Should semi-automatic defibrillators be used by emergency medical technicians in Belgium? The Belgian Cerebral Resuscitation Study Group.

Early external defibrillation is the single most effective intervention in patients with out-of-hospital cardiac arrest. Literature data indicate that instructing emergency medical technicians (EMTs) to use defibrillators is beneficial, provided the local emergency medical system is well organized. We tried to estimate the potential benefit of early defibrillation in some centres in Belgium by retrospectively analyzing the data from the Belgian Cardio-Pulmonary-Cerebral Resuscitation Registry collected between 1983 and 1987 in Belgian centres with a Mobile Intensive Care Unit (MICU). The data show that 2310 out of 3371 patients (69%) were first attended by the EMTs; on subsequent arrival of the MICU-teams, 584 of these 2310 patients i.e. 17% of the whole study population, presented with ventricular fibrillation. Analysis of estimated time factors in these 2310 patients revealed that the median time interval between collapse and start of resuscitation by EMTs was 8 min; the median time interval between collapse and start of MICU-resuscitation attempts was 16 min. The duration of EMT-resuscitation before MICU-arrival was probably more than 5 min and 10 min in 58% and 23% of the cases respectively. It is concluded that EMTs can be expected to reach a substantial number of ventricular fibrillation victims within a few minutes after the collapse and many minutes before arrival of the MICU. Therefore, training of EMTs in the use of semi-automatic defibrillators seems worthwhile in MICU-served regions in Belgium.

Identification of the hepatitis B virus factor that inhibits expression of the beta interferon gene.

The identity of the trans-acting factor encoded by the 1,828-bp BamHI DNA fragment of hepatitis B virus (HBV) that suppresses the transcription of the human beta interferon gene was investigated. Each complete and partial open reading frame (ORF) present within the 1,828-bp BamHI HBV DNA fragment was cloned into a simian virus 40 expression vector, and the resulting gene products were assayed for their ability to inhibit the activity of the regulatory DNA region that governs the expression of the beta interferon gene. Only the proteins encoded by the C ORF inhibited the activity of the beta interferon regulatory DNA region; putative proteins encoded by the partial X, P, and S ORFs present in the 1,828-bp BamHI HBV DNA fragment had no effect. A plasmid encoding only the native HBV core antigen, but not one coding for a truncated core antigen, possessed this inhibitory activity. The inhibition by the core antigen was specific for the regulatory elements of the beta interferon gene; none of a variety of viral transcriptional elements was inhibited.

An internal domain of the hepatitis B virus X antigen is necessary for transactivating activity.

A number of deletion mutants of the hepatitis B viral X antigen had been constructed and assayed for their ability to transactivate heterologous viral regulatory elements. Neither the N-terminal nor the C-terminal amino acid residues were required for transactivating activity. Transactivating activity that resided within amino acid residues 32 to 148 of the X antigen did not show any target DNA sequence or cell line specificity.

Influence of time intervals on outcome of CPR. The Cerebral Resuscitation Study Group.

Time is an essential element for successful CPR. Two time factors are particularly important: the duration of complete CA and the time to advanced life support. According to a registration protocol, these time factors, together with other variables and outcome were recorded in 3083 CA cases, treated by the NICU teams of 7 major Belgian hospitals. The mean duration of complete CA is 10.3 min for CPR failure (79%); 5.3 min for initial CPR success (21%); 3.4 min for long-term CPCR success (7%). The mean time to ALS is 19.7 min for CPR failure; 14.6 min for initial CPR success: 12.7 min for long-term CPCR success. Both duration of CA and time to ALS are independently related to outcome; the mean duration of BLS is less than 10 min and not significantly related to outcome. Response time of BLS and ALS are increasingly important in their 'rapid response' failure zone (time to ALS more than 8 min, time to BLS more than 4 min). The tiered MICU system, with nurse paramedics before physicians, has equal time to ALS and comparable outcome results to the non-tiered MICU system. According to our present experience, the following time goals are proposed for Belgian EMS-MICU systems: duration of CA less or equal to 4 min (introduction time less than or equal to 1 min and response time of BLS less than or equal to 3 min) and time to ALS less than or equal to 9 min. These time goals stand, in Belgium for perfection of public training in CPR and for spreading of a higher number of MICU teams countrywide.

Relevance and significance of pre-CPR conditions in cardio-pulmonary-cerebral resuscitation. A graphic analysis by means of Spectramap. The Cerebral Resuscitation Study Group.

The effects of pre-arrest conditions on success rates of CPCR have been studied in 4501 circulatory arrests that have been recorded by the Belgian CPCR-Registry from 1983 to 1987. A graphical technique called Spectramap has been used for the simultaneous perception of clinical relevance and statistical significance. The success of CPCR is determined to a large extent by pre-arrest conditions. Arrests occurring inside hospitals possess a far better prognosis than those observed outside. (Overall success rate inside hospitals is 18% vs. 7% outside). Site of arrest, time to call, time to CPR, and bystander intervention appear to be relevant and significant conditions outside the hospital. Age, underlying disease and degree of disability are shown to be relevant and significant inside hospitals. The Belgian CPCR-Registry, combined with Spectramap, also allows assessment of the efficiency of emergency services and the efficacy of life supporting treatments. This article describes the graphical method of Spectramap and its application to the Belgian CPCR-Registry.

Influence of pre-CPR conditions on EMS response times in circulatory arrest. The Cerebral Resuscitation Study Group.

Several time intervals, with important influence on the outcome of CA and CPR, are determined by the local EMS-MICU characteristics: time to introduction in the EMS, response time of BLS, duration of BLS before ALS. These time factors have been studied in 2779 out-of-hospital CA cases, treated by the MICU in teams of 7 major Belgian hospitals. The analysis compares the time intervals in the following pre-CPR conditions: the age of the patient; the previous health status of the patient; the disease underlying the CA; the site where CA occurs; the witnessing of the CA; the type of CA; the MICU center, responding to the CA. The mean introduction time is 4.6 min, the mean response time of BLS is 5.1 min, the mean duration of BLS before ALS is 11 min. Introduction in EMS should be improved in CA due to intoxication, drowning, SIDS and respiratory disease, and overall when CA occurs at home.