Cardiopulmonary resuscitation in the prone position: a systematic review of case series/reports

Abstract Introduction The prone position is frequently adopted for surgical or critically ill patients in intensive care. Cardiorespiratory arrest in these patients may pose an operational challenge, in which delays resulting from mobilization to the supine position culminate in worse outcomes. Objective To provide clinical insight based on the synthesis of evidence from reports or case series on reverse cardiopulmonary resuscitation (reverse CPR) in surgical patients or invasive ventilatory support in severe acute respiratory distress syndrome. Methods This is a systematic review of reports or case series in PubMed, Scopus, Embase, and Google Scholar databases, in addition to a search of the gray literature. Case reports published in any language, reporting at least one case of prone cardiopulmonary resuscitation in patients of any age and in any care context, were considered eligible. Results Thirteen studies of fourteen cases of successful reverse resuscitation were retrieved. Three patients died within 30 days, while the others survived without complications or neurological sequelae. Conclusion Despite limited evidence to support clinical decision-making, prone resuscitation appears to be a feasible alternative in exceptional circumstances, where patient mobilization may result in additional harm, delay or interrupt advanced life support (compressions, high-quality early chest surgery, and defibrillation) or incur occupational risks to the health team.


Introduction
The prone position is commonly used for surgical procedures that require access to posterior anatomical structures of the brain, neck, and spine, as well as the retroperitoneum and upper urinary tract or other posterior structures.1,2 It is also used in intensive care patients with severe acute respiratory distress syndrome (ARDS) on invasive ventilatory support, considered an established evidence-based practice in these cases.3,4 Patients managed in the prone position, either due to acute respiratory failure or during surgery, may suffer cardiac arrest.They may present with hemodynamic instability due to the severity of the underlying disease and multiple organ failure or acute clinical deterioration induced by drugs or vasovagal stimulation, with subsequent cardiac arrest.5-7 When patients suffer cardiac arrest in the prone position, options include placing them in the supine position before initiating cardiopulmonary resuscitation (CPR) or performing CPR in the prone position.8 In the event of cardiac arrest in the prone position, changing to the supine position may not be feasible or promptly executable, i.e., it is not possible to safely and quickly turn the patient.9 Changing to the supine position may require five or six professionals experienced in performing the procedure and take up to five minutes to complete.10 This delay in initiating CPR can be harmful to the patient, increasing the time without blood flow to the brain and coronary arteries, 11 negatively impacting survival and functional prognoses.
Factors such as spinal instability, open surgical wounds, the presence of surgical instruments, the risk of adverse events such as the loss of ventilatory prosthesis or vascular lines, the need for Covid-19-related personal protective equipment and limited staff preclude performing decubitus changes and may result in a delay in resuscitation.In these circumstances, CPR, including electrical therapy (defibrillation), can be performed with the patient in ventral decubitus.10,12,13 The main goals of initiating prone CPR, also known as reverse CPR, are to shorten the no flow time of blood to the heart or brain and apply defibrillation early (when indicated), factors that contribute to decreasing mortality and mitigating neurologic outcomes in survivors.

Results
The search strategy resulted in 29 eligible studies.
After evaluation by two reviewers, 14 studies were considered for inclusion in the present review (Figure 1).
Tables 1 -3 present a summary of the relevant information from the studies.Table 1 lists the selected studies with their respective references and summarizes the information related to case reports of reverse resuscitation, while  all patients.Among the fifteen cases reported, three patients died in less than 30 days.21,30,31 The remaining articles describe the clinical evolution of patients with no neurological complications secondary to cardiac arrest.No adverse events due to resuscitation in the prone position were reported.A critical evaluation of the case reports shows that most studies provided detailed information.
The prevalent cardiac arrest rhythm was asystole, In regard to the appropriate region to apply resuscitation compressions in the prone position, one study showed that the cross-sectional area of the left ventricle is located at most 0 to 2 vertebral segments below the inferior angle of the scapula, meaning that compression in this location may produce better results.13 A number of methods can be used to perform chest compressions in the prone position, including placing the hands on the scapulae and the thoracic spine, with or without counterpressure on the sternum.12 Counterpressure, where the closed fist is positioned between the sternum and the bedside, can optimize resuscitation maneuvers.23 Sternal counterpressure can increase the effectiveness of chest compressions.
The same compression rate (100-120/min) and depth (5-6 cm) as conventional chest compression should be used.36 In young children, compressions are performed using the fingers of one hand on the thoracic spine.24 In the neurosurgical approach, where the surgical wound and/or instruments prevent access the patient to apply compressions, the surgeon can perform a posterior left thoracotomy and direct cardiac compression.37 Another key aspect of conducting CPR is the application of defibrillation in the event of VF or PVT rhythms.For patients in the prone position in cardiac arrest by VF/PVT, defibrillation must be performed in this position because changing decubitus wastes time and reduces the likelihood of successful defibrillation.9,30,38 To apply electrical therapy in the prone position, one of the defibrillator pads is placed in the left fifth intercostal space at the mid-axillary line, while the other is positioned between the tip of the right scapula and the spine.

39
Another technique involves placing one electrode at the left lower sternal border and the other posteriorly below the scapula.40,41 The probability of successful defibrillation and survival after hospital discharge is directly related to the time between the onset of ventricular fibrillation and administration of the first shock.42 A simulation study reported 22 seconds for applying the first defibrillation in prone patients, compared with an average of 108 ± 61 seconds when the patient was mobilized in the supine position before defibrillation.43 Wei et al. 35 compared the effectiveness of supine and prone cardiac compressions in 11 patients who had

2 ) 48 Conclusion
is recommended to determine the effectiveness of chest compressions and CPR duration and confirm the correct position of the orotracheal tube.45 Invasive blood pressure and continuous ETCO 2 monitoring may be helpful to determine if compressions in the prone position are generating adequate perfusion, which may indicate the ideal moment to place the patient in dorsal decubitus.32 Another relevant aspect concerns training professionals to use reverse CPR algorithms.46,47 Familiarizing the teams with the technical aspects of applying compressions and defibrillation to the patient in the prone position may contribute to better compliance rates.5,22,Despite limited evidence to support clinical decisionmaking, reverse CPR may be a feasible alternative in exceptional circumstances when the time required and technical complexity of moving to supine could cause delays, interruption of advanced life support or risks to the healthcare team.

Table 3
20st of the studies identified cases of cardiorespiratory arrest in hemodynamically stable (surgical) patients and not as a result of clinical degeneration and multiple organ failure in critically ill patients.Only one study reported a patient in intensive care.20

Table 1 -
Narrative summary: general study data be11er hemodynamic effects.The prone position also allows greater airway permeability, enhancing perfusion and oxygenation.6,11ReverseCPR generates greater venous return and higher coronary perfusion pressure when compared to the supine position.34,35 FISIOTERAPIA EM MOVIMENTO Physical Therapy in Movement Dalmedico MM et al.Fisioter Mov.2023;36:e36203 5

Table 3 -
JBI Critical Appraisal evaluation Systolic blood pressure increased significantly, from 48 mm/Hg during standard resuscitation to 72 mm/Hg during reverse resuscitation (23 ± 14 mm/Hg).The results were also higher for mean arterial pressure (14 ± 11 mm/Hg) and diastolic arterial pressure (10 ± 12 mm/Hg).However, despite the increase in pressures, no patient experienced ROSC.
Fisioter Mov.2023;36:e36203 7 7 In a clinical simulation with a Laerdal Resusci Anne mannequin, a study conducted with thirty-six nurses showed that appropriate training in reverse CPR, considering the performance of compressions with adequate depth, produced favorable results and adequate hemodynamic and ventilatory effects.44 Additionally, capnography (ETCO