Key takeaways
- The Rodwell Hematological Score (RHS), developed in 1988, converts a standard admission complete blood count into a sepsis risk predictor within minutes to hours, bridging the diagnostic gap before blood culture results at 48+ hours.
- A score of <=2 points (Green Zone) yields a negative predictive value of 99%, giving neonatologists high confidence to safely exclude sepsis and avoid empirical antibiotics.
- A score of >=5 points (Red Zone) is highly predictive of sepsis, with 83.3% of confirmed cases falling in this range, while a score of 3-4 (Yellow Zone) carries a 31%-65% probability of sepsis.
- RHS performs even better in preterm infants (57% predictive accuracy) than term infants (43%), with recent studies confirming NPVs between 93% and 100% in premature neonates.
- The RHS integrates 7 hematological parameters across 3 blocks (total leukocytes/neutrophils, left shift indices, and thrombocytopenia/toxic changes) into an actionable 0-8 point scale.
References
- Rodwell et al., 1988
- PMC3761960
- Klaus & Fanaroff
Neonatal Sepsis Screening
The applicability of the Rodwell Hematological Score (RHS)
Diagnostic Vacuum in the First 48 Hours
Neonatal sepsis is rapid and often fatal.
The central dilemma in the NICU occurs right at admission.
Diagnostic Vacuum
- Time 0: Clinical Suspicion — Rapid systemic deterioration.
- Hour 48+: Blood Culture Result — Gold standard, but slow to be confirmed.
The Cost of Uncertainty: Antimicrobial Resistance (AMR)
Exponential increase in multidrug-resistant bacteria (MRSA, ESBL).
The maxim “when in doubt, prescribe” is no longer safe. The empirical and prolonged use of antibiotics has created an ecosystem crisis in NICUs.
Lethal alteration of the gut microbiome, increasing the risk of Necrotizing Enterocolitis (NEC).
Critical Fact: Of the 40 antibiotics approved for adults since the year 2000, only 4 included dosage information for neonates. The arsenal is running out.
Rodwell Hematological Score (RHS)
Developed in 1988, the RHS transforms a simple admission blood count into a powerful predictor of sepsis risk.
Speed
Results in minutes to hours, safely covering the time gap of blood cultures.
Low Cost
It uses only parameters from the standard automated blood count and peripheral blood smear review.
Objectivity
It standardizes cellular interpretation, removing subjectivity from neonatal hematological diagnosis.
NeoFast App: Rodwell Score Calculator
Other calculations and scores
- Reference values — Laboratory, vital signs and measurements by age
Recent
- Endotracheal tube diameter — Cave and team (2016)
- Normal CSF values in newborns
- Premature baby’s growth
- Rodwell score — Neonatal sepsis
- Tracheal tube insertion
Calculations
- Apgar Score
- Body surface area — Weight e height
Rodwell score – Neonatal sepsis
Does the patient have leukocytosis or leukopenia?
- Leukocytes <= 5,000/mm³ or >= 25,000/mm³ at birth.
- Leukocytes >= 30,000/mm³ in 12-24h of life.
- Leukocytes >= 21,000/mm³ after 48h of life.
Does the patient have neutropenia or …
- …or below 7,800/mm3 up to 60 …or 1,750/mm3 after.
- …or above 14,500/mm3 up to …400/mm3 after.
…rophils visible?
The patient has an increased immature/total neutrophil ratio > 0.12?
- >0.16 in the first 24
- >0.13 between 24-60 hours of life
- >0.12 over 60 hours of life
Does the patient have platelets <= 150,000/mm³?
0/9 questions answered. Answer all the questions to get the result.
Block 1 & 2: Defense Volume and Left Shift
Block 1: The Defense Volume
The first two parameters of the RHS analyze the total contingent of the circulating immune army.
[Parameter 1] –> Total Leukocytes – Abnormality scores 1.
(Abnormal values: <= 5,000 or higher according to the hours of life table).
[Parameter 2] –> Total Neutrophils (PMN) – An abnormal count scores 1.
If no mature neutrophils are visible on the slide, parameter 2 receives 2 points to compensate for the impossible calculation of subsequent proportions.
Block 2: The Left Shift (Immature)
The tool’s greatest strength lies in its painstakingly stimulating bone marrow efforts to release young cells.
- [Parameter 3] Total Immature PMNs — Raised by 1 point. (Presence of metamyelocytes, band cells, etc.) Highest isolated sensitivity: 96.87%.
- [Parameter 4] I:T Ratio — Immature/Total high = 1 point. (0 classic high sensitivity index for systemic infection).
- [Parameter 5] I:M Ratio — Immature/Mature >= 0.3 = 1 point. (0 indicator with greater specificity isolated: 97.22%).
Block 3: Stress and Toxic Changes
Block 3: Stress and Cell Phone Consumption
Physical signs of immune system depletion and severe inflammation.
[Parameter 6] Thrombocytopenia Count <= 150,000/mm³ = 1 point.
Clear sign of coagulopathy and peripheral consumption.
[Parameter 7] Toxic Changes
Pronounced presence = 1 point.
- Toxic Granulations
- Vacuolization
- Döhle corpuscles
Clinical Risk Meter (Score 0-8)
Clinical Risk Meter (Score 0-8)
The conversion of the 7 cellular parameters into an immediate and actionable risk stratification.
- <= 2 Points — Green Zone: Unlikely Sepsis. High security for exclusion.
- 3 to 4 points — Yellow Zone: Possible Sepsis. Probability rises to 31%-65%.
- >= 5 Points — Red Zone: Sepsis Very Likely. 83.3% of confirmed cases occur in this zone.
NeoFast App: Score Results
Rodwell score – Neonatal sepsis
The patient has an increased immature/total neutrophil ratio > 0.12?
- >0.16 in the first 24
- >0.13 between 24-60 hours of life
- >0.12 over 60 hours of life
Does the patient have platelets <= 150,000/mm³?
Score: 2 — Diagnosis of neonatal sepsis is highly unlikely.
Note: score >= 3: sensitivity 96% and specificity … of 0, 1 or 2: negative predictive value = 99%.
Score: 3 — Diagnosis of neonatal sepsis is moderately likely.
Note: score >= 3: sensitivity 96% and specificity 78%. Score …negative predictive value = 99%.
Score: 8 — Diagnosis of neonatal sepsis is highly likely.
NeoFast indicates the likely diagnosis according to each score.
Security to Exclude
Security to Exclude
The clinical virtue of the tool is not only to diagnose, but to give absolute confidence in ruling out infection.
99%
Negative Predictive Value (NPV) for Scores <= 2.
The probability of absence of sepsis when the score is less than or equal to 2 reaches 99% (Rodwell et al., 1988).
Recent studies confirm robust predictive potentials (NPVs) between 93% and 100%. This is the neonatologist’s protective shield against empirical overtreatment.
Superior Performance Among the Most Vulnerable
Superior Performance Among the Most Vulnerable: RHS shines brightest precisely in the population at highest risk.
Predictive Accuracy of RHS (Term vs. Preterm)
- Newborns Term: 43% Accuracy
- Newborns Preterm: 57% Accuracy
The baseline immaturity of the premature immune system makes the inflammatory deviations mathematically more glaring on the slide.
Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) are systemically higher in the premature population (PMC3761960).
Paradigm Shift
Paradigm Shift
How adopting the Rodwell Score radically alters the trajectory of a suspected patient.
| The Traditional Approach | The RHS Approach |
|---|---|
| Wait 48 hours for the blood culture results. | Clear hematological response in just 2 hours. |
| Empirical antibiotic administered to ALL suspected cases. | A score of <= 2 excludes acute sepsis with >93% certainty. |
| Consequences: Irreversible damage to microbiome, prolonged central catheter time, high cost, and active promotion of resistance. | Consequences: Safe clinical monitoring WITHOUT antibiotics, protection of the intestinal flora, and a significant reduction in hospital stay. |
“With modern techniques, if cultures are negative and the clinical condition allows, antibiotics should be discontinued between 24-36 hours, abandoning the old practice of 72 hours.”
Based on the guidelines of Klaus & Fanaroff.
- RHS <= 2 (High Trust)
- Reduction of Antibiotic Empirical
- Preservation of the Microbiome Neonatal
- Prevention of NEC and Reduction AMR Pressure
Integrated Clinical Decision Algorithm
Integrated Clinical Decision Algorithm
Incorporating RHS into the daily workflow for early-onset sepsis screening in the NICU.
- Newborn at risk maternal or clinical suspicion
- Blood Culture Collection + Complete Blood Count (HSS Calculation)
RHS >= 3: Start and continue antibiotics, empirical. Wait for the culture results for 48 hours.
RHS <= 2 And clinically stable: Safe omission of antibiotics OR ultra-rapid de-escalation (discontinue within 24 hours). Continuous monitoring.
A New Culture of Care
The Rodwell Hematology Score draws wisdom from simple data, protecting the patient from two threats: infection and healing itself.
- Validated tool with up to 100% NPV in premature neonates.
- It allows the transition from empirical fear to evidence-based stewardship.
Implement routine RHS calculation in your NICU today. Protecting our antibiotics is protecting the future of our newborns.
Neofast App – Rodwell Score
Neofast App
Intuitive, fast and secure.
Check it out!
- Venous hydration
- Continuous medication
- Medicines
- Intubation
- Other calculations and scores
- Procedures
- Respiratory and hemodynamic monitoring
- Growth and Development
Other calculations and scores
- Reference values: Laboratory, vital signs and measurements by age
Recent
- Endotracheal tube diameter — Care and team (2016)
- Normal CSF values in newborns
- Premature baby’s growth rate
- Rodwell score — Neonatal sepsis
- Tracheal tube insertion depth
Calculations
- Apgar Score
- Body surface area — Weight e height
- Body surface area — Weight only
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Get it on Google Play
Frequently asked questions
What is the Rodwell Hematological Score and why was it developed?
The RHS, developed in 1988, transforms a simple admission blood count into a powerful predictor of neonatal sepsis risk, filling the diagnostic vacuum between clinical suspicion at Time 0 and the blood culture gold standard result available only at 48+ hours.
What are the 7 parameters scored in the Rodwell Hematological Score?
The RHS scores: (1) Total Leukocytes, (2) Total Neutrophils (PMN), (3) Total Immature PMNs, (4) I:T Ratio, (5) I:M Ratio >=0.3, (6) Thrombocytopenia <=150,000/mm3, and (7) Toxic Changes (toxic granulations, vacuolization, Dohle corpuscles). Most abnormal parameters score 1 point, except if no mature neutrophils are visible, which scores 2 points for parameter 2.
What do the RHS score zones mean for antibiotic decisions?
A score <=2 (Green Zone) means sepsis is unlikely with a 99% negative predictive value, supporting safe omission of antibiotics or de-escalation within 24 hours. A score of 3-4 (Yellow Zone) indicates possible sepsis (31%-65% probability). A score >=5 (Red Zone) means sepsis is very likely, with 83.3% of confirmed cases occurring in this zone, warranting continued empirical antibiotics pending 48-hour culture results.
How accurate is the RHS in preterm versus term infants?
RHS predictive accuracy is 57% in preterm newborns versus 43% in term newborns, with sensitivity, specificity, PPV, and NPV systemically higher in the premature population, and NPVs reported between 93% and 100% in some studies (PMC3761960).
How does using RHS change the traditional approach to suspected neonatal sepsis?
Instead of waiting 48 hours for blood cultures and giving empirical antibiotics to all suspected cases, RHS provides a clear hematological response within 2 hours; a score <=2 excludes acute sepsis with >93% certainty, enabling safe clinical monitoring without antibiotics, protecting the microbiome, and reducing hospital stay and antimicrobial resistance pressure.
