Contaminated heparin and outcomes after cardiac surgery: a retrospective propensity-matched cohort study.

BACKGROUND During 2007 and 2008 it is likely that millions of patients in the US received heparin contaminated (CH) with oversulfated chondroitin sulfate, which was associated with anaphylactoid reactions. We tested the hypothesis that CH was associated with serious morbidity, mortality, intensive care unit (ICU) stay and heparin-induced thrombocytopenia following adult cardiac surgery. METHODS AND FINDINGS We conducted a single center, retrospective, propensity-matched cohort study during the period of CH and the equivalent time frame in the three preceding or the two following years. Perioperative data were obtained from the institutional record of the Society of Thoracic Surgeons National Database, for which the data collection is prospective, standardized and performed by independent investigators. After matching, logistic regression was performed to evaluate the independent effect of CH on the composite adverse outcome (myocardial infarction, stroke, pneumonia, dialysis, cardiac arrest) and on mortality. Cox regression was used to determine the association between CH and ICU length of stay. The 1∶5 matched groups included 220 patients potentially exposed to CH and 918 controls. There were more adverse outcomes in the exposed cohort (20.9% versus 12.0%; difference  =  8.9%; 95% CI 3.6% to 15.1%, P < 0.001) with an odds ratio for CH of 2.0 (95% CI, 1.4 to 3.0, P < 0.001). In the exposed group there was a non-significant increase in mortality (5.9% versus 3.5%, difference = 2.4%; 95% CI, -0.4 to 3.5%, P  =  0.1), the median ICU stay was longer by 14.1 hours (interquartile range -26.6 to 79.8, S = 3299, P = 0.0004) with an estimated hazard ratio for CH of 1.2 (95% CI, 1.0 to 1.4, P = 0.04). There was no difference in nadir platelet counts between cohorts. CONCLUSIONS The results from this single center study suggest the possibility that contaminated heparin might have contributed to serious morbidity following cardiac surgery.

CPR training in households of patients with chest pain

The objectives of this study are to (1) quantify prior cardiopulmonary resuscitation (CPR) training in households of patients presenting to the Emergency Department (ED) with or without chest pain or ischaemic heart disease (IHD); (2) evaluate the willingness of household members to undertake CPR training; and (3) identify potential barriers to the learning and provision of bystander CPR. A cross-sectional study was conducted by surveying patients presenting to the ED of a metropolitan teaching hospital over a 6-month period. Two in five households of patients presenting with chest pain or IHD had prior training in CPR. This was no higher than for households of patients presenting without chest pain or IHD. Just under two in three households of patients presenting with chest pain or IHD were willing to participate in future CPR classes. Potential barriers to learning CPR included lack of information on CPR classes, perceived lack of intellectual and/or physical capability to learn CPR and concern about causing anxiety in the person at risk of cardiac arrest. Potential barriers to CPR provision included an unknown cardiac arrest victim and fear of infection. The ED provides an opportunity for increasing family and community capacity for bystander intervention through referral to appropriate training.

Methods and preliminary results for a data linkage project to determine long-term survival after intensive care unit admission

Aims: To describe a local data linkage project to match hospital data with the Australian Institute of Health and Welfare (AIHW) National Death Index (NDI) to assess longterm outcomes of intensive care unit patients. Methods: Data were obtained from hospital intensive care and cardiac surgery databases on all patients aged 18 years and over admitted to either of two intensive care units at a tertiary-referral hospital between 1 January 1994 and 31 December 2005. Date of death was obtained from the AIHW NDI by probabilistic software matching, in addition to manual checking through hospital databases and other sources. Survival was calculated from time of ICU admission, with a censoring date of 14 February 2007. Data for patients with multiple hospital admissions requiring intensive care were analysed only from the first admission. Summary and descriptive statistics were used for preliminary data analysis. Kaplan-Meier survival analysis was used to analyse factors determining long-term survival. Results: During the study period, 21 415 unique patients had 22 552 hospital admissions that included an ICU admission; 19 058 surgical procedures were performed with a total of 20 092 ICU admissions. There were 4936 deaths. Median follow-up was 6.2 years, totalling 134 203 patient years. The casemix was predominantly cardiac surgery (80%), followed by cardiac medical (6%), and other medical (4%). The unadjusted survival at 1, 5 and 10 years was 97%, 84% and 70%, respectively. The 1-year survival ranged from 97% for cardiac surgery to 36% for cardiac arrest. An APACHE II score was available for 16 877 patients. In those discharged alive from hospital, the 1, 5 and 10-year survival varied with discharge location. Conclusions: ICU-based linkage projects are feasible to determine long-term outcomes of ICU patients

The hypothermic patient

Concepts used in this chapter include: Thermoregulation:- Thermoregulation refers to the body’s sophisticated, multi-system regulation of core body temperature. This hierarchical system extends from highly thermo-sensitive neurons in the preoptic region of the brain proximate to the rostral hypothalamus, down to the brain stem and spinal cord. Coupled with receptors in the skin and spine, both central and peripheral information on body temperature is integrated to inform and activate the homeostatic mechanisms which maintain our core temperature at 37oC.1 Body heat is lost through the skin, via respiration and excretions. The skin is perhaps the most important organ in regulating heat loss. Hyporthermia:- Hypothermia is defined as core body temperature less than 350C and is the result of imbalance between the body’s heat production and heat loss mechanisms. Hypothermia may be accidental, or induced for clinical benefit i.e: neurological protection (therapeutic hypothermia). External environmental conditions are the most common cause of accidental hypothermia, but not the only causes of hypothermia in humans. Other causes include metabolic imbalance; trauma; neurological and infectious disease; and exposure to toxins such as organophosphates. Therapeutic Hypothermia:- In some circumstances, hypothermia can be induced to protect neurological functioning as a result of the associated decrease in cerebral metabolism and energy consumption. Reduction in the extent of degenerative processes associated with periods of ischaemia such as excitotoxic cascade; apoptotic and necrotic cell death; microglial activation; oxidative stress and inflammation associated with ischaemia are averted or minimised.2 Mild hypothermia is the only effective treatment confirmed clinically for improving the neurological outcomes of patient’s comatose following cardiac arrest.3

Measurements of adequacy of anesthesia and level of consciousness during surgery and intensive care

The adequacy of anesthesia has been studied since the introduction of balanced general anesthesia. Commercial monitors based on electroencephalographic (EEG) signal analysis have been available for monitoring the hypnotic component of anesthesia from the beginning of the 1990s. Monitors measuring the depth of anesthesia assess the cortical function of the brain, and have gained acceptance during surgical anesthesia with most of the anesthetic agents used. However, due to frequent artifacts, they are considered unsuitable for monitoring consciousness in intensive care patients. The assessment of analgesia is one of the cornerstones of general anesthesia. Prolonged surgical stress may lead to increased morbidity and delayed postoperative recovery. However, no validated monitoring method is currently available for evaluating analgesia during general anesthesia. Awareness during anesthesia is caused by an inadequate level of hypnosis. This rare but severe complication of general anesthesia may lead to marked emotional stress and possibly posttraumatic stress disorder. In the present series of studies, the incidence of awareness and recall during outpatient anesthesia was evaluated and compared with that of in inpatient anesthesia. A total of 1500 outpatients and 2343 inpatients underwent a structured interview. Clear intraoperative recollections were rare the incidence being 0.07% in outpatients and 0.13% in inpatients. No significant differences emerged between outpatients and inpatients. However, significantly smaller doses of sevoflurane were administered to outpatients with awareness than those without recollections (p<0.05). EEG artifacts in 16 brain-dead organ donors were evaluated during organ harvest surgery in a prospective, open, nonselective study. The source of the frontotemporal biosignals in brain-dead subjects was studied, and the resistance of bispectral index (BIS) and Entropy to the signal artifacts was compared. The hypothesis was that in brain-dead subjects, most of the biosignals recorded from the forehead would consist of artifacts. The original EEG was recorded and State Entropy (SE), Response Entropy (RE), and BIS were calculated and monitored during solid organ harvest. SE differed from zero (inactive EEG) in 28%, RE in 29%, and BIS in 68% of the total recording time (p<0.0001 for all). The median values during the operation were SE 0.0, RE 0.0, and BIS 3.0. In four of the 16 organ donors, EEG was not inactive, and unphysiologically distributed, nonreactive rhythmic theta activity was present in the original EEG signal. After the results from subjects with persistent residual EEG activity were excluded, SE, RE, and BIS differed from zero in 17%, 18%, and 62% of the recorded time, respectively (p<0.0001 for all). Due to various artifacts, the highest readings in all indices were recorded without neuromuscular blockade. The main sources of artifacts were electrocauterization, electromyography (EMG), 50-Hz artifact, handling of the donor, ballistocardiography, and electrocardiography. In a prospective, randomized study of 26 patients, the ability of Surgical Stress Index (SSI) to differentiate patients with two clinically different analgesic levels during shoulder surgery was evaluated. SSI values were lower in patients with an interscalene brachial plexus block than in patients without an additional plexus block. In all patients, anesthesia was maintained with desflurane, the concentration of which was targeted to maintain SE at 50. Increased blood pressure or heart rate (HR), movement, and coughing were considered signs of intraoperative nociception and treated with alfentanil. Photoplethysmographic waveforms were collected from the contralateral arm to the operated side, and SSI was calculated offline. Two minutes after skin incision, SSI was not increased in the brachial plexus block group and was lower (38 ± 13) than in the control group (58 ± 13, p<0.005). Among the controls, one minute prior to alfentanil administration, SSI value was higher than during periods of adequate antinociception, 59 ± 11 vs. 39 ± 12 (p<0.01). The total cumulative need for alfentanil was higher in controls (2.7 ± 1.2 mg) than in the brachial plexus block group (1.6 ± 0.5 mg, p=0.008). Tetanic stimulation to the ulnar region of the hand increased SSI significantly only among patients with a brachial plexus block not covering the site of stimulation. Prognostic value of EEG-derived indices was evaluated and compared with Transcranial Doppler Ultrasonography (TCD), serum neuron-specific enolase (NSE) and S-100B after cardiac arrest. Thirty patients resuscitated from out-of-hospital arrest and treated with induced mild hypothermia for 24 h were included. Original EEG signal was recorded, and burst suppression ratio (BSR), RE, SE, and wavelet subband entropy (WSE) were calculated. Neurological outcome during the six-month period after arrest was assessed with the Glasgow-Pittsburgh Cerebral Performance Categories (CPC). Twenty patients had a CPC of 1-2, one patient had a CPC of 3, and nine patients died (CPC 5). BSR, RE, and SE differed between good (CPC 1-2) and poor (CPC 3-5) outcome groups (p=0.011, p=0.011, p=0.008, respectively) during the first 24 h after arrest. WSE was borderline higher in the good outcome group between 24 and 48 h after arrest (p=0.050). All patients with status epilepticus died, and their WSE values were lower (p=0.022). S-100B was lower in the good outcome group upon arrival at the intensive care unit (p=0.010). After hypothermia treatment, NSE and S-100B values were lower (p=0.002 for both) in the good outcome group. The pulsatile index was also lower in the good outcome group (p=0.004). In conclusion, the incidence of awareness in outpatient anesthesia did not differ from that in inpatient anesthesia. Outpatients are not at increased risk for intraoperative awareness relative to inpatients undergoing general anesthesia. SE, RE, and BIS showed non-zero values that normally indicate cortical neuronal function, but were in these subjects mostly due to artifacts after clinical brain death diagnosis. Entropy was more resistant to artifacts than BIS. During general anesthesia and surgery, SSI values were lower in patients with interscalene brachial plexus block covering the sites of nociceptive stimuli. In detecting nociceptive stimuli, SSI performed better than HR, blood pressure, or RE. BSR, RE, and SE differed between the good and poor neurological outcome groups during the first 24 h after cardiac arrest, and they may be an aid in differentiating patients with good neurological outcomes from those with poor outcomes after out-of-hospital cardiac arrest.

Maallikon suorittama defibrillaatio sydänpysähdyspotilaan hoitoketjussa

Sudden cardiac arrest (CA) is one of the leading causes of death in Europe. It has been estimated that about 40 % of CA victims have ventricular fibrillation (VF) at the time of the first heart rhythm analysis. The treatment for VF is immediate cardiopulmonary resuscitation (CPR) and rapid defibrillation. The automated external defibrillator (AED) and the concept of public access defibrillation (PAD) may be a key to shortening defibrillation delays. Recent studies have shown that PAD programs are associated with high survival rates from VF when devices have been placed in certain risk sites and used by trained laypersons. Today many public places are equipped with AEDs. The purpose of this study was to find new ways of utilizing layperson defibrillation and promote the concept of public access defibrillation (PAD). The study explored the use of AEDs by non-medical first responders in Finland and cabin crew on board a commercial aircraft. A simulated study was performed to explore the role of dispatcher assistance in layperson CPR and defibrillation. A 15-year follow-up study of 59 one-year survivors after successful out-of-hospital resuscitation was performed to evaluate the long-term quality of life of the CA patients. Although there are many AEDs in use by non-medical first responders in Finland, the results of the study showed that there are large variations between individual first response units. This is considered to be caused by the lack of national standards and regulations that would define a full integration of first-responder programmes into the Emergency Medical Services system. The goal of rapid defibrillation in five minutes after the onset of CA is difficult to achieve in Finland due to sparse population and long distances. Local PAD programs may shorten the defibrillation delays. Dispatcher assistance in defibrillation by a layperson not trained to use an AED seems feasible and does not compromise the performance of CPR. In a simulated study, the quality of mouth-to-mouth ventilation performed by laypersons was found to be better after CPR training compared with performance with dispatcher assistance before training. Training was not found to have an influence on the quality of compressions or defibrillation compared with dispatcher assistance of untrained laypersons. The target groups for CPR and defibrillation training need further evaluation. The placements of the AEDs in public areas should be known by the emergency response center and the location should be marked with an international sign. The finding that once a good neurological outcome after CA is achieved, it can be maintained for more than 10 years, encourages further efforts to improve the survival of CA patients.

Treatment of illicit opioid and γ-hydroxybutyrate overdose by Helsinki emergency medical services

Aims: To examine the characteristics, incidence, treatment and outcome of presumed opioid, γ-hydroxybutyrate (GHB) and γ-butyrolactone (GBL) overdoses involving users of illicit drugs in Helsinki. GHB/GBL were included in this study, despite not being opioids, due to the relative ease with which they can cause potentially fatal respiratory depression. The incidence and time interval of recurrent opioid toxicity after prehospital administration of naloxone, an opioid antagonist, was studied in presumed heroin overdose patients. Naloxone has been reported to have many adverse effects and the effects of naloxone administered during an opioid overdose on the cardiovascular system and catecholamine levels in piglets were studied. Materials and methods: Patients included in these published retrospective studies were from the following time periods: Study I: 1995-2002, II: 1997-2000, III: 1995-2000, V: 2006-2007. Presumed opioid overdose patients were examined in studies I, II and III. GHB/GBL overdoses among injecting drug users was examined in study V. Recurrent opioid toxicity after prehospital naloxone administration in heroin overdose patients was examined in study III. The effects of naloxone (80 μg/kg i.v.) on the cardiovascular system and catecholamine levels administered during morphine overdose (8mg/kg i.v.) and under propofol anesthesia with spontaneous breathing were studied in eight piglets (IV). In this thesis, previously unpublished data on the incidence of opioid overdose between 2001-2007 and comparison of the characteristics of buprenorphine and heroin overdose patients encountered in 1995-2005 are also included. Results: Helsinki Emergency Medical Service (EMS) ambulances were dispatched annually to 34,153- 45,118 calls from 1995 to 2007. Of them, 7-8% were coded as intoxications or overdoses. During this time, 436 patients were treated by the EMS for presumed opioid overdose. The peak incidence of opioid overdoses was in the year 2000 (113 cases), after which they declined to 6-26 cases annually. The annual incidence of buprenorphine related overdoses increased from 4 (4% of opioid overdoses) in the year 2000 to 8 (30% of opioid overdoses) in 2007. The annual number of GHB related overdose patients treated by Helsinki EMS increased from 21 to 73 between 2004-2007. There appeared to be a peak in the incidence of both GHB/GBL and opioid related overdoses on Saturdays. Characteristics of opioid overdose patients The median age of opioid overdose patients was 28 years (22;33, 25- and 75-percentiles), and 84% were male. Buprenorphine overdose patients had more polydrug, such as alcohol and/or benzodiazepines, use in comparison with heroin overdose patients, 70% versus 33%, respectively. Severe respiratory depression was reported less often with buprenorphine overdoses compared to heroin overdoses, in 67.0% versus 85.4%, respectively. Outcome of heroin overdose patients with cardiac arrest Ninety four patients suffered cardiac arrest due to acute drug poisoning/overdose and were thus considered for resuscitation. Resuscitation was attempted in 72 cases. Cardiac arrest was caused by heroin overdose for 19 patients of which three (16%) were discharged alive. Other agents also induced cardiac arrest in 53 patients, of which six (11%) were discharged alive. The arrest was either EMS witnessed or occurring after the emergency call for all survivors of heroin induced cardiac arrest. Characteristics of GHB/GBL overdose patients The records of 100 GHB/GBL related overdose patients from 2006-2007 were retrieved. The median age of GHB/GBL overdose patients encountered on weekend nights was 24 years (22;27, 25- and 75-percentiles) and 49% were male. Polydrug use was reported in 62-80% of the cases. Thirty nine patients were encountered on Friday-Saturday or Saturday-Sunday night between 11 pm-6 am. The remaining sixty one patients were outside this time frame. There was a statistically significant difference between these two groups in history of chronic injecting drug use (33% vs. 59%, respectively, p=0.012). Recurrent heroin toxicity after prehospital naloxone administration Study III included 145 presumed heroin overdose patients. After prehospital care, 84 patients refused further care and were not transported to an Emergency Department (ED). Seventy one (85%) of them were administered naloxone by the EMS. During a 12-h follow up period, none of these patients developed severe recurrent opioid toxicity. The remaining 61 patients were transported to an ED. Prior to transportation, 52 (85%) patients were administered naloxone by the EMS. Fifteen of them were administered naloxone also in the ED and recurrent opioid toxicity was evident either on arrival at the ED or shortly thereafter. Prehospital naloxone was administered either intravenously, intramuscularly (i.m.) or subcutaneously (s.c.). There was a tendency for more frequent recurrent heroin toxicity among the patients with only intravenous administration of prehospital naloxone (13/36) compared with the patients with intramuscular or subcutaneous prehospital naloxone (2/16), p=0.106. The effects of naloxone on the cardiovascular system and catecholamine levels in piglets The administration of morphine to piglets resulted in an obvious respiratory depression, which was reversed by naloxone. Two severely hypoxemic piglets developed cardiac arrest after naloxone administration. In the other six animals, the administration of naloxone did not provoke arrhythmias, cardiac ischemia or visible evidence of pulmonary edema. There was a statistically significant (p=0.012) increase in norepinephrine levels after morphine administration and before naloxone administration: from 1.9 (1.3-2.3) ng/ml at baseline, to 31.7 (8.3-83.0) ng/ml (median, 25 and 75 percentiles parentheses) after morphine administration. After the administration of naloxone, the catecholamine levels continued to increase in only one of the animals. Conclusions: The incidence of buprenorphine related overdoses increased during the study period, but was still lower in comparison to those involving heroin. Injecting drug users have also started to use GHB/GBL. While recreational drug users use GHB/GBL during weekend nights, a GHB/GBL overdose patient encounter during weekdays has a more probable history of injecting drug use. Patients with cardiac arrest after heroin overdose have a poor prognosis. It appears to be safe to leave heroin overdose patients on scene after prehospital treatment with naloxone. Although no statistically significant difference was observed, it seems prudent to administer part of the total naloxone dose s.c. or i.m. to reduce the risk of recurrent respiratory depression. If transported to an ED, an observation period of one to two hours after the last naloxone dose seems adequate. The treating physician must be vigilant, however, due to the high prevalence of polydrug use and high morbidity after non fatal heroin overdose. Furthermore, care should be taken regarding possible chronic disorders and drug rehabilitation should be addressed. In the experimental animal study, two animals developed cardiac arrest after receiving naloxone while in hypoxemia and bradycardia. Further studies are required to assess the effect of naloxone during opioid-induced hypercapnia and hypoxemia in animals addicted to opioids.

New signal processing algorithms for automated external defibrillators

[ES]La fibrilación ventricular (VF) es el primer ritmo registrado en el 40\,\% de las muertes súbitas por paro cardiorrespiratorio extrahospitalario (PCRE). El único tratamiento eficaz para la FV es la desfibrilación mediante una descarga eléctrica. Fuera del hospital, la descarga se administra mediante un desfibrilador externo automático (DEA), que previamente analiza el electrocardiograma (ECG) del paciente y comprueba si presenta un ritmo desfibrilable. La supervivencia en un caso de PCRE depende fundamentalmente de dos factores: la desfibrilación temprana y la resucitación cardiopulmonar (RCP) temprana, que prolonga la FV y por lo tanto la oportunidad de desfibrilación. Para un correcto análisis del ritmo cardiaco es necesario interrumpir la RCP, ya que, debido a las compresiones torácicas, la RCP introduce artefactos en el ECG. Desafortunadamente, la interrupción de la RCP afecta negativamente al éxito en la desfibrilación. En 2003 se aprobó el uso del DEA en pacientes entre 1 y 8 años. Los DEA, que originalmente se diseñaron para pacientes adultos, deben discriminar de forma precisa las arritmias pediátricas para que su uso en niños sea seguro. Varios DEAs se han adaptado para uso pediátrico, bien demostrando la precisión de los algoritmos para adultos con arritmias pediátricas, o bien mediante algoritmos específicos para arritmias pediátricas. Esta tesis presenta un nuevo algoritmo DEA diseñado conjuntamente para pacientes adultos y pediátricos. El algoritmo se ha probado exhaustivamente en bases de datos acordes a los requisitos de la American Heart Association (AHA), y en registros de resucitación con y sin artefacto RCP. El trabajo comenzó con una larga fase experimental en la que se recopilaron y clasificaron retrospectivamente un total de 1090 ritmos pediátricos. Además, se revisó una base de arritmias de adultos y se añadieron 928 nuevos ritmos de adultos. La base de datos final contiene 2782 registros, 1270 se usaron para diseñar el algoritmo y 1512 para validarlo. A continuación, se diseñó un nuevo algoritmo DEA compuesto de cuatro subalgoritmos. Estos subalgoritmos están basados en un conjunto de nuevos parámetros para la detección de arritmias, calculados en diversos dominios de la señal, como el tiempo, la frecuencia, la pendiente o la función de autocorrelación. El algoritmo cumple las exigencias de la AHA para la detección de ritmos desfibrilables y no-desfibrilables tanto en pacientes adultos como en pediátricos. El trabajo concluyó con el análisis del comportamiento del algoritmo con episodios reales de resucitación. En los ritmos que no contenían artefacto RCP se cumplieron las exigencias de la AHA. Posteriormente, se estudió la precisión del algoritmo durante las compresiones torácicas, antes y después de filtrar el artefacto RCP. Para suprimir el artefacto se utilizó un nuevo método desarrollado a lo largo de la tesis. Los ritmos desfibrilables se detectaron de forma precisa tras el filtrado, los no-desfibrilables sin embargo no.

Rhythm Analysis during Cardiopulmonary Resuscitation: Past, Present, and Future

Survival from out-of-hospital cardiac arrest depends largely on two factors: early cardiopulmonary resuscitation (CPR) and early defibrillation. CPR must be interrupted for a reliable automated rhythm analysis because chest compressions induce artifacts in the ECG. Unfortunately, interrupting CPR adversely affects survival. In the last twenty years, research has been focused on designing methods for analysis of ECG during chest compressions. Most approaches are based either on adaptive filters to remove the CPR artifact or on robust algorithms which directly diagnose the corrupted ECG. In general, all the methods report low specificity values when tested on short ECG segments, but how to evaluate the real impact on CPR delivery of continuous rhythm analysis during CPR is still unknown. Recently, researchers have proposed a new methodology to measure this impact. Moreover, new strategies for fast rhythm analysis during ventilation pauses or high-specificity algorithms have been reported. Our objective is to present a thorough review of the field as the starting point for these late developments and to underline the open questions and future lines of research to be explored in the following years.

Bihotz-biriketako berpizte masajeak EKG-an eta bular-inpedantzian eragindako interferentziaren azterketa

[EU]Proiektu honetan bihotz-biriketako berpizte masajearen bular-sakadek elektrokardiograman eta bular-inpedantziaren seinaleetan eragindako interferentziaren azterketa egiten da. Helburu nagusia bi interferentzia hauen arteko erlazioa aztertzea da, horretarako tresna garatuz. Erlazio hau definitzeak interferentziaren eragina txikitzeko modua aurkitzen lagunduko luke, eta honek berpizteko aukerak handituko lituzke. Proiektua gauzatzeko ospitalez kanpoko geldialdien erregistro multzo batetik abiatuta datu-base propioa garatu da ezarritako irizpide batzuk jarraituz. Datu-base berri hau 37 pazienteren 237 mozketak osatzen dute, 10 segundotako luzera minimoarekin non pazienteek asistolia bitarteko kanpoko bular masajea jasotzen duten. Bestalde, interferentzia ezaugarritzeko interfaze grafiko bat garatu da, elektrokardiograma eta bular-inpedantziaren seinaleak denboran eta maiztasunean erakutsi eta hauen parametro esanguratsuak automatikoki zein eskuz ateratzeko aukera ematen duena. Parametroak seinaleen sakada bakoitzeko maximo eta minimoak, beraien kokapenak eta oinarrizko maiztasuna, bere harmonikoak eta hauen anplitudeak dira. Tresna hau erabiliz aipatutako datu-baseko episodioen prozesaketa egin da. Bukatzeko, lortutako emaitzak tratatzeko bigarren interfaze grafiko bat garatu da, non emaitzen banaketa estatistikoa eta hauen arteko erlazio lineala aztertzen diren. Proiektuaren ekarpen nagusia, beraz, bihotz-biriketako berpizte masajeak eragindako interferentzia aztertzeko tresna ahaltsuaren garapena da, jatorri desberdineko bestelako berpizte episodioak aztertzeko ere balio duena.

Plataforma de investigación en el ámbito de la resucitación cardio-pulmonar basada en un maniquí de entrenamiento sensorizado

[ES]Hoy en día las muertes por parada cardiorrespiratoria superan en número a otras más mediáticas como aquellas que se producen por incendios o en accidentes de tráfico, y sin embargo su repercusión es mucho menor. Este hecho debe ser motivo de preocupación ya que, con una correcta formación de la población en materia de resucitación cardíaca, muchas de estas muertes podrían ser evitadas. Con el objetivo de reducir estas estadísticas han surgido multitud de estudios y proyectos de investigación consistentes en tratar de mejorar las herramientas disponibles tanto para personal sanitario como no sanitario. En este marco se encuadra el proyecto presentado en este documento, consistente en la sensorización de un maniquí de entrenamiento para episodios de parada cardiorrespiratoria, el cual ofrecerá la posibilidad de analizar con detalle el artifact o interferencia generada por el rescatador sobre el paciente en el momento de efectuar la maniobra de resucitación, así como la interferencia causada por el contacto electrodo-piel. Paralelamente podrá ser utilizado como mero instrumento de entrenamiento para posibles situaciones reales. El porqué de la utilización de este tipo de maniquíes reside principalmente en la imposibilidad de emplear personas debido a las posibles lesiones torácicas que pueden ocurrir por las compresiones realizadas. Finalmente debe citarse el hecho de que no es imprescindible tener conocimientos médicos para poder aplicar las técnicas básicas de resucitación cardíaca, acción que incrementa las posibilidades de supervivencia de un paciente de manera excepcional, ya que cada minuto que pasa desde la parada cardiorrespiratoria la probabilidad de supervivencia disminuye en un porcentaje significativamente elevado. Tomando como base lo descrito hasta ahora, en este documento se detalla la solución técnica de la sensorización de un maniquí genérico para la adquisición de las señales de fuerza de compresión, aceleración sufrida por el pecho en tres ejes ortogonales, profundidad de compresión, impedancia entre los dos electrodos colocados sobre el pecho del paciente y señal electrocardiográfica emitida por el corazón; además, se incluye la posibilidad de inyectar una señal electrocardiográfica previamente grabada. La base de registros obtenida de estos ensayos podrá ser utilizada posteriormente para su análisis, ya que su similitud con señales extraídas en un caso real es máxima.

Bihotz biriketako berpiztea simulatzeko panpin baten kudeaketarako tresna

[EU]Lan honen helburua, sentsorizatutako panpina kontrolatzeko software bat garatzea da, bihotz biriketako berpiztearen inguruko ikerkuntza sustatzeko helburuarekin. Kontrol hau aurrera eramateko bihotz biriketako berpiztearen inguruko kalitate parametro garrantzitsuenak jasotzen dituzten sentsoreekin hornitutako panpina bat erabili da, softwarearen eta panpinaren sentsoreen arteko interfaze gisa NI-DAQ National Instruments-eko txartela erabili delarik. Eskema honi jarraituz, software honek eskaintzen dituen funtzionalitate garrantzitsuenak hurrengoak dira: panpinaren bihotza simulatuko duen elektrokardiograma seinale bat panpinara transferitzea, sentsoreetatik lortutako informazioa biltegiratzea eta denbora errealean bistaratzea eta aurretiaz grabatutako erregistroen erreprodukzioa. Software hau garatzearen arrazoi nagusiak, bihotz biriketako berpiztearen kalitatea hobetzea eta elektrodoen eta pazientearen azalaren arteko kontaktuak elektrokardiograman sortzen duen interferentzia ezaugarritzea dira, bihotz-geldiunea pairatzen duen pazientearen bizi-iraupena handituko duten tresnen garapena sustatuz. Izan ere, bihotz-heriotza da herrialde garatuenen lehen heriotza-arrazoia.

Dispositivos suprágloticos: una aproximación a su uso en el ámbito extrahospitalario

[Es]Introducción: El manejo óptimo de la vía aérea extrahospitalaria es todavía incierto. Los dispositivos supraglóticos y la intubación endotraqueal han sido utilizados en los últimos años por los servicios de emergencia, pero no se conoce aún si el uso de los nuevos dispositivos supraglóticos mejora la supervivencia. Objetivo: Determinar la supervivencia a corto plazo (igual o menor a 1 mes) entre los dispositivos supraglóticos y la intubación endotraqueal en la parada cardíaca extrahospitalaria. Metodología: Se realizó una revisión bibliográfica en las bases de datos de Cochrane, Pubmed, MEDES, Scopus, CINAHL, Science Direct e IBECS y una búsqueda manual en las revistas Emergencias, Prehospital Emergency Care y Annals Emergency Medicine de estudios comprendidos entre los años 2004- 2014 que comparasen la supervivencia en la parada cardíaca extrahospitalaria del adulto entre los dispositivos supraglóticos y la intubación endotraqueal. Resultados: Se identificaron 9 estudios elegibles: 2 revisiones sistemáticas (una con metaanálisis), 1 ensayo clínico aleatorizado y 6 estudios de cohortes. 6 de los estudios mostraron mejores resultados en la intubación endotraqueal, 2 en los que no hubo diferencias y uno de ellos mostró mejores resultados en los dispositivos supraglóticos. Conclusiones: La intubación endotraqueal proporciona mayor supervivencia que los dispositivos supraglóticos en la parada cardíaca extrahospitalaria en adultos. Los dispositivos supraglóticos deberían utilizarse por parte de personal con poca experiencia en el uso de la intubación endotraqueal o como alternativa a la intubación fallida o con dificultad.

Diseño y evaluación de métodos de supresión del artefacto causado en el ECG por las compresiones torácicas proporcionadas por el dispositivo mecánico LUCAS.

[Es]En este proyecto se analizan el diseño y la evaluación de dos métodos para la supresión de la interferencia generada por las compresiones torácicas proporcionadas por el dispositivo mecánico LUCAS, en el electrocardiograma (ECG) durante el masaje de resucitación cardiopulmonar. El objetivo es encontrar un método que elimine el artefacto generado en el ECG de una manera efectiva, que permita el diagnóstico fiable del ritmo cardiaco. Encontrar un método eficaz sería de gran ayuda para no tener que interrumpir el masaje de resucitación para el análisis correcto del ritmo cardiaco, lo que supondría un aumento en las probabilidades de resucitación. Para llevar a cabo el proyecto se ha generado una base de datos propia partiendo de registros de paradas cardiorrespiratorias extra-hospitalarias. Esta nueva base de datos contiene 410 cortes correspondientes a 86 pacientes, siendo todos los episodios de 30 segundos de duración y durante los cuales el paciente, recibe masaje cardiaco. Por otro lado, se ha desarrollado una interfaz gráfica para caracterizar los métodos de supresión del artefacto. Esta, muestra las señales del ECG, de impedancia torácica y del ECG tras eliminar el artefacto en tiempo. Mediante esta herramienta se han procesado los registros aplicando un filtro adaptativo y un filtro de coeficientes constantes. La evaluación de los métodos se ha realizado en base a la sensibilidad y especificidad del algoritmo de clasificación de ritmos con las señales ECG filtradas. La mayor aportación del proyecto, por tanto, es el desarrollo de una potente herramienta eficaz para evaluar métodos de supresión del artefacto causado en el ECG por las compresiones torácicas al realizar el masaje de resucitación cardiopulmonar, y su posterior diagnóstico. Un instrumento que puede ser implementado para analizar episodios de resucitación de cualquier tipo de procedencia y capaz de integrar nuevos métodos de supresión del artefacto.

Aireztapenen maiztasunaren neurketa bihotz biriketako berpiztean kapnografia erabiliz.

[EN]Hyperventilation, which is common both in-hospital and out-of-hospital cardiac arrest, decreases coronary and cerebral perfusion contributing to poorer survival rates in both animals and humans. Current resucitation guidelines recommend continuous monitoring of exhaled carbon dioxide (CO2) during cardiopulmonary resucitation (CPR) and emphasize good quality of CPR, including ventilations at 8-10 min1. Most of commercial monitors/de- brilators incorporate methods to compute the respiratory rate based on capnography since it shows uctuations caused by ventilations. Chest compressions may induce artifacts in this signal making the calculation of the respiratory rate di cult. Nevertheless, the accuracy of these methods during CPR has not been documented yet. The aim of this project is to analyze whether the capnogram is reliable to compute ventilation rate during CPR. A total of 91 episodes, 63 out-of-hospital cardiac arrest episodes ( rst database) and 28 in-hospital cardiac arrest episodes (second database) were used to develop an algorithm to detect ventilations in the capnogram, and the nal aim is to provide an accurate ventilation rate for feedback purposes during CPR. Two graphic user interfaces were developed to make the analysis easier and another two were adapted to carry out this project. The use of this interfaces facilitates the managment of the databases and the calculation of the algorithm accuracy. In the rst database, as gold standard every ventilation was marked by visual inspection of both the impedance, which shows uctuations with every ventilation, and the capnography signal. In the second database, volume of the respiratory ow signal was used as gold standard to mark ventilation instants since it is not a ected by chest compressions. The capnogram was preprocessed to remove high frequency noise, and the rst di erence was computed to de ne the onset of inspiration and expiration. Then, morphological features were extracted and a decission algorithm built based on the extracted features to detect ventilation instants. Finally, ventilation rate was calculated using the detected instants of ventilation. According to the results obtained in this project, the capnogram can be reliably used to give feedback ventilation rate, and therefore, on hyperventilation in a resucitation scenario.