Pneumothorax during manned chamber operations: A summary of reported cases.

In-chamber pneumothorax has complicated medically remote professional diving operations, submarine escape training, management of decompression illness, and hospital-based provision of hyperbaric oxygen therapy. Attempts to avoid thoracotomy by combination of high oxygen partial pressure breathing (the concept of inherent unsaturation) and greatly slowed rates of chamber decompression proved successful on several occasions. When this delicate balance designed to prevent the intrapleural gas volume from expanding faster than it contracts proved futile, chest drains were inserted. The presence of pneumothorax was misdiagnosed or missed altogether with disturbing frequency, resulting in wide-ranging clinical consequences. One patient succumbed before the chamber had been fully decompressed. Another was able to ambulate unaided from the chamber before being diagnosed and managed conventionally. In between these two extremes, patients experienced varying degrees of clinical compromise, from respiratory distress to cardiopulmonary arrest, with successful resuscitation. Pneumothorax associated with manned chamber operations is commonly considered to develop while the patient is under pressure and manifests during ascent. However, published reports suggest that many were pre-existing prior to chamber entry. Risk factors included pulmonary barotrauma-induced cerebral arterial gas embolism, cardiopulmonary resuscitation, and medical or surgical procedures usually involving the lung. This latter category is of heightened importance to hyperbaric operations as an iatrogenically induced pneumothorax may take as long as 24 hours to be detected, perhaps long after a patient has been cleared for chamber exposure.

The Protective Effect and Mechanism of Mild Hypothermia on Lung Injury after Cardiopulmonary Resuscitation in Pigs.

To explore the protective effect and mechanism of mild hypothermia on lung tissue damage after cardiopulmonary resuscitation in pigs. In this experiment, we electrically stimulated 16 pigs (30 ± 2 kg) for 10 min to cause ventricular fibrillation. The successfully resuscitated animals were randomly divided into two groups, a mild hypothermia group and a control group. We took arterial blood 0.5, 1, 3, and 6 h after ROSC recovery in the two groups of animals for blood gas analysis. We observed the structural changes of lung tissue under an electron microscope and calculate the wet weight/dry weight (W/D) ratio. We quantitatively analyzed the expression differences of representative inflammatory factors [interleukin-6 (IL-6) and tumor necrosis factor-alpha TNF-α)] through the ELISA test. We detected the expression levels of Bax, Bcl-2, and Caspase-3 proteins in lung tissues by Western blot. After 3 h and 6 h of spontaneous circulation was restored, compared with the control group, PaO2/FiO2 decreased significantly (P < 0.05). In addition, the pathological changes, lung W/D and lung MDA of the mild hypothermia group were better than those of the control group. The levels of IL-6 and TNF-α in the lung tissue of the mild hypothermia group were significantly lower than those of the control group (P < 0.05). The content of Caspase-3 and Bax in the mild hypothermia group was significantly lower than that of the control group. Our experiments have shown that mild hypothermia can reduce lung tissue damage after cardiopulmonary resuscitation.

Detection and Evaluation for High-Quality Cardiopulmonary Resuscitation Based on a Three-Dimensional Motion Capture System: A Feasibility Study.

High-quality cardiopulmonary resuscitation (CPR) and training are important for successful revival during out-of-hospital cardiac arrest (OHCA). However, existing training faces challenges in quantifying each aspect. This study aimed to explore the possibility of using a three-dimensional motion capture system to accurately and effectively assess CPR operations, particularly about the non-quantified arm postures, and analyze the relationship among them to guide students to improve their performance. We used a motion capture system (Mars series, Nokov, China) to collect compression data about five cycles, recording dynamic data of each marker point in three-dimensional space following time and calculating depth and arm angles. Most unstably deviated to some extent from the standard, especially for the untrained students. Five data sets for each parameter per individual all revealed statistically significant differences (p < 0.05). The correlation between Angle 1' and Angle 2' for trained (rs = 0.203, p < 0.05) and untrained students (rs = -0.581, p < 0.01) showed a difference. Their performance still needed improvement. When conducting assessments, we should focus on not only the overall performance but also each compression. This study provides a new perspective for quantifying compression parameters, and future efforts should continue to incorporate new parameters and analyze the relationship among them.

The link between initial cardiac rhythm and survival outcomes in in-hospital cardiac arrest using propensity score matching, adjustment, and weighting.

The association between the initial cardiac rhythm and short-term survival in patients with in-hospital cardiac arrest (IHCA) has not been extensively studied despite the fact that it is thought to be a prognostic factor in patients with out-of-hospital cardiac arrest. This study aimed to look at the relationship between initial shockable rhythm and survival to hospital discharge in individuals with IHCA. 1516 adults with IHCA who received chest compressions lasting at least two minutes at the National Taiwan University Hospital between 2006 and 2014 made up the study population. Propensity scores were estimated using a fitted multivariate logistic regression model. Various statistical methodologies were employed to investigate the association between shockable rhythm and the probability of survival to discharge in patients experiencing IHCA, including multivariate adjustment, propensity score adjustment, propensity score matching, and logistic regression based on propensity score weighting. In the original cohort, the multivariate-adjusted odds ratio (OR) was 2.312 (95% confidence interval [CI]: 1.515-3.531, P < 0.001). In additional propensity score adjustment, the OR between shockable rhythm and the probability of survival to hospital discharge in IHCA patients was 2.282 (95% CI: 1.486, 3.504, P < 0.001). The multivariate-adjusted logistic regression model analysis revealed that patients with shockable rhythm had a 1.761-fold higher likelihood of surviving to hospital release in the propensity score-matched cohort (OR = 2.761, 95% CI: 1.084-7.028, P = 0.033). The multivariate-adjusted OR of the inverse probability for the treatment-weighted cohort was 1.901 (95% CI: 1.507-2.397, P < 0.001), and the standardized mortality ratio-weighted cohort was 2.692 (95% CI: 1.511-4.795, P < 0.001). In patients with in-hospital cardiac arrest, Initial cardiac rhythm is an independent predictor of survival to hospital discharge. Depending on various statistical methods, patients with IHCA who have a shockable rhythm have a one to two fold higher probability of survival to discharge than those who have a non-shockable rhythm. This provides a reference for optimizing resuscitation decisions for IHCA patients and facilitating clinical communication.

Incidence, treatment, and factors associated with survival of out-of-hospital cardiac arrest attended by Spanish emergency services: report from the Out-of-Hospital Spanish Cardiac Arrest Registry for 2022. / Incidencia, tratamiento y factores asociados con la supervivencia de la parada cardiaca extrahospitalaria atendida por los servicios de emergencias en España: informe 2022 del registro OHSCAR.

SUMMARY: Out-of-hospital cardiac arrest is a serious public health problem worldwide. The annual incidence is estimated at around 400 000 cases in Europe and the United States, and survival rates scarcely reach 10%. However, there is considerable variation between countries and even between regions that share a similar health care system within a single country. Information recorded by the Out-of-Hospital Spanish Cardiac Arrest Registry (OHSCAR) provides information on care provided by emergency ambulance services, final health outcomes after cardiac arrest cases (including variations), the possibility of organ donation, and the impact of the COVID-19 pandemic. This paper presents the OHSCAR report for Spanish emergency services for the year 2022.

RESUMEN: La parada cardiorrespiratoria extrahospitalaria (PCREH) es un grave problema de salud pública mundial, con una incidencia anual estimada entorno a entorno a los 350.000 y 400.000 casos de PCERH en Europa y Estados Unidos, respectivamente. La supervivencia final se sitúa en porcentajes que apenas alcanzan el 10%, aunque existe una importante variabilidad entre países e incluso entre regiones del mismo país con modelos de atención similares. En España, el Registro Español de Parada Cardiaca Extrahospitalaria (acrónimo OHSCAR) ha ofrecido información sobre la asistencia a la PCRE prestada por los servicios de emergencias (SEM) y sus resultados finales en salud, así como sobre variabilidad, posibilidades de programas de donación o impacto de la pandemia COVID-19. A continuación se presenta el informe OHSCAR correspondiente a la asistencia a la PCRE por los SEM españoles durante el año 2022.

Impact of center volume on in-hospital mortality in adult patients with out­of­hospital cardiac arrest resuscitated using extracorporeal cardiopulmonary resuscitation: a secondary analysis of the SAVE-J II study.

Recently, patients with out-of-hospital cardiac arrest (OHCA) refractory to conventional resuscitation have started undergoing extracorporeal cardiopulmonary resuscitation (ECPR). However, the mortality rate of these patients remains high. This study aimed to clarify whether a center ECPR volume was associated with the survival rates of adult patients with OHCA resuscitated using ECPR. This was a secondary analysis of a retrospective multicenter registry study, the SAVE-J II study, involving 36 participating institutions in Japan. Centers were divided into three groups according to the tertiles of the annual average number of patients undergoing ECPR: high-volume (≥ 21 sessions per year), medium-volume (11-20 sessions per year), or low-volume (< 11 sessions per year). The primary outcome was survival rate at the time of discharge. Patient characteristics and outcomes were compared among the three groups. Moreover, a multivariable-adjusted logistic regression model was applied to study the impact of center ECPR volume. A total of 1740 patients were included in this study. The center ECPR volume was strongly associated with survival rate at the time of discharge; furthermore, survival rate was best in high-volume compared with medium- and low-volume centers (33.4%, 24.1%, and 26.8%, respectively; P = 0.001). After adjusting for patient characteristics, undergoing ECPR at high-volume centers was associated with an increased likelihood of survival compared to middle- (adjusted odds ratio 0.657; P = 0.003) and low-volume centers (adjusted odds ratio 0.983; P = 0.006). The annual number of ECPR sessions was associated with favorable survival rates and lower complication rates of the ECPR procedure.Clinical trial registration: https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000041577 (unique identifier: UMIN000036490).

Rapid Cycle Deliberate Practice Training for Simulated Cardiopulmonary Resuscitation in Resident Education.

Background: Simulation-based medical education has been used in medical training for decades. Rapid cycle deliberate practice (RCDP) is a novel simulation strategy that uses iterative practice and feedback to achieve skill mastery. To date, there has been minimal evaluation of RCDP vs standard immersive simulation (IS) for the teaching of cardiopulmonary resuscitation to graduate medical education (GME) learners. Our primary objective was to compare the time to performance of Advanced Cardiac Life Support (ACLS) actions between trainees who completed RCDP vs IS. Methods: This study was a prospective, randomized, controlled curriculum evaluation. A total of 55 postgraduate year-1 internal medicine and emergency medicine residents participated in the study. Residents were randomized to instruction by RCDP (28) or IS (27). Stress and ability were self-assessed before and after training using an anonymous survey that incorporated five-point Likert-type questions. We measured and compared times to initiate critical ACLS actions between the two groups during a subsequent IS. Results: Prior learner experience between RCDP and IS groups was similar. Times to completion of the first pulse check, chest compression initiation, backboard placement, pad placement, initial rhythm analysis, first defibrillation, epinephrine administration, and antiarrhythmic administration were similar between RCDP and IS groups. However, RCDP groups took less time to complete the pulse check between compression cycles (6.2 vs 14.2 seconds, P = 0.01). Following training, learners in the RCDP and IS groups scored their ability to lead and their levels of anticipated stress similarly (3.43 vs 3.30, (P = 0.77), 2.43 vs. 2.41, P = 0.98, respectively). However, RCDP groups rated their ability to participate in resuscitation more highly (4.50 vs 3.96, P = 0.01). The RCDP groups also reported their realized stress of participating in the event as lower than that of the IS groups (2.36 vs 2.85, P = 0.01). Conclusion: Rapid cycle deliberate practice learners demonstrated a shorter pulse check duration, reported lower stress levels associated with their experience, and rated their ability to participate in ACLS care more highly than their IS-trained peers. Our results support further investigation of RCDP in other simulation settings.

Impact of pandemic-related movement restriction on public access defibrillation in Japan: a retrospective cohort study.

OBJECTIVES: To analyse monthly changes in public access defibrillation (PAD) incidence and outcomes of out-of-hospital cardiac arrest (OHCA) during the 2020-2021 COVID-19 pandemic compared with those during the 2016-2019 prepandemic period with consideration of pandemic-related movement restriction. DESIGN: Retrospective cohort study. SETTING: An extended database was created by combining and reconciling the nationwide Utstein-style OHCA and the emergency medical service (EMS) transportation databases in Japan. PARTICIPANTS: We analysed 226 182 EMS-witnessed, non-newborn and out-of-home OHCA cases in Japan. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcomes were the PAD incidence and neurologically favourable 1-month survival rate. The secondary outcomes were bystander cardiopulmonary resuscitation (CPR) provision and dispatcher-assisted CPR attempts. RESULTS: The proportion of out-of-home OHCA cases slightly decreased during the pandemic (from 33.7% to 31.9%). Although the pandemic was associated with a decreased PAD incidence, 2-year trend analyses by an interaction test showed that the PAD incidence was lower during the first nationwide declaration of a state of emergency (p<0.001) and in the pandemic's second year (p<0.01). Regardless of location, delays in basic life support (BLS) actions and EMS contact with patients were more common and the rate of PAD-induced return of spontaneous circulation was lower during the pandemic. PAD incidence reduction was significant only in locations with a recommendation of automated external defibrillator placement (p<0.001). In other locations, a pronounced delay in BLS was found during the pandemic. The neurologically favourable survival rate was reduced in parallel with the reduced PAD incidence during the pandemic (r=0.612, p=0.002). CONCLUSIONS: Prolonged and repeated movement restrictions during the COVID-19 pandemic worsened the OHCA outcomes concurrently with disturbed BLS actions, including the reduced PAD incidence in out-of-home settings. Maintaining BLS training, re-arranging automated external defibrillator placement and establishing a local alert system for recruiting well-trained citizens to the scene are essential.

A national multi centre pre-hospital ECPR stepped wedge study; design and rationale of the ON-SCENE study.

BACKGROUND: The likelihood of return of spontaneous circulation with conventional advanced life support is known to have an exponential decline and therefore neurological outcome after 20 min in patients with a cardiac arrest is poor. Initiation of venoarterial ExtraCorporeal Membrane Oxygenation (ECMO) during resuscitation might improve outcomes if used in time and in a selected patient category. However, previous studies have failed to significantly reduce the time from cardiac arrest to ECMO flow to less than 60 min. We hypothesize that the initiation of Extracorporeal Cardiopulmonary Resuscitation (ECPR) by a Helicopter Emergency Medical Services System (HEMS) will reduce the low flow time and improve outcomes in refractory Out of Hospital Cardiac Arrest (OHCA) patients. METHODS: The ON-SCENE study will use a non-randomised stepped wedge design to implement ECPR in patients with witnessed OHCA between the ages of 18-50 years old, with an initial presentation of shockable rhythm or pulseless electrical activity with a high suspicion of pulmonary embolism, lasting more than 20, but less than 45 min. Patients will be treated by the ambulance crew and HEMS with prehospital ECPR capabilities and will be compared with treatment by ambulance crew and HEMS without prehospital ECPR capabilities. The primary outcome measure will be survival at hospital discharge. The secondary outcome measure will be good neurological outcome defined as a cerebral performance categories scale score of 1 or 2 at 6 and 12 months. DISCUSSION: The ON-SCENE study focuses on initiating ECPR at the scene of OHCA using HEMS. The current in-hospital ECPR for OHCA obstacles encompassing low survival rates in refractory arrests, extended low-flow durations during transportation, and the critical time sensitivity of initiating ECPR, which could potentially be addressed through the implementation of the HEMS system. When successful, implementing on-scene ECPR could significantly enhance survival rates and minimize neurological impairment. TRIAL REGISTRATION: Clinicaltyrials.gov under NCT04620070, registration date 3 November 2020.

Observation of the effect of hypothermia therapy combined with optimized nursing on brain protection after cardiopulmonary resuscitation: A retrospective case-control study.

This study aimed to investigate the impact of optimized emergency nursing in conjunction with mild hypothermia nursing on neurological prognosis, hemodynamics, and complications in patients with cardiac arrest. A retrospective analysis was conducted on the medical records of 124 patients who received successful cardiopulmonary resuscitation (CPR) at Fujian Provincial Hospital South Branch. The patients were divided into control and observation groups, each consisting of 62 cases. The brain function of both groups was assessed using the Glasgow Coma Scale and the National Institutes of Health Stroke Scale. Additionally, serum neuron-specific enolase level was measured in both groups. The vital signs and hemodynamics of both groups were analyzed, and the complications and satisfaction experienced by the 2 groups were compared. The experimental group exhibited significantly improved neurological function than the control group (P < .05). Furthermore, the heart rate in the experimental group was significantly lower than the control group (P < .05). However, no significant differences were observed in blood oxygen saturation, mean arterial pressure, central venous pressure, and systolic blood pressure between the 2 groups (P > 0.05). Moreover, the implementation of optimized nursing practices significantly reduced complications and improved the quality of life and satisfaction of post-CPR patients (P < .05). The integration of optimized emergency nursing practices in conjunction with CPR improves neurological outcomes in patients with cardiac arrest.

Impact of virtual problem-based learning of cardiopulmonary resuscitation on fourth-year nursing students' satisfaction and performance: a quasi-experimental study.

BACKGROUND: Regarding competency of nursing students in cardiopulmonary resuscitation (CPR), nursing students frequently exhibit inadequate performance and low satisfaction levels regarding CPR training methods. The problem-based learning (PBL) method, characterized by a constructivist approach, has been underutilized for CPR training, particularly in a virtual format. Hence, this study aims to assess the influence of virtual problem-based learning in cardiopulmonary resuscitation on the satisfaction and performance of fourth-year nursing students. METHODS: This quasi-experimental study, conducted in 2022, involved 80 final-year nursing students from Hamadan University of Medical Sciences, Iran. The participants were randomly assigned to either the experimental group (N = 40) or the control group (N = 40). The experimental group was further divided into six smaller groups on WhatsApp. Both groups initially received routine training sessions, after which the experimental group engaged in four problem-based learning sessions across three different scenarios. Data collection included demographic information, a teaching satisfaction questionnaire, and cardiopulmonary resuscitation checklists administered immediately and one month after the intervention. RESULTS: The study was initiated and concluded with 80 participants. The study commenced with no significant disparity in the mean scores of cardiopulmonary resuscitation performance, encompassing chest compressions (P = 0.451) and airway management (P = 0.378), as well as teaching satisfaction (p = 0.115) among the nursing students between the experimental and control groups. However, subsequent to the intervention, both immediately and one month later, the experimental group displayed notable enhancements in mean scores for cardiopulmonary resuscitation performance, comprising chest compressions (p < 0.001) and airway management (p < 0.001), as well as teaching satisfaction (p < 0.001) compared to the control group. CONCLUSION: Based on the study's findings, it is recommended that nursing educators implement this approach in their teaching practices.

Effect of intra-arrest transport, extracorporeal cardiopulmonary resuscitation and immediate invasive assessment in refractory out-of-hospital cardiac arrest: a long-term follow-up of the Prague OHCA trial.

BACKGROUND: Randomized data evaluating the impact of the extracorporeal cardiopulmonary resuscitation (ECPR) approach on long-term clinical outcomes in patients with refractory out-of-hospital cardiac arrest (OHCA) are lacking. The objective of this follow-up study was to assess the long-term clinical outcomes of the ECPR-based versus CCPR approach. METHODS: The Prague OHCA trial was a single-center, randomized, open-label trial. Patients with witnessed refractory OHCA of presumed cardiac origin, without return of spontaneous circulation, were randomized during ongoing resuscitation on scene to conventional CPR (CCPR) or an ECPR-based approach (intra-arrest transport, ECPR if ROSC is not achieved prehospital and immediate invasive assessment). RESULTS: From March 2013 to October 2020, 264 patients were randomized during ongoing resuscitation on scene, and 256 patients were enrolled. Long-term follow-up was performed 5.3 (interquartile range 3.8-7.2) years after initial randomization and was completed in 255 of 256 patients (99.6%). In total, 34/123 (27.6%) patients in the ECPR-based group and 26/132 (19.7%) in the CCPR group were alive (log-rank P = 0.01). There were no significant differences between the treatment groups in the neurological outcome, survival after hospital discharge, risk of hospitalization, major cardiovascular events and quality of life. Of long-term survivors, 1/34 (2.9%) in the ECPR-based arm and 1/26 (3.8%) in the CCPR arm had poor neurological outcome (both patients had a cerebral performance category score of 3). CONCLUSIONS: Among patients with refractory OHCA, the ECPR-based approach significantly improved long-term survival. There were no differences in the neurological outcome, major cardiovascular events and quality of life between the groups, but the trial was possibly underpowered to detect a clinically relevant difference in these outcomes. Trial registration ClinicalTrials.gov Identifier: NCT01511666, Registered 19 January 2012.

The Pharmacologic Management of Cardiac Arrest.

The effectiveness of pharmacologic management of cardiac arrest patients is widely debated; however, several studies published in the past 5 years have begun to clarify some of these issues. This article covers the current state of evidence for the effectiveness of the vasopressor epinephrine and the combination of vasopressin-steroids-epinephrine and antiarrhythmic medications amiodarone and lidocaine and reviews the role of other medications such as calcium, sodium bicarbonate, magnesium, and atropine in cardiac arrest care. We additionally review the role of ß-blockers for refractory pulseless ventricular tachycardia/ventricular fibrillation and thrombolytics in undifferentiated cardiac arrest and suspected fatal pulmonary embolism.

Out-of-Hospital Cardiac Arrest.

Survival from out-of-hospital cardiac arrest (OHCA) is predicated on a community and system-wide approach that includes rapid recognition of cardiac arrest, capable bystander CPR, effective basic and advanced life support (BLS and ALS) by EMS providers, and coordinated postresuscitation care. Management of these critically ill patients continues to evolve. This article focuses on the management of OHCA by EMS providers.

Cardiac Arrest in Special Populations.

Best practices in cardiac arrest depend on continuous high-quality chest compressions, appropriate ventilatory management, early defibrillation of shockable rhythms, and identification and treatment of reversible causes. Although most patients can be treated according to highly vetted treatment guidelines, some special situations in cardiac arrest arise where additional skills and preparation can improve outcomes. Situations covered in this section involve cardiac arrest in context of electrical injuries, asthma, allergic reactions, pregnancy, trauma, electrolyte imbalances, toxic exposures, hypothermia, drowning, pulmonary embolism, and left ventricular assist devices.