An observational study of bispectral index monitoring for out of hospital cardiac arrest

Cerebral resuscitation is the most important goal of advanced life support. Currently, there are no objective monitoring methods available to gauge the effectiveness of advanced life support on cerebral resuscitation. We assessed the utility of bispectral index (BIS) monitoring during cardiopulmonary resuscitation as a marker of cerebral resuscitation. Twenty one patients with out of hospital cardiac arrest had a BIS monitor applied during the resuscitation, in addition to standard advanced life support. The BIS monitor was also applied to a cadaver to assess the role of artefact. Illustrative data are presented, outlining the process of evaluation undertaken. A major component of the BIS tracing during external chest compressions appears to be due to movement artefact. Our pilot data indicate that with current technology, BIS monitoring is not a clinically reliable marker of the efficacy of external chest compressions.     

Treatment and outcome of out-of-hospital cardiac arrest in outpatient health care facilities

AimWe evaluated the frequency and effectiveness of basic and advanced life support (ALS) interventions by medical professionals when out-of-hospital cardiac arrest (OHCA) occurred in ambulatory healthcare clinics before emergency medical services (EMS) arrival.MethodsNon-traumatic OHCAs in adults were systematically characterized over a 15 year period by their occurrence in clinics, at home, or in non-medical public locations, and outcomes compared between matched cohorts from each group.ResultsAmong 7784 patients, 6098 OHCA occurred at home, 1612 in non-medical public locations and 74 in clinics. Compared to non-medical public locations, clinic patients with OHCA were older, more often women and more frequently shocked; clinic arrests were more often witnessed, less likely to be of cardiac cause and to occur before EMS arrival. Compared to home, more clinic arrests were witnessed, occurred after EMS arrival, had bystander CPR, shockable rhythms and were defibrillated. When OHCA occurred before EMS arrival, 51 of 56 clinic patients (91%) received CPR, a defibrillator applied to 23 (41%), 17 (30%) were shocked, 4 (7%) intubated, and 7 (13%) received intravenous medications from facility personnel. Of these, only pre-EMS defibrillator use was associated with improved outcome. Among matched patients, OHCA survival was higher in clinics than at home (42% vs 26%, p = 0.029), but comparable to other public locations.ConclusionsSurvival from OHCA in clinics was comparable to non-medical public locations, and higher than at home. Alongside CPR, use of defibrillators was associated with improved survival and worth prioritizing over other interventions before EMS arrival regardless of OHCA location.     

A 5-year experience with cardiopulmonary resuscitation using extracorporeal life support in non-postcardiotomy patients with cardiac arrest

Background

Cardiopulmonary resuscitation (CPR) using extracorporeal life support (ECLS) system has been successfully used to support patients with in- and out-of-hospital cardiac arrest (IHCA, OHCA) when conventional measures have failed. The purpose of the current study is to report on our experience with extracorporeal CPR in non-postcardiotomy patients.

Methods

We retrospectively analysed a total of 85 consecutive adult patients, who have been treated with ECLS between January 2007 and January 2012.

Results

The mean CPR duration was 40 min (20–70 min). The mean ECLS support duration was 49 h (12–92 h). Twenty-eight patients (33%) had ECLS related complications. Forty patients (47%) were successfully weaned and 29 patients (34%) survived to hospital discharge. Among survivors, 93% were without severe neurologic deficit. Duration of CPR was shorter for survivors than for non-survivors [(25: 20–50 min) vs. (50: 25–86 min); p = 0.003]. Immediately after ECLS start, the mean blood lactate level was lower (p = 0.003), and the mean pH value was higher in the survivors’ group (p < 0.0001) compared to the non-survivors’ group. The CPR duration for the IHCA group (25: 20–50 min) was shorter compared to the OHCA group (70: 55–110 min; p < 0.0001). The survival rate in this group was higher compared to the OHCA group (42% vs. 15%; p < 0.02).

Conclusions

CPR using modern miniaturized ECLS systems should be established in the treatment of prolonged cardiac arrest and unsuccessful conventional CPR in selected patients. CPR with ECLS for OHCA has worse outcomes compared to IHCA. Duration of CPR was independent risk factor for mortality after extracorporeal CPR.     

The clinical significance of a failed initial intubation attempt during emergency department resuscitation of out-of-hospital cardiac arrest patients

Objective

Advanced airway management is one of the fundamental skills of advanced cardiac life support (ACLS). A failed initial intubation attempt (FIIA) is common and has shown to be associated with adverse events. We analysed the association between FIIA and the overall effectiveness of ACLS.

Methods

Using emergency department (ED) out-of-hospital cardiac arrest (OHCA) registry data from 2008 to 2012, non-traumatic ED-resuscitated adult OHCA patients on whom endotracheal intubation was initially tried were identified. Prehospital and demographic factors and patient outcomes were retrieved from the registry. The presence of a FIIA was determined by reviewing nurse-documented CPR records. The primary outcome was achieving a return of spontaneous circulation (ROSC). The secondary outcomes were time to ROSC and the ROSC rate during the first 30 min of ED resuscitation.

Results

The study population (n = 512) was divided into two groups based on the presence of a FIIA (N = 77). Both groups were comparable without significant differences in demographic or prehospital factors. In the FIIA group, the unadjusted and adjusted odds ratios (ORs) for achieving a ROSC were 0.50 (95% confidence interval [CI], 0.31–0.81) and 0.40 (95% CI, 0.23–0.71), respectively. Multivariable median regression analysis revealed that FIIA was associated with an average delay of 3 min in the time to ROSC (3.08; 95% CI, 0.08–5.80). Competing risk regression analysis revealed a significantly slower ROSC rate during the first 15 min (adjusted subhazard ratio, 0.52; 95% CI, 0.35–0.79) in the FIIA group.

Conclusion

FIIA is an independent risk factor for the decreased effectiveness of ACLS.     

Randomised study of hypertonic saline infusion during resuscitation from out-of-hospital cardiac arrest

Aim of the study

Animal models of hypertonic saline infusion during cardiopulmonary resuscitation (CPR) improve survival, as well as myocardial and cerebral perfusion during CPR. We studied the effect of hypertonic saline infusion during CPR (Guidelines 2000) on survival to hospital admission and hospital discharge, and neurological outcome on hospital discharge.

Methods

The study was performed by the EMS of Bonn, Germany, with ethical committee approval. Study inclusion criteria were non-traumatic out-of-hospital cardiac arrest, aged 18–80 years, and given of adrenaline (epinephrine) during CPR. Patients were randomly infused 2 ml kg⁻¹ HHS (7.2% NaCl with 6% hydroxyethyl starch 200,000/0.5 [HES]) or HES over 10 min.

Results

203 patients were randomised between May 2001 and June 2004. After HHS infusion, plasma sodium concentration increased significantly to 162 ± 36 mmol l⁻¹ at 10 min after infusion and decreased to near normal (144 ± 6 mmol l⁻¹) at hospital admission. Survival to hospital admission and hospital discharge was similar in both groups (50/100 HHS vs. 49/103 HES for hospital admission, 23/100 HHS vs. 22/103 HES for hospital discharge). There was a small improvement in neurological outcome in survivors on discharge (cerebral performance category 1 or 2) in the HHS group compared to the HES group (13/100 HHS vs. 5/100 HES, p < 0.05, odds-ratio 2.9, 95% confidence interval 1.004–8.5).

Conclusion

Hypertonic saline infusion during CPR using Guidelines 2000 did not improve survival to hospital admission or hospital discharge. There was a small improvement with hypertonic saline in the secondary endpoint of neurological outcome on discharge in survivors. Further adequately powered studies using current guidelines are needed.     

Education for cardiac arrest – Treatment or prevention?

In-hospital cardiac arrests (IHCA) occur infrequently and individual staff members working on general wards may only rarely encounter one. Mortality following IHCA is high and the evidence for the benefits of many advanced life support (ALS) interventions is scarce. Nevertheless, regular, often frequent, ALS training is mandatory for many hospital medical staff and nurses. The incidence of pre-cardiac arrest deterioration is much higher than that of cardiac arrests, and there is evidence that intervention prior to cardiac arrest can reduce the incidence of IHCA. This article discusses a proposal to reduce the emphasis on widespread ALS training and to increase education in the recognition and response to pre-arrest clinical deterioration.     

Inconsistencies in cardiac arrest reporting

Data relating to survival from in-hospital cardiac arrest are used to audit staff performance and to help to determine whether new resuscitation techniques are effective. Individual studies into outcome from cardiac arrest have defined inclusion and exclusion criteria, but no such national criteria have been published to enable constant auditing of cardiac arrests. The aim of this survey was to investigate the consistency with which in-hospital cardiac arrests are recorded throughout the United Kingdom. Such data are, almost universally, collected by Resuscitation Officers (RO). A questionnaire was sent to ROs across the UK asking them to state how they would interpret and categorise hypothetical, but nonetheless typical, clinical situations involving a cardiac arrest team being called. These included an event where the patient had regained consciousness prior to the arrival of the cardiac team and also an event where rigor mortis was already present and the resuscitation promptly abandoned upon the arrival of the cardiac arrest team. The percentage survival to discharge of adult cardiac arrests for each hospital was also requested. This identified whether inclusion or exclusion of certain clinical events may have influenced cardiac arrest survival figures for that hospital. It is clear from this study that in-hospital clinical events when a cardiac arrest team is called are audited with a great deal of inconsistency. Some events, such as a patient who has rigor mortis, are excluded as a false or inappropriate call in some hospitals and included as an unsuccessful resuscitation in others. There is a need for guidance on the inclusion and exclusion criteria for auditing of cardiac arrests so that meaningful data can be obtained from across the UK and useful conclusions drawn. The situation at present will result in data being audited that are of limited use. In the era of evidence-based medicine, it seems vital to obtain accurate cardiac arrest survival figures in order to have any hope of improving them.     

Out-of-hospital cardiac arrest

Myocardial disease and death from cardiac arrest remain significant public health problems. Sudden death events and out-of-hospital cardiac arrests (OHCA) are encountered frequently by emergency medical services. Despite more than 30 years of research, survival rates remain extremely low. This article reviews access and presentations, demographics, OHCA outcomes, and response systems and processes in treatment of patients with arrest in this setting.     

Effects of repeated epinephrine administration and administer timing on witnessed out-of-hospital cardiac arrest patients

Background

Repeated administration of epinephrine is associated with unfavorable cerebral outcome after out-of-hospital cardiac arrests (OHCA), but the timing of epinephrine administration has not been considered.

A national resuscitation registry of out-of-hospital cardiac arrest in Germany—A pilot study

Background

Survival rate after out-of-hospital cardiac arrest (OHCA) has not significantly increased over the last decade. However, survival rate has been used as a quality benchmark for many emergency medical services. A uniform resuscitation registry may be advantageous for quality management of cardiopulmonary resuscitation (CPR). This study was conducted to evaluate the establishment of a national CPR registry in Germany.

Materials and methods

A prospective cohort study was performed that included 469 patients who experienced OHCA requiring CPR in the metropolitan area of Dortmund, Germany. Cardiac arrest was defined as concomitant appearance of unconsciousness, apnoea or gasping and pulselessness. All data were collected via a secure and confidential paper-based method as the data set ‘Preclinical care’.

Results

Quality of data was classified as ‘good’ in 33.4%, ‘moderate’ in 48.4%, and ‘bad’ in 18.2% of the patients, respectively. Sixty-two percent had OHCA in private residences, 24% of the patients had a first monitored rhythm of ventricular fibrillation (VF) or ventricular tachycardia (VT), 35.2% had return of spontaneous circulation (ROSC) on scene, and patients presenting VF/VT as the first monitored rhythm had higher ROSC rates (51.3%) compared to patients with asystole (22.6%).

Conclusion

The data set ‘Preclinical care’ proved to be congruent with the Utstein style, provided further information for national and international comparisons, and enabled a detailed analysis. Optimisation of data collection and introduction of strict control mechanisms may further improve data quality.     

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 48 h 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 PaCO₂ 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.     

A phased approach to cardiac arrest resuscitation involving ventricular fibrillation and pulseless ventricular tachycardia

With the release of the 2010 American Heart Association (AHA) Guidelines for cardiopulmonary resuscitation and emergency cardiac care, evidence regarding management of out-of-hospital cardiac arrest suggests a more fundamental approach. To aid in understanding and learning, this article proposes a method that optimizes the timing and delivery of evidence-proven therapies with a 3-phase approach for out-of-hospital resuscitation from ventricular fibrillation and pulseless ventricular tachycardia. Although this model is not a new concept, it is largely based on the 2010 AHA Guidelines, enhancing the philosophy of the "CAB" concept (Chest compressions/Airway management/Breathing rescue).     

Prevalence and effect of fever on outcome following resuscitation from cardiac arrest

Objective

Evaluate the prevalence of fever in the first 48 h after cardiac arrest and its effect on outcomes.

Methods

Review of patients treated between 1/1/2005 and 6/30/2010. Fever was defined as T ≥ 38.0 °C. We classified categories of post-cardiac arrest illness severity as (I) awake, (II) coma + mild cardiopulmonary dysfunction (SOFA cardiac + respiratory score <4), (III) coma + moderate-severe cardiopulmonary dysfunction, and (IV) deep coma. Associations between fever and survival or good neurologic outcome were examined between hypothermia (TH) and non-TH groups.

Results

In 336 patients, mean age was 60 years (SD 16), 63% experienced out-of-hospital cardiac arrest and 65% received TH. A shockable rhythm was present in 40%. Post arrest illness severity was category II in 38%, category III in 20%, and category IV in 42%. Fever was present in 42% of subjects, with a post-arrest median onset of 15 h in the non-TH cohort and 36 h in TH cohort. Fever was not associated with survival within the whole cohort (OR 0.32, CI 0.15, 0.68) or TH cohort (OR 1.21, CI 0.69, 2.14), but was associated with survival in non-TH cohort (OR 0.47, CI 0.20, 1.10). Fever was not associated with good outcomes in the whole cohort (OR 0.83, CI 0.49, 1.40), TH cohort (OR 1.09, CI 0.56, 2.12) or non-TH cohort (OR 0.34, CI 0.11, 1.06).

Conclusions

The development of fever within the first 48 h after ROSC is common. Fever is associated with death in non-TH patients. TH treatment appears to mitigate this effect, perhaps by delaying fever onset.     

Hypothermia and neuroprotection by sulfide after cardiac arrest and cardiopulmonary resuscitation

Background

Poor neurological outcome remains a major problem in patients suffering cardiac arrest. Recent data have demonstrated potent neuroprotective effects of the administration of sulfide donor compounds after ischaemia/reperfusion injury following cardiac arrest and resuscitation. Therefore, we sought to evaluate the impact of sodium sulfide (Na₂S), a liquid hydrogen sulfide donor on core body temperature and neurological outcome after cardiac arrest in rats.

Methods

Fifty male Wistar rats were randomized into two groups (sulfide vs. placebo, n = 25 per group). Cardiac arrest was induced by transoesophageal ventricular fibrillation during general anaesthesia. After 6 min of global cerebral ischaemia, animals were resuscitated by external chest compressions combined with defibrillation. An investigator blinded bolus of either Na₂S (0.5 mg/kg body weight) or placebo 1 min before the beginning of CPR, followed by a continuous infusion of Na₂S (1 mg/kg body weight/h) or placebo for 6 h, was administered intravenously. 1 day, 3 days, and 7 days after restoration of spontaneous circulation, neurological outcome was evaluated by a tape removal test. After 7 days of reperfusion, coronal brain sections were analyzed by TUNEL- and Nissl-staining. A caspase activity assay was used to determine antiapoptotic properties of Na₂S.

Results

Temperature course was similar in both groups (mean minimal temperature in the sulfide group 31.3 ± 1.2 °C vs. 30.8 ± 1.9 °C in the placebo group; p = 0.29). Despite significant neuroprotection demonstrated by the tape removal test after 3 days of reperfusion in the sulfide treated group, there was no significant difference in neuronal survival at day 7. Likewise results from TUNEL-staining revealed no differences in the amount of apoptotic cell death between the groups after 7 days of reperfusion.

Conclusion

In our rat model of cardiac arrest, sulfide therapy was associated with only a short term beneficial effect on neurological outcome.     

Hypocalcemia following resuscitation from cardiac arrest revisited

Objective

Hypocalcemia associated with cardiac arrest has been reported. However, mechanistic hypotheses for the decrease in ionized calcium (iCa) vary and its importance unknown. The objective of this study was to assess the relationships of iCa, pH, base excess (BE), and lactate in two porcine cardiac arrest models, and to determine the effect of exogenous calcium administration on post-resuscitation hemodynamics.

Methods

Swine were instrumented and VF was induced either electrically (EVF, n = 65) or spontaneously, ischemically induced (IVF) with balloon occlusion of the LAD (n = 37). Animals were resuscitated after 7 min of VF. BE, iCa, and pH, were determined prearrest and at 15, 30, 60, 90, 120 min after ROSC. Lactate was also measured in 26 animals in the EVF group. Twelve EVF animals were randomized to receive 1 g of CaCl₂ infused over 20 min after ROSC or normal saline.

Results

iCa, BE, and pH declined significantly over the 60 min following ROSC, regardless of VF type, with the lowest levels observed at the nadir of left ventricular stroke work post-resuscitation. Lactate was strongly correlated with BE (r = −0.89, p < 0.0001) and iCa (r = −0.40, p < 0.0001). In a multivariate generalized linear mixed model, iCa was 0.005 mg/dL higher for every one unit increase in BE (95% CI 0.003-0.007, p < 0.0001), while controlling for type of induced VF. While there was a univariate correlation between iCa and BE, when BE was included in the regression analysis with lactate, only lactate showed a statistically significant relationship with iCa (p = 0.02). Post-resuscitation CaCl₂ infusion improved post-ROSC hemodynamics when compared to saline infusion (LV stroke work control 8 ± 5 g m vs 23 ± 4, p = 0.014, at 30 min) with no significant difference in tau between groups.

Conclusions

Ionized hypocalcemia occurs following ROSC. CaCl₂ improves post-ROSC hemodynamics suggesting that hypocalcemia may play a role in early post-resuscitation myocardial dysfunction.     

1例心搏骤停复苏后患者的人工亚低温循证治疗

目的为1例心搏骤停复苏后昏迷患者制定人工亚低温循证治疗方案。方法针对提出的临床问题，检索Medline（1981—2006年）和Cochrane图书馆（2006年第2期）。结果检索发现，关于心搏骤停复苏后人工亚低温治疗RCT3篇和SR1篇，通过分析检索结果、结合临床医生经验及患者实际情况，为患者制定了循证治疗方案，通过6个月随访发现证实，该方案适合患者。结论对心搏骤停复苏后昏迷者，采用人工亚低温治疗可改善患者的预后。     

In-hospital cardiac arrest: incidence,prognosis and possible measures to improve survival

Design Review. Objective Medical literature on in-hospital cardiac arrest (IHCA) was reviewed to summarise: (a) the incidence of and survival after IHCA, (b) major prognostic factors, (c) possible interventions to improve survival. Results and conclusions The incidence of IHCA is rarely reported in the literature. Values range between 1 and 5 events per 1,000 hospital admissions, or 0.175 events/bed annually. Reported survival to hospital discharge varies from 0% to 42%, the most common range being between 15% and 20%. Pre-arrest prognostic factors: the prognostic value of age is controversial. Among comorbidities, sepsis, cancer, renal failure and homebound lifestyle are significantly associated with poor survival. However, pre-arrest morbidity scores have not yet been prospectively validated as instruments to predict failure to survive after IHCA. Intra-arrest factors: ventricular fibrillation/ventricular tachycardia (VF/VT) as the first recorded rhythm and a shorter interval between IHCA and cardiopulmonary resuscitation or defibrillation are associated with higher survival. However, VF/VT is present in only 25–35% of IHCAs. Short-term survival is also higher in patients resuscitated with chest compression rates above 80/min. Interventions likely to improve survival include: early recognition and stabilisation of patients at risk of IHCA to enable prevention, faster and better in-hospital resuscitation and early defibrillation. Mild therapeutic hypothermia is effective as post-arrest treatment of out-of-hospital cardiac arrest due to VF/VT, but its benefit after IHCA and after cardiac arrest with non-VF/VT rhythms has not been clearly demonstrated.     

Systematic review of quality of life and other patient-centred outcomes after cardiac arrest survival

Objectives

In cardiac arrest patients (in hospital and pre hospital) does resuscitation produce a good Quality of Life (QoL) for survivors after discharge from the hospital?

Methods

Embase, Medline, The Cochrane Database of Systematic Reviews, Academic Search Premier, the Central Database of Controlled Trials and the American Heart Association (AHA) Resuscitation Endnote Library were searched using the terms (‘Cardiac Arrest’ (Mesh) OR ‘Cardiopulmonary Resuscitation’ (Mesh) OR ‘Heart Arrest’ (Mesh)) AND (‘Outcomes’ OR ‘Quality of Life’ OR ‘Depression’ OR ‘Post-traumatic Stress Disorder’ OR ‘Anxiety OR ‘Cognitive Function’ OR ‘Participation’ OR ‘Social Function’ OR ‘Health Utilities Index’ OR ‘SF-36’ OR ‘EQ-5D’ as text term.

Results

There were 9 inception (prospective) cohort studies (LOE P1), 3 follow up of untreated control groups in randomised control trials (LOE P2), 11 retrospective cohort studies (LOE P3) and 47 case series (LOE P4). 46 of the studies were supportive with respect to the search question, 17 neutral and 7 negative.

Discussion

The majority of studies concluded that QoL after cardiac arrest is good. This review demonstrated a remarkable heterogeneity of methodology amongst studies assessing QoL in cardiac arrest survivors. There is a requirement for consensus development with regard to quality of life and patient centred outcome assessment in this population.