Tag Archives: arrest

Advanced airways and worse outcomes in cardiac arrest

A new study demonstrates an association between advanced prehospital airway management and worse clinical outcomes in patients with cardiac arrest. Done in Japan, the numbers of patients included are staggering: this nationwide population-based cohort study included 658 829 adult patients. They found that CPR with advanced airway management (use of tracheal tubes and even supraglottic airways) was a significant predictor of poor neurological outcome compared with conventional bag-valve-mask ventilation.
Association of Prehospital Advanced Airway Management With Neurologic Outcome and Survival in Patients With Out-of-Hospital Cardiac Arrest
JAMA 2013;309(3):257-66
[EXPAND Click to read abstract]


Importance It is unclear whether advanced airway management such as endotracheal intubation or use of supraglottic airway devices in the prehospital setting improves outcomes following out-of-hospital cardiac arrest (OHCA) compared with conventional bag-valve-mask ventilation.

Objective To test the hypothesis that prehospital advanced airway management is associated with favorable outcome after adult OHCA.

Design, Setting, and Participants Prospective, nationwide, population-based study (All-Japan Utstein Registry) involving 649 654 consecutive adult patients in Japan who had an OHCA and in whom resuscitation was attempted by emergency responders with subsequent transport to medical institutions from January 2005 through December 2010.

Main Outcome Measures Favorable neurological outcome 1 month after an OHCA, defined as cerebral performance category 1 or 2.

Results Of the eligible 649 359 patients with OHCA, 367 837 (57%) underwent bag-valve-mask ventilation and 281 522 (43%) advanced airway management, including 41 972 (6%) with endotracheal intubation and 239 550 (37%) with use of supraglottic airways. In the full cohort, the advanced airway group incurred a lower rate of favorable neurological outcome compared with the bag-valve-mask group (1.1% vs 2.9%; odds ratio [OR], 0.38; 95% CI, 0.36-0.39). In multivariable logistic regression, advanced airway management had an OR for favorable neurological outcome of 0.38 (95% CI, 0.37-0.40) after adjusting for age, sex, etiology of arrest, first documented rhythm, witnessed status, type of bystander cardiopulmonary resuscitation, use of public access automated external defibrillator, epinephrine administration, and time intervals. Similarly, the odds of neurologically favorable survival were significantly lower both for endotracheal intubation (adjusted OR, 0.41; 95% CI, 0.37-0.45) and for supraglottic airways (adjusted OR, 0.38; 95% CI, 0.36-0.40). In a propensity score–matched cohort (357 228 patients), the adjusted odds of neurologically favorable survival were significantly lower both for endotracheal intubation (adjusted OR, 0.45; 95% CI, 0.37-0.55) and for use of supraglottic airways (adjusted OR, 0.36; 95% CI, 0.33-0.39). Both endotracheal intubation and use of supraglottic airways were similarly associated with decreased odds of neurologically favorable survival.

Conclusion and Relevance Among adult patients with OHCA, any type of advanced airway management was independently associated with decreased odds of neurologically favorable survival compared with conventional bag-valve-mask ventilation.

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Echo for cardiac arrest outcome prediction

A meta-analysis of studies evaluation transthoracic echo as a means of predicting return of spontaneous circulation in cardiac arrest (ROSC) provides some likelihood ratios to what we already know: absence of sonographic cardiac activity means a very low chance of ROSC.

The authors report a pooled negative LR of 0.18 (95% CI = 0.10 to 0.31), and a positive likelihood ratio of 4.26 (95% CI = 2.63 to 6.92).

They conclude that focused transthoracic echo is a fairly effective (although not definitive) test for predicting death if no cardiac activity is noted during resuscitation, and recommend interpreting the echo in the light of the test characteristics and the clinical pre-test probability, as one should do for all imaging investigations:


“An elderly patient with an unwitnessed cardiac arrest already has very poor odds for survival. Confirmation of asystole on echo lowers those pretest odds by a factor of 5.6 and therefore might lead to termination of resuscitation. However, in the case of a 50-year-old rescued from drowning, detection of cardiac contractility on echo would increase his already fair odds of survival by a factor of 4.3, prompting continued aggressive resuscitation.”

Only five relatively small studies contributed to the findings. A more definitive answer to this question should be provided in the future by the multi-centre REASON 1 trial.

Objectives:  The objective was to determine if focused transthoracic echocardiography (echo) can be used during resuscitation to predict the outcome of cardiac arrest.

Methods:  A literature search of diagnostic accuracy studies was conducted using MEDLINE via PubMed, EMBASE, CINAHL, and Cochrane Library databases. A hand search of references was performed and experts in the field were contacted. Studies were included for further appraisal and analysis only if the selection criteria and reference standards were met. The eligible studies were appraised and scored by two independent reviewers using a modified quality assessment tool for diagnostic accuracy studies (QUADAS) to select the papers included in the meta-analysis.

Results:  The initial search returned 2,538 unique papers, 11 of which were determined to be relevant after screening criteria were applied by two independent researchers. One additional study was identified after the initial search, totaling 12 studies to be included in our final analysis. The total number of patients in these studies was 568, all of whom had echo during resuscitation efforts to determine the presence or absence of kinetic cardiac activity and were followed up to determine return of spontaneous circulation (ROSC). Meta-analysis of the data showed that as a predictor of ROSC during cardiac arrest, echo had a pooled sensitivity of 91.6% (95% confidence interval [CI] = 84.6% to 96.1%), and specificity was 80.0% (95% CI = 76.1% to 83.6%). The positive likelihood ratio for ROSC was 4.26 (95% CI = 2.63 to 6.92), and negative likelihood ratio was 0.18 (95% CI = 0.10 to 0.31). Heterogeneity of the results (sensitivity) was nonsignificant (Cochran’s Q: χ(2) = 10.63, p = 0.16, and I(2) = 34.1%).

Conclusions:  Echocardiography performed during cardiac arrest that demonstrates an absence of cardiac activity harbors a significantly lower (but not zero) likelihood that a patient will experience ROSC. In selected patients with a higher likelihood of survival from cardiac arrest at presentation, based on established predictors of survival, echo should not be the sole basis for the decision to cease resuscitative efforts. Echo should continue to be used only as an adjunct to clinical assessment in predicting the outcome of resuscitation for cardiac arrest.

Bedside Focused Echocardiography as Predictor of Survival in Cardiac Arrest Patients: A Systematic Review
Acad Emerg Med. 2012 Oct;19(10):1119-1126

ECMO for paediatric cardiac arrest

The Taiwanese are at it again with their extracorporeal life support. This time, they report their outcomes in children who received ECMO for in-hospital cardiac arrest. Interestingly, the patients with pure cardiac causes of cardiac arrest had a survival rate similar to patients with non-cardiac causes.


PURPOSE: The study aims to describe 11 years of experience with extracorporeal cardiopulmonary resuscitation (ECPR) for in-hospital paediatric cardiac arrest in a university affiliated tertiary care hospital.

METHODS: Paediatric patients who received extracorporeal membrane oxygenation (ECMO) during active extracorporeal cardiopulmonary resuscitation (ECPR) at our centre from 1999 to 2009 were included in this retrospective study. The results from three different cohorts (1999-2001, 2002-2005 and 2006-2009) were compared. Survival rates and neurological outcomes were analysed. Favourable neurological outcome was defined as paediatric cerebral performance categories (PCPC) 1, 2 and 3.

RESULTS: We identified 54 ECPR events. The survival rate to hospital discharge was 46% (25/54), and 21 (84%) of the survivors had favourable neurological outcomes. The duration of CPR was 39±17 min in the survivors and 52±45 min in the non-survivors (p=NS). The patients with pure cardiac causes of cardiac arrest had a survival rate similar to patients with non-cardiac causes (47% (18/38) vs. 44% (7/16), p=NS). The non-survivors had higher serum lactate levels prior to ECPR (13.4±6.4 vs. 8.8±5.1 mmol/L, p<0.01) and more renal failure after ECPR (66% (19/29) vs. 20% (5/25), p<0.01). The patients resuscitated between 2006 and 2009 had shorter durations of CPR (34±13 vs. 78±76 min, p=0.032) and higher rates of survival (55% (16/29) vs. 0% (0/8), p=0.017) than those resuscitated between 1999 and 2002.

CONCLUSIONS: In our single-centre experience with ECPR for paediatric in-hospital cardiac arrest, the duration of CPR has become shorter and outcomes have improved in recent years. Higher pre-ECPR lactate levels and the presence of post-ECPR renal failure were associated with increased mortality. The presence of non-cardiac causes of cardiac arrest did not preclude successful ECPR outcomes. The duration of CPR was not significantly associated with poor outcomes in this study.

Eleven years of experience with extracorporeal cardiopulmonary resuscitation for paediatric patients with in-hospital cardiac arrest
Resuscitation. 2012 Jun;83(6):710-4

Extracorporeal cardiopulmonary resuscitation

You have a patient in cardiac arrest who has had excellent resuscitation from the point of collapse, and who has treatable underlying pathology (eg. PE or STEMI). However you’re unable to get return of spontaneous circulation so you call it. Someone just died for whom the technology exists to save them. Extracorporeal life support (ECLS) supports heart and lung function by externally providing circulatory flow and gas exchange until the patient’s underlying cause of arrest is treated or recovers.
ECLS requires an extracorporeal membrane oxygenation (ECMO) circuit to be placed during the cardiac arrest resuscitation. This may sound like extreme stuff, but there have been some amazing saves with this technology, and large numbers of in-hospital and out-of-hospital arrest patients have been treated in Japan, Korea, and Taiwan. ECMO has even been commenced in the field by prehospital emergency physicians.
An inspiring EMCrit podcast with Dr Joe Bellezzo described how this technology is applied at Sharp Memorial Hospital in San Diego. Bellezzo and colleagues have now published a series of their out-of-hospital arrest cases who received ECLS initiated by emergency physicians(1).
Coming back to the Japanese, a multicentre prospective cohort study of ECLS for out-of hospital cardiac arrest (the ‘SAVE-J’ study) selected patients with VF or pulseless VT in whom no ROSC was achieved with standard resuscitative measures. Their striking results mirror other ECLS studies and were published in abstract form in November 2011(2).
To me, the overwhelming take home messages from what I’ve seen and read on this are:


1. ECLS can provide dramatic saves with neurologically intact survival in cardiac arrest cases that otherwise would be dead.

2. The critical factor for successful clinical outcomes and avoidance of wasted resources and clinical futility is case selection. The underlying cause of arrest needs to be reversible (eg. myocarditis) or treatable (eg. STEMI) and good resuscitation needs to have been in place prior to ECLS.

3. In the right hospital with the right resuscitation team, it can be done.

1. Emergency physician-initiated extracorporeal cardiopulmonary resuscitation
Resuscitation. 2012 Aug;83(8):966-70
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CONTEXT: Extracorporeal cardiopulmonary resuscitation (ECPR) refers to emergent percutaneous veno-arterial cardiopulmonary bypass to stabilize and provide temporary support of patients who suffer cardiopulmonary arrest. Initiation of ECPR by emergency physicians with meaningful long-term patient survival has not been demonstrated.

OBJECTIVE: To determine whether emergency physicians could successfully incorporate ECPR into the resuscitation of patients who present to the emergency department (ED) with cardiopulmonary collapse refractory to traditional resuscitative efforts.

DESIGN: A three-stage algorithm was developed for ED ECPR in patients meeting inclusion/exclusion criteria. We report a case series describing our experience with this algorithm over a 1-year period.

RESULTS: 42 patients presented to our ED with cardiopulmonary collapse over the 1-year study period. Of these, 18 patients met inclusion/exclusion criteria for the algorithm. 8 patients were admitted to the hospital after successful ED ECPR and 5 of those patients survived to hospital discharge neurologically intact. 10 patients were not started on bypass support because either their clinical conditions improved or resuscitative efforts were terminated.

CONCLUSION: Emergency physicians can successfully incorporate ED ECPR in the resuscitation of patients who suffer acute cardiopulmonary collapse. More studies are necessary to determine the true efficacy of this therapy.

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2. Multicenter Non-Randomized Prospective Cohort Study of Extracorporeal Cardiopulmonary Resuscitation for Out-of Hospital Cardiac Arrest: Study of Advanced Life Support for Ventricular Fibrillation with Extracorporeal Circulation in Japan (SAVE-J)
Circulation 2011; 124: A18132
[EXPAND Click for abstract]


Background: This study is aimed to examine the efficacy of extracorporeal cardiopulmonary resuscitation (ECPR) for patients in out-of hospital cardiac arrest (OHCA) with ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT).

Method: The design of this study is a multicenter non-randomized prospective cohort study. Hypothesis is that the outcome of OHCA with VF or pulseless VT is similar between ECPR and conventional advanced life support (ALS). During from Oct. 2008 to Dec. 2010, forty six tertiary emergency hospitals were participated in this study. Patient inclusion criteria were 1) VF or pulseless VT on scene, 2) cardiac arrest on arrival at hospital, 3) within 45 minutes from a call to an arrival of hospital, and 4) non-ROSC by conventional ALS during 15 minutes after an arrival at hospital. Exclusion criteria were 1) age: 75 yr, 2) poor activities of daily livings, 3) non-cardiac verified cardiac arrest, and 4) hypothermia. According to the inclusion criteria, ECPR was adopted for OHCA in 26 hospitals (ECPR group) and conventional ALS was planned in 20 hospitals (non-ECPR group). Both groups (Intention-to-treat) were analyzed about the proportion of patients with favorable outcome (CPC1 or 2) assessed with the Glasgow-Pittsburgh Cerebral Performance and Overall Performance Categories at 1 month by chi square test and Fisher exact probability test.

Results: One hundred and eighty patients of ECPR group and 134 patients of non-ECPR group were enrolled. There was no difference between the background of ECPR group and non-ECPR group; Average age (56.0 VS 56.9), Witnessed (72.8% VS 75.4%), Lay-rescuer CPR (49.4% VS 45.5%), Acute coronary syndrome (65.6% VS 61.4%), Minutes from collapse to emergency department (26.8 VS 30.0). The favorable outcome rate in ECPR group (12.4%, 22 patients) was statistically higher than the rate in non-ECPR group (1.6%, two patients) (p<0.001).

Conclusion: Extracorporeal cardiopulmonary resuscitation may improve the outcome of out-of hospital cardiac arrest with VF or pulseless VT without ROSC by conventional ALS during 15 minutes after an arrival at hospital.

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Hypothermia after long down times

You receive a patient resuscitated from cardiac arrest to a perfusing rhythm in your emergency department. History suggests a long ‘down time’: There was a ten minute duration of ‘no-flow’ (time from collapse to the start of resuscitation attempts).
Would this make you more likely or less likely to initiate targeted temperature management (TTM) and cool the patient to the recommended 32-34 degrees?
A recent study supports the suggestion that a longer no-flow time is associated with greater odds of survival with TTM compared with no TTM, than patients with shorter no-flow times. In other words, cooling the patient is more likely to make a difference in the ‘long down time’ patient, even though the overall survival in that group is obviously less.


Aim Mild therapeutic hypothermia has shown to improve long-time survival as well as favorable functional outcome after cardiac arrest. Animal models suggest that ischemic durations beyond 8 min results in progressively worse neurologic deficits. Based on these considerations, it would be obvious that cardiac arrest survivors would benefit most from mild therapeutic hypothermia if they have reached a complete circulatory standstill of more than 8 min.

Methods In this retrospective cohort study we included cardiac arrest survivors of 18 years of age or older suffering a witnessed out-of-hospital cardiac arrest, which remain comatose after restoration of spontaneous circulation. Data were collected from 1992 to 2010. We investigated the interaction of ‘no-flow’ time on the association between post arrest mild therapeutic hypothermia and good neurological outcome. ‘No-flow’ time was categorized into time quartiles (0, 1–2, 3–8, >8 min).

Results One thousand-two-hundred patients were analyzed. Hypothermia was induced in 598 patients. In spite of showing a statistically significant improvement in favorable neurologic outcome in all patients treated with mild therapeutic hypothermia (odds ratio [OR]: 1.49; 95% confidence interval [CI]: 1.14–1.93) this effect varies with ‘no-flow’ time. The effect is significant in patients with ‘no-flow’ times of more than 2 min (OR: 2.72; CI: 1.35–5.48) with the maximum benefit in those with ‘no-flow’ times beyond 8 min (OR: 6.15; CI: 2.23–16.99).

Conclusion The beneficial effect of mild therapeutic hypothermia increases with cumulative time of complete circulatory standstill in patients with witnessed out-of-hospital cardiac arrest.

The beneficial effect of mild therapeutic hypothermia depends on the time of complete circulatory standstill in patients with cardiac arrest
Resuscitation. 2012 May;83(5):596-601

Don't ignore the diastolic

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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Confidential stuff – in hospital cardiac arrests

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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Nonshockable arrest survival improves with uninterrupted compressions

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

End-Tidal CO2 as a Predictor of Cardiac Arrest Survival



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

In CPR depth is good, but how deep to compress?

Some defibrillators have accelerometers capable of measuring chest compression depth during CPR. This allowed a study correlating compression depth with survival in out of hospital cardiac arrest.
More than half of patients received less than the 2005 recommended chest compression depth of 38–51 mm and >90% received less than the 2010 recommended depth of >50 mm. There was an inverse relationship between rate and depth, ie. rescuers had a tendency to ‘push hard, push slow’ or ‘push soft, push fast’.
The authors state:
We found an association between adequate compression depth and good outcomes but could not demonstrate that the 2010 recommendations are better than those from 2005. Although we believe that compression depth is an important component of CPR and should be measured routinely during cardiac arrest resuscitation, we believe that the optimal depth is currently unknown.


BACKGROUND: The 2010 international guidelines for cardiopulmonary resuscitation recently recommended an increase in the minimum compression depth from 38 to 50 mm, although there are limited human data to support this. We sought to study patterns of cardiopulmonary resuscitation compression depth and their associations with patient outcomes in out-of-hospital cardiac arrest cases treated by the 2005 guideline standards.

DESIGN: Prospective cohort.

SETTING: Seven U.S. and Canadian urban regions.

PATIENTS: We studied emergency medical services treated out-of-hospital cardiac arrest patients from the Resuscitation Outcomes Consortium Epistry-Cardiac Arrest for whom electronic cardiopulmonary resuscitation compression depth data were available, from May 2006 to June 2009.

MEASUREMENTS: We calculated anterior chest wall depression in millimeters and the period of active cardiopulmonary resuscitation (chest compression fraction) for each minute of cardiopulmonary resuscitation. We controlled for covariates including compression rate and calculated adjusted odds ratios for any return of spontaneous circulation, 1-day survival, and hospital discharge.

MAIN RESULTS: We included 1029 adult patients from seven U.S. and Canadian cities with the following characteristics: Mean age 68 yrs; male 62%; bystander witnessed 40%; bystander cardiopulmonary resuscitation 37%; initial rhythms: Ventricular fibrillation/ventricular tachycardia 24%, pulseless electrical activity 16%, asystole 48%, other nonshockable 12%; outcomes: Return of spontaneous circulation 26%, 1-day survival 18%, discharge 5%. For all patients, median compression rate was 106 per minute, median compression fraction 0.65, and median compression depth 37.3 mm with 52.8% of cases having depth <38 mm and 91.6% having depth <50 mm. We found an inverse association between depth and compression rate ( p < .001). Adjusted odds ratios for all depth measures (mean values, categories, and range) showed strong trends toward better outcomes with increased depth for all three survival measures.
CONCLUSIONS: We found suboptimal compression depth in half of patients by 2005 guideline standards and almost all by 2010 standards as well as an inverse association between compression depth and rate. We found a strong association between survival outcomes and increased compression depth but no clear evidence to support or refute the 2010 recommendations of >50 mm. Although compression depth is an important component of cardiopulmonary resuscitation and should be measured routinely, the most effective depth is currently unknown.

What is the role of chest compression depth during out-of-hospital cardiac arrest resuscitation?
Crit Care Med. 2012 Apr;40(4):1192-8