Tag Archives: ALS

Acute Med, All Updates, ICU, Kids, PHARM, Resus

Don't ignore the diastolic

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Most of us are pretty good at spotting hypotension and activating help or initiating therapy.
But ‘hypotension’ in many practitioners’ minds refers to a low systolic blood pressure. Who pays serious attention to the diastolic blood pressure? A low diastolic in a sick patient to me is a warning sign that their mean arterial pressure (MAP) is – or will be – low. After all, we spend about twice as long in diastole as in systole, so the diastolic pressure contributes more to the MAP than does the systolic.
A recent study showed that a low diastolic BP was one of several factors predictive of cardiac arrest on hospital wards: the most accurate predictors were maximum respiratory rate, heart rate, pulse pressure index, and minimum diastolic BP. These factors were more predictive than some of the variables included in the commonly used Early Warning Scores that trigger an emergency review.
The ‘pulse pressure index’ examined in the study is the pulse pressure divided by the systolic blood pressure (ie. [SBP-DBP]/SBP) which of course will be higher with lower diastolic blood pressures.
Importantly, the authors point out:


“In addition, our findings suggest that for many patients there is ample time prior to cardiac arrest to provide potentially life-saving interventions.”

…suggesting that there is still room for improvement in the identification and management of patients at risk for cardiac arrest, as the NCEPOD report ‘Cardiac Arrest Procedures: Time to Intervene?’ also showed.
They also recommend:


“…although systolic BP is commonly used in rapid response team activation criteria, incorporation of pulse pressure, pulse pressure index, or diastolic BP in place of systolic BP into the predictive model may be superior.”

Perhaps this may remind all of us to keep an eye on the diastolic as well as systolic BP when patients first present to us, and to include the importance of recognising diastolic hypotension in the teaching we provide our medical, paramedical and nursing students.

Predicting Cardiac Arrest on the Wards: A Nested Case-Control Study
Chest. 2012 May;141(5):1170-6 Free Full Text here
[EXPAND Click to read abstract]


Background: Current rapid response team activation criteria were not statistically derived using ward vital signs, and the best vital sign predictors of cardiac arrest (CA) have not been determined. In addition, it is unknown when vital signs begin to accurately detect this event prior to CA.

Methods: We conducted a nested case-control study of 88 patients experiencing CA on the wards of a university hospital between November 2008 and January 2011, matched 1:4 to 352 control subjects residing on the same ward at the same time as the case CA. Vital signs and Modified Early Warning Scores (MEWS) were compared on admission and during the 48 h preceding CA.

Results: Case patients were older (64 ± 16 years vs 58 ± 18 years; P = .002) and more likely to have had a prior ICU admission than control subjects (41% vs 24%; P = .001), but had similar admission MEWS (2.2 ± 1.3 vs 2.0 ± 1.3; P = .28). In the 48 h preceding CA, maximum MEWS was the best predictor (area under the receiver operating characteristic curve [AUC] 0.77; 95% CI, 0.71-0.82), followed by maximum respiratory rate (AUC 0.72; 95% CI, 0.65-0.78), maximum heart rate (AUC 0.68; 95% CI, 0.61-0.74), maximum pulse pressure index (AUC 0.61; 95% CI, 0.54-0.68), and minimum diastolic BP (AUC 0.60; 95% CI, 0.53-0.67). By 48 h prior to CA, the MEWS was higher in cases (P = .005), with increasing disparity leading up to the event.

Conclusions: The MEWS was significantly different between patients experiencing CA and control patients by 48 h prior to the event, but includes poor predictors of CA such as temperature and omits significant predictors such as diastolic BP and pulse pressure index.

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Acute Med, All Updates, ICU, Resus

Confidential stuff – in hospital cardiac arrests

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A new report describes room for improvement in the care of cardiac arrest patients in hospital1.
The National Confidential Enquiry into Patient Outcome and Death (NCEPOD) aimed to describe variability and identify remediable factors in the process of care of adult patients who receive resuscitation in hospital, including factors which may affect the decision to initiate the resuscitation attempt, the outcome and the quality of care following the resuscitation attempt, and antecedents in the preceding 48 hours that may have offered opportunities for intervention to prevent cardiac arrest.
Data were captured over a 14 day study period in late 2010 from UK hospitals, and were reviewed by an expert panel.
The summary is available here. I have picked out some findings of interest:

  • An adequate history was not recorded in 70/489 cases (14%) and clinical examination was incomplete at first contact in 117/479 cases (24%).

  • Appreciation of the severity of the situation was lacking in 74/416 (18%).

  • Timely escalation to more senior doctors was lacking in 61/347 (18%).

  • Decisions about CPR status were documented in the admission notes in 44/435 cases (10%). This is despite the high incidence of chronic disease and almost one in four cases being expected to be rapidly fatal on admission.

  • Where time to first consultant review could be identified it was more than 12 hours in 95/198 cases (48%).

  • Appreciation of urgency, supervision of junior doctors and the seeking of advice from senior doctors were rated ‘poor’ by Advisors.

  • Physiological instability was noted in 322/444 (73%) of patients who subsequently had a cardiac arrest.

  • Advisors considered that warning signs for cardiac arrest were present in 344/462 (75%) of cases. These warning signs were recognised poorly, acted on infrequently, and escalated to more senior doctors infrequently.

  • There was no evidence of escalation to more senior staff in patients who had multiple reviews.

  • Advisors considered that the cardiac arrest was predictable in 289/454 (64%) and potentially avoidable in 156/413 (38%) of cases.

  • The Advisors reported problems during the resuscitation attempt in 91/526 cases (17%). Of these, 36/91 were associated with airway management.

  • Survival to discharge after in-hospital cardiac arrest was 14.6% (85/581).

  • Only 9/165 (5.5%) patients who had an arrest in asystole survived to hospital discharge.

  • Survival to discharge after a cardiac arrest at night was much lower than after a cardiac arrest during the day time (13/176; 7.4% v 44/218; 20.1%).

 
In the opinion of the treating clinicians, earlier treatment of the problem and better monitoring may have improved outcome:

Compare these findings with a smaller scale confidential enquiry into the care of patients who ended up in intensive care units, published exactly 14 years ago by McQuillan et al2:
“The main causes of suboptimal care were failure of organisation, lack of knowledge, failure to appreciate clinical urgency, lack of supervision, and failure to seek advice.”
One of the co-authors of the McQuillan study, Professor Gary Smith , has spent years improving training in and awareness of the importance of recognition of critical illness, and pioneered the “ALERT” Course TM: Acute Life-threatening Emergencies, Recognition, and Treatment. Professor Smith provides commentary on the NCEPOD report and the slides are available here, including a reminder of the ‘Chain of Prevention’3.

It’s a shame these issues remain a problem but it is heartening to see NCEPOD tackle this important topic and provide recommendations that UK hospitals will have to act upon. It is further credit to the vision of Pete McQuillan, Gary Smith and their colleague Bruce Taylor (another co-author of the 1998 confidential inquiry). These guys opened my eyes to the world of critical care and trained me for 18 months on their ICU, which remains a beacon site for critical care expertise and training. Without their inspiration, I may not have ended up in emergency medicine-critical care and I doubt very much that Resus.ME would exist.

1. Cardiac Arrest Procedures: Time to Intervene? (2012)
National Confidential Enquiry into Patient Outcome and Death (NCEPOD)
2. Confidential inquiry into quality of care before admission to intensive care
BMJ 1998 Jun 20;316(7148):1853-8 Free Full Text
[EXPAND Click to read abstract]


OBJECTIVE: To examine the prevalence, nature, causes, and consequences of suboptimal care before admission to intensive care units, and to suggest possible solutions.

DESIGN: Prospective confidential inquiry on the basis of structured interviews and questionnaires.

SETTING: A large district general hospital and a teaching hospital.

SUBJECTS: A cohort of 100 consecutive adult emergency admissions, 50 in each centre.

MAIN OUTCOME MEASURES: Opinions of two external assessors on quality of care especially recognition, investigation, monitoring, and management of abnormalities of airway, breathing, and circulation, and oxygen therapy and monitoring.

RESULTS: Assessors agreed that 20 patients were well managed (group 1) and 54 patients received suboptimal care (group 2). Assessors disagreed on quality of management of 26 patients (group 3). The casemix and severity of illness, defined by the acute physiology and chronic health evaluation (APACHE II) score, were similar between centres and the three groups. In groups 1, 2, and 3 intensive care mortalities were 5 (25%), 26 (48%), and 6 (23%) respectively (P=0.04) (group 1 versus group 2, P=0.07). Hospital mortalities were 7 (35%), 30 (56%), and 8 (31%) (P=0.07) and standardised hospital mortality ratios (95% confidence intervals) were 1.23 (0.49 to 2.54), 1.4 (0.94 to 2.0), and 1.26 (0.54 to 2.48) respectively. Admission to intensive care was considered late in 37 (69%) patients in group 2. Overall, a minimum of 4.5% and a maximum of 41% of admissions were considered potentially avoidable. Suboptimal care contributed to morbidity or mortality in most instances. The main causes of suboptimal care were failure of organisation, lack of knowledge, failure to appreciate clinical urgency, lack of supervision, and failure to seek advice.

CONCLUSIONS: The management of airway, breathing, and circulation, and oxygen therapy and monitoring in severely ill patients before admissionto intensive care units may frequently be suboptimal. Major consequences may include increased morbidity and mortality and requirement forintensive care. Possible solutions include improved teaching, establishment of medical emergency teams, and widespread debate on the structure and process of acute care.

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3. In-hospital cardiac arrest: is it time for an in-hospital ‘chain of prevention’?
Resuscitation. 2010 Sep;81(9):1209-11
[EXPAND Click to read abstract]


The ‘chain of survival’ has been a useful tool for improving the understanding of, and the quality of the response to, cardiac arrest for many years. In the 2005 European Resuscitation Council Guidelines the importance of recognising critical illness and preventing cardiac arrest was highlighted by their inclusion as the first link in a new four-ring ‘chain of survival’. However, recognising critical illness and preventing cardiac arrest are complex tasks, each requiring the presence of several essential steps to ensure clinical success. This article proposes the adoption of an additional chain for in-hospital settings–a ‘chain of prevention’–to assist hospitals in structuring their care processes to prevent and detect patient deterioration and cardiac arrest. The five rings of the chain represent ‘staff education’, ‘monitoring’, ‘recognition’, the ‘call for help’ and the ‘response’. It is believed that a ‘chain of prevention’ has the potential to be understood well by hospital clinical staff of all grades, disciplines and specialties, patients, and their families and friends. The chain provides a structure for research to identify the importance of each of the various components of rapid response systems.

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Acute Med, All Updates, Guidelines, PHARM, Resus

Nonshockable arrest survival improves with uninterrupted compressions

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A study of nonshockable out of hospital cardiac arrest survival showed significant improvement in short- and long-term survival and neurological outcome after implementation of a protocol consistent with CPR guidelines that prioritised chest compressions. These improvements were especially evident among arrests attributable to a cardiac cause, although there was no evidence of harm among arrests attributable to a noncardiac cause.
This was not a randomised trial so unrecognised factors may have contributed to the improved outcome in addition to the change in CPR protocol. However, it is interesting as it provides up to date survival rates from a large population sample: Non shockable out of hospital cardiac arrests achieve return of spontaneous circulation in 34%, 6.8% are discharged from hospital (5.1% with a favourable neurological outcome), and 4.9% survived one year.
The breakdown between PEA and asystole is of course telling, and unsurprising, with 12.8% versus 1.1% being discharged with a favourable neurological outcome, respectively. I would imagine then that some of the PEA patients had beating hearts with hypotension extreme enough to cause pulselessness (pseudo-electromechanical dissociation) – clinically a ‘cardiac arrest’ but really nothing of the sort, and the reason we use cardiac ultrasound to prognosticate.


BACKGROUND: Out-of-hospital cardiac arrest (OHCA) claims millions of lives worldwide each year. OHCA survival from shockable arrhythmias (ventricular fibrillation/ tachycardia) improved in several communities after implementation of American Heart Association resuscitation guidelines that eliminated “stacked” shocks and emphasized chest compressions. “Nonshockable” rhythms are now the predominant presentation of OHCA; the benefit of such treatments on nonshockable rhythms is uncertain.

METHODS AND RESULTS: We studied 3960 patients with nontraumatic OHCA from nonshockable initial rhythms treated by prehospital providers in King County, Washington, over a 10-year period. Outcomes during a 5-year intervention period after adoption of new resuscitation guidelines were compared with the previous 5-year historical control period. The primary outcome was 1-year survival. Patient demographics and resuscitation characteristics were similar between the control (n=1774) and intervention (n=2186) groups, among whom 471 of 1774 patients (27%) versus 742 of 2186 patients (34%), respectively, achieved return of spontaneous circulation; 82 (4.6%) versus 149 (6.8%) were discharged from hospital, 60 (3.4%) versus 112 (5.1%) with favorable neurological outcome; 73 (4.1%) versus 135 (6.2%) survived 1 month; and 48 (2.7%) versus 106 patients (4.9%) survived 1 year (all P≤0.005). After adjustment for potential confounders, the intervention period was associated with an improved odds of 1.50 (95% confidence interval, 1.29-1.74) for return of spontaneous circulation, 1.53 (95% confidence interval, 1.14-2.05) for hospital survival, 1.56 (95% confidence interval, 1.11-2.18) for favorable neurological status, 1.54 (95% confidence interval, 1.14-2.10) for 1-month survival, and 1.85 (95% confidence interval, 1.29-2.66) for 1-year survival.

CONCLUSION: Outcomes from OHCA resulting from nonshockable rhythms, although poor by comparison with shockable rhythm presentations, improved significantly after implementation of resuscitation guideline changes, suggesting their potential to benefit all presentations of OHCA.

Impact of changes in resuscitation practice on survival and neurological outcome after out-of-hospital cardiac arrest resulting from nonshockable arrhythmia
Circulation. 2012 Apr 10;125(14):1787-94

Acute Med, All Updates, ICU, PHARM, Resus

End-Tidal CO2 as a Predictor of Cardiac Arrest Survival

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In one of largest studies to date of prehospital capnography in cardiac arrest, an initial EtCO2 >10 mmHg (1.3 kPa) was associated with an almost five-fold higher rate of return of spontaneous circulation (ROSC). In addition, a decrease in the EtCO2 during resuscitative events of >25% was associated with a significant increase in mortality, independent of other variables known to affect outcome.

The authors conclude: “EtCO2 values should be included as important variables in protocols to terminate or continue resuscitation in the prehospital setting“.


OBJECTIVE: The objective of this study was to evaluate initial end-tidal CO2 (EtCO2) as a predictor of survival in out-of-hospital cardiac arrest.

METHODS: This was a retrospective study of all adult, non-traumatic, out-of-hospital, cardiac arrests during 2006 and 2007 in Los Angeles, California. The primary outcome variable was attaining return of spontaneous circulation (ROSC) in the field. All demographic information was reviewed and logistic regression analysis was performed to determine which variables of the cardiac arrest were significantly associated with ROSC.

RESULTS: There were 3,121 cardiac arrests included in the study, of which 1,689 (54.4%) were witnessed, and 516 (16.9%) were primary ventricular fibrillation (VF). The mean initial EtCO2 was 18.7 (95%CI = 18.2-19.3) for all patients. Return of spontaneous circulation was achieved in 695 patients (22.4%) for which the mean initial EtCO2 was 27.6 (95%CI = 26.3-29.0). For patients who failed to achieve ROSC, the mean EtCO2 was 16.0 (95%CI = 15.5-16.5). The following variables were significantly associated with achieving ROSC: witnessed arrest (OR = 1.51; 95%CI = 1.07-2.12); initial EtCO2 >10 (OR = 4.79; 95%CI = 3.10-4.42); and EtCO2 dropping <25% during the resuscitation (OR = 2.82; 95%CI = 2.01-3.97).The combination of male gender, lack of bystander cardiopulmonary resuscitation, unwitnessed collapse, non-vfib arrest, initial EtCO2 ≤10 and EtCO2 falling > 25% was 97% predictive of failure to achieve ROSC.

CONCLUSIONS: An initial EtCO2 >10 and the absence of a falling EtCO2 >25% from baseline were significantly associated with achieving ROSC in out-of-hospital cardiac arrest. These additional variables should be incorporated in termination of resuscitation algorithms in the prehospital setting.

End-Tidal CO2 as a Predictor of Survival in Out-of-Hospital Cardiac Arres
Prehosp Disaster Med. 2011 Jun;26(3):148-50

All Updates, Kids, PHARM, Resus, Trauma

Out-of hospital traumatic paediatric cardiac arrest

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This small study on traumatic arrests in children1 refutes the “100% mortality from traumatic arrest” dogma that people still spout and gives information on the mechanisms associated with survival: drowning and strangulation were associated with greater rates of survival to hospital admission compared with blunt, penetrating, and other traumas. Overall, drowning had the greatest rate of survival to discharge (19.1%).
I would like to know the injuries sustained in non-survivors, to determine whether they were potentially treatable. Strikingly, in the list of prehospital procedures performed, there were NO attempts at pleural decompression, something that is standard in traumatic arrest protocols in prehospital services were I have worked.
It is interesting to compare these results with those of the London HEMS team2, who for traumatic paediatric arrest achieved 19/80 (23.8%) survival to discharged from the emergency department and 7/80 (8.75%) survival to hospital discharge. They also noted a large proportion of the survivors suffered hypoxic or asphyxial injuries, whereas those patients with hypovolaemic cardiac arrest did not survive.


OBJECTIVE:To determine the epidemiology and survival of pediatric out-of-hospital cardiac arrest (OHCA) secondary to trauma.

METHODS:The CanAm Pediatric Cardiac Arrest Study Group is a collaboration of researchers in the United States and Canada sharing a common goal to improve survival outcomes for pediatric cardiac arrest. This was a prospective, multicenter, observational study. Twelve months of consecutive data were collected from emergency medical services (EMS), fire, and inpatient records from 2000 to 2003 for all OHCAs secondary to trauma in patients aged ≤18 years in 36 urban and suburban communities supporting advanced life support (ALS) programs. Eligible patients were apneic and pulseless and received chest compressions in the field. The primary outcome was survival to discharge. Secondary measures included return of spontaneous circulation (ROSC), survival to hospital admission, and 24-hour survival.

RESULTS:The study included 123 patients. The median patient age was 7.3 years (interquartile range [IQR] 6.0-17.0). The patient population was 78.1% male and 59.0% African American, 20.5% Hispanic, and 15.7% white. Most cardiac arrests occurred in residential (47.1%) or street/highway (37.2%) locations. Initial recorded rhythms were asystole (59.3%), pulseless electrical activity (29.1%), and ventricular fibrillation/tachycardia (3.5%). The majority of cardiac arrests were unwitnessed (49.5%), and less than 20% of patients received chest compressions by bystanders. The median (IQR) call-to-arrival interval was 4.9 (3.1-6.5) minutes and the on-scene interval was 12.3 (8.4-18.3) minutes. Blunt and penetrating traumas were the most common mechanisms (34.2% and 25.2%, respectively) and were associated with poor survival to discharge (2.4% and 6.5%, respectively). For all OHCA patients, 19.5% experienced ROSC in the field, 9.8% survived the first 24 hours, and 5.7% survived to discharge. Survivors had triple the rate of bystander cardiopulmonary resuscitation (CPR) than nonsurvivors (42.9% vs. 15.2%). Unlike patients sustaining blunt trauma or strangulation/hanging, most post-cardiac arrest patients who survived the first 24 hours after penetrating trauma or drowning were discharged alive. Drowning (17.1% of cardiac arrests) had the highest survival-to-discharge rate (19.1%).

CONCLUSIONS:The overall survival rate for OHCA in children after trauma was low, but some trauma mechanisms are associated with better survival rates than others. Most OHCA in children is preventable, and education and prevention strategies should focus on those overrepresented populations and high-risk mechanisms to improve mortality.

1. Epidemiology of out-of hospital pediatric cardiac arrest due to trauma
Prehosp Emerg Care, 2012 vol. 16 (2) pp. 230-236
2. Outcome from paediatric cardiac arrest associated with trauma
Resuscitation. 2007 Oct;75(1):29-34

Acute Med, All Updates, Guidelines, PHARM, Resus

Epinephrine in cardiac arrest reanalysed

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A post hoc reanalysis was performed on a 2009 JAMA paper comparing patients randomised to receive or not receive prehospital drugs and iv access for cardiac arrest.
This was done to evaulate the effect of adrenaline/epinephrine. The reason for the reanalysis was that in the original intention-to-treat analysis, some of the following issues may have influenced the results:

  • Some patients randomised to adrenaline never received it as they had ROSC before the drug could be given, thus yielding a selection bias with the most easily resuscitated patients in the post hoc no-adrenaline group
  • At least 1 of 5 patients randomised to receive IV access and drugs did not receive adrenaline as it was regarded futile or it was impossible to gain intravenous access
  • 1 of 10 patients randomised to not receive drugs received adrenaline after they had regained spontaneous circulation for > 5 min.

The purpose of this post hoc analysis on the RCT data was to compare outcomes for patients actually receiving adrenaline to those not receiving adrenaline.
The actual use of adrenaline was associated with increased short-term survival, but with 48% less survival to hospital discharge. The improved survival to hospital admission is consistent with the results of a recent Australia study, and the negative association with longer term survival is similar to a multivariate analysis of observational Swedish registry data where patients receiving adrenaline were 57% less likely to be alive after one month.
Yet more evidence that we haven’t found any drugs proven to improve survival in cardiac arrest. At least not until the human studies on sodium nitroprusside come out?
I bet some of you are still going to be giving the epi exactly every four minutes though.
**Update: see Prehospital Epinephrine Use and Survival Among Patients With Out-of-Hospital Cardiac Arrest – more prospective data from Japan, this time showing epinephrine improves prehospital ROSC, but decreases chance of survival and good functional outcomes 1 month after the event.**


PURPOSE OF THE STUDY: IV line insertion and drugs did not affect long-term survival in an out-of-hospital cardiac arrest (OHCA) randomized clinical trial (RCT). In a previous large registry study adrenaline was negatively associated with survival from OHCA. The present post hoc analysis on the RCT data compares outcomes for patients actually receiving adrenaline to those not receiving adrenaline.

MATERIALS AND METHODS: : Patients from a RCT performed May 2003 to April 2008 were included. Three patients from the original intention-to-treat analysis were excluded due to insufficient documentation of adrenaline administration. Quality of cardiopulmonary resuscitation (CPR) and clinical outcomes were compared.

RESULTS: Clinical characteristics were similar and CPR quality comparable and within guideline recommendations for 367 patients receiving adrenaline and 481 patients not receiving adrenaline. Odds ratio (OR) for being admitted to hospital, being discharged from hospital and surviving with favourable neurological outcome for the adrenaline vs. no-adrenaline group was 2.5 (CI 1.9, 3.4), 0.5 (CI 0.3, 0.8) and 0.4 (CI 0.2, 0.7), respectively. Ventricular fibrillation, response interval, witnessed arrest, gender, age and endotracheal intubation were confounders in multivariate logistic regression analysis. OR for survival for adrenaline vs. no-adrenaline adjusted for confounders was 0.52 (95% CI: 0.29, 0.92).

CONCLUSION: Receiving adrenaline was associated with improved short-term survival, but decreased survival to hospital discharge and survival with favourable neurological outcome after OHCA. This post hoc survival analysis is in contrast to the previous intention-to-treat analysis of the same data, but agrees with previous non-randomized registry data. This shows limitations of non-randomized or non-intention-to-treat analyses.

Outcome when adrenaline (epinephrine) was actually given vs. not given – post hoc analysis of a randomized clinical trial
Resuscitation. 2012 Mar;83(3):327-32

Acute Med, All Updates, PHARM, Resus, Ultrasound

Prehospital echo predicts arrest outcome

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In hospital, the detection of cardiac standstill with ultrasound predicts a fatal outcome from cardiac arrest with a high degree of accuracy. A similar finding has been made in the prehospital setting. Interestingly, it was a better predictor than other commonly recognised factors associated with outcome: the presence of asystole, down time, bystander CPR, or end-tidal CO2 levels.


Introduction. The prognostic value of emergency echocardiography (EE) in the management of cardiac arrest patients has previously been studied in an in-hospital setting. These studies mainly included patients who underwent cardiopulmonary resuscitation (CPR) by emergency medicine technicians at the scene and who arrived at the emergency department (ED) still in a state of cardiac arrest. In most European countries, cardiac arrest patients are normally treated by physician-staffed emergency medical services (EMS) teams on scene. Transportation to the ED while undergoing CPR is uncommon. Objective. To evaluate the ability of EE to predict outcome in cardiac arrest patients when it is performed by ultrasound-inexperienced emergency physicians on scene.

Methods. We performed a prospective, observational study of nonconsecutive, nontrauma, adult cardiac arrest patients who were treated by physician-staffed urban EMS teams on scene. Participating emergency physicians (EPs) received a two-hour course in EE during CPR. After initial procedures were accomplished, EE was performed during a rhythm and pulse check. A single subxiphoid, four-chamber view was required for study enrollment. We defined sonographic evidence of cardiac kinetic activity as any detected motion of the myocardium, ranging from visible ventricular fibrillation to coordinated ventricular contractions. The CPR had to be continued for at least 15 minutes after the initial echocardiography. No clinical decisions were made based on the results of EE.

Results. Forty-two patients were enrolled in the study. The heart could be visualized successfully in all patients. Five (11.9%) patients survived to hospital admission. Of the 32 patients who had cardiac standstill on initial EE, only one (3.1%) survived to hospital admission, whereas four out of 10 (40%) patients with cardiac movement on initial EE survived to hospital admission (p = 0.008). Neither asystole on initial electrocardiogram nor peak capnography value, age, bystander CPR, or downtime was a significant predictor of survival. Only cardiac movement was associated with survival, and cardiac standstill at any time during CPR resulted in a positive predictive value of 97.1% for death at the scene.

Conclusion. Our results support the idea of focused echocardiography as an additional criterion in the evaluation of outcome in CPR patients and demonstrate its feasibility in the prehospital setting.

Cardiac Movement Identified on Prehospital Echocardiography Predicts Outcome
Prehosp Emerg Care. 2012 Jan 11. [Epub ahead of print]

Acute Med, All Updates, ICU, PHARM, Resus

Pre-hospital hypertonic saline during ACLS

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A newly published study examines pre-hospital hypertonic saline during CPR. A randomised trial compared 7.2% hypertonic saline / hydroxyethyl starch with hydroxyethyl starch alone in over 200 adult patients with non-traumatic out-of-hospital cardiac arrest. The volume infused was 2 ml /kg over 10 mins. All patients were resuscitated by the physicians of the Emergency Medical System (EMS) in Bonn, Germany.
There were no differences in survival to admission or discharge. There was a barely statistically significant increase in those survivors with higher cerebral performance categories (1 or 2) in the hypertonic saline group, inviting further study. The study was conducted from 2001 to 2004 (according to the 2000 CPR-Guidelines), so took an interestingly long time to see print.
Randomised study of hypertonic saline infusion during resuscitation from out-of-hospital cardiac arrest
Resuscitation. 2011 Sep 19. [Epub ahead of print]
[EXPAND Click to read abstract]


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.

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Acute Med, All Updates, ICU, Resus

Cardiac arrest caused by subarachnoid haemorrhage

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We know that subarachnoid haemorrhage (SAH) can cause cardiac arrest. Some questions we may have about this are:

Questions

  • What proportion of out-of-hospital cardiac arrests (OOHCA) who achieve return of spontaneous circulation (ROSC) are caused by SAH?
  • What is the usual presenting arrest rhythm – VT/VF or non-shockable rhythms?
  • What is the outcome of these patients – do any survive?
  • Do they have other characteristic cardiac features, such as ECG or echo abnormalities?
  • Should we do a head CT on all survivors of out-of-hospital cardiac arrest of uncertain aetiology?

A recent Japanese article in Resuscitation1 is the third from that country to be published on the topic in three years, the other two2,3 coming from different centres and all demonstrating some consistent answers, as do papers published in recent years from Europe4 and North America5:

Answers

  • Rates of SAH in OOHCA patients who achieve ROSC and make it to CT range from 4-16% (even higher if other sources of intracranial haemorrhage are included).
  • Studies consistently demonstrate VT/VF to be very rare – PEA and asystole are by far the commonest presenting arrest rhythms.
  • Almost no patients with this presentation due to SAH survive to hospital discharge.
  • In the most recent study, all patients who survived long enough to get a 12 lead showed ST-T abnormalities and/or QT prolongation, although echocardiograms were mostly normal.
  • Rates of SAH in OOHCA patients who achieve ROSC seem to be sufficiently high to seriously consider head CT in these patients if there is no obvious alternate explanation for the arrest.

1. Clinical and cardiac features of patients with subarachnoid haemorrhage presenting with out-of-hospital cardiac arrest
Resuscitation. 2011 Oct;82(10):1294-7
[EXPAND Abstract]


Background Subarachnoid haemorrhage (SAH) is known as one of the aetiologies of out-of-hospital cardiac arrest (OHCA). However, the mechanisms of circulatory collapse in these patients have remained unclear.

Methods and results We examined 244 consecutive OHCA patients transferred to our emergency department. Head computed tomography was performed on all patients and revealed the existence of SAH in 14 patients (5.9%, 10 females). Among these, sudden collapse was witnessed in 7 patients (50%). On their initial cardiac rhythm, all 14 patients showed asystole or pulseless electrical activity, but no ventricular fibrillation (VF). Return of spontaneous circulation (ROSC) was obtained in 10 of the 14 patients (14.9% of all ROSC patients) although all resuscitated patients died later. The ROSC rate in patients with SAH (71%) was significantly higher than that of patients with either other types of intracranial haemorrhage (25%, n = 2/8) or presumed cardiovascular aetiologies (22%, n = 23/101) (p < 0.01). On electrocardiograms, ST-T abnormalities and/or QT prolongation were found in all 10 resuscitated patients. Despite their electrocardiographic abnormalities, only 3 patients showed echocardiographic abnormalities.

Conclusions The frequency of SAH in patients with all causes of OHCA was about 6%, and in resuscitated patients was about 15%. The initial cardiac rhythm revealed no VF even though half had a witnessed arrest. A high ROSC rate was observed in patients with SAH, although none survived to hospital discharge.

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2. Assessing outcome of out-of-hospital cardiac arrest due to subarachnoid hemorrhage using brain CT during or immediately after resuscitation
Signa Vitae 2010; 5(2): 21 – 24 Full Text
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Objectives. The clinical course and outcome of out-of-hospital cardiopulmonary arrest (OHCPA) due to subarachnoid hemorrhage (SAH) is unclear. The objective of this study is to clarify them.

Study design. Single- center, observational study. Setting. We usually perform a brain computed tomography (CT) in OHCPA patients who present without a clear etiology (42% of all OHCPA), such as trauma, to determine the cause of OHCPA and to guide treatment.

Patients. The study included OHCPA patients without a clear etiology, who were transferred to our center and who underwent a brain CT during resuscitation.

Methods of measurement. Patients’ records were reviewed; initial cardiac rhythm, existence of a witness and bystander cardiopulmonary resuscitation efforts (CPR) were compared with patients’ outcomes.

Results. Sixty-six patients were enrolled. 72.7% achieved return of spontaneous circulation (ROSC), 71.2% were admitted, 30.3% survived more than 7 days, and 9.1. survived-to-discharge. In 41 witnessed OHCPA, 87.8% obtained ROSC, 85.4% were admitted, and 14.6% survived-to-discharge. All survivors were witnessed. In 25 non-witnessed OHCPA, 48% obtained ROSC and were admitted, and no patients were discharged. Initial cardiac rhythm was ventricular fibrillation (VF), pulseless electrical activity (PEA) and asystole in 3.0%, 39.4%, and 47.0%. In 2 VF patients 50.0% survived-to- discharge, and there was no survivor with PEA or asystole.

Conclusion. This study shows a high rate of ROSC and admission in OHCPA patients with a SAH, and also reveals their very poor neurological outcome. We conclude that the detection of a SAH in OHCPA patients is important to determine the accurate frequency of SAH in this patient group and to guide appropriate treatment of all OHCPA patients.

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3. Subarachnoid haemorrhage as a cause of out-of-hospital cardiac arrest: A prospective computed tomography study
Resuscitation. 2009 Sep;80(9):977-80
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Aim Aneurysmal subarachnoid haemorrhage (SAH) is a relatively common cause of out-of-hospital cardiac arrest (OHCA). Early identification of SAH-induced OHCA with the use of brain computed tomography (CT) scan obtained immediately after resuscitation may help emergency physicians make therapeutic decision as quickly as they can.

Methods During the 4-year observation period, brain CT scan was obtained prospectively in 142 witnessed non-traumatic OHCA survivors who remained haemodynamically stable after resuscitation. Demographics and clinical characteristics of SAH-induced OHCA survivors were compared with those with “negative” CT finding.

Results Brain CT scan was feasible with an average door-to-CT time of 40.0min. SAH was found in 16.2% of the 142 OHCA survivors. Compared with 116 survivors who were negative for SAH, SAH-induced OHCA survivors were significantly more likely to be female, to have experienced a sudden headache, and trended to have achieved return of spontaneous circulation (ROSC) prior to arrival in the emergency department less frequently. Ventricular fibrillation (VF) was significantly less likely to be seen in SAH-induced than SAH-negative OHCA (OR, 0.06; 95% CI, 0.01–0.46). Similarly, Cardiac Trop-T assay was significantly less likely to be positive in SAH-induced OHCA (OR, 0.08; 95% CI, 0.01–0.61).

Conclusion Aneurysmal SAH causes OHCA more frequently than had been believed. Immediate brain CT scan may particularly be useful in excluding SAH-induced OHCA from thrombolytic trial enrollment, for whom the use of thrombolytics is contraindicated. The low VF incidence suggests that VF by itself may not be a common cause of SAH-induced OHCA.

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4. Spontaneous subarachnoid haemorrhage as a cause of out-of-hospital cardiac arrest
Resuscitation. 2001 Oct;51(1):27-32
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Objective: Spontaneous subarachnoid haemorrhage as a cause of out-of-hospital cardiac arrest is poorly evaluated. We analyse disease-specific and emergency care data in order to improve the recognition of subarachnoid haemorrhage as a cause of cardiac arrest.

Design: We searched a registry of cardiac arrest patients admitted after primarily successful resuscitation to an emergency department retrospectively and analysed the records of subarachnoid haemorrhage patients for predictive features.

Results: Over 8.5 years, spontaneous subarachnoidal haemorrhage was identified as the immediate cause in 27 (4%) of 765 out-of-hospital cardiac arrests. Of these 27 patients, 24 (89%) presented with at least three or more of the following common features: female gender (63%), age under 40 years (44%), lack of co-morbidity (70%), headache prior to cardiac arrest (39%), asystole or pulseless electric activity as the initial cardiac rhythm (93%), and no recovery of brain stem reflexes (89%). In six patients (22%), an intraventricular drain was placed, one of them (4%) survived to hospital discharge with a favourable outcome.

Conclusions: Subarachnoid haemorrhage complicated by cardiac arrest is almost always fatal even when a spontaneous circulation can be restored initially. This is due to the severity of brain damage. Subarachnoid haemorrhage may present in young patients without any previous medical history with cardiac arrest masking the diagnosis initially.

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5. Cranial computed tomography in the resuscitated patient with cardiac arrest
Am J Emerg Med. 2009 Jan;27(1):63-7
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Introduction The incidence of out-of-hospital and in-hospital cardiorespiratory arrest from all causes in the United States occurs not infrequently. Postresuscitation care should include the identification of the inciting arrest event as well as therapy tailored to support the patient and treat the primary cause of the decompensation. The application of one particular testing modality, cranial computed tomography (CT) of the head, has not yet been determined. We undertook an evaluation of the use of head CT in patients who were resuscitated from cardiac arrest.

Methods Prehospital (emergency medical services), ED, and hospital records were reviewed for patients of all ages with cardiorespiratory arrest over a 4-year period (July 1996-June 2000). Information regarding diagnosis, management, and outcome was recorded. The results of cranial CT, if performed, and any apparent resulting therapeutic changes were recorded. Patients with a known traumatic mechanism for the cardiorespiratory arrest were excluded.

Results A total of 454 patients (mean age 58.3 years with 60% male) with cardiorespiratory arrest were entered in the study with 98 (22%) individuals (mean age 58.5 years with 53% male) undergoing cranial CT. Arrest location was as follows: emergency medical services, 41 (42%); ED, 11 (11%); and hospital, 46 (47%). Seventy-eight (79%) patients demonstrated 111 CT abnormalities: edema, 35 (32%); atrophy, 24 (22%); extra-axial hemorrhage, 14 (13%); old infarct, 12 (11%); new infarct, 11 (10%); intraparenchymal hemorrhage, 6 (5%); skull fracture, 5 (4%); mass, 3 (2%); and foreign body, 1 (1%). Therapeutic and diagnostic alterations in care were made in 38 (39%) patients—35 abnormal and 3 normal CTs. The following alterations occurred: medication administration, 26; withdrawal of life support, 7; additional diagnostic study, 6; neurologic consultation, 6; and intracranial pressure monitoring. 4. No patient survived to discharge.

Conclusion In this subset of resuscitated patients with cardiac arrest, abnormalities on the head CT were not uncommon. Alterations in management did occur in those patients with abnormalities. The indications and impact of head CT in the population of resuscitated patients with cardiac arrest remain unknown, warranting further investigation.

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Acute Med, All Updates, Guidelines, ICU, Resus

Myoclonus no longer a show-stopper

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In comatose survivors of cardiac arrest, myoclonus is considered a grave prognostic sign. The American Academy of Neurology stated in 20061 that:
After cardiac arrest, the following clinical findings accurately predict poor outcome;

  • myoclonus status epilepticus within the first 24 hours in patients with primary circulatory arrest
  • absence of pupillary responses within days 1 to 3 after CPR
  • absent corneal reflexes within days 1 to 3 after CPR
  • and absent or extensor motor responses after 3 days.

However in the age of targeted temperature management the presence and/or timing of these signs needs to be re-evaluated. It has been suggested that therapeutic hypothermia and sedation required for induced cooling might delay recovery of motor reactions up to 5–6 days after cardiac arrest. Now a series of three survivors of cardiac arrest who had massive myoclonus in the first four hours after return of spontaneous circulation (ROSC) is reported2, all of whom were treated with TTM and experienced good neurologic outcomes.


Early myoclonus in comatose survivors of cardiac arrest, even when it is not myoclonic status epilepticus (MSE), is considered a sign of severe global brain ischemia and has been associated with high rates of mortality and poor neurologic outcomes. We report on three survivors of primary circulatory cardiac arrests who had good neurologic outcomes (two patients with a CPC score=1 and one patient with a CPC score=2) after mild therapeutic hypothermia, despite exhibiting massive myoclonus within the first four hours after return of spontaneous circulation. The concept that early myoclonus heralds a uniformly poor prognosis may need to be reconsidered in the era of post-cardiac arrest mild therapeutic hypothermia.

1. Practice Parameter: Prediction of outcome in comatose survivors after cardiopulmonary resuscitation (an evidence-based review): Report of the Quality Standards Subcommittee of the American Academy of Neurology
Neurology. 2006 Jul 25;67(2):203-10 Full Text
2. Neurologic Recovery After Therapeutic Hypothermia in Patients with Post-Cardiac Arrest Myoclonus
Resuscitation published on line 03 October 2011