Clinical calculators for the wards.

No — Cockcroft-Gault estimates creatinine clearance, while eGFR (CKD-EPI) estimates true glomerular filtration rate. CrCl is still widely used for renal drug dosing since many drug labels reference it directly.

No — Cockcroft-Gault assumes stable renal function and isn't valid once a patient is on dialysis.

Some drugs, especially chemotherapy agents, are dosed per unit of body surface area rather than weight alone, since it correlates better with metabolic rate and clearance for those agents.

No — DuBois and Haycock formulas also exist. Mosteller is widely used because it's simple and performs comparably well.

No — it doesn't distinguish muscle from fat, so it can be misleading in very muscular individuals. It's a screening tool, not a diagnosis.

Some guidelines use lower overweight/obesity cutoffs for certain ethnic groups due to differing cardiometabolic risk at the same BMI.

Most modern teaching omits potassium for simplicity, giving a normal range of about 8-12 mEq/L. Including potassium shifts the normal range slightly higher.

MUDPILES: methanol, uremia, DKA, propylene glycol, isoniazid/iron, lactic acidosis, ethylene glycol, salicylates.

No — corrected calcium is a formula-based estimate, while ionized calcium is a direct lab measurement of the active fraction. Ionized calcium is more accurate when available.

The correction becomes less reliable at extremes of albumin — interpret cautiously in severe hypoalbuminemia and consider an ionized calcium level instead.

No — it doesn't apply to valvular AF (rheumatic mitral stenosis or mechanical heart valves), which has its own anticoagulation approach.

A score of 0 generally means anticoagulation isn't recommended, though individual risk factors should still be considered.

It informs the decision but shouldn't be used alone — many guidelines now recommend urgent specialist TIA clinic assessment and imaging regardless of score, given known limitations of ABCD2's predictive accuracy.

It's still commonly taught and referenced, but several health systems have moved toward urgent universal TIA-clinic pathways rather than relying on ABCD2 alone to triage risk.

It was developed and validated specifically in ICU populations. For ward-based screening, qSOFA is the simpler, lab-free alternative.

Track the trend — an increasing SOFA score over the first 48 hours is more predictive of mortality than any single value.

A low score at 1 minute is common and often improves by 5 minutes. The 5-minute score and trend are more predictive than the 1-minute score alone.

It's a snapshot of immediate transition to extrauterine life, not a strong predictor of long-term neurological outcome on its own.

It's primarily used in pediatrics. Adult maintenance fluid calculations use other weight-based approaches and are adjusted more heavily for clinical context.

Adjust upward for fever or ongoing losses, and downward in fluid-overload states like heart failure or renal failure.

No — pack-years measures cumulative exposure only. Time since quitting is considered separately when applying screening criteria.

One pack is defined as 20 cigarettes, which is the standard used in the pack-years formula.

No — it's a screening tool to help decide which confirmatory test to order next (iron studies vs. hemoglobin electrophoresis), not a diagnostic test itself.

No — the Mentzer Index is only meaningful in the context of microcytic anemia (low MCV). It wasn't designed for normocytic or macrocytic anemia.

Any positive response to item 9 warrants direct assessment of suicide risk, regardless of the total score — it should never be dismissed just because the overall score is mild.

No — it's a screening and severity-tracking tool. Diagnosis requires full clinical assessment against diagnostic criteria.

No — it's a screening and severity-tracking tool, not a diagnostic instrument on its own.

Yes — they're commonly used together since anxiety and depression frequently co-occur, and each captures a different symptom domain.

No — it assumes a regular 28-day cycle with ovulation on day 14. Early ultrasound dating is generally more accurate, especially with irregular cycles.

If a first-trimester ultrasound dating differs significantly from LMP dating, ultrasound dating is typically used to set the official EDD.

A score below 6 suggests an unfavorable cervix, where cervical ripening agents are often considered before induction to improve the chance of success.

It's mainly used to predict the likelihood of successful induction, not to manage spontaneous labor that's already established.

Toxic alcohols (methanol, ethylene glycol, isopropyl alcohol), mannitol, and severe ketoacidosis are common causes of an elevated, unexplained osmolar gap.

No — a normal gap doesn't fully exclude it, especially later after ingestion once the alcohol has been metabolized. Clinical suspicion still matters.

No — a low score makes appendicitis less likely but doesn't fully exclude it. Clinical judgment and, often, imaging are still used alongside the score.

Its performance varies somewhat by age and sex (it tends to perform less well in women and young children), so use it as one input rather than a stand-alone diagnostic tool.

It correlates with perioperative risk but reflects baseline health, not the risk of the specific procedure — it's typically combined with procedure-specific risk factors for a fuller picture.

Yes — an "E" suffix (e.g. ASA IIIE) denotes an emergency operation, which is associated with higher risk than the same class in a non-emergency setting.

A score of 0 is associated with very low risk, and such patients are sometimes considered for outpatient management rather than admission, per local protocol.

The validated score was derived using mmol/L. If your lab reports BUN in mg/dL, convert by dividing by approximately 2.8 to get urea in mmol/L.

CAM is positive (delirium likely) when features 1 and 2 are both present, AND either feature 3 or feature 4 is also present.

No — it screens for the presence of delirium itself. Identifying the underlying cause requires separate clinical workup.