Anest. intenziv. Med. 2012;23(4):197-202

Assessment of variability of normal and pathological microcirculation by SDFIntensive Care Medicine - Original Paper

Krbúšik Ján, Suk Pavel, Hruda Jan, Zvoníček Václav, Pavlík Martin, Šrámek Vladimír, Čundrle Ivan jr.^*

Anesteziologicko resuscitační klinika, Fakultní nemocnice u sv. Anny v Brně Lékařská fakulta Masarykovy univerzity

Introduction:
One of the options for microcirculation monitoring is sidestream dark field imaging (SDF). The goal of this study was to assess the interobserver and intraobserver variability of SDF during an experiment simulating rupture of the abdominal aorta on a porcine model.

Methods:
The interobserver variability was evaluated sublingually and in the ileostoma. Two investigators (skilled and novice) analyzed the recordings blindly. The interobserver variability was evaluated using the Bland Altman analysis. The results are shown as percentage bias and limits of agreement. Bias > 15% was considered as significant. The bias was sectionalized in two groups according to normal and pathological parameter values for the two main parameters (TVD, MFI). The intraobserver variability was evaluated using the coefficient of variability.

Results:
640 video recordings were analyzed for interobserver and 30 video recordings for intraobserver variability. Sublingually the bias was -5% (-20%; 12%) for TVD and -3% (-22%; 15%) for MFI. In the ileostoma the bias was 7% (-49%; 62%) for TVD and 7% (-31%; 45%) for MFI. The bias for TVD decreased when the value dropped to pathological values both sublingually and in the ileostoma but the limits of agreement were rising. The bias of MFI increased when the value dropped to pathological values and decreased when the value rose. The limits of agreement followed the same tendency. The coefficients of variability were low for both observers (CV < 10%).

Conclusion:
The intraobserver variability was minimal for both investigators. The interobserver variability was small (bias < 15%). The limits of agreement were wide for density parameters, overall for microcirculation in the ileostoma and for pathological parameter values (hyperdynamic flow was an exception).

Keywords: microcirculation; sidestream dark field imagining; interobserver variability; intraobserver variability

Received: May 16, 2012; Accepted: July 25, 2012; Published: August 1, 2012  Show citation