Novel ideas to further expand the applicability of rhythm analysis

While the laser speckle imaging (LSI) is a powerful tool for multiple biomedical applications, such as monitoring of the blood flow, in many cases it can provide additional information when combined with spatio-temporal rhythm analysis. We demonstrate the application of Graphics Processing Units (GPU)-based rhythm analysis for the post processing of LSI data, discuss the relevant structure of GPU-based computations, test the proposed technique on surrogate 3D data, and apply this approach to kidney blood flow autoregulation. Experiments with surrogate data demonstrate the ability of the method to extract information about oscillation patterns from noisy data, as well as to detect the moving source of the rhythm. The analysis of kidney data allow us to detect and to localize the dynamics arising from autoregulation processes at the level of individual nephrons (tubuloglomerular feedback (TGF) rhythm), as well as to distinguish between the TGF-active and the TGF-silent zones.

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Abstract 184: AED Application in Non-Shockable Out-of-Hospital Cardiac Arrest Does Not Reduce Survival

Circulation ◽

10.1161/circ.138.suppl_2.184 ◽

2018 ◽

Vol 138 (Suppl_2) ◽

Author(s):

Ross A Pollack ◽

Siobhan P Brown ◽

Thomas Rea ◽

Peter J Kudenchuk ◽

Myron L Weisfeldt

Keyword(s):

Cardiac Arrest ◽

Primary Outcome ◽

Patient Characteristics ◽

Neurological Status ◽

Relative Safety ◽

Initial Rhythm ◽

Bystander Cpr ◽

Rhythm Analysis ◽

In Transit ◽

Hospital Cardiac Arrest

Introduction: It is well established that AEDs improve outcome in shockable out-of-hospital cardiac arrest (OHCA). An increasing proportion (now the majority) of OHCAs present with non-shockable rhythms. Survival from non-shockable OHCA depends on high-quality CPR in transit to definitive care. Studies of AED use in non-shockable in-hospital arrest (as opposed to OHCA) have shown reduced survival with AED application possibly due to CPR interruptions to apply pads and perform rhythm analysis. We sought to determine whether AED application in non-shockable public, witnessed OHCA has a significant association with survival to discharge. Methods: This is a retrospective analysis of OHCA from 2010-2015 at 10 Resuscitation Outcomes Consortium centers. All adult, public, witnessed non-shockable OHCAs were included. Non-shockable arrest was defined as no shock delivered by the AED or by review of defibrillator tracings (10%). The initial rhythm on EMS arrival was used to confirm the rhythm. The primary outcome was survival to hospital discharge with favorable neurological status (modified rankin score <3). The OR was adjusted for the Utstein variables. Results: During the study period there were 1,597 non-shockable public, witnessed OHCA, 9.8% of which had an AED applied. The initial rhythm on EMS arrival was PEA or asystole in 86% of cases. Significantly more OHCA in the AED applied group had CPR performed. 6.5% of those without an AED applied survived with favorable neurologic status compared to 9% with an AED. After adjustment for the Utstein variables including bystander CPR, the aOR for survival with favorable neurologic outcome was 1.38 (95% CI:0.72-2.65). Conclusion: After adjusting for patient characteristics and bystander CPR, the application of an AED in non-shockable public witnessed OHCA had no significant association with survival or neurological outcome supporting the relative safety and potential benefit of AED application in non-shockable OHCA.

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Abstract P82: Implementation Of New Resuscitation Guidelines Takes One-and-a-half Year

Circulation ◽

10.1161/circ.118.suppl_18.s_1463 ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Jocelyn Berdowski ◽

Andra Schmohl ◽

Rudolph W Koster

Keyword(s):

Cardiac Arrest ◽

World Wide ◽

Prospective Observational Study ◽

Spontaneous Circulation ◽

Chest Compressions ◽

Return Of Spontaneous Circulation ◽

Resuscitation Guidelines ◽

Rhythm Analysis ◽

New Guidelines ◽

Hospital Cardiac Arrest

Objective- In November 2005, updated resuscitation guidelines were introduced world-wide, and will be revised again in 2010. This study aims to determine how long it takes to implement new guidelines. Methods- This was a prospective observational study. From July 2005 to January 2008, we included all patients with a non traumatic out-of-hospital cardiac arrest. Ambulance paramedics sent all continuous ECG registrations with impedance signal by modem. We excluded ECGs from patients with Return Of Spontaneous Circulation at arrival, incomplete ECG registrations, ECGs with technical deficits or with continuous chest compressions. The same guidelines needed to be used in over 75% of the registration time in order to be labeled. We classified ECGs as guidelines 2000 if the c:v ratio was 15:2, shock blocks were present and there was rhythm analysis after each shock; guidelines 2005 if the c:v ratio was 30:2, a single shock protocol was used and chest compressions was immediately resumed after shock or rhythm analysis in a no shock scenario. We accepted 10% deviations in the amount of compressions (13–17 for 2000 guidelines, 27–33 for 2005). Results- Of the 1703 analyzable ECGs, we classified 827 (48.6%) as guidelines 2000 and 624 (36.6%) as guidelines 2005. In the remaining 252 ECGs (14.8%) 31 used guidelines 1992, 137 applied guidelines 2000 with c:v ratio of 30:2 and 84 did not show distinguishable guideline usage. Since the introduction in November 2005, it took 17 months to apply new guidelines in over 80% of the cases (figure 1 ). Conclusion- Guideline changes are slowly implemented by professionals. This needs to be taken in consideration when new guideline revisions are considered.

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Abstract 12018: Cardiac Ultrasound Performed During Cardiac Arrest has Potential to Detect Pulmonary Embolism as a Reversible Cause of Cardiac Arrest when Compared to Hypoxia and Ventricular Fibrillation - A Randomized Porcine Study

Circulation ◽

10.1161/circ.132.suppl_3.12018 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Rasmus Aagaard ◽

Philip Caap ◽

Nicolaj C Hansson ◽

Morten T Bøtker ◽

Asger Granfeldt ◽

...

Keyword(s):

Pulmonary Embolism ◽

Cardiac Arrest ◽

Ventricular Fibrillation ◽

Life Support ◽

Advanced Life Support ◽

Ultrasound Images ◽

Cardiac Ultrasound ◽

Pilot Studies ◽

Hypoxia Group ◽

Rhythm Analysis

Introduction: Survival from non-shockable cardiac arrest is unlikely unless a reversible cause is identified and treated. Guidelines state that ultrasound has the potential to identify reversible causes. Currently, ultrasonographic findings from patients with spontaneous circulation are extrapolated to patients in cardiac arrest. While right ventricular (RV) dilation is a finding normally associated with pulmonary embolism (PE), porcine studies have shown that RV dilation is also seen in ventricular fibrillation (VF) and severe hypoxia. No studies have investigated how causes of cardiac arrest affect RV size during resuscitation. Hypothesis: The RV diameter is larger during resuscitation of cardiac arrest caused by PE when compared to hypoxia and VF. Methods: Pigs were anesthetized and randomized to cardiac arrest induced by VF, hypoxia, or PE. Advanced life support (ALS) was preceded by 7 minutes of untreated cardiac arrest. Cardiac ultrasound images of the RV from a subcostal 5-chamber view were obtained during induction of cardiac arrest and ALS. The RV diameter was measured two centimeters from the aortic valve at end diastole. RV diameter at 3rd rhythm analysis was the primary endpoint. Based on pilot studies a sample size of 8 animals in each group was needed. Results: Eight animals were included in each group. RV diameter was not statistically different at baseline (mean (95%CI)) in VF: 19.8 (18.0-21.5) mm, hypoxia: 19.8 (16.6-22.9) mm, and PE: 21.8 (19.2-24.3) mm. During induction of cardiac arrest the RV diameter increased to 29.6 (27.3-31.9) mm in the hypoxia group and 38.0 (33.4-42.6) mm in the PE group (difference to baseline and between groups, both p<0.01). Induction of VF caused an immediate increase in the RV diameter to 25.0 (21.2-28.8) mm (difference to baseline p<0.01). At 3rd rhythm analysis, RV diameter was 32.4 (28.6-36.2) mm in the PE group, which was significantly larger than both the hypoxia group at 23.3 (19.5-27.0) mm and the VF group at 24.9 (22.2-27.5) mm (difference between groups p<0.01). Conclusions: Cardiac arrest due to VF, hypoxia, and PE all caused an increase in RV diameter. During resuscitation the RV was larger in PE compared to VF and hypoxia. Cardiac ultrasound thus has the potential to detect PE during resuscitation.

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