One-year Outcomes after Discharge from Noncardiac Surgery and Association between Predischarge Complications and Death after Discharge: Analysis of the VISION Prospective Cohort Study.

BACKGROUND: In previous analyses, myocardial injury after noncardiac surgery, major bleeding, and sepsis were independently associated with most deaths in the 30 days after noncardiac surgery, but most of these deaths occurred during the index hospitalization for surgery. The authors set out to describe outcomes after discharge from hospital up to 1 yr after inpatient noncardiac surgery and associations between predischarge complications and postdischarge death up to 1 yr after surgery. METHODS: This study was an analysis of patients discharged after inpatient noncardiac surgery in a large international prospective cohort study across 28 centers from 2007 to 2013 of patients aged 45 yr or older followed to 1 yr after surgery. The study estimated (1) the cumulative postdischarge incidence of death and other outcomes up to a year after surgery and (2) the adjusted time-varying associations between postdischarge death and predischarge complications including myocardial injury after noncardiac surgery, major bleeding, sepsis, infection without sepsis, stroke, congestive heart failure, clinically important atrial fibrillation or flutter, amputation, venous thromboembolism, and acute kidney injury managed with dialysis. RESULTS: Among 38,898 patients discharged after surgery, the cumulative 1-yr incidence was 5.8% (95% CI, 5.5 to 6.0%) for all-cause death and 24.7% (95% CI, 24.2 to 25.1%) for all-cause hospital readmission. Predischarge complications were associated with 33.7% (95% CI, 27.2 to 40.2%) of deaths up to 30 days after discharge and 15.0% (95% CI, 12.0 to 17.9%) up to 1 yr. Most of the association with death was due to myocardial injury after noncardiac surgery (15.6% [95% CI, 9.3 to 21.9%] of deaths within 30 days, 6.4% [95% CI, 4.1 to 8.7%] within 1 yr), major bleeding (15.0% [95% CI, 8.3 to 21.7%] within 30 days, 4.7% [95% CI, 2.2 to 7.2%] within 1 yr), and sepsis (5.4% [95% CI, 2.2 to 8.6%] within 30 days, 2.1% [95% CI, 1.0 to 3.1%] within 1 yr). CONCLUSIONS: One in 18 patients 45 yr old or older discharged after inpatient noncardiac surgery died within 1 yr, and one quarter were readmitted to the hospital. The risk of death associated with predischarge perioperative complications persists for weeks to months after discharge.

Myocardial Injury After Noncardiac Surgery in Major General Surgical Patients a Prospective Observational Cohort Study.

OBJECTIVE: The objective of this study was to determine the prognostic relevance, clinical characteristics, and 30-day outcomes associated with myocardial injury after noncardiac surgery (MINS) in major general surgery patients. BACKGROUND: MINS has been independently associated with 30-day mortality after noncardiac surgery. The characteristics and prognostic importance of MINS in major general surgical patients have not been described. METHODS: This was an international prospective cohort study of a representative sample of 22,552 noncardiac surgery patients 45 years or older, of whom 4490 underwent major general surgery in 24 centers in 13 countries. All patients had fifth-generation plasma high-sensitivity troponin T (hsTnT) concentrations measured during the first 3 postoperative days. MINS was defined as a hsTnT of 20-65 ng/L and absolute change >5 ng/L or hsTnT ≥65 ng/L secondary to ischemia. The objectives of the present study were to determine (1) whether MINS is prognostically important in major general surgical patients, (2) the clinical characteristics of major general surgical patients with and without MINS, (3) the 30-day outcomes for major general surgical patients with and without MINS, and (4) the proportion of MINS that would have gone undetected without routine postoperative monitoring. RESULTS: The incidence of MINS in the major general surgical patients was 16.3% (95% CI, 15.3-17.4%). Thirty-day all-cause mortality in the major general surgical cohort was 6.8% (95% CI, 5.1%-8.9%) in patients with MINS compared with 1.2% (95% CI, 0.9%-1.6%) in patients without MINS ( P <0.01). MINS was independently associated with 30-day mortality in major general surgical patients (adjusted odds ratio 4.7, 95% CI, 3.0-7.4). The 30-day mortality was higher both among MINS patients with no ischemic features (ie, no ischemic symptoms or electrocardiogram findings) (5.4%, 95% CI, 3.7%-7.7%) and among patients with 1 or more clinical ischemic features (10.6%, 95% CI, 6.7%-15.8%). The proportion of major general surgical patients who had MINS without ischemic symptoms was 89.9% (95% CI, 87.5-92.0). CONCLUSIONS: Approximately 1 in 6 patients experienced MINS after major general surgery. MINS was independently associated with a nearly 5-fold increase in 30-day mortality. The vast majority of patients with MINS were asymptomatic and would have gone undetected without routine postoperative troponin measurement.

In COVID-19 with hypoxemia, 12 vs. 6 mg/d of dexamethasone did not increase days alive without life support.

SOURCE CITATION: Munch MW, Myatra SN, Vijayaraghavan BK, et al. Effect of 12 mg vs 6 mg of dexamethasone on the number of days alive without life support in adults with COVID-19 and severe hypoxemia: the COVID STEROID 2 randomized trial. JAMA. 2021;326:1807-17. 34673895.

Myocardial Injury After Noncardiac Surgery (MINS) in Vascular Surgical Patients: A Prospective Observational Cohort Study.

OBJECTIVE: To determine the prognostic relevance, clinical characteristics, and 30-day outcomes associated with myocardial injury after noncardiac surgery (MINS) in vascular surgical patients. BACKGROUND: MINS has been independently associated with 30-day mortality after noncardiac surgery. The characteristics and prognostic importance of MINS in vascular surgery patients are poorly described. METHODS: This was an international prospective cohort study of 15,102 noncardiac surgery patients 45 years or older, of whom 502 patients underwent vascular surgery. All patients had fourth-generation plasma troponin T (TnT) concentrations measured during the first 3 postoperative days. MINS was defined as a TnT of 0.03 ng/mL of higher secondary to ischemia. The objectives of the present study were to determine (i) if MINS is prognostically important in vascular surgical patients, (ii) the clinical characteristics of vascular surgery patients with and without MINS, (iii) the 30-day outcomes for vascular surgery patients with and without MINS, and (iv) the proportion of MINS that probably would have gone undetected without routine troponin monitoring. RESULTS: The incidence of MINS in the vascular surgery patients was 19.1% (95% confidence interval (CI), 15.7%-22.6%). 30-day all-cause mortality in the vascular cohort was 12.5% (95% CI 7.3%-20.6%) in patients with MINS compared with 1.5% (95% CI 0.7%-3.2%) in patients without MINS (P < 0.001). MINS was independently associated with 30-day mortality in vascular patients (odds ratio, 9.48; 95% CI, 3.46-25.96). The 30-day mortality was similar in MINS patients with (15.0%; 95% CI, 7.1-29.1) and without an ischemic feature (12.2%; 95% CI, 5.3-25.5, P = 0.76). The proportion of vascular surgery patients who suffered MINS without overt evidence of myocardial ischemia was 74.1% (95% CI, 63.6-82.4). CONCLUSIONS: Approximately 1 in 5 patients experienced MINS after vascular surgery. MINS was independently associated with 30-day mortality. The majority of patients with MINS were asymptomatic and would have gone undetected without routine postoperative troponin measurement.

Age Does Not Affect Metoprolol's Effect on Perioperative Outcomes (From the POISE Database).

BACKGROUND: Perioperative ß-blockade reduces the incidence of myocardial infarction but increases that of death, stroke, and hypotension. The elderly may experience few benefits but more harms associated with ß-blockade due to a normal effect of aging, that of a reduced resting heart rate. The tested hypothesis was that the effect of perioperative ß-blockade is more significant with increasing age. METHODS: To determine whether the effect of perioperative ß-blockade on the primary composite event, clinically significant hypotension, myocardial infarction, stroke, and death varies with age, we interrogated data from the perioperative ischemia evaluation (POISE) study. The POISE study randomly assigned 8351 patients, aged ≥45 years, in 23 countries, undergoing major noncardiac surgery to either 200 mg metoprolol CR daily or placebo for 30 days. Odds ratios or hazard ratios for time to events, when available, for each of the adverse effects were measured according to decile of age, and interaction term between age and treatment was calculated. No adjustment was made for multiple outcomes. RESULTS: Age was associated with higher incidences of the major outcomes of clinically significant hypotension, myocardial infarction, and death. Age was associated with a minimal reduction in resting heart rate from 84.2 (standard error, 0.63; ages 45-54 years) to 80.9 (standard error, 0.70; ages >85 years; P < .0001). We found no evidence of any interaction between age and study group regarding any of the major outcomes, although the limited sample size does not exclude any but large interactions. CONCLUSIONS: The effect of perioperative ß-blockade on the major outcomes studied did not vary with age. Resting heart rate decreases slightly with age. Our data do not support a recommendation for the use of perioperative ß-blockade in any age subgroup to achieve benefits but avoid harms. Therefore, current recommendations against the use of ß-blockers in high-risk patients undergoing noncardiac surgery apply across all age groups.

Troponin T monitoring to detect myocardial injury after noncardiac surgery: a cost-consequence analysis.

BACKGROUND: Myocardial injury after noncardiac surgery (MINS) is a mostly asymptomatic condition that is strongly associated with 30-day mortality; however, it remains mostly undetected without systematic troponin T monitoring. We evaluated the cost and consequences of postoperative troponin T monitoring to detect MINS. METHODS: We conducted a model-based cost-consequence analysis to compare the impact of routine troponin T monitoring versus standard care (troponin T measurement triggered by ischemic symptoms) on the incidence of MINS detection. Model inputs were based on Canadian patients enrolled in the Vascular Events in Noncardiac Surgery Patients Cohort Evaluation (VISION) study, which enrolled patients aged 45 years or older undergoing inpatient noncardiac surgery. We conducted probability analyses with 10 000 iterations and extensive sensitivity analyses. RESULTS: The data were based on 6021 patients (48% men, mean age 65 [standard deviation 12] yr). The 30-day mortality rate for MINS was 9.6%. We determined the incremental cost to avoid missing a MINS event as $1632 (2015 Canadian dollars). The cost-effectiveness of troponin monitoring was higher in patient subgroups at higher risk for MINS, e.g., those aged 65 years or more, or with a history of atherosclerosis or diabetes ($1309). CONCLUSION: The costs associated with a troponin T monitoring program to detect MINS were moderate. Based on the estimated incremental cost per health gain, implementation of postoperative troponin T monitoring seems appealing, particularly in patients at high risk for MINS.

CONTEXTE: Les lésions myocardiques après chirurgie non cardiaque (CNC) sont majoritairement asymptomatiques et fortement associées au risque de mortalité dans les 30 jours; toutefois, dans la plupart des cas, elles ne sont pas détectées en l'absence d'une surveillance systématique de la troponine T. Nous avons évalué les coûts et les conséquences d'une telle surveillance pour détecter les lésions myocardiques après CNC. MÉTHODES: Nous avons mené une analyse coût-conséquence modélisée pour comparer la surveillance systématique de la troponine T aux soins habituels seuls (mesure de la troponine T seulement s'il y a présence de symptômes d'ischémie) sur la fréquence de détection de lésions myocardiques après CNC. Les données ayant servi à l'analyse provenaient des patients canadiens ayant participé à l'étude de cohorte VISION, qui visait à évaluer les complications vasculaires chez les patients de 45 ans et plus ayant subi une CNC. Nous avons mené des analyses de probabilité avec 10  000 itérations et des analyses de sensibilité approfondies. RÉSULTATS: Les données portaient sur 6021 patients (48 % du sexe masculin; âge moyen de 65 ans [écart-type de 12 ans]). Le taux de mortalité dans les 30 jours associé à une lésion myocardique après CNC était de 9,6 %. Nous avons déterminé que le coût marginal de la détection de la présence d'une lésion par surveillance de la troponine T était de 1632 $ (dollars canadiens en 2015). Le rapport coût-efficacité était plus bas pour les sous-groupes de patients à risque élevé de lésion myocardique après CNC, comme les patients de 65 ans et plus ou ceux ayant des antécédents d'athérosclérose ou de diabète (1309 $), que pour leurs pairs. CONCLUSION: Les coûts associés à un programme de surveillance de la troponine T pour détecter les lésions myocardiques après CNC étaient modérés. Le coût marginal estimé par gain de santé indique que la mise en œuvre de ce type de programme pourrait être une option intéressante, surtout pour les patients à risque élevé de lésion myocardique après CNC.

Association of Postoperative High-Sensitivity Troponin Levels With Myocardial Injury and 30-Day Mortality Among Patients Undergoing Noncardiac Surgery.

IMPORTANCE: Little is known about the relationship between perioperative high-sensitivity troponin T (hsTnT) measurements and 30-day mortality and myocardial injury after noncardiac surgery (MINS). OBJECTIVE: To determine the association between perioperative hsTnT measurements and 30-day mortality and potential diagnostic criteria for MINS (ie, myocardial injury due to ischemia associated with 30-day mortality). DESIGN, SETTING, AND PARTICIPANTS: Prospective cohort study of patients aged 45 years or older who underwent inpatient noncardiac surgery and had a postoperative hsTnT measurement. Starting in October 2008, participants were recruited at 23 centers in 13 countries; follow-up finished in December 2013. EXPOSURES: Patients had hsTnT measurements 6 to 12 hours after surgery and daily for 3 days; 40.4% had a preoperative hsTnT measurement. MAIN OUTCOMES AND MEASURES: A modified Mazumdar approach (an iterative process) was used to determine if there were hsTnT thresholds associated with risk of death and had an adjusted hazard ratio (HR) of 3.0 or higher and a risk of 30-day mortality of 3% or higher. To determine potential diagnostic criteria for MINS, regression analyses ascertained if postoperative hsTnT elevations required an ischemic feature (eg, ischemic symptom or electrocardiography finding) to be associated with 30-day mortality. RESULTS: Among 21 842 participants, the mean age was 63.1 (SD, 10.7) years and 49.1% were female. Death within 30 days after surgery occurred in 266 patients (1.2%; 95% CI, 1.1%-1.4%). Multivariable analysis demonstrated that compared with the reference group (peak hsTnT <5 ng/L), peak postoperative hsTnT levels of 20 to less than 65 ng/L, 65 to less than 1000 ng/L, and 1000 ng/L or higher had 30-day mortality rates of 3.0% (123/4049; 95% CI, 2.6%-3.6%), 9.1% (102/1118; 95% CI, 7.6%-11.0%), and 29.6% (16/54; 95% CI, 19.1%-42.8%), with corresponding adjusted HRs of 23.63 (95% CI, 10.32-54.09), 70.34 (95% CI, 30.60-161.71), and 227.01 (95% CI, 87.35-589.92), respectively. An absolute hsTnT change of 5 ng/L or higher was associated with an increased risk of 30-day mortality (adjusted HR, 4.69; 95% CI, 3.52-6.25). An elevated postoperative hsTnT (ie, 20 to <65 ng/L with an absolute change ≥5 ng/L or hsTnT ≥65 ng/L) without an ischemic feature was associated with 30-day mortality (adjusted HR, 3.20; 95% CI, 2.37-4.32). Among the 3904 patients (17.9%; 95% CI, 17.4%-18.4%) with MINS, 3633 (93.1%; 95% CI, 92.2%-93.8%) did not experience an ischemic symptom. CONCLUSIONS AND RELEVANCE: Among patients undergoing noncardiac surgery, peak postoperative hsTnT during the first 3 days after surgery was significantly associated with 30-day mortality. Elevated postoperative hsTnT without an ischemic feature was also associated with 30-day mortality.

Cost-effectiveness of dalteparin vs unfractionated heparin for the prevention of venous thromboembolism in critically ill patients.

IMPORTANCE: Venous thromboembolism (VTE) is a common complication of acute illness, and its prevention is a ubiquitous aspect of inpatient care. A multicenter blinded, randomized trial compared the effectiveness of the most common pharmocoprevention strategies, unfractionated heparin (UFH) and the low-molecular-weight heparin (LMWH) dalteparin, finding no difference in the primary end point of leg deep-vein thrombosis but a reduced rate of pulmonary embolus and heparin-induced thrombocytopenia among critically ill medical-surgical patients who received dalteparin. OBJECTIVE: To evaluate the comparative cost-effectiveness of LMWH vs UFH for prophylaxis against VTE in critically ill patients. DESIGN, SETTING, AND PARTICIPANTS: Prospective economic evaluation concurrent with the Prophylaxis for Thromboembolism in Critical Care Randomized Trial (May 2006 to June 2010). The economic evaluation adopted a health care payer perspective and in-hospital time horizon; derived baseline characteristics and probabilities of intensive care unit and in-hospital events; and measured costs among 2344 patients in 23 centers in 5 countries and applied these costs to measured resource use and effects of all enrolled patients. MAIN OUTCOMES AND MEASURES: Costs, effects, incremental cost-effectiveness of LMWH vs UFH during the period of hospitalization, and sensitivity analyses across cost ranges. RESULTS: Hospital costs per patient were $39,508 (interquartile range [IQR], $24,676 to $71,431) for 1862 patients who received LMWH compared with $40,805 (IQR, $24,393 to $76,139) for 1862 patients who received UFH (incremental cost, -$1297 [IQR, -$4398 to $1404]; P = .41). In 78% of simulations, a strategy using LMWH was most effective and least costly. In sensitivity analyses, a strategy using LMWH remained least costly unless the drug acquisition cost of dalteparin increased from $8 to $179 per dose and was consistent among higher- and lower-spending health care systems. There was no threshold at which lowering the acquisition cost of UFH favored prophylaxis with UFH. CONCLUSIONS AND RELEVANCE: From a health care payer perspective, the use of the LMWH dalteparin for VTE prophylaxis among critically ill medical-surgical patients was more effective and had similar or lower costs than the use of UFH. These findings were driven by lower rates of pulmonary embolus and heparin-induced thrombocytopenia and corresponding lower overall use of resources with LMWH.

Mortality and major postoperative complications within 1 year after vascular surgery: a prospective cohort study.

INTRODUCTION: Patients undergoing vascular procedures are prone to developing postoperative complications affecting their short­term mortality. Prospective reports describing the incidence of long­term complications after vascular surgery are lacking. OBJECTIVES: We aimed to describe the incidence of complications 1 year after vascular surgery and to evaluate an association between myocardial injury after noncardiac surgery (MINS) and 1­year mortality. PATIENTS AND METHODS: This is a substudy of a large prospective cohort study Vascular Events in Noncardiac Surgery Patients Cohort Evaluation (VISION). Recruitment took place in 28 centers across 14 countries from August 2007 to November 2013. We enrolled patients aged 45 years or older undergoing vascular surgery, receiving general or regional anesthesia, and hospitalized for at least 1 night postoperatively. Plasma cardiac troponin T concentration was measured before the surgery and on the first, second, and third postoperative day. The patients or their relatives were contacted 1 year after the procedure to assess the incidence of major postoperative complications. RESULTS: We enrolled 2641 patients who underwent vascular surgery, 2534 (95.9%) of whom completed 1­year follow­up. Their mean (SD) age was 68.2 (9.8) years, and the cohort was predominantly male (77.5%). The most frequent 1­year complications were myocardial infarction (224/2534, 8.8%), amputation (187/2534, 7.4%), and congestive heart failure (67/2534, 2.6%). The 1­year mortality rate was 8.8% (223/2534). MINS occurred in 633 patients (24%) and was associated with an increased 1­year mortality (hazard ratio, 2.82; 95% CI, 2.14-3.72; P <0.001). CONCLUSIONS: The incidence of major postoperative complications after vascular surgery is high. The occurrence of MINS is associated with a nearly 3­fold increase in 1­year mortality.

Association between postoperative troponin levels and 30-day mortality among patients undergoing noncardiac surgery.

CONTEXT: Of the 200 million adults worldwide who undergo noncardiac surgery each year, more than 1 million will die within 30 days. OBJECTIVE: To determine the relationship between the peak fourth-generation troponin T (TnT) measurement in the first 3 days after noncardiac surgery and 30-day mortality. DESIGN, SETTING, AND PARTICIPANTS: A prospective, international cohort study that enrolled patients from August 6, 2007, to January 11, 2011. Eligible patients were aged 45 years and older and required at least an overnight hospital admission after having noncardiac surgery. MAIN OUTCOME MEASURES: Patients' TnT levels were measured 6 to 12 hours after surgery and on days 1, 2, and 3 after surgery. We undertook Cox regression analysis in which the dependent variable was mortality until 30 days after surgery, and the independent variables included 24 preoperative variables. We repeated this analysis, adding the peak TnT measurement during the first 3 postoperative days as an independent variable and used a minimum P value approach to determine if there were TnT thresholds that independently altered patients' risk of death. RESULTS: A total of 15,133 patients were included in this study. The 30-day mortality rate was 1.9% (95% CI, 1.7%-2.1%). Multivariable analysis demonstrated that peak TnT values of at least 0.02 ng/mL, occurring in 11.6% of patients, were associated with higher 30-day mortality compared with the reference group (peak TnT ≤ 0.01 ng/mL): peak TnT of 0.02 ng/mL (adjusted hazard ratio [aHR], 2.41; 95% CI, 1.33-3.77); 0.03 to 0.29 ng/mL (aHR, 5.00; 95% CI, 3.72-6.76); and 0.30 ng/mL or greater (aHR, 10.48; 95% CI, 6.25-16.62). Patients with a peak TnT value of 0.01 ng/mL or less, 0.02, 0.03-0.29, and 0.30 or greater had 30-day mortality rates of 1.0%, 4.0%, 9.3%, and 16.9%, respectively. Peak TnT measurement added incremental prognostic value to discriminate those likely to die within 30 days for the model with peak TnT measurement vs without (C index = 0.85 vs 0.81; difference, 0.4; 95% CI, 0.2-0.5; P < .001 for difference between C index values). The net reclassification improvement with TnT was 25.0% (P < .001). CONCLUSION: Among patients undergoing noncardiac surgery, the peak postoperative TnT measurement during the first 3 days after surgery was significantly associated with 30-day mortality.

Intraoperative renal support during liver transplantation.

Acute kidney injury (AKI) is common in liver failure prior to orthotopic liver transplantation (OLT) and may complicate the intraoperative course. We describe the logistics of intraoperative continuous renal replacement therapy (CRRT) during OLT and the associated clinical outcomes. We performed a retrospective review of adult patients (age > 18 years) receiving intraoperative CRRT during OLT at the University of Alberta Hospital between January 1, 1996 and December 31, 2005. Demographic, detailed clinical, and perioperative data, physiologic and laboratory measures, details of renal replacement therapy (RRT) provided, and data on renal recovery and survival were ascertained. Of 636 OLTs, 41 (6.4%) received intraoperative CRRT. The most common indications for OLT in these patients were hepatitis C (34.2%) and alcoholic (29.3%) cirrhosis. The median [interquartile range (IQR)] Model for End-Stage Liver Disease score was 38 (31-43), and 90.2% were classified as Child-Pugh class C. Preoperatively, 70% were in the intensive care unit, 58.5% were mechanically ventilated, and 48.7% required vasopressor support. The median (IQR) duration of intraoperative CRRT was 258 (189-390) minutes, representing 57% of the total operative time. Filter circuit clotting occurred in 40% but was not associated with a shorter CRRT duration (P = 0.41). No other complications were described. CRRT allowed an even or negative intraoperative fluid balance in 92.7%. CRRT was continued in 78% after OLT for a median (IQR) of 5 (3-11) days. Of these, 24 (75%) were transitioned to intermittent hemodialysis for a median (IQR) of 15 (4-39) days. Survival was 97.6% at 1 month and 75.6% at 1 year. Renal recovery to RRT independence occurred in 100% of survivors by 1 year; however, the mean (standard deviation) estimated glomerular filtration rate (eGFR) was 54.7 (19.1) mL/minute/m(2), with 62.1% having an eGFR < 60 mL/minute/m(2). In conclusion, our data suggest that intraoperative CRRT during OLT is achievable and safe. Intraoperative CRRT may be a valuable adjuvant therapy for those with preoperative AKI. Additional investigations are warranted.

The impact of early hypoglycemia and blood glucose variability on outcome in critical illness.

INTRODUCTION: In critical illness, the association of hypoglycemia, blood glucose (BG) variability and outcome are not well understood. We describe the incidence, clinical factors and outcomes associated with an early hypoglycemia and BG variability in critically ill patients. METHODS: Retrospective interrogation of prospectively collected data from the Australia New Zealand Intensive Care Society Adult Patient Database on 66184 adult admissions to 24 intensive care units (ICUs) from 1 January 2000 to 31 December 2005. Primary exposure was hypoglycemia (BG < 4.5 mmol/L) and BG variability (BG < 4.5 and >or= 12.0 mmol/L) within 24 hours of admission. Primary outcome was all-cause mortality. RESULTS: The cumulative incidence of hypoglycemia and BG variability were 13.8% (95% confidence interval (CI) = 13.5 to 14.0; n = 9122) and 2.9% (95%CI = 2.8 to 3.0, n = 1913), respectively. Several clinical factors were associated with both hypoglycemia and BG variability including: co-morbid disease (P < 0.001), non-elective admissions (P < 0.001), higher illness severity (P < 0.001), and primary septic diagnosis (P < 0.001). Hypoglycemia was associated with greater odds of adjusted ICU (odds ratio (OR) = 1.41, 95% CI = 1.31 to 1.54) and hospital death (OR = 1.36, 95% CI = 1.27 to 1.46). Hypoglycemia severity was associated with 'dose-response' increases in mortality. BG variability was associated with greater odds of adjusted ICU (1.5, 95% CI = 1.4 to 1.6) and hospital (1.4, 95% CI = 1.3 to 1.5) mortality, when compared with either hypoglycemia only or neither. CONCLUSIONS: In critically ill patients, both early hypoglycemia and early variability in BG are relatively common, and independently portend an increased risk for mortality.

Blood glucose control among critically ill patients with brain injury.

OBJECTIVE: To evaluate the incidence of hypoglycemia, hyperglycemia and blood glucose (BG) variability in brain-injured patients and their association with clinical outcomes. METHODS: Retrospective cohort study of brain-injured patients admitted to an 11-bed neurosciences intensive care unit (ICU) from January 1 to December 31, 2003. RESULTS: We included 606 patients. Mean age was 52.3 years, 60.6% were male, 11.9% had diabetes mellitus, and 64% were post-operative. Seventy-five (12.4%) received intensive insulin therapy (IIT) for a median (IQR) 72 (24-154) hours. Hypoglycemia and hyperglycemia occurred in 4.6% (96.4% receiving IIT) and 9.6% (77.6% receiving IIT). Median number of episodes per patient was 3 (75% with > or = 2) and 4 (81% with > or = 2) for hypoglycemia and hyperglycemia. Variable glycemic control occurred in 3.8% (100% receiving IIT) with median number of 13 episodes per patient. In-hospital mortality was 16.7%, median (IQR) ICU and hospital lengths of stay were 2 (1-5) and 8 (3-19) days. Hypoglycemia, hyperglycemia and BG variability showed non-significant but consistent associations with hospital mortality and prolonged lengths of ICU and hospital stay. The rate of recurrence of episodes showed stronger and significant associations with outcome, in particular for BG variability and hyperglycemia. CONCLUSIONS: Hypoglycemia, hyperglycemia and BG variability are relatively common in brain-injured patients and are associated with IIT. An increased frequency of episodes, in particular for BG variability and hyperglycemia, was associated with greater risk of both hospital death and prolonged duration of stay.

Severe head injury: clinicians' awareness of the literature.

OBJECTIVES: 1. To determine the awareness of the literature concerning therapeutic manoeuvres in severe closed head injury (CHI) among Canadian critical care clinicians and neurosurgeons, 2. To identify factors that affect utilization of these manoeuvres, and 3. To compare reported appropriateness and frequency of use with #1 and #2. METHODS: The study design was a systematic scenario-based survey of all neurosurgeons and critical care physicians treating patients with severe CHI in Canada. RESULTS: Fifty-nine of 99 neurosurgeons and 82 of 148 critical care physicians responded (57%). The majority of respondents were not able to identify the highest level of published evidence for most manoeuvres, except for the avoidance of corticosteroids (51%). The factor identified by most respondents as being most important in motivating use of any given manoeuvres was the level of published evidence (25%). Although reported appropriateness and frequency of use of most manoeuvres correlated well with each other, they did not correlate with awareness of evidence. In the case of corticosteroids, there was a strong correlation between non-use of steroids and awareness of evidence (R = -0.30, p = 0.0003). CONCLUSIONS: Respondents to this survey of Canadian physicians treating patients with severe head injury reported published evidence as being the most significant factor affecting use of a therapy. However, most respondents did not correctly identify the highest published level of evidence for most therapies. This study has identified difficulty with research translation that may have clinical implications.

Survey of management of severe head injury in Canada.

OBJECTIVE: To determine: 1. the degrees of consensus and disagreement among Canadian critical care clinicians regarding the appropriateness (benefit exceeding risk) of common therapeutic manoeuvres in patients with severe closed head injury (CHI), and 2. the frequency with which clinicians employed these manoeuvres. METHODS: The study design was a systematic scenario-based survey of all neurosurgeons and critical care physicians treating patients with severe CHI in Canada. RESULTS: In the scenario of acute epidural hematoma with mass effect, respondents agreed very strongly that surgery was appropriate. Clinicians reported mannitol and hypertonic saline as appropriate. Beyond these two interventions, agreement was less strong, and the use of the extraventricular drain (EVD), phenytoin, cooling, hyperventilation, nimodipine, and jugular venous oximetry (JVO) were of uncertain appropriateness. Steroids were considered inappropriate. In a scenario of diffuse axonal injury (DAI), clinicians agreed strongly that fever reduction, early enteral feeding, intensive glucose control, and cerebral perfusion pressure (CPP)-directed management were appropriate. The use of mannitol, hypertonic saline, EVD, JVO, narcotics and propofol were also appropriate. Neuromuscular blockade, surgery, and hyperventilation were of uncertain appropriateness. The appropriateness ratings of the interventions considered in the scenario of an intracranial contusion mirrored the DAI scenario. In general, correlations between the reported appropriateness and frequency of use of each intervention were very high. An exception noted was the use of the JVO. The correlation between CPP-guided therapy and the use of the EVD was weak. CONCLUSIONS: This survey has described current practice with regard to treatment of patients with severe CHI. Areas of variation in perceived appropriateness were identified that may benefit from further evaluation. Suggested priorities for evaluation include the use of osmotic diuretics, anticonvulsants, and intracranial manometry.

Methemoglobinemia after transesophageal echocardiography: a life-threatening complication.

Methemoglobinemia is an uncommon cause of tissue hypoxemia that can be life-threatening if not promptly identified and treated. It can occur after exposure to an oxidizing agent from contaminated well water or from nitroglycerin, sodium nitroprusside, or certain local anesthetics. During oropharyngeal use of topical anesthetics for transesophageal echocardiography, systemic drug uptake is unpredictable and unexplained complications can ensue. Treatment of acquired methemoglobinemia may require methylene blue, as oxygen is not usually sufficient. Avoidance of the oxidizing agent, probably benzocaine in the cases presented, is prudent.

Cohort study of intraventricular thrombolysis with recombinant tissue plasminogen activator for aneurysmal intraventricular hemorrhage.

OBJECTIVE: Thrombolytic agents have been administered through external ventricular drains to treat intraventricular hemorrhage, the goals being to accelerate clot clearance, prevent catheter obstruction, and help control intracranial pressure. We compared these variables in a group of aneurysm patients treated by one surgeon who routinely used intraventricular recombinant tissue plasminogen activator (rt-PA) for obstructive hematocephalus with those in a group of similar patients treated by other surgeons who did not. METHODS: Patients included in this analysis were those with repaired cerebral aneurysms causing hemorrhage into at least three ventricles with ventriculomegaly requiring external ventricular drainage. The ventricular system was considered "opened" when all ventricles were patent and reduced in size on computed tomographic scans. Those treated with rt-PA received 4 mg/d through a ventricular drain until ventricular opening. RESULTS: The mean number of days to ventricular opening was 3.9 (standard deviation [SD], 1.0) for the 21 patients treated with rt-PA and 7.1 (SD, 3.7) for the 9 who were not (P = 0.001), and the mean intracranial pressure (mm Hg) 24 hours after treatment with rt-PA was 10.4 (SD, 6.1) compared with 14.1 (SD, 5.9) during the same interval for the group that did not receive rt-PA (P = 0.13). Ventricular catheter replacement was required in 1 rt-PA patient (for a misplaced catheter, before rt-PA treatment) and 3 patients who did not receive rt-PA (all for catheter obstructions with blood clot) (P = 0.07), and ventriculoperitoneal shunts were placed in 4 rt-PA patients and 3 patients who did not receive rt-PA (P = 0.4). CONCLUSION: Intraventricular thrombolysis with rt-PA seems to assist in the acute management of patients with large aneurysmal intraventricular hemorrhages, speeding clearance of aneurysmal intraventricular hemorrhage, normalizing intracranial pressure, and reducing ventricular catheter obstruction. A randomized trial is needed to confirm these findings, establish treatment safety, and determine whether treatment affects outcome.