Intensive care units

ICU antibiogram software, unit-specific antibiograms for intensive care, cut from the lab export you already pull

Q: What is a unit-specific antibiogram?

A unit-specific antibiogram is a cumulative susceptibility report built only from isolates collected in one hospital location, most often an intensive care unit. It follows the same CLSI M39 rules as the hospital report, first isolate per patient per organism and at least 30 isolates per cell, but inside the unit's own population.

Q: Should an ICU have its own antibiogram?

Yes, when the unit sees enough isolates. ICU patients differ from the house average in length of stay, devices and prior antibiotics, and one published trauma center comparison found gaps of 15 to 43 points for key respiratory organisms. If a single ICU is too small, combine adult ICUs or pool two years rather than skip it.

Q: How many isolates do you need for an ICU antibiogram?

CLSI M39 advises against reporting percent susceptible on fewer than 30 isolates of an organism in the period. Most mid-size ICUs clear that for Pseudomonas, Staphylococcus aureus and E. coli in a year. For Acinetobacter, Enterobacter or a NICU, pool two or three years and print the window.

Q: Is the first-isolate rule applied before or after the ICU filter?

After. Filter to the ICU first, then keep each patient's first isolate of each organism inside that cut. Applying the rule house-wide and then filtering drops ICU isolates from patients who were first cultured on a floor, which undercounts the unit.

Q: How often should an ICU antibiogram be updated?

At least yearly, like the hospital report, and quarterly if the unit is large enough or a resistance problem is developing. Quarterly cuts suppress more cells, so many teams publish an annual matrix and watch quarterly trend lines for a few key organism and drug pairs.

Q: How much does ICU antibiogram software cost?

Antimicrobe's unit cuts are on the Stewardship plan at $749 a month, with quarterly trends and MDRO alerts included and no implementation fee. The $249 Lab plan builds the hospital-wide antibiogram without unit cuts. Enterprise surveillance platforms that include unit views do not publish prices.

A hospital-wide antibiogram averages the ICU in with every outpatient urine culture in the building. The intensivists choosing empiric therapy for ventilator-associated pneumonia or septic shock need their own unit's numbers, cut by specimen source, refreshed more than once a year, and suppressed where the counts are too thin to trust.

Read the short answer

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Antibiogram Builder

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Source

Unit

Period

Rules

under 40 40 to 59 60 to 74 75 to 89 90 and over n<30, below the reporting threshold n/t, not tested on this panel

Short answer

ICU antibiogram software produces a unit-specific cumulative antibiogram for intensive care from the same susceptibility export the lab uses for the hospital report. Antimicrobe filters to your ICU locations first, then applies the CLSI M39 first-isolate rule inside that cut, suppresses any cell under 30 isolates, and splits respiratory, blood and urine so each can guide a different empiric decision. Unit cuts, quarterly trends and MDRO alerts are on the Stewardship plan at $749 a month.

Computed from your own isolates, never from a national average.

Why the ICU needs a unit-specific antibiogram

Intensive care patients have usually been in hospital longer, carry more devices and have had more antibiotics than the rest of the census, so their isolates rarely match the hospital average. The direction of the difference is not always the one you expect, which is the real argument for measuring it instead of assuming.

At a 283-bed Level I trauma center in Louisiana (Al-Dahir and colleagues, Surgical Infections, 2015, data from 2009 to 2011), respiratory Acinetobacter from the surgical and trauma ICU was far more susceptible than the hospital-wide respiratory antibiogram suggested: imipenem 93 percent versus 55 percent, ciprofloxacin 86 versus 43. Pseudomonas imipenem susceptibility was 94 percent in the unit against 79 hospital-wide. The authors recommended unit- and collection-site-specific antibiograms for comparable institutions.

In other ICUs, especially medical units with long-stay patients, the gap can run the other way, with lower susceptibility than the house-wide figure. Either way, an empiric guideline built on the blended number is aimed at the wrong population, and the error is invisible until someone cuts the data.

What an ICU antibiogram has to get right

A unit cut is not a filter slapped on the finished hospital report. The order of operations changes the numbers, and a pharmacy and therapeutics committee will ask how it was done.

Cut first, then de-duplicate. CLSI M39 counts the first isolate per patient per organism in the period. Apply that rule inside the ICU cut, so a patient whose first isolate came from a medical floor still contributes their first ICU isolate to the ICU report
Assign the unit at collection. The location that ordered the culture defines the cut, not the unit the patient was discharged from. Transfers in and out of the ICU are otherwise counted twice or not at all
Split by specimen source. Tracheal aspirate and bronchoalveolar lavage isolates answer the pneumonia question, blood answers the sepsis question, and urine answers a different one again. A single ICU matrix blends them
Suppress small cells. A 12-bed unit may see fewer than 30 isolates of Acinetobacter or Enterobacter in a year. Those cells are shown as counts, or pooled across two years with the window printed on the report
Leave out surveillance cultures. Admission MRSA nares swabs and CRE rectal screens measure colonization. M39 excludes them from the cumulative report

ICU antibiogram options compared

If the hospital already runs Sentri7, VigiLanz or TheraDoc for alerts, keep it: the Sentri7 alternatives page explains how teams leave the alerting platform in place and move only the antibiogram work out of the analyst queue.

Routes to an ICU antibiogram as a US hospital would compare them. Antimicrobe prices from its pricing page; enterprise platforms do not publish prices.
Option	ICU cut done how	Who does the work	Cost
Hospital-wide antibiogram only	Not cut; ICU blended with everyone	Lab or pharmacy, once a year	No extra cost, wrong population
LIS or EHR report with a location filter	Often filtered after de-duplication	A report writer, when the queue allows	Analyst hours, usually weeks of wait
Excel by hand	Filtered and pivoted by a pharmacist	Stewardship pharmacist, each refresh	No license, days per cut
WHONET	Location filter in the analysis setup	One person on a Windows PC, after BacLink setup	Free software, your hours
Enterprise surveillance platform	Unit views alongside real-time alerts	Vendor implementation with your IT	Not published, platform pricing
Antimicrobe Stewardship	Unit filter applied before the first-isolate rule, per source	Stewardship lead, in a browser	$749 a month

MICU, SICU, CVICU and NICU, which units to cut

Start with the units whose patients differ most from the house average and whose prescribers choose broad empiric therapy most often. For most hospitals that is the medical ICU for pneumonia and sepsis, and the surgical or trauma ICU for post-operative and ventilator-associated infections. Cardiovascular ICUs and burn units follow if volume allows.

Combining units is fine and often necessary. If the MICU and SICU each see 18 Pseudomonas isolates a year, a combined adult ICU report reaches 36 and prints a percentage; separate reports would suppress both cells. Decide the grouping once, print it on the report, and keep it the same year to year so the trend means something.

Neonatal ICUs are a different population with different organisms (group B strep, E. coli, coagulase-negative staph) and much smaller counts. A NICU cut almost always needs two or three years pooled, and it should never be merged with the adult units.

Unit names arrive as free text from the lab, so "MICU", "4 East ICU" and "Med ICU" are grouped once during mapping. The accepted columns and their common LIS names are on the LIS susceptibility export page.

NICU and pediatric unit cuts, with the small-count rules that go with them, are covered on the pediatric antibiogram software page.

Does an ICU antibiogram actually change empiric therapy?

It changes the starting point, which is what it is for. A unit antibiogram tells the team which agents cover most of the organisms their patients grow, so the empiric regimen in the ICU order set rests on local numbers instead of a national guideline table or the house-wide report.

It is not the whole answer. A 2024 Michigan Medicine study (Wangchinda and colleagues, Open Forum Infectious Diseases) compared unit-specific combination antibiograms with a patient-specific risk factor approach for gram-negative ICU pneumonia: appropriate coverage was 83.7 percent with the antibiogram approach and 89.9 percent with the risk-factor approach, and overuse was lower with risk factors. The practical reading is that the unit antibiogram sets the default and prior cultures and antibiotic exposure adjust it for the individual patient.

How the antibiogram feeds the empiric choice is covered on the empiric antibiotic therapy page.

MDRO trends in the ICU between annual reports

An annual report tells the committee what happened last year. The ICU usually needs to know sooner when carbapenem-resistant Enterobacterales, resistant Pseudomonas or MRSA are climbing. The Stewardship plan adds quarterly trend lines for any organism and drug in the ICU cut, and an MDRO watch that flags a quarter crossing a threshold you set, on the same uploaded data.

This is resistance surveillance from finalized susceptibility results. It is not patient-level HAI case finding, it does not submit to NHSN, and it does not page anyone at 2 a.m. Infection prevention keeps those workflows.

The organism-level view is on the carbapenem-resistant organism tracking page, and the wider category on antimicrobial resistance surveillance software.

How it works

The builder at the top of this page runs the same rules on sample data: move the unit filter between outpatient and intensive care and watch the susceptibility columns change before you buy.

Ask the lab for 12 to 24 months of finalized susceptibility results as CSV, all locations, with patient key, collection date, specimen source, unit, organism, antibiotic and S, I or R. MIC values are used when present
Map free-text locations to units once (MICU, SICU, NICU, step-down), and remove screening swabs
Set the unit filter to the ICU grouping and the source to respiratory, blood or urine. The first-isolate rule runs inside that cut and cells under 30 isolates are suppressed
Export the ICU antibiogram with its rule receipt for the critical care committee, and refresh it each quarter from the next export

Which plan fits

Unit cuts are a Stewardship plan feature: $749 a month for up to 3 facilities, 150,000 isolates a year and 8 seats, with source, unit, period and syndrome cuts, quarterly trends, MDRO threshold alerts, and CLSI and EUCAST breakpoint sets. The Lab plan at $249 a month cuts by specimen source and period only, which suits a hospital that wants one defensible annual report but not unit views. A health system that wants each hospital's ICU compared side by side fits the Network plan at $2,400 a month for up to 12 facilities.

Every limit is published on the pricing page. The hospital-wide report, and the other sub-reports that usually come with it, are on hospital antibiogram software.

What this does not do

No EHR or HL7 interface on the Stewardship plan. It works from exported files
No real-time patient alerts, culture follow-up queues or NHSN submission
No combination antibiogram (percent covered by a two-drug regimen); it reports single-agent coverage of the whole cut
Not a prescribing tool. It summarizes susceptibility for the pharmacists and intensivists who set empiric guidance

Questions

On this page's topic

What is a unit-specific antibiogram?

A unit-specific antibiogram is a cumulative susceptibility report built only from isolates collected in one hospital location, most often an intensive care unit. It follows the same CLSI M39 rules as the hospital report, first isolate per patient per organism and at least 30 isolates per cell, but inside the unit's own population.

Should an ICU have its own antibiogram?

Yes, when the unit sees enough isolates. ICU patients differ from the house average in length of stay, devices and prior antibiotics, and one published trauma center comparison found gaps of 15 to 43 points for key respiratory organisms. If a single ICU is too small, combine adult ICUs or pool two years rather than skip it.

How many isolates do you need for an ICU antibiogram?

CLSI M39 advises against reporting percent susceptible on fewer than 30 isolates of an organism in the period. Most mid-size ICUs clear that for Pseudomonas, Staphylococcus aureus and E. coli in a year. For Acinetobacter, Enterobacter or a NICU, pool two or three years and print the window.

Is the first-isolate rule applied before or after the ICU filter?

After. Filter to the ICU first, then keep each patient's first isolate of each organism inside that cut. Applying the rule house-wide and then filtering drops ICU isolates from patients who were first cultured on a floor, which undercounts the unit.

How often should an ICU antibiogram be updated?