Role of thrombolysis in resuscitation.
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Austria↗
Biomedical subjects
M Baubin
Publications and source records attributed to M Baubin.
Bleeding complications associated with thrombolytic therapy in out-of-hospital cardiac arrest.
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Adult↗
Recombinant tissue plasminogen activator during cardiopulmonary resuscitation in 108 patients with out-of-hospital cardiac arrest.
BACKGROUND: Thrombolytic therapy during cardiopulmonary resuscitation (CPR) is a controversial issue in emergency medicine practice. This study was conducted to determine whether administration of recombinant tissue plasminogen activator (rt-PA) in out-of-hospital cardiac arrest of non-traumatic aetiology improves CPR outcome. METHODS AND RESULTS: A retrospective chart review of 401 patients with out-of-hospital cardiac arrest who were resuscitated by the emergency medical services (EMS) during a 6 year period was performed. A total of 108 patients received rt-PA during CPR and were compared to 216 controls, closely matched according to baseline characteristics, arrival status and ECG findings. Administration of rt-PA was optional. Return of spontaneous circulation (ROSC) occurred in 76 patients under rt-PA treatment (70.4 vs. 51.0% in controls; P=0.001). Fifty-two patients from the lysis group survived the first 24 h (48.1 vs. 32.9% in controls; P=0.003), while 27 (25.9%) survived to discharge. Autopsy reports revealed major bleeding complications in six patients receiving rt-PA treatment. Fulminant intracranial haemorrhage was observed in one patient who received rt-PA and in two cases from the control group. CONCLUSIONS: Thrombolytic therapy may improve frequency of return of spontaneous circulation substantially and increase primary survival in patients with non-traumatic cardiac arrest. Serious bleeding complications are not frequently observed under rt-PA treatment.
Aged↗
Waveform analysis of biphasic external defibrillators.
BACKGROUND AND OBJECTIVE: All internal defibrillators and some external defibrillators use biphasic waveforms. The study analysed the discharged waveform pulses of two manual and two semi-automated biphasic external defibrillators. METHODS AND RESULTS: The defibrillators were discharged into resistive loads of 25, 50 and 100 Omega simulating the patient's transthoracic impedance. The tested biphasic defibrillators differed in initial current as well as initial voltage, varying from 10.9 to 73.3 A and from 482.8 to 2140.0 V, respectively. The energies of the manual defibrillators set at 100, 150 and 200 J deviated by up to +19.1 or -28.9% from the selected energy. Impedance-normalised delivered energy varied from 1.0 to 12.5 J/Omega. Delivered energy, shock duration and charge flow were examined with respect to the total pulse, its splitting into positive and negative phases and their impedance dependence. For three defibrillators pulse duration increased with the resistive load, whereas one defibrillator always required 9.9 ms. All tested defibrillators showed a higher charge flow in the positive phase. Defibrillator capacitance varied between approximately 200 and 100 mu F and internal resistance varied from 2.0 to 7.6 Omega. Defibrillator waveform tilt ranged from -13.1 to 61.4%. CONCLUSIONS: The tested defibrillators showed remarkable differences in their waveform design and their varying dependence on transthoracic impedance.
Calibration↗
Thrombolytic therapy in sustained ventricular fibrillation.
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Adult↗
Corrigendum to "Waveforms of external defibrillators: analysis and energy contribution".
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Journal Article↗
Increased frequency of thorax injuries with ACD-CPR.
A prospective, randomised out-of-hospital study in a two-tiered system with active compression-decompression (ACD) cardiopulmonary resuscitation (CPR) versus standard (STD) CPR in patients following non-traumatic cardiac arrest was planned to test the hypothesis that ACD-CPR by the first tier may increase the occurrence of ventricular fibrillation as compared with STD-CPR. Furthermore, in a later phase of the study, sternal and rib fractures induced by both CPR methods were determined by extensive autopsy. After enrolling 90 patients the study was terminated because of a high frequency of chest injuries found at autopsy. Forty-two patients received STD-CPR from the first tier and ACD-CPR from the second tier. Thirty-three patients received ACD-CPR only by the first and the second tier, while 15 patients received STD-CPR only from the first and second tiers. In order to obtain a sufficiently large control group for autopsy findings after STD-CPR, STD-CPR was performed in an additional 33 patients within a second period of 4 months. There was no improvement in the number of patients found in ventricular fibrillation after ACD-CPR as compared to STD-CPR performed by the first tier. In patients undergoing autopsy (n = 35) there were significantly more sternal fractures with ACD-CPR versus STD-CPR (14/15 vs. 6/20; P <0.005) and rib fractures (13/15 vs. 11/20; P < 0.05) In conclusion, ACD-CPR appears to cause more CPR-related injuries than does standard CPR, but as a result of a number of limitations on this study, this fact cannot be proven beyond doubt.
Aged↗
Waveforms of external defibrillators: analysis and energy contribution.
BACKGROUND AND OBJECTIVE: Defibrillation is the most important therapy for terminating ventricular fibrillation in cardiac arrest patients. In addition to performing defibrillation at the earliest possible time, appropriate pulse energy and optimal waveform seem to be crucial for success. Emergency medical service personnel use different defibrillators and rely on their similarity of energy content. This study examined the true pulse energy content and waveform of 17 commonly used defibrillators. METHODS AND RESULTS: Defibrillation energies were selected to be 30, 200 or 360 J and defibrillators were discharged into test resistors, simulating transthoracic impedances of 25, 50 or 100 Ohms. Pulse energy deviated by up to +23% or -29% from the selected energy. Pulse energy within the initial 8 ms ranged from 90 to 30% of total pulse energy. Fourteen defibrillators utilising damped sinusoidal waveforms produced a monophasic pulse when discharged into resistances of 50 Ohms and 100 Ohms. CONCLUSIONS: Defibrillators used at the same energy settings do not necessarily produce the same defibrillation pulse energy. All but one defibrillator actually use monophasic waveforms, leaving the potential advantage of biphasic waveforms unused. Energy accuracy of defibrillators needs to be improved, and biphasic waveforms should be used more.
Calibration↗
Measuring forces and frequency during active compression decompression cardiopulmonary resuscitation: a device for training, research and real CPR.
Active compression decompression (ACD) cardiopulmonary resuscitation (CPR) is possibly a superior alternative to standard (STD) CPR, but an optimal compression and decompression pattern has to be ensured. ACD-CPR can be evaluated during CPR training sessions using commercially available manikins; however devices for recording compression and decompression forces or frequency during real CPR are lacking. Using the Ambu CardioPump without changing its mechanical characteristics, two force transducers were integrated into the ACD device. Using specially designed electronics and a portable computer, compression and decompression forces were measured and displayed continuously and compression frequency and the compression decompression phase are calculated on-line during real CPR action. All measured parameters were stored on a hard disk for later retrieval and analysis. Linearity of force measurement was better than 6% within a -250- +500 N range. The error in repeatability was below 5% thus outperforming the original mechanical force measurement system of the Ambu CardioPump. Compression frequency was calculated very accurately (error < 1%). The system has been successfully used during CPR training, during ACD-CPR in 37 corpses under research conditions and in five out-of-hospital CPR casualties. Simple and safe in use, our modified CardioPump with integrated electronics provides an important, technically advanced solution for monitoring ACD-CPR on-line. It warrants quality assurance during ACD-CPR training and in real CPR scenarios and guarantees accurate recording of compression and decompression forces and compression frequency.
Cadaver↗
Chest injuries after active compression-decompression cardiopulmonary resuscitation (ACD-CPR) in cadavers.
In a prospective study of 38 cadavers of patients older than 18 without previous chest injury or cardiopulmonary resuscitation (CPR), active compression-decompression (ACD) resuscitation manoeuvres were performed to determine possible factors influencing sternal and/or rib fractures. ACD was performed for 60 s, with compression and decompression forces being continuously recorded. A stepwise logistic regression analysis was applied. Factors analyzed were age, gender, use of a compression cushion beneath the piston of the ACD device (Ambu CardioPump), and maximal compression and decompression forces. After ACD, the cadavers were autopsied and thoracic injuries were assessed. There was a significant correlation between sternal fractures and gender (P = 0.008), and between rib fractures and age (P = 0.008). Women were found to have a higher risk for sternal fractures, whereas older patients had a higher risk for rib fractures. Maximal compression force was another factor in sternal and/or rib fracture (P = 0.048). Even though a significantly higher incidence of sternal fractures was observed when the compression cushion was used (P = 0.045), inclusion of this variable in the regression analysis only marginally improved the prediction for correct classification of sternal fractures. In conclusion, when well controlled ACD-CPR is performed in cadavers, age is the most important factor determining the incidence of rib fracture. Sternal fractures were more common in female cadavers.
Age Factors↗
Forward blood flow during cardiopulmonary resuscitation in patients with severe accidental hypothermia. An echocardiographic study.
BACKGROUND: The mechanism responsible for the forward blood flow associated with external chest compression is still controversial. Evidence for both blood flow caused by direct cardiac compression and blood flow generated by a general increase in intrathoracic pressure has been found in experimental as well as clinical studies. No data are available concerning the mechanism causing forward blood flow in hypothermic patients undergoing cardiopulmonary resuscitation. Therefore, echocardiographic findings during external chest compression in seven hypothermic arrest victims are reported. METHODS: All transesophageal echocardiographic studies performed at the Anaesthesia department between 1994 and 1997 were reviewed and seven hypothermic patients with transesophageal echocardiography performed during cardiopulmonary resuscitation were identified. RESULTS: An open mitral valve or a circumferential reduction in aortic diameter during the compression phase was found in four of seven patients, indicating that primarily an increase in intrathoracic pressure (thoracic pump mechanism) generated forward blood flow. In three patients, mitral valve closure during external chest compression indicated that direct cardiac compression (cardiac pump mechanism) contributed to forward blood flow. Two patients studied during active compression-decompression cardiopulmonary resuscitation demonstrated enhanced right ventricular filling and aortic valve opening during active decompression of the thorax. CONCLUSIONS: In contrast to normothermic arrest victims, an open mitral valve during external chest compression is a common finding during hypothermia, indicating that thoracic pump mechanism is important for forward blood flow during cardiopulmonary resuscitation in hypothermic arrest victims. Aortic valve opening in two hypothermic arrest victims suggests forward blood flow also during active decompression of the thorax with the Cardiopump.
Accidents↗
Review of active compression-decompression cardiopulmonary resuscitation (ACD-CPR). Analysis of iatrogenic complications and their biomechanical explanation.
Our review takes a critical look at the active compression-decompression technique (ACD) for cardiopulmonary resuscitation (CPR). ACD-CPR was developed following a report of successful resuscitation performed by a medical amateur using a household plunger. The efficacy of the principle of active decompression has been demonstrated by animal and human studies. Potential iatrogenic complications from the CardioPump were evaluated only when large clinical trials were already underway. Our prospective analysis of autopsy patients and systematic randomised studies in corpses prove that ACD-CPR using the CardioPump considerably increases the rate of iatrogenic complications and especially of sternum fractures. The experimental use of the CardioPump in corpses and the analysis of a variety of different parameters, especially of the rubber cushion pads mounted in the silicone cup to prevent skin abrasions, revealed a statistically significant correlation between sternum fractures and female sex (P < 0.01) and usage of the rubber cushion pad (P = 0.045). Biomechanical studies showed that the transmission of forces from the CardioPump is greatly dependent on chest shape. The lower the sternum is sunken compared with the surrounding structures, the higher the force which is transmitted via the central area of the device onto the sternum. The rubber cushion pad shortens the distance between CardioPump and sternum by 5 mm and therefore increases the sternal loading. Sex differences in the shape of the sternum and especially the thickness may account for the significant correlation between sternum fractures and female sex.
Animals↗
The prognostic significance of coma-rating, duration of anoxia and cardiopulmonary resuscitation in out-of-hospital cardiac arrest.
Early determination of outcome after successful prehospital cardiopulmonary resuscitation (CPR) is a common problem with great ethical, economic, social, and legal consequences. We prospectively investigated 112 adult patients who had been resuscitated after out-of-hospital cardiac arrest (CA). The aim of our study was to determine whether coma rating by the mobile intensive care unit (MICU) is a useful tool for outcome prediction. For neurological assessment the Innsbruck Coma Scale (ICS) was used initially and after return of spontaneous circulation (ROSC) or 20-30 min after the start of CPR, before any sedating drugs were given. The duration of anoxia and CPR were determined with the automatically recorded emergency call protocol of the dispatch centre and the protocol of the MICU. For estimation of cerebral outcome at the time of discharge from hospital we used the Glasgow-Pittsburgh Cerebral Performance Categories (CPC). Restoration of spontaneous circulation was achieved in 42 patients (37%), and 15 (13%) were discharged from hospital. The first coma rating performed immediately at the time of arrival on scene had no significant prognostic value for prediction of neurological outcome (P = 0.204) and survival (P = 0.103). The second coma rating (performed after ROSC or 20-30 min after the start of CPR), however, demonstrated a significant correlation with neurological outcome (P = 0.0000) and survival (P = 0.0000), a correlation which was comparable to both duration of anoxia and duration of CPR. In patients with out-of-hospital cardiac arrest prognostic information could be obtained with the ICS as early as 20-30 min after the start of cardiopulmonary resuscitation.
Adolescent↗
Active compression-decompression cardiopulmonary resuscitation in standing position over the patient: pros and cons of a new method.
Active compression-decompression cardiopulmonary resuscitation (ACD-CPR) has been introduced to improve outcome of CPR after cardiac arrest. Usually, ACD-CPR is performed with the rescuer kneeling beside the patient (ACD-B), but ACD-CPR with the rescuer in standing position (ACD-S) has been taught and applied in some centres in addition to conventional ACD-CPR (ACD-B). The aim of this randomised and cross-over study was to evaluate the new technique of ACD-S and to compare it with conventional ACD-B. Twelve professional rescuers (aged 30.8 +/- 7.9 years) applied both methods of ACD-CPR on a manikin. We obtained the following results. (1) Duration of CPR performance was comparable for ACD-S (13.2 +/- 7.1 min) and ACD-B (15.5 +/- 10.2 min, P = 0.48). (2) Pain in the upper extremity and pain in the vertebral column were the main reasons for break-off by the rescuers. Exhaustion was judged to be similar during ACD-S (5.3 +/- 2.3) and ACD-B (6.2 +/- 2.1; on a rating scale with 1 = no and 9 = complete exhaustion). (3) Oxygen consumption was significantly higher during ACD-S (P < 0.005), whereas heart rate and lactate levels did not differ. (4) Decompression forces were lower than compression forces. The averaged decompression forces in both methods were similar during the first 2 min and the last min. Compression forces decreased in ACD-S from 55.1 to 48.9 kp (P = 0.002) and in ACD-B from 52.8 to 47.0 kp (P = 0.069). We conclude that ACD-CPR in standing position can be considered equal to ACD-B in view of maximal duration of CPR, exhaustion of the rescuers and decompression forces. The decrease of compression forces in ACD-S and ACD-B as well as the difference between compression forces in ACD-S and ACD-B seem to be of no clinical relevance, and exhaustion was judged to be similar despite oxygen consumption being higher in ACD-S than in ACD-B.
Adult↗
Force distribution across the heel of the hand during simulated manual chest compression.
According to most published guidelines of cardiopulmonary resuscitation chest compression is performed on the lower half of the sternum by compressing the sternum with the heel of one hand and the other hand on top of the first. In all guidelines and during CPR training great importance is attributed to exact localisation of the so-called compression point. In a laboratory investigation we assessed the force distribution across the heel of the hand and defined the total breadth in contact with the sternum. In order to find out whether there is any difference in the force pattern with the right or the left hand in direct contact with the sternum we determined the resultant maximal force of that part of the heel of the hand exerting the maximal force. A total of 12 anaesthetists performed simulated chest compressions onto a flat surface covered with an integrated force sensor mat. The distance between the most ulnar part and the most radial part of the hand was determined to be 9.2 cm. Similar mean total forces were measured (right hand in contact: 644 N; left hand in contact: 621 N). In all except one anaesthetist the hypothenar part of the heel exerted a significantly higher force compared to the thenar part, independent of whether the right hand or the left hand was in contact. The distance between points of maximal force when the right hand or when the left hand in contact was 2.2 cm corresponding to the breadth of one and a half fingers. To reduce the potential risk of sternal fractures by chest compressions applied too far in a cephalad direction, we recommend use of the right hand in contact if the rescuer kneels at the right side of the patient and vice versa.
Adult↗
Active compression-decompression resuscitation: the influence of different chest geometries on the force transmission.
Active compression-decompression cardiopulmonary resuscitation (ACD-CPR) is performed using a plunger-like suction device applied onto the chest. Forces are partly transferred through the center of this device as well as through the peripheral ring of the plunger's lip seal. We analysed the load transmission distribution of the Ambu CardioPump; therefore a homemade mechanical model was used for simulating different chest geometries. We applied compression forces up to 750N on the device using a 'material testing machine', and we determined the load transferred through the central part of the device and the peripheral ring respectively. The results show that the deeper the sternum is inbeded in the chest the more force is distributed onto the peripheral ring of the plunger's vacuum cup. For a simulated flat chest, 70 N was transferred through the peripheral ring; at a simulated sternal depression of 20 mm, more than 300 N were transferred peripherally. This study points out that different chest geometries have to be considered when using CardioPump.
Cardiopulmonary Resuscitation↗
Serious complications from active compression-decompression cardiopulmonary resuscitation.
Complications arising from techniques of cardiopulmonary resuscitation (CPR) were reviewed by analysing the autopsy protocols of 25 patients who died after standard (Std) CPR and 31 who died after active compression-decompression (ACD) CPR, 15 of them preceded by Std CPR. The results can be summarised as follows: After Std CPR (n = 25) rib fractures were detected in 28%, sternal fractures in 16%, and no injuries in 68%. After ACD-CPR (n = 16) rib fractures occurred in 68%, sternal fractures in 68% and no injuries in 25%. After ACD-CPR following Std CPR(n = 15) rib fractures were detected in 93%, sternal fractures in 93%, and no patients were without thoracic fracture. In two patients severe cardiac injuries occurred clearly attributable to CPR. In conclusion cardiopulmonary resuscitation by the ACD-technique caused rib and sternal fractures more often than Std CPR and has a higher risk for iatrogenic cardiac and possible fatal injury.
Adolescent↗
Active compression-decompression cardiopulmonary resuscitation--instructor and student manual for teaching and training. Part I: The workshop.
In an attempt to standardize the teaching and training of active compression-decompression cardiopulmonary resuscitation (ACD-CPR), a group of leading emergency physicians, cardiologists, anesthesiologists, paramedics and nurses with practical, theoretical, educational, and scientific experience in the subject met in June 1995. The group was called The International Working Group of Teaching and Training Active Compression-Decompression CPR. The group was 'born' as a result of the first International Conference of Active Compression-Decompression CPR held in Copenhagen in March 1995. The following paper describes the background, development and text of and ACD-CPR course manual for both students and instructors.
Cardiopulmonary Resuscitation↗