Survival Prediction of Initial Blood pH for Nontraumatic Out-of-hospital Cardiac Arrest Patients in the Emergency Department

Intra-arrest blood-based biomarkers for out-of-hospital cardiac arrest: A scoping review

Objective

Blood-based biomarkers play a central role in the diagnosis and treatment of critically ill patients, yet none are routinely measured during the intra-arrest phase of out-of-hospital cardiac arrest (OHCA). Our objective was to describe methodological aspects, sources of evidence, and gaps in research surrounding intra-arrest blood-based biomarkers for OHCA.

Methods

We used scoping review methodology to summarize existing literature. The protocol was designed a priori following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Extension for Scoping Reviews. Inclusion criteria were peer-reviewed scientific studies on OHCA patients with at least one blood draw intra-arrest. We excluded in-hospital cardiac arrest and animal studies. There were no language, date, or study design exclusions. We conducted an electronic literature search using PubMed and Embase and hand-searched secondary literature. Data charting/synthesis were performed in duplicate using standardized data extraction templates.

Results

The search strategy identified 11,834 records, with 118 studies evaluating 105 blood-based biomarkers included. Only eight studies (7%) had complete reporting. The median number of studies per biomarker was 2 (interquartile range 1-4). Most studies were conducted in Asia (63 studies, 53%).  Only 22 studies (19%) had blood samples collected in the prehospital setting, and only six studies (5%) had samples collected by paramedics. Pediatric patients were included in only three studies (3%). Out of eight predefined biomarker categories of use, only two were routinely assessed: prognostic (97/105, 92%) and diagnostic (61/105, 58%).

Conclusions

Despite a large body of literature on intra-arrest blood-based biomarkers for OHCA, gaps in methodology and knowledge are widespread.

Emergency thoracotomies in traumatic cardiac arrests following blunt trauma - experiences from a German level I trauma center

PURPOSE

Resuscitative thoracotomies (RT) are the last resort to reduce mortality in patients suffering severe trauma. In recent years, indications for RT have been extended from penetrating to blunt trauma. However, discussions on efficacy are still ongoing, as data on this rarely performed procedure are often scarce. Therefore, this study analyzed RT approaches, intraoperative findings, and clinical outcome measures following RT in patients with cardiac arrest following blunt trauma.

METHODS

All patients admitted to our level I trauma center's emergency room (ER) who underwent RT between 2010 and 2021 were retrospectively analyzed. Retrospective chart reviews were performed for clinical data, laboratory values, injuries observed during RT, and surgical procedures. Additionally, autopsy protocols were assessed to describe injury patterns accurately.

RESULTS

Fifteen patients were included in this study with a median ISS of 57 (IQR 41-75). The 24-h survival rate was 20%, and the total survival rate was 7%. Three approaches were used to expose the thorax: Anterolateral thoracotomy, clamshell thoracotomy, and sternotomy. A wide variety of injuries were detected, which required complex surgical interventions. These included aortic cross-clamping, myocardial suture repairs, and pulmonary lobe resections.

CONCLUSION

Blunt trauma often results in severe injuries in various body regions. Therefore, potential injuries and corresponding surgical interventions must be known when performing RT. However, the chances of survival following RT in traumatic cardiac arrest cases following blunt trauma are small.

Survival with Good Neurological Outcome despite Prolonged Cardiopulmonary Resuscitation and Extreme Acidosis after Out-of-Hospital Cardiac Arrest Due to Acute Myocardial Infarction: A Case Report and Review of the Literature

We report the case of a 49-year-old male who suffered from a myocardial infarction with subsequent cardiac arrest. The emergency medical team began cardiopulmonary resuscitation, including defibrillation of ventricular fibrillation. Although a return of spontaneous circulation was achieved after approximately 30 min of continued efforts, the patient went back into cardiac arrest on the way to the hospital and resuscitation had to be resumed. On admission, the patient was severely acidotic with a pH of 6.67, lactatemia of 19 mmol/L, and pronounced hypercapnia (pCO₂ 127 mmHg). Despite the poor prognosis, all possible efforts including coronary intervention and therapeutic hypothermia were carried out and the patient made a quick recovery with discharge from the intensive care unit on day 5. Survival of extreme acidosis, such as in this case, is rare. This is the first report of survival with good neurologic outcome in a patient with myocardial infarction, cardiac arrest, and pH of under 6.7 on admission at the clinic.

Recovery from profound acidosis (pH 6.685) in multi-organ dysfunction syndrome

Acidosis is a common feature of patients referred to critical care from the emergency department. We present the case of a 49-year-old female with multi-organ dysfunction syndrome (MODS) and an arterial pH of 6.685 on arrival to the emergency department. This case is unique as the patient was in circulatory shock with MODS from rhabdomyolysis on arrival and had not suffered a cardiac arrest. We believe this to be the first reported case of full recovery from such an extreme metabolic disturbance in this context, and discuss the relevance of profound acidosis to early clinical decision-making.

Severe metabolic acidosis after out-of-hospital cardiac arrest: risk factors and association with outcome

BACKGROUND

Metabolic acidosis is frequently observed as a consequence of global ischemia-reperfusion after out-of-hospital cardiac arrest (OHCA). We aimed to identify risk factors and assess the impact of metabolic acidosis on outcome after OHCA.

METHODS

We included all consecutive OHCA patients admitted between 2007 and 2012. Using admission data, metabolic acidosis was defined by a positive base deficit and was categorized by quartiles. Main outcome was survival at ICU discharge. Factors associated with acidosis severity and with main outcome were evaluated by linear and logistic regressions, respectively.

RESULTS

A total of 826 patients (68.3% male, median age 61 years) were included in the analysis. Median base deficit was 8.8 [5.3, 13.2] mEq/l. Male gender (p = 0.002), resuscitation duration (p < 0.001), initial shockable rhythm (p < 0.001) and post-resuscitation shock (p < 0.001) were associated with an increased level of acidosis. ICU mortality rate increased across base deficit quartiles (39.1, 59.2, 76.3 and 88.3%, p for trend < 0.001), and base deficit was independently associated with ICU mortality (p < 0.001). The proportion of CPC 1 patients among ICU survivors was similar across base deficit quartiles (72.8, 67.1, 70.5 and 62.5%, p = 0.21), and 7.3% of patients with a base deficit higher than 13.2 mEq/l survived to ICU discharge with complete neurological recovery.

CONCLUSION

Severe metabolic acidosis is frequent in OHCA patients and is associated with poorer outcome, in particular due to refractory shock. However, we observed that about 7% of patients with a very severe metabolic acidosis survived to ICU discharge with complete neurological recovery.

[Which patients benefit from transport with ongoing cardiopulmonary resuscitation? : Retrospective analysis of 70 patients with refractory preclinical cardiac arrest]

BACKGROUND

Mortality in patients with out-of-hospital cardiac arrest (OHCA) remains very high despite advances in resuscitation algorithms. Most of these patients die at the scene and do not reach hospital. It is currently the subject of discussion whether transport to hospital with ongoing cardiopulmonary resuscitation (CPR) improves survival and neurological outcome in patients with OHCA.

OBJECTIVE

The aim of this study was to identify predictors of survival and good neurological outcome in patients after OHCA who were transported to hospital with ongoing CPR.

PATIENTS AND METHODS

A total of 70 consecutive patients with refractory OHCA (mean age 54.7 ± 15 years) transported to hospital with ongoing CPR were retrospectively analyzed. Neurological outcome was assessed after 30 days based on the Glasgow-Pittsburgh cerebral performance category (CPC).

RESULTS

After 30 days 82.9% of the patients enrolled in the trial died (CPC score of 5), 8 patients (11.4%) showed a good neurological recovery with CPC scores of 1-2 and 4 patients (5.7%) had a poor neurological outcome with CPC scores of 3-4. Predictors of good neurological outcome were witnessed arrest, initial defibrillatable rhythm and serum lactate levels on admission. In all patients with good outcome, the index event for OHCA was from cardiac causes.

CONCLUSION

Selected patient collectives can benefit from transport to hospital with ongoing cardiopulmonary resuscitation (CPR).