Medical Calculators

Emergency Medicine Clinical Calculators

Interactive scoring tools for clinical decision-making at the bedside. Select responses below and scores will calculate automatically. Each calculator is a template that can also be placed on its relevant topic page.

Contents [show]

1. Cardiac — HEART • CHA₂DS₂-VASc • HAS-BLED • TIMI • QTc

2. Pulmonary — Wells PE • PERC • CURB-65 • Light's

3. Vascular — Wells DVT • Shock Index

4. Neurological — GCS • NIHSS • Fisher • Canadian CT Head • ABCD2

5. ID/Sepsis — qSOFA • SIRS • LRINEC

6. GI/Hepatic — Alvarado • Ranson's • MELD • Child-Pugh

7. Tox/Withdrawal — CIWA-Ar

8. Syncope — SF Syncope

9. ENT — Centor

10. Renal/Lytes — Anion Gap • FENa • Winters' • Osm Gap • Corrected Na • CrCl • Na Deficit

11. Ortho/Trauma — Ottawa Ankle • Ottawa Knee • NEXUS • Canadian C-Spine • Parkland

12. Pediatrics — PECARN • APGAR

13. Dosing — BMI/BSA • IBW • Maintenance Fluids • Schwartz

Cardiac

HEART Score

HEART Score Calculator

Criteria	Select One
History	Slightly suspicious (0)	Moderately suspicious (+1)	Highly suspicious (+2)
EKG	Normal (0)	Non-specific repolarization disturbance (+1)	Significant ST deviation (+2)
Age	<45 (0)	45–64 (+1)	≥65 (+2)
Risk Factors HTN, hypercholesterolemia, DM, obesity (BMI >30), smoking, family hx CVD, or hx atherosclerotic disease	No known risk factors (0)	1–2 risk factors (+1)	≥3 risk factors or hx atherosclerotic disease (+2)
Initial Troponin	≤normal limit (0)	1–3× normal limit (+1)	>3× normal limit (+2)
HEART Score	/ 10

Interpretation

0–3	Low Risk — 0.9–1.7% risk of MACE. Consider discharge with outpatient follow-up.
4–6	Moderate Risk — 12–16.6% risk of MACE. Consider admission for observation and further workup.
7–10	High Risk — 50–65% risk of MACE. Consider early invasive measures (cardiology consult, catheterization).

References

Six AJ, Backus BE, Kelder JC. Chest pain in the emergency room: value of the HEART score. Neth Heart J. 2008;16(6):191-196. PMID 18665203. Backus BE, Six AJ, Kelder JC, et al. Prospective validation of the HEART score for chest pain patients. Int J Cardiol. 2013;168(3):2153-2158. PMID 23465250. Mahler SA, Riley RF, Hiestand BC, et al. The HEART Pathway randomized trial. Circ Cardiovasc Qual Outcomes. 2015;8(2):195-203. PMID 25737484.

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CHA₂DS₂-VASc Score

CHA₂DS₂-VASc Score Calculator

Criteria	No (0)	Yes
Congestive heart failure (or LVEF ≤40%)	1	(+1)
Hypertension	1	(+1)
Age ≥75 years	1	(+2)
Diabetes mellitus	1	(+1)
Stroke/TIA/thromboembolism	1	(+2)
Vascular disease (prior MI, PAD, aortic plaque)	1	(+1)
Age 65–74 years	1	(+1)
Sex category (female)	1	(+1)
CHA₂DS₂-VASc Score	/ 9

Interpretation
0	Low Risk — 0.2% annual stroke risk (males). Anticoagulation generally not recommended.
1	Low-Moderate Risk — 0.6% annual stroke risk (males). Consider anticoagulation (esp. if not due to female sex alone).
≥2	Moderate-High Risk — ≥2.2% annual stroke risk. Oral anticoagulation recommended.

References

Lip GY, Nieuwlaat R, Pisters R, et al. Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation using a novel risk factor-based approach: the Euro Heart Survey on Atrial Fibrillation. Chest. 2010;137(2):263-272. PMID 19762550. January CT, Wann LS, Calkins H, et al. 2019 AHA/ACC/HRS Focused Update of the 2014 Guideline for Management of Patients With Atrial Fibrillation. J Am Coll Cardiol. 2019;74(1):104-132. PMID 30703431.

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HAS-BLED Score

HAS-BLED Score — Bleeding Risk

Criteria	No (0)	Yes (+1)
H — Hypertension (uncontrolled SBP >160)	1
A — Abnormal renal function (dialysis, transplant, Cr >2.26) and/or liver function (cirrhosis, bilirubin >2×, AST/ALT/ALP >3×)	1	(+1 each, max 2)
S — Prior stroke	1
B — Bleeding history/predisposition	1
L — Labile INR (unstable/high, TTR <60%)	1
E — Elderly (age >65)	1
D — Drugs (antiplatelets, NSAIDs) and/or alcohol (≥8 drinks/week)	1	(+1 each, max 2)
HAS-BLED Score	/ 9

Interpretation
0–2	Low-moderate risk — Relatively low bleeding risk. Anticoagulation generally recommended if indicated.
≥3	High risk — Consider modifiable risk factors (HTN, labile INR, drugs/alcohol). Score ≥3 does NOT contraindicate anticoagulation but warrants closer monitoring.

References
Pisters R, Lane DA, Nieuwlaat R, et al. A novel user-friendly score (HAS-BLED) to assess 1-year risk of major bleeding in patients with atrial fibrillation. Chest. 2010;138(5):1093-1100. PMID 20299623. Note: HAS-BLED ≥3 is NOT a contraindication to anticoagulation — it identifies patients who need closer follow-up and correction of modifiable risk factors.

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TIMI UA/NSTEMI Score

TIMI Risk Score for UA/NSTEMI

Risk Factor	No (0)	Yes (+1)
Age ≥65 years	1
≥3 CAD risk factors (HTN, DM, hyperlipidemia, family hx, smoking)	1
Known CAD (stenosis ≥50%)	1
ASA use in past 7 days	1
Severe angina (≥2 episodes in 24h)	1
ST deviation ≥0.5mm	1
Positive cardiac marker (troponin)	1
TIMI Score	/ 7

Interpretation
0-2	Low risk — 4.7-8.3% risk of all-cause mortality, new/recurrent MI, or severe ischemia at 14 days.
3-4	Moderate risk — 13.2-19.9% risk. Consider early invasive strategy.
5-7	High risk — 26.2-40.9% risk. Early invasive strategy recommended.

References
Antman EM, Cohen M, Bernink PJ, et al. The TIMI risk score for unstable angina/non-ST elevation MI. JAMA. 2000;284(7):835-842. PMID 10938172.

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Corrected QT Interval (QTc)

Corrected QT Interval (QTc)

Parameter	Value
QT Interval (ms)
Heart Rate (bpm)
RR Interval (ms) — auto-calculated from HR	ms
Results
QTc (Bazett's) — QT / √(RR in sec)	ms
QTc (Fridericia) — QT / ∛(RR in sec)	ms

Interpretation (Bazett's QTc)
<440 ms	Normal QTc for males.
<460 ms	Normal QTc for females.
440–500 ms	Borderline/Prolonged — Monitor closely. Review medications for QT-prolonging drugs.
>500 ms	Significantly prolonged — High risk for Torsades de Pointes. Discontinue offending agents. Check Mg²⁺/K⁺/Ca²⁺.

References
Bazett HC. An analysis of the time-relations of electrocardiograms. Heart. 1920;7:353-370. Fridericia LS. Duration of systole in electrocardiogram. Acta Med Scand. 1920;53:469-486. Viskin S. Long QT syndromes and torsade de pointes. Lancet. 1999;354:1625-1633. PMID 10560690.

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Pulmonary

Wells Score for PE

Wells' PE Score Calculator

Criteria	No	Yes	Points
Clinical signs and symptoms of DVT (leg swelling, pain with palpation)	1		+3.0
PE is #1 diagnosis OR equally likely	1		+3.0
Heart rate >100 bpm	1		+1.5
Immobilization (≥3 days) OR surgery in previous 4 weeks	1		+1.5
Previous objectively diagnosed PE or DVT	1		+1.5
Hemoptysis	1		+1.0
Malignancy (treatment within 6 months or palliative)	1		+1.0
Wells' Score	points

Three-Tier Model

0–1	Low Risk — 1.3% incidence of PE. Consider D-dimer to rule out. Consider PERC rule.
2–6	Moderate Risk — 16.2% incidence of PE. Consider high-sensitivity D-dimer or CTA.
>6	High Risk — 37.5% incidence of PE. Consider CTA. D-dimer not recommended.

Two-Tier Model (Preferred by guidelines)

0–4	PE Unlikely — 12.1% incidence. Consider high-sensitivity D-dimer; if negative, stop workup.
>4	PE Likely — 37.1% incidence. Consider CTA testing.

References

Wells PS, Anderson DR, Rodger M, et al. Derivation of a simple clinical model to categorize patients probability of pulmonary embolism. Thromb Haemost. 2000;83(3):416-420. PMID 10744147. van Belle A, Büller HR, Huisman MV, et al. Effectiveness of managing suspected pulmonary embolism using an algorithm combining clinical probability, D-dimer testing, and computed tomography. JAMA. 2006;295(2):172-179. PMID 16403929.

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PERC Rule

PERC Rule Calculator

Criteria	No (0)	Yes (+1)
Age ≥50 years	1
Heart rate ≥100 bpm	1
SpO₂ <95% on room air	1
Unilateral leg swelling	1
Hemoptysis	1
Recent surgery or trauma (within 4 weeks requiring hospitalization)	1
Prior PE or DVT	1
Hormone use (oral contraceptives, HRT, or estrogenic hormones)	1
Positive Criteria	/ 8

Interpretation

Score = 0	PERC Negative — If pre-test probability is ≤15%, PE is effectively ruled out. No further workup needed (sensitivity 97.4%, NPV 99.5%).
Score ≥ 1	PERC Positive — Cannot rule out PE by PERC alone. Consider D-dimer, Wells' score, or CTA based on clinical suspicion.

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CURB-65 Score

CURB-65 Calculator

Criteria	No (0)	Yes (+1)
Confusion (new disorientation in person, place, or time)	1
Uremia — BUN >19 mg/dL (>7 mmol/L)	1
Respiratory rate ≥30 breaths/min	1
Blood pressure — SBP <90 mmHg or DBP ≤60 mmHg	1
Age ≥65 years	1
CURB-65 Score	/ 5

Interpretation & Disposition

0–1	Low Risk — 1.5% 30-day mortality. Consider outpatient treatment with oral antibiotics.
2	Moderate Risk — 9.2% 30-day mortality. Consider short inpatient stay or closely monitored observation.
3–5	High Risk — 22% 30-day mortality. Inpatient admission recommended. ICU if score 4–5.

References
Lim WS et al. Defining community acquired pneumonia severity. Thorax. 2003;58(5):377-382. PMID 12728155. Mandell LA et al. IDSA/ATS consensus guidelines on CAP. Clin Infect Dis. 2007;44:S27-72. PMID 17278083.

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Light's Criteria

Light's Criteria — Pleural Effusion

Parameter	Value
Pleural fluid protein (g/dL)
Serum protein (g/dL)
Pleural fluid LDH (IU/L)
Serum LDH (IU/L)
Upper limit of normal serum LDH (IU/L)
Results
Pleural protein / Serum protein ratio
Pleural LDH / Serum LDH ratio
Pleural LDH / ULN serum LDH

Interpretation
Exudative (any 1 of:)	Pleural protein/serum protein > 0.5 OR Pleural LDH/serum LDH > 0.6 OR Pleural LDH > 2/3 ULN serum LDH. Causes: infection, malignancy, PE, autoimmune, etc.
Transudative	None of the above criteria met. Causes: CHF, cirrhosis, nephrotic syndrome, PE.

References
Light RW, Macgregor MI, Luchsinger PC, et al. Pleural effusions: the diagnostic separation of transudates and exudates. Ann Intern Med. 1972;77(4):507-513. PMID 4642731.

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Vascular

Wells Score for DVT

Wells' Criteria for DVT

Criteria	No	Yes	Points
Active cancer (treatment within 6 months or palliative)	1		+1
Bedridden recently >3 days or major surgery within 12 weeks	1		+1
Calf swelling >3 cm compared to other leg (measured 10 cm below tibial tuberosity)	1		+1
Collateral superficial veins (non-varicose)	1		+1
Entire leg swollen	1		+1
Localized tenderness along deep venous system	1		+1
Pitting edema confined to symptomatic leg	1		+1
Paralysis, paresis, or recent cast immobilization of lower extremities	1		+1
Previously documented DVT	1		+1
Alternative diagnosis at least as likely as DVT	1		−2
Wells' Score	points

Interpretation (Traditional)
≤0	Low Risk — 5% prevalence of DVT. Consider D-dimer to rule out.
1–2	Moderate Risk — 17% prevalence of DVT. Consider D-dimer or ultrasound.
≥3	High Risk — 53% prevalence of DVT. Ultrasound recommended.
Interpretation (Dichotomized)
≤1	DVT Unlikely — D-dimer to rule out.
≥2	DVT Likely — Ultrasound recommended.

References
Wells PS et al. Value of assessment of pretest probability of DVT. Lancet. 1997;350:1795-1798. PMID 9428249. Wells PS et al. Evaluation of D-dimer in suspected DVT. N Engl J Med. 2003;349:1227-1235. PMID 14507948.

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Shock Index

Shock Index

Parameter	Value
Heart Rate (bpm)
Systolic Blood Pressure (mmHg)
Shock Index (HR/SBP)

Interpretation
0.5–0.7	Normal — Normal physiologic range.
0.7–1.0	Elevated — May indicate early/compensated shock. Consider further evaluation.
1.0–1.4	High — Consistent with significant hemodynamic compromise. Consider aggressive resuscitation.
>1.4	Critical — High mortality risk. Immediate intervention required.

References
Allgower M, Burri C. Shock index. Dtsch Med Wochenschr. 1967;92:1947-1950. PMID 5299769. Cannon CM et al. Utility of the shock index in predicting mortality in traumatically injured patients. J Trauma. 2009;67:1426-1430. PMID 20009697.

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Neurological

Glasgow Coma Scale (GCS)

Glasgow Coma Scale Calculator

Component	Response	Points
Eye Opening (E)	Spontaneous	+4
	To verbal command	+3
	To pain	+2
	No eye opening	+1
Verbal Response (V)	Oriented	+5
	Confused	+4
	Inappropriate words	+3
	Incomprehensible sounds	+2
	No verbal response	+1
Motor Response (M)	Obeys commands	+6
	Localizes pain	+5
	Withdrawal from pain	+4
	Flexion to pain (decorticate)	+3
	Extension to pain (decerebrate)	+2
	No motor response	+1
GCS Score	/ 15

Interpretation

13–15	Mild brain injury
9–12	Moderate brain injury
3–8	Severe brain injury — consider intubation if unable to protect airway

References
Teasdale G, Jennett B. Assessment of coma and impaired consciousness. Lancet. 1974;2:81-84. PMID 4136544. Teasdale G et al. The Glasgow Coma Scale at 40 years. Lancet Neurol. 2014;13:844-854. PMID 25030516.

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NIH Stroke Scale (NIHSS)

NIH Stroke Scale (NIHSS)

Category	Select Score
1a. Level of Consciousness	1 Alert (0)   Not alert, arousable (1)   Not alert, obtunded (2)   Unresponsive (3)
1b. LOC Questions (month, age)	1 Both correct (0)   One correct (1)   Neither correct (2)
1c. LOC Commands (open/close eyes, grip/release)	1 Both correct (0)   One correct (1)   Neither correct (2)
2. Best Gaze (horizontal)	1 Normal (0)   Partial gaze palsy (1)   Forced deviation (2)
3. Visual (visual fields)	1 No visual loss (0)   Partial hemianopia (1)   Complete hemianopia (2)   Bilateral hemianopia (3)
4. Facial Palsy	1 Normal (0)   Minor paralysis (1)   Partial paralysis (2)   Complete paralysis (3)
5a. Motor Arm — Left (drift)	1 No drift (0)   Drift (1)   Some effort against gravity (2)   No effort against gravity (3)   No movement (4)
5b. Motor Arm — Right	1 No drift (0)   Drift (1)   Some effort against gravity (2)   No effort against gravity (3)   No movement (4)
6a. Motor Leg — Left	1 No drift (0)   Drift (1)   Some effort against gravity (2)   No effort against gravity (3)   No movement (4)
6b. Motor Leg — Right	1 No drift (0)   Drift (1)   Some effort against gravity (2)   No effort against gravity (3)   No movement (4)
7. Limb Ataxia	1 Absent (0)   Present in one limb (1)   Present in two limbs (2)
8. Sensory	1 Normal (0)   Mild-moderate loss (1)   Severe/total loss (2)
9. Best Language	1 No aphasia (0)   Mild-moderate aphasia (1)   Severe aphasia (2)   Mute/global aphasia (3)
10. Dysarthria	1 Normal (0)   Mild-moderate (1)   Severe/mute (2)
11. Extinction/Inattention	1 No abnormality (0)   Inattention to one modality (1)   Profound neglect (2)
NIHSS Total	/ 42

Interpretation
0	No stroke symptoms.
1–4	Minor stroke.
5–15	Moderate stroke.
16–20	Moderate-severe stroke.
21–42	Severe stroke.

References
Brott T, Adams HP Jr, et al. Measurements of acute cerebral infarction: a clinical examination scale. Stroke. 1989;20(7):864-870. PMID 2749846. Lyden P, et al. NIHSS Training and Certification Using a Reliable Web-Based Tool. Stroke. 2009;40(8):2507-2511. Note: NIHSS ≥6 is commonly used threshold for thrombolytic eligibility consideration.

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Modified Fisher Scale

Modified Fisher Scale — SAH Vasospasm Risk

CT Findings	Select Grade
Grade	1 Grade 0 — No SAH or IVH (0) Grade 1 — Thin SAH, no IVH (1) Grade 2 — Thin SAH with IVH (2) Grade 3 — Thick SAH, no IVH (3) Grade 4 — Thick SAH with IVH (4)
Modified Fisher Grade

Interpretation — Risk of Symptomatic Vasospasm
Grade	Vasospasm Risk	Description
0 | ~0% | No subarachnoid blood detected.
1 | ~24% | Focal or diffuse thin SAH, no intraventricular hemorrhage (IVH).
2 | ~33% | Focal or diffuse thin SAH with IVH.
3 | ~33% | Focal or diffuse thick SAH (>1mm), no IVH.
4 | ~40% | Focal or diffuse thick SAH with IVH. Highest vasospasm risk.

References
Fisher CM, Kistler JP, Davis JM. Relation of cerebral vasospasm to subarachnoid hemorrhage visualized by computerized tomographic scanning. Neurosurgery. 1980;6(1):1-9. PMID 7354892. Frontera JA, Claassen J, Schmidt JM, et al. Prediction of symptomatic vasospasm after subarachnoid hemorrhage: the modified Fisher scale. Neurosurgery. 2006;59(1):21-27. PMID 16823296.

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Canadian CT Head Rule

Canadian CT Head Rule

High Risk (for neurosurgical intervention)
Criteria	No	Yes
GCS <15 at 2 hours after injury	1
Suspected open or depressed skull fracture	1
Any sign of basal skull fracture (hemotympanum, raccoon eyes, CSF otorrhea/rhinorrhea, Battle sign)	1
Vomiting ≥2 episodes	1
Age ≥65 years	1
Medium Risk (for brain injury on CT)
Amnesia before impact >30 min	1
Dangerous mechanism (pedestrian struck, occupant ejected, fall from ≥3 feet or ≥5 stairs)	1
High Risk Criteria	/ 5
Medium Risk Criteria	/ 2

Interpretation
All No	CT NOT required — Low risk for clinically important brain injury. Safe for discharge with head injury instructions.
Medium risk ≥1	CT recommended — Risk of brain injury on CT. Imaging indicated.
High risk ≥1	CT required — High risk for neurosurgical intervention. Urgent CT head.

References

Stiell IG, Wells GA, Vandemheen K, et al. The Canadian CT Head Rule for patients with minor head injury. Lancet. 2001;357(9266):1391-1396. PMID 11356436. Stiell IG, Clement CM, Rowe BH, et al. Comparison of the Canadian CT Head Rule and the New Orleans Criteria in patients with minor head injury. JAMA. 2005;294(12):1511-1518. PMID 16189364. Inclusion criteria: GCS 13-15, age ≥16, injury within 24 hours, witnessed LOC/amnesia/disorientation.

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ABCD2 Score for TIA

ABCD2 Score — TIA Stroke Risk

Criteria	Select
A — Age	1 <60 years (0)   ≥60 years (+1)
B — Blood Pressure	1 SBP <140 and DBP <90 (0)   SBP ≥140 or DBP ≥90 (+1)
C — Clinical Features	1 Other symptoms (0)   Speech disturbance without weakness (+1)   Unilateral weakness (+2)
D — Duration of symptoms	1 <10 minutes (0)   10–59 minutes (+1)   ≥60 minutes (+2)
D — Diabetes	1 No (0)   Yes (+1)
ABCD2 Score	/ 7

Interpretation — 2-Day Stroke Risk After TIA
0–3	Low risk — 1.0% risk of stroke within 2 days.
4–5	Moderate risk — 4.1% risk. Consider urgent workup and admission.
6–7	High risk — 8.1% risk. Admit for urgent evaluation and treatment.

References
Johnston SC, Rothwell PM, Nguyen-Huynh MN, et al. Validation and refinement of scores to predict very early stroke risk after transient ischaemic attack. Lancet. 2007;369(9558):283-292. PMID 17258668.

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Infectious Disease / Sepsis

qSOFA Score

qSOFA (Quick SOFA) Score

Criteria	No (0)	Yes (+1)
Altered mental status (GCS <15)	0	1
Respiratory rate ≥22 breaths/min	0	1
Systolic BP ≤100 mmHg	0	1
qSOFA Score	0   / 3

Interpretation
0–1	Low Risk — Not high risk for in-hospital mortality. Continue standard evaluation.
≥2	High Risk — Associated with ≥10% in-hospital mortality. Consider ICU-level care, lactate, blood cultures, and broad-spectrum antibiotics.

References
Singer M et al. Sepsis-3 Definitions. JAMA. 2016;315(8):801-810. PMID 26903338. Seymour CW et al. Assessment of clinical criteria for sepsis. JAMA. 2016;315(8):762-774. PMID 26903335.

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SIRS Criteria

SIRS Criteria

Criteria	No (0)	Yes (+1)
Temperature >38°C (100.4°F) or <36°C (96.8°F)	1
Heart rate >90 bpm	1
Respiratory rate >20 breaths/min or PaCO₂ <32 mmHg	1
WBC >12,000/mm³ or <4,000/mm³ or >10% bands	1
SIRS Criteria Met	/ 4

Interpretation
0–1	SIRS criteria NOT met — Fewer than 2 criteria present.
≥2	SIRS criteria MET — If infection is suspected or confirmed, meets criteria for sepsis (per Sepsis-1/2 definition). Note: Sepsis-3 uses qSOFA/SOFA criteria instead.

References
Bone RC et al. Definitions for sepsis and organ failure. Chest. 1992;101:1644-1655. PMID 1303622. Kaukonen KM et al. SIRS criteria in defining severe sepsis. N Engl J Med. 2015;372:1629-1638. PMID 25776936.

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LRINEC Score

LRINEC Score — Necrotizing Soft Tissue Infection

Lab Value	Select
CRP (mg/L)	1 <150 (0)   ≥150 (+4)
WBC (×10³/μL)	1 <15 (0)   15–25 (+1)   >25 (+2)
Hemoglobin (g/dL)	1 >13.5 (0)   11–13.5 (+1)   <11 (+2)
Sodium (mEq/L)	1 ≥135 (0)   <135 (+2)
Creatinine (mg/dL)	1 ≤1.6 (0)   >1.6 (+2)
Glucose (mg/dL)	1 ≤180 (0)   >180 (+1)
LRINEC Score	/ 13

Interpretation
<6	Low risk — <50% probability of necrotizing fasciitis. Consider other diagnoses but maintain clinical suspicion.
6–7	Moderate risk — 50–75% probability. Consider surgical consultation and advanced imaging.
≥8	High risk — >75% probability of necrotizing fasciitis. Urgent surgical consultation for exploration.

References
Wong CH, Khin LW, Heng KS, et al. The LRINEC (Laboratory Risk Indicator for Necrotizing Fasciitis) score: a tool for distinguishing necrotizing fasciitis from other soft tissue infections. Crit Care Med. 2004;32(7):1535-1541. PMID 15241098. Caution: LRINEC has limited sensitivity (~80%). A low score does NOT rule out necrotizing fasciitis. Clinical suspicion should always guide management.

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Gastrointestinal / Hepatic

Alvarado Score

Alvarado Score (MANTRELS)

Criteria	Points	No	Yes
Symptoms
Migration of pain to RLQ	+1	1
Anorexia	+1	1
Nausea/vomiting	+1	1
Signs
Tenderness in RLQ	+2	1
Rebound pain	+1	1
Elevated temperature (≥37.3°C / 99.1°F)	+1	1
Labs
Leukocytosis (WBC >10,000/μL)	+2	1
Left shift (>75% neutrophils)	+1	1
Alvarado Score	/ 10

Interpretation
0–4	Low risk — Appendicitis unlikely. Consider other diagnoses.
5–6	Equivocal — Consider CT imaging or observation with serial exams.
7–8	Probable appendicitis — Surgical consultation recommended.
9–10	Very probable appendicitis — Operative management almost certain.

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Ranson's Criteria

Ranson's Criteria — Pancreatitis Severity

At Admission (GA-LAW)
Criteria	Points	No	Yes
Glucose >200 mg/dL (non-diabetic)	+1	1
Age >55 years	+1	1
LDH >350 IU/L	+1	1
AST >250 IU/L	+1	1
WBC >16,000/mm³	+1	1
At 48 Hours (C-HOBBS)
Calcium <8 mg/dL	+1	1
Hematocrit drop >10%	+1	1
Oxygen PaO₂ <60 mmHg	+1	1
BUN increase >5 mg/dL	+1	1
Base deficit >4 mEq/L	+1	1
Sequestered fluid >6 L estimated	+1	1
Ranson's Score	/ 11

Interpretation
Score	Predicted Mortality	Recommendation
0–2	~2%	Mild pancreatitis. Likely suitable for ward admission.
3–4	~15%	Moderate pancreatitis. Consider ICU or step-down monitoring.
5–6	~40%	Severe pancreatitis. ICU admission recommended.
≥7	~100%	Very severe. Critical illness, nearly certain mortality without intervention.

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MELD Score

MELD Score (Model for End-Stage Liver Disease)

Parameter	Value
Creatinine (mg/dL) — capped at 4.0
Bilirubin (mg/dL)
INR
On Dialysis (2× in past week or CVVHD)	1 No   Yes (Cr set to 4.0)
MELD Score

Interpretation — 3-Month Mortality
<10	~2% mortality.
10–19	~6% mortality.
20–29	~20% mortality.
30–39	~53% mortality.
≥40	~71% mortality. Consider transplant evaluation.

References

Kamath PS, Wiesner RH, Malinchoc M, et al. A model to predict survival in patients with end-stage liver disease. Hepatology. 2001;33(2):464-470. PMID 11172350. Wiesner R, Edwards E, Freeman R, et al. Model for end-stage liver disease (MELD) and allocation of donor livers. Gastroenterology. 2003;124(1):91-96. PMID 12512033. Formula: MELD = 10 × [0.957 × ln(Cr) + 0.378 × ln(Bilirubin) + 1.120 × ln(INR) + 0.643]. Minimum lab values set to 1.0. Cr capped at 4.0.

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Child-Pugh Score

Child-Pugh Score

Factor	1 Point	2 Points	3 Points
Bilirubin (mg/dL)	1 <2	2–3	>3
Albumin (g/dL)	1 >3.5	2.8–3.5	<2.8
INR	1 <1.7	1.7–2.3	>2.3
Ascites	1 None	Mild/controlled	Moderate-severe
Encephalopathy	1 None	Grade I–II	Grade III–IV
Child-Pugh Score	/ 15

Interpretation
Class	Score	1-Year Survival
A | 5–6 | ~100%
B | 7–9 | ~80%
C | 10–15 | ~45%

References
Pugh RN, Murray-Lyon IM, Dawson JL, et al. Transection of the oesophagus for bleeding oesophageal varices. Br J Surg. 1973;60(8):646-649. PMID 4541913. Durand F, Valla D. Assessment of the prognosis of cirrhosis: Child-Pugh versus MELD. J Hepatol. 2005;42(Suppl 1):S100-107. PMID 15777564.

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Toxicology / Withdrawal

CIWA-Ar Score

CIWA-Ar Score

Category	Select Score
Nausea/Vomiting	1 None (0)   Mild nausea (1)   Intermittent nausea (4)   Constant nausea/dry heaves/vomiting (7)
Tremor (arms extended, fingers spread)	1 None (0)   Not visible, can be felt (1)   Moderate (4)   Severe (7)
Paroxysmal Sweats	1 None (0)   Barely perceptible (1)   Obvious beads of sweat (4)   Drenching sweats (7)
Anxiety	1 None (0)   Mildly anxious (1)   Moderately anxious (4)   Acute panic (7)
Agitation	1 Normal activity (0)   Somewhat restless (1)   Moderately fidgety (4)   Constantly thrashes (7)
Tactile Disturbances	1 None (0)   Mild itch/burning/numbness (1)   Moderate hallucinations (4)   Continuous hallucinations (7)
Auditory Disturbances	1 Not present (0)   Mildly harshened (1)   Moderate hallucinations (4)   Continuous hallucinations (7)
Visual Disturbances	1 Not present (0)   Mild sensitivity (1)   Moderate hallucinations (4)   Continuous hallucinations (7)
Headache/Fullness	1 Not present (0)   Very mild (1)   Moderate (4)   Extremely severe (7)
Orientation/Clouding	1 Oriented (0)   Uncertain about date (1)   Date uncertain >2 days (2)   Disoriented (4)
CIWA-Ar Total	/ 67

Interpretation
<10	Mild withdrawal — May not require pharmacotherapy. Monitor with serial CIWA assessments.
10–18	Moderate withdrawal — Consider benzodiazepine treatment (symptom-triggered protocol).
>18	Severe withdrawal — High risk for seizures/delirium tremens. Aggressive benzodiazepine dosing required. Consider ICU admission.

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Syncope

San Francisco Syncope Rule

San Francisco Syncope Rule (CHESS)

Criteria (CHESS)	No	Yes
C — History of CHF	1
H — Hematocrit <30%	1
E — Abnormal ECG (new changes or non-sinus rhythm)	1
S — Shortness of breath	1
S — Systolic BP <90 mmHg at triage	1
Risk Factors	/ 5

Interpretation
0	Low risk — 2% risk of serious outcome at 30 days. Consider discharge with outpatient follow-up.
≥1	Not low risk — Cannot be classified as low risk. Consider further workup or admission.

References

Quinn JV, Stiell IG, McDermott DA, et al. Derivation of the San Francisco Syncope Rule. Ann Emerg Med. 2004;43(2):224-232. PMID 14747812. Quinn JV, Stiell IG, McDermott DA, et al. The San Francisco Syncope Rule vs physician judgment and decision making. Am J Emerg Med. 2005;23:782-786. Note: Sensitivity ~98% for serious outcomes. Some validation studies show lower performance. Use with clinical judgment.

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ENT / Pharyngitis

Centor/McIsaac Score

Modified Centor (McIsaac) Score

Criteria	No (0)	Yes (+1)
Tonsillar exudates or swelling	0	1
Tender/swollen anterior cervical lymph nodes	0	1
Temperature >38°C (100.4°F)	0	1
Absence of cough	0	1
Age modifier (McIsaac modification)
Age 3–14 years	0	1 (+1)
Age 15–44 years	(0 points — default)
Age ≥45 years	0	-1 (−1)
Modified Centor Score	0   / 5

Interpretation & Management
≤0	~1–2.5% strep probability — No testing or antibiotics needed.
1	~5–10% strep probability — No testing or antibiotics needed (optional rapid strep if high clinical suspicion).
2–3	~11–35% strep probability — Rapid strep testing recommended; treat if positive.
4–5	~51–53% strep probability — Consider empiric antibiotics or rapid strep test.

References
Centor RM et al. The diagnosis of strep throat in adults. Med Decis Making. 1981;1:239-246. PMID 6763125. McIsaac WJ et al. A clinical score to reduce unnecessary antibiotic use. CMAJ. 1998;158:75-83. PMID 9475915.

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Renal / Electrolytes / Acid-Base

Anion Gap

Anion Gap Calculator

Parameter	Value
Sodium (Na⁺) mEq/L
Chloride (Cl⁻) mEq/L
Bicarbonate (HCO₃⁻) mEq/L
Albumin (g/dL) — optional, for correction
Results
Anion Gap	mEq/L
Corrected AG (for albumin)	mEq/L
Delta-Delta Ratio (ΔAG / ΔHCO₃)

Interpretation
AG <12	Normal anion gap — Consider non-AG metabolic acidosis (HARDUPS mnemonic).
AG ≥12	Elevated anion gap — Consider MUDPILES: Methanol, Uremia, DKA, Propylene glycol, Isoniazid/Iron, Lactic acidosis, Ethylene glycol, Salicylates.
Delta-Delta Ratio
<1	Concurrent non-AG metabolic acidosis (mixed).
1–2	Pure anion gap metabolic acidosis.
>2	Concurrent metabolic alkalosis (or pre-existing elevated HCO₃).

References
Kraut JA, Madias NE. Serum anion gap: its uses and limitations in clinical medicine. Clin J Am Soc Nephrol. 2007;2:162-174. PMID 17699401. Fenves AZ et al. Increased anion gap metabolic acidosis as a result of 5-oxoproline (pyroglutamic acid). Proc (Bayl Univ Med Cent). 2006;19:364-367.

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Fractional Excretion of Sodium (FENa)

FENa — Fractional Excretion of Sodium

Parameter	Value
Serum Sodium (mEq/L)
Serum Creatinine (mg/dL)
Urine Sodium (mEq/L)
Urine Creatinine (mg/dL)
FENa (%)	%

Interpretation (in setting of oliguria/AKI)
<1%	Pre-renal azotemia — Kidneys are sodium-avid (hypoperfusion, hypovolemia, heart failure, cirrhosis). Consider volume resuscitation.
>2%	Intrinsic renal disease — ATN, AIN, or glomerulonephritis. Kidneys unable to concentrate urine.
1–2%	Indeterminate — May be seen in early ATN or with mixed etiologies. Clinical correlation required.
Important Caveats
FENa is unreliable on diuretics — use FEUrea instead Low FENa (<1%) can be seen in contrast nephropathy, rhabdomyolysis, early obstruction Not validated in CKD patients

References
Espinel CH. The FENa test: use in the differential diagnosis of acute renal failure. JAMA. 1976;236:579-581. PMID 947239. Steiner RW. Interpreting the fractional excretion of sodium. Am J Med. 1984;77:699-702. PMID 6486145.

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Winters' Formula

Winters' Formula — Expected pCO₂

Input	Value
Serum Bicarbonate (HCO₃⁻) mEq/L
Results
Expected pCO₂ (low end)	mmHg
Expected pCO₂ (high end)	mmHg

Interpretation
pCO₂ in expected range	Appropriate respiratory compensation — Pure metabolic acidosis with adequate compensation.
pCO₂ > expected	Concurrent respiratory acidosis — Inadequate compensation; concurrent respiratory acidosis present.
pCO₂ < expected	Concurrent respiratory alkalosis — Overcompensation; concurrent respiratory alkalosis present.

References
Winters RW, et al. Studies of Acid Base Disturbances. J Clin Invest. 1956;35:311-318. Formula: Expected pCO₂ = 1.5 × [HCO₃⁻] + 8 (± 2) Albert MS, Dell RB, Winters RW. Quantitative displacement of acid-base equilibrium in metabolic acidosis. Ann Intern Med. 1967;66(2):312-322.

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Osmolal Gap

Serum Osmolal Gap

Parameter	Value
Measured Serum Osmolality (mOsm/kg)
Sodium (Na⁺) mEq/L
BUN (mg/dL)
Glucose (mg/dL)
Results
Calculated Osmolality	mOsm/kg
Osmolal Gap	mOsm/kg

Interpretation
<10	Normal — No significant unmeasured osmoles detected.
>10	Elevated — Consider toxic alcohol ingestion: methanol, ethylene glycol, isopropanol, or other unmeasured osmoles (ethanol, mannitol, contrast dye).

References
Smithline N, Gardner KD Jr. Gaps—anionic and osmolal. JAMA. 1976;236(14):1594-1597. PMID 989116. Kraut JA, Xing SX. Approach to the evaluation of a patient with an increased serum osmolal gap and high-anion-gap metabolic acidosis. Am J Kidney Dis. 2011;58(3):480-484. PMID 21794966. Formula: Calculated Osm = 2(Na) + BUN/2.8 + Glucose/18. Gap = Measured − Calculated.

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Corrected Sodium

Corrected Sodium for Hyperglycemia

Parameter	Value
Measured Sodium (mEq/L)
Serum Glucose (mg/dL)
Results
Corrected Na⁺ (Katz, 1.6 mEq per 100 mg/dL)	mEq/L
Corrected Na⁺ (Hillier, 2.4 mEq per 100 mg/dL)	mEq/L

References

Katz MA. Hyperglycemia-induced hyponatremia — calculation of expected serum sodium depression. N Engl J Med. 1973;289(16):843-844. PMID 4763428. Hillier TA, Abbott RD, Barrett EJ. Hyponatremia: evaluating the correction factor for hyperglycemia. Am J Med. 1999;106(4):399-403. PMID 10225241. Classic formula (Katz): Corrected Na = Measured Na + 1.6 × (Glucose − 100) / 100 Revised formula (Hillier): Corrected Na = Measured Na + 2.4 × (Glucose − 100) / 100 (preferred when glucose >400)

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Creatinine Clearance (Cockcroft-Gault)

Creatinine Clearance (Cockcroft-Gault)

Parameter	Value
Age (years)
Sex	1 Male   Female
Weight (kg)
Serum Creatinine (mg/dL)
CrCl (mL/min)	mL/min

Interpretation
>90	Normal renal function.
60–89	Mildly decreased (CKD Stage 2).
30–59	Moderately decreased (CKD Stage 3). Adjust renally-dosed medications.
15–29	Severely decreased (CKD Stage 4).
<15	Kidney failure (CKD Stage 5). Consider dialysis.

References
Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron. 1976;16(1):31-41. PMID 1244564. Formula: CrCl = [(140 − age) × weight (kg)] / [72 × serum Cr (mg/dL)] × 0.85 if female. Note: Use IBW or adjusted BW in obese patients. Not validated in AKI or rapidly changing creatinine.

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Sodium Deficit

Sodium Deficit / Free Water Deficit

Parameter	Value
Sex	1 Male (TBW = 0.6)   Female (TBW = 0.5)
Weight (kg)
Current Sodium (mEq/L)
Desired Sodium (mEq/L)
Results
Total Body Water (L)	L
Sodium Deficit (mEq)	mEq
Free Water Deficit (L) — for hypernatremia	L

References
Adrogué HJ, Madias NE. Hyponatremia. N Engl J Med. 2000;342(21):1581-1589. PMID 10824078. Adrogué HJ, Madias NE. Hypernatremia. N Engl J Med. 2000;342(20):1493-1499. PMID 10816188. Correction rate: Do not exceed 8-10 mEq/L per 24 hours for hyponatremia to avoid osmotic demyelination syndrome.

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Orthopedic / Trauma

Ottawa Ankle Rules

Ottawa Ankle Rule

Criteria	No (0)	Yes (+1)
Ankle X-ray is required if there is pain in the malleolar zone AND any of the following:
Bone tenderness along distal 6 cm of posterior edge of tibia or tip of medial malleolus	1
Bone tenderness along distal 6 cm of posterior edge of fibula or tip of lateral malleolus	1
Inability to bear weight both immediately and in the ED (4 steps)	1
Foot X-ray is required if there is pain in the midfoot zone AND any of the following:
Bone tenderness at the base of the 5th metatarsal	1
Bone tenderness at the navicular	1
Inability to bear weight both immediately and in the ED (4 steps)	1
Positive Criteria	/ 6

Interpretation
Score = 0	No X-ray needed — Sensitivity 96.4–99.6% for clinically significant fractures.
Score ≥ 1	X-ray recommended — Ankle and/or foot x-ray indicated based on positive criteria location.

References
Stiell IG et al. A study to develop clinical decision rules for radiography in acute ankle injuries. Ann Emerg Med. 1992;21:384-390. PMID 1554175. Stiell IG et al. Decision rules for radiography in acute ankle injuries: refinement and prospective validation. JAMA. 1993;269:1127-1132. PMID 8433468.

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Ottawa Knee Rules

Ottawa Knee Rule

Criteria	No (0)	Yes (+1)
Age ≥55 years	1
Tenderness at head of fibula	1
Isolated tenderness of patella (no other knee bone tenderness)	1
Inability to flex to 90°	1
Inability to bear weight (4 steps both immediately and in ED)	1
Criteria Met	/ 5

Interpretation
0	X-ray NOT indicated — No Ottawa Knee Rule criteria met. Sensitivity 98.5% for fracture.
≥1	X-ray indicated — One or more criteria met; obtain knee radiographs to evaluate for fracture.

References
Stiell IG et al. Prospective validation of a decision rule for radiography in acute knee injuries. JAMA. 1996;275:611-615. PMID 8594242. Stiell IG et al. Implementation of the Ottawa Knee Rule. JAMA. 1997;278:2075-2079. PMID 9403421.

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NEXUS Criteria

NEXUS Criteria for C-Spine Imaging

Criteria (ALL must be absent to clear)	Absent	Present
Posterior midline cervical tenderness	1
Focal neurologic deficit	1
Altered level of alertness	1
Intoxication	1
Distracting painful injury	1
Criteria Present	/ 5

Interpretation
0	C-spine can be cleared clinically — All 5 criteria absent. No imaging needed. Sensitivity 99.6% for clinically significant injury.
≥1	Cannot clear clinically — C-spine imaging indicated.

References
Hoffman JR, Mower WR, Wolfson AB, et al. Validity of a set of clinical criteria to rule out injury to the cervical spine in patients with blunt trauma (NEXUS). N Engl J Med. 2000;343(2):94-99. PMID 10891516.

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Canadian C-Spine Rule

Canadian C-Spine Rule

Step 1: Any High-Risk Factor? (mandates radiography)
Criteria	No	Yes
Age ≥65	1
Dangerous mechanism (fall ≥1m/5 stairs, axial load to head, MVC >100km/h or rollover/ejection, motorized recreational vehicle, bicycle collision)	1
Paresthesias in extremities	1
Step 2: Any Low-Risk Factor? (allows safe ROM assessment)
Simple rear-end MVC (excludes: pushed into traffic, hit by bus/large truck, rollover, hit by high-speed vehicle)	1
Sitting position in ED	1
Ambulatory at any time since injury	1
Delayed onset of neck pain (not immediate)	1
Absence of midline cervical tenderness	1
Step 3: Able to actively rotate neck 45° left and right?
Can rotate neck 45° L and R	1
High Risk Factors	/ 3
Low Risk Factors	/ 5

Interpretation (stepwise)
High risk ≥1	Radiography indicated — Do NOT assess ROM. Image the c-spine.
Low risk = 0	Cannot assess ROM safely — No low-risk factor present to allow safe assessment. Image.
Low risk ≥1 + ROM OK	C-spine can be cleared — At least one low-risk factor AND able to rotate neck 45°. No imaging needed.
Low risk ≥1 + no ROM	Radiography indicated — Low-risk factor present but unable to rotate. Image.

References
Stiell IG, Wells GA, Vandemheen KL, et al. The Canadian C-Spine Rule for radiography in alert and stable trauma patients. JAMA. 2001;286(15):1841-1848. PMID 11597285. Stiell IG, Clement CM, McKnight RD, et al. The Canadian C-Spine Rule versus the NEXUS low-risk criteria in patients with trauma. N Engl J Med. 2003;349(26):2510-2518. PMID 14695411.

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Parkland Formula

Parkland Formula — Burn Fluid Resuscitation

Parameter	Value
Patient Weight (kg)
TBSA Burned (%)
Results (Lactated Ringer's)
Total 24-hour volume	mL
First 8 hours (½ of total)	mL
Rate for first 8 hours	mL/hr
Next 16 hours (½ of total)	mL
Rate for next 16 hours	mL/hr

Notes
Formula: 4 mL × body weight (kg) × %TBSA burned = total fluid for first 24 hours Give first half over the first 8 hours from time of burn (not from time of presentation) Give second half over the next 16 hours Use Lactated Ringer's solution Titrate to urine output: 0.5–1 mL/kg/hr in adults; 1 mL/kg/hr in children This is a starting point — adjust based on clinical response

References
Baxter CR, Shires T. Physiological response to crystalloid resuscitation of severe burns. Ann N Y Acad Sci. 1968;150:874-894. PMID 4973463. Saffle JI. The phenomenon of fluid creep in acute burn resuscitation. J Burn Care Res. 2007;28:382-395. PMID 17438489.

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Pediatrics

PECARN Pediatric Head Injury

PECARN — Pediatric Head CT Decision Rule

Age Group	Select One
Patient Age	1 <2 years    ≥2 years

Age <2 Years — Risk Factors

Criteria	No	Yes
GCS <15 (altered mental status)	1
Palpable skull fracture	1
Occipital/parietal/temporal scalp hematoma	1
Loss of consciousness ≥5 seconds	1
Not acting normally per parent	1
Severe mechanism of injury (MVC with ejection/rollover/fatality, pedestrian/cyclist without helmet struck by motorized vehicle, fall >3 feet, head struck by high-impact object)	1
Risk Factors (<2y)	/ 6

Age ≥2 Years — Risk Factors

Criteria	No	Yes
GCS <15 (altered mental status)	1
Signs of basilar skull fracture (hemotympanum, raccoon eyes, Battle sign, CSF otorrhea/rhinorrhea)	1
Vomiting	1
Loss of consciousness	1
Severe headache	1
Severe mechanism of injury (MVC with ejection/rollover/fatality, pedestrian/cyclist without helmet struck by motorized vehicle, fall >5 feet, head struck by high-impact object)	1
Risk Factors (≥2y)	/ 6

Interpretation (for selected age group)
0	Very low risk — ciTBI risk <0.02% (<2y) or <0.05% (≥2y). CT not recommended.
1 (intermediate*)	Low risk — ciTBI risk ~0.9% (<2y) or ~0.8% (≥2y). Observation vs. CT. *Only if GCS=15 and no skull fracture/AMS. Consider observation for 4-6 hours.
GCS<15 or skull fx	High risk — ciTBI risk 4.4% (<2y) or 4.3% (≥2y). CT recommended.

References
Kuppermann N, Holmes JF, Dayan PS, et al. Identification of children at very low risk of clinically-important brain injuries after head trauma: a prospective cohort study. Lancet. 2009;374:1160-1170. PMID 19758692.

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APGAR Score

APGAR Score

Criteria	0	1	2
Appearance (Color)	1 Blue/pale all over	Blue extremities, pink body	Pink all over
Pulse (Heart Rate)	1 Absent	<100 bpm	≥100 bpm
Grimace (Reflex Irritability)	1 No response	Grimace/weak cry	Cry or pull away
Activity (Muscle Tone)	1 Limp	Some flexion	Active motion
Respiration	1 Absent	Slow/irregular	Good cry
APGAR Score	/ 10

Interpretation
0–3	Critically low — Immediate resuscitation needed.
4–6	Moderately low — May require some resuscitative measures.
7–10	Reassuring — Routine neonatal care.

References
Apgar V. A proposal for a new method of evaluation of the newborn infant. Curr Res Anesth Analg. 1953;32(4):260-267. American Academy of Pediatrics Committee on Fetus and Newborn. The Apgar Score. Pediatrics. 2015;136(4):819-822. PMID 26416932.

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Anthropometrics / Dosing

BMI / Body Surface Area

BMI & Body Surface Area

Parameter	Value
Weight (kg)
Height (cm)
Results
BMI (kg/m²)	kg/m²
BSA (Mosteller, m²)	m²

BMI Classification (WHO)
<18.5 | Underweight
18.5–24.9 | Normal weight
25–29.9 | Overweight
30–34.9 | Obesity class I
35–39.9 | Obesity class II
≥40 | Obesity class III (morbid)

References
WHO. Obesity: preventing and managing the global epidemic. WHO Technical Report Series 894. Geneva, 2000. Mosteller RD. Simplified calculation of body-surface area. N Engl J Med. 1987;317(17):1098. PMID 3657876. BMI = weight (kg) / height² (m²). BSA (Mosteller) = √(height(cm) × weight(kg) / 3600).

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Ideal Body Weight

Ideal Body Weight / Adjusted Body Weight

Parameter	Value
Sex	1 Male   Female
Height (inches) — total inches, e.g. 70 for 5'10"
Actual Weight (kg) — for adjusted BW
Results
Ideal Body Weight (Devine)	kg
Adjusted Body Weight (IBW + 0.4 × [ABW − IBW])	kg

References
Devine BJ. Gentamicin therapy. Drug Intell Clin Pharm. 1974;8:650-655. Male IBW = 50 kg + 2.3 kg per inch over 5 feet. Female IBW = 45.5 kg + 2.3 kg per inch over 5 feet. Adjusted BW = IBW + 0.4 × (Actual BW − IBW). Used for drug dosing in obese patients (e.g., vancomycin, aminoglycosides). Tidal volume dosing: Use IBW for ventilator settings (6–8 mL/kg IBW per ARDSNet protocol).

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Maintenance Fluids (4-2-1 Rule)

Maintenance IV Fluids (4-2-1 Rule)

Parameter	Value
Patient Weight (kg)
Maintenance Rate
Hourly Rate	mL/hr
Daily Volume	mL/day

References
Holliday MA, Segar WE. The maintenance need for water in parenteral fluid therapy. Pediatrics. 1957;19(5):823-832. PMID 13431307. 4-2-1 Rule: 4 mL/kg/hr for first 10 kg + 2 mL/kg/hr for next 10 kg + 1 mL/kg/hr for each kg above 20 kg.

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Schwartz Equation (Pediatric GFR)

Schwartz Equation — Pediatric eGFR

Parameter	Value
Height (cm)
Serum Creatinine (mg/dL)
Estimated GFR	mL/min/1.73m²

References
Schwartz GJ, Muñoz A, Schneider MF, et al. New equations to estimate GFR in children with CKD. J Am Soc Nephrol. 2009;20(3):629-637. PMID 19158356. Bedside Schwartz (2009): eGFR = 0.413 × height (cm) / serum creatinine (mg/dL). Valid for ages 1-16 years.

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Disclaimer: These calculators are provided as clinical decision support tools only. They do not replace clinical judgment. Always consider the full clinical picture when making treatment decisions. Scoring systems referenced from peer-reviewed literature. See individual template pages for complete references.