Jouni Kurola

Arterial Blood Gas Tensions After Resuscitation From Out-of-hospital Cardiac Arrest: Associations With Long-term Neurologic Outcome*

ObjectivesOptimal oxygen and carbon dioxide levels during postcardiac arrest care are currently undefined and observational studies have suggested harm from hyperoxia exposure. We aimed to assess whether mean and time-weighted oxygen and carbon dioxide levels during the first 24 hours of postcardiac arrest care correlate with 12-month neurologic outcome. DesignProspective observational cohort study. SettingTwenty-one ICUs in Finland. PatientsOut-of-hospital cardiac arrest patients treated in ICUs in Finland between March 2010 and February 2011. InterventionsNone. Measurements and Main Results:Arterial blood PaO2 and PaCO2 during the first 24 hours from admission were divided into predefined categories from the lowest to the highest. Proportions of time spent in different categories and the mean PaO2 and PaCO2 values during the first 24 hours were included in separate multivariable regression models along with resuscitation factors. The cerebral performance category at 12 months was used as primary endpoint. A total of 409 patients with arterial blood gases analyzed at least once and with a complete set of resuscitation data were included. The average amount of PaO2 and PaCO2 measurements was eight per patient. The mean 24 hours PaCO2 level was an independent predictor of good outcome (odds ratio, 1.054; 95% CI, 1.006–1.104; p = 0.027) but the mean PaO2 value was not (odds ratio, 1.006; 95% CI, 0.998–1.014; p = 0.149). With multivariate regression analysis, time spent in the PaCO2 band higher than 45 mm Hg was associated with good outcome (odds ratio, 1.015; 95% CI, 1.002–1.029; p = 0.024, for each percentage point increase in time) but time spent in different oxygen categories were not. Conclusions:In this multicenter study, hypercapnia was associated with good 12-month outcome in patients resuscitated from out-of-hospital cardiac arrest. We were unable to verify any harm from hyperoxia exposure. Further trials should focus on whether moderate hypercapnia during postcardiac arrest care improves outcome.

Incidence of iatrogenic dyscarbia during mild therapeutic hypothermia after successful resuscitation from out-of-hospital cardiac arrest.

To investigate the incidence of iatrogenic dyscarbia in survivors of out-of-hospital cardiac arrest treated with induced mild hypothermia.We performed a retrospective cohort study of the ventilatory management based on blood gas analyses of patients resuscitated from prehospital cardiac arrest. In the pilot phase, we assessed the ventilatory management in the patients treated in one university hospital during a 4-year study period. Subsequently, a more recent (1-year) retrospective cohort of resuscitated patients from all five Finnish university hospitals concerning the first 48h after hospital admission was analyzed. Core temperatures and temperature corrected (or non-corrected) blood gas analysis results with focus on carbon dioxide tension were analyzed. In addition, a survey was performed to investigate the ventilatory strategies in all Finnish hospitals providing mild hypothermia for cardiac arrest victims.The pilot cohort suggested a high incidence of hypo- or hyper-carbia during hypothermia treatment. In the multicenter patient population of 122 patients contributing a total of 1627 measurements, the PaCO(2) distribution was as follows: less than 4 kPa in 148 samples out of 1627 (9%), 4-4.6 kPa in 404 (25%), 4.7-6 kPa in 887 (55%) and more than 6 kPa in 188 samples (12%). There was a significant difference in the incidence of hypercarbia between the hospitals (p<0.05).We conclude that normocarbia was achieved/maintained only in approximately 55% of the samples. The incidence of hypo- or hyper-carbia (dyscarbia) was high (45%). This may predispose for serious derangements in the cerebral perfusion of the resuscitated patient. These results call for vigilance in adjustment of the ventilatory management to meet the needs of the patients treated with mild hypothermia.

Treatment of Serious Calcium Channel Blocker Overdose With Levosimendan, a Calcium Sensitizer

Calcium channel blocker (CCB) overdose is often lethal. Conventional medical treatment includes i.v. calcium, high doses of catecholamines, insulin, and glucagon. A new inotropic drug, levosimendan, should be considered in severe CCB poisoning. Levosimendans pharmacologic features differ from other inotropic drugs. It is a calcium sensitizer and improves contraction without increasing intracytosolic calcium concentration. We describe two patients with serious CCB overdose. Despite intensive medical and mechanical cardiovascular support, both patients remained in shock. Hemodynamics gradually improved after administration of levosimendan.

A comparison of the laryngeal tube and bag-valve mask ventilation by emergency medical technicians: a feasibility study in anesthetized patients.

Airway management is of major importance in emergency care. The basic technique for all health care providers is bag-valve mask (BVM) ventilation, which requires skill and may be difficult to perform. Endotracheal intubation, which is the advanced method for securing the airway, is a demanding technique that has been shown to be associated with infrequent success, even when used by experienced paramedical personnel. Therefore, alternative airway devices have been sought. The use of the laryngeal tube (LT) by experienced anesthesia personnel had been studied in anesthetized patients and manikins in emergency medical training. We decided to evaluate the ability of inexperienced firefighter-emergency medical technician students (fire-EMT) to insert the LT or perform BVM in anesthetized patients. Thirty fire-EMTs randomly inserted the LT (n = 15) and performed 1 min of ventilation or used the BVM (n = 15). We found that all students successfully (100%) inserted the LT. Those who inserted the LT on the first attempt (73%) required 48.2 ± 14.7 s for the insertion. Both the LT and BVM provided adequate oxygenation and ventilation. In this study, we found that inexperienced fire-EMT students inserted LT and performed 1-min ventilation with a reasonable success rate and insertion time in anesthetized patients.

Regional variation and outcome of out-of-hospital cardiac arrest (ohca) in Finland – the Finnresusci study

BackgroundDespite the efforts of the modern Emergency Medical Service Systems (EMS), survival rates for sudden out-of-hospital cardiac arrest (OHCA) have been poor as approximately 10% of OHCA patients survive hospital discharge. Many aspects of OHCA have been studied, but few previous reports on OHCA have documented the variation between different sizes of study areas on a regional scale. The aim of this study was to report the incidence, outcomes and regional variation of OHCA in the Finnish population.MethodsFrom March 1st to August 31st, 2010, data on all OHCA patients in the southern, central and eastern parts of Finland was collected. Data collection was initiated via dispatch centres whenever there was a suspected OHCA case or if a patient developed OHCA before arriving at the hospital. The study area includes 49% of the Finnish population; they are served by eight dispatch centres, two university hospitals and six central hospitals.ResultsThe study period included 1042 cases of OHCA. Resuscitation was attempted on 671 patients (64.4%), an incidence of 51/100,000 inhabitants/year. The initial rhythm was shockable for 211 patients (31.4%). The survival rate at one-year post-OHCA was 13.4%. Of the witnessed OHCA events with a shockable rhythm of presumed cardiac origin (n=140), 64 patients (45.7%) were alive at hospital discharge and 47 (33.6%) were still living one year hence. Surviving until hospital admission was more likely if the OHCA occurred in an urban municipality (41.5%, p=0.001).ConclusionsThe results of this comprehensive regional study of OHCA in Finland seem comparable to those previously reported in other countries. The survival of witnessed OHCA events with shockable initial rhythms has improved in urban Finland in recent decades.

Secretoneurin is a novel prognostic cardiovascular biomarker associated with cardiomyocyte calcium handling.

BACKGROUND Secretoneurin (SN) levels are increased in patients with heart failure (HF), but whether SN provides prognostic information and influences cardiomyocyte function is unknown. OBJECTIVES This study sought to evaluate the merit of SN as a cardiovascular biomarker and assess effects of SN on cardiomyocyte Ca(2+) handling. METHODS We assessed the association between circulating SN levels and mortality in 2 patient cohorts and the functional properties of SN in experimental models. RESULTS In 143 patients hospitalized for acute HF, SN levels were closely associated with mortality (n = 66) during follow-up (median 776 days; hazard ratio [lnSN]: 4.63; 95% confidence interval: 1.93 to 11.11; p = 0.001 in multivariate analysis). SN reclassified patients to their correct risk strata on top of other predictors of mortality. In 155 patients with ventricular arrhythmia-induced cardiac arrest, SN levels were also associated with short-term mortality (n = 51; hazard ratio [lnSN]: 3.33; 95% confidence interval: 1.83 to 6.05; p < 0.001 in multivariate analysis). Perfusing hearts with SN yielded markedly increased myocardial levels and SN internalized into cardiomyocytes by endocytosis. Intracellularly, SN reduced Ca(2+)/calmodulin (CaM)-dependent protein kinase II δ (CaMKIIδ) activity via direct SN-CaM and SN-CaMKII binding and attenuated CaMKIIδ-dependent phosphorylation of the ryanodine receptor. SN also reduced sarcoplasmic reticulum Ca(2+) leak, augmented sarcoplasmic reticulum Ca(2+) content, increased the magnitude and kinetics of cardiomyocyte Ca(2+) transients and contractions, and attenuated Ca(2+) sparks and waves in HF cardiomyocytes. CONCLUSIONS SN provided incremental prognostic information to established risk indices in acute HF and ventricular arrhythmia-induced cardiac arrest.

Feasibility of a laryngeal tube for airway management during cardiac arrest by first responders

Airway management is of major importance in prehospital emergency care. Bag-valve mask (BVM) ventilation and endotracheal intubation (ETI) have been shown to be difficult, especially when caregivers are inexperienced. Alternative methods have been studied, and supraglottic devices have been shown to provide reasonable ease of placement and effective ventilation in manikin studies and anaesthetised patients. First responders (FR) are employed by many emergency medical services (EMS) to shorten initiation of emergency care, and they are trained to provide basic CPR including BVM and use of automated external defibrillators (AED) in case of out-of-hospital cardiac arrest (OCHA). The aim of this research was to study the feasibility of manikin-trained FRs using a laryngeal tube (LT) as a primary airway method during cardiac arrest. We trained 300 FRs to use a LT during OHCA. The FRs used a LT in 64 OHCA cases. The LT was correctly placed on the first attempt in 46/64 cases (71.9%) and on the second attempt in 13/64 cases (20.3%). Insertion was reported as being easy in 55/64 cases (85.9%). Median insertion time was 23.1s, with a range of 3-240s. We found that after manikin training, the FRs inserted the LT and performed adequate ventilation with a reasonable success rate and insertion time.

Early Activation of the Kynurenine Pathway Predicts Early Death and Long-term Outcome in Patients Resuscitated From Out-of-Hospital Cardiac Arrest

Background The kynurenine pathway (KP) is the major route of tryptophan (TRP) catabolism and is activated by inflammation and after cardiac arrest in animals. We hypothesized that the KP activation level correlates with severity of post–cardiac arrest shock, early death, and long‐term outcome. Methods and Results Plasma was obtained from 245 patients enrolled in a prospective multicenter observational study in 21 intensive care units in Finland. Time to return of spontaneous circulation, lowest systolic arterial pressure, and bicarbonate during the first 24 hours were collected. A cerebral performance category of 3 to 5 defined 12‐month poor outcome. Plasma TRP and KP metabolites, kynurenine (KYN), kynurenic acid, 3‐hydroxyanthranilic acid, and the ratio of KYN to TRP were measured by liquid chromatography and mass spectrometry. All KP metabolites at intensive care unit admission were significantly higher in cardiac arrest patients with a nonshockable rhythm compared to those with a shockable rhythm, and kynurenic acid and 3‐hydroxyanthranilic acid correlated with time to return of spontaneous circulation. Patients with higher levels of KYN, KYN to TRP, kynurenic acid, and 3‐hydroxyanthranilic acid had lower 24‐hour systolic arterial pressure and bicarbonate. All KP metabolites and the ratio of KYN to TRP, but not TRP, were significantly higher in patients who died in the intensive care unit in comparison to those who survived. Multivariable logistic regression showed that high kynurenic acid (odds ratio: 1.004; 95% confidence interval: 1.001 to 1.008; P=0.014), and 3‐hydroxyanthranilic acid (odds ratio: 1.011; 95% confidence interval: 1.001 to 1.022; P=0.03) were independently associated with 12‐month poor outcome and significantly improved risk reclassification. Conclusions KP is activated early after cardiac arrest and is associated with severity of post–cardiac arrest shock, early death, and poor long‐term outcome.

Prognostic value of high-sensitivity troponin T levels in patients with ventricular arrhythmias and out-of-hospital cardiac arrest: data from the prospective FINNRESUSCI study

IntroductionMyocardial dysfunction is common after out-of-hospital cardiac arrest (OHCA) and high-sensitivity troponin T (hs-TnT) levels may provide incremental prognostic information to established risk indices.MethodsA total of 155 patients with OHCA and a shockable rhythm (98% ventricular fibrillation; OHCA-VF/VT) had blood samples drawn within six hours of admission. Blood samples were also available after 24 hours, 48 hours, and 96 hours in subsets of patients. The endpoints of the study were hospital mortality and neurological status and mortality after one year.ResultsAdmission hs-TnT levels were higher than the 99-percentile of the general population (14 ng/L) in all patients (range 18 to 17837 ng/L). Admission hs-TnT levels were associated with acute coronary artery occlusion, time to return of spontaneous circulation, heart failure, and renal function. Admission hs-TnT levels were higher in one-year non-survivors compared to survivors (median 747 (quartile 1 to 3, 206 to 1061) ng/L versus 345 (184 to 740) ng/L, P =0.023) and in patients with a poor versus a favorable neurological outcome (739 (191 to 1061) ng/L versus 334 (195 to 716) ng/L, P =0.028). However, hs-TnT measurements did not add prognostic information to established risk variables in multivariate analyses. hs-TnT levels measured during the hospitalization for OHCA-VF/VT correlated closely with admission levels (r ≥0.63) and were inferior to Simplified Acute Physiology Score II (SAPS II) scores for the prediction of events during follow-up. hs-TnT dynamics did not discriminate between survivors and non-survivors or between a poor versus a favorable neurological outcome.Conclusionhs-TnT levels are elevated in critically ill patients with OHCA-VF/VT, but do not improve risk prediction.

Situational awareness and information flow in prehospital emergency medical care from the perspective of paramedic field supervisors: a scenario-based study

BackgroundIn prehospital emergency medical services, one of the key factors in the successful delivery of appropriate care is the efficient management and supervision of the area’s emergency medical services units. Paramedic field supervisors have an important role in this task. One of the key factors in the daily work of paramedic field supervisors is ensuring that they have enough of the right type of information when co-operating with other authorities and making decisions. However, a gap in information sharing still exists especially due to information overload. The aim of this study was to find out what type of critical information paramedic field supervisors need during multi-authority missions in order to manage their emergency medical services area successfully. The study also investigated both the flow of information, and interactions with the paramedic field supervisors and the differences that occur depending on the incident type.MethodsTen paramedic field supervisors from four Finnish rescue departments participated in the study in January–March 2012. The data were collected using semi-structured interviews based on three progressive real-life scenarios and a questionnaire. Data were analysed using deductive content analysis. Data management and analysis were performed using Atlas.ti 7 software.ResultsFive critical information categories were formulated: Incident data, Mission status, Area status, Safety at work, and Tactics. Each category’s importance varied depending on the incident and on whether it was about information needed or information delivered by the paramedic field supervisors. The main communication equipment used to receive information was the authority radio network (TETRA). However, when delivering information, mobile phones and TETRA were of equal importance. Paramedic field supervisors needed more information relating to area status.ConclusionsParamedic field supervisors communicate actively with EMS units and other authorities such as Emergency Medical Dispatch, police, and rescue services during the multi-authority incidents. This study provides knowledge about the critical information categories when receiving and sharing the information to obtain and maintain situational awareness. However, further research is needed to examine more the information flow in prehospital emergency care to enable a better understanding of required communication in situational awareness formation.