guidelines for anesthesiologists do not currently exist. Using a Delphi process of online surveys and a face-to-face national Canadian meeting, we developed a consensus statement for basic POCUS (bPOCUS) performance and training with a group of national experts from all Canadian universities. The group of experts consisted of 55 anesthesiologists from 12 Canadian universities considered local leaders in the field. An initial exploratory online survey of 47 statements was conducted. These statements were derived from previous generic guidelines or consensus conferences, or were based on current literature. Fourteen statements reached full consensus, 19 had 90-100% agreement, and 14 had less than 90% agreement. Eight new statements were proposed during the national meeting, and all statements without full agreement were discussed. A second online survey included 42 modified or new statements. From this second survey, 16 statements obtained full consensus, 39 had very good agreement, and one had good agreement. The final document includes 56 statements that define the scope of practice and necessary training for perioperative bPOCUS. The statements include five bPOCUS domains: cardiac, lung, airway, gastric, and abdomen. The use of bPOCUS is evolving and will play a significant role in perioperative medicine. This consensus statement aims to define a Canadian national standard on which curricula may be based. It also provides a framework to allow further development of bPOCUS in the perioperative setting.

RéSUMé: L'échographie ciblée (POCUS) utilise l'échographie au chevet des patients pour faciliter la prise de décisions dans les situations cliniques urgentes. L'utilisation accrue de l'échographie pour l'anesthésie régionale et la cannulation vasculaire, ainsi que l'augmentation du nombre d'anesthésologistes formés à l'échocardiographie transesophagienne, ont contribué à l'utilisation généralisée de l'échographie ciblée dans les soins périopératoires. Malgré son endossement par des experts internationaux, la pratique de l'échographie ciblée en soins périopératoires est variable, car il n'existe pas, à l'heure actuelle, de lignes directrices canadiennes destinées aux anesthésiologistes. À l'aide d'un processus Delphi de sondages en ligne et d'une réunion nationale canadienne en personne, un groupe d'experts nationaux provenant de toutes les universités canadiennes a élaboré une déclaration consensuelle pour la formation de base en et l'exécution de l'échographie ciblée (bPOCUS). Le groupe d'experts était composé de 55 anesthésiologistes issus de 12 universités canadiennes considérés comme des chefs de file locaux dans le domaine. Un premier sondage exploratoire en ligne comportant 47 énoncés a été réalisé. Ces énoncés étaient dérivés de lignes directrices antérieures ou de conférences consensuelles, ou étaient fondés sur la littérature actuelle. Quatorze énoncés ont obtenu un consensus complet, 19 ont atteint un taux de 90 à 100 %, et 14 ont obtenu moins de 90 % d'accord. Huit nouveaux énoncés ont été proposés au cours de la réunion nationale, et tous les énoncés n'ayant pas obtenu d'accord complet ont été discutés. Un deuxième sondage en ligne comprenait 42 énoncés modifiés ou nouveaux. Dans ce deuxième sondage, 16 énoncés ont obtenu un consensus total, 39 un très bon accord et un énoncé un bon accord. Le document final comporte 56 énoncés qui définissent le champ de pratique et la formation nécessaire pour l'échographie ciblée périopératoire de base. Les énoncés portent sur cinq domaines de l'échographie ciblée de base : échographie cardiaque, pulmonaire, des voies respiratoires, gastrique et abdominale. L'utilisation de l'échographie ciblée de base évolue et jouera un rôle important en médecine périopératoire. Cette déclaration consensuelle vise à définir une norme nationale canadienne sur laquelle les programmes d'études pourront s'appuyer. Elle fournit également un cadre pour encourager le développement ultérieur de l'échographie ciblée de base dans un contexte périopératoire.

Predicting Infectious Severe Acute Respiratory Syndrome Coronavirus 2 From Diagnostic Samples.

BACKGROUND: Reverse-transcription polymerase chain reaction (RT-PCR) has become the primary method to diagnose viral diseases, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). RT-PCR detects RNA, not infectious virus; thus, its ability to determine duration of infectivity of patients is limited. Infectivity is a critical determinant in informing public health guidelines/interventions. Our goal was to determine the relationship between E gene SARS-CoV-2 RT-PCR cycle threshold (Ct) values from respiratory samples, symptom onset to test (STT), and infectivity in cell culture. METHODS: In this retrospective cross-sectional study, we took SARS-CoV-2 RT-PCR-confirmed positive samples and determined their ability to infect Vero cell lines. RESULTS: Ninety RT-PCR SARS-CoV-2-positive samples were incubated on Vero cells. Twenty-six samples (28.9%) demonstrated viral growth. Median tissue culture infectious dose/mL was 1780 (interquartile range, 282-8511). There was no growth in samples with a Ct > 24 or STT > 8 days. Multivariate logistic regression using positive viral culture as a binary predictor variable, STT, and Ct demonstrated an odds ratio (OR) for positive viral culture of 0.64 (95% confidence interval [CI], .49-.84; P < .001) for every 1-unit increase in Ct. Area under the receiver operating characteristic curve for Ct vs positive culture was OR, 0.91 (95% CI, .85-.97; P < .001), with 97% specificity obtained at a Ct of > 24. CONCLUSIONS: SARS-CoV-2 Vero cell infectivity was only observed for RT-PCR Ct < 24 and STT < 8 days. Infectivity of patients with Ct > 24 and duration of symptoms > 8 days may be low. This information can inform public health policy and guide clinical, infection control, and occupational health decisions. Further studies of larger size are needed.

Incorporating Dynamic Assessment of Fluid Responsiveness Into Goal-Directed Therapy: A Systematic Review and Meta-Analysis.

OBJECTIVE: Dynamic tests of fluid responsiveness have been developed and investigated in clinical trials of goal-directed therapy. The impact of this approach on clinically relevant outcomes is unknown. We performed a systematic review and meta-analysis to evaluate whether fluid therapy guided by dynamic assessment of fluid responsiveness compared with standard care improves clinically relevant outcomes in adults admitted to the ICU. DATA SOURCES: Randomized controlled trials from MEDLINE, EMBASE, CENTRAL, clinicaltrials.gov, and the International Clinical Trials Registry Platform from inception to December 2016, conference proceedings, and reference lists of relevant articles. STUDY SELECTION: Two reviewers independently identified randomized controlled trials comparing dynamic assessment of fluid responsiveness with standard care for acute volume resuscitation in adults admitted to the ICU. DATA EXTRACTION: Two reviewers independently abstracted trial-level data including population characteristics, interventions, clinical outcomes, and source of funding. Our primary outcome was mortality at longest duration of follow-up. Our secondary outcomes were ICU and hospital length of stay, duration of mechanical ventilation, and frequency of renal complications. The internal validity of trials was assessed in duplicate using the Cochrane Collaboration's Risk of Bias tool. DATA SYNTHESIS: We included 13 trials enrolling 1,652 patients. Methods used to assess fluid responsiveness included stroke volume variation (nine trials), pulse pressure variation (one trial), and stroke volume change with passive leg raise/fluid challenge (three trials). In 12 trials reporting mortality, the risk ratio for death associated with dynamic assessment of fluid responsiveness was 0.59 (95% CI, 0.42-0.83; I = 0%; n = 1,586). The absolute risk reduction in mortality associated with dynamic assessment of fluid responsiveness was -2.9% (95% CI, -5.6% to -0.2%). Dynamic assessment of fluid responsiveness was associated with reduced duration of ICU length of stay (weighted mean difference, -1.16 d [95% CI, -1.97 to -0.36]; I = 74%; n = 394, six trials) and mechanical ventilation (weighted mean difference, -2.98 hr [95% CI, -5.08 to -0.89]; I = 34%; n = 334, five trials). Three trials were adjudicated at unclear risk of bias; the remaining trials were at high risk of bias. CONCLUSIONS: In adult patients admitted to intensive care who required acute volume resuscitation, goal-directed therapy guided by assessment of fluid responsiveness appears to be associated with reduced mortality, ICU length of stay, and duration of mechanical ventilation. High-quality clinical trials in both medical and surgical ICU populations are warranted to inform routine care.

Perioperative implications of thoracic decortications: a retrospective cohort study.

PURPOSE: An increasing number of thoracic decortications have been performed in Manitoba, from five in 2007 to 45 in 2014. The primary objective of this study was to define the epidemiology of decortications in Manitoba. The secondary objective was to compare patients who underwent decortication due to primary infectious vs non-infectious etiology with respect to their perioperative outcomes. METHODS: Data for this cohort study were extracted from consecutive charts of all adult patients who underwent a decortication in Manitoba from 2007-2014 inclusive. RESULTS: One hundred ninety-two patients underwent a decortication. The most frequent disease processes resulting in a decortication were pneumonia (60%), trauma (13%), malignancy (8%), and procedural complications (5%). The number of decortications due to complications of pneumonia rose at the greatest rate, from three cases in 2007 to 29 cases in 2014. Performing a decortication for an infectious vs a non-infectious etiology was associated with a higher rate of the composite postoperative outcome of myocardial infarction, acute kidney injury, need of vasopressors for > 12 hr, and mechanical ventilation for > 48 hr (44.4% vs 24.2%, respectively; relative risk, 1.83; 95% confidence interval, 1.1 to 2.9; P = 0.01). CONCLUSION: There has been a ninefold increase in decortications over an eight-year period. Potential causes include an increase in the incidence of pneumonia, increased organism virulence, host changes, and changes in practice patterns. Patients undergoing decortication for infectious causes had an increased risk for adverse perioperative outcomes. Anesthesiologists need to be aware of the high perioperative morbidity of these patients and the potential need for postoperative admission to an intensive care unit.

Comparaison de l'infectivité du coronavirus du syndrome respiratoire aigu sévère 2 chez les enfants et les adultes.

CONTEXTE: Le rôle des enfants dans la propagation et la transmission communautaire du coronavirus du syndrome respiratoire aigu sévère 2 (SRAS-CoV-2) est encore mal compris. Nous visons à quantifier l'infectivité du SRAS-CoV-2 d'échantillons nasopharyngés provenant d'enfants comparativement à ceux provenant d'adultes. MÉTHODES: Nous avons obtenu des écouvillons nasopharyngés de cas adultes et pédiatriques de la maladie à coronavirus 2019 (COVID-19) ainsi que de leurs contacts qui ont obtenu un résultat positif à la présence du SRAS-CoV-2 lors d'un test de dépistage au Manitoba entre les mois de mars et décembre 2020. Nous avons comparé la croissance virale en culture cellulaire, les valeurs de cycle seuil de test d'amplification en chaîne par polymérase couplé à une transcription inverse (RT-PCR) de l'enveloppe (E) du gène du SRAS-CoV-2 et de la dose infectieuse pour 50 % de la culture tissulaire (DICT50/mL) entre les adultes et les enfants. RÉSULTATS: Parmi les 305 échantillons positifs à la présence du SRAS-CoV-2 validés par RT-PCR, 97 échantillons provenaient d'enfants de 10 ans et moins, 78 échantillons d'enfants de 11­17 ans et 130 échantillons d'adultes (≥ 18 ans). On a observé une croissance virale en culture dans 31 % des échantillons, dont 18 (19 %) échantillons d'enfants de 10 ans et moins, 18 (23 %) d'enfants de 11­17 ans et 57 (44 %) d'adultes (enfants c. adultes, rapport de cotes 0,45; intervalle de confiance [IC] à 95 % 0,28­0,72). Le cycle seuil était de 25,1 (IC à 95 % 17,7­31,3) chez les enfants de 10 ans et moins, 22,2 (IC à 95 % 18,3­29,0) chez les enfants de 11­17 ans et 18,7 (IC à 95 % 17,9­30,4) chez les adultes (p < 0,001). La DICT50/mL médiane était considérablement plus faible chez les enfants de 11­17 ans (316, écart interquartile [EI] 178­2125) que chez les adultes (5620, EI 1171­17 800, p < 0,001). Le cycle seuil était un indicateur exact d'une culture positive chez les enfants et les adultes (aire sous la courbe de la fonction d'efficacité du récepteur, 0,87, IC à 95 % 0,81­0,93 c. 0,89, IC à 95 % 0,83­0,96, p = 0,6). INTERPRÉTATION: Comparés aux adultes, les enfants qui ont obtenu un résultat positif à un test de dépistage du SRAS-CoV-2 à l'aide d'un écouvillon nasopharyngé étaient moins susceptibles de présenter une croissance du virus en culture et obtenaient un cycle seuil plus élevé et une concentration virale moins élevée, indiquant que les enfants ne sont pas les principaux vecteurs de la transmission du SRAS-CoV-2.

A randomized controlled trial on the effects of goal-directed therapy on the inflammatory response open abdominal aortic aneurysm repair.

INTRODUCTION: Goal-directed therapy (GDT) has been shown in numerous studies to decrease perioperative morbidity and mortality. The mechanism of benefit of GDT, however, has not been clearly elucidated. Targeted resuscitation of the vascular endothelium with GDT might alter the postoperative inflammatory response and be responsible for the decreased complications with this therapy. METHODS: This trial was registered at ClinicalTrials.gov as NCT01681251. Forty patients undergoing elective open repair of their abdominal aortic aneurysm, 18 years of age and older, were randomized to an interventional arm with GDT targeting stroke volume variation with an arterial pulse contour cardiac output monitor, or control, where fluid therapy was administered at the discretion of the attending anesthesiologist. We measured levels of several inflammatory cytokines (C-reactive protein, Pentraxin 3, suppressor of tumorgenicity--2, interleukin-1 receptor antagonist, and tumor necrosis factor receptor-III) preoperatively and at several postoperative time points to determine if there was a difference in inflammatory response. We also assessed each group for a composite of postoperative complications. RESULTS: Twenty patients were randomized to GDT and twenty were randomized to control. Length of stay was not different between groups. Intervention patients received less crystalloid and more colloid. At the end of the study, intervention patients had a higher cardiac index (3.4 ± 0.5 vs. 2.5 ± 0.7 l/minute per m(2), p < 0.01) and stroke volume index (50.1 ± 7.4 vs. 38.1 ± 9.8 ml/m(2), p < 0.01) than controls. There were significantly fewer complications in the intervention than control group (28 vs. 12, p = 0.02). The length of hospital and ICU stay did not differ between groups. There was no difference in the levels of inflammatory cytokines between groups. CONCLUSIONS: Despite being associated with fewer complications and improved hemodynamics, there was no difference in the inflammatory response of patients treated with GDT. This suggests that the clinical benefit of GDT occurs in spite of a similar inflammatory burden. Further work needs to be performed to delineate the mechanism of benefit of GDT. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01681251 . Registered 18 May 2011.

Ebola virus disease: an update for anesthesiologists and intensivists.

PURPOSE: Ebola virus disease (EVD) is a viral hemorrhagic fever that is highly transmissible and all too often rapidly fatal. Recent outbreaks in West Africa reveal that this infection has the potential to be transmitted worldwide. Anesthesiologists and intensivists, due to their training in the management of the critically ill, may be called upon to assist in the management of these patients. The focus of this brief review is on the epidemiology, pathogenesis, and management of patients with EVD. SOURCE: Review of the current literature. PRINCIPAL FINDINGS: Ebola virus disease causes severe diarrhea, electrolyte disturbances and other major end-organ dysfunction. Early aggressive resuscitation may reduce the mortality of this disease. There is presently no available vaccine nor cure, with experimental therapies having yielded limited success. Personal protective equipment (PPE) is necessary for all patient contact, and enhanced PPE is required for all aerosol-generating medical procedures. CONCLUSION: Anesthesiologists and intensivists may be called upon to manage patients with EVD. It is important that these clinicians have an appreciation for the epidemiology and pathogenesis of this disease and for the proper utilization of PPE when treating these patients.

Ethical concerns for anesthesiologists during an Ebola threat.

PURPOSE: The World Health Organization has proclaimed the current Ebola outbreak as a public health emergency. If an outbreak of Ebola should occur in Canada, anesthesiologists and anesthesia departments may be called upon to respond. The purpose of this review is to highlight and discuss potential ethical concepts that may be relevant to anesthesiologists. SOURCE: A thorough literature search was conducted using a variety of MEDLINE® sources, and we used Stand on Guard for Thee. Ethical Considerations in Preparedness Planning for Pandemic Influenza, a report by The University of Toronto Joint Centre for Bioethics Pandemic Influenza Working Group, as the framework for our review. PRINCIPAL FINDINGS: Two groups of ethical concerns were identified. The first group relates to public health ethics, which analyzes the morality of public health interventions, and the second group relates to medical ethics, particularly to "the duty to care". The Canadian Medical Association Code of Ethics is vague in the description of duties of physicians who may respond to high-risk contagious diseases. CONCLUSIONS: Government, public health authorities, and anesthesia departments need to be prepared to respond to an outbreak of Ebola. Anesthesiologists have a skill that is suited to treat the complications of Ebola virus disease, and in case they are called for duty, anesthesiologists should be aware of the ethical concerns of treating a highly contagious communicable disease.

Acute Kidney Injury in Patients Undergoing Open Abdominal Aortic Aneurysm Repair: A Pilot Observational Trial.

OBJECTIVES: Acute kidney injury (AKI) is a frequent complication after open repair of abdominal aortic aneurysms (AAA). Little research has been done to determine whether intraoperative hemodynamic events may precipitate AKI. Novel biomarkers also may aid in the earlier diagnosis of AKI. DESIGN: A pilot prospective observational trial. SETTING: A single tertiary academic medical center. PARTICIPANTS: Participants were 40 adult patients undergoing open repair of infrarenal AAA. INTERVENTIONS: Intraoperative hemodynamic monitoring of heart rate, mean arterial pressure, central venous pressure, and cardiac index was performed on a continuous basis. Blood samples were obtained at baseline and at 24 hours postoperatively for inflammatory biomarkers, including neutrophil gelatinase-associated lipocalin (NGAL). MEASUREMENTS AND MAIN RESULTS: AKI occurred in 20% of patients (8 of 40). Hypotension, including duration (defined as the length of time mean arterial pressure was<65 mmHg) and magnitude (the area under the curve of a mean arterial pressure<65 mmHg), was the only factor associated with postoperative AKI. Urinary NGAL at the conclusion of surgery had excellent ability to predict the development of AKI (area under the curve 0.84, 95% confidence interval = 0.70-0.97). The cytokines pentraxin 3 (PTX3), interleukin-1 receptor antagonist (IL1-RA), macrophage chemotactic protein (MCP), suppressor of tumorigenicity 2 (ST-2), and interleukin-10 (IL-10) also had good ability to predict the development of AKI in the immediate postoperative period. CONCLUSIONS: AKI occurs frequently in patients undergoing open repair of AAA. Intraoperative hypotension was the only factor that predicted the development of subsequent AKI. Urinary NGAL and several novel inflammatory biomarkers demonstrated good ability to predict its development. Novel biomarkers also may aid in the early diagnosis of AKI.

Low-dose corticosteroid treatment in septic shock: a propensity-matching study.

OBJECTIVE: Given conflicting data and current guidelines, low-dose corticosteroids are often used in the treatment of septic shock. To evaluate the therapeutic benefit of early low-dose corticosteroid in patients with septic shock. DESIGN: Retrospective, multicenter, propensity-matched cohort study. SETTING: ICUs of 28 academic and community hospitals in three countries between 1996 and 2007. SUBJECTS: Six thousand six hundred sixty-three eligible patients with septic shock of whom 1,838 received IV low-dose corticosteroid treatment within 48 hours of the diagnosis of septic shock and were matched to a comparable group who did not receive low-dose corticosteroid. MEASUREMENTS AND MAIN RESULTS: The primary outcome was 30-day mortality. Mortality analyses were stratified by severity of illness (Acute Physiology and Chronic Health Evaluation II quartile). Using a Cox proportional hazards model, corticosteroid therapy was associated with similar 30-day mortality when compared with the matched control cohort (652/1,838 [35.5%] vs 641/1,838 [34.9%]; hazard ratio, 0.98; 95% CI, 0.88-1.10; p = 0.77). In the subgroup of patients with the Acute Physiology and Chronic Health Evaluation II score quartile more than or equal to 30, low-dose corticosteroid was associated with lower mortality (232/461 [50.6%] vs 251/450 [55.8%]; hazard ratio, 0.81; 95% CI, 0.68-0.97; p = 0.02). In logistic regression models, corticosteroid therapy was not associated with reductions in ICU (556/1,838 [30.3%] vs 558/1,838 [30.4%]; odds ratio, 0.99; 95% CI, 0.86-1.15; p = 0.94) or hospital mortality (797/1,838 [43.4%] vs 773/1,838 [42.1%]; odds ratio, 1.05; 95% CI, 0.93-1.20; p = 0.42). Similarly, there were no significant differences in ventilator- (median and interquartile range, 13 [0-25] vs 15 [0-25]; p = 0.8) and pressor/inotrope-free days (median and interquartile range, 25 [3-27] vs 24 [2-28]; p = 0.63) up to 30 days between groups. CONCLUSION: Early administration of low-dose corticosteroid is not associated with decreased mortality when it is administered to unselected patients with septic shock. A beneficial effect of low-dose corticosteroid on mortality may exist in patients with the highest severity of illness. Future trials of low-dose corticosteroid in septic shock should consider restricting the study population to this cohort.

Identification of four latent classes of acute respiratory distress syndrome using PaO2/FIO2 ratio: an observational cohort study.

Biological phenotypes in patients with the acute respiratory distress syndrome (ARDS) have previously been described. We hypothesized that the trajectory of PaO2/FIO2 ratio could be used to identify phenotypes of ARDS. We used a retrospective cohort analysis of an ARDS database to identify latent classes in the trajectory of PaO2/FIO2 ratio over time. We included all adult patients admitted to an intensive care unit who met the Berlin criteria for ARDS over a 4-year period in tertiary adult intensive care units in Manitoba, Canada. Baseline demographics were collected along with the daily PaO2/FIO2 ratio collected on admission and on days 1-7, 14 and 28. We used joint growth mixture modeling to test whether ARDS patients exhibit distinct phenotypes with respect to both longitudinal PaO2/FIO2 ratio and survival. The resulting latent classes were compared on several demographic variables. In our study group of 209 patients, we found that four latent trajectory classes of PaO2/FIO2 ratio was optimal. These four classes differed in their baseline PaO2/FIO2 ratio and their trajectory of improvement during the 28 days of the study. Despite similar baseline characteristics the hazard for death for the classes differed over time. This difference was largely driven by withdrawal of life sustaining therapy in one of the classes. Latent classes were identified in the trajectory of the PaO2/FIO2 ratio over time, suggesting the presence of different ARDS phenotypes. Future studies should confirm the existence of this finding and determine the cause of mortality differences between classes.

Role of the venous return in critical illness and shock: part II-shock and mechanical ventilation.

OBJECTIVE: To provide a conceptual and clinical review of the physiology of the venous system as it is related to cardiac function in health and disease. DATA: An integration of venous and cardiac physiology under normal conditions, critical illness, and resuscitation. SUMMARY: The usual clinical teaching of cardiac physiology focuses on left ventricular pathophysiology and pathology. Due to the wide array of shock states dealt with by intensivists, an integrated approach that takes into account the function of the venous system and its interaction with the right heart may be more useful. In part II of this two-part review, we describe the physiology of venous return and its interaction with the right heart function as it relates to mechanical ventilation and various shock states including hypovolemic, cardiogenic, obstructive, and septic shock. In particular, we demonstrate how these shock states perturb venous return/right heart interactions. We also show how compensatory mechanisms and therapeutic interventions can tend to return venous return and cardiac output to appropriate values. CONCLUSION: An improved understanding of the role of the venous system in pathophysiologic conditions will allow intensivists to better appreciate the complex circulatory physiology of shock and related therapies. This should enable improved hemodynamic management of this disorder.

The role of venous return in critical illness and shock-part I: physiology.

OBJECTIVE: To provide a conceptual and clinical review of the physiology of the venous system as it is relates to cardiac function in health and disease. DATA: An integration of venous and cardiac physiology under normal conditions, critical illness, and resuscitation. SUMMARY: The usual teaching of cardiac physiology focuses on left ventricular function. As a result of the wide array of shock states with which intensivists contend, an approach that takes into account the function of the venous system and its interaction with the right and left heart may be more useful. This two-part review focuses on the function of the venous system and right heart under normal and stressed conditions. The first part describes the basic physiology of the venous system, and part two focuses on the role of the venous system in different pathophysiologic states, particularly shock. CONCLUSION: An improved understanding of the role of the venous system in health and disease will allow intensivists to better appreciate the complex circulatory physiology of shock and may allow for better hemodynamic management of this disorder.

Cerebral oxygen desaturation during one-lung ventilation: correlation with hemodynamic variables.

PURPOSE: Cerebral desaturation occurs frequently in patients undergoing one-lung ventilation for thoracic surgery. The mechanism of this desaturation is unclear regarding its etiology. The objective of this study was to investigate whether or not decreases in cerebral oxygen saturation associated with one-lung ventilation were a consequence of decreased cardiac output. METHODS: A blinded observational study was conducted in 23 patients undergoing one-lung ventilation with thoracic surgery. Eighteen patients completed the study. Cerebral oxygen saturation was monitored using near-infrared spectroscopy (FORE-SIGHT(®) monitor). Invasive blood pressure was monitored and hemodynamic variables were interrogated using the FloTrac(®) system. Anesthesia was maintained with sevoflurane with a F(i)O(2) of 1.0. Post-hoc analysis involved a comparison between baseline and integrated changes in cerebral saturation, heart rate, stroke index, cardiac index, and stroke volume variability. RESULTS: All patients showed cerebral desaturation from a baseline of two-lung ventilation in the lateral decubitus position following institution of one-lung ventilation. The cardiac index was stable at these times, but with one-lung ventilation, the heart rate decreased and the stroke index increased to maintain a stable product. The integral of heart rate × time was inversely correlated with the integral of cerebral desaturation × time (linear regression analysis; P = 0.02; (df) = 16)). CONCLUSIONS: Cerebral oxygen desaturation was universal during one-lung ventilation in this study. There was no correlation between cerebral desaturation and cardiac output or other hemodynamic variables.

A prospective observational study comparing outcomes before and after the introduction of an intubation protocol during the COVID-19 pandemic.

OBJECTIVE: Orotracheal intubation is a life-saving procedure commonly performed in the Intensive Care unit and Emergency Department as a part of emergency airway management. Prior to the COVID-19 pandemic, our center undertook a prospective observational study to characterize emergency intubation performed in the emergency department and critical care settings at Manitoba's largest tertiary hospital. During this study, a natural experiment emerged when a standardized "COVID-Protected Rapid Sequence Intubation Protocol" was implemented in response to the pandemic. The resultant study aimed to answer the question; in adult ED patients undergoing emergent intubation by EM and CCM teams, does the use of a "COVID-Protected Rapid Sequence Intubation Protocol" impact first-pass success or other intubation-related outcomes? METHODS: A single-center prospective quasi-experimental before and after study was conducted. Data were prospectively collected on consecutive emergent intubations. The primary outcome was the difference in first-pass success rates. Secondary outcomes included best Modified Cormack-Lehane view, hypoxemia, hypotension, esophageal intubation, cannot intubate cannot oxygenate scenarios, CPR post intubation, vasopressors required post intubation, Intensive Care Unit (ICU) mortality, ICU length of stay (LOS), and mechanical ventilation days. RESULTS: Data were collected on 630 patients, 416 in the pre-protocol period and 214 in the post-protocol period. First-pass success rates in the pre-protocol period were found to be 73.1% (n = 304). Following the introduction of the protocol, first-pass success rates increased to 82.2% (n = 176, p = 0.0105). There was a statistically significant difference in Modified Cormack-Lehane view favoring the protocol (p = 0.0191). Esophageal intubation rates were found to be 5.1% pre-protocol introduction versus 0.5% following the introduction of the protocol (p = 0.0172). CONCLUSION: A "COVID-Protected Protocol" implemented by Emergency Medicine and Critical Care teams in response to the COVID-19 pandemic was associated with increased first-pass success rates and decreases in adverse events.

RéSUMé: OBJECTIFS: L'intubation orotrachéale est une procédure de sauvetage couramment réalisée dans l'unité de soins intensifs et le service des urgences dans le cadre de la gestion des voies aériennes d'urgence. Avant la pandémie de COVID-19, notre centre a entrepris une étude prospective d'observation pour caractériser l'intubation d'urgence effectuée dans le service des urgences et les établissements de soins intensifs du plus grand hôpital tertiaire du Manitoba. Au cours de cette étude, une expérience naturelle est apparue lorsqu'un " protocole d'intubation à séquence rapide protégé contre le COVID " standardisé a été mis en œuvre en réponse à la pandémie. L'étude qui en a résulté visait à répondre à la question suivante : chez les patients adultes des urgences soumis à une intubation urgente par les équipes de médecine d'urgence et de médecine de soins critiques, l'utilisation d'un " protocole d'intubation à séquence rapide protégé par COVID " a-t-elle un impact sur la réussite du premier passage ou sur d'autres résultats liés à l'intubation ? MéTHODE: Une étude prospective quasi-expérimentale avant et après a été menée dans un seul centre. Les données ont été recueillies prospectivement sur des intubations émergentes consécutives. Le résultat principal était la différence entre les taux de réussite au premier passage. Les résultats secondaires comprenaient la meilleure vue de Cormack­Lehane modifiée, l'hypoxémie, l'hypotension, l'intubation œsophagienne, les scénarios d'impossibilité d'intubation et d'oxygénation, la réanimation cardio-pulmonaire après l'intubation, les vasopresseurs nécessaires après l'intubation, la mortalité en unité de soins intensifs (USI), la durée de séjour en USI et les jours de ventilation mécanique. RéSULTATS: Des données ont été recueillies sur 630 patients, 416 dans la période pré-protocole et 214 dans la période post-protocole. Les taux de réussite au premier passage dans la période pré-protocole se sont avérés être de 73,1 % (n = 304). Suite à l'introduction du protocole, les taux de réussite au premier passage ont augmenté à 82,2 % (n = 176, p = 0,0105). Il y avait une différence statistiquement significative dans la vue Cormack­Lehane modifiée en faveur du protocole (p = 0,0191). Les taux d'intubation œsophagienne se sont avérés être de 5,1 % avant l'introduction du protocole contre 0,5 % après l'introduction du protocole (p = 0,0172). CONCLUSION: Un « protocole protégé contre la COVID ¼ mis en œuvre par les équipes de médecine d'urgence et de médecine de soins critiques en réponse à la pandémie de COVID-19 a été associé à une augmentation des taux de réussite du premier passage et à une diminution des événements indésirables.