of COVID‐19 infection. As the prevalence of the disease is unknown in most locations, all patients should be treated as if they are high risk. When BLS is being carried out, either a facemask or cloth covering the mouth and nose of both rescuer and patient may reduce the risk of transmission, and guidelines suggest that passive oxygenation using a facemask set on 10 L/min is a useful addition [80, 83]. Some EMS guidelines have recommended the use of a non‐rebreather mask set on 6 L/min and a surgical mask placed over the mask [92]. When self‐inflating bag‐valve‐mask ventilation is considered necessary, there should be a tight seal to the face ideally maintained by a two‐handed grip, and a compression : ventilation ratio of 30 :2 delivered with the rescuer on chest compressions turning to squeeze the bag [80, 83].
Although the 2015 ILCOR guidelines suggested that bag‐valve‐mask ventilation, supraglottic airway, or tracheal intubation were all acceptable, potential COVID‐19 infection now means that tracheal intubation should be performed as soon as possible by the most experienced operator, to minimize complications and time spent exposed to aerosols. Video laryngoscopy is recommended if available, and chest compressions should be paused for intubation attempts. Once a cuffed tube is successfully inserted and a closed circuit has been established, any disconnection should be minimized, and waveform capnography should be used to monitor endotracheal tube placement and CPR quality. Positive pressure ventilation should only be delivered, if possible, after a tracheal tube has been inserted with the cuff inflated, a high‐efficiency particulate air filter connected, and correct placement confirmed.
Defibrillation is not considered an aerosol‐generating procedure, and AHA guidelines suggest that single shocks be delivered as part of the standard advanced cardiac life support algorithm. However, UK and European guidelines advise the use of three stacked shocks at the start of the algorithm, while waiting for other team members to don aerosol PPE [81, 93]. In 2015 ILCOR advised the use of single shocks in order to minimize interruptions in chest compressions [86]. However, as CPR is recognized as an aerosol‐generating procedure and defibrillation is not, it seems reasonable to attempt to treat a shockable rhythm as vigorously as possible while still maximizing rescuer protection.
Reversible causes of cardiac arrest should be sought and treated, bearing in mind that a patient may have had a cardiac arrest because of COVID‐19, or for other reasons while still being infected with the coronavirus. If treatable reversible causes of cardiac arrest have been addressed, stopping CPR early should be considered [81].
At the end of resuscitation attempts, all personnel should remove the PPE carefully and perform hand hygiene. EMS personnel should observe each other while removing PPE to monitor for possible breaches in infection control procedures [83].
Concerns about ALS delivery during the era of COVID‐19 have centered largely on airway management, undoubtedly providing important lessons for the future. In the case of cardiac arrest, however, there remains conflicting evidence about the benefits of various airway management strategies (see Chapter 13). For example, a Japanese study of 650,000 OHCA patients revealed that conventional bag‐valve‐mask ventilation was associated with better odds of neurologically favorable survival compared with any advanced airway [94]. Inconsistent conclusions among research studies result in challenges when developing systematic approaches to new considerations, such as risks associated with COVID‐19.
Post‐Resuscitation Care
Post‐resuscitation care and in‐hospital post‐arrest therapies are an important factor affecting survival after OHCA and subsequent functional outcome [95]. Significant morbidity and mortality after OHCA are due to cerebral and cardiac dysfunction in what has been termed the ‘post‐cardiac arrest syndrome’ [96]. Despite initial coma after OHCA, subsequent neurologic recovery can be influenced by in‐hospital post‐arrest treatments [97–99].
In 2015, ILCOR recommended avoiding hypoxia and hyperoxia in adults with return of spontaneous circulation (ROSC) after cardiac arrest. Patients should receive 100% inspired oxygen until either the arterial oxygen saturation or the partial pressure of arterial oxygen can be measured reliably [86]. partial pressure of carbon dioxide should be maintained within a normal physiological range.
Post‐resuscitation care should be tailored to hemodynamic goals, including mean arterial pressure and systolic blood pressure. Targets are patient specific. The AHA recommends avoidance or correction of hypotension, previously defined as systolic blood pressure greater than 90 mmHg or mean arterial pressure less than 65 mmHg. Prophylactic administration of antiarrhythmic drugs after ROSC is not recommended.
ILCOR recommends targeted temperature management, maintaining a constant temperature between 32 and 36 degrees C, in adults after ROSC from both shockable and non‐shockable rhythms, and the avoidance or treatment of fever after this [86]. They recommend that targeted temperature management is maintained for at least 24 hours post‐ROSC, but routine prehospital initiation with large volumes of cold intravenous fluid should not take place. Finally, they recommend against both routine seizure prophylaxis, although seizures should be treated, and modification of standard glucose management protocols.
Role of the Medical Director
Stewart commented, “Without dedicated medical leadership, the EMS system of a community flirts with mediocrity” [100]. The medical director plays a pivotal role in community systems of cardiac arrest care. It is the medical director’s responsibility to ensure that all components of the system are in place. The importance of medical director involvement cannot be overemphasized. Indeed, Williams et al. showed significant variation in EMS scope of practice with varying involvement of a medical director, and Greer showed that EMS agencies with paid medical directors or agencies with medical director interaction with EMTs in the preceding 4 weeks were more likely to have prehospital cardiovascular procedures in place [101, 102].
Training and Equipment
Cardiac arrest resuscitation requires timely and accurate execution of interventions. Because of the multitude of simultaneous tasks, cardiac arrest resuscitation requires a carefully coordinated team effort, potentially between rescuers from different agencies. EMS personnel should regularly train for cardiac arrest situations to determine the most efficient ways to carry out protocols. When possible, such training should involve the first‐responders who may also attend these incidents. Recent studies of medical emergency team training in simulation settings demonstrate the importance of teamwork and assigned roles [103, 104].
One systematic review described a lack of well‐designed studies examining the retention of adult ALS knowledge and skills in health care personnel, but commented that the available evidence suggests that ALS knowledge and skills decay by 6 months to 1 year after training, with skills decaying faster than knowledge [105]. Simulation has been shown to be superior in the development and maintenance of skills in cardiac arrest management. Learner satisfaction and competency outcomes favor simulation over non‐simulation teaching. Simulation‐based training for resuscitation is highly effective, particularly if employing strategies such as team/group dynamics, distraction, and integrated feedback [106].
Team training, particularly using simulation, may be helpful in improving safety and reducing anxiety among team members. For example, although defibrillator charging during chest compressions poses little risk, rescuers often do not follow the practice because of safety concerns [107].
EMS personnel must possess the equipment necessary to carry out cardiac arrest resuscitation. Key resuscitation equipment includes monitor‐defibrillators, airway management tools, vascular access equipment, and appropriate medications. Cardiac monitors that record and provide real‐time chest compression feedback are preferable, as are monitors that are able to use dynamic filtering to remove compression artifact and reveal
