Point-of-care laboratory analyses of intraosseous, arterial and central venous samples during experimental cardiopulmonary resuscitation

Effect of other venous access on cardiopulmonary resuscitation quality: A prospective, randomized, controlled trial

This randomized controlled study aimed to prospectively evaluate the application effects of other venous access in patients undergoing cardiopulmonary resuscitation. A total of 212 patients who underwent respiratory and cardiac arrest were randomly divided into peripheral intravenous (IV) access group (IV group, n = 69), femoral vein catheterization group (FVC group, n = 72), and internal jugular vein catheterization group (IJVC group, n = 71). The puncture time, first administration time, pressure interruption time caused by the establishment of fluid pathway, endotracheal intubation time, complications, ROSC time, and ETCO2 were recorded. The time of establishing venous access was: IVIJVC>IV, P = 0.04). There was no significant difference in EtCO2 between the FVC, IV group, and IJVC group (PVC>IJVC>IV, P = 0.17). Due to catheterization, the time of suspending chest compression in the FVC group was significantly lower than in the IJVC group (5s vs. 12s). The time of establishing an artificial airway in the IV (38s) and FVC (35s) group were significantly longer than that in IJVC (52s) group. Central venous catheterization is more effective than peripheral venous catheterization in cardiopulmonary resuscitation. Moreover, femoral vein access was more effective than internal jugular vein access.

Serial paired arterial and jugular venous point-of-care values in dogs undergoing manual basic life support

OBJECTIVE

To evaluate differences in point-of-care (POC) variables obtained from arterial and jugular venous blood in dogs undergoing manual basic life support (BLS) and report changes over time.

DESIGN

Experimental study.

SETTING

Small animal research facility.

ANIMALS

Twenty-four purpose-bred research dogs.

INTERVENTIONS

Dogs were anesthetized, and arterial catheters were placed before euthanasia. One minute after cardiopulmonary arrest, BLS consisting of manual chest compressions and ventilation delivered via endotracheal intubation, face mask, mouth-to-nose, or no ventilation was initiated. Paired arterial and jugular venous blood samples were obtained for POC testing before euthanasia (T0), at 3 minutes (T3), and at 6 minutes (T6) into BLS.

MEASUREMENTS AND MAIN RESULTS

The association of POC variables with arterial or venous sample type while controlling for type of ventilation and sampling timepoint was determined using a generalized linear mixed model. Variables obtained from arterial and venous blood samples were compared over time using repeated measures ANOVA or Friedman test. Pao2, anion gap, potassium, chloride, glucose concentration, and PCV were significantly higher in arterial blood samples compared with venous samples (P < 0.03). By T6, arterial glucose concentration, arterial and venous base excess, venous pH, and plasma lactate, potassium, creatinine, bicarbonate, and sodium concentrations were significantly increased, and arterial and venous Po2, ionized calcium concentration, PCV, and total plasma protein concentration were significantly decreased from T0 (P < 0.05).

CONCLUSIONS

Although statistically significant, arteriovenous differences and changes in POC blood variables during BLS were small and not clinically relevant over time. Given the challenges of arterial blood sampling, it may be reasonable to pursue venous blood sampling during CPR. Further studies in dogs undergoing BLS and advanced life support are needed to better understand the potential clinical role of POC testing during CPR.

Dysnatremia at ICU admission and functional outcome of cardiac arrest: insights from four randomised controlled trials

PURPOSE

To evaluate the potential association between early dysnatremia and 6-month functional outcome after cardiac arrest.

METHODS

We pooled data from four randomised clinical trials in post-cardiac-arrest patients admitted to the ICU with coma after stable return of spontaneous circulation (ROSC). Admission natremia was categorised as normal (135-145 mmol/L), low, or high. We analysed associations between natremia category and Cerebral Performance Category (CPC) 1 or 2 at 6 months, with and without adjustment on the modified Cardiac Arrest Hospital Prognosis Score (mCAHP).

RESULTS

We included 1163 patients (581 from HYPERION, 352 from TTH48, 120 from COMACARE, and 110 from Xe-HYPOTHECA) with a mean age of 63 ± 13 years and a predominance of males (72.5%). A cardiac cause was identified in 63.6% of cases. Median time from collapse to ROSC was 20 [15-29] minutes. Overall, mean natremia on ICU admission was 137.5 ± 4.7 mmol/L; 211 (18.6%) and 31 (2.7%) patients had hyponatremia and hypernatremia, respectively. By univariate analysis, CPC 1 or 2 at 6 months was significantly less common in the group with hyponatremia (50/211 [24%] vs. 363/893 [41%]; P = 0.001); the mCAHP-adjusted odds ratio was 0.45 (95%CI 0.26-0.79, p = 0.005). The number of patients with hypernatremia was too small for a meaningful multivariable analysis.

CONCLUSIONS

Early hyponatremia was common in patients with ROSC after cardiac arrest and was associated with a poorer 6-month functional outcome. The mechanisms underlying this association remain to be elucidated in order to determine whether interventions targeting hyponatremia are worth investigating. Registration ClinicalTrial.gov, NCT01994772, November 2013, 21.

Differential diagnosis and cause-specific treatment during out-of-hospital cardiac arrest: a retrospective descriptive study

BACKGROUND

The cardiopulmonary resuscitation (CPR) guidelines recommend identifying and correcting the underlying reversible causes of out-of-hospital cardiac arrest (OHCA). However, it is uncertain how often these causes can be identified and treated. Our aim was to estimate the frequency of point of care ultrasound examinations, blood sample analyses and cause-specific treatments during OHCA.

METHODS

We performed a retrospective study in a physician-staffed helicopter emergency medical service (HEMS) unit. Data on 549 non-traumatic OHCA patients who were undergoing CPR at the arrival of the HEMS unit from 2016 to 2019 were collected from the HEMS database and patient records. We also recorded the frequency of ultrasound examinations, blood sample analyses and specific therapies provided during OHCA, such as procedures or medications other than chest compressions, airway management, ventilation, defibrillation, adrenaline or amiodarone.

RESULTS

Of the 549 patients, ultrasound was used in 331 (60%) and blood sample analyses in 136 (24%) patients during CPR. A total of 85 (15%) patients received cause-specific treatment, the most common ones being transportation to extracorporeal CPR and percutaneous coronary intervention (PCI) (n = 30), thrombolysis (n = 23), sodium bicarbonate (n = 17), calcium gluconate administration (n = 11) and fluid resuscitation (n = 10).

CONCLUSION

In our study, HEMS physicians deployed ultrasound or blood sample analyses in 84% of the encountered OHCA cases. Cause-specific treatment was administered in 15% of the cases. Our study demonstrates the frequent use of differential diagnostic tools and relatively infrequent use of cause-specific treatment during OHCA. Effect on protocol for differential diagnostics should be evaluated for more efficient cause specific treatment during OHCA.

Pulseless Electrical Activity: Detection of Underlying Causes in a Prehospital Setting

The proportion of out-of-hospital cardiac arrests (OHCAs) with pulseless electrical activity (PEA) as initial rhythm is increasing. PEA should be managed by identifying the underlying cause of the arrest and treating it accordingly. This often poses a challenge in the chaotic prehospital environment with only limited resources available. The aim of this study was to review the diagnostic tools available in a prehospital setting, and their interpretation during cardiac arrest (CA) with PEA as initial rhythm. A systematic literature search of the PubMed database was performed. Articles were assessed for eligibility by title, abstract, and full text. Ultrasonography has become a great asset in detecting underlying causes, and a variety of protocols have been proposed. There are currently no studies comparing these protocols regarding their feasibility and their effect on patient survival. Further research concerning the relationship between electrocardiogram characteristics and underlying causes is required. Limited evidence suggests a role for point-of-care testing in detecting hyperkalemia and a role for capnography in the diagnosis of asphyxia CA. Multiple studies describe a prognostic potential. Although evidence about the prognostic potential of cerebral oximetry in OHCA is accumulating, its diagnostic potential is still unknown. In the management of OHCA, anamnestic and clinical information remains the initial source of information in search for an underlying cause. Ultrasonographic evaluation should be performed subsequently, both for detecting an underlying cause and discriminating between true PEA and pseudo PEA. Comparative studies are required to identify the best ultrasonographic protocol, which can be included in resuscitation guidelines.