Noncardiac Intensive Care Unit Research Articles

PKM2-dependent glycolysis promotes NLRP3 and AIM2 inflammasome activation

Sepsis, severe sepsis and septic shock are the main cause of mortality in non-cardiac intensive care units. Immunometabolism has been linked to sepsis; however, the precise mechanism by which metabolic reprogramming regulates the inflammatory response is unclear. Here we show that aerobic glycolysis contributes to sepsis by modulating inflammasome activation in macrophages. PKM2-mediated glycolysis promotes inflammasome activation by modulating EIF2AK2 phosphorylation in macrophages. Pharmacological and genetic inhibition of PKM2 or EIF2AK2 attenuates NLRP3 and AIM2 inflammasomes activation, and consequently suppresses the release of IL-1β, IL-18 and HMGB1 by macrophages. Pharmacological inhibition of the PKM2–EIF2AK2 pathway protects mice from lethal endotoxemia and polymicrobial sepsis. Moreover, conditional knockout of PKM2 in myeloid cells protects mice from septic death induced by NLRP3 and AIM2 inflammasome activation. These findings define an important role of PKM2 in immunometabolism and guide future development of therapeutic strategies to treat sepsis.

Comparison of Sepsis Screening Tools' Ability to Detect Sepsis Accurately.

Sepsis is the primary cause of perioperative mortality among general surgery patients and is the leading cause of death in non-cardiac intensive care units. To address this issue, the Surviving Sepsis Campaign Guidelines advocate for sepsis screening. However, there is little information in the current medical literature to suggest which sepsis screening tool is optimal. The purpose of this study was to compare a sepsis screening tool that we have validated and published previously, the Sepsis Screening Score (SSS), with a commercially available sepsis screening tool, the St. John's Sepsis Agent (SJSA) developed by Cerner (Kansas City, MO). This prospective observational study compares the accuracy of the SSS with that of the SJSA in the same patient population. The SSS was performed on each patient in our surgical intermediate care unit (SIMU) twice daily. The SJSA monitored these same patients continuously via the electronic medical record (EMR). Epidemiologic data related to sepsis were collected prospectively, and the performance characteristics of the two tests were compared using the two-sample test of proportions. A total of 348 patients were included in the study, and 47 (13.5%) of these patients developed sepsis. The SJSA was determined to have a sensitivity of 44.7%, a specificity of 84.7%, a positive predictive value (PPV) of 31.3%, and a negative predictive value (NPV) of 90.7%, while the SSS was determined to have a sensitivity of 74.5%, a specificity of 86.4%, a PPV of 46.1%, and an NPV of 95.6%. The differences in sensitivity (p < 0.001), PPV (p < 0.001), and NPV (p = 0.011) were found to be statistically significant. Despite the fact that SJSA had constant surveillance over patients' EMRs, it still detected fewer septic patients than the SSS, which was performed twice per day. The difference in sensitivities and NPVs between the two tests is of particular importance, because this indicates that the SSS is more effective in identifying patients with sepsis. This study establishes a basis for the utilization of the SSS instead of the SJSA.

Patients with sepsis

Sepsis is still the leading cause of mortality in noncardiac intensive care units. The new definition of sepsis emphasizes the importance of organ dysfunction. The Sepsis-related Organ Failure Assessment (SOFA) score is an indicator for organ dysfunction. The diagnosis of sepsis is for the most part made on clinical parameters with an altered mental status being a very sensitive indicator. Microbiological work-up is essential and two sets of blood cultures are the recommended minimum. Management includes prompt initiation of adequate antibiotic treatment and swift fluid resuscitation. Overinfusion is to be avoided as this itself can have a negative impact on patient outcome.

Risk Factors for Dexmedetomidine-Associated Hemodynamic Instability in Noncardiac Intensive Care Unit Patients.

The reported incidence of hypotension and bradycardia in patients receiving dexmedetomidine for sedation commonly exceeds 50%. In this study, we describe the incidence of, patient- and treatment-specific risk factors for, and clinical significance of dexmedetomidine-associated hemodynamic instability. This retrospective cohort study was conducted in critically ill adults receiving dexmedetomidine for sedation at Mayo Clinic Hospital in Rochester, MN, during a 1-year period. The primary end point was hemodynamic instability: a composite of hypotension and/or bradycardia, defined as systolic blood pressure <80 mm Hg, diastolic blood pressure <50 mm Hg, or heart rate <50 beats per minute during dexmedetomidine therapy. Cox proportional hazards models were constructed to determine hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk factors of hemodynamic instability. Hemodynamic instability occurred in 197 of the analyzed 300 patients receiving dexmedetomidine, resulting in a cumulative incidence of 71% at 24 hours via Kaplan-Meier estimation. In addition to dexmedetomidine, univariate analysis identified age, vasopressor use, low baseline arterial blood pressure, and concomitant sedatives as associated with increased risk of hemodynamic instability. Multivariable analysis demonstrated associations between age (HR, 1.23 per 10 years, 95% CI, 1.10-1.38) and low baseline blood pressure (HR, 2.42 at dexmedetomidine initiation, 95% CI, 1.68-3.49) and risk of hemodynamic instability. Variables such as concomitantly administered cardiac medications or sedative therapies and dexmedetomidine infusion rates >0.7 μg/kg/h were not found to be predictors of hemodynamic instability among the analyzed sample. Hemodynamic instability commonly occurs in critically ill adults receiving dexmedetomidine, with more than two thirds of this cohort experiencing hypotension and/or bradycardia within 24 hours of initiation. Increasing age and low baseline arterial blood pressure were associated with the development of hemodynamic instability. These findings suggest that clinicians should be aware of the potential risk of hemodynamic instability when using dexmedetomidine in patients with advanced age or low baseline arterial blood pressure.

ST2 Predicts Mortality and Length of Stay in a Critically Ill Noncardiac Intensive Care Unit Population.

The biomarker suppression of tumorigenicity 2 (ST2) is a well-established clinical biomarker of cardiac strain and is frequently elevated in a variety of cardiac conditions. Here, we sought to evaluate the prognostic value of ST2 in critically ill medical intensive care unit (MICU) patients without primary cardiac illness. We measured ST2 and high-sensitivity troponin T (hsTnT) on plasma specimens collected on 441 patients following admission to a noncardiac MICU and evaluated the prognostic power of ST2 both alone and in multivariate models. Of these critically ill patients, 96% exhibited ST2 concentrations above the reference interval. ST2 concentrations were highly predictive of intensive care unit and hospital length of stay, as well as in-hospital mortality, with high concentrations predicting a poor prognosis. Rates of in-hospital mortality were more than four times higher in patients with ST2 concentrations in the highest compared with the lowest quartile. In multivariate analysis, ST2 remained an important predictor of death after adjustment for age, hsTnT, and common diagnoses. ST2 is increased and predictive of prognosis in critically ill patients without primary cardiac disease, suggesting that critically ill patients may often have unrecognized cardiac injury. Clinical decision support algorithms incorporating ST2 and hsTnT results may be useful in patient risk stratification.

Impact of Infectious Diseases Team Consultation on Antimicrobial Use, Length of Stay and Mortality

Infectious disease (ID) clinicians and multidisciplinary teams may have a beneficial impact on patient outcomes. This study was conducted to determine the impact of dedicated ID team rounding in an adult noncardiac intensive care unit (ICU) on antimicrobial costs, length of stay and mortality. The authors instituted dedicated ICU ID team rounds at a large tertiary care hospital ICU ("intervention"), with the ID team conducting rounds in the ICU every weekday. The authors compared the cost of antimicrobial agents, total hospital and ICU length of stay and inpatient mortality for the 6-month period before and after institution of these rounds between those seen versus those not seen by the ID team. Among 386 patients analyzed, 206 were admitted in the preintervention and 180 in the postintervention period. Among those seen by the ID team, there was an 18% decrease in total antimicrobial cost (P < 0.0001), 40% decrease in ICU length of stay (P = 0.1), 33% decrease in overall hospital length of stay (P = 0.03) and 34% decrease in mortality (0.04) from preintervention to postintervention period. Among those not seen by ID, there was a 39% decrease in cost among those not seen by ID (P < 0.0001), but length of ICU or hospital stay and mortality were not significantly different. Institution of dedicated ID team rounding in the ICU leads to substantial decreases in antimicrobial costs, hospital length of stay and inpatient mortality among those patients seen by the team.

Soluble ST2 and troponin I combination: Useful biomarker for predicting development of stress cardiomyopathy in patients admitted to the medical intensive care unit

ObjectiveStress cardiomyopathy (SCM) sometimes develops in patients with non-cardiac medical illness. We hypothesized that soluble suppression of tumorigenicity 2 (sST2) can predict SCM. MethodsIn 76 patients admitted to non-cardiac medical intensive care unit (MICU), echocardiography and sST2 were assessed on admission day (D0) and on the third day (D2). Cardiac troponin I (cTnI) and B-type natriuretic peptide (BNP) were measured on D0. ResultsThe SCM group (21%, 16/76) showed significantly higher cTnI, BNP, sST2 (D2), and sST2 changes than the non-SCM group. In receiver operator characteristics curve analysis, they equally predicted SCM. In 65 patients with normal cTnI, sST2 (D2) and sST2 changes predicted SCM better than cTnI or BNP. ConclusionFollow-up sST2 and the change in sST2 have additional predictive value for SCM in patients with normal cTnI. A combination strategy of sST2 and cTnI would be useful to predict SCM in patients admitted to the MICU.

Prediction of long-term outcome by measurement of serum concentration of cardiac troponins in critically ill dogs with systemic inflammation.

BackgroundMyocardial injury, detected by cardiac troponin I and T (cTnI and cTnT), has been associated with long‐term death in the noncardiac human intensive care unit (ICU).HypothesisPresence of myocardial injury predicts 1‐year case fatality in critically ill dogs with systemic inflammation.AnimalsThirty‐eight dogs with evidence of systemic inflammation and no primary cardiac disease.MethodsProspective cohort study. In dogs admitted to the ICU with evidence of systemic inflammation, blood samples were obtained at ICU admission for measurement of cTnI and cTnT, and cTnI was measured once daily during ICU hospitalization. Receiver operating characteristic (ROC) curves were used to examine prognostic capacity of admission cTnI, admission cTnT, and peak cTnI concentrations.ResultsOne‐year case fatality rate was 47% (18/38 dogs). Admission cTnI concentrations were (median [range]) 0.48 [0.004–141.50] ng/mL, and peak cTnI concentrations were 1.21 [0.021–141.50] ng/mL. Admission cTnT concentrations were 15 [<13–3744] ng/L. For each marker, non‐survivors had significantly higher concentrations than survivors (P = .0082–.038). ROC analyses revealed areas under curves [95% CI] of 0.707 [0.537–0.843] for peak cTnI and 0.739 [0.571–0.867] for admission cTnT, respectively. At the optimal cut‐off, concentrations were 1.17 ng/mL (peak cTnI) and 23 ng/L (admission cTnT), sensitivities were 72% and 72%, and specificities were 70% and 80%, respectively.Conclusions and Clinical ImportanceWhile peak cTnI and admission cTnT are significantly related to 1‐year case fatality in critically ill dogs with systemic inflammation, low sensitivities and specificities prevent their prediction of long‐term outcome in individual patients. Troponins might play a role in identification of dogs at long‐term risk of death.

Incidence and predictors of new-onset atrial fibrillation in noncardiac intensive care unit patients

BackgroundAtrial fibrillation (AF) is thought to be a relatively common arrhythmia in the setting of noncardiac intensive care unit (ICU). However, data concerning AF deriving from such populations are scarce. In addition, it is unclear which of the wide spectrum of AF predictors are relevant to the ICU setting. ObjectivesThe aim of our study was to evaluate the incidence of new-onset AF and investigate the factors that contribute to its occurrence in ICU patients. MethodsWe prospectively studied all patients admitted to our ICU during a 1-year period. Patients admitted for brief postoperative monitoring and patients with chronic or intermittent AF and AF present upon admission were excluded. A number of conditions incriminated as AF risk factors or “triggers” from demographics, medical history, present disease, and cardiac echocardiography as well as circumstances of AF onset were recorded. ResultsThe study population consisted of 133 patients (90 males). Atrial fibrillation was observed in 15% of them. Age older than 65 years (P = .001), arterial hypertension (P = .03), systemic inflammatory response syndrome (P < .001), sepsis (P = .001), left atrial dilatation (P = .01), and diastolic dysfunction (P = .04) were significantly associated with the occurrence of AF. By multivariate analysis, it was demonstrated that only older than 65 years (odds ratio, 7.0; 95% confidence interval, 2.0-24.6; P = .003) and sepsis (odds ratio, 6.5; 95% confidence interval, 2.0-21.1; P = .002) independently predict new-onset AF. Patients manifesting AF were frequently hypovolemic (30%) and had electrolyte disorders (40%) as well as elevated and rising serum C-reactive protein (70%). ConclusionA significant fraction of ICU patients manifest AF. The predictors of interest for the ICU patients might be considerably different than those of the general population and other subgroups with systemic inflammation possibly having a pivotal role.

Measurement of High-Sensitivity Troponin T in Noncardiac Medical Intensive Care Unit Patients

To assess the frequency, magnitude, and prognostic significance of elevations in cardiac troponin T in noncardiac critically ill patients, including elevations at levels below the limit of detection of traditional assays. Using a high-sensitivity assay, we measured troponin T (high-sensitivity troponin T [hsTnT]) in 451 unique patients within 12 hours of their admission to a noncardiac medical intensive care unit. Outcomes of patients, grouped by hsTnT level, were compared. Overall, 98% of the study patients had detectable levels of hsTnT (>3 ng/L), and 33% had levels above the diagnostic cutoff of a traditional fourth-generation cardiac troponin T assay. Patient groups with higher hsTnT levels had markedly higher rates of in-hospital mortality (P < .001) and longer stays in the hospital and intensive care unit (P < .01). In noncardiac critically ill patients, cardiac troponin T elevations are common but often at levels undetectable by traditional assays. hsTnT elevations predict a more complex clinical course and an increased risk of death.

Development and Implementation of a Sepsis Program

Worldwide, sepsis affects approximately 18 million people each year and carries a high mortality and morbidity rate. During the past decade, an increased incidence of sepsis has occurred in the United States. 1. Dombrovskiy VY Martin AA Sunderram J Paz HL Rapid increase in hospitalization and mortality rates for severe sepsis in the United States: a trend analysis from 1993 to 2003. Crit Care Med. 2007; 35: 1244-1250 Crossref PubMed Scopus (988) Google Scholar Approximately 750,000 Americans will experience some form of sepsis each year, and 28% will die. 2. Hotchkiss RS Karl IE The pathophysiology and treatment of sepsis. N Engl J Med. 2003; 348: 138-150 Crossref PubMed Scopus (3176) Google Scholar Sepsis especially affects the young, the old, the critically ill, and persons who are immunocompromised. 3. Gao F Daniels M Giles S Fox S The impact of compliance with six and twenty-four hour sepsis bundles on hospital mortality in patients with severe sepsis: a prospective observational study. Crit Care Med. 2005; 9: R764-R770 Crossref Google Scholar Moreover, nearly 20% of all intensive care unit (ICU) admissions are patients with severe sepsis (ie, an infection with dysfunction in 1 or more organs), and in the ICU setting, persons with sepsis have a 30% to 50% mortality rate. 1. Dombrovskiy VY Martin AA Sunderram J Paz HL Rapid increase in hospitalization and mortality rates for severe sepsis in the United States: a trend analysis from 1993 to 2003. Crit Care Med. 2007; 35: 1244-1250 Crossref PubMed Scopus (988) Google Scholar In addition, severe sepsis is the major cause of death in noncardiac ICUs and is one of the most expensive diagnoses to treat. 3. Gao F Daniels M Giles S Fox S The impact of compliance with six and twenty-four hour sepsis bundles on hospital mortality in patients with severe sepsis: a prospective observational study. Crit Care Med. 2005; 9: R764-R770 Crossref Google Scholar , 4. Rivers EP Ahrens T Improving outcomes for severe sepsis and septic shock: tools for early identification of at risk patients and treatment protocol implementation. Crit Care Clin. 2008; 23: S1-S47 Abstract Full Text Full Text PDF Scopus (65) Google Scholar , 5. Angus DC Linde-Zwirble WT Lidicker J et al. Epidemiology of severe sepsis in the United States: analysis of incidence, outcome, and associated costs of care. Crit Care Med. 2001; 29: 1303-1310 Crossref PubMed Scopus (6569) Google Scholar According to Dellinger et al, 6. Dellinger RP Levy MM Rhodes A et al. Surviving Sepsis Campaign international guidelines for management of severe sepsis and septic shock 2012. Crit Care Med. 2013; 41: 580-637 Crossref PubMed Scopus (4429) Google Scholar severe sepsis and septic shock are responsible for 1 in 4 deaths worldwide. However, the rapidity and appropriateness of therapy can affect outcomes. Echoing the Surviving Sepsis Campaign Committee, our health system believes that the utmost outcome enhancement can be created through process change and education for the persons who care for patients with sepsis. 6. Dellinger RP Levy MM Rhodes A et al. Surviving Sepsis Campaign international guidelines for management of severe sepsis and septic shock 2012. Crit Care Med. 2013; 41: 580-637 Crossref PubMed Scopus (4429) Google Scholar Lisa Dumont is Sepsis Coordinator, Southcoast Hospitals Group, New Bedford, MA. Andrew D. Harding is Associate Chief Nursing Officer, Southcoast Hospitals Group, New Bedford, MA.

A Preliminary Evaluation of Plasma B-Type Natriuretic Peptide as a Screening Test for Left Ventricular Diastolic Dysfunction in Non-Cardiac Intensive Care

Left ventricular filling and thus diastolic function are frequently monitored and managed in critical care. However, scant data exist regarding possible screening tests for diastolic dysfunction in the intensive care unit (ICU). The present study aimed to evaluate plasma b-type natriuretic peptide (BNP) as a marker of diastolic dysfunction in a single-centre cohort of 'non-cardiac' ICU patients. The ICU is non-cardiac in that it provides mixed medical/surgical services with the exception of cardiology, cardiac surgery and solid organ transplantation. Clinical data were recorded over the first 24 hours of ICU stay for 32 consecutive patients. Transthoracic echocardiogram and blood collection for BNP assay were then performed. Diastolic dysfunction was demonstrated in 34% (n=11). Mean ± standard deviation BNP values were higher with diastolic dysfunction (238 ± 195 vs 72 ± 78 pg/ml; P=0.003). A BNP threshold of >43 pg/ml yielded a sensitivity of 80% and a specificity of 59%; area under the receiver operating characteristic curve was 0.82. BNP correlated independently with E/e' (R=0.425; P=0.015) (E/e': peak early transmitral velocity [E]/early diastolic mitral annular velocity [e']) but not left ventricular ejection fraction (P=0.8), illness severity (Acute Physiological and Chronic Health Evaluation II; P=0.3) or fluid balance (P=0.4). Diastolic dysfunction was common in this cohort of non-cardiac ICU patients and was independently associated with a significantly higher BNP. The potential application as a screening test for diastolic dysfunction is likely to require a threshold lower than previously proposed for heart failure.

The incidence of seizures in patients undergoing therapeutic hypothermia after resuscitation from cardiac arrest

Non-convulsive seizures/status epilepticus occur in approximately 20% of comatose, non-cardiac arrest intensive care unit (ICU) patients, and are associated with increased mortality. The prevalence and clinical significance of seizures in comatose survivors of cardiac arrest undergoing therapeutic hypothermia is not well described. At this urban level I trauma center, every patient undergoing therapeutic hypothermia is monitored with continuous video encephalography (cvEEG). We abstracted medical records for all cardiac arrest patients treated with therapeutic hypothermia during 2010. Clinical data were extracted in duplicate. cvEEGs were independently reviewed for seizures by two board-certified epileptologists. There were 33 patients treated with therapeutic hypothermia after cardiac arrest in 2010 who met inclusion criteria for this study. Median age was 58 (range 28-86 years), 63% were white, 55% were male, and 9% had a history of seizures or epilepsy. During cooling, seizures occurred in 5/33 patients (15%, 95%CI 6%-33%). 11/33 patients (33%, 95% CI 19%-52%) had seizures at some time during hospitalization. 13/33 (39%) survived to discharge and of these, 7/13 (54%) survived to 30 days. 9/11 patients with seizures died during hospitalization, compared with 11/22 patients without seizures (82% vs. 50%; difference 32%, CI 951%-63%). No patient with seizures was alive at 30 days. Seizures are common in comatose patients treated with therapeutic hypothermia after cardiac arrest. All patients with seizures were deceased within 30 days of discharge. Routine use of EEG monitoring could assist in early detection of seizures in this patient population, providing an opportunity for intervention to potentially improve outcomes.

What Are We Missing? Arrhythmia Detection in the Pediatric Intensive Care Unit

To test the hypothesis that instituting a process of routine daily review of rhythm alarms in non-cardiac patients in the pediatric intensive care unit would yield clinically important disturbances that would otherwise go undetected. A prospective observational study was performed over a consecutive 28-day period. Total bedside monitor alarms, rhythm alarms, and heart rate (HR) trends were recorded. Rhythm alarm recordings were reviewed independently by two study team members. Medical records for patients with critical arrhythmias were reviewed to evaluate for prior knowledge of the event and to correlate with clinical data. We evaluated 86 patients (343 patient-days). There were 54,656 total monitor alarms (159.3 alarms/patient-day), of which 19,970 (37%) were rhythm alarms, including 4032 (20%) critical arrhythmias. Fifty-six percent of the critical alarms were artifactual. Seventeen of the 1786 ventricular tachycardia alarms represented true episodes that occurred in 5 patients. Two patients' care were altered as a result of detection of the arrhythmia in the review process. Eight hundred sixty-five (98%) of the 883 true critical alarms reviewed were for extreme HR. Eighty-three percent (5172) of the 6239 true non-critical alarms reviewed were HR alarms. Daily review of rhythm alarms improves detection of clinically relevant arrhythmias in non-cardiac pediatric intensive care unit patients.

Radicicol, a Hsp90 inhibitor, inhibits intestinal inflammation and leakage in abdominal sepsis

Sepsis complex syndromes remain active challenges in critical care medicine because of a deficiency in understanding the molecular basis and cellular signaling network of such infections. We hope that the 21st century will witness a revolution in discovering and targeting the cellular and molecular roots of this clinical entity. Severe sepsis with multiple organ dysfunction remains the most common cause of mortality in noncardiac intensive care units and is ranked as the 10th leading cause of death in the US [1].

Right Ventricular Diastolic Function in Patients with Thalassemia Major

Dear Editor, We read with great interest the article Echocardiography in Thalassemic Patients on Blood Transfusions and Chelation without Heart Failure written by Rodrigues et al1. They aimed to evaluate cardiac structure and function by conventional Doppler echocardiography and tissue Doppler imaging in patients with thalassemia major (TM) and no clinical evidence of heart failure. They found that left atrium volume index, mitral septal E/Em ratio and duration of reverse pulmonary vein flow were significantly higher in TM than in anemia and healthy groups. However, no differences were found in left and right ventricular structures and systolic function indexes between the groups. We believe that these findings will act as a guide for further studies regarding echocardiographic evaluation of left and right ventricular functions in patients with TM. Contrary to common belief, the right ventricle is not a passive chamber. A large number of acute and chronic diseases have been associated with RV diastolic dysfunction, including both pressure and volume overload pathologies such as primary lung disease, congenital heart disease, cardiomyopathies, ischemic heart disease, systemic diseases2,3. Only a few studies assessed the RV diastolic function. In those studies, the RV diastolic function has been evaluated using Doppler velocities of the transtricuspid flow (E, A, and E/A), tissue Doppler velocities of the tricuspid annulus (E', A', E'/A'), deceleration time, and IVRT. Most commonly used in recent studies are the tricuspid E/E' ratio, RA area or volume, and diastolic strain rate. A good correlation was shown between the tricuspid E/E' ratio and RA volume, and hemodynamic parameters. An E/E' ratio ≥4 had high sensitivity and specificity for predicting RA pressure ≥10 mm Hg in non-cardiac surgery intensive care unit patients4. The current study1 did not evaluate RV diastolic function and RA volume. Further studies should be conducted to assess RA volume and RV tissue Doppler diastolic parameters such as tricuspid E/E' ratio.

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Introduction: Heparin Induced Thrombocytopenia (HIT) in critically ill patients remains associated with increased morbidity and mortality. Yet, the burden of this disease in the intensive care unit (ICU) remains poorly understood. We sought to clarify the incidence of HIT in ICU patients. Hypothesis: HIT occurs infrequently in non-cardiac surgery ICU patients. Methods: We performed a prospective observational study in consecutive ICU patients who underwent HIT antibody testing (August 2009 – March 2012). The decision to pursue HIT diagnostically was left to the primary team. The enzyme immunoassay served as the initial screening test for HIT and by convention an optical density > 0.4 defined a positive test. The final diagnosis of HIT was confirmed by a serotonin release assay (SRA) which was performed in a central lab in all subjects. The incidence of HIT represented our primary endpoint. We then compared rates of HIT in various patient populations. Results: The cohort consisted of 218 subjects (mean age: 62.5 +/- 17.1; male gender: 56.0%). An SRA was positive and the diagnosis of HIT confirmed in 3.2% of patients tested. Physicians were more likely to order HIT in the surgical (SICU) compared to the medical service (67.5% vs 32.5%). HIT was diagnosed in 1.1% of the medical ICU patients tested vs 4.7% of the surgical ICU patients (p=0.17). Among the surgical population diagnosed with HIT, 83.3% had undergone cardiovascular surgery prior to the development of HIT. Coronary artery bypass grafting (CABG) was the most common cardiovascular surgery that predisposed to HIT (49.6%). In all non-cardiac surgery ICU patients, HIT occurred in 0.00%. Conclusions: HIT remains rare in the ICU, particularly in the general medical-surgical ICU patient population. The highest burden of this disease in the ICU is associated with those who undergo cardiovascular surgery. More importantly, patients who undergo CABG have higher risk than other general surgical ICU patients. Given the low prevalence of HIT in the non-cardiac ICU patient population, testing for HIT should only be pursued if the pre-test probability for HIT is high.

Epidemiology and management of atrial fibrillation in medical and noncardiac surgical adult intensive care unit patients

PurposeThe aim of the study was to describe the epidemiology and management of atrial fibrillation (AF) in noncardiac surgery critically ill patients in a retrospective, observational study at 3 mixed medical-surgical, university-affiliated intensive care units (ICUs). MethodsConsecutive patients admitted during a 1-year period with any documentation of AF during ICU stay were identified. Demographic data, risk factors, interventions, and outcomes were collected from the medical record. ResultsA total of 3081 patients were admitted during the 1-year study period in which 348 consecutive patients (10.5%) had documented AF. Atrial fibrillation was of new onset in 139 patients (4.5%) and preexisting in 186 patients (6.0%). Hemodynamic instability developed in 37% and 10% of patients with new-onset AF and patients with preexisting AF, respectively. Most (73%) patients with new-onset AF had at least 1 modifiable risk factor. Pharmacologic rhythm conversion was attempted in 76% and 26% of patients with new-onset AF and patients with preexisting AF, respectively. Although initially successful in 87% of new-onset cases, 42% reverted back to AF. Electrical conversion was successful in 7 (27%) of 26 and 0 (0%) of 5 of patients with new-onset AF and patients with preexisting AF, respectively. In total, 18% and 62% of patients with new-onset AF and patients with preexisting AF, respectively, who survived to ICU discharge left the ICU in AF. ConclusionsAtrial fibrillation is common but transient in most ICU patients. Electrical cardioversion is often unsuccessful, and pharmacologic rhythm conversion is often only transiently effective. Modifiable risk factors are common among these patients. Future studies are needed to address the management of AF in the ICU.

Apolipoprotein M - a new biomarker in sepsis

Sepsis is one of the leading causes of mortality in non-cardiac intensive care units, and the need for markers of progression and severity are high. Also, treatment of sepsis is highly debated and potential new targets of treatment are of great interest. In the previous issue of Critical Care Kumaraswamy and colleagues have investigated whether plasma apolipoprotein M (apoM) is affected during different grades of sepsis, septic shock and systemic inflammatory response syndrome. Interestingly, plasma apoM was significantly decreased in all groups of patients with a relationship to severity of disease. This identifies apoM as a potential new biomarker in sepsis. It also underscores the possibility that altered high-density lipoprotein in sepsis patients can affect the course of disease. Thus, since apoM is the carrier of Sphingosine-1-P (S1P), a molecule with great influence on vascular barrier function, the study presented raises the interest and relevance for further studies of apoM and S1P in relation to sepsis and inflammation.

Characterization of tracheal intubation process of care and safety outcomes in a tertiary pediatric intensive care unit*

To characterize tracheal intubation process of care and safety outcomes in a large tertiary pediatric intensive care unit using a pediatric adaptation of the National Emergency Airway Registry. Variances in process of care and safety outcome of intubation in the pediatric intensive care unit have not been described. We hypothesize that tracheal intubation is a common but high-risk procedure and that the novel pediatric adaptation of the National Emergency Airway Registry is a feasible tool to capture variances in process of care and outcomes. Prospective descriptive study. A single 45-bed tertiary noncardiac pediatric intensive care unit in a large university-affiliated children's hospital. Critically ill children who required intubation in the pediatric intensive care unit. Airway management data were prospectively collected for all initial airway management from July 2007 through September 2008 using the National Emergency Airway Registry tool tailored for pediatric application with explicit operational definitions. One hundred ninety-seven initial intubation encounters were reported (averaging one every 2.3 days). The first course intubation method was oral intubation in 181 (91.9%) and nasal in 16 (9.1%). Unwanted tracheal intubation-associated events were frequently reported (n = 38 [19.3%]), but severe tracheal intubation-associated events were rare (n = 6 [3.0%]). Esophageal intubation with immediate recognition was the most common tracheal intubation-associated event (n = 22). Desaturation <80% was reported in 51 of 183 (27.7%) and more than two intubation attempts in 30 of 196 (15.3%), both associated with occurrence of a tracheal intubation-associated event (p < .001, p = .001, respectively). Interestingly, patient age, history of difficult airway, and first attempt by resident were not associated with tracheal intubation-associated events. Unwanted tracheal intubation-associated events occurred frequently, but severe tracheal intubation-associated events were rare. Our novel registry can be used to describe the pediatric intensive care unit tracheal intubation procedural process of care and safety outcomes.