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^r̀.     

Einführung eines integrierten Qualit?tsmanagementsystems in der pr?hospitalen Notfallmedizin

Background

The establishment of a Medical Director of Emergency Medical Services (“?rztlicher Leiter Rettungsdienst” – ?LRD) in many German regions, in Switzerland and in Tyrol, Austria, raises the question whether the implementation of an integrated quality management system (QM system) for the entire process of prehospital emergency medicine should be enforced. The authors hypothesize that the current evaluation of the structural, process and outcome quality is not sufficient enough to face future challenges, thus the implementation of an integrated QM system will be necessary.

Objective

The aim is to initiate a broad discussion on the hypothesis in order to specify the tasks of the ?LRD in the context of quality management.

Methods

By using the plan-do-check-act cycle (PDCA cycle) this article highlights and discusses the different steps to establish an integrated QM system. Explanatory examples illustrate the steps of the PDCA cycle.

Results

The implementation of an integrated quality management system in prehospital emergency medicine is described as a model and explained with examples, such as the development of a new organizational structure, a standardized documentation system and comprehensive resource and data management. In the discussion the pros and cons of such a QM system are discussed and its limitations are highlighted.

Conclusions

An integrated QM system puts the entire process of prehospital emergency medicine at the center of attention and institutionalizes the cooperation of all process partners. To promote this approach is seen as a key task of the Medical Director of Emergency Medical Services.     

Unterschätzte Gefahr am Notfallort

Background

Recent studies show that critical incidents in prehospital emergency medicine occur more often than expected. Nevertheless, risk and failure management is not mandatory. The aim of this article is to force the obligatory implementation of risk management in prehospital emergency medicine.

Methods

With the help of a case report, the theoretical basis for risk management, including the four phases of the safety circle (i.e., risk identification, risk assessment, risk accomplishment, risk monitoring), is explained.

Results

Using the example of potential medication errors, specific management measures are presented. The practical implementation of ISO NORM 26825 and the corresponding DIVI-2012 standard for the correct color of syringe labels and the revision of the checklists (vehicle and device checks) are thereby at the center of attention.

Conclusion

The case study confirms the importance of the implementation of risk management in prehospital emergency medicine. Raised safety awareness in rescue teams may increase the safety of patients and staff.     

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.     

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.     

Qualitative Forschungsmethoden in der pr?klinischen Notfallmedizin

Qualitative research methods such as focus group interviews are rarely conducted in out-of-hospital emergency medicine, but such interviews are an important tool to evaluate patient satisfaction concerning the emergency treatment. Besides the medical skills of the emergency team, social, emotional and communicative skills increase the satisfaction of emergency patients and such skills can be analyzed more easily in a face-to-face contact with patients. The evaluation and improvement of these skills would enhance the quality of the emergency treatment, in particular from the perspective of emergency patients.     

Kontinuierliche Qualitätsverbesserung in der präklinischen Notfallmedizin

In this article the first implementation step of a quality management (QM) model for continuous quality improvement (CQI), in particular the PDCA cycle, by using the example of the Medical University Innsbruck emergency department and the Austrian Red Cross, Freiwillige Rettung (Voluntary Rescue) Innsbruck (FRI) is described. Using two questionnaires concerning personnel satisfaction main problem areas were identified and improvements suggested. The results serve to discuss whether the two organizations involved fulfil the necessary conditions for the QM approach of CQI.     

The beneficial effect of basic life support on ventricular fibrillation mean frequency and coronary perfusion pressure.

BACKGROUND AND OBJECTIVE: Chest compressions before initial defibrillation attempts have been shown to increase successful defibrillation. This animal study was designed to assess whether ventricular fibrillation mean frequency after 90 s of basic life support cardiopulmonary resuscitation (CPR) may be used as an indicator of coronary perfusion and mean arterial pressure during CPR. METHODS AND RESULTS: After 4 min of ventricular fibrillation cardiac arrest in a porcine model, CPR was performed manually for 3 min. Mean ventricular fibrillation frequency and amplitude, together with coronary perfusion and mean arterial pressure were measured before initiation of chest compressions, and after 90 s and 3 min of basic life support CPR. Increases in fibrillation mean frequency correlated with increases in coronary perfusion and mean arterial pressure after both 90 s (R=0.77, P<0.0001, n=30; R=0.75, P<0.0001, n=30, respectively) and 3 min (R=0.61, P<0.001, n=30; R=0.78, P<0.0001, n=30, respectively) of basic life support CPR. Increases in fibrillation mean amplitude correlated with increases in mean arterial pressure after both 90 s (R=0.46, P<0.01; n=30) and 3 min (R=0.42, P<0.05, n=30) of CPR. Correlation between fibrillation mean amplitude and coronary perfusion pressure was not significant both at 90 s and 3 min of CPR. CONCLUSIONS: In this porcine laboratory model, 90 s and 3 min of CPR improved ventricular fibrillation mean frequency, which correlated positively with coronary perfusion pressure, and mean arterial pressure.