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

Diagnostic test accuracy for cessation of circulation during death determination: a systematic review

PURPOSE

To synthesize the available evidence comparing noninvasive methods of measuring the cessation of circulation in patients who are potential organ donors undergoing death determination by circulatory criteria (DCC) with the current accepted standard of invasive arterial blood pressure (IAP) monitoring.

SOURCE

We searched (from inception until 27 April 2021) MEDLINE, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials. We screened citations and manuscripts independently and in duplicate for eligible studies that compared noninvasive methodologies assessing circulation in patients who were monitored around a period of cessation of circulation. We performed risk of bias assessment, data abstraction, and quality assessment using Grading of Recommendations, Assessment, Development, and Evaluation in duplicate and independently. We presented findings narratively.

PRINCIPAL FINDINGS

We included 21 eligible studies (N = 1,177 patients). Meta-analysis was not possible because of study heterogeneity. We identified low quality evidence from four indirect studies (n = 89) showing pulse palpation is less sensitive and specific than IAP (reported sensitivity range, 0.76-0.90; specificity, 0.41-0.79). Isoelectric electrocardiogram (ECG) had excellent specificity for death (two studies; 0% [0/510]), but likely increases the average time to death determination (moderate quality evidence). We are uncertain whether point-of-care ultrasound (POCUS) pulse check, cerebral near-infrared spectroscopy (NIRS), or POCUS cardiac motion assessment are accurate tests for the determination of circulatory cessation (very low-quality evidence).

CONCLUSION

There is insufficient evidence that ECG, POCUS pulse check, cerebral NIRS, or POCUS cardiac motion assessment are superior or equivalent to IAP for DCC in the setting of organ donation. Isoelectric ECG is specific but can increase the time needed to determine death. Point-of-care ultrasound techniques are emerging therapies with promising initial data but are limited by indirectness and imprecision.

STUDY REGISTRATION

PROSPERO (CRD42021258936); first submitted 16 June 2021.

Femoral Arterial Doppler Use During Active Cardiopulmonary Resuscitation

STUDY OBJECTIVE

This study explored femoral arterial Doppler during active cardiopulmonary resuscitation (CPR) to identify and characterize the resumptions of cardiac activity without stopping CPR.

METHODS

This was a proof-of-concept study exploring arterial Doppler during cardiac arrest. Patients in cardiac arrest undergoing active CPR were prospectively enrolled. Arterial Doppler of the common femoral artery was recorded during CPR and during pauses in CPR. CPR-induced arterial tracings and native cardiac-induced tracings were analyzed for rate and peak systolic velocity. Cardiac activity on echocardiogram during pause in CPR was classified as "absent," "disorganized," or "organized." Descriptive data and survival are presented as mean and 95% confidence intervals (CI), as well as sensitivity and specificity of Doppler during active CPR in detecting native cardiac pulsations.

RESULTS

Sixteen patients with 48 paired Doppler recordings during active CPR, pause in CPR, and associated echocardiogram were enrolled. Native cardiac-induced tracings were visible during 39.6% of pauses in CPR (19 of 48) and during 18.8% of the periods of active CPR (9 of 48). Arterial pulsations were more frequently visualized with organized contractions by echocardiogram (10 of 14, 71%) than disorganized contractions (9 of 22, 41%). Arterial Doppler was 100% specific and 50% sensitive in detecting organized cardiac activity during active CPR. Patients with visible native cardiac pulsations during active CPR demonstrated 0% mortality compared with 67% mortality without visible arterial pulsations.

CONCLUSION

Arterial Doppler tracings may identify the resumption of native cardiac activity during active CPR; however, more research is needed.

Manual Palpation vs. Femoral Arterial Doppler Ultrasound for Comparison of Pulse Check Time During Cardiopulmonary Resuscitation in the Emergency Department: A Pilot Study

BACKGROUND

Manual palpation (MP) is frequently employed for pulse checks, but studies have shown that trained medical personnel have difficulty accurately identifying pulselessness or return of spontaneous circulation (ROSC) using MP. Any delays in identifying pulselessness can lead to significant delays in starting or resuming high-quality chest compressions.

OBJECTIVES

This study explored whether femoral arterial Doppler ultrasound (FADU) decreases pulse check duration during cardiopulmonary resuscitation (CPR) compared with MP among patients in the emergency department (ED) receiving CPR directed by emergency medicine physicians who had received minimal additional didactic ultrasound training.

METHODS

We performed a prospective observational cohort study from October 2018 to May 2019 at an urban community ED. Using convenience sampling, we enrolled patients arriving at our ED or who decompensated during their ED stay and received CPR. For continuous data, median (interquartile range [IQR]) were calculated, and medians were compared using Kruskal-Wallis test.

RESULTS

Fifty-two eligible patients were enrolled and 135 pulse checks via MP and 35 via FADU were recorded. MP observations had a median (IQR) of 11.00 (7.36-15.48) s, whereas FADU had a median (IQR) of 8.98 (5.45-13.85) s. There was a difference between the two medians of 2.02 s (p = 0.05).

CONCLUSIONS

In this study, the use of FADU was superior to MP in achieving shorter pulse check times. Further research is needed to confirm the accuracy of FADU for identifying ROSC as well as to determine whether FADU can improve clinical outcomes.

The POCUS pulse check: A randomized controlled crossover study comparing pulse detection by palpation versus by point-of-care ultrasound

BACKGROUND

Manual pulse checks (MP) are an unreliable skill even in the hands of healthcare providers (HCPs). In the context of cardiac arrest, this may translate into inappropriate chest compressions when a pulse is present, or conversely omitting chest compressions when one is absent. To date, no study has assessed the use of B-mode ultrasound (US) for the detection of a carotid pulse. The primary objective of this study was to assess the time required to detect a carotid pulse in live subjects using US compared to the traditional palpation method.

METHODS

We conducted a prospective randomized controlled crossover non-inferiority trial. HCPs attended a 15 minute focused US workshop on identification of the carotid pulse. Both pulse check methods were timed for each participant on two different subjects in random order. The primary outcome was time to carotid pulse detection in seconds (s). Secondary outcomes included confidence levels of pulse detection measured on a 100 mm visual analog scale (VAS) and rates of prolonged pulse checks (> 5 s or >10 s). The study was powered to determine whether US pulse checks were not slower than MP by greater than two seconds. The results are presented as the difference in means with a 90% two-sided confidence interval (CI).

RESULTS

111 participants completed the study. Mean pulse detection times were 4.22 s (SD 3.26) by US compared to 4.71 s (SD 6.45) by MP with a mean difference in times of -0.49 s (90% CI: -1.77 to 0.39). There were no significant differences between US and MP in the rates of prolonged pulse checks of greater than 5 s (23% vs 19%, p = 0.45) or 10 s (9% vs 8%, p = 0.81). First attempt at detection of pulse checks was more successful in the US group (99.1% vs 85.6%, p = 0.0001). Prior to training, participants reported higher confidence using MP compared to US; 68 (IQR 48-83) vs 15 (IQR 8-42) mm (p < 0.001). Following the study, participants reported higher confidence levels using US than MP; 91 (IQR 82-97) vs 83 (IQR 72-94) mm (p < 0.001).

CONCLUSIONS

Carotid pulse detection in live subjects was not slower using US as compared to palpation, and demonstrated higher first attempt success rate and less variability in measurement times. A brief teaching session was sufficient to improve confidence of carotid pulse identification even in those with no previous US training. The preliminary results from this study provide the groundwork for larger studies to evaluate this pulse check method for patients in cardiac arrest.

The reliability of carotid ultrasound in determining the return of pulsatile flow: A pilot study

Manual palpation of pulses is unreliable in detecting pulsatile flow in human participants, complicating the assessment of return of spontaneous circulation after cardiac arrest. Ultrasound may offer an alternative. This study's objective was to investigate whether return of pulsatile flow in humans can be reliably assessed by common carotid artery ultrasound. We conducted a single-blinded randomised study of common carotid artery ultrasound using 20 cardiopulmonary bypass patients to model the return of pulsatile flow. Synchronised time-stamped videos of radial artery invasive blood pressure and 10 two-dimensional or 10 colour Doppler ultrasounds were recorded. Three independent reviewers recorded the timestamp where they considered pulsatile flow was first visible on ultrasound. Ultrasound times were compared to the onset of arterial line pulsatile flow and reliability assessed by intraclass correlation coefficient. The median difference between radial artery and ultrasound flow time (interquartile range (range)) was 24 seconds (5-40 (0-93)) for two-dimensional and 5 seconds (2-17 (-28 to 188)) for colour Doppler. The intraclass correlation coefficient for two-dimensional ultrasound was 0.86 (95%CI 0.63-0.96) and 0.32 (95%CI -0.01 to 0.71) for colour Doppler. The median (interquartile range (range)) mean arterial pressure where ultrasound flow occurred for two-dimensional ultrasound was 62 mmHg (49-74 (33-82)) and 56 mmHg (52-73 (43-83)) for colour Doppler. In our pilot study, two-dimensional ultrasound was reliable in detecting the return of pulsatile flow. Colour Doppler detected pulsatile flow earlier and at lower mean arterial pressure but was not reliable, although a larger study is needed to determine colour Doppler's utility.