CO₂ Business Case in Hospitals: Minimum KPIs and Operational Scope to Reduce AKI/CIN Without Endless Pilot Projects
A well-structured CO₂ business case transforms the adoption of contrast-sparing/Zero Contrast angiography from a “good idea” into a manageable decision for Hospital Management. It requires an essential set of clinical and economic KPIs, a clearly defined initial scope (infradiaphragmatic procedures and risk profiles), and a foundation of standardization and digital traceability that makes HTA (Health Technology Assessment) reproducible and scalable. The goal is to reduce AKI/CIN (Acute Kidney Injury/Contrast-Induced Nephropathy), length of stay and related costs, while avoiding “pilot projects” that never reach a conclusion.
Why CO₂ projects stall: the problem is not the technology, but the measurement
In Italian and European hospital practice, CO₂ is often evaluated using inconsistent indicators, such as “less iodine used,” “perceived safety” and “variable image quality.” This makes every discussion within a Technology Committee or HTA process open to interpretation, because there are no denominators, shared clinical definitions or comparable data across teams and operating rooms. Furthermore, without standardized protocols and traceable injection parameters, it is difficult to distinguish the effect of the strategy (CO₂-first/CO₂-only) from the effect of the individual operator.
A business case works when it defines: who to include (patients), where to begin (procedures), what to measure (minimum KPIs) and how to make the data auditable (digital traceability, workflow and governance).
CO₂ business case: minimum clinical and economic KPIs (essential set)
To maximize comparability and the ability to reference the results, KPIs should be limited in number, standardized and linked to clinical outcomes and resource consumption. The minimum set below enables a rapid assessment over 12–16 weeks and a scaling decision based on local evidence.
- Incidence of post-procedural AKI (KDIGO definition): proportion of patients with an increase in creatinine within 48–72 hours or reduced urine output, with baseline data collection and scheduled follow-up.
- Incidence of CIN/CA-AKI according to the definition adopted by the center, which should be declared in the HTA: useful for internal comparisons, provided that the definition remains consistent over time and across departments.
- Total volume of iodinated contrast medium per procedure (mL) and “Zero Contrast” rate (proportion of cases performed without iodine): this is the operational output most closely related to clinical practice.
- Dialysis/CRRT related to renal complications (new requirement or escalation): rare but highly impactful, making it essential for Hospital Management and risk management.
- Length of stay (LOS) and 30-day readmissions due to renal or related complications: cost and quality proxies that align with the language of clinical governance.
- Incremental cost per case (consumables, procedure-room time and imaging) and estimated avoided costs (AKI, LOS, dialysis and additional examinations/visits): the minimum structure required for a local cost-outcome model.
- Workflow quality and safety: rate of procedure-related adverse events, conversions to iodine due to inadequate imaging and compliance with the checklist/protocol.
- Traceability of CO₂ injection parameters (present/absent and level of completeness): without this KPI, the reproducibility and defensibility of the HTA are reduced.
Practical note: AKI and LOS are the KPIs most likely to unlock the decision-making process because they combine clinical outcomes and sustainability. Iodine volume and the Zero Contrast rate are process KPIs required to explain why outcomes change.
Where to begin: an “infradiaphragmatic” operational scope and high-risk patient profiles
To avoid endless pilots, the initial scope should offer a high likelihood of measurable clinical benefit and sufficient procedural volumes. In Europe, CO₂ is typically used in vascular procedures below the diaphragm, where the objective is to reduce or eliminate iodine while maintaining image quality appropriate for the clinical task.
Priority procedures (initial set): lower-limb peripheral angiography and endovascular treatments (PAD/CLTI), iliac, femoral, popliteal and tibial procedures, and selected diagnostic and therapeutic assessments in infradiaphragmatic vascular territories. The aim is to select procedures with a reproducible pathway and measurable renal outcomes, avoiding the inclusion of excessively heterogeneous cases within the same phase.
Risk profiles (recommended inclusion criteria for the business case): patients with chronic kidney disease (CKD), diabetes, advanced age, dehydration or previous AKI; patients with a history of reactions to iodinated contrast medium; and patients exposed repeatedly to contrast medium within short periods, for example during diagnostic and therapeutic pathways. Defining operational thresholds, such as eGFR values and CKD stages, makes the protocol auditable and reduces potential disputes.
Governance rule: begin with 1–2 procedure rooms and one “owner” team, while applying identical enrolment criteria and laboratory follow-up requirements. The project can then be extended by cluster, such as additional rooms or shifts, once the KPIs and protocol compliance are stable.
Standardization and digital traceability: the prerequisite for an objective HTA
Hospital Management obtains value when it can attribute an outcome to a controlled process. With CO₂, this means having protocols for patient selection, preparation, injection parameters, imaging synchronization, consumables and the management of conversions to iodine. Digital traceability of the parameters enables audits, comparisons between operators and the creation of datasets that support Clinical Governance.
In this context, automated solutions such as the Angiodroid CO₂ injector are relevant not only for performing the procedure, but also for achieving repeatable standardization and making processes measurable: reducing operator-dependent variability, creating a more controlled workflow and generating data that are more defensible before a Technology Committee.
How to close the decision-making cycle: timelines, thresholds and “stop rules”
An effective business case has a short assessment period and clear decision-making rules. Set up a 12–16-week evaluation using consecutive cohorts with fixed inclusion criteria and compare the results with a homogeneous historical baseline. Defining minimum expected thresholds in advance, such as a reduction in iodine volume per case, an increase in the Zero Contrast rate among patients with CKD, and stable or reduced AKI rates, prevents the project from remaining “under observation” indefinitely.
Stop rules protect both patients and resources: if conversions to iodine increase because of inadequate image quality, if compliance with creatinine follow-up falls below an established threshold, or if safety events emerge as a result of non-compliance with the protocol, training and review should be implemented before extending the project. This approach makes CO₂ a clinical and organizational strategy rather than an experiment.
How to establish a CO₂ business case in 30 days without an endless pilot
Step 1: Define the scope and denominators
Select 1–2 high-volume infradiaphragmatic procedures, such as lower-limb peripheral interventions, and establish renal-risk inclusion criteria based on CKD/eGFR, diabetes and repeated contrast exposure. Define the denominators: number of procedures, number of eligible patients, number of patients included and number completing creatinine follow-up.
Step 2: Establish the minimum KPI set and data plan
Adopt the essential KPI set—KDIGO-defined AKI, iodine volume, Zero Contrast rate, LOS, readmissions, dialysis/CRRT and costs—and define who is responsible for collecting each data point, including the procedure room, laboratory, hospital discharge records and management control. Introduce a clear rule: no case is considered “valid” without a baseline measurement and creatinine assessment at 48–72 hours, or an agreed alternative.
Step 3: Standardize the protocol and traceability
Formalize the checklist and operational protocol, including patient selection, preparation and the management of conversion to iodine. Require digital traceability of procedural parameters and standardize reports for auditing purposes. When introducing an automated CO₂ injector, include initial training and a case-review session after two weeks.
Step 4: Define thresholds and the scaling decision
Pre-approve the thresholds and timeline of 12–16 weeks: targets for reducing iodine use, increasing the proportion of Zero Contrast cases among patients with CKD, avoiding any deterioration in procedural quality and achieving favorable AKI/LOS trends. Schedule a final meeting with Hospital Management and reach a binary decision: extend the program to additional procedure rooms or revise the protocol.
Frequently asked questions
What are the minimum KPIs required to demonstrate that CO₂ reduces AKI/CIN in a hospital?
The minimum KPIs include the incidence of AKI according to the KDIGO definition, the volume of iodinated contrast medium used per procedure and the rate of Zero Contrast cases. LOS, 30-day readmissions and the need for dialysis/CRRT are also essential for Hospital Management. These indicators directly connect clinical outcomes with economic impact.
Which procedures should be selected first for a contrast-sparing CO₂ pathway without extending the pilot unnecessarily?
It is advisable to begin with high-volume infradiaphragmatic vascular procedures that have a reproducible workflow, such as lower-limb peripheral angiography and endovascular treatments. A narrowly defined scope reduces clinical heterogeneity and makes the KPIs easier to interpret. The program can subsequently be extended by cluster once the protocol and compliance are stable.
How can a high renal-risk population be defined in an “auditable” manner?
A high-risk population can be defined using objective criteria such as CKD/eGFR, diabetes, advanced age, previous AKI or repeated exposure to iodine within short periods. Operational thresholds should be established in the protocol and applied consistently. This makes pre/post comparisons and comparisons between procedure rooms defensible within an HTA.
Why is digital traceability of the parameters essential for HTA?
Digital traceability makes processes reproducible and enables audits of patient selection, protocols and procedural parameters. Without traceable data, outcomes remain attributable to the individual operator and the assessment becomes open to interpretation. Standardization is what allows the program to scale beyond a single “champion” team.
How long does it take to develop a credible CO₂ business case for Hospital Management?
A credible business case can be established within 30 days and is typically evaluated over 12–16 weeks using consecutive cohorts and fixed criteria. The key requirements are a homogeneous baseline, completed creatinine follow-up and predefined KPIs. Thresholds and stop rules prevent the project from remaining under observation without a final decision.
Next step: making the Zero Contrast pathway measurable and scalable
When Hospital Management aims to reduce AKI/CIN but is uncertain about what to measure and where to begin, the solution is a narrowly defined operational scope, a shared set of minimum KPIs and digital workflow traceability. Request a CO₂ business case checklist containing the KPIs, minimum dataset and Technology Committee template, together with an implementation assessment with the Angiodroid team to define the protocol, data governance and training plan within two weeks.
Speak with an expert and request the checklist for Hospital Management
