Anton N. Laggner

Platelet function in patients with acute coronary syndrome (ACS) predicts recurrent ACS

Summary.u2002 Background:u2002Platelet hyperfunction contributes to acute coronary syndromes (ACS). Thus, we hypothesized that platelet function under high shear stress predicts recurrent ACS during long‐term follow‐up of ACS patients. Patients and methods:u2002Consecutive ACS patients (nu2003=u2003208) were prospectively followed‐up for an average of 28u2003months. Platelet function was measured with the platelet function analyzer (PFA‐100®; Dade Behring, Marburg, Germany) at baseline for collagen/adenosine diphosphate closure times (CADP‐CT) and for collagen/epinephrine closure times (CEPI‐CT) after infusion of a uniform dose of 250u2003mg aspirin. Results:u2002Of the conventional risk factors, only the prevalence of diabetes was higher in ACS patients with re‐events. However, use of clopidogrel and use of beta blockers were also slightly lower in patients with re‐events (Pu2003<u20030.05). The unadjusted risk hazard ratio (HR) for re‐events was 3.3 [95% confidence interval (95% CI): 1.4–7.4; Pu2003=u20030.005] in those patients with the shortest CADP‐CT values (lowest quartile). Similarly, the risk was 2.0‐fold higher (95% CI: 1.1–3.6; Pu2003= 0.02) in ACS patients with CEPI‐CTu2003<u2003300u2003s as compared with CEPI‐CTu2003≥u2003300u2003s. Inclusion of diabetes, clopidogrel and beta blockers in a multivariate Cox regression model enhanced the predictive value of CEPI‐CT (HR: 2.7). Inclusion of von Willebrand factor levels did not alter the HR for recurrent ACS (HR: 2.1; 95% CI: 1.1–5.2; Pu2003=u20030.03) for CEPI‐CTu2003<u2003300u2003s, but reduced the HR for CADP‐CT (HR: 2.8, 95% CI: 0.8–9.8; Pu2003=u20030.11). Conclusion:u2002Shortened CT values reflect biologically relevant platelet hyperfunction in patients with ACS because they predict recurrent ACS.

Hemostasis in cardiac arrest patients treated with mild hypothermia initiated by cold fluids

AIM OF THE STUDYnApplication of mild hypothermia (32-33 degrees C) has been shown to improve neurological outcome in patients with cardiac arrest. However, hypothermia affects hemostasis, and even mild hypothermia is associated with bleeding and increased transfusion requirements in surgery patients. On the other hand, crystalloid hemodilution has been shown to induce a hypercoagulable state. The study aim was to elucidate in which way the induction of mild therapeutic hypothermia by a bolus infusion of cold crystalloids affects the coagulation system of patients with cardiac arrest.nnnMETHODSnThis was a prospective pilot study in 18 patients with cardiac arrest and return of spontaneous circulation (ROSC). Mild hypothermia was initiated by a bolus infusion of cold 0.9% saline fluid (4 degrees C; 30ml/kg/30min) and maintained for 24h. At 0h (before hypothermia), 1, 6 and 24h we assessed coagulation parameters (PT, APPT), platelet count and performed thrombelastography (ROTEM) after in vitro addition of heparinase.nnnRESULTSnA total amount of 2528 (+/-528)ml of 0.9% saline fluid was given. Hematocrit (p<0.01) and platelet count (-27%; p<0.05) declined, whereas APTT increased (2.7-fold; p<0.01) during the observation period. All ROTEM parameters besides clotting time (CT) after 1h (-20%; p<0.05) did not significantly change.nnnCONCLUSIONnMild hypothermia only slightly prolonged clotting time as measured by rotation thrombelastography. Therefore, therapeutic hypothermia initiated by cold crystalloid fluids has only minor overall effects on coagulation in patients with cardiac arrest.

Accuracy of Noninvasive Multiwave Pulse Oximetry Compared With Carboxyhemoglobin From Blood Gas Analysis in Unselected Emergency Department Patients

STUDY OBJECTIVEnAccurate and timely diagnosis of carbon monoxide (CO) poisoning is difficult because of nonspecific symptoms. Multiwave pulse oximetry might facilitate the screening for occult poisoning by noninvasive measurement of carboxyhemoglobin (COHb), but its reliability is still unknown. We assess bias and precision of COHb oximetry compared with the criterion standard blood gas analysis.nnnMETHODSnThis was a prospective diagnostic accuracy study according to STARD (Standards for the Reporting of Diagnostic accuracy studies) criteria, performed at a tertiary care hospital emergency department. We included all patients for whom both invasive and noninvasive measurement within 60 minutes was available, regardless of their complaints, during a 1-year period.nnnRESULTSnOne thousand five hundred seventy-eight subjects were studied, of whom 17 (1.1%) received a diagnosis of CO poisoning. In accordance with this limited patient cohort, we found a bias of 2.99% COHb (1.50% for smokers, 4.33% for nonsmokers) and a precision of 3.27% COHb (2.90% for smokers, 2.98% for nonsmokers), limits of agreement from -3.55% to 9.53% COHb (-4.30% to 7.30% for smokers, -1.63% to 10.29% for nonsmokers). Upper limit of normal cutoff of 6.6% COHb had the highest sensitivity in screening for CO poisoning. Smoking status and COHb level had the most influence on the deviation between measurements.nnnCONCLUSIONnMultiwave pulse oximetry was found to measure COHb with an acceptable bias and precision. These results suggest it can be used to screen large numbers of patients for occult CO poisoning.

CPR in medical schools: learning by teaching BLS to sudden cardiac death survivors – a promising strategy for medical students?

BackgroundCardiopulmonary resuscitation (CPR) training is gaining more importance for medical students. There were many attempts to improve the basic life support (BLS) skills in medical students, some being rather successful, some less. We developed a new problem based learning curriculum, where students had to teach CPR to cardiac arrest survivors in order to improve the knowledge about life support skills of trainers and trainees.MethodsMedical students who enrolled in our curriculum had to pass a 2 semester problem based learning session about the principles of cardiac arrest, CPR, BLS and defibrillation (CPR-D). Then the students taught cardiac arrest survivors who were randomly chosen out of a cardiac arrest database of our emergency department. Both, the student and the Sudden Cardiac Death (SCD) survivor were asked about their skills and knowledge via questionnaires immediately after the course. The questionnaires were then used to evaluate if this new teaching strategy is useful for learning CPR via a problem-based-learning course. The survey was grouped into three categories, namely Use of AED, CPR-D and Training. In addition, there was space for free answers where the participants could state their opinion in their own words, which provided some useful hints for upcoming programs.ResultsThis new learning-by-teaching strategy was highly accepted by all participants, the students and the SCD survivors. Most SCD survivors would use their skills in case one of their relatives goes into cardiac arrest (96%). Furthermore, 86% of the trainees were able to deal with failures and/or disturbances by themselves. On the trainers side, 96% of the students felt to be well prepared for the course and were considered to be competent by 96% of their trainees.ConclusionWe could prove that learning by teaching CPR is possible and is highly accepted by the students. By offering a compelling appreciation of what CPR can achieve in using survivors from SCD as trainees made them go deeper into the subject of resuscitation, what also might result in a longer lasting benefit than regular lecture courses in CPR.

Massive pulmonary embolism leading to cardiac arrest is associated with consumptive coagulopathy presenting as disseminated intravascular coagulation

See also Levi M. Disseminated intravascular coagulation or extended intravascular coagulation in massive pulmonary embolism. This issue, pp 1475–6; Thachil J. DIC score predicts mortality in massive clot coagulopathy as a result of extensive pulmonary embolism: a rebuttal. This issue, pp 1657–8; Leitner JM, Janata‐Schwatzek K, Spiel AO, Sterz F, Laggner AN, Jilma B. DIC score predicts mortality in massive clot coagulopathy as a result of extensive pulmonary embolism: reply to a rebuttal. This issue, pp 1658–9.

Cardiac arrest due to accidental hypothermia—A 20 year review of a rare condition in an urban area

BACKGROUNDnAccidental hypothermic cardiac arrest is associated with unfortunate prognosis and large studies are rare. We therefore have performed an outcome analysis in patients that were admitted to Vienna University Hospital with the diagnosis of accidental hypothermic cardiac arrest.nnnMETHODSnThis study employed a retrospective outcome analysis of prospectively collected data in a selected cohort of hypothermic cardiac arrest patients. We screened 3800 cardiac arrest patients, treated at our department between 1991 and 2010, for eligibility. Inclusion criteria were cardiac arrest with a body core temperature ≤28 °C and return of spontaneous circulation.nnnRESULTSnA total of 18 patients who achieved return of spontaneous circulation were analysed. Nine patients (50%) achieved survival in good neurologic condition (defined as cerebral performance category CPC 1 or 2). Accidental hypothermia with consecutive cardiac arrest was caused by intoxication in most cases (67%). These patients had a better outcome than patients with other causes of accidental hypothermic cardiac arrest (OR=28; 95%KI 2-37.9; p<0.01). Hypothermia associated typical ECG changes after return of spontaneous circulation (Osborne waves) were more frequent in the surviving population (OR 16; 95%KI 1.3-19.5; p=0.05).nnnCONCLUSIONSnAccidental hypothermic cardiac arrest in a central European urban area is rare. Prognosis was excellent in patients where hypothermic cardiac arrest was caused by intoxication.

Transport with ongoing cardiopulmonary resuscitation may not be futile

BACKGROUNDnDespite it being generally regarded as futile, patients are regularly brought to the emergency department with ongoing cardiopulmonary resuscitation (CPR).nnnMETHODSnLong-term outcome and its predictors in patients who were transported during ongoing CPR were evaluated in an observational study. Adult patients with non-traumatic cardiac arrest admitted to the Department of Emergency Medicine of a tertiary-care facility after transport with ongoing chest compression were retrospectively analysed. Multivariate analysis of epidemiological variables, treatment, blood gas values on admission, cause of arrest, and location of arrest was performed to find factors that were predictive for favourable long-term outcome (6-month survival, best cerebral performance category 1 or 2).nnnRESULTSnOver 15 yr (1991-2006), a total of 2643 patients were treated after cardiac arrest. Of these, 327 patients received chest compressions during transport and were analysed (out-of-hospital cardiac arrest: n=244, in-hospital: n=83; the remaining 2316 patients were either stabilized before transport or suffered their arrest in our department). Return of spontaneous circulation was achieved in 31% of patients (n=102). Of these, 19 (19%) had favourable long-term outcome (6% of total). Independent predictors of good outcome were age, witnessed arrest, amount of epinephrine, and initial shockable rhythm. Among the patients with cardiac origin of arrest, 11 out of 197 patients (6%) survived; pulmonary origin, 4 out of 46 patients (9%); hypothermic arrest, 1 of 10 patients (10%); and intoxications, one out of nine patients (11%).nnnCONCLUSIONSnPost-resuscitation care in patients who receive CPR during transport is not futile. Once restoration of spontaneous circulation is established, one out of five patients will have good long-term outcome.

A prediction tool for initial out-of-hospital cardiac arrest survivors

AIMnImprovement in predicting survival after out-of-hospital cardiac arrest is of major medical, scientific and socioeconomic interest. The current study aimed at developing an accurate outcome-prediction tool for patients following out-of-hospital cardiac arrests.nnnMETHODSnThis retrospective cohort study was based on a cardiac arrest registry. From out-of-hospital cardiac arrest patients (n=1932), a set of variables established before restoration of spontaneous circulation was explored using multivariable logistic regression. To obtain reliable estimates of the classification performance the patients were allocated to training (oldest 80%) and validation (most recent 20%) sets. The main performance parameter was the area under the ROC curve (AUC), classifying patients into survivors/non-survivors after 30 days. Based on rankings of importance, a subset of variables was selected that would have the same predictive power as the entire set. This reduced-variable set was used to derive a comprehensive score to predict mortality.nnnRESULTSnThe average AUC was 0.827 (CI 0.793-0.861) for a logistic regression model using all 21 variables. This was significantly better than the AUC for any single considered variable. The total amount of adrenaline, number of minutes to sustained restoration of spontaneous circulation, patient age and first rhythm had the same predictive power as all 21 variables. Based on this finding, our score was built and had excellent predictive accuracy (the AUC was 0.810), discriminating patients into 10%, 30%, 50%, 70%, and 90% survival probabilities.nnnCONCLUSIONnThe current results are promising to increase prognostication accuracy, and we are confident that our score will be helpful in the daily clinical routine.

Admission of out-of-hospital cardiac arrest victims to a high volume cardiac arrest center is linked to improved outcome ☆

AIMnCardiac arrest centers have been associated with improved outcome for patients after cardiac arrest. Aim of this study was to investigate the effect on outcome depending on admission to high-, medium- or low volume centers.nnnMETHODSnAnalysis from a prospective, multicenter registry for out of hospital cardiac arrest patients treated by the emergency medical service of Vienna, Austria. The frequency of cardiac arrest patients admitted per center/year (low <50; medium 50-100; high >100) was correlated to favorable outcome (30-day survival with cerebral performance category of 1 or 2).nnnRESULTSnOut of 2238 patients (years 2013-2015) with emergency medical service resuscitation, 861 (32% female, age 64 (51;73) years) were admitted to 7 different centers. Favorable outcome was achieved in 267 patients (31%). Survivors were younger (58 vs. 66 years; p<0.001), showed shockable initial heart rhythm more frequently (72 vs. 35%; p<0.001), had shorter CPR durations (22 vs. 29min; p<0.001) and were more likely to be treated in a high frequency center (OR 1.6; CI: 1.2-2.1; p=0.001). In multivariate analysis, age below 65 years (OR 15; CI: 3.3-271.4; p=0.001), shockable initial heart rhythm (OR 10.1; CI: 2.4-42.6; p=0.002), immediate bystander or emergency medical service CPR (OR 11.2; CI: 1.4-93.3; p=0.025) and admission to a center with a frequency of >100 OHCA patients/year (OR 5.2; CI: 1.2-21.7; p=0.025) was associated with favorable outcome.nnnCONCLUSIONSnHigh frequency of post-cardiac arrest treatment in a specialized center seems to be an independent predictor for favorable outcome in an unselected population of patients after out of hospital cardiac arrest.

Our paper 20 years later: from acute renal failure to acute kidney injury—the metamorphosis of a syndrome

AbstractPurposeMore than 20xa0years ago we reported an analysis of a case series of elderly critically ill patients with acute kidney injury (AKI)—then termed acute renal failure. At that time, AKI was regarded as a “simple” complication, but has since undergone a fundamental change and actually has become one of the central syndromes in the critically ill patient.MethodsWe have analyzed elderly patients above 65xa0years of age with an AKI defined as serum creatinine above 3xa0mg/dl corresponding to modern KDIGO stagexa03, most of them requiring renal replacement therapy (RRT). Using an extremely complete data set the diagnosis differentiated the underlying disease entity, the dominant cause of AKI, acute and chronic risk factors (comorbidities). Special aspects such as severity of disease, early AKI at admission versus late AKI, early versus later start of RRT, AKI not treated by RRT in spite of indication for RRT, various measures of short-term and long-term prognosis, renal outcome, patients dying with resolved AKI, and causes of death were evaluated.ResultsCrude mortality was 61xa0% which corresponds to modern studies with gross variation among the different subgroups. Age per se was not a determinant of survival either within the group of elderly patients or as compared to younger age groups. Despite an increase in mean agen and disease severity during the observation period prognosis improved. A total of 17xa0% of patients developed a chronic kidney disease. Long-term survival as compared to the general population was low.ConclusionsA look back at the last two decades illustrates a remarkable evolution or rather metamorphosis of a syndrome. AKI has evolved as a central syndrome in intensive care patients, a systemic disease process associated with multiple systemic sequels and extra-renal organ injury and exerting a pronounced effect on the course of disease and short- and long-term prognosis not only of the patient but also of the kidney. Moreover, the “non-renal-naïve” elderly patient with multiple comorbidities has become the most frequent ICU patient in industrialized nations.