The use of laryngeal tube by nurses in out-of-hospital emergencies: preliminary experience

In out-of-hospital emergencies, including cardiac arrest, securing the airway and providing adequate lung ventilation are of paramount importance. Tracheal intubation is perceived as the gold standard technique and it is recommended by International Guidelines, but non skilled personnel often find the procedure difficult to achieve. Supraglottic devices are a good alternative in these situations, because they are superior to a bag-valve-mask for lung ventilation and offer better protection from aspiration. We have tested the laryngeal tube (LT) in out-of-hospital emergencies by minimally trained nurses. The LT was placed in 30 patients in cardiac arrest. LT insertion was successful within two attempts in 90% of patients, and ventilation was adequate in 80% of cases. No regurgitation occurred in any patient. The laryngeal tube remained in the correct position throughout resuscitation attempts in 93.3% of cases, while in two patients (6.6%) it became dislodged. In a subjective evaluation of the manoeuvre by nurses (ease of insertion, adequacy of ventilation, protection from aspiration), 86.7% of them expressed a positive opinion. The laryngeal tube appeared to be a reliable device for nurses to manage the airway in out-of-hospital emergencies.     

Recommendations of the international guidelines 2000 conference on cardiopulmonary resuscitation and emergency cardiac care: an overview

The greatest potential for survival of sudden cardiac arrest can be achieved only by providing early intervention using evidence-based therapies that have been studied over time. Emergency cardiac care and the 2000 advanced cardiac life support guidelines encompass all therapies that have been shown to improve outcomes in patients who experience life-threatening events that involve the cardiovascular, cerebrovascular, and pulmonary systems. Early recognition of warning signs, activation of emergency medical systems within the community, basic cardiopulmonary resuscitation, early defibrillation, airway management, and intravenous medication administration are key factors in improving resuscitation outcomes.     

Patients with cardiac arrest are ventilated two times faster than guidelines recommend: An observational prehospital study using tracheal pressure measurement

Aim

To measure ventilation rate using tracheal airway pressures in prehospitally intubated patients with and without cardiac arrest.

Methods

Prospective observational study. In 98 patients (57 with and 41 without cardiac arrest) an air-filled catheter was inserted into the endotracheal tube and connected to a custom-made portable device allowing tracheal airway pressure recording and subsequent calculation of ventilation rate.

Results

In manually ventilated patients with cardiac arrest 39/43 (90%) had median ventilation rates higher than 10/min (overall median 20, min 4, max 74). During mechanical ventilation, 35/38 (92%) had ventilation rates higher than 10/min. The ventilation rate in patients with cardiac arrest was higher than in patients without cardiac arrest, both for manual and mechanical ventilation. Subanalysis comparing episodes with and without compression in cardiac arrest patients showed no clinically significant difference in ventilation rate after compressions were terminated.

Conclusion

Cardiac arrest patients were ventilated two times faster than recommended by the guidelines. Tracheal airway pressure measurement is feasible during resuscitation and may be developed further to provide real-time feedback on airway pressure and ventilation rate during resuscitation.     

Alternative ventilation strategies in cardiopulmonary resuscitation

The introduction of the 2000 Guidelines for Cardiopulmonary Resuscitation emphasizes a new, evidence-based approach to the science of ventilation during cardiopulmonary resuscitation (CPR). New laboratory and clinical science underemphasizes the role of ventilation immediately after a dysrhythmic cardiac arrest (arrest primarily resulting from a cardiovascular event, such as ventricular defibrillation or asystole). However, the classic airway patency, breathing, and circulation (ABC) CPR sequence remains a fundamental factor for the immediate survival and neurologic outcome of patients after asphyxial cardiac arrest (cardiac arrest primarily resulting from respiratory arrest). The hidden danger of ventilation of the unprotected airway during cardiac arrest either by mouth-to-mouth or by mask can be minimized by applying ventilation techniques that decrease stomach gas insufflation. This goal can be achieved by decreasing peak inspiratory flow rate, increasing inspiratory time, and decreasing tidal volume to approximately 5 to 7 mL/kg, if oxygen is available. Laboratory and clinical evidence recently supported the important role of alternative airway devices to mask ventilation and endotracheal intubation in the chain of survival. In particular, the laryngeal mask airway and esophageal Combitube proved to be effective alternatives in providing oxygenation and ventilation to the patient in cardiac arrest in the prehospital arena in North America. Prompt recognition of supraglottic obstruction of the airway is fundamental for the management of patients in cardiac arrest when ventilation and oxygenation cannot be provided by conventional methods. "Minimally invasive" cricothyroidotomy devices are now available for the professional health care provider who is not proficient or comfortable with performing an emergency surgical tracheotomy or cricothyroidotomy. Finally, a recent device that affects the relative influence of positive pressure ventilation on the hemodynamics during cardiac arrest has been introduced, the inspiratory impedance threshold valve, with the goal of maximizing coronary and cerebral perfusion while performing CPR. Although the role of this alternative ventilatory methodology in CPR is rapidly being established, we cannot overemphasize the need for proper training to minimize complications and maximize the efficacy of these new devices.     

心肺脑复苏成功的相关因素分析

目的:探讨脑复苏与心肺复苏开始时间、早期除颤、病发场所、年龄、通气方式等相关因素临床意义.方法:回顾性分析我科2005年12月-2010年12月因心跳骤停行心肺复苏(CPR)283例的临床资料.结果:283例中心肺脑复苏成功41例,心肺脑复苏成功率与心跳骤停发生场所(院内、院外),CPR开始时间、早期电除颤、气道通气方式、年龄等因素相关.结论:开始心肺复苏时间越早,自主循环恢复时间愈快,GCS评分愈高.     

Subendocardial infarction in two young boys

Two cases of subendocardial infarction noted at autopsy in young boys are reported. Both patients were resuscitated and maintained on ventilation following significant periods of cardiac arrest. Presumably the infarct occurred at the time of arrest, secondary to inadequate myocardial perfusion, and became visible at autopsy because both children were maintained on assisted ventilation long enough for the gross and microscopical changes to develop. The significance of this phenomenon for survivors of successful post cardiac arrest resuscitation is discussed.     

心源性心脏骤停心肺复苏成功的分析

目的分析影响心源性心脏骤停患者心肺复苏成功的临床因素。方法选择该院收治的心源性心脏骤停患者共58例,根据复苏成功与否分成心肺复苏成功组(成功组)22例和心肺复苏失败组(失败组)36例。分析两组患者的临床资料,探讨与心肺复苏成功的相关因素。结果两组患者性别比和发病种类比较,差异无统计学意义(P0.05);成功组患者的年龄和入院时间明显低于失败组,院前给予抢救的比例明显高于失败组,差异均有统计学意义(P0.05)。成功组患者的心脏停搏时间、抢救时间、心肺复苏循环平均次数、肾上腺素剂量和电除颤次数明显低于失败组,应用辅助机械通气的比例明显高于失败组,差异均有统计学意义(P0.05)。结论心肺复苏成功的因素可能与发病年龄、入院时间、院前给予抢救的比例、心脏停搏时间、抢救时间、心肺复苏循环次数、肾上腺素剂量、平均电除颤次数和应用辅助机械通气有关。     

Do we hyperventilate cardiac arrest patients?

INTRODUCTION: Hyperventilation during cardiopulmonary resuscitation is detrimental to survival. Several clinical studies of ventilation during hospital and out-of-hospital cardiac arrest have demonstrated respiratory rates far in excess of the 10 min(-1) recommended by the ERC. We observed detailed ventilation variables prospectively during manual ventilation of 12 cardiac arrest patients treated in the emergency department of a UK Hospital. METHODS: Adult cardiac arrest patients were treated according to ERC guidelines. Ventilation was provided using a self-inflating bag. A COSMOplus monitor (Respironics Inc.) was inserted into the ventilation circuit at the beginning of the resuscitation from which ventilation data were downloaded to a laptop. RESULTS: Data were collected from 12 patients (7 male; age 47-82 years). The maximum respiratory rate was 9-41 breaths per minute (median 26). The median tidal volume was 619 ml (374-923 ml) and the median respiratory rate was 21 min(-1) (7-37 min(-1)). The corresponding median minute volume was 13.0 l/min (4.6-21.3 min(-1)). Median peak inspiratory pressures were 60.6 cmH(2)O (range 46-106). Airway pressure was positive for 95.3% of the respiratory cycle (range 87.9-100%). CONCLUSIONS: Hyperventilation was common, mostly through high respiratory rates rather than excessive tidal volumes. This is the first study to document tidal volumes and airway pressures during resuscitation. The persistently high airway pressures are likely to have a detrimental effect on blood flow during CPR. Guidelines on respiratory rates are well known, but it would appear that in practice they are not being observed.     

Five years experience of cardiopulmonary resuscitation in a children's hospital

The emergency call for resuscitation in a children's hospital is reported. Forty-seven resuscitation attempts via the emergency call were made in 43 patients over the past 5 years; 24 out of 43 patients had heart diseases. Cardiac patients were more likely to die within a few days after their resuscitation. The patients, who had previously been in cardiac arrest, lost their lives more often. These results implied that it was very crucial to prevent cardiac arrest especially for cardiac patients in order to save lives. Among the causes of emergency calls, complications with the endotracheal tubes were most common (13) and the airway obstructions followed (11). Summation of two causes, the airway problems, accounted for more than half of the series. Sixteen out of all emergency calls occurred on weekends, and all endotracheal tube troubles broke out during a night shift or on a holiday, that is, the lives of those patients were threatened especially when fewer staff were on duty. Those accidents were embarrassing for us because we believe that all patients must have been under our surveillance all day. Some hospitals have a successful resuscitation rate, organizing a cardiopulmonary resuscitation (CPR) team. However, we obtained better results (about 30%) without a team. It should be borne in mind that it is more desirable to prevent cardiac or respiratory arrests initially rather than save the patients in emergencies.     

Mise au point sur la réanimation cardio-pulmonaire initiale

Actualisation of the guidelines for cardiopulmonary resuscitation have been recently proposed by the American Heart Association in collaboration with the International Liaison Committee On Resuscitation. It is the opportunity to take stock of the current studies and the main recent improvements achieved in cardiac arrest treatment, in particular for cardiac massage, airway control and ventilation, defibrillation, or use of pharmacologic agents. In the last section of the review, we summarize what we consider to be significant revisions and innovations in resuscitation concepts.     

Pulmonary barotrauma during cardiopulmonary resuscitation

Two cases are presented of pulmonary barotrauma developing during cardiopulmonary resuscitation. This was attributed to high airway pressures developed during ventilation. One patient was ventilated with a self-inflating bag and the second with the Robertshaw demand valve. Both devices were used appropriately. Three other cases of pulmonary barotrauma during resuscitation have been recorded with the use of the latter device during CPR by ambulance personnel in Israel. The Robertshaw demand valve may generate excessively high airway pressures during normal use or when malfunctioning. For these reasons, the use of the Robertshaw demand valve has been discontinued in the Israeli Emergency Medical Services ambulances.     

人工通气在早期心肺复苏中价值的探讨

目的:评价早期心肺复苏(CPR)中A(气道)、B(呼吸)、C(循环)抢救步骤的价值。方法:收集132例心跳、呼吸骤停行CPR患者的临床资料,对43例复苏成功病例,按原发疾病进行分类统计以及实施心肺复苏所采取C、CAB及ABC的步骤,比较各组的成功率。结果:心源性疾患所引起心跳、呼吸骤停C组复苏成功率为50.0％明显高于其他各组(P<0.05)。C组与ABC组比较复苏成功率有显著性差异(P<0.05)。结论:C及CAB是各种原因引起的心跳、呼吸骤停患者CPR中有效的抢救步骤。     

C.A.U.S.E.: Cardiac arrest ultra-sound exam--a better approach to managing patients in primary non-arrhythmogenic cardiac arrest

Cardiac arrest is a condition frequently encountered by physicians in the hospital setting including the Emergency Department, Intensive Care Unit and medical/surgical wards. This paper reviews the current literature involving the use of ultrasound in resuscitation and proposes an algorithmic approach for the use of ultrasound during cardiac arrest. At present there is the need for a means of differentiating between various causes of cardiac arrest, which are not a direct result of a primary ventricular arrhythmia. Identifying the cause of pulseless electrical activity or asystole is important as the underlying cause is what guides management in such cases. This approach, incorporating ultrasound to manage cardiac arrest aids in the diagnosis of the most common and easily reversible causes of cardiac arrest not caused by primary ventricular arrhythmia, namely; severe hypovolemia, tension pneumothorax, cardiac tamponade, and massive pulmonary embolus. These four conditions are addressed in this paper using four accepted emergency ultrasound applications to be performed during resuscitation of a cardiac arrest patient with the aim of determining the underlying cause of a cardiac arrest. Identifying the underlying cause of cardiac arrest represents the one of the greatest challenges of managing patients with asystole or PEA and accurate determination has the potential to improve management by guiding therapeutic decisions. We include several clinical images demonstrating examples of cardiac tamponade, massive pulmonary embolus, and severe hypovolemia secondary to abdominal aortic aneurysm. In conclusion, this protocol has the potential to reduce the time required to determine the etiology of a cardiac arrest and thus decrease the time between arrest and appropriate therapy.     

Efficacy of chest compression-only BLS CPR in the presence of an occluded airway

Reluctance of the lay public to perform bystander CPR is becoming an increasingly worrisome problem in the USA. Most bystanders who admit such reluctance concede that fear of contagious disease from mouth-to-mouth contact is what keeps them from performing basic life support. Animal models of prehospital cardiac arrest indicates that 24-h survival is essentially as good with chest compression-only CPR as with chest compressions and assisted ventilation. This simpler technique is an attractive alternative strategy for encouraging more bystander participation. Such experimental studies have been criticized as irrelevant however secondary to differences between human and porcine airway mechanics. This study examined the effect of chest compression-only CPR under the worst possible circumstances where the airway was totally occluded. After 6 min of either standard CPR including ventilation with a patent airway or chest compressions-only with a totally occluded airway, no difference in 24 h survival was found (10/10 vs. 9/10). As anticipated arterial blood gases were not as good, but hemodynamics produced were better with chest compression-only CPR (P < 0.05). Chest compression-only CPR, even with a totally occluded airway, is as good as standard CPR for successful outcome following 6.5 min of cardiac arrest. Such a strategy for the first minutes of cardiac arrest, particularly before professional help arrives, has several advantages including increased acceptability to the lay public.     

Percutaneous transtracheal emergency ventilation during respiratory arrest: comparison of the oxygen flow modulator with a hand-triggered emergency jet injector in an animal model

The oxygen flow modulator is a device for percutaneous transtracheal emergency ventilation. Simulating a respiratory arrest situation, we studied the effects of this device in comparison with a hand-triggered emergency jet injector during pulmonary resuscitation. Nine pigs were anesthetized and mechanically ventilated. After surgical exposure, an emergency transtracheal airway catheter was inserted into the trachea. Ventilation was stopped until SpO2 was below 70%. Each animal was subsequently randomly ventilated via the transtracheal airway catheter with either the hand-triggered emergency jet injector or the oxygen flow modulator. After 10 minutes, respiratory and hemodynamic parameters were recorded. Ventilation was stopped again until SpO2 reached 70%, and the animal was ventilated with the second device. With both devices, pulmonary resuscitation was successful. Whereas PaO2 differed not significantly between the two devices, PaCO2 was lower during percutaneous transtracheal ventilation with the hand-triggered emergency jet injector.     

The triple work-up for emergency department patients with acute chest pain: how often does it occur?

Background: In 2005, the European Resuscitation Council and the American Heart Association published new guidelines for Advanced Life Support. One of the points was to reduce the time without chest compressions in the first phase of cardiac arrest. Objective: We evaluated in a manikin model whether using the single-use laryngeal tube with suction option (LTS-D) instead of endotracheal intubation (ET) and bag-mask-valve ventilation (BMV) for emergency airway management could reduce the “no-flow time” (NFT). The NFT is defined as the time during resuscitation when no chest compressions take place. Methods: A randomized, prospective study was undertaken with 150 volunteers who performed management of a standardized simulated cardiac arrest in a manikin. Every participant was randomized to one of three different airway management groups (LTS-D vs. ET vs. BMV). Results: The LTS-D was inserted significantly faster than the ET tube (15 s vs. 44 s, respectively, p < 0.01). During the cardiac arrest simulation, establishing and performing ventilation took an average of 57 s with the LTS-D compared to 116 s with ET and 111 s with the BMV. Using the LTS-D significantly reduced NFT compared to ET and the BMV (125 s vs. 207 s vs. 160 s; p < 0.01). Conclusions: In our manikin study, NFT was reduced significantly when the LTS-D was used when compared to ET and BMV. The results of our manikin study suggest that for personnel not experienced in tracheal intubation, the LTS-D offers a good alternative to ET and BMV to manage the airway during resuscitation, and to avoid the failure to achieve tracheal intubation with the ET, and the failure to achieve adequate ventilation with the BMV.     

Analysis of a 2-year-old resuscitation service

The results of attempted resuscitation of 561 patients with cardiac or respiratory arrest are reported. A one-way speech, multiple-call system, and two mobile resuscitation trolleys were used. Most of the patients were between 50 and 80 years of age. Threequarters of the patients presented with cardiac arrest which manifested as asystole almost twice as often as ventricular fibrillation. The commonest causes of arrest were acute myocardial infarction, unknown causes, cardiac failure, recent surgery, and respiratory arrest. Autopsies were obtained in one-third of patients who died. Most calls were between 10.00 hours and 22.00 hours and came from the medical wards. The initial method of assisted ventilation was by endotracheal tube and Ambu-bag in almost one-half of the patients, face mask and Ambu-bag in one-quarter and mouth-to-mouth or mouthto-nose in only one-tenth. A spontaneous electrocardiogram and/or pulse was restored in approximately one-third of patients, spontaneous breathing in 22%, and consciousness in 9%, and 18% returned to their pre-arrest status. Successful resuscitation was achieved in 25% but only 8% survived to leave hospital. Patients with respiratory arrest fared more than twice as well as those with cardiac arrest.The factors relating to successful resuscitation are discussed.     

Periodic acceleration (pGz) CPR in a swine model of asphyxia induced cardiac arrest. Short-term hemodynamic comparisons

BACKGROUND: Asphyxia is one of the most common causes of pediatric cardiac arrest, and becoming a more frequently recognized cause in adults. Periodic acceleration (pGz) is a novel method of cardiopulmonary resuscitation (CPR). pGz is achieved by rapid motion of the supine body headward-footward that generates adequate perfusion and ventilation during cardiac arrest. In a swine ventricular fibrillation cardiac arrest model, pGz produced a higher return of spontaneous circulation (ROSC), superior neurological outcome, less echocardiography evidence of post resuscitation myocardial stunning, and decreased indices of tissue injury. In contrast to standard chest compression CPR, pGz does not produce rib fractures. We investigated the feasibility of pGz in severe asphyxia cardiac arrest and assessed whether beneficial effects seen in the VF model of cardiac arrest could be realized. METHODS AND RESULTS: Sixteen swine weight 4+/-1 kg were anesthetized, tracheally intubated, and instrumented to measure, hemodynamics and echocardiography. Asphyxia was induced by occlusion of the tracheal tube. After loss of aortic pulsations (median time 10 min) animals were observed for three additional minutes following which all were in cardiac arrest. The animals were then randomized to receive 10 min of pGz or standard chest compression ventilation performed with a commercial device (Thumper). A single dose of epinephrine (adrenaline) and sodium bicarbonate were given and defibrillation attempted if appropriate for a maximum of 10 min. Both groups received fractional inspired O2 concentration of 100% during CPR and after resuscitation. Four animals in each group (50%) had an initial ROSC, however only two of the four initial survivors remained alive 3h after ROSC. There were no significant differences in blood pressure, coronary perfusion pressure during CPR and after early ROSC between groups. pGz treated animals had significantly lower pulmonary artery pressure; 20+/-4 mmHg compared to Thumper 46+/-5 mmHg, 30 min after ROSC (p<0.01). Surviving animals in both groups had severe myocardial dysfunction at 30 min after ROSC. At necropsy, 25% of the Thumper treated animals had rib fractures, while none occurred in the pGz group. CONCLUSIONS: In a lethal model of asphyxia cardiac arrest, pGz is equivalent to standard CPR, with respect to acute outcomes and resuscitation survival rates but is associated with significantly lower pulmonary artery pressures and does not produce traumatic rib fractures.     

The Current Crisis in Emergency Care and the Impact on Disaster Preparedness

Background

In 1999, the laryngeal tube (VBM Medizintechnik, Sulz, Germany) was introduced as a new supraglottic airway. It was designed to allow either spontaneous breathing or controlled ventilation during anaesthesia; additionally it may serve as an alternative to endotracheal intubation, or bag-mask ventilation during resuscitation. Several variations of this supraglottic airway exist. In our study, we compared ventilation with the laryngeal tube suction for single use (LTS-D) and a bag-mask device. One of the main points of the revised ERC 2005 guidelines is a low no-flow-time (NFT). The NFT is defined as the time during which no chest compression occurs. Traditionally during the first few minutes of resuscitation NFT is very high. We evaluated the hypothesis that utilization of the LTS-D could reduce the NFT compared to bag-mask ventilation (BMV) during simulated cardiac arrest in a single rescuer manikin study

Methods

Participants were studied during a one day advanced life support (ALS) course. Two scenarios of arrhythmias requiring defibrillation were simulated in a manikin. One scenario required subjects to establish the airway with a LTS-D; alternatively, the second scenario required them to use BMV. The scenario duration was 430 seconds for the LTS-D scenario, and 420 seconds for the BMV scenario, respectively. Experienced ICU nurses were recruited as study subjects. Participants were randomly assigned to one of the two groups first (LTS-D and BMV) to establish the airway. Endpoints were the total NFT during the scenario, the successful airway management using the respective device, and participants' preference of one of the two strategies for airway management

Results

Utilization of the LTS-D reduced NFT significantly (p < 0.01). Adherence to the time frame of ERC guidelines was 96% in the LTS-D group versus 30% in the BMV group. Two participants in the LTS-D group required more than one attempt to establish the LTS-D correctly. Once established, ventilation was effective in 100%. In a subjective evaluation all participants preferred the LTS-D over BMV to provide ventilation in a cardiac arrest scenario

Conclusion

In our manikin study, NFT was reduced significantly when using LTS-D compared to BMV. During cardiac arrest, the LTS-D might be a good alternative to BMV for providing and maintaining a patent airway. For personnel not experienced in endotracheal intubation it seems to be a safe airway device in a manikin use     

Precordial compression without airway management induces lung injury in the rodent cardiac arrest model with central apnea.

To investigate whether the lung injury induced by precordial compression without ventilation or not, in the cardiac-arrest animal model with central apnea. Thirty male Sprague-Dawley rats were anesthetized with halothane. The cardiac arrest was induced by 100 mg/kg ketamine (IV) and accompanied with central apnea. They were allocated to four groups by means of resuscitation. Group A was treated with only precordial compression without the other treatments. In group B with tracheotomy and precordial compression. In group C was performed tracheotomy, oxygenation, and precordial compression. The animals in group D were treated with tracheotomy, oxygen administration, artificial ventilation, and precordial compression. Four minutes after cardiac arrest, the resuscitation was started and continued for 20 min. PaCO(2) in the group without mechanical ventilation increased significantly after the start of the resuscitation. All animals were sacrificed after resuscitation procedure. The wet/dry weight ratio of lung in group A (6.9+/-0.8) was significantly higher than that of the other groups B, C and D (5.9+/-0.6, 5.7+/-0.4 and 5.6+/-0.4, P<0.05 in each). The pathological findings also demonstrated the lung injuries, such as edema, migration, and destruction of structure in group A. The precordial compression alone did not improve CO(2) elimination in the gasping-less cardiac arrest model, as well as maybe inducing more severe lung injury than that with the protective management. This experimental model raises the possibility that chest compressions without airway management might result in lung injury.