Standardization and quality control of the introduction of a noninvasive cardiac output monitor for pregnancy measurements in a low- and middle-income country.

Abstract

Introduction: There is increasing awareness of the role of the maternal cardiovascular system in complicated pregnancies. Despite the high disease burden, noninvasive cardiac output monitors have not been used extensively in low- and middle-income countries. The aim of this study was to evaluate the quality control of the use of the ultrasonic cardiac output monitor (USCOM) 1A® in a LMIC.

Material and methods: This was a quality assessment study of the introduction of the USCOM 1A® to measure maternal hemodynamic indices. Inter-observer agreement was assessed across all four study sites by intraclass correlation coefficient. Quality control was assessed using pre-defined acceptability criteria, rated by 2 independent scorers.

Results: On average, nurses or midwives needed to obtain 30.4 (range 24-36) Doppler waveform recordings to be deemed competent to undertake USCOM 1A® measurements. There was very good inter-observer agreement across all 4 sites (intraclass correlation coefficient 0.86-0.93, all p < 0.001). A total of 138 images were randomly selected for quality review. Overall, 79 (89.8%) images were considered acceptable by both scorers; 4 (6.9%) were considered unacceptable by both scorers; and there was disagreement in 5 (5.7%) cases. Overall agreement was 94.3%. Agreement as assessed by Fleiss' kappa, was moderate (0.585 [95% CI 0.376-0.794], p < 0.001).

Conclusions: Using a robust learning package and clearly defined image criteria, a novel cardiac-output monitor can be successfully introduced into low- and middle-income countries, in the context of research. Ongoing quality control measures are imperative to maintain the integrity of planned future studies using USCOM 1A®.