Introduction of precordial Doppler ultrasound to confirm correct peripheral venous access during general anesthesia in children: A preliminary study

Optimal dose of normal saline for confirming correct peripheral venous access with precordial Doppler ultrasonography in children

Precordial Doppler ultrasound technology can be utilized to confirm correct peripheral intravenous vascular (PIV) access in children during surgery. This study aimed to determine the minimally required dose of normal saline (NS) for confirming correct PIV access. Healthy children were randomly allocated to receive a 0.1 mL/kg, 0.3 mL/kg, or 0.5 mL/kg dose of NS injected via PIV access. Two independent raters judged the change in the recorded precordial Doppler sound test (S-test) before and after NS injection. Typically, rapid injection of NS increased the pitch of the heartbeat as the injection volume increased. Changes in blood flow velocity test (V-test) results were evaluated using a cut-off value of 1 cm/s. Both in the S- and V-tests, the detection rate of correct PIV access was lower with 0.1 mL/kg NS than with 0.3 mL/kg or 0.5 mL/kg. Logistic regression analysis showed that the positive results in both the S- and V-tests were significantly decreased with a 0.1 mL/kg NS; no significant difference was observed with a 0.3 mL/kg NS (reference dose: 0.5 mL/kg). These results suggest 0.3 mL/kg is the minimally required dose of NS for confirming correct PIV access. This study is registered with the University Hospital Medical Information Network (UMIN000041330).

Precordial Doppler to assess vascular access in children: A preliminary report

BACKGROUND

Delayed identification and dysfunction of peripheral intravenous (PIV) infiltration can lead to serious injury in children. This preliminary study aimed to describe the application of precordial Doppler ultrasound to detect and confirm the correct PIV access in children with congenital heart disease (CHD).

METHODS

This study was conducted on children (<18 years) diagnosed with CHD and admitted to the pediatric intensive care unit (PICU) of a single center after cardiac surgery or cardiac catheterization between February 2020 and May 2021. Three raters judged the precordial Doppler sound change (S test) after injection of 0.5 mL/kg of normal saline (NS) through the PIV access. Blood-flow velocities before and after the NS injection were recorded and the accuracy of detecting PIV catheter infiltration and dysfunction was analyzed (V test).

RESULTS

The overall incidence of PIV infiltration and dysfunction was in 3 out of 103 patients (2.9%). The sensitivity, specificity, positive and negative likelihood ratios, and area under the receiver operating characteristic curve were 3 out of 3 [100%, 95% confidence interval (CI): 29.2-100], 86 out of 100 (86%, 95% CI: 77.6%-92.1), 7.1, 0.0, and 0.93, respectively, in the S test and they were 2 out of 3 (66.7%, 95% CI: 9.4%-99.2), 94 out of 100 (94.0%, 95% CI: 87.4%-7.8%), 11.1, 0.36, and 0.80, respectively in the V test.

CONCLUSIONS

Precordial Doppler ultrasound was a feasible and accurate technique for confirming correct PIV access in children with CHD; however, a larger, prospective investigation is necessary to examine its diagnostic accuracy.

Optimal probe position for precordial Doppler ultrasound in children

BACKGROUND

Precordial Doppler ultrasound technology can be used to confirm correct peripheral intravenous access in children. Changes in precordial Doppler sound from the baseline after injecting normal saline are detected using a correct peripheral intravenous access. However, the location of the precordial Doppler probe has been inconsistent in previous studies. Our study aimed to determine whether the right or left parasternal border is the optimal location for precordial Doppler probe placement.

METHODS

This single-center, prospective interventional study was conducted between July 2021 and January 2022 and included children aged 1-6 years. The Doppler probe was placed under general anesthesia at the most audible site on the right and left parasternal borders of patients. Baseline heartbeat was recorded by the Doppler for 10 s on the right and left parasternal borders. After randomizing the order of the recorded data, two blinded raters separately listened to the data and decided the audibility of the sounds.

RESULTS

A total of 77 patients were enrolled in the study. The proportion of the audible baseline heartbeat was significantly higher on the left parasternal borders than on the right by both rater 1 (96.1%, 22.1%, p < 0.001) and rater 2 (96.1%, 27.3%, p < 0.001). Regarding inter-rater reproducibility, Cohen's kappa statistics for the left and right parasternal borders were significant (0.65 and 0.79, both p < 0.001).

CONCLUSIONS

The baseline heartbeat was more audible on the left parasternal border than on the right parasternal border with acceptably high interrater reproducibility. This is inconsistent with the interpretations of previous reports.