Biomedical subjects

Heidrun Losert

Publications and source records attributed to Heidrun Losert.

At least 19 recordsLinked to original sources

PubMed2006

Quality of cardiopulmonary resuscitation among highly trained staff in an emergency department setting.

BACKGROUND: Recent reports have highlighted the poor standard of cardiopulmonary resuscitation (CPR) achieved by health care professionals in diverse situations. We explored what can be achieved in an emergency department by highly trained permanent staff. METHODS: In a prospective observational study conducted from June 1, 2002, to August 31, 2005, 80 of 213 patients requiring CPR and admitted to the emergency department of a tertiary care hospital were eligible for study participation. Owing to several logistic problems with CPR, 133 patients could not be studied. The CPR team consisted of emergency- and critical care-trained physicians with more than 10 years of acute care experience, most of whom were instructors of European Resuscitation Council courses in basic and advanced life support. A specially designed defibrillator was used to assess the quality of CPR. RESULTS: For 80 patients, 95 data sets were available for analysis, yielding a total of 1065 minutes of cardiac arrest time. Chest compressions were performed at a rate of 114 (95% confidence interval [CI], 112-116) per minute, resulting in a mean of 96 (95% CI, 93-99) delivered chest compressions per minute. We further observed a mean hands-off ratio of 12.7% (95% CI, 12.3%-13.1%), and the hands-off ratio was linearly associated with the duration of CPR (R(2) = 0.95; mean, 4.3% increments per 5-10 minutes; P<.001). Patients were hyperventilated with a median of 18 (interquartile range, 14-24) ventilations per minute. CONCLUSIONS: Highly trained professionals in an emergency department can achieve appropriate chest compression rates during CPR with a low hands-off ratio. Increased attention must be paid in all situations to the avoidance of hyperventilation.

Aged↗

PubMed2006

High acceptance of a home AED programme by survivors of sudden cardiac arrest and their families.

PURPOSE: The feasibility and acceptance of providing sudden cardiac arrest survivors with life supporting first aid training and automated external defibrillators (AEDs) at their homes is unknown. Preliminary experiences are reported here. METHODS: Trained medical students provided life supporting first aid courses including AED training to cardiac arrest survivors. Patients were asked to invite relatives and friends to such training sessions at their home. Laerdal Little Anne and Heartstart AED Trainer were used. An AED was placed at the patients' disposal. A refresher course took place 1 year later. Questionnaires were used to evaluate the project. RESULTS: Since 1999, 88 families have been trained and provided with an AED. Immediately after the training 90% (66% "agree", 24% "maybe yes") believed they would perform first aid correctly, 1 year later 98% did so (68% "agree", 29% "maybe yes") (p=0.03). Families considered feeling much safer having an AED at home. The handling of an AED was regarded to be easy and AEDs would even be used on strangers. Only on one occasion an AED was used in a real emergency situation. CONCLUSION: Providing patients and relatives with life support first aid and AED training at their homes is feasible and has raised no major objections by the family members. All have considered handling of an AED much simpler than providing basic life support and therefore none think that it would be a major problem to use it in case of an emergency. This still has to be proven.

Adult↗

PubMed2006

Efficacy and safety of endovascular cooling after cardiac arrest: cohort study and Bayesian approach.

BACKGROUND AND PURPOSE: Recently 2 randomized trials in comatose survivors of cardiac arrest documented that therapeutic hypothermia improved neurological recovery. The narrow inclusion criteria resulted in an international recommendation to cool only a restricted group of primary cardiac arrest survivors. In this retrospective cohort study we investigated the efficacy and safety of endovascular cooling in unselected survivors of cardiac arrest. METHODS: Consecutive comatose survivors of cardiac arrest, who were either cooled for 24 hours to 33 degrees C with endovascular cooling or treated with standard postresuscitation therapy, were analyzed. Complication data were obtained by retrospective chart review. RESULTS: Patients in the endovascular cooling group had 2-fold increased odds of survival (67/97 patients versus 466/941 patients; odds ratio 2.28, 95% CI, 1.45 to 3.57; P<0.001). After adjustment for baseline imbalances the odds ratio was 1.96 (95% CI, 1.19 to 3.23; P=0.008). When discounting the observational data in a Bayesian analysis by using a sceptical prior the posterior odds ratio was 1.61 (95% credible interval, 1.06 to 2.44). In the endovascular cooling group, 51/97 patients (53%) survived with favorable neurology as compared with 320/941 (34%) in the control group (odds ratio 2.15, 95% CI, 1.38 to 3.35; P=0.0003; adjusted odds ratio 2.56, 1.57 to 4.17). There was no difference in the rate of complications except for bradycardia. CONCLUSIONS: Endovascular cooling improved survival and short-term neurological recovery compared with standard treatment in comatose adult survivors of cardiac arrest. Temperature control was effective and safe with this device.

Aged↗

PubMed2006

Thoracic impedance changes measured via defibrillator pads can monitor ventilation in critically ill patients and during cardiopulmonary resuscitation.

OBJECTIVE: Monitoring of ventilation performance during cardiopulmonary resuscitation would be desirable to improve the quality of cardiopulmonary resuscitation. To investigate the potential for measuring ventilation rate and inspiration time, we calculated the correlation in waveform between transthoracic impedance measured via defibrillator pads and tidal volume given by a ventilator. DESIGN: Clinical study. SETTING: Emergency department of a tertiary care university hospital. PATIENTS: A convenience sample of mechanical ventilated patients (n = 32), cardiac arrest patients (n = 20), and patients after restoration of spontaneous circulation (n = 31) older than 18 were eligible. INTERVENTIONS: The Heartstart 4000SP defibrillator (Laerdal Medical Cooperation, Stavanger, Norway) with additional capabilities of recording thoracic impedance changes was used. MEASUREMENTS AND MAIN RESULTS: The relationship between impedance change and tidal volume (impedance coefficient) was calculated. The mean (sd) correlations between the impedance waveform and the tidal volume waveform in the patient groups studied were .971 (.027), .969 (.032), and .967 (.035), respectively. The mean (sd) impedance coefficient for all patients in the study was .00194 (.0078) Omega/mL, and the mean (sd) specific (weight-corrected) impedance coefficient was .152 (.048) Omega/kg/mL. The measured thorax impedance change for different tidal volumes (400-1000 mL) was approximately linear. CONCLUSIONS: The impedance sensor of a defibrillator is accurate in identifying tidal volumes, when chest compressions are interrupted. This also allows quantifying ventilation rates and inspiration times. However this technology, at its present state, provides only limited practical means for exact tidal volume estimation.

Adult↗

PubMed2006

Gender modifies the influence of age on outcome after successfully resuscitated cardiac arrest: a retrospective cohort study.

Age is an important risk factor for mortality and unfavorable outcome after successfully resuscitated cardiac arrest. Other risk factors may interact with this relationship. We conducted the current study to quantify the influence of age on mortality and unfavorable neurologic outcome of patients surviving out-of-hospital cardiac arrest, and to determine the role of other confounding variables. This study was based on a cardiac arrest registry comprising all patients with witnessed out-of-hospital cardiac arrest of cardiac origin after successful resuscitation admitted to a department of emergency medicine between September 1991 and December 2004. We assessed the association between age and mortality and the degree of neurologic impairment, adjusting for multiple risk factors. We tested for interaction between age and all other risk factors with outcome. With each year of age the adjusted odds ratio for in-hospital death increased by 1.05 (95% confidence interval [CI], 1.04-1.07), and the adjusted odds ratio for an unfavorable neurologic outcome increased by 1.04 (95% CI, 1.03-1.06). Interaction between age and sex was present, and the analysis was stratified to sex. For men we found a steep risk increase for death and unfavorable outcome after being resuscitated from cardiac arrest, with the highest risk in the oldest age quartile. For women we observed only a slight risk increase for death and almost no risk increase for unfavorable outcome. Age is a strong independent risk factor for mortality and neurologic impairment after successfully resuscitated cardiac arrest. The risk increase with advancing age is much greater in men than in women. Therefore, in women, the influence of age on prognosis after cardiac arrest may not be very important, while in men it still plays an important role. This should be considered especially when treating successfully resuscitated women and discussing the prognosis with the medical team or the patient's family.

Adult↗

PubMed2006

Automated external defibrillators do not recommend false positive shocks under the influence of electromagnetic fields present at public locations.

Electromagnetic fields (EMF) reduce the signal quality of electrocardiograms and may lead to the misinterpretation by automated external defibrillators (AED). We designed this investigation as a prospective study, with a randomized sequence of AED applications on healthy volunteers. We chose busy public places where public access defibrillation was possible as test locations. Strong EMF were sought and found at train stations next to accelerating and decelerating trains. The primary outcome variable was the absolute number of shocks advised in the presence of sinus rhythm by five commonly used AED in Austria. For data analysis, the statistician was blinded in regard to the AED models tested. Data analysis was based on a per protocol evaluation. Of 390 tests run, 0 cases of false positive results occurred (95% CI: 0-0.77). AED can be regarded as safe, even with the interference of EMF present at train stations.

Defibrillators↗

PubMed2005

Influence of electromagnetic fields on function of automated external defibrillators.

OBJECTIVES: In this study, the authors tested whether electromagnetic interference (EMI) is able to impair correct electrocardiogram analysis and produce false-positive shock advice from automated external defibrillators (AEDs) when the true rhythm is sinus. METHODS: Nineteen healthy subjects were used to test five AEDs available on the Austrian market in a prospective, open, and sequence-randomized study. The primary outcome variable was the absolute number of shocks advised in the presence of EMI. The secondary outcome was the number of impaired analyses caused by incorrectly detected patient movements or electrode failure. RESULTS: Of 760 tests run, 18 (2.37%) cases of false-positive results occurred, and two of five AEDs recommended shocks in the presence of sinus rhythm. Of 760 tests run, no electrode failures occurred. There were 27 occurrences (3.55%) of motion detected by an AED in the presence of strong electromagnetic fields. CONCLUSIONS: AED models differ in their response to EMI; it may be useful to consider specific safety requirements for areas with such fields present. Working personnel and emergency medical services staff should be informed about potential risks and the possible need for patient evacuation before AEDs are attached and shock recommendations are followed.

Adult↗

PubMed2005

Cold simple intravenous infusions preceding special endovascular cooling for faster induction of mild hypothermia after cardiac arrest--a feasibility study.

OBJECTIVE: Mild therapeutic hypothermia has shown to improve neurological outcome after cardiac arrest. Our study investigated the efficacy and safety of cold simple intravenous infusions for induction of hypothermia after cardiac arrest preceding further cooling and maintenance of hypothermia by specialised endovascular cooling. METHODS: All patients admitted after cardiac arrest of presumed cardiac aetiology were screened. Patients enrolled received 2000 ml of ice-cold (4 degrees C) fluids via peripheral venous catheters. As soon as possible endovascular cooling was applied even if the cold infusions were not completed. The target temperature was defined as 33 +/- 1 degrees C. All temperatures recorded were measured via bladder-temperature probes. The primary endpoint was the time from return of spontaneous circulation to reaching the target temperature. Secondary endpoints were changes in haemodynamic variables, oxygenation, haemoglobin, clotting variables and neurological outcome. RESULTS: Out of 167 screened patients 26 (15%) were included. With a total amount of 24 +/- 7 ml/kg cold fluid at 4 degrees C the temperature could be lowered from 35.6 +/- 1.3 degrees C on admission to 33.8 +/- 1.1 degrees C. The target temperature was reached 185 +/- 119 min after return of spontaneous circulation, 135 +/- 112 min after start of infusion, and 83 +/- 85 min after start of endovascular cooling. Except for two patients showing radiographic signs of mild pulmonary edema no complications attributable to the infusions could be observed. Thirteen patients (50%) survived with favourable neurological outcome. CONCLUSION: Our results indicate that induction of mild hypothermia with infusion of cold fluids preceding endovascular cooling is safe and effective.

Advanced Cardiac Life Support↗

PubMed2005

Independent evaluation of a defibrillation outcome predictor for out-of-hospital cardiac arrested patients.

We evaluated the ability of a previously derived outcome predictor to discriminate between ECG segments corresponding to return of spontaneous circulation (ROSC) or not in validation data from 136 patients with cardiac arrest. The new data used for validation were totally independent from the predictor derivation data used in the original study. Features corresponding to those used in the development of the original outcome predictor, centroid frequency, peak power frequency, spectral flatness and energy, were computed following which a second decorrelated feature set was generated. The outcome predictor was applied to the new data with good correspondence in performance (testing) to what was expected (training) with receiver operator characteristics (ROC) areas of 0.80 and 0.79, respectively. Outcome predictor performance was reproducible. As in the present study, future testing should be performed on totally independent data not included in the design of the outcome predictor to get a reliable impression of expected performance.

Cardiopulmonary Resuscitation↗

PubMed2004

Platelet function predicts myocardial damage in patients with acute myocardial infarction.

BACKGROUND: Platelet activation is a hallmark of acute coronary syndromes. Numerous lines of evidence suggest a mechanistic link between von Willebrand factor or platelet hyperfunction and myocardial damage in patients with acute coronary syndromes. Thus, we assessed whether platelet function under high shear rates (collagen adenosine diphosphate closure times [CADP-CTs]) measured with the platelet function analyzer (PFA-100) may be enhanced in patients with myocardial infarction (MI) and whether it may predict the extent of myocardial damage as measured by creatine kinase (CK-MB) or troponin T (TnT) levels. METHODS AND RESULTS: Patients with acute chest pain or symptoms suggestive of acute coronary syndromes (n=216) were prospectively examined at an emergency department. CADP-CT was significantly shorter in patients with MI, particularly in those with an ST-segment-elevation MI (STEMI) compared with the other patient groups (unstable angina, stable coronary artery disease, or controls). Furthermore, CADP-CT and collagen epinephrine-CT at presentation were independent predictors of myocardial damage as measured by CK-MB or TnT. Patients with MI whose CADP-CT values fell in the first quartile had 3-fold higher CK-MB and TnT levels than those in the fourth quartile. CONCLUSIONS: Patients with STEMI have significantly enhanced platelet function when measured under high shear rates. CADP-CT is an independent predictor of the severity of MI, as measured by markers of cardiac necrosis. Measurement of platelet function with the PFA-100 may help in the risk stratification of patients presenting with MI.

Abciximab↗

PubMed2004

Non-traumatic aortic dissection or rupture as cause of cardiac arrest: presentation and outcome.

OBJECTIVE: To evaluate the frequency, presentation and outcome of non-traumatic aortic dissection/rupture as a cause of cardiac arrest. DESIGN: Retrospective analysis of a cardiac arrest registry in a tertiary care hospital emergency department. RESULTS: Over 11.5 years, aortic dissection/rupture was identified as the immediate cause of cardiac arrest in 46 (2,3%) out of 1990 patients with sudden cardiac arrest, primarily affecting the abdominal aorta in 25 and the thoracic aorta in 21 cases. The characteristics of the 46 patients were as follows: male gender (74%), median age 71 years (IQR 59-76), high co-morbidity (89%), previously known aortic aneurysm (33%), pulseless electric activity (70%) as initial cardiac rhythm. When performed, bedside abdominal sonography or echocardiography was almost always diagnostic. Patients with abdominal aortic dissection/rupture had abdominal (52%) and/or flank pain (32%). Patients with thoracic aortic dissection/rupture complained of chest pain (48%) or dyspnoea (19%). Return of spontaneous circulation occurred in 12 (26%) of 46 patients, emergency surgery was performed in eight of these patients, 2 (4%) survived to discharge in good neurological condition. CONCLUSIONS: Cardiac arrest caused by aortic dissection/rupture is rare, and mortality remains very high, even when circulation can be restored initially. Common features such as previously known aortic aneurysm, old age, male gender and pulseless electrical activity as initial cardiac rhythm should increase suspicion of the condition.

Age Factors↗

PubMed2004

The effect of mild therapeutic hypothermia on renal function after cardiopulmonary resuscitation in men.

BACKGROUND: Mild therapeutic hypothermia (MTH) improves neurological outcome in patients after cardiac arrest. From animal and human studies it appears that hypothermia impairs renal function. The aim of this study was to examine the effects of MTH on renal function in humans. METHODS: Patients were participants recruited in one of the centres of the hypothermia after cardiac arrest-multicenter trial. We measured serum creatinine and creatinine clearance (C(Cr)) within 24 h of MTH, at 4 hourly intervals. Patients were followed for acute renal failure and need for renal supportive therapy for 28 days. RESULTS: We included 60 patients (32 hypothermic, 28 normothermic). Median serum creatinine on admission was [[119 micromol/l (IQR 108-133)] [1.35 mg/dl (IQR 1.22-1.50)]] in hypothermic and [[114 micromol/l (IQR 99-131)] [1.29 mg/dl (IQR 1.12-1.48)]] in normothermic patients, and decreased to [[69 micromol/l (IQR 62-84)] [0.78 mg/dl (IQR 0.70-0.95)]] in the hypothermic group and to [[88 micromol/l (IQR 71-123)] [1.00 mg/dl (IQR 0.80-1.39)]] in the normothermic group within 24h. C(Cr) was decreased on admission. Within 24 h C(Cr) improved to normal values in normothermic patients [1.53 ml/s (IQR 1.15-2.35) [92 ml/min (IQR 69-141)]] and remained low in hypothermic patients [0.88 ml/s (IQR 0.63-1.38) [53 ml/min (IQR 38-83)]] (P = 0.0006). No difference was found between the groups in the development of acute renal failure or the need for renal supportive therapy. CONCLUSION: Twenty four hours of MTH was associated with a delayed improvement in renal function. This was not reflected in the serum creatinine values, which were low in the hypothermic group. This transient impaired renal function appeared to be completely reversible within 4 weeks.

Acute Kidney Injury↗

PubMed2004

Differing operational outcomes with six commercially available automated external defibrillators.

INTRODUCTION: In general automated external defibrillators (AED) are handled easily, but some untrained lay rescuers may have major problems with the use of such products. This may result in delayed shock delivery and delay in basic life support (BLS) after use of the AED. To study the effect of voice prompts and design solutions we tested the time from the first shock to the initiation of BLS for six defibrillators available in Austria. METHODS: Volunteers, who had no AED training, were evaluated to see when they delivered the first shock and how often BLS was started after the voice prompts were given by the defibrillators. RESULTS: Time to first shock delivered ranged from 78 (95% CI: 68-89) to 128 (95% CI: 110-146)s. The defibrillator-type had a significant influence on the time to first shock delivered (P < 0.0001). The proportion of volunteers who started BLS after defibrillation ranged from 93 to 33% and differed significantly between the AEDs used (P < 0.03). CONCLUSIONS: We demonstrated that there are significant differences between AEDs, concerning important operational outcomes like time to first shock and the start of BLS. Further research and development is urgently required to optimise user-friendliness and operational outcomes.

Cardiopulmonary Resuscitation↗

PubMed2004

Serial lactate determinations for prediction of outcome after cardiac arrest.

We investigated the relationship between lactate clearance and outcome in patients surviving the first 48 hours after cardiac arrest. We conducted the study in the emergency department of an urban tertiary care hospital. We analyzed the data for all 48-hour survivors after successful resuscitation from cardiac arrest during a 10-year period. Serial lactate measurements, demographic data, and key cardiac arrest data were correlated to survival and best neurologic outcome within 6 months after cardiac arrest. Parameters showing significant results in univariate analysis were tested for significance in a logistic regression model. Of 1502 screened patients, 394 were analyzed. Survivors (n = 194, 49%) had lower lactate levels on admission (median, 7.8 [interquartile range, 5.4-10.8] vs 9 [6.6-11.9] mmol/L), after 24 hours (1.4 [1-2.5] vs 1.7 [1.1-3] mmol/L), and after 48 hours (1.2 [0.9-1.6] vs 1.5 [1.1-2.3] mmol/L). Patients with favorable neurologic outcome (n = 186, 47%) showed lower levels on admission (7.6 [5.4-10.3] vs 9.2 [6.7-12.1] mmol/L) and after 48 hours (1.2 [0.9-1.6] vs 1.5 [1-2.2] mmol/L). In multivariate analysis, lactate levels at 48 hours were an independent predictor for mortality (odds ratio [OR]: 1.49 increase per mmol/L, 95% confidence interval [CI]: 1.17-1.89) and unfavorable neurologic outcome (OR: 1.28 increase per mmol/L, 95% CI: 1.08-1.51). Lactate levels higher than 2 mmol/L after 48 hours predicted mortality with a specificity of 86% and poor neurologic outcome with a specificity of 87%. Sensitivity for both end points was 31%. Lactate at 48 hours after cardiac arrest is an independent predictor of mortality and unfavorable neurologic outcome. Persisting hyperlactatemia over 48 hours predicts a poor prognosis.

Age Factors↗

PubMed2004

Inhibition of platelet function by hydroxyethyl starch solutions in chronic pain patients undergoing peridural anesthesia.

The use of hydroxyethyl starch (HES) solutions as a fluid replacement before peridural blockade may compromise blood coagulation, thus increasing the risk of neuraxial bleeding. In this prospective, double-blind, placebo-controlled, crossover study, we compared the influence of HES 130 (molecular weight in kilodalton), HES 200, and lactated Ringer's solution on platelet function and hemodynamics in chronic low back pain patients scheduled for peridural blockades. Patients received 3 test infusions of 10 mL/kg each administered IV for 30 min. Collagen/epinephrine and collagen/adenosine diphosphate were used as agonists for assessment of platelet function analyzer-closure times. Arterial blood pressure, heart rate, platelet counts, and hemoglobin levels were documented. Platelet function analyzer-closure times remained stable after lactated Ringer's solution but were significantly prolonged after HES. The platelet-inhibiting effect of HES 200 was more than that of HES 130. Hemodynamic stability was sufficiently maintained by all test infusions. In contrast to previous observations, a relevant antiplatelet effect of both low and medium molecular weight HES solutions was found in this study in chronic pain patients undergoing peridural anesthesia. Because hemostasiological competence is a prerequisite for safe neuraxial blockade, the decision of HES for intravascular fluid administration before blockade should be critically made.

Adult↗

PubMed2004

Closed suctioning system reduces cross-contamination between bronchial system and gastric juices.

In this prospective, randomized study, we evaluated whether a closed suctioning (CS) system (TrachCare) influences crossover contamination between bronchial system and gastric juices when compared with an open suctioning system (OS). The secondary aims were an analysis of the frequency of ventilator-associated pneumonia (VAP) and an analysis of alteration in gas exchange. Antibiograms were performed from tracheal secretions and gastric juice aspirates on Days 1 and 3 of intubation in 24 patients in a medical intensive care unit. Five cross-contaminations were observed in the OS group on Day 3 versus Day 1; the 5 strains shared common genotypes as determined by random amplification of polymorphic DNA. No cross-contaminations were seen in the CS group (P = 0.037). VAP occurred in 5 patients of the OS group but in none of the CS group patients (P = 0.037). Spao(2) decreased significantly in the OS group compared with presuctioning values--the opposite of the CS group. Whereas presuctioning values were comparable between groups, postsuctioning Spao(2) was significantly higher in the CS group. CS significantly reduced cross-contamination between bronchial system and gastric juices and reduced the incidence of VAP when compared with OS. Hypoxic phases can be reduced by the help of CS.

Aged↗

PubMed2003

Major bleeding complications in cardiopulmonary resuscitation: the place of thrombolytic therapy in cardiac arrest due to massive pulmonary embolism.

OBJECTIVE: Thrombolytic therapy in patients with massive pulmonary embolism (MPE) and prolonged cardiopulmonary resuscitation (CPR) is subject to debate. This study was performed to determine whether (1) thrombolytic treatment increases the risk of bleeding complications, (2) if the risk of bleeding is influenced by the duration of CPR and if (3) thrombolytic therapy improves outcome. DESIGN: Retrospective cohort study. SETTING: Emergency department of a tertiary care university hospital. PATIENTS AND METHODS: Sixty-six patients with cardiac arrest (CA) due to MPE admitted between July 1993 and December 2001. Thirty-six patients received thrombolysis (TL) and were compared with 30 patients without thrombolytic therapy. Bleeding complications were assessed by clinical evidence or autopsy. RESULTS: Major bleeding complications appear to occur more frequently in patients treated with thrombolytics (9/36 (25%) vs. 3/30 (10%)) even though the difference was statistically not significant (P=0.15). It appears that CPR duration >10 min has no adverse impact on major bleeding complications. No difference in the rate of major bleeding complications between thrombolyzed patients who had a CPR duration of </=10 or >10 min could be observed (2/8 (25%) vs. 7/28 (25%), P=0.99). In thrombolyzed patients a return of spontaneous circulation could be achieved more frequently (24/36 (67%) vs.13/30 (43%) in controls, P=0.06) and survival after 24 h was higher (19/36 (53%) vs. 7/30 (23%), P=0.01). Survival to discharge was also higher in the TL group (7/36 (19%) vs. 2/30 (7%)), but not statistically significant (P=0.15). CONCLUSION: Although severe bleeding complications tend to occur more frequently in patients undergoing TL, the benefit of this treatment might outweigh the risk of bleeding.

Adolescent↗

PubMed2003

Bedside exclusion of clinically significant recirculation volume during venovenous ECMO using conventional blood gas analyses.

STUDY OBJECTIVE: To investigate prospectively whether blood gas samples drawn from extracorporeal membrane oxygenation (ECMO) cannulae help to exclude at least clinically significant recirculation volumes in patients with acute respiratory failure. DESIGN: Feasibility study. SETTING: Intensive care unit at a university-affiliated hospital. PATIENTS: Ten consecutive adult patients suffering from severe respiratory failure and undergoing ECMO. INTERVENTIONS: The drawing (venous) ECMO cannula was placed into the inferior vena cava via a femoral vein, and the oxygenated blood was returned via the right subclavian vein by supraclavicular access directly into the right atrium. Blood gas samples were obtained from both cannulae. MEASUREMENTS AND MAIN RESULTS: The median arterial oxygen tension (PaO(2)) obtained from the arterial cannula was 537 mmHg (range, 366 to 625 mmHg), the median mixed venous oxygen tension (PvO(2)) drawn from the venous cannula was 42 mmHg (range, 25 to 54 mmHg), which was less than 10% of that observed in the arterial cannula, and also within the physiologic range of PvO(2). The ECMO flow necessary to maintain patients' oxygen saturation above 90% (4.1 L/min; range, 1.95 to 5.8 L/min) was significantly lower than the patients' cardiac output (CO; 6.2 L/min; range, 4.1 to 7.9 L/min; p < 0.001). CONSLUSIONS; We recommend obtaining blood gas samples-immediately after initiation of ECMO-from both cannulae. A PvO(2) within physiologic range and below 10% of PaO(2) rules out any clinically relevant recirculation volume.

Acute Disease↗