Reducing unnecessary diagnostic phlebotomy in intensive care: a prospective quality improvement intervention

Intensive care unit (ICU) patients are at high risk of anemia, and phlebotomy is a potentially modifiable source of blood loss. Our objective was to quantify daily phlebotomy volume for ICU patients, including blood discarded as waste during vascular access, and evaluate the impact of phlebotomy volume on patient outcomes.

Thomas Bodley , 1,2 Olga Levi,3,4 Maverick Chan,3,5

Lisa K Hicks1,3,5

Editor: Raffaele Serra, University Magna Graecia of Catanzaro, ITALY

Received: September 24, 2020

Abstract

Accepted: November 25, 2020

Methods

Published: January 13, 2021

Background Critically ill patients receive frequent routine and recurring blood tests, some of which are unnecessary.

Aim To reduce unnecessary routine phlebotomy in a 30-bed tertiary medical-surgical intensive care unit (ICU) in Toronto, Ontario.

Methods This prospective quality improvement study included a 7-month preintervention baseline, 5-month intervention and 11-month postintervention period.

Copyright: © 2021 Bodley et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Change strategies included education, ICU rounds checklists, electronic order set modifications, an electronic test add-on tool and audit and feedback. The primary outcome was mean volume of blood collected per patient-day. Secondary outcomes included the number blood tubes used and red cell transfusions. Balancing measures included the timing and types of blood tests, ICU length of stay and mortality. Outcomes were evaluated using process control charts and segmented regression.

Data Availability Statement: All relevant data are within the manuscript and its Supporting information files. Please note that age and length of stay have been removed from the logistic regression data set to comply with the studies REB requirements. The St. Michael’s Hospital Institutional Research Ethics Board (contact via 1416-864-6060 Ext. 42557) is available for contact if further clarifications are required.

Funding: LKH (Lisa K. Hicks) is supported by the Innovation Fund through the 1) Ontario Medical

Results Patient demographics did not differ between time periods; total number of patients: 2096, median age: 61 years, 60% male. Mean phlebotomy volume±SD decreased from 41.1±4.0 to 34.1±4.7 mL/patient-day. Special cause variation was met at 13 weeks. Segmental regression demonstrated an immediate postintervention decrease of 6.6 mL/patient-day (95% CI 1.8 to 11.4

This was a retrospective observational cohort study between September 2014 and August 2015 at a tertiary care academic medical-surgical ICU. A prospective audit of phlebotomy practices in March 2018 was used to estimate blood waste during vascular access. Multivariable logistic regression was used to evaluate phlebotomy volume as a predictor of ICU nadir hemoglobin < 80 g/L, and red blood cell transfusion.

What Is Already Known On This Topic

⇒ Repetitive phlebotomy contributes to intensive care unit (ICU) acquired anaemia and red blood cell transfusion.

Results

What This Study Adds

⇒ Multimodal interventions focusing on ICU test ordering behaviour can result in a durable reduction in ICU phlebotomy and blood test tube consumption by reducing clinician identified unnecessary testing.

HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY

There were 428 index ICU admissions, median age 64.4 yr, 41% female. Forty-four patients (10%) with major bleeding events were excluded. Mean bedside waste per blood draw (144 draws) was: 3.9 mL from arterial lines, 5.5 mL central venous lines, and 6.3 mL from peripherally inserted central catheters. Mean phlebotomy volume per patient day was 48.1 ± 22.2 mL; 33.1 ± 15.0 mL received by the lab and 15.0 ± 8.1 mL discarded as bedside waste. Multivariable regression, including age, sex, admission hemoglobin, sequential organ failure assessment score, and ICU length of stay, showed total daily phlebotomy volume was predictive of hemoglobin <80 g/L (p = 0.002), red blood cell transfusion (p<0.001), and inpatient mortality (p = 0.002). For every 5 mL increase in average daily phlebotomy the odds ratio for nadir hemoglobin <80 g/L was 1.18 (95% CI 1.07–1.31) and for red blood cell transfusion was 1.17 (95% CI 1.07–1.28).

⇒ This study identifies change strategies that can be adapted and implemented in other care environments to reduce blood waste, conserve blood testing tubes and reduce blood collections. Future efforts are needed to translate these results to other care environments

It’s time to Pause the Draw!

A Unity Choosing Wisely Initiative

Repetitive blood draws in the ICU add-up quickly and can harm patients. There is also a shortage of phlebotomy tubes and reagents.

At morning rounds ask if all blood tests are essential

• Avoid open-ended orders for bloodwork

• Use the demedialization orderset when appropriate Whenever possible, add-on tests to exising blood draws

Avoid or reduce high frequency repetitive testing wherever possible.

Pause Thedraw

It’s time to

Pause the Draw!

• At morning rounds ask if all blood tests are essential

• Avoid open-ended orders for blood work

• Use the demedicalization orderset when appropriate

• Whenever possible, add-on tests to exising blood draws

Pause Thedraw

Repetitive blood testing at St. Michael’s

How to add on tests to already drawn blood sample (ex: Alb,Trop, Mg). Ensure previous sample with appropriate tube colour is sent within specified time frame (see SMH Laboratory Test Catalogue http://www.stmichaelshospital.com/programs/labs/tests/)

The project began by trying to understand the source of the problem. Through staff interviews, diagramming exercises, and extensive literature review several interventions were developed for the project. Many change strategies involved working closely with Laboratory Medicine to restructure the lab test ordering system and interface to ensure clinicians were considering the amount of bloodwork they were ordering. Other change strategies involved developing educational and infographic material for staff in the MSICU to raise awareness of this issue. I developed the Pause the Draw campaign to tie all of our interventions together into a recognizable initiative for staff. In addition, I worked closely with the data department to collect and analyze different lab metrics to track the success of our interventions and provide valuable feedback information to staff each week on their progress.