The heart is under the lower third of the sternum. Implications for external cardiac massage

Comparing the two-finger versus two-thumb technique for single person infant CPR: A systematic review and meta-analysis

INTRODUCTION

Current guidelines recommend that single person cardiopulmonary resuscitation (CPR) on an infant should be performed with two-fingers just below the inter-mammillary line with the hand clenched, while two-person CPR should be performed with two-thumbs with the hands encircling the chest. Those recommendations are based on literature that demonstrates higher quality chest compressions with the two-thumb technique, with concerns that this technique may compromise ventilation parameters when performed by the single rescuer. The purpose of this study is to compare the two compression techniques' performance during CPR using both compression and ventilation parameters.

METHODS

We performed a systematic review and meta-analysis of literature identified through a search of PubMed and One-Search comparing the quality of chest compressions and ventilation parameters between the two-thumb and two-finger techniques (Prospero registration # CRD42018087672).

RESULTS

We identified 20 manuscripts examining single person infant CPR that met study criteria, with 16 that included data suitable for meta-analysis. All of the studies included in the analysis were performed on a standardized manikin. Overall, the two-thumb technique resulted in a mean difference of 5.61 mm greater compression depth compared to the two-finger technique, with 36.91% more compressions of adequate depth per national guidelines. Interestingly, ventilation parameters did not differ between the two techniques.

CONCLUSION

While recognizing that the results of this review may differ from actual clinical experience due to the lack of fidelity between manikins and actual human infants, this systematic review with meta-analysis demonstrates that when CPR is performed on a simulated infant manikin by a single rescuer, the two-thumb technique with hands encircling the chest improves chest compression quality and does not appear to compromise ventilation.

Optimum Chest Compression Point for Cardiopulmonary Resuscitation in Children Revisited Using a 3D Coordinate System Imposed on CT: A Retrospective, Cross-Sectional Study

OBJECTIVES

The optimum chest compression site (P_optimum) in children is debated: European Resuscitation Council recommends one finger breadth above the xiphisternal joint, whereas American Heart Association proposes the lower sternal half. Using a coordinate system imposed on CT, we aimed to determine the pediatric P_optimum to maximize stroke volume, the key point for successful cardiopulmonary resuscitation, while minimizing hepatic injury.

DESIGN

Retrospective, cross-sectional study.

SETTING

University hospital.

PATIENTS

Children 1-15 years old who underwent chest CT.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We defined zero point (0, 0) as the center of the xiphisternal joint designating leftward and upward directions of the patients as positive on each axis. P_optimum (x_max. left ventricle, y_max. left ventricle) was defined as the center of the maximum diameter of the left ventricle, whereas P_aorta (x_aorta, y_aorta) as that of the aortic annulus. To compress the left ventricle exclusively, y_max. left ventricle should range above the y coordinate of hepatic dome (y_liver_dome) and below y_aorta. Data were presented as median (interquartile range) and compared among age groups 1.0-5.0, 5.1-10.0, and 10.1-15.0 years using Kruskal-Wallis test. For universal application regardless of age, y coordinates were converted into relative ones with unit of sternal top: 1 unit of sternal top was the y coordinate of the sternal top. A total of 163 patients were enrolled, median age 8.8 year (4.2-14.3 yr). Among age groups, no significant difference was observed in y_max. left ventricle, relative y_max. left ventricle, y_aorta, and y_liver_dome: 1.0 cm (0.1-1.9 cm), 0.10 unit of sternal top (0.01-0.18 unit of sternal top), 0.39 unit of sternal top (0.30-0.47 unit of sternal top), and -0.14 unit of sternal top (-0.25 to -0.03 unit of sternal top), respectively. The probability to compress the left ventricle exclusively was greater than or equal to 96% when placing hand at 0.05-0.20 unit of sternal top. Subgroup analysis demonstrated the following regression equation: x_max. left ventricle (mm) = 0.173 × (height in cm) + 13 (n = 106; p < 0.001; R = 0.278).

CONCLUSIONS

Theoretically, pediatric P_optimum is located 1 cm (or 0.1 unit of sternal top) above the xiphisternal joint.

What to do if A + B doesn't work

The majority of newborn resuscitations require very little beyond simple airway management and assisted ventilation. If cardiovascular collapse is serious enough to warrant additional support, resuscitation algorithms recommend moving to chest compressions and then on to medications and possibly volume replacement if vital signs remain marginal or absent. The evidence base upon which this part of the neonatal resuscitation algorithm is structured is sparse. Chest compressions and medications are rare interventions that do not lend themselves easily to clinical trials. Slowly but surely, however, the genesis of an empirical evidence base for this part of the algorithm is beginning to appear.

A review of approaches to optimise chest compressions in the resuscitation of asphyxiated newborns

OBJECTIVE

Provision of chest compressions (CCs) and/or medications in the delivery room is associated with poor outcomes. Based on the physiology of perinatal asphyxia, we aimed to provide an overview of current recommendations and explore potential determinants of effective neonatal cardiopulmonary resuscitation (CPR): balancing ventilations and CC, CC rate, depth, full chest recoil, CC technique and adrenaline.

DESIGN

A search in the databases MEDLINE (Ovid) and EMBASE until 10 April 2015.

SETTING

Delivery room.

PATIENTS

Asphyxiated newborn infants.

INTERVENTIONS

CCs.

MAIN OUTCOME MEASURES

Haemodynamics, recovery and survival.

RESULTS

Current evidence is derived from mathematical models, manikin and animal studies, and small case series. No randomised clinical trials examining neonatal CC have been performed. There is no evidence to refute a CC to ventilation (C:V) ratio of 3:1. Raising the intrathoracic pressure, for example, by superimposing a sustained inflation on uninterrupted CC, and a CC rate >120/min may be beneficial. The optimal neonatal CC depth is unknown, but factors influencing depth and consistency include the C:V ratio. Incomplete chest wall recoil can cause less negative intrathoracic pressure between CC and reduced CPR effectiveness. CC should be performed with the two-thumb method over the lower third of the sternum. The optimal dose, route and timing of adrenaline administration remain to be determined.

CONCLUSIONS

Successful CPR requires the delivery of high-quality CC, encompassing optimal (A) C:V ratio (B) rate, (C) depth, (D) chest recoil between CC, (E) technique and (F) adrenaline dosage. More animal studies with high translational value and randomised clinical trials are needed.

Factors modulating effective chest compressions in the neonatal period

The need for chest compressions in the newborn is a rare occurrence. The methods employed for delivery of chest compressions have been poorly researched. Techniques that have been studied include compression:ventilation ratios, thumb versus finger method of delivering compressions, depth of compression, site on chest of compression, synchrony or asynchrony of breaths with compressions, and modalities to improve the compression technique and consistency. Although still in its early days, an evidence-based guideline for chest compressions is beginning to take shape.

Chest compressions for bradycardia or asystole in neonates

When effective ventilation fails to establish a heart rate of greater than 60 bpm, cardiac compressions should be initiated to improve perfusion. The 2-thumb method is the most effective and least fatiguing technique. A ratio of 3 compressions to 1 breath is recommended to provide adequate ventilation, the most common cause of newborn cardiovascular collapse. Interruptions in compressions should be limited to not diminishing the perfusion generated. Oxygen (100%) is recommended during compressions and can be reduced once adequate heart rate and oxygen saturation are achieved. Limited clinical data are available to form newborn cardiac compression recommendations.

A comparison of two-fingers technique and two-thumbs encircling hands technique of chest compression in neonates

OBJECTIVE

To compare the proportion of correct placements (POCP) between 'two-fingers' and 'two-thumbs' techniques of chest compression among neonates of various gestations.

STUDY DESIGN

Two-fingers and two-thumbs spans of 32 adult rescuers were individually compared with the inter-nipple line to sterno-xiphoid junction distance of 39 neonates. 'Correct placement' was defined if two-fingers/two-thumbs span was equal to or less than the inter-nipple line to sterno-xiphoid junction distance. The POCPs was compared between two-fingers and two-thumbs methods of chest compression by the McNemar test among neonates and their various subgroups.

RESULT

There were a total of 1248 comparisons. The POCPs with two-fingers and two-thumbs techniques were 6.7 and 77% in all neonates, 10.6 and 89.5% in full term and 1.2 and 59% in preterm neonates, respectively (P<0.001).

CONCLUSION

Two-thumbs technique achieved higher POCPs and should be preferred over two-fingers technique among neonates.

Optimizing chest compressions during delivery-room resuscitation

There is a paucity of data to support the recommendations for cardiac compressions for the newly born. Techniques, compression to ventilation ratios, hand placement, and depth of compression guidelines are generally based on expert consensus, physiologic plausibility, and data from pediatric and adult models.

2005 American Heart Association (AHA) guidelines for cardiopulmonary resuscitation (CPR) and emergency cardiovascular care (ECC) of pediatric and neonatal patients: pediatric basic life support

This publication presents the 2005 American Heart Association (AHA) guidelines for cardiopulmonary resuscitation (CPR) and emergency cardiovascular care (ECC) of the pediatric patient and the 2005 American Academy of Pediatrics/AHA guidelines for CPR and ECC of the neonate. The guidelines are based on the evidence evaluation from the 2005 International Consensus Conference on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations, hosted by the American Heart Association in Dallas, Texas, January 23-30, 2005. The "2005 AHA Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care" contain recommendations designed to improve survival from sudden cardiac arrest and acute life-threatening cardiopulmonary problems. The evidence evaluation process that was the basis for these guidelines was accomplished in collaboration with the International Liaison Committee on Resuscitation (ILCOR). The ILCOR process is described in more detail in the "International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations." The recommendations in the "2005 AHA Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care" confirm the safety and effectiveness of many approaches, acknowledge that other approaches may not be optimal, and recommend new treatments that have undergone evidence evaluation. These new recommendations do not imply that care involving the use of earlier guidelines is unsafe. In addition, it is important to note that these guidelines will not apply to all rescuers and all victims in all situations. The leader of a resuscitation attempt may need to adapt application of the guidelines to unique circumstances. The following are the major pediatric advanced life support changes in the 2005 guidelines: There is further caution about the use of endotracheal tubes. Laryngeal mask airways are acceptable when used by experienced providers. Cuffed endotracheal tubes may be used in infants (except newborns) and children in in-hospital settings provided that cuff inflation pressure is kept <20 cm H2O. Confirmation of tube placement requires clinical assessment and assessment of exhaled carbon dioxide (CO2); esophageal detector devices may be considered for use in children weighing >20 kg who have a perfusing rhythm. Correct placement must be verified when the tube is inserted, during transport, and whenever the patient is moved. During CPR with an advanced airway in place, rescuers will no longer perform "cycles" of CPR. Instead, the rescuer performing chest compressions will perform them continuously at a rate of 100/minute without pauses for ventilation. The rescuer providing ventilation will deliver 8 to 10 breaths per minute (1 breath approximately every 6-8 seconds). Timing of 1 shock, CPR, and drug administration during pulseless arrest has changed and now is identical to that for advanced cardiac life support. Routine use of high-dose epinephrine is not recommended. Lidocaine is de-emphasized, but it can be used for treatment of ventricular fibrillation/pulseless ventricular tachycardia if amiodarone is not available. Induced hypothermia (32-34 degrees C for 12-24 hours) may be considered if the child remains comatose after resuscitation. Indications for the use of inodilators are mentioned in the postresuscitation section. Termination of resuscitative efforts is discussed. It is noted that intact survival has been reported following prolonged resuscitation and absence of spontaneous circulation despite 2 doses of epinephrine. The following are the major neonatal resuscitation changes in the 2005 guidelines: Supplementary oxygen is recommended whenever positive-pressure ventilation is indicated for resuscitation; free-flow oxygen should be administered to infants who are breathing but have central cyanosis. Although the standard approach to resuscitation is to use 100% oxygen, it is reasonable to begin resuscitation with an oxygen concentration of less than 100% or to start with no supplementary oxygen (ie, start with room air). If the clinician begins resuscitation with room air, it is recommended that supplementary oxygen be available to use if there is no appreciable improvement within 90 seconds after birth. In situations where supplementary oxygen is not readily available, positive-pressure ventilation should be administered with room air. Current recommendations no longer advise routine intrapartum oropharyngeal and nasopharyngeal suctioning for infants born to mothers with meconium staining of amniotic fluid. Endotracheal suctioning for infants who are not vigorous should be performed immediately after birth. A self-inflating bag, a flow-inflating bag, or a T-piece (a valved mechanical device designed to regulate pressure and limit flow) can be used to ventilate a newborn. An increase in heart rate is the primary sign of improved ventilation during resuscitation. Exhaled CO2 detection is the recommended primary technique to confirm correct endotracheal tube placement when a prompt increase in heart rate does not occur after intubation. The recommended intravenous (IV) epinephrine dose is 0.01 to 0.03 mg/kg per dose. Higher IV doses are not recommended, and IV administration is the preferred route. Although access is being obtained, administration of a higher dose (up to 0.1 mg/kg) through the endotracheal tube may be considered. It is possible to identify conditions associated with high mortality and poor outcome in which withholding resuscitative efforts may be considered reasonable, particularly when there has been the opportunity for parental agreement. The following guidelines must be interpreted according to current regional outcomes: When gestation, birth weight, or congenital anomalies are associated with almost certain early death and when unacceptably high morbidity is likely among the rare survivors, resuscitation is not indicated. Examples are provided in the guidelines. In conditions associated with a high rate of survival and acceptable morbidity, resuscitation is nearly always indicated. In conditions associated with uncertain prognosis in which survival is borderline, the morbidity rate is relatively high, and the anticipated burden to the child is high, parental desires concerning initiation of resuscitation should be supported. Infants without signs of life (no heartbeat and no respiratory effort) after 10 minutes of resuscitation show either a high mortality rate or severe neurodevelopmental disability. After 10 minutes of continuous and adequate resuscitative efforts, discontinuation of resuscitation may be justified if there are no signs of life.

Pediatric cardiopulmonary-cerebral resuscitation: an overview and future directions

The evolving understanding of pathophysiologic events during and after pediatric cardiac arrest has not yet resulted in significantly improved outcome. Exciting breakthroughs in basic and applied science laboratories are, however, on the immediate horizon for study in specific subpopulations of cardiac arrest victims. Strategically focusing therapies to specific phases of cardiac arrest and resuscitation and evolving pathophysiologic events offers great promise that critical care interventions will lead the way to more successful cardiopulmonary and cerebral resuscitation in children.

Relative merits of ARC guidelines for ECC

Cardiopulmonary Resuscitation is an important component of the pre-hospital emergency care process. Location of the correct site for application of compression in External Cardiac Compression is crucial if patients are not to be exposed to the risk of iatrogenic injury. The procedures approved by the Australian Resuscitation Council for locating the correct site are described as well as a concern that one of these methods (the caliper method) depends on the relation between patients' sternum length and the palm width of the rescuer. The purpose of this study was to measure palm widths and compare these to sternum lengths to determine the likelihood that using the caliper method would result in pressure being applied over the xiphoid process. Results indicated that, using the most conservative comparison, such pressure would be applied in 97% of instances, if the rescuer strictly adhered to the caliper method for locating the correct site. It is recommended that the caliper method be removed as an approved procedure.

Two-thumb vs. two-finger chest compression in an infant model of prolonged cardiopulmonary resuscitation

OBJECTIVE

Previous experiments in the authors' swine lab have shown that cardiopulmonary resuscitation (CPR) using two-thumb chest compression with a thoracic squeeze (TT) produces higher blood and perfusion pressures when compared with the American Heart Association (AHA)-recommended two-finger (TF) technique. Previous studies were of short duration (1-2 minutes). The hypothesis was that TT would be superior to TF during prolonged CPR in an infant model.

METHODS

This was a prospective, randomized crossover experiment in a laboratory setting. Twenty-one AHA-certified rescuers performed basic CPR for two 10-minute periods, one with TT and the other with TF. Trials were separated by 2-14 days, and the order was randomly assigned. The experimental circuit consisted of a modified manikin with a fixed-volume arterial system attached to a neonatal monitor via an arterial pressure transducer. The arterial circuit was composed of a 50-mL bag of normal saline solution (air removed) attached to the manikin chest plate and connected to the transducer with a 20-gauge intravenous catheter and tubing. Rescuers were blinded to the arterial pressure tracing. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were recorded in mm Hg, and pulse pressures (PPs) were calculated. Data were analyzed with two-way repeated-measures analysis of variance. Sphericity assumed modeling, with Greenhouse-Geisser and Huynh-Feldt adjustments, was applied.

RESULTS

Marginal means for TT SBP (68.9), DBP (17.6), MAP (35.3), and PP (51.4) were higher than for TF SBP (44.8), DBP (12.5), MAP (23.3), and PP (32.2). All four pressures were significantly different between the two techniques (p< or =0.001).

CONCLUSION

In this infant CPR model, TT chest compression produced higher MAP, SBP, DBP, and PP when compared with TF chest compression during a clinically relevant duration of prolonged CPR.

Part 9: pediatric basic life support. European Resuscitation Council

The epidemiology and outcome of pediatric cardiopulmonary arrest and the priorities, techniques, and sequence of pediatric resuscitation assessments and intervention differ from those of adults. Current guidelines have been updated after extensive multinational evidence-based review and discussion over several years. Areas of controversy in current guidelines and recommendations made by consensus are detailed. A large degree of uniformity exists in the current guidelines advocated by the AHA, Council on Latin American Resuscitation, Heart and Stroke Foundation of Canada, European Resuscitation Council, Australian Resuscitation Council, and Resuscitation Council of Southern Africa. Differences are currently based on local and regional preferences, training networks, and customs rather than scientific controversy. Unresolved issues with potential for future universal application are highlighted.

Neonatal cardiopulmonary resuscitation: the good news and the bad

Many health care professionals all over the world have been taught neonatal cardiopulmonary resuscitation (CPR) using the neonatal CPR course based upon the work of Bloom and Cropley. The purpose of this article is to provide a retrospective review of the development of some of the neonatal CPR techniques, to discuss current techniques and to complement the dedication of this issue to Dr. Ronald Brown and Catherine Copley, MN, RN.

A randomized, controlled trial of two-thumb vs two-finger chest compression in a swine infant model of cardiac arrest [see comment]

BACKGROUND

The American Heart Association (AHA) currently recommends two-finger (TF) chest compression for infants. A previous study demonstrated that two-thumb (TT) with lateral chest wall compression provided significantly higher arterial pressures than did the TF method. Limitations of that study included the lack of an asphyxial model and non-standardized compression forces.

OBJECTIVE

To test the hypothesis that TT chest compression generates higher arterial pressures than does the TF method, using an asphyxial model. Also, by standardizing sternal compression force (SCF), the authors sought to show that the increased pressures are the result of thoracic compression.

METHOD

The study was a randomized, crossover trial in immature swine weighing 10 kg. Each swine was sedated, anesthetized, paralyzed, intubated, and mechanically ventilated on room air. A femoral arterial catheter was placed. Cardiac arrest was induced by asphyxiation and verified by ECG and pressure tracings. Eleven AHA-certified basic rescuers each randomly performed four 1-minute trials of external chest compressions. Each of the two CPR techniques was performed, with and without feedback of SCF. Compression forces were measured using the Uniforce Sensor System (Force Imaging Technology, Inc., Chicago, IL). During the feedback mode, the rescuers were instructed to maintain sternal pressures at 20-25 psi. During the nonfeedback mode, the rescuers were blinded to the force transducer. All compressions were analyzed for systolic blood pressure (SBP), diastolic blood pressure (DBP), and SCF. Data were analyzed using repeated-measures analysis of variance (RMANOVA) and Tukey multiple comparisons (alpha = 0.05).

RESULTS

A total of 2,297 compressions were analyzed. The TT method produced significantly higher SBPs both with (25% increase) and without (57% increase) feedback when compared with the TF. The DBPs were not significantly different. The SCFs were also significantly higher in the two groups with feedback. The SCFs in the TF groups did not reach the standardized value of 20 psi, whereas in the TT groups, both were in the range of 20-25 psi.

CONCLUSION

The TT method produced significantly higher SBPs. The authors were unable to demonstrate that the increased SBPs were secondary to the thoracic compression component because the rescuers did not reach the predetermined SCF in the TF groups. In this swine model of infant CPR, TT chest compression is an easier and more effective method.

Two-thumb versus two-finger chest compression during CRP in a swine infant model of cardiac arrest

STUDY OBJECTIVE

To test the hypothesis that two-thumb chest compression generates higher arterial and coronary perfusion pressures than the current American Heart Association-approved two-finger method.

DESIGN

Randomized, crossover experimental trial.

SETTING AND PARTICIPANTS

Animal laboratory experiment with seven swine of either sex weighing 9.4 kg (SD, 0.8 kg), representing infants less than 1 year old.

INTERVENTIONS

Animals were sedated with IM ketamine/xylazine, intubated with a 6.0 Hi-Lo endotracheal tube, anesthetized with alpha-chloralose, and paralyzed with pancuronium. ECG was monitored continuously. Left femoral arterial and Swan-Ganz catheters were placed. Cardiac arrest was induced with an IV bolus of KCl and verified by ECG and pressure tracings. Five American Heart Association-certified basic rescuers were randomly assigned to perform external chest compressions for one minute by either the currently recommended two-finger method or the two-thumb and thorax-squeeze method. After all five completed their first trial, rescuers crossed over to the other method for a second minute of compressions. Ventilation was performed with a bag-valve device, and no drugs were given during CPR. After three complete cycles, the fourth through sixth cycles of compressions were recorded. Every compression was analyzed for arterial systolic, diastolic, mean, and coronary perfusion pressures. One thousand fifty compressions were analyzed with repeated-measures analysis of variance and Scheffé multiple comparisons.

RESULTS

Systolic blood pressure, diastolic blood pressure, mean arterial pressure, and coronary perfusion pressure were all significantly higher (P < .001) with the two-thumb thoracic squeeze technique: systolic blood pressure, 59.4 versus 41.6 mm Hg; diastolic blood pressure, 21.8 versus 18.5 mm Hg; mean arterial pressure, 34.2 versus 26.1 mm Hg; and coronary perfusion pressure, 15.1 versus 12.2 mm Hg.

CONCLUSION

The two-thumb method of chest compression generates significantly higher arterial and coronary perfusion pressures than the two-finger method in this infant model of cardiac arrest.