Cardiac arrest related lung edema: examining the role of downtimes in transpulmonary thermodilution analysis.

Pulmonary edema and its association with low flow times has been observed in postcardiac arrest patients. However, diagnosis of distinct types of lung pathology is difficult.The aim of this study was to investigate pulmonary edema by transpulmonary thermodilution (TPTD) after out-of-hospital cardiac arrest (OHCA), and the correlation to downtimes. In this retrospective single-center study consecutive patients with return of spontaneous circulation (ROSC) following OHCA, age ≥ 18, and applied TPTD were enrolled. According to downtimes, patients were divided into a short and a long no-flow-time group, and data of TPTD were analysed. We identified 45 patients (n = 25 short no-flow time; n = 20 long no-flow time) who met the inclusion criteria. 24 h after ROSC, the extra vascular lung water index (EVLWI) was found to be lower in the group with short no-flow time compared to the group with long no-flow time (10.7 ± 3.5 ml/kg vs. 12.8 ± 3.9 ml/kg; p = 0.08) and remained at a similar level 48 h (10.9 ± 4.3 ml/kg vs. 12.9 ± 4.9 ml/kg; p = 0.25) and 72 h (11.1 ± 5.0 ml/kg vs. 13.9 ± 7.7 ml/kg; p = 0.27) post-ROSC. We found a statistically significant and moderate correlation between no-flow duration and EVLWI 48 h (r = 0.51; p = 0.002) and 72 h (r = 0.54; p = 0.004) post-ROSC. Pulmonary vascular permeability index (PVPI) was not correlated with downtimes. Our observation underlines the presence of cardiac arrest-related lung edema by determination of EVLWI. The duration of no-flow times is a relevant factor for increased extravascular lung water index.

An effort to reduce chest compression pauses during automated external defibrillator use among laypeople: A randomized partially blinded controlled trial.

Aim: To implement small methodological changes in basic life support (BLS) training to reduce unnecessary pauses during automated external defibrillator (AED) use. Methods: One hundred and two university students with no BLS knowledge were randomly allocated into three groups (control and 2 experimental groups). Both experimental groups received a two-hour BLS training. While the contents were identical in both groups, in one of them the reduction of no-flow time was focused on (focused no-flow group). The control group did not receive any training. Finally, all of them were evaluated in the same out-of-hospital cardiac arrest simulated scenario. The primary endpoint was the compression fraction. Results: Results from 78 participants were analysed (control group: 19; traditional group: 30; focused no-flow group: 29). The focused no-flow group achieved higher percentages of compression fraction (median: 56.0, interquartile rank (IQR): 53.5-58.5) than the traditional group (44.0, IQR: 42.0-47.0) and control group (52.0, IQR: 43.0-58.0) in the complete scenario. Participants from the control group performed compression-only cardiopulmonary resuscitation (CPR), while the other groups performed compression-ventilation CPR. CPR fraction was calculated, showing the fraction of time in which the participants were performing resuscitation manoeuvres. In this case, the focused no-flow group reached higher percentages of CPR fraction (77.6, IQR: 74.4-82.4) than the traditional group (61.9, IQR: 59.3-68.1) and the control group (52.0, IQR: 43.0-58.0). Conclusions: Laypeople having automated external defibrillation training focused on acting in anticipation of the AED prompts contributed to a reduction in chest compression pauses during an OHCA simulated scenario.

The association between CPR quality of In-hospital resuscitation and sex: A hypothesis generating, prospective observational study.

Introduction: The relationship between sex and cardiopulmonary resuscitation (CPR) outcomes remains unclear. Particularly, questions remain regarding the potential contribution of unmeasured confounders. We aimed to examine the differences in the quality of chest compression delivered to men and women. Methods: Prospective study of observational data recorded during consecutive resuscitations occurring in a single tertiary center (Feb-1-2015 to Dec-31-2018) with real-time follow-up to hospital discharge. The studied variables included time in CPR, no-flow-time and fraction, compression rate and depth and release velocity. The primary study endpoint was the unadjusted association between patient sex and the chest compression quality (depth and rate). The secondary endpoint was the association between the various components of chest compression quality, sex, and survival to hospital discharge/neurologically intact survival. Results: Overall 260 in-hospital resuscitations (57.7% male patients) were included. Among these 100 (38.5%) achieved return of spontaneous circulation (ROSC) and 35 (13.5%) survived to hospital discharge. Female patients were significantly older. Ischemic heart disease and ventricular arrhythmias were more prevalent among males. Compression depth was greater in female vs male patients (54.9 ± 11.3 vs 51.7 ± 10.9 mm; p = 0.024). Other CPR quality-metrics were similar. The rates of ROSC, survival to hospital discharge and neurologically intact survival did not differ between males and females. Univariate analysis revealed no association between sex, quality metrics and outcomes. Discussion: Women received deeper chest compressions during in-hospital CPR. Our findings require corroboration in larger cohorts but nonetheless underscore the need to maintain high-quality CPR in all patients using real-time feedback devices. Future studies should also include data on ventilation rates and volumes which may contribute to survival outcomes.

Electrical rhythm degeneration in adults with out-of-hospital cardiac arrest according to the no-flow and bystander low-flow time.

AIMS: For out-of-hospital cardiac arrest (OHCA) patients, the influence of the delay before the initiation of resuscitation, termed the no-flow time (NFT), and duration of bystander-only resuscitation low-flow time (BLFT) on the type of electrical rhythm observed has not been well described. The objective of this study is to determine the relationship between NFT, BLFT and the likelihood of a shockable rhythm over time. METHODS: Using a North American prospective registry (2005-2015; mostly urban settings), we selected adult (18 years and over) patients who experienced a witnessed OHCA from a suspected cardiac etiology. Patients with an emergency medical services witnessed OHCA were only included in sensitivity analyses. The association between the NFT, BLFT and the presence of a shockable rhythm was evaluated using a multivariable logistic regression adjusting for the registry version, age, sex, and public location. RESULTS: A total of 229,632 patients were logged in the registry, 50,957 of whom were included. Of these, 17,704 (34.7%) had an initial shockable rhythm. After the first minute, a significant decrease over time in the occurrence of shockable rhythm is observed but is slower when bystander cardiopulmonary resuscitation (CPR) is provided (each supplemental minute of BLFT: adjusted odds ratio = 0.95, 95 %CI = 0.94-0.95; each supplemental minute of NFT: adjusted odds ratio = 0.91, 95 %CI = 0.90-0.91]). CONCLUSIONS: In this large observational study, we were able to demonstrate that longer NFT were associated with lower odds of shockable presenting rhythms. Bystander CPR significantly mitigates the degradation of shockable rhythms over time, strengthening the need to improve bystander CPR rates around the world.

Extracorporeal cardiopulmonary resuscitation without target temperature management for out-of-hospital cardiac arrest patients prolongs the therapeutic time window: a retrospective analysis of a nationwide multicentre observational study in Japan.

BACKGROUND: Extracorporeal cardiopulmonary resuscitation (ECPR) with extracorporeal membrane oxygenation (ECMO) is a promising therapy for out-of-hospital cardiac arrest (OHCA) compared with conventional cardiopulmonary resuscitation (CCPR). The no and low-flow time (NLT), the interval from collapse to reperfusion to starting ECMO or to the return of spontaneous circulation (ROSC) in CCPR, is associated with the neurological outcome of OHCA. Because the effects of target temperature management (TTM) on the outcomes of ECPR are unclear, we compared the neurological outcomes of OHCA between ECPR and CCPR without TTM. METHODS: We performed retrospective subanalyses of the Japanese Association for Acute Medicine OHCA registry. Witnessed cases of adult cardiogenic OHCA without TTM were selected. We performed univariate, multivariable and propensity score analyses to compare the neurological outcomes after ECPR or CCPR in all eligible patients and in patients with NLT of > 30 min or > 45 min. RESULTS: We analysed 2585 cases. Propensity score analysis showed negative result in all patients (odds ratio 0.328 [95% confidence interval 0.141-0.761], P = 0.010). However, significant associated with better neurological outcome was shown in patients with NLT of > 30 min or > 45 min (odds ratio 2.977 [95% confidence interval 1.056-8.388], P = 0.039, odds ratio 5.099 [95% confidence interval 1.259-20.657], P = 0.023, respectively). CONCLUSION: This study revealed significant differences in the neurological outcomes between ECPR and CCPR without TTM, in patients with NLT of > 30 min.

Association of ultrasound-related interruption during cardiopulmonary resuscitation with adult cardiac arrest outcomes: A video-reviewed retrospective study.

OBJECTIVES: To determine the association of focused transthoracic echocardiography (ECHO) related interruption during cardiopulmonary resuscitation (CPR) with patient outcomes in the Emergency Department (ED). METHODS: This was a retrospective, single center, cohort study, conducted in an urban community teaching ED. Eligible study subjects were adult patients in the ED with sustained cardiac arrest. Exclusion criteria include traumatic cardiac arrest and age less than 18. All resuscitations were video recorded and were subsequently reviewed by 2 study investigators. The no-flow time from chest compression interruption was analyzed using video review and separated into ECHO-related and non-ECHO related. Our primary outcome was patient survival to hospital discharge and the secondary outcome was the rate of return of spontaneous circulation (ROSC). Multivariate logistic regression analyses were performed to examine the associations between independent variables and outcomes. RESULTS: From January 2016 to May 2017, a total of 210 patients were included for final analysis. The median total no-flow time observed on video was 99.5 s (IQR: 54.0-160.0 s). Among these, a median of 26.5 s (IQR: 0.0-59.0 s) was ECHO-related and a median of 60.5 s (IQR: 34.0-101.9) was non-ECHO-related. The ECHO-related no-flow time between 77 and 122 s (OR: 7.31, 95 % confidence interval [CI]: 1.59-33.59; p-value = 0.01) and ECHO-related interruption ≦ 2 times (OR: 8.22, 95% CI: 1.51-44.64; p-value = 0.01) were positively associated with survival to hospital discharge. ECHO-related interruption ≦ 2 times (OR: 5.55, 95% CI: 2.44-12.61; p-value < 0.001) was also positively associated with ROSC. CONCLUSION: Short ECHO-related interruption during CPR was positively associated with ROSC and survival to hospital discharge. While ECHO can be a valuable diagnostic tool during CPR, the no-flow time associated with ECHO should be minimized.

Defibrillator charging before rhythm analysis causes peri-shock pauses exceeding guideline recommended maximum 5 s : A randomized simulation trial.

INTRODUCTION: Charging defibrillators prior to analyzing heart rhythms may decrease the no-flow time during rhythm check pauses while resuscitating in cardiac arrest. Although this anticipatory method is already used in some centers little is known about its safety. This study was carried out to confirm the safety and feasibility of the anticipatory method. It was hypothesized that this anticipatory method results in shorter total no-flow times, while other parameters of defibrillation efficacy including defibrillator safety and minimization of peri-shock pauses are unchanged. METHODS: This manikin study assigned 243 medical students randomly to study groups, 121 to the anticipatory method and 122 to the recommended European Resuscitation Council (ERC) algorithm. Of these 237 students ultimately underwent training (112 anticipatory method vs. 125 ERC algorithm). Participants were assessed and video recorded during a simulated cardiac arrest scenario which included three different heart rhythms (ventricular fibrillation [VF], pulseless ventricular tachycardia [pVT], asystole) in randomized order. Video and software analyses were performed. Defibrillation safety was assessed using a 17-item checklist defined beforehand. RESULTS: A total of 203 simulated cardiac arrests (75 anticipatory method and 128 ERC 2010 algorithm) were analyzed. The anticipatory method did not significantly reduce no-flow time (25.8 s, standard deviation, SD 7.4 s vs. 27.4 s SD 8.4 s, p = 0.19); however, peri-shock pauses were significantly longer in the anticipatory group compared to the ERC 2010 group (9.5 s SD 2.8 s vs. 3.3 s SD 1.9 s, p < 0.001). No significant difference concerning defibrillation safety between the groups was observed according to the 17-item checklist (14.6 SD 1.6 vs. 15.0 SD 1.4, p = 0.07). CONCLUSION: Charging defibrillators before rhythm analysis did not decrease total no-flow time in simulated cardiac arrests but resulted in significantly longer peri-shock pauses exceeding 5 s. No significant differences in defibrillation safety were observed between the groups.

Effect of using a laryngeal tube on the no-flow time in a simulated, single-rescuer, basic life support setting with inexperienced users.

BACKGROUND: The laryngeal tube (LT) is a recommended alternative to endotracheal intubation during advanced life support (ALS). Its insertion is relatively simple; therefore, it may also serve as an alternative to bag mask ventilation (BMV) for untrained personnel performing basic life support (BLS). Data support the influence of LT on the no-flow time (NFT) compared with BMV during ALS in manikin studies. METHODS: We performed a manikin study to investigate the effect of using the LT for ventilation instead of BMV on the NFT during BLS in a prospective, randomized, single-rescuer study. All 209 participants were trained in BMV, but were inexperienced in using LT; each participant performed BLS during a 4-min time period. RESULTS: No significant difference in total NFT (LT: mean 81.1 ± 22.7 s; BMV: mean 83.2 ± 13.1 s, p = 0.414) was found; however, significant differences in the later periods of the scenario were identified. While ventilating with the LT, the proportion of chest compressions increased significantly from 67.2 to 73.2%, whereas the proportion of chest compressions increased only marginally when performing BMV. The quality of the chest compressions and the associated ventilation rate did not differ significantly. The mean tidal volume and mean minute volume were significantly lower when performing BMV. CONCLUSIONS: The NFT was significantly shorter in the later periods in a single-rescuer, cardiac arrest scenario when using an LT without previous training compared with BMV with previous training. A possible explanation for this result may be the complexity and workload of alternating tasks (e.g., time loss when reclining the head and positioning the mask for each ventilation during BMV).

Effect of the laryngeal tube on the no-flow-time in a simulated two rescuer basic life support setting with inexperienced users.

INTRODUCTION: Intubation with a laryngeal tube (LT) is a recommended alternative to endotracheal intubation during advanced life support (ALS). LT insertion is easy; therefore, it may also be an alternative to bag-mask ventilation (BMV) for untrained personnel performing basic life support (BLS). Data from manikin studies support the influence of LT on no-flow-time (NFT) during ALS. METHODS: We performed a prospective, randomized manikin study using a two-rescuer model to compare the effects of ventilation using a LT and BMV on NFT during BLS. Participants were trained in BMV and were inexperienced in the use of a LT. RESULTS: There was no significant difference in total NFT with the use of a LT and BMV (LT: mean 83.1 ± 37.3 s; BMV: mean 78.7 ± 24.5 s; p = 0.313), but we found significant differences in the progression of the scenario: in the BLS-scenario, the proportion of time spent performing chest compressions was higher when BMV was used compared to when a LT was used. The quality of chest compressions and the ventilation rate did not differ significantly between the two groups. The mean tidal volume and mean minute volume were significantly larger with the use of a LT compared with the use of BMV. CONCLUSIONS: In conclusion, in a two-rescuer BLS scenario, NFT is longer with the use of a LT (without prior training) than with the use of BMV (with prior training). The probable reasons for this result are higher tidal volumes with the use of a LT leading to longer interruptions without chest compressions.

Obstacles delaying the prompt deployment of piston-type mechanical cardiopulmonary resuscitation devices during emergency department resuscitation: a video-recording and time-motion study.

BACKGROUND: The quality of cardiopulmonary resuscitation (CPR) is important to survival after cardiac arrest. Mechanical devices (MD) provide constant CPR, but their effectiveness may be affected by deployment timeliness. OBJECTIVES: To identify the timeliness of the overall and of each essential step in the deployment of a piston-type MD during emergency department (ED) resuscitation, and to identify factors associated with delayed MD deployment by video recordings. METHODS: Between December 2005 and December 2008, video clips from resuscitations with CPR sessions using a MD in the ED were reviewed using time-motion analyses. The overall deployment timeliness and the time spent on each essential step of deployment were measured. RESULTS: There were 37 CPR recordings that used a MD. Deployment of MD took an average 122.6 ± 57.8s. The 3 most time-consuming steps were: (1) setting the device (57.8 ± 38.3s), (2) positioning the patient (33.4 ± 38.0 s), and (3) positioning the device (14.7 ± 9.5s). Total no flow time was 89.1 ± 41.2s (72.7% of total time) and associated with the 3 most time-consuming steps. There was no difference in the total timeliness, no-flow time, and no-flow ratio between different rescuer numbers, time of day of the resuscitation, or body size of patients. CONCLUSIONS: Rescuers spent a significant amount of time on MD deployment, leading to long no-flow times. Lack of familiarity with the device and positioning strategy were associated with poor performance. Additional training in device deployment strategies are required to improve the benefits of mechanical CPR.