Should we use automated external defibrillators in hospital wards?

Automated external defibrillators (AEDs) have shown to improve survival after cardiopulmonary arrest (CPA) in many, but not all clinical settings. A recent study reported that the use of AEDs in-hospital did not improve survival. The current retrospective study reports the results of an in-hospital AED programme in a university hospital, and focuses on the quality of AED use. At Ghent University Hospital 30 AEDs were placed in non-monitored hospital wards and outpatient clinics treating patients with non-cardiac problems. Nurses were trained to use these devices. From November 2006 until March 2011, the AEDs were used in 23 of 39 CPA cases, in only one patient the presenting heart rhythm was ventricular fibrillation and this patient survived. Pulseless electrical activity was present in 14 patients (four survived) and asystole in eight patients (one survived). AEDs were attached to eight patients without CPA, and in 16 patients with CPA AED was not used. The quality of AED use was often suboptimal as illustrated by external artifacts during the first rhythm analysis by the AED in 30% (7/23) and more than 20 seconds delay before restart of chest compressions after the AED rhythm analysis in 50% (9/18). The literature data, supported by our results, indicate that in-hospital AED programmes are unlikely to improve survival after CPA. Moreover, their use is often suboptimal. Therefore, if AEDs are introduced in a hospital, initial training, frequent retraining and close follow-up are essential.

Training to deeper compression depth reduces shallow compressions after six months in a manikin model.

INTRODUCTION: Studies show that students, trained to perform compressions between 40 and 50mm deep, often do not achieve sufficient depth at retention testing. We hypothesized that training to achieve depths >50mm would decrease the proportion of students with depth <40mm after 6 months, compared to students trained to a depth interval of 40-50mm. METHODS: A basic life support (BLS) self-learning station was attended by 190 third year medicine students. They were first offered the possibility to refresh their skills, following the instructions of a 15min abbreviated Mini Anne™ video (Laerdal, Norway) using a full size torso and a face shield. This was followed by further training using Resusci Anne Skills Station™ software (Laerdal, Norway). Voice feedback was provided according to randomisation to a standard group (SG) 40-50mm and a deeper group (DG) >50mm. Quality of compressions was tested after 6 months. RESULTS: The SG and DG groups consisted of 90 (67% female) and 100 (58% female) participants respectively. At the end of training, all students reached the target depth without overlap between groups. After 6 months, the proportion of students achieving a depth <40mm was 26/89 (29%) in the SG vs. 12/89 (14%) in the DG (P=0.01). The proportion of students with a depth >50mm was 5/89 (6%) for the SG and 44/89 (49%) in the DG (P<0.001). CONCLUSIONS: The educational strategy to train students to a deeper depth, reduced shallow compressions 6 months after training.

Determinants of the quality of basic life support by hospital nurses.

INTRODUCTION: Good quality basic life support (BLS) results in better survival. BLS is a core competence of nurses but despite regular refresher training, the quality of BLS is often poor and the reasons for this are not well known. We therefore investigated the relation between BLS quality and some of its potential determinants. MATERIALS AND METHODS: During a BLS refresher course, 296 nurses from non-critical care wards completed a questionnaire including demographic data and a "self-confidence" score. Subsequently, they performed a BLS test on a manikin connected to a PC using Skillreporting System software (Laerdal, Norway). The following variables were recorded: number of ventilations/min, tidal volume, number of compressions/min, compression rate, compression depth, "good ventilation" (n >or=4 min(-1) and tidal volume=700-1000 ml) and "good compression" (n >or=40 min(-1) and rate=80-120 min(-1) and compression depth=40-50mm). To detect independent determinants of BLS quality, associations between the demographic data and the objective variables of BLS quality were examined. RESULTS: Forty-three percent of the nurses rated their confidence as good or very good. Male gender was associated with good compression (P<0.001). Greater self-confidence was also associated with good ventilation (P<0.03) and with good compression (P<0.001). A short time since last BLS training was associated with a higher number of ventilations/min (P=0.01). A short time since last experience of CPR was associated with a higher number of compressions (P<0.01). CONCLUSIONS: Male gender, greater self-confidence, recent BLS training and recent CPR were associated with better quality of BLS.

A survey on alcohol and illicit drug abuse among emergency department patients.

Alcohol and illicit drug abuse are major health care problems frequently leading to emergency department admission. The aims of this survey were (1) to determine for the Ghent University Hospital how frequently substance abuse contributed to emergency department admissions, (2) to describe the most important clinical features of these patients and (3) to determine how frequently these patients were referred to appropriate psychiatric services. All 1,941 patients attending the emergency department during the month of September 2003 were registered by the attending emergency department personnel. After exclusion of 8 cases, 1,933 patients were included: 198 (10%) with substance abuse leading to the emergency department admission (= INTOX group) and 1,735 (90%) in the NON-INTOX group. Males and the 21-50 years age group were overrepresented in the INTOX group. Patients with substance abuse were also overrepresented during the night, but not during the weekend. Among the patients from the INTOX group the most frequent reason for the emergency department visit was a psychiatric problem (102/198; 51%). Traumatic lesions related to a fight (n= 19), to a traffic accident (n= 17) and to leisure time activities (n=30) were also frequent. In most patients, only alcohol was abused (144/198; 73%), most frequently chronically (102/144; 71%). In 13% (26/198), there was only illicit drug use, and in 14% (28/198) alcohol abuse was combined with illicit drug use. Among the 54 patients with illicit drug use (with or without alcohol abuse) the most frequently reported drugs were cannabis (54%), cocaine (41%), amphetamines (39%) and opiates (39%). With regard to referral to appropriate psychosocial services it was striking that 53% (19/36) of trauma patients with chronic substance abuse were not offered that type of help. We conclude that abuse of alcohol--and to a much lesser degree illicit drugs--is a frequent cause of emergency department admissions. Our data may help to convince and/or reinforce health care policy makers, emergency department medical directors and the public that alcohol consumption (much more than illicit drugs) is responsible for avoidable morbidity and mortality, and that well-co-ordinated strategies against unhealthy alcohol use are urgently needed. In this respect, the importance of detection and referral of emergency department patients with unhealthy alcohol use should be stressed.

Unreliable post event report from an automated external defibrillator.

Medical supervision of the use of automated external defibrillators (AEDs) is possible by the incorporation of a solid state memory system recording electrocardiography (ECG) tracings and information about the operation of the device. Since a post event report suggested inappropriate AED use erroneously, the information storage and printing processes of the Laerdal AED system were investigated. This analysis strongly suggests (yet unpredictable) incompatibilities between the software built in the solid state memory modules and the different components of the printing system. Although no problems were encountered during the resuscitation attempts, these findings may be clinically relevant because an unreliable post event report from a solid state memory module may lead to erroneous criticism of an AED user.

Thrombosis of an aneurysm of the basilic vein upper extremity venous aneurysm.

We present the case of a large venous aneurysm in the upper extremity of a 71-year-old male. The patient presented with acute thrombosis of the aneurysm, which was only diagnosed at operation. Aetiology, diagnosis and treatment of this uncommon lesion are discussed.

Anomalous ECG downloads from semi-automatic external defibrillators.

The coincidental print-out by two different Laerdal systems (subsequently called 'system A' and 'system B') of the same medical control module (MCM) for a Laerdal Heartstart 2000 semi-automatic external defibrillator (SAED) led to the discovery of three deficiencies in the information storage and printing processes. First, we noted that the impedance reported via system A was consistently higher. Second, we found the attachment of 'mysterious' ECG samples in the reports from system B, but not from system A. A third problem was the unpredictable (in)ability of system B to print out the information from the MCMs. Further investigations with help from the company suggested that the above-mentioned problems were caused by incompatibilities between the software in the different parts of equipment used (i.e. SAED devices, MCMs, printing systems and a computer program to store the information in a database). These observations demonstrate the need for strict medical supervision on all aspects of a SAED project, and for feed-back from clinicians to manufacturers.

When an AED meets an ICD... Automated external defibrillator. Implantable cardioverter defibrillator.

The chances of prehospital care providers being confronted with a patient with an implantable cardioverter defibrillator (ICD) are increasing and so care providers must receive proper training. Based on observations made during the resuscitation of a patient with an ICD using an automated external defibrillator (AED) some technical features and possible interactions of ICDs and AEDs are highlighted. Furthermore, we discuss the key points of basic knowledge, safety, and treatment protocols for cardiac arrest and other situations required for practical training in the ICD for prehospital care providers.

The effect of semi-automatic external defibrillation by emergency medical technicians on survival after out-of-hospital cardiac arrest: an observational study in urban and rural areas in Belgium.

The introduction of semi-automatic external defibrillators (SAEDs) allowed emergency medical technicians (EMTs) to deliver electroshocks in cases of out-of-hospital ventricular fibrillation (VF) or ventricular tachycardia (VT), often many minutes before the arrival of the mobile intensive care unit (MICU) team. In this observational study we report on the results obtained by the EMTs from the fire departments of Gent, Aalter and Brugge. In Gent, an SAED project started in May 1991. By December 1995, the SAED's electrodes had been attached in 367 cardiac arrest patients. The first rhythm detected by the device was asystole or electromechanical dissociation (EMD) in 241 patients (66%): only 5 of these patients survived to hospital discharge (2%). In the remaining 126 VF/VT cases (34%) the survival rate was 21% (26/126). In 14 of these 26 patients the shock(s) delivered by the EMTs restored spontaneous circulation before the arrival of the MICU team, with only venous cannulation and/or intubation being performed by the MICU team. In 4 other VF patients, the shock(s) delivered by EMTs converted the VF, with the MICU team successfully taking care of VF/VT relapses or postcountershock EMD. In the remaining 8 VF/VT cases, only the MICU attempts could resuscitate the patient. The SAED project in Aalter was set up in April 1993. By December 1995, care was taken for only 21 patients. None of the 4 VF/VT patients and the 17 asystole/EMD patients survived. In Brugge, there were 240 cardiac arrest cases treated with SAED between January 1991 and December 1995. Among the 89 VF/VT cases, there were 20 survivors (22%): 8 cases survived thanks to SAED shock(s) delivered by EMTs, in 3 cases survival was due to the combination of SAED shock(s) by EMTs and extensive ALS treatment by the MICU team, and in 9 cases restoration of spontaneous circulation was only obtained after application of ALS techniques by the MICU team. This observational study seems to show a beneficial effect of the introduction of SAED in Gent and Brugge. In Aalter the number of treated cases is tool low to draw conclusions. Anyhow, the global survival rate in the three areas remains low. Therefore, more efforts are needed to strengthen the other links of the chain of survival (early access to the emergency medical services-system, early basic cardiopulmonary resuscitation and early advanced life support.

A sudden awakening from a near coma after combined intake of gamma-hydroxybutyric acid (GHB) and ethanol.

OBJECTIVE: A case of a sudden awakening from a near coma after combined intake or gamma-hydroxybutyric acid (GHB) (125 micrograms/mL), ethanol (134 mg/dL), and cannabinoids is described. METHODS: GHB was determined by gas chromatography-mass spectrometry after acetonitrile precipitation and derivation with N-methyl-N-trimethylsilyltrifluoroacetamide, using valproic acid as the internal standard. CONCLUSION: The described case illustrates the consequences of GHB overdose. GHB overdose should be considered in every case of unexplained sudden coma, i.e., without any evidence of head injury, intake of coma-inducing drugs, or increasing intracranial pressure. GHB overdose will be missed by routine toxicological screening.

Do victims of an out-of-hospital cardiac arrest benefit from a training program for emergency medical dispatchers?

In this paper, we assessed the effects of a training course for emergency medical dispatchers on the handling of out-of-hospital cardiac arrest cases in the dispatch center of a two-tiered emergency medical services system. A total of 112 cardiac arrest cases were studied; 64 before and 48 after the training course. Before the course, all relevant information was obtained in 36% of cases, only partial information in 56% and no useful medical information in 8%. The corresponding figures after the training program were 62, 38 and 0%, respectively (2 x 3 chi2 test, P = 0.01). Trends towards an increase in the percentage of cases in which a second-tier team was sent immediately after the initial call (58 vs 75%; chi2 test, P = 0.06) and towards shorter overall intervals between receipt of the call and dispatch of the second-tier team (logrank test, P = 0.10) were noticed. Similarly, the survival rate increased from 2% before, to 8% after the training course (chi2 test with Yates' correction, P = 0.24). We conclude that our training program for emergency medical dispatchers produced some beneficial effects.

Failure of nimodipine to prevent brain damage in a global brain ischemia model in the rat.

In view of our negative results with the calcium antagonist nimodipine as a cerebroprotective agent in a cardiopulmonary resuscitation model in the rat, we examined the protective effects of nimodipine in the four-vessel (carotid and vertebral) occlusion model, a model of global brain ischemia without important cardiovascular depression. Survival and neurological status were monitored and after 72 h the hippocampus was resected and examined for histological evaluation. The animals were treated blindly and randomly with either nimodipine, its solvent or saline given subcutaneously. In two separate studies, high doses (total dose: 5 mg/kg) or low doses of nimodipine (total dose: 1.6 mg/kg) were administered. In the high dose series, the survival rates at 72 h in the nimodipine group, the saline group and the solvent group were 4% (2/44), 19% (7/37) and 20% (8/41), respectively; in the low dose series, the figures were 26% (13/50), 34% (15/44) and 39% (18/46), respectively. The differences between nimodipine, solvent and saline were not statistically significant. Likewise, no differences in neurological status or histological brain damage were found. These data suggest that nimodipine offers no cerebral protection in global brain ischemia and may even be toxic, especially when given in high doses.

Pharmacological influences on cardiopulmonary arrest-related brain damage in the rat.

The aim of the present work was to evaluate the protective properties of the calcium-entry blocker nimodipine against brain damage induced by cardiopulmonary arrest in a rat model. We studied first the effect of nimodipine administered in a blind and randomized fashion and started 5 min after the restoration of spontaneous circulation. Our experiments showed no improvement of survival, and nimodipine did not improve the neurological outcome in the animals surviving after 7 days. We even observed a trend toward a decreased survival rate when higher doses of nimodipine were used. In order to evaluate whether the lack of protective effect of nimodipine might have been due to the fact that it was given too late, we administered nimodipine in the second series of experiments at the earliest feasible postischemic moment, i.e. at the start of the resuscitation attempts. However, this study also failed to show an improved outcome in nimodipine-treated animals; there was even a significantly decreased resuscitation rate. In order to exclude that a cerebroprotective effect was antagonized by deleterious effects of nimodipine on the cardiovascular system, which may be especially vulnerable after resuscitation, we also studied nimodipine in the 4-vessel occlusion model in the rat. Indeed, in contrast to the cardiopulmonary arrest model, cardiovascular depression does not occur in this model. In these experiments, we started the administration of nimodipine before the induction of global brain ischemia, used 2 different dosage regimens and provided prolonged drug administration after restoration of cerebral blood flow in order to create optimal circumstances for a cerebroprotective effect to be detected. These experiments, however, also failed to show any cerebroprotective effect of nimodipine. In this 4-vessel occlusion model, we also evaluated, as a control drug, 1,3-butanediol, an alternate substrate for brain metabolism during ischemia that has been shown to offer cerebral protection in this animal model. Our results could, however, not confirm this beneficial effect. We conclude that in the rat there is no cerebroprotective effect of the calcium-entry blocker nimodipine on global brain ischemia as present during cardiopulmonary arrest. On the contrary, we even observed adverse effects, especially when high doses are used and/or when the drug is given during resuscitation attempts.

Survival after out-of-hospital cardiac arrest in elderly patients. Belgian Cerebral Resuscitation Study Group.

STUDY OBJECTIVES: To study whether age of the cardiac arrest patient is related to prognostic factors and survival. STUDY DESIGN: Retrospective analysis of a prospective registration of cardiac arrest events in the mobile ICUs of seven participating hospitals. STUDY POPULATION: Two thousand seven hundred seventy-six out-of-hospital cardiac arrests in which advanced life support was initiated. Cardiac arrests with a precipitating event requiring specific therapeutic consequences and with specific prognosis were not included in the analysis (eg, trauma, exsanguination, drowning, sudden infant death syndrome). RESULTS: Neither resuscitation rate (23%) nor mortality caused by a neurologic reason (9%) was significantly different between age groups. Mortality after CPR of non-neurologic etiology was significantly higher in the elderly patient (younger than 40 years, 16%; 40 to 69 years, 19%; 70 to 79 years, 30%; 80 years or older, 34%; P less than .005) and had a negative effect on survival in resuscitated elderly patients (P less than .05). Elderly patients more frequently had a dependent lifestyle before the arrest (P less than .025), an arrest of cardiac origin (P less than .001), electromechanical dissociation as the type of cardiac arrest (P less than .025), and a shorter duration of advanced life support in unsuccessful resuscitation attempts (r = -.178, P less than .0001). CONCLUSION: Because survival two weeks after CPR was not significantly different between age groups, we suggest that decision making in CPR should not be based on age but on factors with better predictive power for outcome and quality of survival.

Plasma norepinephrine concentrations during resuscitation in the dog.

The objective of this study was to evaluate whether the adrenal glands contribute to the increase in plasma norepinephrine concentrations during cardiopulmonary resuscitation, by releasing norepinephrine and/or by secreting epinephrine that facilitates the release of norepinephrine from sympathetic nerve endings via stimulation of presynaptic beta receptors. The experiments were performed in adrenalectomized and in sham-operated dogs. In adrenalectomized dogs the increase in plasma norepinephrine concentrations during cardiopulmonary arrest and basic life support (BLS) was markedly smaller than in sham-operated dogs. Intravenous infusion of physiologic doses of epinephrine during BLS in adrenalectomized animals did not influence the plasma norepinephrine concentrations. These data indicate that, as suggested by others, the marked increase in plasma norepinephrine concentrations during BLS in dogs is mainly of adrenomedullary origin. They also suggest that presynaptic facilitation of norepinephrine release by epinephrine is not important, but further experiments using higher doses of epinephrine are necessary.

Nimodipine decreases resuscitability in a cardiopulmonary arrest model in the rat.

Although calcium has been implicated in ischemia-induced brain death or dysfunction, many animal studies do not show a beneficial effect of calcium-entry blockers given after resuscitation from a cardiopulmonary arrest (CPA). This may be due to the fact that treatment was started too late; we, therefore, evaluated the effect of the calcium-entry blocker nimodipine administered at the earliest feasible postischemic moment, i.e. at the start of the resuscitation attempts. In anesthetized Wistar rats, CPA was induced by an intra-cardiac injection of KCl, and maintained for 7 min by chest restriction. At the start of the resuscitation attempts, 50 rats were blindly and randomly assigned to intravenous treatment with either nimodipine (10 micrograms/kg over 2 min, followed by 1 micrograms/kg per min for 60 min; n = 25) or saline (n = 25). In the nimodipine group, significantly less rats could be resuscitated (11/25 versus 20/25) and the survival rate at the end of the 7 days evaluation period tended to be lower (5/25 versus 11/25). In the rats surviving after 7 days, there was no difference between both groups in incidence of seizures, neurological status and histological lesions in the hippocampus. It is concluded that nimodipine, in the dose tested and given during resuscitation in this rat model, has a detrimental effect on resuscitability and no beneficial effect on the neurological outcome in the surviving animals.

Plasma concentrations of epinephrine during CPR in the dog.

STUDY OBJECTIVE: The purpose of this study was to evaluate whether the marked increase in the plasma concentrations of epinephrine during cardiopulmonary arrest and basic life support (BLS) could be due in part to decreased distribution and/or elimination. DESIGN AND INTERVENTIONS: Dogs were randomly assigned to undergo adrenalectomy or sham-operation. Some adrenalectomized animals received an epinephrine infusion. MEASUREMENTS AND MAIN RESULTS: In the seven sham-operated dogs, the plasma epinephrine concentrations increased markedly during BLS as expected. In the seven adrenalectomized dogs receiving a constant infusion of epinephrine, cardiopulmonary arrest and BLS induced a three to sixfold increase in plasma epinephrine concentrations, with an increase in the mean plasma epinephrine concentrations (calculated from the area under the curve) of 1.21 +/- 0.12 ng/mL (P less than .05). In the seven adrenalectomized dogs receiving a constant epinephrine infusion but not subjected to cardiopulmonary arrest, the plasma epinephrine concentrations remained stable. Finally, in the seven adrenalectomized dogs not receiving an epinephrine infusion, the mean plasma epinephrine concentrations during BLS (calculated from the area under the curve) increased only by 0.05 +/- 0.04 ng/mL, significantly less than in adrenalectomized dogs receiving an epinephrine infusion (P less than .01). CONCLUSION: The increase in plasma epinephrine concentrations during cardiopulmonary arrest and BLS is due in part to an altered disposition of epinephrine.

Nimodipine has no beneficial effect on neurological outcome in a cardiopulmonary arrest model in the rat.

Brain damage after resuscitation from cardiac arrest is believed to be related to calcium influx in ischaemic neurons and to postischaemic calcium-dependent vasospasm. We therefore evaluated the potentially protective effects of the calcium-entry blocker nimodipine in a cardiopulmonary arrest model in the rat. Male Wistar rats were anaesthetized with ketamine (group I) or hexobarbital (group II) and subjected to a KCl-induced cardiac arrest during 7 min (group I) or 12 min (group II). Five minutes after resuscitation, the rats were treated intravenously in a randomized and blind fashion. Group I received either saline or 1 microgram.kg-1.min-1 or 5 micrograms.kg-1.min-1 of nimodipine and group II either saline or 1 microgram.kg-1.min-1 of nimodipine. Survival, occurrence of seizures and neurological status were assessed daily during 7 days after resuscitation. On day 7, the brains of the surviving rats were perfusion-fixed and a histopathological evaluation of the hippocampus was performed. Nimodipine, in the doses tested, had no beneficial influence on the 7 day survival rate, nor on the occurrence of seizures and the neurological and histopathological scores in the rats surviving after 7 days. With the highest dose of nimodipine, there was even a trend towards a decrease of the survival rate, probably related to the drug's hypotensive effect. Therefore, our data do not show a protective effect of nimodipine after cardiac arrest.

Neurological damage in a cardiopulmonary arrest model in the rat.

In view of the interest in cerebral protection in the framework of cardiopulmonary arrest (CPA), we assessed the neurological damage in a CPA model in the rat. CPA was induced in anesthetized Wistar rats by discontinuation of the jet ventilation and intracardiac injection of KCl. The animals were resuscitated after a CPA of either 7 min, 10.5 min, or 14 min. Six rats were used as nonischemic controls. All nonischemic rats survived, whereas in the resuscitated rats the 7-day survival rate decreased with increasing CPA duration. In the resuscitated rats, the neurological score was worse than in the control rats, and the score after 10.5-min CPA was worse than after 7-min CPA. Seizures were observed in 68% of resuscitated rats. Histopathological evaluation revealed moderate but selective neuronal necrosis in the hippocampus of all ischemic rats, and no cortical necrosis. However, neither the occurrence of seizures nor the extent of neuronal necrosis was related to the CPA duration. We conclude that in this model survival rate, neurological score, occurrence of seizures, and histopathological assessment can be used to evaluate neurological damage, although the contribution of other organ failure to these effects cannot be excluded.