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Handheld Doppler to improve pulse checks during resuscitation of putative pulseless electrical activity arrest.

The difficulty of determining pulselessness via manual palpation in simulated cardiopulmonary resuscitation (CPR) has been well-documented in the literature. Prior studies have suggested that trained medical personnel demonstrate a specificity for the manual diagnoses of pulselessness of only 55%.1 Other research has confirmed the poor diagnostic accuracy of manual pulse checks in a wide spectrum of test subjects - from non-medical personnel to critical care physicians.1–4 These data, along with accumulating evidence for the importance of early, high quality chest compression to improve outcomes from out-of-hospital cardiac arrest, have led the American Heart Association to eliminate pulse checks from their algorithm for bystander CPR. a 
 
In this context, the Advanced Cardiac Life Support (ACLS) algorithm for the treatment of Pulseless Electrical Activity (PEA) arrest presents an interesting dilemma, as the very diagnosis of the PEA condition is predicated, by definition, on the finding of pulselessness. Although unnecessary chest compressions during bystander CPR are considered a relatively benign intervention, the failure to promptly diagnose the return of spontaneous circulation during in-hospital PEA Arrest may delay the institution of more targeted and appropriate care modalities. Ambiguity about the presence of spontaneous circulation during resuscitation is among many factors that contributes to the challenging task of “running a code.” 
 
Therefore, in order to assess possibilities for improving the detection of the return of spontaneous circulation during in-hospital resuscitation, we conducted a prospective case series (N=8) during which handheld Doppler pulse checks were performed in parallel with standard ACLS procedures during resuscitation of adults with putative PEA arrest or on whom electrocardiogram pads had not yet been placed in an academic tertiary care hospital. The outcomes of interest were: 1) To measure the incidence of Doppler-positive-palpation-negative pulse in patients undergoing resuscitation for putative PEA arrest, and 2) To measure blood pressure in discordant cases of Doppler-positive-palpation-negative putative PEA arrest. 
 
This prospective study was approved by the Yale Human Investigation Committee, including a waiver of informed consent. Investigators applied a portable Doppler (Dopplex Pocket Doppler D900 Vascular Ultrasound with 8MHz probe, Huntleigh, United Kingdom) to an available femoral artery during inhospital resuscitation attempts for putative PEA arrest or in situations of unknown cardiac rhythm prior to electrocardiogram lead placement. The Dopplex D900 with associated probes has been deemed by the Food and Drug Administration to be substantially equivalent to other portable ultrasound devices routinely used for blood flow monitoring. While this technology has been in existence for several decades, the sensitivity and specificity of such devices for detecting pulsatile flow during CPR remain unknown. 
 
For inclusion in the study, a putative PEA rhythm was defined as an organized rhythm in the absence of a manual pulse, excluding ventricular tachycardia and ventricular fibrillation.b To be included in the case series, subjects also had to meet the following criteria: 1) age > 18 years, 2) ongoing CPR, and 3) availability of a peripheral site for application of a Doppler probe. For included subjects, audible Doppler pulse checks occurred in addition to standard ACLS procedures simultaneously with manual pulse checks. The site of manual pulse checks was not dictated by the research protocol. Doppler pulse checks occurred at an available femoral location that was not being used for the manual pulse check. In the event of a discordant finding of Doppler-positive-palpation-negative pulse, a repeat pulse check and blood pressure measurement were requested, with all management decisions left to the discretion of the code-runner. The cases represent a convenience sample of codes that occurred during times that a study investigator was available to respond. Codes occurred at a tertiary care hospital at which approximately 24 codes are called per month overhead, of which approximately 15% are true cardiac arrests.