Lynn P. Roppolo

Dispatcher assessments for agonal breathing improve detection of cardiac arrest

AIM OF STUDY To determine if a new protocol can increase the detection of agonal respirations by emergency medical dispatchers and thus the presence of cardiac arrest. METHODS This is a prospective before and after study performed in a large metropolitan city. Cases were identified by review of all cardiac arrests called into a central medical control office. Data were collected through review of tapes and documentation obtained from routine quality assurance audits of these cardiac arrests at the dispatch office as well as reports written by paramedics at the scene of each case. Data were collected for 8 months prior to and 4 months after the implementation of a new dispatcher protocol designed to identify the presence of agonal breathing which included counting the respiratory rate, holding the phone next to the patient, and identifiers used to describe this type of breathing. RESULTS During the 8 months prior to implementation of the new protocol, no patient had agonal respirations detected compared with 22 patients detected in the 4 months after implementation. The percentage of patients who did not have EMD criteria for cardiac arrest, but actually were in cardiac arrest decreased from 28.0% (168/599) to 18.8% (68/362; p=0.0012). Survival to ED admission was similar between the two groups. Bystanders started CPR significantly more frequently after the new protocol was instituted (60.9% before vs. 71.5% afterward, p=0.006). CONCLUSION Introduction of a new 9-1-1 dispatcher assessment protocol to assess for the presence of agonal respirations can significantly increase the detection cardiac arrest over the telephone.

The detrimental effects of ventilation during low-blood-flow states.

Purpose of reviewIn recent years, it has become increasingly apparent that resuscitative ventilatory procedures, classically thought to be life saving, may have profound detrimental effects. Recent findingsMost assisted breathing techniques during resuscitation involve the provision of intermittent positive pressure ventilation to inflate lung zones for erythrocyte oxygenation and clearance of carbon dioxide. A growing number of studies involving low-flow states, however, have demonstrated that provision of overzealous (or even ‘normal’) ventilatory rates with intermittent positive pressure ventilation can significantly diminish both systemic and coronary circulation, most likely through inhibition of venous return. Recent laboratory studies of hemorrhage have shown not only a direct detrimental impact of each positive pressure ventilation breath on coronary perfusion, but also how dramatic improvements in blood flow can be achieved, without loss of oxygenation, by delivering breaths infrequently during such low-flow states. Likewise, in cardiac arrest models, studies have shown that interrupting chest compressions, even to provide breaths, can be extremely deleterious by abruptly (and continually) lowering the aortic pressure head to the coronary arteries, thus impairing restoration of spontaneous circulation. Even with endotracheal intubation and uninterrupted chest compressions, frequent positive pressure ventilation still inhibits circulation during cardiopulmonary resuscitation. Despite directed training, paramedics (and other rescuers) have been shown to still excessively ventilate during cardiac arrest resuscitations. SummaryVentilation can have profound detrimental hemodynamic effects in low-flow states, exacerbating the circulatory compromise. This underappreciated confounding variable may be one of the reasons many clinical trials of resuscitative interventions have failed despite dramatic successes in the laboratory.

Nasotracheal intubation in the emergency department, revisited

This retrospective study was designed to investigate the current practice of nasotracheal intubation (NTI) in the Emergency Department (ED) at the University of California, San Diego Medical Center. Over a 5-year period, 21% (105/501) of patients intubated in the ED had at least one NTI attempt. The most frequent primary diagnoses in these patients included drug overdose, congestive heart failure, and chronic obstructive pulmonary disease. We report an overall NTI success rate of 79% (83/105). Sixty-one percent (64/105) of the patients were nasally intubated on the first NTI attempt. Nasal dilators, topical neosynephrine, and sedation improved NTI success rates. Epistaxis and improper tube position were the most common immediate complications. Sinusitis, pneumonia, and sepsis were the most frequent late complications. Patients receiving thrombolytic therapy were at risk of developing severe epistaxis. A prior history of sinus disease may predispose a nasally intubated patient to sinusitis. The complication rates reported here are similar to those of previous studies. A survey of emergency medicine (EM) residency programs found that EM residents throughout the country perform an average of 2.8 NTIs during their residency training. Thus, there is limited exposure to this intubation technique in EM residency programs. Nasotracheal intubation is a useful alternative to oral intubation, particularly when oral access is compromised. While not the optimal approach, we conclude that NTI is still a valuable method for establishing an airway and should remain among the emergency physicians arsenal of intubation techniques.

Intravenous fluid resuscitation for the trauma patient.

Purpose of reviewAlthough longstanding practice in trauma care has been to provide immediate, aggressive intravenous fluid resuscitation to injured patients with presumed internal hemorrhage, recent experimental and clinical data suggest a more discriminating approach that first considers concurrent head injury, hemodynamic stability, and the presence of potentially uncontrollable hemorrhage (e.g., deep truncal injury) versus a controllable source (e.g., distal extremity wound). Recent findingsThe data suggest that rapid intravenous fluid infusions could be used for patients with isolated extremity, thermal or head injury. However, intravenous fluids should be limited in conditions with potentially uncontrollable internal hemorrhage, and particularly in patients with penetrating truncal injury being transported immediately to a trauma center. Likewise, positive pressure ventilatory support should be limited with severe hemorrhage due to the secondary reductions in venous return off-setting the effects of the fluids. For trauma patients with severe bleeding, there is growing evidence for the increased use of plasma and factor VIIa, as well as tourniquets, intra-osseus devices, and evolving monitoring techniques. SummaryFuture research efforts in trauma should focus on the timing and rate of infusions as well as the concept of infusing alternative intravenous resuscitative fluids such as hemoglobin-based oxygen carriers (HBOCs) and the use of hemostatic agents and special blood products.

Airway management in neurological emergencies

Several neurological conditions may present to the emergency department (ED) with airway compromise or respiratory failure. The severity of respiratory involvement in these patients may not always be obvious. Proper pulmonary management can significantly reduce the respiratory complications associated with the morbidity and mortality of these patients. Rapid sequence intubation (RSI) is the method of choice for definitive airway management in the ED and is used for the majority of intubations. The unique clinical circumstances of each patient dictates which pharmacological agents can be used for RSI. Several precautions must be taken when using these drugs to minimize potentially fatal complications. Noninvasive positive pressure ventilation may obviate the need for intubation in a select population of patients. This article reviews airway management, with a particular emphasis on the use of RSI for common neurological problems presenting to the ED.

Role of rapid sequence induction for intubation in the prehospital setting: helpful or harmful?

Use of rapid sequence induction for intubation was introduced to the prehospital environment in the hope of enhancing patient outcome by improving early definitive airway management. Varying success has been achieved in both air and ground transport emergency medical services systems, but concern persists about the potential to cause patients harm. Individual emergency medical services systems must determine the need for rapid sequence induction for intubation and their ability to implement a rapid sequence induction for intubation protocol effectively with minimal adverse events. Therefore, the value of rapid sequence induction for intubation is dependent on each emergency medical services system design in their ability to establish personnel requirements and ongoing training, expertise in airway management skills, medical direction and supervision, and a quality assurance program. If these principles are strictly adhered to, rapid sequence induction for intubation may be safely used as an advanced airway management technique in the prehospital setting.

Prehospital endotracheal intubation: elemental or detrimental?

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2015 and co-published as a series in Critical Care. Other articles in the series can be found online at http://ccforum.com/series/annualupdate2015. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901.

Retention, retention, retention: targeting the young in CPR skills training!

The usefulness of basic cardiopulmonary resuscitation (CPR) training in school systems has been questioned, considering that young students may not have the physical or cognitive skills required to perform complex tasks correctly. In the study conducted by Fleishhackl and coworkers, students as young as 9 years were able to successfully and effectively learn basic CPR skills, including automated external defibrillator deployment, correct recovery position, and emergency calling. As in adults, physical strength may limit the depth of chest compressions and ventilation volumes given by younger individuals with low body mass index; however, skill retention is good. Training all persons across an entire community in CPR may have a logarithmic improvement in survival rates for out-of-hospital cardiac arrest because bystanders, usually family members, are more likely to know CPR and can perform it immediately, when it is physiologically most effective. Training captured audiences of trainees, such as the entire work-force of the community or the local school system, are excellent mechanisms to help achieve that goal. In addition to better retention with new half hour training kits, a multiplier effect can be achieved through school children. In addition, early training not only sets the stage for subsequent training and better retention, but it also reinforces the concept of a social obligation to help others.

Clinical review: Reappraising the concept of immediate defibrillatory attempts for out-of-hospital ventricular fibrillation

Despite well developed emergency medical services with rapid response advanced life support capabilities, survival rates following out-of-hospital ventricular fibrillation (VF) have remained bleak in many venues. Generally, these poor resuscitation rates are attributed to delays in the performance of basic cardiopulmonary resuscitation by bystanders or delays in defibrillation, but recent laboratory data suggest that the current standard of immediately providing a countershock as the first therapeutic intervention may be detrimental when VF is prolonged beyond several minutes. Several studies now suggest that when myocardial energy supplies begin to dwindle following more prolonged periods of VF, improvements in coronary artery perfusion must first be achieved in order to prime the heart for successful return of spontaneous circulation after defibrillation. Therefore, before countershocks, certain pharmacologic and/or mechanical interventions might take precedence during resuscitative efforts. This evolving concept has been substantiated recently by clinical studies, including a controlled clinical trial, demonstrating a significant improvement in survival when basic cardiopulmonary resuscitation is provided for several minutes before the initial countershock. Although this evolving concept differs from current standards and may pose a potential problem for automated defibrillator initiatives (e.g. public access defibrillation), successful defibrillation and return of spontaneous circulation have been rendered more predictable by evolving technologies that can score the VF waveform signal and differentiate between those who can be shocked immediately and those who should receive other interventions first.

Layperson training for cardiopulmonary resuscitation: When less is better

Purpose of reviewBasic cardiopulmonary resuscitation, including use of automated external defibrillators, unequivocally saves lives. However, even when motivated, those wishing to acquire training traditionally have faced a myriad of barriers including the typical time commitment (3–4 h) and the number of certified instructors and equipment caches required. Recent findingsThe recent introduction of innovative video-based self-instruction, utilizing individualized inflatable manikins, provides an important breakthrough in cardiopulmonary-resuscitation training. Definitive studies now show that many dozens of persons can be trained simultaneously to perform basic cardiopulmonary resuscitation, including appropriate use of an automated external defibrillator, in less than 30 min. Such training not only requires much less labor intensity and avoids the need for multiple certified instructors, but also, because it is largely focused on longer and more repetitious performance of skills, these life-saving lessons can be retained for long periods of time. SummarySimpler to set-up and implement, the half-hour video-based self-instruction makes it easier for employers, churches, civic groups, school systems and at-risk persons at home to implement such training and it will likely facilitate more frequent re-training. It is now hoped that the ultimate benefit will be more lives saved in communities worldwide.