Early prognostic indices after cardiopulmonary resuscitation (CPR). The Cerebral Resuscitation Study Group

Clinical Predictive Models of Sudden Cardiac Arrest: A Survey of the Current Science and Analysis of Model Performances

Background

More than 500 000 sudden cardiac arrests (SCAs) occur annually in the United States. Clinical predictive models (CPMs) may be helpful tools to differentiate between patients who are likely to survive or have good neurologic recovery and those who are not. However, which CPMs are most reliable for discriminating between outcomes in SCA is not known.

Methods and Results

We performed a systematic review of the literature using the Tufts PACE (Predictive Analytics and Comparative Effectiveness) CPM Registry through February 1, 2020, and identified 81 unique CPMs of SCA and 62 subsequent external validation studies. Initial cardiac rhythm, age, and duration of cardiopulmonary resuscitation were the 3 most commonly used predictive variables. Only 33 of the 81 novel SCA CPMs (41%) were validated at least once. Of 81 novel SCA CPMs, 56 (69%) and 61 of 62 validation studies (98%) reported discrimination, with median c‐statistics of 0.84 and 0.81, respectively. Calibration was reported in only 29 of 62 validation studies (41.9%). For those novel models that both reported discrimination and were validated (26 models), the median percentage change in discrimination was −1.6%. We identified 3 CPMs that had undergone at least 3 external validation studies: the out‐of‐hospital cardiac arrest score (9 validations; median c‐statistic, 0.79), the cardiac arrest hospital prognosis score (6 validations; median c‐statistic, 0.83), and the good outcome following attempted resuscitation score (6 validations; median c‐statistic, 0.76).

Conclusions

Although only a small number of SCA CPMs have been rigorously validated, the ones that have been demonstrate good discrimination.

Spontaneous swallowing occurs during autoresuscitation in the in situ brainstem preparation of rat

Previous studies report that upper airway reflexes are operational during autoresuscitation from respiratory arrest. We investigated swallowing/breathing interactions, measured by recording of vagal (VNA) and phrenic nerve activities (PNA), during autoresuscitation in the in situ perfused brainstem preparation of juvenile rats. During the initial surgery, respiratory arrest was induced by exsanguination and cooling. Reperfusion (i.e. re-oxygenation and re-warming) of the brainstem circuits was associated with frequent spontaneous swallowing before resumption of respiration (n=6, 'stage 1 autoresuscitation'). When recovered, the respiratory pattern was transiently apneustic-like ('stage 2 autoresuscitation'). Spontaneous swallowing often occurred at the end of the prolonged PNA (n=9/12). Successful autoresuscitation was characterised by re-establishment of the 3 phase respiratory motor pattern and no spontaneous swallowing. Pharmacological inhibition (isoguvacine, 10 mM, 50-75 nl; n=10) of the Kölliker-Fuse nucleus (KF) mimicked stage 2 autoresuscitation. However, the frequency of spontaneous swallowing after KF inhibition did not correlate with subsequent recovery of the eupneic respiratory motor pattern.

A prediction survival model for out-of-hospital cardiopulmonary resuscitations

AIMS

The aims of this study were to double check old (Resuscitation Predictor Scoring [RPS], Advanced Cardiac Life Support, and Early Prediction Score [EPS]) and form new (Serbian Quality of Life immediately [SR-QOLi], Serbian Quality of Life short-term [SR-QOLs], and Serbian Quality of Life long-term [SR-QOLl]) scores for survival prediction in out-of-hospital cardiopulmonary resuscitation (OHCPR) in Serbia.

METHODS

A prospective, 2-year, multicentric study was designed. By the means of the Utstein style, OHCPR performed and its outcome were followed. In every patient, immediate (i) (Return of Spontaneus Circulation [ROSC] >20 min), short-term (s) (to hospital discharge), and long-term [1] (1 year upon) survival after the OHCPR, under the application of RPS, ASCLS, and EPS models, was evaluated. We assessed the association between survival rate and individual predictors of OHCPR using RPS, ASCLS, and EPS: cardiopulmonary resuscitation (CPR) started (>4 or <4 minutes after out-of-hospital cardiac arrest), swallowing activity (present or not), the primary arrest mode (cardiac or respiratory), and initial pupillar photoreaction (present or absent). By the successive-logistic and linear-regression analysis method, the additional model of the type SR-QOL (SR-QOLi, SR-QOLs, and SR-QOLl) was created.

RESULTS

We found that bystander CPR, witnessed arrest, shockable rhythms, CPR within 4 minutes, pupillar photoreaction, and primary cardiac arrest mode were associated with improved survival. Cumulative survival upon OHCPR was 12.7% for immediate, 11.3% before patient's discharge, and 10% after 12 months. Applied on our sample, standard scores displayed satisfactory (RPS) and good (Advanced Cardiac Life Support and EPS) degree of survival prediction in OHCPR. In receiver operator characteristic (ROC) analysis, SR-QOLi (ROC = 0.833) and SR-QOLs (ROC = 0.882) were defined as a good models and SR-QOLl (ROC = 0.913) was defined as an excellent model for prediction of outpatient CPR outcomes.

CONCLUSION

In the course of the research, SR-QOL models were created for prediction of the immediate (SR-QOLi), short-term (SR-QOLs), and long-term (SR-QOLl) survival after the OHCPR, better predictions in our environment.

[What is the outcome of cardiac arrest survivors?]

In spite of recent advances, cardiac arrest remains a serious illness for which survival rate stays very low. If prehospital death remains the major problem, in-hospital death is also important. Two thirds of deaths in intensive care are the result of initial brain damage. After discharge, risk of recurrence for victims of sudden death is important and requires specific care and sometimes the implant of a cardiac defibrillator. In survivors, medium and long-term survival is satisfactory and close to that of patients with similar age and comorbidities that have not suffered cardiac arrest. The << minor >> cerebral sequels remain unknown and their impact on quality of life needs further attention.

Prolonged retention of awareness during cardiopulmonary resuscitation for asystolic cardiac arrest

OBJECTIVE

To describe high level of awareness in a patient undergoing cardiopulmonary resuscitation for an asystolic cardiac arrest and review the literature regarding this phenomenon.

METHODS

This is a case report of a patient admitted to the Intensive Care Unit who suffered an asystolic cardiac arrest. We reviewed MEDLINE using the terms "awareness," "consciousness," "cerebral perfusion," "sedation," "analgesia," "termination," "cessation," and "cardiopulmonary resuscitation."

RESULTS

A 57-year-old man with renal failure suffered asystolic cardiac arrest. He was awake and alert during cardiopulmonary resuscitation (CPR). Cardiac arrest was confirmed by echocardiogram and invasive arterial monitoring. He briskly localized and consistently followed simple commands while chest compressions were in progress before becoming unresponsive and dying after a 3-h resuscitative effort. No sedation/analgesia was used. There are few reports in the literature describing similar events.

CONCLUSION

It is possible to retain a high level of awareness following cardiac arrest, particularly with effective CPR. Recognition of this situation when it occurs allows appropriate decisions to be made regarding the use of sedation and the length of resuscitative efforts.

Hepatic portal venous gas associated with poor outcome in out-of-hospital cardiac arrest patients

OBJECTIVES

To determine the incidence of sonographic hepatic portal venous gas (HPVG) and to clarify the relationship between the presence of HPVG and clinical outcomes in patients with out-of-hospital cardiac arrest (OHCA).

METHODS

From April 2002 to January 2003, patients with non-traumatic OHCA were prospectively enrolled in a tertiary medical centre in Taipei, Taiwan. Emergency abdominal sonography during resuscitation was performed to detect the presence of HPVG within the first 10 min on arrival of the emergency department (ED).

RESULTS

HPVG was detected in 16 (36%) of the 44 patients enrolled in this study. The patients with HPVG were older (P = 0.039), their cardiac arrest was witnessed less frequently (P = 0.01), they received more prolonged resuscitation (P = 0.008), and needed more accumulated doses of adrenaline (epinephrine) (P = 0.002). These patients had a considerably lower incidence of return of spontaneous circulation (ROSC) (P < 0.001), less survival to hospital admission (P < 0.001), less 24 h survival (P < 0.001) and less survival to discharge (P = 0.036). In a multiple regression analysis, HPVG was noted as an independent factor negatively associated with ROSC.

CONCLUSION

HPVG is not uncommon in patients receiving resuscitation for OHCA and is associated with poor outcome in these patients.

A rule for early outcome classification of out-of-hospital cardiac arrest patients presenting with ventricular fibrillation

The aim of the study was to develop a scoring system for outcome classification at the start of prehospital first tier resuscitation for patients with cardiac arrest from ventricular fibrillation (VF). We studied a consecutive sample of 100 out-of-hospital cardiac arrest patients, presenting with VF of presumed cardiac etiology on arrival of the first tier (in a two-tiered urban Emergency Medical Services system). The number of patients discharged was 29 ('survivors') and 71 died ('non-survivors'). The electrocardiography (ECG) tracings recorded during resuscitation using a semi-automatic defibrillator were retrospectively analysed. For each patient, VF amplitude in mV (VF_a) and the number of base-line crossings per second (VF_blc) were calculated. Fisher's linear discriminant analysis was applied to discriminate between survivors and non-survivors using the variables VF_a, VF_blc and age. Patients were classed as potential survivors or non-survivors using a survival index = 0.6*(VF_a) + 0.4*(VF_blc)-4.0. If for a given patient the survival index is < 0, he is classified in the non-survivor group, if the survival index is > 0, he is classified in the survivor group. Using this index 79% of the survivors and 70% of the non-survivors could be classified correctly. Adding age to the formula increased the correct classification of survivors to 86 and 73% for the non-survivors. The survival index provides a research tool for the discrimination between potential survivors and non-survivors, which opens the possibility for the development of alternative treatment protocols in cardiac arrest.

Prediction of death and neurologic outcome in the emergency department in out-of-hospital cardiac arrest survivors

We reviewed the hospital records of 127 consecutive patients who were resuscitated from cardiac arrest in a retrospective cohort analysis. A cardiac arrest score utilizing time to return of spontaneous circulation, systolic blood pressure at the time of presentation, and initial neurologic exam were calculated. This score was analyzed with 39 other clinical variables for significance with regard to mortality or neurologic survival using multivariate analysis. Combining these variables into a cardiac arrest score (levels 0, 1, 2, 3, from least to most favorable) allowed prediction of neurologic outcomes and mortality from a single variable in an independent fashion (p < 0.0001). Logistic regression models found scores of 0, 1, 2, and 3 predicted in-hospital mortality rates of 90%, 71%, 42%, 18%, and neurologic recovery in 3%, 17%, 57%, and 89%, respectively. The cardiac arrest score was able to predict in-hospital mortality and neurologic outcomes in those who survived to emergency department arrival. This scoring scheme may aide in selection of patients for early aggressive measures, including triage coronary angiography and angioplasty.

Recommended guidelines for uniform reporting of pediatric advanced life support: the pediatric Utstein style

This statement is the product of a task force meeting held June 8, 1994, in Washington DC in conjunction with the First International Conference on Pediatric Resuscitation and a follow-up task force writing group meeting held September 18, 1994, in Chicago. Draft versions of the statement were circulated for comment to all members of the task force, the American Heart Association Subcommittee on Pediatric Resuscitation, and several outside reviewers. This statement and the International Conference on Pediatric Resuscitation were cosponsored by the American Academy of Pediatrics and the American Heart Association. The development of this statement was authorized by the American Academy of Pediatrics; the American Heart Association National Subcommittees on Pediatric Resuscitation, Basic Life Support, and Advanced Cardiac Life Support, the Committee on Emergency Cardiac Care, the Science Advisory Committee; and the European Resuscitation Council. In addition to the writing group, members of the Pediatric Utstein Task Force are Paul Anderson, M Douglas Baker, Jane Ball, Desmond Bohn, Dena Brownstein, J Michael Dean, Niranjan Kissoon, Bruce Klein, Patrick Malone, Karin McCloskey, James McCrory, P Pearl O'Rourke, Mary Patterson, Charles Schleien, James Seidel, Joseph J Tepas III, and Becky Yano.

Recommended guidelines for uniform reporting of pediatric advanced life support: the Pediatric Utstein Style. A statement for healthcare professionals from a task force of the American Academy of Pediatrics, the American Heart Association, and the European Resuscitation Council

This consensus document is an attempt to provide an organized method of reporting pediatric ALS data in out-of-hospital, emergency department, and in-hospital settings. For this methodology to gain wide acceptance, the task force encourages development of a common data set for both adult and pediatric ALS interventions. In addition, every effort should be made to ensure that consistent definitions are used in all age groups. As health care changes, we will all be challenged to document the effectiveness of what we currently do and show how new interventions or methods of treatment improve outcome and/or reduce cost. Only through collaborative research will we obtain the necessary data. For these reasons, and to improve the quality of care and patient outcomes, it is the hope of the task force that clinical researchers will follow the recommendations in this document. It is recognized that further refinements of this statement will be needed; these recommendations will improve only when researchers, clinicians, and EMS personnel use them, work with them, and modify them. Suggestions, recommendations, and other comments aimed at improving the reporting of pediatric resuscitation should be sent to Arno Zaritsky, MD, Eastern Virginia Medical School, Children's Hospital of The King's Daughter, Division of Critical Care Medicine, 601 Children's Lane, Norfolk, VA 23507.

Predicting death after CPR. Experience at a nonteaching community hospital with a full-time critical care staff

OBJECTIVE

To identify a series of variables which predict death after in-hospital cardiopulmonary resuscitation (CPR).

DESIGN

Retrospective observational study.

SETTING

A nonteaching community hospital with 24-hr on-site critical care specialists.

PATIENTS

Consecutive adults undergoing CPR between August 1989 and July 1991.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Two hundred forty-two patients suffered a total of 289 cardiopulmonary arrests. Forty patients (16.5%) survived to discharge. Thirty-nine (16%) patients had more than one cardiopulmonary arrest. Survival of second CPR was 18%. Acute physiology and chronic health evaluation (APACHE) II scores within 24 h of admission and CPR (APACHE[a] and APACHE[b]) were measured. APACHE(a) and (b) scores more than 20 had a 96% predictive value positive and were associated with a five-fold decrease in survival. Besides APACHE, cardiopulmonary arrests on medical floors and after day 4 of hospitalization, duration of CPR more than 15 min, and asystole assumed significance at multivariate levels for predicting death. Ventilatory assistance and Glasgow coma score of less than 9 at 24 h after CPR predicted death for initial survivors at multivariate levels. Survival on telemetry units were similar to the ICU (17 vs 21%) but twice that of the medical floors.

CONCLUSIONS

The CPR outcome can be predicted early during hospital course, which may assist physicians to formulate a do-not-resuscitate order. Patients surviving a CPR should be considered candidates for another resuscitation if clinically warranted. Low-risk patients can safely be admitted to telemetry units instead of to more costly ICUs.

Recommended guidelines for uniform reporting of pediatric advanced life support: the pediatric Utstein Style. A statement for healthcare professionals from a task force of the American Academy of Pediatrics, the American Heart Association, and the European Resuscitation Council. Writing Group

This consensus document is an attempt to provide an organized method of reporting pediatric ALS data in out-of-hospital, emergency department, and in-hospital settings. For this methodology to gain wide acceptance, the task force encourages development of a common data set for both adult and pediatric ALS interventions. In addition, every effort should be made to ensure that consistent definitions are used in all age groups. As health care changes, we will all be challenged to document the effectiveness of what we currently do and show how new interventions or methods of treatment improve outcome and/or reduce cost. Only through collaborative research will we obtain the necessary data. For these reasons, and to improve the quality of care and patient outcomes, it is the hope of the task force that clinical researchers will follow the recommendations in this document. It is recognized that further refinements of this statement will be needed; these recommendations will improve only when researchers, clinicians, and EMS personnel use them, work with them, and modify them. Suggestions, emendations, and other comments aimed at improving the reporting of pediatric resuscitation should be sent to Arno Zaritsky, MD, Eastern Virginia Medical School, Children's Hospital of the King's Daughter, Division of Critical Care Medicine, 601 Children's Lane, Norfolk, VA 23507.

Factors affecting outcome following cardiopulmonary resuscitation

Many patients who receive cardiopulmonary resuscitation (CPR) for cardiac arrest do not survive to leave hospital. Factors associated with adverse outcomes include unwitnessed cardiac arrest in general wards, particularly at night, prolonged resuscitation, asystole, associated disorders (e.g. sepsis, malignancy, renal failure, and left ventricular dysfunction), absent pupillary responses, hypoxaemia, low PetCO2 during resuscitation, and severe acid base imbalance. Outside hospitals, cardiac arrests result in more favourable outcomes if they occur at work, and bystander CPR and early defibrillation are initiated. On admission to ICU, likely predictors of death or severe neurological disability include prolonged coma, impaired brainstem reflexes, and persistent convulsions. Experience with cerebrospinal fluid enzymes and electrophysiological measurements is limited. Multivariate scoring systems are not sufficiently reliable. The importance of hyperglycaemia, the required level of CPR training, and the appropriateness of responding to some cases, remain debatable.

Early prediction of non-survival for patients suffering cardiac arrest--a word of caution. The Belgian Cerebral Resuscitation Study Group

A total of 6178 persons with out-of-hospital (70%) and in hospital (30%) cardiac arrests from the first of January 1982 until the end of 1989 were reviewed retrospectively with respect to 4 variables, contributing to a score for specific prediction of poor prognosis (cut-off point: greater than 3 points). These included age, initial ECG, type of respiratory arrest and bystander resuscitation. Presence of ventricular fibrillation, gasping and bystander resuscitation contributes nothing to the score, while presence of asystole or EMD (electromechanical dissociation), apnoea and absence of bystander resuscitation adds one point to it. Of patients scoring 4 or 5 points 44 were awake 14 days post CPR (Class 3). The positive predictive value of the score was 97% (95% CI 96-98%) for the out-of-hospital group and 92.2% (95% CI 88-95%) for the in-hospital group. The specificity was respectively 92.3% (95% CI 89-95%) and 94.2% (95% CI 91-96%). Although the score can weigh the likelihood of no success against that of success, we cannot recommend it for decision making as far as abandoning or continuing cardiopulmonary resuscitation efforts.