Medical-surgical Intensive Care Unit Patients Research Articles

Nociception assessment with videopupillometry in deeply sedated intensive care patients: Discriminative and criterion validations

BackgroundNociceptive assessment in deeply sedated patients is challenging. Validated instruments are lacking for this unresponsive population. Videopupillometry is a promising tool but has not been established in intensive care settings. Aim/ObjectiveTo test the discriminate validity of pupillary dilation reflex (PDR) between non-noxious and noxious procedures for assessing nociception in non-neurological intensive care unit (ICU) patients and to test the criterion validity of pupil dilation using recommended PDR cut-off points to determine nociception. MethodsA single-centre prospective observational study was conducted in medical–surgical ICU patients. Two independent investigators performed videopupillometer measurements during a non-noxious and a noxious procedure, once a day (up to 7 days), when the patient remained deeply sedated (Richmond Agitation–Sedation Scale score: −5 or −4). The non-noxious procedures consisted of a gentle touch on each shoulder and the noxious procedures were endotracheal suctioning or turning onto the side. Bivariable and multivariable general linear mixed models were used to account for multiple measurements in same patients. Sensitivity and specificity, and areas under the curve of the receiver operating characteristic curve were calculated. ResultsSixty patients were included, and 305 sets of 3 measurements (before, during, and after), were performed. PDR was higher during noxious procedures than before (mean difference between noxious and non-noxious procedures = 31.66%). After testing all variables of patient and stimulation characteristics in bivariable models, age and noxious procedures were kept in the multivariable model. Adjusting for age, noxious procedures (coefficient = −15.14 (95% confidence interval = −20.17 to −15.52, p < 0.001) remained the only predictive factor for higher pupil change. Testing recommended cut-offs, a PDR of >12% showed a sensitivity of 65%, and a specificity of 94% for nociception prediction, with an area under the receiver operating curve of 0.828 (95% confidence interval = 0.779–0.877). ConclusionsIn conclusion, PDR is a potentially appropriate measure to assess nociception in deeply sedated ICU patients, and we suggest considering its utility in daily practices. RegistrationThis study was not preregistered in a clinical registry. Tweetable abstractPupillometry may help clinicians to assess nociception in deeply sedated ICU patients.

Long-stay medical-surgical intensive care unit patients in South Africa: Quality of life and mortality 1 year after discharge

Background. Although mortality is the primary measure of critical care outcome, the health-related quality of life (HRQOL) of survivors is often diminished. There is a paucity of South African research on HRQOL in intensive care unit (ICU) survivors. Objectives. To evaluate the 1-year post-discharge data of long-stay ICU patients, a group known to consume 20 - 40% of ICU resources. Methods. A 1-year prospective observational study was conducted in a multidisciplinary medical-surgical ICU. Adult patients who were mechanically ventilated beyond 6 days were included. Clinical and mortality data were collected. Pre-admission and 6- and 12-month HRQOL were measured with the Short Form-36 questionnaire. Physical and mental component summary scores (PCS and MCS) were calculated. Associations between 12-month mortality and poor HRQOL scores were determined. Results. Of 119 patients enrolled, 40.3% had sustained trauma, 19.3% were post-surgical and 40.3% had medical conditions; 29.2% were HIV-positive (HIV status was known for 74.8% of the cohort). The hospital and 12-month mortality rates were 42.9% and 57.4% (n=66/115), respectively. Age, longer ICU stay, higher disease severity scores and vasopressor use were associated with 12-month mortality. The survivors’ median PCS and MCS at 6 and 12 months were significantly lower compared with pre-admission scores (both p&lt;0.001). At 12 months, 53.1% of survivors demonstrated a poor PCS and 42.9% a poor MCS. Associations with poor 12-month PCS included longer ICU stay, male gender and trauma, while trauma and sepsis were associated with a poor 12-month MCS. Among the 19 trauma survivors, 78.9% had a poor MCS and/or PCS. Of previously employed patients, 54.8% were unemployed at 12 months. Conclusions. Patients ventilated beyond 6 days in a multidisciplinary ICU had a high mortality. Poor HRQOL at 12 months post discharge was frequently observed among survivors. Trauma was associated with poor 12-month outcomes. These findings highlight the need to further explore the outcomes of long-stay ICU patients in Africa.

Usefulness of the Biomarker TIMP-2•IGFBP7 for Acute Kidney Injury Assessment in Critically Ill Patients: A Narrative Review.

To review the clinical usefulness of the biomarker TIMP-2•IGFBP7 in adult, general medical-surgical intensive care unit (ICU) settings. PubMed (1946 to mid-February 2021) and EMBASE (1947 to mid-February 2021) with bibliographies of retrieved articles reviewed for additional articles. Studies evaluating use of the urinary TIMP-2•IGFBP7 assay in adult patients in ICU settings. Studies published after investigations leading to TIMP-2•IGFBP7 assay approval confirm the appropriateness of considerations discussed in product labeling, such as use of the test within 12 hours of assessment, use of a dichotomous 0.3 (ng/mL)2/1000 cutoff, and use only in combination with other assessments of acute kidney injury (AKI). However, as a biomarker routinely used for early identification of patients at risk for AKI in mixed ICU populations, the additional resources required for TIMP-2•IGFBP monitoring are difficult to justify because of limited data demonstrating usefulness in preventing or ameliorating AKI and its attendant complications. Biomarkers are potentially useful not only for assessment and diagnosis of AKI, but also for practitioners involved in the management of nephrotoxic medications and medications needing adjustment for decreased kidney function. Although there is evidence to suggest that the urinary TIMP-2•IGFBP7 biomarker is helpful in predicting AKI progression in general medical-surgical ICU patients when used within 12 hours of patient assessment in combination with routine testing, including serum creatinine and urine output, there is little evidence that its use leads to improvements in clinically important patient outcomes.

Risk factors for peripherally inserted central catheter line-related deep venous thrombosis in critically ill intensive care unit patients.

Introduction:Central venous access using peripherally inserted central catheters is frequently used for patients receiving intravenous medications in the hospital or outpatients. Although there are several benefits of peripherally inserted central catheters, such as ease of insertion, low procedure-related risk and higher patient satisfaction, there are complications associated with peripherally inserted central catheter use. Despite some studies evaluating peripherally inserted central catheter line–related complications, the factors associated with peripherally inserted central catheter–related deep venous thrombosis in critically ill medical-surgical patients are poorly described. The objective of this case-control study was to identify the risk factors associated with peripherally inserted central catheter line–related deep venous thrombosis in critically ill medical-surgical intensive care unit patients in a community hospital.Methods:We abstracted relevant clinical data from 21 cases with symptomatic peripherally inserted central catheter–related deep venous thrombosis and 42 controls with peripherally inserted central catheters but no deep venous thrombosis.Results:Of the factors evaluated, female gender, the use of triple lumen peripherally inserted central catheters, larger outer diameter, and open (vs valve) peripherally inserted central catheters were associated with venous thrombosis. In this retrospective study, we did not identify any association of peripherally inserted central catheter–related deep venous thrombosis with a prior history of deep venous thrombosis, use of alteplase, antiplatelet therapy, prophylactic or therapeutic anticoagulation, international normalized ratio, platelet count and the use of peripherally inserted central catheters for total parenteral nutrition.Conclusion:Our study indicates that the catheter size relative to the diameter of the vein could be an important risk factor for the development of peripherally inserted central catheter–related deep venous thrombosis. The study findings should be confirmed in a larger study designed to identify risk factors of peripherally inserted central catheter–related deep venous thrombosis. In the meantime, the peripherally inserted central catheter lines should be used judiciously in critically ill patients.

Blood Loss Due to Laboratory Testing in Critical Care Patients: A Retrospective Cohort Study

Background: Anemia and red blood cell (RBC) transfusions occur frequently in intensive care unit (ICU) patients and are associated with morbidity and mortality. Observational data suggest that anemia (nadir hemoglobin ≤ 9 g/dL) in ICU patients is associated with an increased risk of death within 30 days (OR 1.54, 95% confidence interval [CI] 1.12-2.12). Although anemia in this population is likely multifactorial, phlebotomy for laboratory testing is substantial (up to 41 mL/day) and may be a modifiable contributor as only 10% of the blood collected is required for analysis. This study aims to (i) characterize the blood volume taken for laboratory testing in ICU patients, and (ii) explore the effect of blood taken for testing on rates of RBC transfusion and anemia in a contemporary cohort of ICU patients.Methods: We conducted a retrospective cohort study of consecutive adult patients, age ≥18 years, admitted to a medical-surgical ICU for ≥48 hours in Hamilton, Ontario between November 1, 2012 to October 1, 2015. We extracted data from previously validated administrative databases. The primary outcome was estimated volume of blood drawn for laboratory testing during index ICU admission calculated using the number of unique blood specimens drawn and known sampling tube volumes. Secondary outcomes included: incidence of severe anemia (hemoglobin ≤9 g/dL), discharge hemoglobin adjusted for RBC transfusion (1.0 g/dL subtracted for each RBC transfusion administered), proportion of patients receiving RBC transfusion, number of RBC units transfused per patient, duration of ICU admission and ICU mortality. Categorical data are reported as counts and proportions. Continuous data are reported as means with standard deviations (SD) or medians with interquartile range (IQR). Predictors of RBC transfusion were examined using Cox regression analysis. P-values <0.05 were considered statistically significant.Results: We included 7,273 ICU patients. The median age was 66 years (IQR 54-76 years) and 40.8% of patients were female. Most responsible diagnosis was circulatory (33.3%), followed by injury/poisoning (15.9%), respiratory (12.8%), and gastrointestinal (9.2%). The ICU mortality rate was 13.8% and the median ICU length of stay was 5 days (IQR 3-10 days). On ICU admission, median hemoglobin value was 9.7 g/dL (IQR 8.2-11.6 g/dL) and 39.6% of patients had hemoglobin ≤ 9.0 g/dL.Median blood loss due to laboratory testing was 25 mL per patient per day (IQR 14-43 mL) and 213 mL per patient for the ICU admission (IQR 133-382 mL). On ICU discharge, median hemoglobin was 8.4 g/dL (IQR 5.8-10.5 g/dL), and 67.0% of patients had hemoglobin ≤ 9.0 g/dL while in ICU. After adjusting for RBC transfusions, the median decrease in hemoglobin from ICU admission to discharge was 1.2 g/dL (IQR 0-2.9 g/dL). RBC transfusions were administered to 47.5% of patients while in the ICU with 37.3% of these patients receiving 5 or more units. The median number of RBC units received in transfused patients was 3 (IQR 2-7). Additional blood drawn for laboratory testing of 150 mL from day 2 to day 7 of ICU admission (hazard ratio [HR] 2.3, 95%CI 2.1-2.5), hematologic diagnosis vs. other (HR 1.5, 95%CI 1.2-2.0), and RBC transfusion prior to ICU admission vs. none (HR 1.5, 95%CI 1.2-1.9) were associated with a higher risk of RBC transfusion in the ICU.Conclusions: Anemia and RBC transfusions are frequent in ICU patients with two-thirds of patients developing severe anemia (hemoglobin <9.0 g/dL) and 47.5% receiving RBC transfusion, respectively. Our results suggest that blood loss for laboratory testing remains substantial in contemporary medical-surgical ICU patients and is associated with the need for RBC transfusion. Strategies to reduce blood loss from laboratory testing represent an area for further prospective investigation. DisclosuresSiegal:BMS-Pfizer: Honoraria; Bayer: Honoraria; Portola Pharmaceuticals: Honoraria.

Accuracy, reliability, feasibility and nurse acceptance of a subcutaneous continuous glucose management system in critically ill patients: a prospective clinical trial.

BackgroundContinuous glucose monitoring (CGM) has not yet been implemented in the intensive care unit (ICU) setting. The purpose of this study was to evaluate reliability, feasibility, nurse acceptance and accuracy of the Medtronic Sentrino® CGM system in critically ill patients.Methods Sensors were inserted into the subcutaneous tissue of the patient’s thigh, quantifying interstitial glucose concentration for up to 72 h per sensor. Reliability and feasibility analysis included frequency of data display, data gaps and reasons for sensor removal. We surveyed nurse acceptance in a questionnaire. For the accuracy analysis, we compared sensor values to glucose values obtained via blood gas analysis. Potential benefits of CGM were investigated in intra-individual analyses of factors, such as glycemic variability or time in target range achieved with CGM compared to that achieved with intermittent glucose monitoring.ResultsThe device generated 68,655 real-time values from 31 sensors in 20 critically ill patients. 532 comparative blood glucose values were collected. Data were displayed during 32.5 h [16.0/62.4] per sensor, which is 45.1 % of the expected time of 72 h and 84.8 % of 37.9 h actual monitoring time. 21 out of 31 sensors were removed prematurely. 79.1 % of the nursing staff rated the device as not beneficial; the response rate was one-third. Mean absolute relative difference was 15.3 % (CI 13.5–17.0 %). Clarke error grid: 76.9 % zone A, 21.6 % zone B, 0.2 % zone C, 0.9 % zone D, 0.4 % zone E. Bland–Altman plot: mean bias +0.53 mg/dl, limits of agreement +64.6 and −63.5 mg/dl. Accuracy deteriorated during elevated glycemic variability and in the hyperglycemic range. There was no reduction in dysglycemic events during CGM compared to 72 h before and after CGM. If CGM was measuring accurately, it identified more hyperglycemic events when compared to intermittent measurements. This study was not designed to evaluate potential benefits of CGM on glucose control.ConclusionsThe subcutaneous CGM system did not perform with satisfactory accuracy, feasibility, or nursing acceptance when evaluated in 20 medical-surgical ICU patients. Low point accuracy and prolonged data gaps significantly limited the potential clinical usefulness of the CGM trend data. Accurate continuous data display, with a MARD < 14 %, showed potential benefits in a subgroup of our patients.Trial registration NCT02296372; Ethic vote Charité EA2/095/14Electronic supplementary materialThe online version of this article (doi:10.1186/s13613-016-0167-z) contains supplementary material, which is available to authorized users.

Heparin-induced thrombocytopenia in the critically ill: Interpreting the 4Ts test in a randomized trial

BackgroundThrombocytopenia occurs in 20% to 45% of critically ill medical-surgical patients. The 4Ts heparin-induced thrombocytopenia (HIT) score (with 4 domains: Thrombocytopenia, Timing of thrombocytopenia, Thrombosis and oTher reason[s] for thrombocytopenia) might reliably identify patients at low risk for HIT. Interobserver agreement on 4Ts scoring is uncertain in this setting. ObjectiveTo evaluate whether a published clinical prediction rule (the “4Ts score”) reliably rules out HIT in “low-risk” intensive care unit (ICU) patients as assessed by research coordinators (who prospectively scored) and 2 adjudicators (who scored retrospectively) during an international heparin thromboprophylaxis trial (PROTECT, NCT00182143). MethodsOf 3746 medical-surgical ICU patients in PROTECT, 794 met the enrollment criteria for this HIT substudy. Enrollment was predicated on one of the following occurring in ICU: platelets less than 50 × 109/L, platelets decreased to 50% of ICU admission value (if admission value <100 × 109/L), any venous thrombosis, or if HIT was otherwise clinically suspected. Independently, 4Ts scores were completed in real time by research coordinators blinded to study drug and laboratory HIT results, and retrospectively by 2 adjudicators blinded to study drug, laboratory HIT results, and research coordinators' scores; the adjudicators arrived at consensus in all cases. Of the 763 patients, 474 had a central or local laboratory HIT test performed and had 4Ts scoring by adjudicators; 432 were scored by trained research coordinators. Heparin-induced thrombocytopenia was defined by a centrally performed positive serotonin release assay (SRA). ResultsOf the 474 patients with central adjudication, 407 (85.9%) had a 4Ts score of 3 or lower, conferring a low pretest probability (PTP) of HIT; of these, 6 (1.5% [95% confidence interval, 0.7%-3.2%) had a positive SRA. Fifty-nine (12.4%) had a moderate PTP (4Ts score of 4-5); of these, 4 (6.8%) had a positive SRA. Eight patients had a high PTP (4Ts score of ≥6); of these, 1 (12.5%) had a positive SRA. Raw agreement between research coordinators and central adjudication on each domain of the 4Ts score and low, intermediate, and high PTP was good. However, chance-corrected agreement was variable between adjudicators (weighted κ values of 0.31-0.93) and between the adjudicator consensus and research coordinators (weighted κ values of 0.13 and 0.78). Post hoc review of the 6 SRA-positive cases with an adjudicated low PTP demonstrated that their scores would have been increased if the adjudicators had had additional information on heparin exposure prior to ICU admission. In general, the fourth domain of 4Ts (oTher causes of thrombocytopenia) generated the most disagreement. ConclusionsReal-time 4Ts scoring by research coordinators at the time of testing for HIT was not consistent with 4Ts scores obtained by central adjudicators. The results of this comprehensive HIT testing highlight the need for further research to improve the assessment of PTP scoring of HIT for critically ill patients.

Barriers and facilitators of thromboprophylaxis for medical-surgical intensive care unit patients: A multicenter survey

BackgroundThe objective of this study was to identify the self-reported barriers to and facilitators of prescribing low-molecular-weight heparin (LMWH) thromboprophylaxis in the intensive care unit (ICU). MethodsWe conducted an interviewer-administered survey of 4 individuals per ICU (the ICU director, a bedside pharmacist, a thromboprophylaxis research coordinator, and physician site investigator) regarding LMWH thromboprophylaxis for medical-surgical patients in 27 ICUs in Canada and the United States. Items were generated by the research team and adapted from previous surveys, audits, qualitative studies, and quality improvement research. Respondents rated the barriers to LMWH use, facilitators (effectiveness, affordability, and acceptability thereof), and perceptions regarding LMWH use. ResultsRespondents had 14.5 (SD, 7.7) years of ICU experience (response rate, 99%). The 5 most common barriers in descending order were as follows: drug acquisition cost, fear of bleeding, lack of resident education, concern about bioaccumulation in renal failure, and habit. The top 5 rated facilitators were preprinted orders, education, daily reminders, audit and feedback, and local quality improvement committee endorsement. Centers using preprinted orders (mean difference [P<.01]) and computerized physician order entry (P<.01) compared with those centers not using those tools reported higher affordability for these 2 facilitators. Compared with physicians and pharmacists, research coordinators considered ICU-specific audit and feedback of thromboprophylaxis rates to be a more effective, acceptable, and affordable facilitator (odds ratio, 6.67; 95% confidence interval, 1.97-22.53; P<.01). Facilitator acceptability ratings were similar within centers but differed across centers (P≤.01). ConclusionsThis multicenter survey found several barriers to use of LMWH including cost, concern about bleeding, and lack of resident knowledge of effectiveness. The diversity of reported facilitators suggests that large scale programs may address generic barriers but also need site-specific interprofessional knowledge translation activities.

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Introduction: Delirium in the intensive care unit (ICU) is associated with increased mortality and poor outcomes. The Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) is a validated screening tool used to assess delirium. Limited data exist regarding optimal pharmacologic and non-pharmacologic prevention and management of delirium. This study sought to evaluate the impact of a pharmacist-led intervention on delirium assessment and management. Methods: Prospective chart review of adult medical-surgical (MSICU) and cardiac (CICU) ICU patients was conducted for one week before and after pharmacist intervention. Delirium screens were evaluated daily by ICU pharmacists who recommended non-pharmacologic and pharmacologic delirium management strategies. The primary objective was to analyze compliance rates with CAM-ICU assessments and patient delirium status. Secondary objectives included use of non-pharmacologic interventions, avoidance of delirium-precipitating medications, and antipsychotic prescribing patterns. Categorical data were analyzed with the Chi squared test or Fisher's exact test, as appropriate. Results: A total of 534 and 514 nursing shifts were evaluated pre- and post-intervention, respectively. Rates of attempted CAM-ICU assessments increased post-intervention (62% v 70%, p=0.005), with similar numbers of positive screens (6.7% v 9.9%). Deliriogenic medication exposure was reduced post-intervention in the MSICU (71% v 44%, p<0.001) but not the CICU (53% v 51%, p=0.71). Similarly, antipsychotic use decreased in the MSICU (12% v 4%, p <0.001) but not the CICU. Conclusions: A pharmacist-led delirium initiative resulted in more attempted CAM-ICU screenings, reduced deliriogenic medication exposure, and reduced antipsychotic use among ICU patients. Patients not screened for delirium may represent unrecognized delirious patients and preclude assessment of the true intervention impact. Subsequent implementation of a multidisciplinary delirium prevention and management bundle may exhibit further improvement in delirium screening and management.

Current prevention practice for venous thromboembolism in Japanese intensive care units

Venous thromboembolism (VTE) is a well-recognized life-threatening complication in the intensive care unit (ICU). However, no data have been reported regarding the prevalence and methods of prevention of VTE in Japanese ICUs. This study aimed to document the current practice of VTE prevention across a broad sample of medical-surgical ICU patients in Japan. In November 2010, we performed a point-prevalence survey of Japanese ICUs in training facilities for intensive care specialists. We recorded data from five consecutive ICU patients in each facility at any time on the day of the survey. A total of 470 patients were registered in this study. VTE prophylaxis was received by 85.3 % of participants. Of these, 69.8 % received mechanical prophylaxis and 12.5 % received pharmacological methods, with 17.7 % receiving both methods. Analyzing a comparison of the presence or absence of a hospital prevention protocol, the protocol group had higher rates of receiving prophylaxis (88.8 % vs. 80.0 %, P < 0.01) than the no-protocol group. In conclusion, VTE prophylaxis by mechanical methods was the main method in a high number of medical-surgical ICU patients in Japan. The ICUs with a hospital VTE prevention protocol in place performed significantly higher rates of prophylaxis than those without a protocol.

A double-blind, randomized clinical trial comparing soybean oil–based versus olive oil–based lipid emulsions in adult medical–surgical intensive care unit patients requiring parenteral nutrition*

Parenteral nutrition has been associated with metabolic and infectious complications in intensive care unit patients. The underlying mechanism for the high risk of complications is not known but may relate to the proinflammatory effects of soybean oil-based lipid emulsions, the only Food and Drug Administration-approved lipid formulation for clinical use. Prospective, double-blind, randomized, controlled trial. Medical-surgical intensive care units from a major urban teaching hospital and a tertiary referral university hospital. Adult medical-surgical intensive care unit patients. Parenteral nutrition containing soybean oil-based (Intralipid) or olive oil-based (ClinOleic) lipid emulsions. Differences in hospital clinical outcomes (nosocomial infections and noninfectious complications), hospital length of stay, glycemic control, inflammatory and oxidative stress markers, and granulocyte and monocyte functions between study groups. A total of 100 patients were randomized to either soybean oil-based parenteral nutrition or olive oil-based parenteral nutrition for up to 28 days. A total of 49 patients received soybean oil-based parenteral nutrition (age 51 ± 15 yrs, body mass index 27 ± 6 kg/m2, and Acute Physiology and Chronic Health Evaluation II score 15.5 ± 7 [±SD]), and a total of 51 patients received olive oil-based lipid emulsion in parenteral nutrition (age 46 ± 19 yrs, body mass index 27 ± 8 kg/m2, and Acute Physiology and Chronic Health Evaluation II score 15.1 ± 6 [±SD]) for a mean duration of 12.9 ± 8 days. The mean hospital blood glucose concentration during parenteral nutrition was 129 ± 14 mg/dL, without differences between groups. Patients treated with soybean oil-based and olive oil-based parenteral nutrition had a similar length of stay (47 ± 47 days and 41 ± 36 days, p = .49), mortality (16.3% and 9.8%, p = .38), nosocomial infections (43% vs. 57%, p = .16), and acute renal failure (26% vs. 18%, p = .34). In addition, there were no differences in inflammatory and oxidative stress markers or in granulocyte and monocyte functions between groups. The administration of parenteral nutrition containing soybean oil-based and olive oil-based lipid emulsion resulted in similar rates of infectious and noninfectious complications and no differences in glycemic control, inflammatory and oxidative stress markers, and immune function in critically ill adults.

Responsiveness of the frontal EMG for monitoring the sedation state of critically ill patients

Excessive sedation is associated with adverse patient outcomes during critical illness, and a validated monitoring technology could improve care. We developed a novel method, the responsiveness index (RI) of the frontal EMG. We compared RI data with Ramsay clinical sedation assessments in general and cardiac intensive care unit (ICU) patients. We developed the algorithm by iterative analysis of detailed observational data in 30 medical-surgical ICU patients and described its performance in this cohort and 15 patients recovering from scheduled cardiac surgery. Continuous EMG data were collected via frontal electrodes and RI data compared with modified Ramsay sedation state assessments recorded regularly by a blinded trained observer. RI performance was compared with Entropy™ across Ramsay categories to assess validity. RI correlated well with the Ramsay category, especially for the cardiac surgery cohort (general ICU patients ρ=0.55; cardiac surgery patients ρ=0.85, both P<0.0001). Discrimination across all Ramsay categories was reasonable in the general ICU patient cohort [P(K)=0.74 (sem 0.02)] and excellent in the cardiac surgery cohort [P(K)=0.92 (0.02)]. Discrimination between 'lighter' vs 'deeper' (Ramsay 1-3 vs 4-6) was good for general ICU patients [P(K)=0.80 (0.02)] and excellent for cardiac surgery patients [P(K)=0.96 (0.02)]. Performance was significantly better than Entropy™. Examination of individual cases suggested good face validity. RI of the frontal EMG has promise as a continuous sedation state monitor in critically ill patients. Further investigation to determine its utility in ICU decision-making is warranted.

Screening and Prevention of Venous Thromboembolism in Critically Ill Patients

Venous thromboembolism is difficult to diagnose in critically ill patients and may increase morbidity and mortality. To evaluate the cost-effectiveness of strategies to reduce morbidity from venous thromboembolism in critically ill patients. A Markov decision analytic model to compare weekly compression ultrasound screening (screening) plus investigation for clinically suspected deep vein thrombosis (DVT) (case finding) versus case finding alone; and a hypothetical program to increase adherence to DVT prevention. Probabilities were derived from a systematic review of venous thromboembolism in medical-surgical intensive care unit patients. Costs (in 2010 $US) were obtained from hospitals in Canada, Australia, and the United States, and the medical literature. Analyses were conducted from a societal perspective over a lifetime horizon. Outcomes included costs, quality-adjusted life-years (QALY), and incremental cost-effectiveness ratios. In the base case, the rate of proximal DVT was 85 per 1,000 patients. Screening resulted in three fewer pulmonary emboli than case-finding alone but also two additional bleeding episodes, and cost $223,801 per QALY gained. In sensitivity analyses, screening cost less than $50,000 per QALY only if the probability of proximal DVT increased from a baseline of 8.5-16%. By comparison, increasing adherence to appropriate pharmacologic thromboprophylaxis by 10% resulted in 16 fewer DVTs, one fewer pulmonary emboli, and one additional heparin-induced thrombocytopenia and bleeding event, and cost $27,953 per QALY gained. Programs achieving increased adherence to best-practice venous thromboembolism prevention were cost-effective over a wide range of program costs and were robust in probabilistic sensitivity analyses. Appropriate prophylaxis provides better value in terms of costs and health gains than routine screening for DVT. Resources should be targeted at optimizing thromboprophylaxis.

Diagnostic Accuracy of Computed Tomography Imaging of Surgically Treated Acute Acalculous Cholecystitis in Critically Ill Patients

Acute acalculous cholecystitis (AAC) is a potentially fatal condition mainly affecting critically ill patients. Current experience from computed tomography (CT) findings in AAC is contradictory. CT images of 127 mixed medical-surgical intensive care unit patients were retrospectively reviewed for the following findings: bile density, thickness and enhancement of the gallbladder (GB) wall, subserosal edema, greatest perpendicular diameters of the GB, width of extrahepatic bile ducts, gas within the GB, ascites, peritoneal fat edema, and diffuse tissue edema. Forty-three of these patients underwent open cholecystectomy, and 8 patients revealed a normal GB, 26 an edematous GB, and 9 a necrotic AAC. Abnormal CT findings were present in 96% of all the intensive care unit patients. Higher bile density in the GB body and subserosal edema was associated with an edematous GB (specificity, 93.6%; sensitivity, 23.1%). The most specific findings predicting necrotic AAC were gas in the GB wall or lumen, lack of GB wall enhancement, and edema around the GB (specificity, 99.2%, 94.9%, and 92.4%, respectively; and sensitivity, 11.1%, 37.5%, and 22.2%, respectively). The frequency of nonspecific abnormal findings in the GB of critically ill patients limits the diagnostic value of CT scanning in detecting AAC. However, in the case of totally normal GB findings in CT, the probability of necrotic AAC is low.

The 4Ts scoring system for heparin-induced thrombocytopenia in medical-surgical intensive care unit patients

Background Heparin-induced thrombocytopenia (HIT) is commonly considered but rarely confirmed in critically ill patients. The 4Ts score ( Thrombocytopenia, Timing of thrombocytopenia, Thrombosis, and o Ther reason) might identify individual patients at risk of having this disorder. Objective The aim of the study was to evaluate the value of the 4Ts HIT score in comparison with the serotonin-release assay (SRA) in critically ill patients. Methods This study describes the combined results of 3 prospective studies enrolling critically ill patients who were investigated for HIT if platelets fell to less than 50 × 10 9/L or if platelet counts decreased to less than 50% of the value upon intensive care unit admission. We confirmed HIT by a positive platelet SRA. We assigned a 4Ts score blinded to SRA results to all 50 patients investigated for HIT; those with positive SRA results were scored in duplicate. Results Of 528 patients, 50 (9.5%) were investigated for HIT; 39 (78%) of 50 (64%-88%) of these patients were scored as “low probability” by 4Ts score and none had a positive SRA. Of 49 patients who underwent SRA testing because of thrombocytopenia, only 2 (4.1%; 0.5-14.0) had a positive SRA (1 with a moderate 4Ts score and 1 with a high 4Ts score). Therefore, the overall incidence of HIT confirmed by SRA was 2 (0.4%) of 528 (0.04%-1.4%). Conclusions Significant thrombocytopenia during heparin administration occurred in 9.5% of critically ill patients, but HIT was confirmed in only 4.1% of those undergoing testing, for an overall incidence of 0.4%. A low 4Ts score occurred in 78% of patients investigated for HIT; none of these patients had a positive SRA. We conclude that HIT is uncommon in critically ill patients and that the 4Ts score is worthy of further evaluation in this patient population.

Thromboprophylaxis in the intensive care unit: Focus on medical–surgical patients

Critically ill patients in the medical-surgical intensive care unit are at high risk for deep venous thrombosis and pulmonary embolism, which comprise venous thromboembolism. Herein, we describe the prevalence, incidence, risk factors, clinical consequences, prophylaxis against venous thromboembolism in critically ill patients, and compliance with thromboprophylaxis. We focus primarily on medical-surgical intensive care unit patients, who represent the largest subgroup of critically ill patients. Despite the large and growing number of critically ill patients in our aging society, their high risk for venous thromboembolism, and the morbidity and mortality associated with this complication of critical illness, relatively few rigorous studies are available. Large, well-designed, randomized trials of thromboprophylaxis, powered to detect differences in patient-important outcomes, are required to advance our understanding and care of these vulnerable patients. Furthermore, because thromboprophylaxis is a common error of omission in hospitalized patients, redoubled efforts are needed to ensure that it is used in practice.

Perioperative Blood Glucose Monitoring and Control in Major Vascular Surgery Patients

Diabetes mellitus (DM) is an independent predictor for morbidity and mortality in the general population, which is even more apparent in patients with concomitant cardiovascular risk factors. As the prevalence of DM is increasing, with an ageing general population, it is expected that the number of diabetic patients requiring surgical interventions will increase. Perioperative hyperglycaemia, without known DM, has been identified as a predictor for morbidity and mortality in patients undergoing surgery. Moreover, early studies showed that intensive blood-glucose-lowering therapy reduced both morbidity and mortality among patients admitted to the postoperative intensive care unit (ICU). However, later studies have doubted the benefit of intensive glucose control in medical–surgical ICU patients. This article aims to comprehensively review the evidence on the use of perioperative intensive glucose control, and to provide recommendations for current clinical practice. A systematic review was performed of the literature on perioperative intensive glucose control. Based on this literature review, we observed that intensive glucose control in the perioperative period has no clear benefit on short-term mortality. Intensive glucose control may even have a net harmful effect in selected patients. In addition, concerns on the external validity of some studies are important barriers for widespread recommendation of intensive glucose control in the perioperative setting. We propose that guidelines recommending intensive glucose control should be re-evaluated. In addition, moderate tight glucose control should currently be regarded as the safest and most efficient approach to patients undergoing major vascular surgery.

JOE DOUPE LECTURE: Cardiac troponin in the intensive care unit

Cardiac troponin is specific to the myocardium and is a useful biomarker for the diagnosis of myocardial infarction. Detection of elevated blood levels of troponin indicates damage to myocardial cells, but does not indicate the mechanism. Causes other than acute coronary syndromes and myocardial infarction can result in troponin elevation and these conditions frequently occur in critically ill patients in the intensive care unit. The interpretation, clinical significance and appropriate management of an elevated troponin measurement in critically ill patients are uncertain. Studies evaluating the prevalence of troponin elevation among medical-surgical intensive care unit patients, and its prognostic significance with regards to adverse outcomes will be reviewed. Cardiac troponin elevation is common and observed in 40 to 50% of critically ill medical and surgical patients. Elevated levels appear to identify patients at increased risk for death in the intensive care unit or hospital setting. This finding, and its relation to myocardial infarction and acute coronary syndromes, requires prospective study to better understand the implications for diagnosis and management.

Hypoglycemia with intensive insulin therapy in critically ill patients: Predisposing factors and association with mortality*

: To examine the predisposing factors for hypoglycemia in medical-surgical intensive care unit patients treated with intensive insulin therapy and to assess its association with mortality. : Nested-cohort study within a randomized controlled trial. : Tertiary care intensive care unit. : Medical-surgical intensive care unit patients with admission blood glucose of >6.1 mmol/L or 110 mg/dL who were enrolled in a randomized controlled trial comparing intensive insulin therapy with conventional insulin therapy. : None. : Hypoglycemia was defined as blood glucose < or =2.2 mmol/L or 40 mg/dL and intensive care unit mortality was the primary outcome. : Among the 523 patients included in the study, hypoglycemia occurred in 84 (16%). Intensive insulin therapy was independently associated with increased risk of hypoglycemia (adjusted odds ratio, 50.65; 95% confidence interval, 17.36-147.78; p < .0001). Other variables associated with an increased risk of hypoglycemia included female gender, diabetes, Acute Physiology and Chronic Health Evaluation II, mechanical ventilation, continuous veno-venous hemodialysis, and intensive care unit length of stay. When adjusted to potential confounders, hypoglycemia was not significantly associated with increased mortality (adjusted hazard ratio, 1.31; 95% confidence interval, .70-2.46; p = .40). Patients with admission blood glucose of < or =10 mmol/L had an increased mortality with hypoglycemia (adjusted hazard ratio, 4.43; 95% confidence interval, 1.36-14.44; p = .01). Crude analysis showed significant association of mortality with blood glucose levels of < or =1.2 mmol/L (adjusted hazard ratio, 2.92; 95% confidence interval, 1.05-8.11; p = .04). When adjusted analysis was performed, similar trend was seen but was not statistically significant (adjusted hazard ratio, 2.56; 95% confidence interval, .85-7.70; p = .10). : Our study showed significant increase of hypoglycemia with intensive insulin therapy. Although hypoglycemia was not independently associated with increased risk of death, increased mortality could not be excluded with severe hypoglycemia and in patients admitted with blood glucose of < or =10 mmol/L.

Perioperative Blood Glucose Monitoring and Control in Major Vascular Surgery Patients

Diabetes mellitus (DM) is an independent predictor for morbidity and mortality in the general population, which is even more apparent in patients with concomitant cardiovascular risk factors. As the prevalence of DM is increasing, with an ageing general population, it is expected that the number of diabetic patients requiring surgical interventions will increase. Perioperative hyperglycaemia, without known DM, has been identified as a predictor for morbidity and mortality in patients undergoing surgery. Moreover, early studies showed that intensive blood-glucose-lowering therapy reduced both morbidity and mortality among patients admitted to the postoperative intensive care unit (ICU). However, later studies have doubted the benefit of intensive glucose control in medical-surgical ICU patients. This article aims to comprehensively review the evidence on the use of perioperative intensive glucose control, and to provide recommendations for current clinical practice. A systematic review was performed of the literature on perioperative intensive glucose control. Based on this literature review, we observed that intensive glucose control in the perioperative period has no clear benefit on short-term mortality. Intensive glucose control may even have a net harmful effect in selected patients. In addition, concerns on the external validity of some studies are important barriers for widespread recommendation of intensive glucose control in the perioperative setting. We propose that guidelines recommending intensive glucose control should be re-evaluated. In addition, moderate tight glucose control should currently be regarded as the safest and most efficient approach to patients undergoing major vascular surgery.