Time is muscle: measuring workflow and procedure duration in the catheterization laboratory
Authors: Vijfvinkel T S , Nikookar B , Constandse J , Hendriks B H W , Van Der Elst M , Van Den Dobbelsteen J J 
Published: November 2023

Abstract

Introduction
Cardiac catheterization laboratories (cath labs) represent one of the most significant labour- and cost-intensive departments within the hospital. In the coming years, the demand for interventions in cath labs will rise with the increase of the prevalence of cardiovascular diseases. Therefore, optimization of cath lab efficiency is a growing necessity. Previous studies have highlighted the importance of efficiency improvements in hospitals. For example, reliable estimations of procedure duration and real-time progress indications have proven to be critical conditions to enhance efficiency in the operating theatre. Similar developments could also benefit cath labs, as workflow monitoring and management present opportunities to increase both efficiency and patient safety.

Purpose
The aim of this study is to measure and quantify the workflow within a cath lab, consisting of all clinical activities and the associated daily routine. Furthermore, the impact of process-, patient-, and staff-related parameters on the workflow will be assessed.

Methods
During an observational study, diagnostic cardiac angiograms (CAGs) were recorded with 5 video cameras in the cath lab. Subsequently, clinically-relevant key points were manually annotated by two independent observers based on the collected video images. These predefined key points were established by consensus among cardiologists. The annotations were converted to represent durations of specific procedure phases. Clinical information of the included procedures was collected from the electronic patient files. Multivariate regression analysis was used to test for correlations between clinical parameters and phase durations.

Results
A total of 297 diagnostic CAGs were included in this study. The mean total duration of a CAG was 46,67 minutes (SD ± 17,17). Of all the phases, the preparation phase had the longest duration, with an average of 20,42 minutes (SD ± 9,90). The most contributing factor to the total duration of a procedure was the use of one or more additional catheters besides the standard equipment (Spearman’s ρ=0,42). Furthermore, the cardiologist performing the CAG significantly influenced the phases involving the actual clinical activities, with mean durations ranging from 35,86 minutes to 63,47 minutes. Patient characteristics such as age, BMI and gender did not cause the phase durations to deviate significantly.

Conclusions
This study measured cath lab workflow based on key events which were visible during CAGs. The impact of process-, patient- and staff-related factors on the workflow was determined and quantified. This will enable hospital staff and management to understand their current workflow and improve accordingly. Moreover, a detailed understanding of the workflow provides ways to assess workload and guidance towards optimal working conditions. Ultimately, these insights support the development of an algorithm capable of automated continuous workflow monitoring.