Early unfractionated heparin treatment in patients with STEMI - trial design and rationale

The early unfractionated heparin (UFH) treatment in patients with ST-elevation myocardial infarction (STEMI) is a single-center, open-label, randomized controlled trial. The study population are patients with STEMI that undergo primary percutaneous coronary intervention (PPCI). The trial was designed to investigate whether early administration of unfractionated heparin immediately after diagnosis of STEMI is beneficial in terms of patency of infarct-related coronary artery (IRA) when compared to established UFH administration at the time of coronary intervention. The patients will be randomized in 1:1 fashion in one of the two groups. The primary efficacy endpoint of the study is Thrombolysis in myocardial infarction (TIMI) flow grades 2 and 3 on diagnostic coronary angiography. Secondary outcome measures are: TIMI flow after PPCI, progression to cardiogenic shock, 30-day mortality, ST-segment resolution, highest Troponin I and Troponin I values at 24 hours. The safety outcome is bleeding complications. The study of early heparin administration in patients with STEMI will address whether pretreatment with UFH can increase the rate of spontaneous reperfusion of infarct-related coronary artery.

Coronary features across the spectrum of out-of-hospital cardiac arrest with ST-elevation myocardial infarction (CAD-OHCA study)

AIM

We hypothesized that adult patients with out-of-hospital cardiac arrest (OHCA) and ST-elevation myocardial infarction (STEMI) requiring prolonged resuscitation have more severe coronary artery disease (CAD) than those responding rapidly, and more severe CAD than patients with STEMI without OHCA.

METHODS

Consecutive conscious and comatose OHCA patients with STEMI after reestablishment of spontaneous circulation (ROSC), and patients with refractory OHCA undergoing veno-arterial extracorporeal membrane oxygenation (E-CPR OHCA) were compared to STEMI without OHCA (STEMI no OHCA). CAD severity was assessed by a single physician blinded to the resuscitation method, time to ROSC and level of consciousness.

RESULTS

Between 2016 and 2022, 71 conscious OHCA, 157 comatose OHCA, 50 E-CPR OHCA and 101 STEMI no OHCA underwent immediate coronary angiography. Acute culprit lesion was documented less often in OHCA (88.1% vs 97%; p = 0.009) but complete occlusion was more frequent (68.8% vs 58.4%; p = 0.038) than in STEMI no OHCA. SYNTAX score was 5.6 in STEMI no OHCA, 10.2 in conscious OHCA, 13.4 in comatose OHCA and 26.8 in E-CPR OHCA (p < 0.001). There was a linear correlation between SYNTAX score and delay to ROSC/ECMO initiation (r2 = 0.61; p < 0.001). Post PCI culprit TIMI 3 flow was comparable between the groups (≥86%). SYNTAX score was among independent predictors of 5-year survival which was significantly decreased in comatose OHCA (56.1%) and E-CPR OHCA (36.0%) compared to conscious OHCA (83.1%) and STEMI no OHCA (88.1%).

CONCLUSION

Compared to STEMI no OHCA, OHCA was associated with increased incidence of acute coronary occlusion and more complex non culprit CAD which progressively increased from conscious OHCA to E-CPR OHCA. Severity of CAD was associated with increased delays to ROSC/ECMO initiation and decreased long term survival.

Extracorporeal Life Support in Infarct-Related Cardiogenic Shock

BACKGROUND

Extracorporeal life support (ECLS) is increasingly used in the treatment of infarct-related cardiogenic shock despite a lack of evidence regarding its effect on mortality.

METHODS

In this multicenter trial, patients with acute myocardial infarction complicated by cardiogenic shock for whom early revascularization was planned were randomly assigned to receive early ECLS plus usual medical treatment (ECLS group) or usual medical treatment alone (control group). The primary outcome was death from any cause at 30 days. Safety outcomes included bleeding, stroke, and peripheral vascular complications warranting interventional or surgical therapy.

RESULTS

A total of 420 patients underwent randomization, and 417 patients were included in final analyses. At 30 days, death from any cause had occurred in 100 of 209 patients (47.8%) in the ECLS group and in 102 of 208 patients (49.0%) in the control group (relative risk, 0.98; 95% confidence interval [CI], 0.80 to 1.19; P = 0.81). The median duration of mechanical ventilation was 7 days (interquartile range, 4 to 12) in the ECLS group and 5 days (interquartile range, 3 to 9) in the control group (median difference, 1 day; 95% CI, 0 to 2). The safety outcome consisting of moderate or severe bleeding occurred in 23.4% of the patients in the ECLS group and in 9.6% of those in the control group (relative risk, 2.44; 95% CI, 1.50 to 3.95); peripheral vascular complications warranting intervention occurred in 11.0% and 3.8%, respectively (relative risk, 2.86; 95% CI, 1.31 to 6.25).

CONCLUSIONS

In patients with acute myocardial infarction complicated by cardiogenic shock with planned early revascularization, the risk of death from any cause at the 30-day follow-up was not lower among the patients who received ECLS therapy than among those who received medical therapy alone. (Funded by the Else Kröner Fresenius Foundation and others; ECLS-SHOCK ClinicalTrials.gov number, NCT03637205.).

High fidelity ECMO simulation: a reality check with reality-use of simulation in ECMO teaching program

Simulation based learning is becoming a crucial part in ECMO education. Simulation can provide a safe but also very realistic learning experience depending on simulation fidelity. In our institution we developed a simulation based ECMO training program that incorporates low- and high-fidelity simulation. Aim of this study was to evaluate effectiveness of low- and high-fidelity simulation teaching strategies in ECMO novices. We conducted four consecutive ECMO training courses that included fifty-one ECMO novices. We describe ECMO training execution and evaluate training effectiveness and perception by structured pre- and post-training questionnaires analysis. Results of our study show extremely high satisfaction rate with simulation training (4.9 ± 0.3, Lickert 5 point scale). High-fidelity simulation was perceived as very realistic and as such represents an important tool in learning immersion and experience. However, participants reported significant decline from their expectations with regard to structured approach to troubleshooting (4.7 ± 0.5 vs 4.3 ± 0.7, p = 0.02) and efficiency improvement (4.7 ± 0.5 vs 4.3 ± 0.6, p = 0.002) after high-fidelity simulation. There was also a significant decline from their expectation on self-confidence improvement (4.7 ± 0.5 vs 4.2 ± 0.7, p = 0.001). Our results therefore show, that complex high-fidelity simulation should probably be used with caution in novice participants, not to discourage them from further learning.

Coronary disease in refractory cardiac arrest undergoing resuscitation with extracorporeal membrane oxygenation (E-CPR)

BACKGROUND

Because reestablishment of spontaneous circulation (ROSC) in patients with cardiac arrest is frequently not achieved by conventional cardiopulmonary resuscitation (C-CPR), selected patients may undergo resuscitation with extracorporeal membrane oxygenation (E-CPR). We compared angiographic features and percutaneous coronary intervention (PCI) between patients undergoing E-CPR and those with ROSC after C-CPR.

METHODS

Forty-nine consecutive E-CPR patients undergoing immediate coronary angiography admitted between August 2013 and August 2022 were matched to 49 patients with ROSC after C-CPR.

RESULTS

Multivessel disease (69.4% vs 34.7%; p = 0.001),  ≥ 50% unprotected left main (ULM) stenosis (18.4% vs 4.1%; p = 0.025) and ≥1 chronic total occlusion (CTO) (28.6% vs 10.2%; p = 0.021) were more often documented in E-CPR group. There was no significant differences in the incidence, features and distribution of acute culprit lesion which was present in >90%. SYNTAX (27.6 vs 13.4; p = 0.002) and GENSINI (86.2 vs 46.0; p = 0.001) scores were increased in E-CPR group. Optimal cut-off predicting E-CPR was 19.75 for SYNTAX (sensitivity 74%, specificity 87%) and 60.50 (sensitivity 69%, specificity 75%) for GENSINI score. More lesions were treated (1.3 vs 1.1 lesions/patient; p = 0.002) and stents implanted (2.0 vs 1.3/patient; p < 0.001) in E-CPR group. Final TIMI 3 flow was comparable (88.6% vs 95.7%; p = 0.196) but residual SYNTAX (13.6 vs 3.1; p < 0.001) and GENSINI (36.7 vs 10.9; p < 0.001) scores remained increased in E-CPR group.

CONCLUSION

E-CPR patients have more multivessel disease, ULM stenosis and CTO but similar incidence, features and distribution of acute culprit lesion. Despite more complex PCI, revascularization is less complete.

In-hospital and 6-month outcomes in patients with COVID-19 supported with extracorporeal membrane oxygenation (EuroECMO-COVID): a multicentre, prospective observational study

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) has been widely used in patients with COVID-19, but uncertainty remains about the determinants of in-hospital mortality and data on post-discharge outcomes are scarce. The aims of this study were to investigate the variables associated with in-hospital outcomes in patients who received ECMO during the first wave of COVID-19 and to describe the status of patients 6 months after ECMO initiation.

METHODS

EuroECMO-COVID is a prospective, multicentre, observational study developed by the European Extracorporeal Life Support Organization. This study was based on data from patients aged 16 years or older who received ECMO support for refractory COVID-19 during the first wave of the pandemic-from March 1 to Sept 13, 2020-at 133 centres in 21 countries. In-hospital mortality and mortality 6 months after ECMO initiation were the primary outcomes. Mixed-Cox proportional hazards models were used to investigate associations between patient and management-related variables (eg, patient demographics, comorbidities, pre-ECMO status, and ECMO characteristics and complications) and in-hospital deaths. Survival status at 6 months was established through patient contact or institutional charts review. This study is registered with ClinicalTrials.gov, NCT04366921, and is ongoing.

FINDINGS

Between March 1 and Sept 13, 2020, 1215 patients (942 [78%] men and 267 [22%] women; median age 53 years [IQR 46-60]) were included in the study. Median ECMO duration was 15 days (IQR 8-27). 602 (50%) of 1215 patients died in hospital, and 852 (74%) patients had at least one complication. Multiorgan failure was the leading cause of death (192 [36%] of 528 patients who died with available data). In mixed-Cox analyses, age of 60 years or older, use of inotropes and vasopressors before ECMO initiation, chronic renal failure, and time from intubation to ECMO initiation of 4 days or more were associated with higher in-hospital mortality. 613 patients did not die in hospital, and 547 (95%) of 577 patients for whom data were available were alive at 6 months. 102 (24%) of 431 patients had returned to full-time work at 6 months, and 57 (13%) of 428 patients had returned to part-time work. At 6 months, respiratory rehabilitation was required in 88 (17%) of 522 patients with available data, and the most common residual symptoms included dyspnoea (185 [35%] of 523 patients) and cardiac (52 [10%] of 514 patients) or neurocognitive (66 [13%] of 512 patients) symptoms.

INTERPRETATION

Patient's age, timing of cannulation (<4 days vs ≥4 days from intubation), and use of inotropes and vasopressors are essential factors to consider when analysing the outcomes of patients receiving ECMO for COVID-19. Despite post-discharge survival being favourable, persisting long-term symptoms suggest that dedicated post-ECMO follow-up programmes are required.

FUNDING

None.

Coronary artery disease burden relation with the presentation of acute cardiac events and ventricular fibrillation

OBJECTIVES

Evaluate the differences in coronary artery disease (CAD) burden between patients with ischemic resuscitated, ischemic refractory VT/VF OHCA events and N/STEMI.

BACKGROUND

Refractory out-of-hospital cardiac arrest patients presenting with initial shockable rhythms (VT/VF OHCA) have the highest mortality among patients with acute cardiac events. No predictors of VT/VF OHCA refractoriness have been identified.

METHODS

A retrospective cohort design was used to assess baseline characteristics, clinical outcomes, and the angiographic severity of disease among patients with VT/VF OHCA undergoing emergent coronary angiography at the University of Minnesota Medical Center. The Gensini score was calculated for all patients to assess the angiographic burden of CAD. For patients with ischemia-related cardiac arrest, outcomes were further compared to an independent non-OHCA population presenting with N/STEMI.

RESULTS

During the study period, 538 patients were admitted after VT/VF OHCA. Among them, 305 presented with resuscitated, and 233 with refractory VT/VF. 66% of resuscitated and 70% of refractory VT/VF had an underlying, angiographically documented, ischemic etiology. Ischemic resuscitated and refractory VT/VF had significant differences in Gensini score, (80.7 ± 3.6 and 127.6 ± 7.1, respectively, p < 0.001) and survival (77.3% and 30.0%, respectively, p < 0.001). Both groups had a higher CAD burden and worse survival than the non-OHCA N/STEMI population (360 patients). Ischemic refractory VT/VF was significantly more likely to present with chronic total occlusion in comparison to both N/STEMI and ischemic resuscitated VT/VF.

CONCLUSION

Ischemia-related, refractory VT/VF OHCA has a higher burden of CAD and the presence of CTOs compared to resuscitated VT/VF OHCA and N/STEMI.

Extracorporeal life support in patients with acute myocardial infarction complicated by cardiogenic shock - Design and rationale of the ECLS-SHOCK trial

BACKGROUND

In acute myocardial infarction complicated by cardiogenic shock the use of mechanical circulatory support devices remains controversial and data from randomized clinical trials are very limited. Extracorporeal life support (ECLS) - venoarterial extracorporeal membrane oxygenation - provides the strongest hemodynamic support in addition to oxygenation. However, despite increasing use it has not yet been properly investigated in randomized trials. Therefore, a prospective randomized adequately powered clinical trial is warranted.

STUDY DESIGN

The ECLS-SHOCK trial is a 420-patient controlled, international, multicenter, randomized, open-label trial. It is designed to compare whether treatment with ECLS in addition to early revascularization with percutaneous coronary intervention or alternatively coronary artery bypass grafting and optimal medical treatment is beneficial in comparison to no-ECLS in patients with severe infarct-related cardiogenic shock. Patients will be randomized in a 1:1 fashion to one of the two treatment arms. The primary efficacy endpoint of ECLS-SHOCK is 30-day mortality. Secondary outcome measures such as hemodynamic, laboratory, and clinical parameters will serve as surrogate endpoints for prognosis. Furthermore, a longer follow-up at 6 and 12 months will be performed including quality of life assessment. Safety endpoints include peripheral ischemic vascular complications, bleeding and stroke.

CONCLUSIONS

The ECLS-SHOCK trial will address essential questions of efficacy and safety of ECLS in addition to early revascularization in acute myocardial infarction complicated by cardiogenic shock.

Breakthrough in purification of fossil pollen for dating of sediments by a new large-particle on-chip sorter

Particle sorting is a fundamental method in various fields of medical and biological research. However, existing sorting applications are not capable for high-throughput sorting of large-size (>100 micrometers) particles. Here, we present a novel on-chip sorting method using traveling vortices generated by on-demand microjet flows, which locally exceed laminar flow condition, allowing for high-throughput sorting (5 kilohertz) with a record-wide sorting area of 520 micrometers. Using an activation system based on fluorescence detection, the method successfully sorted 160-micrometer microbeads and purified fossil pollen (maximum dimension around 170 micrometers) from lake sediments. Radiocarbon dates of sorting-derived fossil pollen concentrates proved accurate, demonstrating the method's ability to enhance building chronologies for paleoenvironmental records from sedimentary archives. The method is capable to cover urgent needs for high-throughput large-particle sorting in genomics, metabolomics, and regenerative medicine and opens up new opportunities for the use of pollen and other microfossils in geochronology, paleoecology, and paleoclimatology.

Emergency veno-arterial extracorporeal membrane oxygenation (VA ECMO)-supported percutaneous interventions in refractory cardiac arrest and profound cardiogenic shock

AIMS

We investigated the spectrum of emergency veno-arterial extracorporeal membrane oxygenation (VA ECMO)-supported interventions including percutaneous coronary intervention (PCI), transcatheter aortic valve implantation (TAVI) and invasive electrophysiology (EP).

METHODS AND RESULTS

Between June 2010 and February 2020, 52 consecutive patients underwent VA ECMO implantation for refractory cardiac arrest (E-CPR) and 78 for profound cardiogenic shock. Percutaneous interventions on VA ECMO included PCI (n = 29), TAVI (n = 4) and EP (n = 1). Surgical interventions were cardiac (n = 36) or non-cardiac (n = 5). During PCI, ECMO flow was maintained at 2.7 ± 1.0 L/min. Of the 40 treated lesions, 48% were located on left anterior descending and 20% on the left main artery. An average 2.0 ± 1.8 DES/patient with diameter 3.2 ± 0.5 mm and stented length 41 ± 35 mm were implanted. PCI success was 83%. TAVI was performed in 4 patients with left ventricular ejection fraction 21 ± 10% and mean aortic valve gradient 41 ± 5 mmHg. After successful valve implantation supported by 1.4 ± 0.1 L/min ECMO flow, mean gradient decreased to 11 ± 5 mmHg without significant aortic regurgitation. In one patient radiofrequency ablation of His bundle followed by permanent pacemaker implantation was performed under ECMO flow of 2.8 L/min. Overall survival to hospital discharge with good neurological recovery was 29% in E-CPR and 44% in profound cardiogenic shock.

CONCLUSIONS

Our study showed feasibility and effectiveness of VA ECMO-supported percutaneous interventions in patients with profound hemodynamic collapse.

Increased QT Dispersion Is Linked to Worse Outcomes in Patients Hospitalized for Out-of-Hospital Cardiac Arrest

Background The incidence and mortality of out-of-hospital cardiac arrest (OHCA) remains high, but predicting outcomes is challenging. Being able to better assess prognosis of hospitalized patients after return of spontaneous circulation would enable improved management of survival expectations. In this study, we assessed the predictive value of ECG indexes in hospitalized patients with OHCA. Methods and Results PR interval and QT interval corrected by the Bazett formula (QTc) for all leads were calculated from standard 12-lead ECGs 24 hours after return of spontaneous circulation in 93 patients who were hospitalized following OHCA. PR interval and QT and QTc duration did not differentiate OHCA survivors and nonsurvivors. However, QT and QTc dispersion was significantly increased in patients who died during hospitalization compared with survivors discharged from the hospital (P<0.01). Logistic regression indicated a strong association between increased QT dispersion and in-hospital mortality (P<0.0001; area under the curve, 0.8918 for QT dispersion and 0.8673 for QTc dispersion). Multinomial logistic regression indicated that the increase of QTc dispersion correlated with worse Cerebral Performance Category scores at discharge (P<0.001; likelihood ratio, 51.42). There was also significant correlation between dispersion measures and serum potassium at the time of measurement and between dispersion measures and cumulative epinephrine administration. No difference existed regarding the number of measurable leads. Conclusions Lesser QT and QTc dispersion at 24 hours after return of spontaneous circulation was significantly associated with survival and neurologic status at discharge. Routine evaluation of QT and QTc dispersion during hospitalization following return of spontaneous circulation might improve outcome prognostication for patients hospitalized for OHCA.

Patients treated with venoarterial extracorporeal membrane oxygenation have different baseline risk and outcomes dependent on indication and route of cannulation

OBJECTIVES

To investigate the baseline risk of patients treated with Extracorporeal Cardiopulmonary Membrane Oxygenation (ECMO) in relation to cannulation strategy and indication for ECMO as well as the relation of cannulation strategy with survival and secondary hospitalization outcomes.

METHODS

Severity of illness and predicted mortality risk were assessed in 317 patients. Central cannulation was used in 52 patients unable to wean off cardiopulmonary bypass after cardiac surgery. Peripheral cannulation was used in 179 patients for extracorporeal cardiopulmonary resuscitation (eCPR) and in 86 patients who received ECMO for refractory cardiogenic shock (RCS).

RESULTS

Acute Physiology and Chronic Health Evaluation II (APACHE II) scores were significantly worse (P < 0.01) for peripheral ECMO eCPR (23.2) vs central ECMO (14.6) and vs peripheral ECMO for RCS (18.9). Survival After Venoarterial ECMO (SAVE) scores were significantly worse for peripheral ECMO for eCPR (-7.85) and RCS (-10.38) vs central ECMO (-3.97), and P < 0.01. Peripherally cannulated patients had significantly worse renal function. No significant difference existed for survival to discharge (peripheral ECMO for eCPR, 31%; central ECMO, 44%; peripheral ECMO for refractory cardiac shock, 39.5%; and P = 0.176), although centrally cannulated patients had significantly longer treatment durations compared with peripheral ECMO for eCPR.

CONCLUSIONS

Peripherally cannulated patients with eCPR had significantly worse APACHE II and SAVE scores compared to peripherally cannulated RCS or patients with central ECMO, despite having similar mortality.

Cardiopulmonary Resuscitation with Extracorporeal Membrane Oxygenation in a Patient with Profound Accidental Hypothermia and Refractory Ventricular Fibrillation

We describe a patient with severe accidental hypothermia (≤25.4°C) and prolonged refractory ventricular fibrillation, lasting at least 4 hours and 8 minutes, who underwent cardiopulmonary resuscitation with extracorporeal membrane oxygenation and survived without neurologic deficit.

Emergency percutaneous implantation of veno-arterial extracorporeal membrane oxygenation in the catheterisation laboratory

AIMS

Our aim was to describe our protocol for emergency percutaneous implantation of femoral veno-arterial extracorporeal membrane oxygenation (VA ECMO) in the catheterisation laboratory and to compare its effectiveness and safety with implantation in the intensive care unit and the operating room.

METHODS AND RESULTS

Our retrospective observational study enrolled 56 consecutive patients undergoing VA ECMO implantation in the catheterisation laboratory (n=23), the intensive care unit (n=8) and the operating room (n=25). Among patients undergoing catheterisation laboratory implantation, 11 patients had profound cardiogenic shock but preserved arterial pulsations, and 12 patients had refractory cardiac arrest undergoing automated mechanical chest compression. Using our fluoroscopy-guided protocol, arterial and venous cannulas were successfully implanted and the desired ECMO flow obtained in each patient. There was no vessel perforation/dissection. Moderate/severe GUSTO or BARC 3 and 5 bleeding occurred in 13%. Ipsilateral limb ischaemia occurred in one of eight patients (13%) with upfront perfusion sheath implantation, and in two of three patients (75%) in whom this strategy was not used (p=0.15). There was no infection at the site of cannula implantation. Complications related to implantation in the catheterisation laboratory were comparable to surgical implantation in the operating room and percutaneous implantation in the intensive care unit using ultrasound guidance.

CONCLUSIONS

Fluoroscopy-guided emergency implantation of femoral VA ECMO by an interventional cardiologist in the catheterisation laboratory is effective and safe for both patients in cardiogenic shock and those in refractory cardiac arrest.

Fulminant high altitude blindness

Prolonged altitude exposure even with acclimatization continues to present a physiological challenge to all organ systems including the central nervous system. We describe a case of a 41-year-old Caucasian female climber who suffered severe visual loss that was due to possible optic nerve pathology occurring during a high altitude expedition in the Himalayas. This case is atypical of classic high altitude cerebral oedema and highlights yet another danger of prolonged sojourn at extreme altitudes.

Contrast layering artefact mimicking aortic dissection in a patient on veno-arterial extracorporeal membrane oxygenation undergoing computed tomography scan

Interpretation and evaluation of images obtained by different contrast-enhanced diagnostic tools in patients on extracorporeal membrane oxygenation (ECMO) support can be extremely challenging due to profound pump-related alterations in haemodynamics and contrast media enhancement patterns. We present a case of a 65-year old patient on veno-arterial ECMO with a pseudo-filling defect of the arterial system on contrast-enhanced computed tomography scan, resembling aortic dissection.

DNA from soil mirrors plant taxonomic and growth form diversity

Ecosystems across the globe are threatened by climate change and human activities. New rapid survey approaches for monitoring biodiversity would greatly advance assessment and understanding of these threats. Taking advantage of next-generation DNA sequencing, we tested an approach we call metabarcoding: high-throughput and simultaneous taxa identification based on a very short (usually <100 base pairs) but informative DNA fragment. Short DNA fragments allow the use of degraded DNA from environmental samples. All analyses included amplification using plant-specific versatile primers, sequencing and estimation of taxonomic diversity. We tested in three steps whether degraded DNA from dead material in soil has the potential of efficiently assessing biodiversity in different biomes. First, soil DNA from eight boreal plant communities located in two different vegetation types (meadow and heath) was amplified. Plant diversity detected from boreal soil was highly consistent with plant taxonomic and growth form diversity estimated from conventional above-ground surveys. Second, we assessed DNA persistence using samples from formerly cultivated soils in temperate environments. We found that the number of crop DNA sequences retrieved strongly varied with years since last cultivation, and crop sequences were absent from nearby, uncultivated plots. Third, we assessed the universal applicability of DNA metabarcoding using soil samples from tropical environments: a large proportion of species and families from the study site were efficiently recovered. The results open unprecedented opportunities for large-scale DNA-based biodiversity studies across a range of taxonomic groups using standardized metabarcoding approaches.

Preparation of bone samples in the Gliwice Radiocarbon Laboratory for AMS radiocarbon dating

In the Gliwice Radiocarbon Laboratory, a system for preparation of samples for AMS dating has been built. At first it was used to produce graphite targets from plant macrofossils and sediments. In this study we extended its capabilities with the preparation of bones. We dealt with 3 methods; the first was the classical Longin method of collagen extraction, the second one included additional treatment of powdered bone in alkali solution, while in the third one carboxyl carbon was separated from amino acids obtained after hydrolysis of protein. The suitability of the methods was tested on 2 bone samples. Most of our samples gave ages > 40 kyr BP, suggesting good performance of the adapted methods, except for one sample prepared with simple Longin method. For routine preparation of bones we chose the Longin method with additional alkali treatment.