LUCAS compression device-related severe injuries in a series of patients presenting with outside hospital cardiac arrest

Abstract

This case series presents patients who presented to the hospital with an outside hospital cardiac arrest and were initially resuscitated successfully. All patients suffered fatal traumatic injuries during the resuscitation process with the common variable being the use of mechanical cardiopulmonary resuscitation (CPR) device. The goal of this case series is to describe the limitations and potential fatal side effects of CPR. We also present a review of literature with our impressions of the appropriate indications for the use of mechanical CPR.

Learning objectives

1) Recognize appropriate indications for the use of mechanical vs manual cardiopulmonary resuscitation (CPR). 2) Identify signs and symptoms of mechanical CPR-related complications.

Introduction

Annually, almost 300,000 patients are treated for outside hospital cardiac arrest (OHCA) in the USA [1]. High quality chest compression is an essential component of cardiopulmonary resuscitation (CPR), and chest compressions of insufficient depth or rate are associated with poor outcomes [2]. Effective CPR can be delivered manually or by means of a mechanical chest compression device. Although chest compression is an integral part of basic life support (BLS) and advanced cardiac life support (ACLS), it portends a risk of iatrogenic skeletal and soft tissue injuries [1]. One of the commonly used devices in the USA is the Lund University Cardiac Assist System (LUCAS). There is no statistical difference reported in the survival or return of spontaneous circulation in manual vs mechanical CPR [3]. However, LUCAS chest compression during CPR has been reported to cause significantly more iatrogenic injury than manual chest compression, potentially contributing to death or severe morbidity [4]. We present a series of patients who presented with OHCA and underwent mechanical CPR. Despite initial successful resuscitation measures, the three patients presented below suffered significant and ultimately fatal traumatic injuries.

Case one

A 61-year-old male presented with OHCA while running with his cross-country team. CPR was initiated immediately in the field. On presentation to the emergency department (ED), the patient remained in refractory ventricular tachycardia arrest. CPR was switched from manual to mechanical using a LUCAS II device, and the patient was placed on venoarterial extracorporeal membrane oxygenation (VA ECMO) in the ED. After return of spontaneous circulation (ROSC), the patient was found to have a large pericardial effusion.

The patient was transferred to the cardiac catheterization laboratory and underwent emergent pericardiocentesis with immediate return of >1 l of fresh blood. On fluoroscopy, a large right-sided hemothorax was noted, and a chest tube was placed, evacuating greater than two liters of fresh blood. Coronary angiogram did not reveal any obstructive coronary artery disease but a free-flowing coronary perforation involving the proximal right coronary artery (RCA) which was treated with a covered stent (Fig. 1). The perforation was sealed effectively with no further spillage into the pericardium, and there was no residual stenosis in the RCA. Despite control of RCA perforation, the patient's hemodynamic status remained unstable with re-accumulation of fluid in the pericardial space.

Fig. 1.

(A) Active extravasation of contrast dye from a coronary perforation involving the proximal right coronary artery. (B) No further spillage of contrast dye after placement of covered stent.

The patient was emergently taken to the operating room for exploration, which revealed a sternal fracture subtending a perforation injury on the free wall of the right ventricle near the right ventricular outflow tract. This was repaired with eventual hemostasis, and the patient was transferred to the intensive care unit for continued management for profound coagulopathy. Despite aggressive resuscitation and blood products, he remained hemodynamically unstable. A computed tomography (CT) scan revealed a left hemothorax, near-complete right lung consolidation, and a mediastinal hematoma. Eventually, in agreement with his family, his care was transitioned to comfort measures only and he passed away. The family declined to proceed with an autopsy.

Case two

A 67-year-old female presented to the ED after suffering a witnessed cardiac arrest. CPR was initiated in the field, and she was transferred to the ED where CPR was switched to mechanical CPR. Post ROSC electrocardiogram was consistent with inferior ST-segment elevation myocardial infarction (Fig. 2). She was emergently transferred to the cardiac catheterization laboratory and underwent primary percutaneous coronary intervention (PCI) of the RCA along with Impella CP (Abiomed, Danvers, MA, USA) insertion for hemodynamic support. Following her PCI, CT scan of her chest was obtained which revealed a large right pneumothorax with total right lung collapse, along with multiple bilateral rib fractures with associated right chest wall hematoma.

Fig. 2.

Chest computed tomography. *Large right pneumothorax with trace right effusion and total right lung collapse.

After transfer to the cardiac care unit, she sustained another cardiac arrest. A chest tube was inserted at the bedside with immediate ROSC and improvement of hemodynamics. Unfortunately, despite chest tube placement, the patient remained severely hypoxemic and acidotic. Hemodialysis was initiated to improve acid-base disturbances. Repeat chest imaging showed severe bilateral lung opacifications concerning for pulmonary contusions vs acute respiratory distress syndrome. The patient's hemodynamics continued to deteriorate with a recurrent arrest and no improvement in ventilation despite paralysis and inhaled nitric oxide. She was not considered an “advanced therapy” candidate and was eventually transitioned to “comfort measures only” and passed away. The family declined autopsy.

Case three

A 52-year-old male with no significant past medical history was presented to the ED after OHCA. Immediate manual CPR was initiated which was later switched to mechanical CPR using a LUCAS II device. Post ROSC electrocardiogram was concerning for large anterior ST-segment elevation myocardial infarction. Given refractory ventricular tachycardia arrest, the patient was emergently transferred to the cardiac catherization laboratory where ECMO was initiated using the LifeSpark system (5320 W 23rd Street Suite #130 St. Louis Park, MN 55416). Post ECMO insertion, he was successfully cardioverted to normal sinus rhythm. Coronary angiography revealed no obstructive coronary artery disease.

After initially acceptable hemodynamics, pump flow decreased progressively due to what was suspected to be hypovolemia secondary to bleeding. Our “Massive transfusion” protocol was instituted, and he underwent a chest, abdominal, and pelvis CT, which revealed a large anterior mediastinal hematoma extending into the lower neck soft tissues, with active extravasation in the anterior mediastinum. Cardiovascular surgery was consulted but turned the patient down.

Despite ongoing blood transfusions, the patient's status continued to deteriorate, and after discussing with the family, he was transitioned to comfort care and expired. On autopsy, multiple bilateral rib fractures were found, along with a transverse sternal fracture and bilateral internal mammary arteries laceration, associated with extensive anterior mediastinal soft tissue hemorrhages extending to bilateral apical pleural surfaces and involving the soft tissue of the neck (Fig. 3).

Fig. 3.

(A) Mediastinal hematoma due to lacerated internal mammary arteries (arrow). (B and C) Computed tomography of the chest showing *large mediastinal hematoma compressing the right ventricle.

Discussion

This case series involves patients who presented to the hospital with OHCA and were initially resuscitated successfully. All our patients, however, suffered fatal traumatic injuries during the resuscitation process, with the common variable being the use of mechanical CPR devices. Our goal is to describe the limitations and potentially fatal side effects of mechanical CPR, integrating a brief review of the literature with our impressions of the appropriate indications for its use.

Prior literature has reported serious life-threatening injuries in 0–6 % of cases after manual CPR and in 1–7 % of cases after LUCAS CPR [5]. Kralj et al. reported that 30/2148 (1.4 %) of non-survivors autopsied after CPR were judged to have iatrogenic CPR-related injuries that had contributed to death including massive bleeding with >500 ml of blood loss [7]. Friberg et al. noted that 18 of the 38 cases with severe or presumably life-threatening soft tissue injuries presented with damage to the cardiovascular system, e.g. myocardial rupture, aortic rupture, and hemopericardium. Comparing other soft tissue injuries, liver laceration has been found in 4.1 % of cases, which compares to 1.9 % in the manual CPR group [6].

Comparing CPR-related trauma, in a retrospective cohort, Friberg et al. reported that treatment with mechanical chest compressions was more often associated with rib fractures (96 % of cases) and sternal fractures (80 % of cases) than manual chest compressions [4]. However, in a retrospective analysis of an autopsy cohort of >2000 non-survivors after CPR, Kralj et al. found rib and sternal fractures in approximately 79 % and 65 %, respectively, but no increased incidences in the subgroup of patients treated with LUCAS [7].

It is also important to note that despite more efficient CPR, use of automated chest compressions with LUCAS has not been associated with improvement of survival rate in OHCA. The LINC trial found that ROSC was reached 34.6 % in the manual CPR group vs. 35.4 % in the mechanical CPR group [8]. The PARAMEDIC study found that ROSC was achieved in 31 % patients who underwent manual CPR vs. 30 % in the mechanical CPR group [9]. Similarly, more recent studies show that the use of automated chest compressions with LUCAS was not associated with improvement of survival rate in OHCA with ROSC achieved by 30.6 % in the non-LUCAS group vs. 25 % in the LUCAS group without statistical significance [3].

Lastly and most interestingly, clinical outcomes with mechanical CPR have also been reported to be inferior to manual CPR. Karasek et al. reported 30-day survival rate of 16.3 % in the non-LUCAS group vs. 5.07 % in the LUCAS group (p = 0.044) [3]. Another recent study reported significantly better outcomes with manual chest compressions with a 30-day survival of 64.2 % in the manual group vs 22.4 % in the mechanical group in patients presenting with a shockable rhythm (p = 0.0001) [10].

Literature has significant variability in the reported rates of CPR-related injuries. This is likely secondary to a heterogeneity of inclusion criteria, population characteristics, and whether injuries were evaluated, clinically, radiographically, or at autopsy. It is also important to note that there are significant ethical, practical, and economical limits to what types of investigations patients may be subjected to post-CPR.

Conclusion

Review of literature suggests that mechanical CPR is not superior to manual CPR and patients who undergo mechanical CPR may have worse 30-day outcomes. Trauma secondary to mechanical CPR can be life-threatening. Therefore, use of mechanical CPR should be reserved to situations where additional manpower might be limited, such as en-route in an ambulance, or during extracorporeal cardiopulmonary resuscitation (ECPR).

Declaration of competing interest

All authors have no actual or potential conflict of interest in relation to this manuscript.