Pulmonary fat embolism in non-survivors after cardiopulmonary resuscitation.

BACKGROUND: Blunt trauma acting against the human body presents the fundamental cause of pulmonary fat embolism (PFE) and fat embolism syndrome. The aim of the present study was to investigate PFE in non-survivors after cardiopulmonary resuscitation (CPR). METHODS: This was a prospective cohort study conducted in University Hospital Ostrava, Czech Republic. Within a 4-year study period, all non-survivors after CPR because of out-of-hospital cardiac arrest were assessed for the study eligibility. The presence/seriousness of PFE was determined by microscopic examination of cryo-sections of lung tissue (staining with Oil Red O). RESULTS: In total, 106 persons after unsuccessful CPR were enrolled in the study. The most frequent cause of death in the study population (63.2% of cases) was cardiac disease (ischemic heart disease); PFE was not determined as the cause of death in any of our study cases. Sternal fractures were identified 66.9%, rib fractures (usually multiple) in 80.2% of study cases; the median number of rib fractures was 10.2 fractures per person. Serious intra-thoracic injuries were found in 34.9% of cases. Microscopic examination of lung cryo-sections revealed PFE in 40 (37.7%) study cases; PFE was most frequently evaluated as grade I or II. Occurrence of sternal and rib fractures was significantly higher in persons with PFE than between persons without PFE (p = 0.033 and p = <0.001). Number of rib fractures was also significantly higher in persons with PFE. The occurrence of serious intra-thoracic injuries was comparable in both our study groups (p = 0.089). CONCLUSIONS: PFE presents a common resuscitation injury which can be found in more than 30% of persons after CPR. Persons with resuscitation skeletal chest fractures have significantly higher risk of PFE development. During autopsy of persons after unsuccessful CPR, it is necessary to distinguish CPR-associated injuries including PFE from injuries that arise from other mechanisms.

Can support surfaces characteristics influence high-quality chest compression? manikin experiment with a mechanical device.

BACKGROUND: Support surfaces variables, such as size, material, and density, can determine chest compression depth in cardiopulmonary resuscitation. OBJECTIVE: to analyze the force required to do a high-quality chest compression concerning different surfaces in CPR. METHOD: This experimental study was developed using a Little Anne manikin and a mechanical device to perform chest compressions. Nine sets of surfaces were tested and compared to a control. RESULTS: 230 experimental tests were done in sets of bed or stretcher + mattress and presence or absence of different backboards. In the control condition, the average force to reach 5 cm of depth was 42.14±0.97 (kgf). Set 9, compatible with a narrow stretcher with a thin mattress, had the best surfaces to reach recommended depth, with or without a backboard. All other sets required significantly more force for high-quality chest compression. Regression analysis confirms that backboard size is not significant for the force for high-quality chest compression. CONCLUSION: There is an association of dimensions and types of beds or stretchers and mattresses with a force increase. Type and dimensions of the backboard are not relevant for the force required, regardless of the characteristics of the set of the bed or stretcher and mattress.

Characterization of cerebral blood flow during open cardiac massage in swine: Effect of volume status.

Introduction: Patients in cardiac arrest treated with resuscitative thoracotomy and open cardiac massage (OCM) have high rates of mortality with poor neurological outcomes. The aim of this study is to quantitate cerebral perfusion during OCM using computed tomography perfusion (CTP) imaging in a swine model of normo- and hypovolemia. Methods: Anesthetized swine underwent instrumentation with right atrial and aortic pressure catheters. A catheter placed in the ascending aorta was used to administer iodinated contrast and CTP imaging acquired. Cerebral blood flow (CBF; ml/100 g of brain) and time to peak (TTP; s) were measured. Animals were then euthanized by exsanguination (hypovolemic group) or potassium chloride injection (normovolemic group) and subjected to a clamshell thoracotomy, aortic cross clamping, OCM, and repeated CTP. Data pertaining to peak coronary perfusion pressure (pCoPP; mmHg) were collected and % CoPP > 15 mmHg (% CoPP; s) calculated post hoc. Results: Normovolemic animals (n = 5) achieved superior pCoPP compared to the hypovolemic animals (n = 5) pCoPP (39.3 vs. 12.3, p < 0.001) and % CoPP (14.5 ± 1.9 vs. 30.9 ± 6.5, p < 0.001). CTP acquisition was successful and TTP elongated from spontaneous circulation, normovolemia to hypovolemia (5.7 vs. 10.8 vs. 14.8, p = 0.01). CBF during OCM was similar between hypovolemic and normovolemic groups (7.5 ± 8.1 vs. 4.9 ± 6.0, p = 0.73) which was significantly lower than baseline values (51.9 ± 12.1, p < 0.001). Conclusion: OCM in normovolemia generates superior coronary hemodynamics compared to hypovolemia. Despite this, neither generates adequate CBF as measured by CTP, compared to baseline. To improve the rate of neurologically intact survivors, novel resuscitative techniques need to be investigated that specifically target cerebral perfusion as existing techniques are inadequate.

Prevalence, Outcomes, and Risk Factors for Cardiorespiratory Arrest in the Intensive Care Unit: An Observational Study.

Background: Cardiorespiratory arrest is defined as an abrupt halt in the cardiac mechanical activity that is accompanied by the loss of a detectable pulse, the cessation of breathing, and the loss of consciousness. The aim of this study is to create a clinical-epidemiological profile of patients who experienced cardiorespiratory arrest and were admitted to the intensive care unit to evaluate the associated factors and their impact on the prognosis of these patients. Patients and methods: From January to December 2019, the medical records of 135 patients who received cardiopulmonary resuscitation were reviewed for this cross-sectional observational study. The information was collected according to the Utstein model. Results: A low return of spontaneous circulation of 22.2% was observed, with a predominance of females (53.3%) and older patients (68.9%), multiple comorbidities at admission (68.4%), and asystole as the predominant rhythm. Female sex and age >60 years were statistically significant (p = 0.017), as was the association between sex and comorbidities (p = 0.036), with heart disease being the most prevalent in females (p = 0.036). Conclusion: In this study, even though the resuscitation maneuver time (start of resuscitation following arrest) was very short and the defibrillation was performed promptly, there was a high prevalence of cardiac arrest and low survival rates after cardiopulmonary resuscitation. How to cite this article: Menezes da Silva A, Braga AL, Cruvinel de Souza V. Prevalence, Outcomes, and Risk Factors for Cardiorespiratory Arrest in the Intensive Care Unit: An Observational Study. Indian J Crit Care Med 2022;26(6):704-709.

Magnitude of mitral valve closure plays a pivotal role in enhancing the forward blood flow during cardiac massage in dogs with ventricular fibrillation.

Motion of mitral valve during cardiac massage was examined using beagle dogs with ventricular fibrillation (n=4). Active compression-decompression cardiac massage (ACD-CM) exhibited greater peak aortic pressure than standard cardiac massage (S-CM), reverse of which was true for peak pulmonary capillary wedge pressure in each animal. Accordingly, peak aortic pressure was greater than peak pulmonary capillary wedge pressure with ACD-CM, whereas its reverse was true with S-CM. Transesophageal echocardiography revealed that mitral valve was incompletely closed with S-CM with showing regurgitation. The valve was more effectively closed during ACD-CM. These results indicate that effective closure of mitral valve during cardiac massage may increase forward blood flow, supporting "cardiac pump theory" rather than "thoracic pump theory" as a principle in dogs.

Open chest selective aortic arch perfusion vs open cardiac massage as a means of perfusion during in exsanguination cardiac arrest: a comparison of coronary hemodynamics in swine.

AIM: To describe and compare the aortic-right atrial pressure (AoP-RAP) gradients and mean coronary perfusion pressures (CPPs) generated during open chest selective aortic arch perfusion (OCSAAP) with those generated during open cardiac massage (OCM) in hypovolemic swine. METHODS: Ten male Hanford swine utilized in a prior poly-trauma study were included in the study. Animals were rendered hypovolemic via a 30% volume bleed. Upon confirmation of death, animals underwent immediate clamshell thoracotomy and aortic cross-clamping followed by 5 min of OCM. A catheter suitable for OCSAAP was then inserted into the aorta and animals underwent 1 min of OCSAAP at a rate of 10 mL/kg/min. Aortic and right atrial pressures were recorded continuously using solid-state blood pressure catheters. Representative 10-s intervals from each resuscitation method were extracted. Hemodynamic parameters including AoP-RAP gradients and CPPs were calculated and compared. RESULTS: At baseline, time from death to intervention was significantly shorter for OCM. However, mean CPPs and AoP-RAP gradients were significantly higher in animals undergoing OCSAAP. 98% of OCSAAP segments had a mean CPP > 15, compared to 35% of OCM intervals. While OCM had a significant negative correlation between time to intervention and maximum CPP, this correlation was not significant for OCSAAP. CONCLUSION: OCSAAP generates favorable and potentially time-resistant pressure gradients when compared to those generated by OCM. Further investigation of the technique of OCSAAP is warranted, as it may have potential utility as a therapy during resuscitative thoracotomy (RT).

Efficacy of a Simplified Feedback Trainer for High-Quality Chest Compression Training: A Randomized Controlled Simulation Study.

Background: The most recent international guidelines recommended support training of chest compression (CC) using feedback devices. This study aimed to compare the training efficacy of a simplified feedback trainer with the traditional cardiopulmonary resuscitation (CPR) simulator in CPR training. Methods: A total of 60 soldiers were randomly allocated into three groups equally, trained with a simplified external cardiac massage (ECM) trainer named Soul SheathTM (SS) (SS group), a Resusci Anne manikin (RA group), or traditional simulation training with instructor feedback, respectively. After 7 days of training, the CPR skills were tested blindly in a 2-min assessment session. The primary outcome was the proportion of effective CC, and the secondary outcome included CC rate, depth, compression position, and extent of the release. Results: The percentage of effective CC achieved in the SS group was comparable with the RA group (77.0 ± 15.52 vs. 77.5 ± 10.73%, p = 0.922), and significantly higher than that in the control group (77.0 ± 15.52 vs. 66.8 ± 16.87%, p = 0.037). Both the SS and RA groups showed better CC performance than the control group in terms of CC rate (SS group vs. control group, P = 0.032 and RA group vs. control group, P = 0.026), the proportion of shallow CC (SS group vs. control group, P = 0.011 and RA group vs. control group, P = 0.017). No difference between the SS group and RA group was found in all the CC parameters. Conclusions: The simplified ECM trainer (SS) provides a similar efficacy to the traditional manikin simulator with feedback in CC training to improve the quality of CPR skills.

Different perceptions of thorax anatomy and hand placement for chest compressions among healthcare professionals and laypersons: Implications for cardiopulmonary resuscitation.

AIM: The European Resuscitation Council guidelines recommend that the hand position for chest compressions is obtained by "placing the heel of your hand in the centre of the chest". Importantly, guidelines are based on a study on healthcare professionals being extrapolated to laypersons. This study explored whether healthcare professionals and laypersons differ in anatomical knowledge necessary for obtaining the correct hand position for chest compressions and understanding of European Resuscitation Council guideline recommendations in the absence of a demonstration. METHODS: We asked laypersons and healthcare professionals to identify where to place the hands for chest compressions on digital pictures of the chest of a man and a woman. Both groups were asked to identify where to place the hands for chest compressions, the left nipple (positive control), the centre of the chest and to delineate the anterior area of the chest. RESULTS: In total, 50 laypersons and 50 healthcare professionals were included. Healthcare professionals were significantly better at identifying the correct hand position for chest compressions compared to laypersons (male chest: P = 0.03, female chest: P < 0.0001) and delineating the anterior area of the chest. We found no significant difference between groups when instructed to identify the left nipple nor the centre of the chest (male chest: P = 0.57, female chest: P = 0.50). CONCLUSION: Laypersons and healthcare professionals have different perceptions of chest anatomy and where to perform chest compressions suggesting that caution should be taken when extrapolating results from healthcare professionals to laypersons. The ERC 2015 guideline recommendations on hand placement for chest compressions seems understandable by both laypersons and healthcare professionals.

Two autopsy cases with injuries to the stomach following cardiopulmonary resuscitation.

We herein report two autopsy cases with gastric injury associated with cardiopulmonary resuscitation (CPR). Case 1 was a 36-year-old woman who was found in cardiopulmonary arrest possibly caused by a fall from a height of 8 m. She received continuous manual chest compression with artificial ventilation while being transferred to the hospital. Autopsy revealed bruises on her left upper arm with a fracture to the left humerus and advanced pneumohemothorax that was associated with laceration of the left lung due to fracture of the dorsal left costa. Furthermore, complete rupture of the gastric wall (25 cm) was found without hemorrhage. Case 2 was an 85-year-old man found unconscious on the road. He had a history of oral anticoagulant administration, cognitive impairment, and gait disorder. He also received cardiac massage and manual artificial ventilation during CPR. Autopsy revealed severe head injury, possibly caused by a backward fall. His stomach was markedly dilated by air and a fresh intramural hematoma had extended into all layers of the stomach and adjacent omentum; however, injury of the abdominal wall was not evident. Histopathological investigation of the brain revealed advanced Alzheimer's disease and Lewy pathology, and the damaged neural tissue, which was positive for the amyloid precursor protein. We determined that the gastric injuries in both cases had been caused by CPR. We conclude that careful investigation is required for gastric injury cases to determine the etiology and correlation between gastric injury and cause of death when the victims receive CPR.

Selective aortic arch perfusion versus open cardiac massage in exsanguination cardiac arrest: A comparison of coronary pressure dynamics in swine.

AIM: To evaluate the mean aortic-right atrial pressure (AoP-RAP) gradients and mean coronary perfusion pressures (CPPs) observed during open cardiac massage (OCM) versus those obtained with selective aortic arch perfusion (SAAP) in post-mortem hypovolemic swine. METHODS: Post-mortum, male swine, utilized in prior studies of hemorrhage, were included in the study. Animals were bled ∼25-50% of circulating volume prior to death. Animals either underwent clamshell thoracotomy and OCM immediately after death was confirmed (n = 6) or underwent SAAP within 5-15 min of death (n = 6). Aortic root and right atrial pressures were recorded continuously during each method of resuscitation using solid state blood pressure catheters. Representative five beat samples were extracted; short, similarly timed segments of SAAP were also extracted. Mean AoP-RAP gradient and CPPs were calculated and compared. RESULTS: Mean AoP-RAP gradient and CPP were significantly higher in SAAP animals compared to OCM animals (mean ±â€¯SD; 29.1 ±â€¯8.4 vs. 24.5 ±â€¯5.0, p < 0.001; 28.9 ±â€¯8.5 vs. 9.9 ±â€¯6.0, p < 0.001). Mean CPP was not significantly different from mean AoP-RAP gradient in SAAP animals (p = 0.92); mean CPP was significantly lower than mean AoP-RAP gradient in OCM animals (p < 0.001). While 97% of SAAP segments had a CPP > 15 mmHg, only 17% of OCM segments had a CPP > 15 mmHg (p < 0.001). CONCLUSION: SAAP appears to create a more favorable and efficient hemodynamic profile for obtaining ROSC when compared to OCM in this preclinical porcine study.

Transesophageal echocardiography in patients with cardiac arrest: from high-quality chest compression to effective resuscitation.

BACKGROUND: Survival after cardiac arrest depends on prompt and effective cardiopulmonary resuscitation (CPR). Transesophageal echocardiography (TEE) can be applied to evaluate the effectiveness of chest compression-decompression maneuvers in the setting of cardiac arrest undergoing CPR. The efficacy of chest compression can be continuously assessed by TEE that can improve the effectiveness of CPR guiding the rescuer to optimize or correct chest compression and decompression by directly examining the movements of the cardiac walls and valve leaflets. PURPOSE: The review describes how to perform TEE in the emergency setting of cardiopulmonary arrest, its advantages, and limitations, and ultimately propose an echo-guided approach to CPR.

Possibilities of using open chest cardiac massage in sudden, non-traumatic cardiac arrest.

Cardiopulmonary resuscitation is one of the most studied procedures in medicine. Over the years, despite numerous scientific studies, changes in guidelines, refining algorithms, expanding the availability of resuscitation equipment and educating the public, it has not been possible to improve the results of treatment of patients after cardiac arrest. Only 10% of them survive until hospital discharge. There is a well-tested medical procedure, wide application of which could improve results of resuscitation. This procedure is open chest cardiac massage (OCCM). OCCM is not a new technique, its use dates back to the nineteenth century, now it is reserved for patients sustaining trauma and those after surgical procedures. A number of experimental and clinical studies have proven its advantage over the currently preferred indirect massage (CCCM) also in the group of non- traumatic patients. Of course, OCCM is an invasive method with a number of possible complications accompanying surgical procedures, and its wide implementation would require a long-term training program, but it seems that it could be an impulse that would significantly improve survival in this group of patients.

Impacto das superfícies de compressão na massagem cardíaca durante a reanimação cardiopulmonar: uma revisão integrativa / Impacto de las superficies de compresión en el masaje cardíaco durante la reanimación cardiopulmonar: una revisión integrativa / Impact of compression surfaces on cardiac massage during cardiopulmonary reanimation: an integrative review

Resumo Objetivo sintetizar as evidências disponíveis na literatura sobre os tipos de superfícies de compressão utilizadas na RCP e analisar quais características das superfícies de compressão têm impacto na eficácia da compressão torácica durante a RCP. Método revisão integrativa da literatura, cujos critérios de seleção e inclusão foram: artigos completos, em inglês, português ou espanhol e que respondessem a seguinte questão de pesquisa: "Quais são as características das superfícies de compressão que têm impacto na eficácia das compressões torácicas durante a RCP?". Realizada entre os meses de junho e julho de 2019. Resultados inclui-se 12 artigos de estudos experimentais, cuja extração de dados revelou 13 tipos diferentes de colchões. Em relação às pranchas, seis tamanhos diferentes foram relatados, com diferentes materiais. Constatou-se influências do tipo de superfície de compressão na força necessária para realizar as compressões torácicas. Conclusão as evidências apontam que colchões de maiores dimensões e com tecnologia para redução de pressão e camas mais largas apresentam impactos negativos na qualidade das compressões torácicas. Implicação para prática o conhecimento sobre a influência do tipo e características das superfícies de apoio na qualidade das compressões torácicas podem subsidiar profissionais na escolha e incorporação de tecnologias no ambiente hospitalar.

Resumen Objetivo Sintetizar la evidencia disponible en la literatura sobre los tipos de superficies de compresión utilizadas en la RCP y analizar qué características de las superficies de compresión tienen un impacto en la efectividad de la compresión torácica durante la RCP. Método Revisión bibliográfica integradora, cuyos criterios de selección e inclusión fueron: artículos completos, en inglés, portugués o español y que respondieran a la siguiente pregunta de investigación: "¿Cuáles son las características de las superficies de compresión que inciden en la efectividad de las compresiones torácicas durante la RCP?". Se llevó a cabo entre junio y julio de 2019. Resultados se incluyeron 12 artículos de estudios experimentales, cuya extracción de datos reveló 13 tipos diferentes de colchones. En cuanto a los Tabelaros, se reportaron seis tamaños diferentes, con diferentes materiales. Se encontraron influencias del tipo de superficie de compresión sobre la fuerza requerida para realizar las compresiones torácicas. Conclusión la evidencia señala que los colchones más grandes con tecnología de reducción de presión y las camas más grandes tienen impactos negativos en la calidad de las compresiones torácicas. Implicación para la práctica El conocimiento sobre la influencia del tipo y características de las superficies de apoyo en la calidad de las compresiones torácicas puede ayudar a los profesionales en la elección e incorporación de tecnologías en el ámbito hospitalario.

Abstract Objective To synthesize the available evidence in the literature on the types of compression surfaces used in CPR and to analyze which characteristics of the compression surfaces impact the effectiveness of chest compression during CPR. Method Integrative literature review, whose selection and inclusion criteria were complete articles, in English, Portuguese or Spanish and that answered the following research question: "What are the characteristics of the compression surfaces that impact the effectiveness of chest compressions during CPR?". It was carried out between June and July 2019. Results 12 articles from experimental studies were included. 13 different types of mattresses were found. Regarding the boards, six different sizes and many materials were reported. Influences of the type of compression surface on the force required to perform chest compressions were found. Conclusion Evidence points out that larger mattresses with pressure reduction technology and larger beds have negative impacts on the quality of chest compressions. Implication for practice Knowledge about the influence of the type and characteristics of support surfaces on the quality of chest compressions can support professionals in the choice and incorporation of technologies in the hospital environment.

Full recovery after 45 min of open cardiac massage for penetrating trauma: Resuscitation guided by end tidal CO2 and permissive hypotension.

We present a rare case of a patient who sustained a gunshot wound to the abdomen, injuring the aorta, IVC and right common iliac vein. After initially obtaining return of spontaneous circulation (ROSC) en route to the hospital, the patient again lost cardiac activity in the operating room during exploratory laparotomy. Resuscitative thoracotomy was performed and open cardiac massage was maintained for approximately 45 min while vessel injuries were repaired. During cardiac massage, end tidal CO2 was maintained between 15 and 31 mm Hg with 100% oxygen saturation and the patient received on-going transfusion of recycled whole blood and blood component therapy. Permissive hypotension was maintained to facilitate rapid repair of major vessels. Return of spontaneous circulation was achieved with a single 30 joule defibrillation. The patient was discharged home on hospital day 11, neurologically intact. This is the first report of survival after 45 min of open cardiac massage with aortic cross clamping, indicating that end tidal CO2 may act as an indicator of adequate end organ perfusion during protracted periods of hypotension.

[Complication of a successful cardiopulmonary resuscitation]. / Cas clinique. Complication d'une réanimation cardiopulmonaire réussie.

A case of bilateral extensive subcutaneous emphysema secondary to external cardiac massage is reported. This is a rare complication. It occurs with a pneumothorax after resuscitation maneuvers. The diagnosis is based on a bundle of anamnestic, clinical and radiological arguments. This case demonstrates the importance of performing a simple prehospital thoracostomy on the finger without chest tube placement and demonstrates the need for systematic investigation of possible complications in any patient who has undergone external cardiac massage.

Un cas d'emphysème sous-cutané, extensif, bilatéral, consécutif à un massage cardiaque externe, est rapporté. Il s'agit d'une complication rare. Celle-ci survient avec un pneumothorax après les manœuvres de réanimation. Le diagnostic est basé sur un faisceau d'arguments anamnestiques, cliniques et radiologiques. Ce cas montre l'importance de la réalisation d'une thoracostomie préhospitalière simple, au doigt, sans pose de drain thoracique et démontre la nécessité de la recherche systématique de complications éventuelles chez tout malade ayant subi un massage cardiaque externe en cas de dégradation clinique.

Avaliação do impacto das superfícies de compreensão na força necessária para compreensão torácica de alta qualidade / Impact evaluation of compression surfaces on the force required for high-quality chest compression

Introdução: A ressuscitação cardiopulmonar (RCP), em especial, a compressão torácica de alta qualidade é fundamental para a sobrevivência de pacientes vítimas de parada cardiorrespiratória (PCR) intra e extra-hospitalar. Um ponto importante a ser considerado é que não existem recomendações relativas às especificidades da execução das manobras de RCP em condições hospitalares, onde os pacientes estão alocados em superfícies que podem interferir na qualidade das compressões torácicas. Estudos experimentais mostram que a qualidade das compressões torácicas pode variar em cenários da vida real devido a diferenças ambientais e características das superfícies. São consideradas superfícies de compressão o colchão onde o paciente estiver deitado, o chão, a cama/maca e a superfície rígida/ prancha. Essas superfícies de compressão apresentam variáveis que podem impactar o atingimento (alcance) da profundidade adequada na compressão torácica. Objetivos: Mensurar o impacto das diferentes superfícies de compressão (cama/maca, colchão e prancha rígida) sobre a força necessária para realizar compressão torácica de alta qualidade; correlacionar as características das superfícies de compressão (cama/maca, colchão e prancha rígida) com a força necessária para realizar compressão torácica de alta qualidade e identificar um modelo de regressão que possa relacionar, conjunta ou isoladamente, as diferentes superfícies de compressão com a força necessária para realizar compressão torácica de alta qualidade. Metodologia: Trata-se de um estudo experimental, de abordagem quantitativa, onde foi investigado o impacto das características das superfícies de compressão na força necessária para uma compressão torácica de alta qualidade realizado com manequim do tipo Little Anne e um equipamento construído para execução das compressões torácicas. Resultados: Foram realizados 230 testes experimentais que mediram a força necessária para uma compressão torácica de alta qualidade incluindo a variação de 2 fatores: conjunto de cama/maca + colchão e presença ou ausência de prancha rígida. Cinco destes testes foram realizados numa mesa de mármore, simulando o chão, que foi usada como padrão ouro para este estudo. A prancha de madeira apresentou o melhor resultado estatístico para força necessária para uma compressão torácica de alta qualidade, comparada às de acrílico, cabeceira removível do leito e sem a utilização da prancha rígida. As dimensões da cama e, principalmente, as características dos colchões estão correlacionadas estatisticamente com a força necessária para a compressão torácica de alta qualidade, indicando que maiores dimensões da cama e de colchões estão relacionadas à maior força necessária para a compressão torácica ideal e vice-versa. Conclusão: Este estudo atingiu seu objetivo permitindo medir o impacto das superfícies de compressão sobre a força necessária para atingir uma compressão torácica ideal, assim como correlacionar com as dimensões e características das camas/macas, colchões e pranchas rígidas, possibilitando a reflexão das equipes de saúde sobre um atendimento de RCP no que tange ao impacto dessas superfícies sobre a força necessária para se alcançar uma compressão torácica de alta qualidade. Os resultados da análise de regressão confirmam que nenhuma das medidas da prancha rígida é significativa para a força necessária para compressão torácica de alta qualidade. Foram investigados 8.190 modelos de regressão com as possíveis combinações das variáveis da cama/maca, colchão e prancha rígida e não foi possível modelar a força necessária para a compressão torácica de alta qualidade com as dimensões estudadas utilizadas neste trabalho.

Introduction: Cardiopulmonary resuscitation (CPR), particularly the high-quality chest compression, is essential for patient's survival who are victims of cardiopulmonary arrest (CPA) inside and outside hospitals. An important point to be considered is that there are no recommendations regarding specifics CPR maneuvers in hospital conditions, where patients are placed on surfaces that can interfere in the quality of chest compressions. Experimental studies show that the quality of chest compressions can vary in real-life settings due to environmental differences and surface characteristics. Compression surfaces considered are the mattress where the patient is lying, the floor, the bed / stretcher, and the rigid surface / board. These compression surfaces have variables that can impact reaching (reach) the appropriate depth in chest compression. Objectives: Measure the impact of the different compression surfaces (bed / stretcher, mattress and rigid board) on the force required to perform high-quality chest compression; correlate the characteristics of the compression surfaces (bed / stretcher, mattress and rigid board) with necessary strength to perform high- quality chest compression and identify a regression model that can relate, jointly or separately, the different compression surfaces to the necessary force to perform high-quality chest compression. Methodology: This is an experimental study, with a quantitative approach, in which the impact of the compression surfaces' characteristics on the necessary force for high-quality chest compression performed with a Little Anne mannequin and equipment built to perform compressions was investigated. Results: 230 experimental tests were carried out to measure the strength required for high-quality chest compression including the variation of 2 factors: bed / stretcher set + mattress and the presence or absence of a rigid board. Five tests were performed on a marble table, simulating the floor, which was used as the gold standard for this study. The wooden plank presented the best statistical result for the necessary strength for a high-quality chest compression, compared to acrylic, removable headboard and without the use of the rigid plank. The bed's dimensions and, mainly, the mattresses' characteristics are statistically correlated with the necessary force for high-quality chest compression, indicating that larger dimensions of bed and mattresses are related to the greater force necessary for the ideal compression and vice- versa. Conclusion: This study achieved its objective allowing to measure the impact of the compression surfaces on the necessary force to achieve an ideal chest compression, as well as to correlate with the dimensions and characteristics of the beds / stretchers, mattresses and rigid boards, allowing the reflection for the health teams on a CPR service regarding the impact of these surfaces on the necessary force to achieve high-quality chest compression. The regression analysis' results confirm that none of the rigid board's measurements is significant to the strength required for high-quality chest compression. 8,190 regression models were investigated with the possible combinations of bed / stretcher, mattress, and rigid board variables, and it was not possible to model the strength required for high-quality chest compression with the studied dimensions used in this work.

Kinetics of manual and automated mechanical chest compressions.

AIM: Early onset of adequate chest compression is mandatory for cardiopulmonary resuscitation (CPR) following cardiac arrest. Transmission of forces from chest strain to the heart may be variable between manual and mechanical chest compressions. Furthermore, automated mechanical chest devices can deliver an active decompression, thus improving the venous return to the heart. This pilot study investigated the kinetics of cardiac deformation during these two CPR methods. METHODS: Transesophageal echocardiographic analysis of the right ventricular wall behind the sternum during CPR was assessed during manual and mechanical chest compression in adult patients admitted to the emergency department for out-of-hospital cardiac arrest. RESULTS: 9 patients had manual and 11 mechanical chest compression. Mechanical chest compression was characterized by greater right ventricular lateral wall displacement [with a median (IQR) of 3.7 (3.12-4.27) vs. 2.53 (2.27-2.6) cm, p < 0.0001], and lower rising time [123 (102-169) vs. 187 (164-215) ms, p = 0.002], relaxing time [109 (102-127) vs. 211 (133-252) ms, p = 0.0003], compression rate [100.6 (99.6-102.2) vs. 131.9 (125.4-151.4) bpm, p < 0.0001], with compression-decompression time ratio of [1.04 (0.86-1.1) vs. 0.86 (0.78-0.96), p = 0.046]. CONCLUSION: Mechanical compared to manual chest compression delivered a more rapid compression and decompression of the cardiac structures at an adequate rate, with broader inward-outward movement of the ventricular walls suggesting greater emptying and filling of the ventricles. Transesophageal echocardiography may be a useful tool to assess the adequacy of chest compression without CPR interruption.

Association between left ventricular outflow tract opening and successful resuscitation after cardiac arrest.

BACKGROUND: Survival after cardiac arrest depends on adequate cardiopulmonary resuscitation (CPR). Manual or mechanical external chest compression may be ineffective to restore circulation: structures subjected to external chest compression may differ in forces transfer to intrathoracic structures due to anatomic characteristics and physiological changes. This clinical study aims to assess the association of trans-oesophageal findings during CPR and successful resuscitation. METHODS: Retrospective cohort study. Trans-oesophageal assessment of right ventricular fractional area change, right ventricular outflow tract fractional shortening, left ventricular volumes, ejection fraction, and aortic diameters were performed in refractory out-of-hospital cardiac arrest patients admitted to emergency department for extracorporeal CPR. RESULTS: 19 patients were analyzed. 15 of 19 patients (79%) received venous-arterial extracorporeal membrane oxygenation support. Resuscitation was successful with return of spontaneous circulation or electromechanical activity in 7 patients (group-SUXX) and failed in 12 patients (group-FAIL). 6 patients (32%) were alive at 24 h from the cardiac arrest, one patient (5%) survived to hospital discharge. Left ventricular outflow tract (LVOT) was open during CPR in all patients in group-SUXX and in 1 patient in group-FAIL (p 0.0002). None of the patients with closed LVOT had successful resuscitation. Patients in group-SUXX had a higher ejection fraction (p 0.03), ascending aortic diameter (p 0.04), and survival rate than those in group-FAIL (p 0.015). In a multiple variable Cox's proportional model LVOT opening was the only variable associated with successful resuscitation. CONCLUSIONS: Trans-oesophageal echocardiography can be useful in the emergency setting of cardiopulmonary arrest for discriminating between successful and failing resuscitation.

Outcomes and indications for emergency thoracotomy after adoption of a more liberal policy in a western European level 1 trauma centre: 8-year experience.

The role of emergency thoracotomy (ET) in blunt trauma is still a matter of debate and in Europe only a small number of studies have been published. We report our experience about ET both in penetrating and blunt trauma, discussing indications, outcomes and proposing an algorithm for patient selection. We retrospectively analysed patients who underwent ET at Maggiore Hospital Trauma Center over two periods: from January 1st, 2010 to December 31st, 2012, and from January 1st, 2013 to May 31st, 2017. Demographic and clinical data, mechanism of injury, Injury Severity Score, site of injury, time of witnessed cardiac arrest, presence/absence of signs of life, length of stay were considered, as well as survival rate and neurological outcome. 27 ETs were performed: 21 after blunt trauma and 6 after penetrating trauma. Motor vehicle accident was the main mechanism of injury, followed by fall from height. The mean age was 40.5 years and the median Injury Severity Score was of 40. The most frequent injury was cardiac tamponade. The overall survival rate was 10% during the first period and 23.5% during the second period, after the adoption of a more liberal policy. No long-term neurological sequelae were reported. The outcomes of ET in trauma patient, either after penetrating or blunt trauma, are poor but not negligible. To date, only small series of ET from European trauma centres have been published, although larger series are available from USA and South Africa. However, in selected patients, all efforts must be made for the patient's survival; the possibility of organ donation should be taken into consideration as well.

Intrathoracic Airway Closure Impacts CO2 Signal and Delivered Ventilation during Cardiopulmonary Resuscitation.

RATIONALE: End-tidal CO2 (EtCO2) is used to monitor cardiopulmonary resuscitation (CPR), but it can be affected by intrathoracic airway closure. Chest compressions induce oscillations in expired CO2, and this could reflect variable degrees of airway patency. OBJECTIVES: To understand the impact of airway closure during CPR, and the relationship between the capnogram shape, airway closure, and delivered ventilation. METHODS: This study had three parts: 1) a clinical study analyzing capnograms after intubation in patients with out-of-hospital cardiac arrest receiving continuous chest compressions, 2) a bench model, and 3) experiments with human cadavers. For 2 and 3, a constant CO2 flow was added in the lung to simulate CO2 production. Capnograms similar to clinical recordings were obtained and different ventilator settings tested. EtCO2 was compared with alveolar CO2 (bench). An airway opening index was used to quantify chest compression-induced expired CO2 oscillations in all three clinical and experimental settings. MEASUREMENTS AND MAIN RESULTS: A total of 89 patients were analyzed (mean age, 69 ± 15 yr; 23% female; 12% of hospital admission survival): capnograms exhibited various degrees of oscillations, quantified by the opening index. CO2 value varied considerably across oscillations related to consecutive chest compressions. In bench and cadavers, similar capnograms were reproduced with different degrees of airway closure. Differences in airway patency were associated with huge changes in delivered ventilation. The opening index and delivered ventilation increased with positive end-expiratory pressure, without affecting intrathoracic pressure. Maximal EtCO2 recorded between ventilator breaths reflected alveolar CO2 (bench). CONCLUSIONS: During chest compressions, intrathoracic airway patency greatly affects the delivered ventilation. The expired CO2 signal can reflect CPR effectiveness but is also dependent on airway patency. The maximal EtCO2 recorded between consecutive ventilator breaths best reflects alveolar CO2.