Association of end-tidal carbon dioxide levels during cardiopulmonary resuscitation with survival in a large paediatric cohort.

AIM: To examine the associations between ETCO2, ROSC, and chest compression quality markers in paediatric patients during active resuscitation. METHODS: This was a single-centre cohort study of data collected as part of an institutional prospective quality initiative improvement program that included all paediatric patients who received chest compressions of any duration from January 1, 2013, through July 10, 2018, in the Johns Hopkins Children's Center. Data was collected from Zoll R Series® defibrillators. Events were included if Zoll data files contained both chest compression and ETCO2 data. 2,746 minutes corresponding to 143 events were included in the analyses. RESULTS: The median event ETCO2 for all 143 events was 16.8 [9.3-26.3] mmHg. There was a significant difference in median event ETCO2 between events that achieved ROSC and those that did not (ROSC: 19.3 [14.4-26.6] vs. NO ROSC: 13.9 [6.6-25.5] mmHg; p < 0.05). When the events were based on patient age, this relationship held in adolescents (ROSC: 18.8 [15.5-22.3] vs. NO ROSC: 9.6 [4.4-15.9] mmHg; p < 0.05), but not in children or infants. Median event ETCO2 was significantly associated with chest compression rate less than 140 (p < 0.0001) and chest compression fraction 90-100 (p < 0.0001). CONCLUSIONS: This represents the largest collection of ETCO2 and chest compression data in paediatric patients to date and unadjusted analyses suggests an association between ETCO2 and ROSC in some paediatric patients.

Use of an end-tidal carbon dioxide-guided algorithm during cardiopulmonary resuscitation improves short-term survival in paediatric swine.

AIM: To evaluate an algorithm that uses an end-tidal carbon dioxide (ETCO2) target of ≥ 30 torr to guide specific changes in chest compression rate and epinephrine administration during cardiopulmonary resuscitation (CPR) in paediatric swine. METHODS: Swine underwent asphyxial cardiac arrest followed by resuscitation with either standard or ETCO2-guided algorithm CPR. The standard group received chest compressions at a rate of 100/min and epinephrine every 4 min during advanced life support consistent with the American Heart Association paediatric resuscitation guidelines. In the ETCO2-guided algorithm group, chest compression rate was increased by 10 compressions/min for every minute that the ETCO2 was < 30 torr, and the epinephrine administration interval was decreased to every 2 min if the ETCO2 remained < 30 torr. Short-term survival and physiologic data during active resuscitation were compared. RESULTS: Short-term survival was significantly greater in the ETCO2-guided algorithm CPR group than in the standard CPR group (16/28 [57.1%] versus 4/28 [14.3%]; p = 0.002). Additionally, the algorithm group had higher predicted mean ETCO2, chest compression rate, diastolic and mean arterial pressure, and myocardial perfusion pressure throughout resuscitation. Swine in the algorithm group also exhibited significantly greater improvement in diastolic and mean arterial pressure and cerebral perfusion pressure after the first dose of epinephrine than did those in the standard group. Incidence of resuscitation-related injuries was similar in the two groups. CONCLUSIONS: Use of a resuscitation algorithm with stepwise guidance for changes in the chest compression rate and epinephrine administration interval based on a goal ETCO2 level improved survival and intra-arrest hemodynamics in this porcine cardiac arrest model.

The use of pressure-controlled mechanical ventilation in a swine model of intraoperative pediatric cardiac arrest.

BACKGROUND: Current pediatric resuscitation guidelines suggest that resuscitators using an advanced airway deliver 8-10 breaths per minute while carefully avoiding excessive ventilation. In the intraoperative setting, having a dedicated ventilation rescuer may be difficult because of limited personnel. Continuing pressure-controlled mechanical ventilation during resuscitation for intraoperative cardiac arrest reduces personnel needed and the risk of hyperventilation but might risk hypoventilation during chest compression delivery. AIMS: To determine whether the use of pressure-controlled mechanical ventilation at prearrest settings provides normoxia and normocarbia during resuscitation from cardiac arrest. METHODS: We retrospectively analyzed combined data from preclinical randomized controlled trials. Two-week-old swine (3-4 kg) underwent asphyxia-induced cardiac arrest. Animals were resuscitated with periods of basic and advanced life support. During resuscitation, pressure-controlled mechanical ventilation was delivered at the prearrest respiratory rate, peak inspiratory pressure, and positive end-expiratory pressure. Arterial blood gases were measured prearrest, at 11 minutes of asphyxia, and at 8 and 20 minutes of cardiopulmonary resuscitation. RESULTS: Piglets (n = 154) received pressure-controlled mechanical ventilation before and during cardiopulmonary resuscitation with a peak inspiratory pressure of 14-15 cm H2 O, positive end-expiratory pressure of 4 cm H2 O, 20 breaths/minute, and an inspiratory:expiratory ratio of 1:2. During asphyxia, the arterial blood gas showed the expected severe hypercarbia and hypoxia. Continuing pressure-controlled mechanical ventilation using prearrest parameters and increasing the FiO2 to 1.0 returned the PaCO2 to prearrest levels and slightly increased the partial pressure of arterial oxygen at 8 and 20 minutes of cardiopulmonary resuscitation. CONCLUSION: In this piglet model of resuscitation from asphyxial arrest, pressure-controlled mechanical ventilation during cardiopulmonary resuscitation at the prearrest ventilator settings with an FiO2 of 1.0 provides adequate oxygenation and restores normocarbia. Clinical investigation is warranted to determine the benefits of continuing pressure-controlled mechanical ventilation at prearrest parameters during pediatric cardiopulmonary resuscitation.

Association of diastolic blood pressure with survival during paediatric cardiopulmonary resuscitation.

AIM: To examine the relationship between survival and diastolic blood pressure (DBP) throughout resuscitation from paediatric asphyxial cardiac arrest. METHODS: Retrospective, secondary analysis of 200 swine resuscitations. Swine underwent asphyxial cardiac arrest and were resuscitated with predefined periods of basic and advanced life support (BLS and ALS, respectively). DBP was recorded every 30 s. Survival was defined as 20-min sustained return of spontaneous circulation (ROSC). RESULTS: During BLS, DBP peaked between 1-3 min and was greater in survivors (20.0 [11.3, 33.3] mmHg) than in non-survivors (5.0 [1.0, 10.0] mmHg; p < 0.001). After this transient increase, the DBP in survivors progressively decreased but remained greater than that of non-survivors after 10 min of resuscitation (9.0 [6.0, 13.8] versus 3.0 [1.0, 6.8] mmHg; p < 0.001). During ALS, the magnitude of DBP change after the first adrenaline (epinephrine) administration was greater in survivors (22.0 [16.5, 36.5] mmHg) than in non-survivors (6.0 [2.0, 11.0] mmHg; p < 0.001). Survival rate was greater when DBP improved by ≥26 mmHg after the first dose of adrenaline (20/21; 95%) than when DBP improved by ≤10 mmHg (1/99; 1%). The magnitude of DBP change after the first adrenaline administration correlated with the timetoROSC (r = -0.54; p < 0.001). CONCLUSIONS: Survival after asphyxial cardiac arrest is associated with a higher DBP throughout resuscitation, but the difference between survivors and non-survivors was reduced after prolonged BLS. During ALS, response to adrenaline administration correlates with survival and time to ROSC. If confirmed clinically, these findings may be useful for titrating adrenaline during resuscitation and prognosticating likelihood of ROSC. Institutional Protocol Numbers: SW14M223 and SW17M101.

The Effect of Asphyxia Arrest Duration on a Pediatric End-Tidal CO2-Guided Chest Compression Delivery Model.

OBJECTIVES: To determine the effect of the duration of asphyxial arrest on the survival benefit previously seen with end-tidal CO2-guided chest compression delivery. DESIGN: Preclinical randomized controlled study. SETTING: University animal research laboratory. SUBJECTS: Two-week-old swine. INTERVENTIONS: After either 17 or 23 minutes of asphyxial arrest, animals were randomized to standard cardiopulmonary resuscitation or end-tidal CO2-guided chest compression delivery. Standard cardiopulmonary resuscitation was optimized by marker, monitor, and verbal feedback about compression rate, depth, and release. End-tidal CO2-guided delivery used adjustments to chest compression rate and depth to maximize end-tidal CO2 level without other feedback. Cardiopulmonary resuscitation for both groups proceeded from 10 minutes of basic life support to 10 minutes of advanced life support or return of spontaneous circulation. MEASUREMENTS AND MAIN RESULTS: After 17 minutes of asphyxial arrest, mean end-tidal CO2 during 10 minutes of cardiopulmonary resuscitation was 18 ± 9 torr in the standard group and 33 ± 15 torr in the end-tidal CO2 group (p = 0.004). The rate of return of spontaneous circulation was three of 14 (21%) in the standard group rate and nine of 14 (64%) in the end-tidal CO2 group (p = 0.05). After a 23-minute asphyxial arrest, neither end-tidal CO2 values (20 vs 26) nor return of spontaneous circulation rate (3/14 vs 1/14) differed between the standard and end-tidal CO2-guided groups. CONCLUSIONS: Our previously observed survival benefit of end-tidal CO2-guided chest compression delivery after 20 minutes of asphyxial arrest was confirmed after 17 minutes of asphyxial arrest. The poor survival after 23 minutes of asphyxia shows that the benefit of end-tidal CO2-guided chest compression delivery is limited by severe asphyxia duration.

A National Survey on Interhospital Transport of Children in Cardiac Arrest.

OBJECTIVES: To describe the U.S. experience with interhospital transport of children in cardiac arrest undergoing cardiopulmonary resuscitation. DESIGN: Self-administered electronic survey. SETTING: Pediatric transport teams listed with the American Academy of Pediatrics Section on Transport Medicine. SUBJECTS: Leaders of U.S. pediatric transport teams. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Sixty of the 88 teams surveyed (68%) responded. Nineteen teams (32%) from 13 states transport children undergoing cardiopulmonary resuscitation between hospitals. The most common reasons for transfer of children in cardiac arrest are higher level-of-care (70%), extracorporeal life support (60%), and advanced trauma resuscitation (35%). Eligibility is typically decided on a case-by-case basis (85%) and sometimes involves a short interhospital distance (35%), or prompt institution of high-quality cardiopulmonary resuscitation (20%). Of the 19 teams that transport with ongoing cardiopulmonary resuscitation, 42% report no special staff safety features, 42% have guidelines or protocols, 37% train staff on resuscitation during transport, 11% brace with another provider, and 5% use mechanical cardiopulmonary resuscitation devices for patients less than 18 years. In the past 5 years, 18 teams report having done such cardiopulmonary resuscitation transports: 22% did greater than five transports, 44% did two to five transports, 6% did one transport, and the remaining 28% did not recall the number of transports. Seventy-eight percent recall having transported by ambulance, 44% by helicopter, and 22% by fixed-wing. Although patient outcomes were varied, eight teams (44%) reported survivors to ICU and/or hospital discharge. CONCLUSIONS: A minority of U.S. teams perform interhospital transport of children in cardiac arrest undergoing cardiopulmonary resuscitation. Eligibility criteria, transport logistics, and patient outcomes are heterogeneous. Importantly, there is a paucity of established safety protocols for the staff performing cardiopulmonary resuscitation in transport.

Pilot Study to Compare the Use of End-Tidal Carbon Dioxide-Guided and Diastolic Blood Pressure-Guided Chest Compression Delivery in a Swine Model of Neonatal Asphyxial Cardiac Arrest.

Background The American Heart Association recommends use of physiologic feedback when available to optimize chest compression delivery. We compared hemodynamic parameters during cardiopulmonary resuscitation in which either end-tidal carbon dioxide ( ETCO 2) or diastolic blood pressure ( DBP ) levels were used to guide chest compression delivery after asphyxial cardiac arrest. Methods and Results One- to 2-week-old swine underwent a 17-minute asphyxial-fibrillatory cardiac arrest followed by alternating 2-minute periods of ETCO 2-guided and DBP -guided chest compressions during 10 minutes of basic life support and 10 minutes of advanced life support. Ten animals underwent resuscitation. We found significant changes to ETCO 2 and DBP levels within 30 s of switching chest compression delivery methods. The overall mean ETCO 2 level was greater during ETCO 2-guided cardiopulmonary resuscitation (26.4±5.6 versus 22.5±5.2 mm Hg; P=0.003), whereas the overall mean DBP was greater during DBP -guided cardiopulmonary resuscitation (13.9±2.3 versus 9.4±2.6 mm Hg; P=0.003). ETCO 2-guided chest compressions resulted in a faster compression rate (149±3 versus 120±5 compressions/min; P=0.0001) and a higher intracranial pressure (21.7±2.3 versus 16.0±1.1 mm Hg; P=0.002). DBP -guided chest compressions were associated with a higher myocardial perfusion pressure (6.0±2.8 versus 2.4±3.2; P=0.02) and cerebral perfusion pressure (9.0±3.0 versus 5.5±4.3; P=0.047). Conclusions Using the ETCO 2 or DBP level to optimize chest compression delivery results in physiologic changes that are method-specific and occur within 30 s. Additional studies are needed to develop protocols for the use of these potentially conflicting physiologic targets to improve outcomes of prolonged cardiopulmonary resuscitation.

Membrane Oxygenator Use With Biventricular Assist Device: Facilitation of Support and Lung Recovery.

We present the use of a low-resistance membrane oxygenator (Quadrox D, Maquet) in series with a pulsatile right ventricular assist device (Berlin Heart EXCOR, Berlin Heart) in a patient with biventricular support who required high-frequency oscillatory ventilation (HFOV), due to refractory acute respiratory distress syndrome associated with Cytomegalovirus pneumonia. The high mean airway pressure associated with the use of HFOV resulted in a significant negative impact on left ventricular assist device (LVAD) filling that led to a combined respiratory and metabolic acidosis and the need for vasopressor support. Oxygenator placement enabled transition to conventional ventilation and the discontinuation of vasopressor support. This case demonstrates the feasibility and safety of the use of this lung support system in patients requiring ventricular assist device (VAD) support.

End-Tidal CO2-Guided Chest Compression Delivery Improves Survival in a Neonatal Asphyxial Cardiac Arrest Model.

OBJECTIVES: To determine whether end-tidal CO2-guided chest compression delivery improves survival over standard cardiopulmonary resuscitation after prolonged asphyxial arrest. DESIGN: Preclinical randomized controlled study. SETTING: University animal research laboratory. SUBJECTS: 1-2-week-old swine. INTERVENTIONS: After undergoing a 20-minute asphyxial arrest, animals received either standard or end-tidal CO2-guided cardiopulmonary resuscitation. In the standard group, chest compression delivery was optimized by video and verbal feedback to maintain the rate, depth, and release within published guidelines. In the end-tidal CO2-guided group, chest compression rate and depth were adjusted to obtain a maximal end-tidal CO2 level without other feedback. Cardiopulmonary resuscitation included 10 minutes of basic life support followed by advanced life support for 10 minutes or until return of spontaneous circulation. MEASUREMENTS AND MAIN RESULTS: Mean end-tidal CO2 at 10 minutes of cardiopulmonary resuscitation was 34 ± 8 torr in the end-tidal CO2 group (n = 14) and 19 ± 9 torr in the standard group (n = 14; p = 0.0001). The return of spontaneous circulation rate was 7 of 14 (50%) in the end-tidal CO2 group and 2 of 14 (14%) in the standard group (p = 0.04). The chest compression rate averaged 143 ± 10/min in the end-tidal CO2 group and 102 ± 2/min in the standard group (p < 0.0001). Neither asphyxia-related hypercarbia nor epinephrine administration confounded the use of end-tidal CO2-guided chest compression delivery. The response of the relaxation arterial pressure and cerebral perfusion pressure to the initial epinephrine administration was greater in the end-tidal CO2 group than in the standard group (p = 0.01 and p = 0.03, respectively). The prevalence of resuscitation-related injuries was similar between groups. CONCLUSIONS: End-tidal CO2-guided chest compression delivery is an effective resuscitation method that improves early survival after prolonged asphyxial arrest in this neonatal piglet model. Optimizing end-tidal CO2 levels during cardiopulmonary resuscitation required that chest compression delivery rate exceed current guidelines. The use of physiologic feedback during cardiopulmonary resuscitation has the potential to provide optimized and individualized resuscitative efforts.