Siemens Atellica CH/IM + Roche Cobas Clinical Chemistry & Hormone Interpreter v2.0. Trigger for any chemistry or hormone panel result interpretation. Covers renal, liver, electrolytes, metabolic, iron, thyroid (TSH/FT3/FT4), adrenal (cortisol/ ACTH/aldosterone), reproductive & fertility hormones (LH/FSH/E2/progesterone/ testosterone/prolactin/AMH), cardiac function (hs-troponin/BNP/NT-proBNP/CK/ CK-MB/myoglobin/D-Dimer), bone health (PTH/Vitamin D/P1NP/CTX/osteocalcin), haematinics (vitamin B12/folate/RBC folate/homocysteine/MMA/holotranscobalamin), inflammatory markers, lipids, and tumour markers. Critical value flagging → parameter table → organ system assessment → differential diagnosis → action plan. Always asks for missing age, sex, cycle day, sample time, fasting status.
Version: 2.0 | Updated: April 2026 Standards: IFCC · CLSI · ISO 15189:2022 · JCAHO NPSG.02.03.01 · CBAHI · SFDA · ESC 2023 · Endocrine Society · IOF · NICE Brand: EEHLSS / MedLabAI-LIS | Crimson #B71C1C · Navy #0D1B4B · Gold #F9A825
Ask for anything missing before interpreting.
Required:
Always ask if not provided (hormone-specific):
Unit conversions: Cortisol: nmol/L ÷ 27.6 = µg/dL | Vitamin D: nmol/L ÷ 2.496 = ng/mL | B12: pmol/L × 1.355 = pg/mL | Folate: nmol/L × 0.441 = ng/mL | T4: nmol/L × 0.078 = µg/dL
(Apply silently; reference when explaining unexpected results)
| Technology | Key Analytes | Principle |
|---|---|---|
| Photometry (endpoint/kinetic) | LFTs, glucose, creatinine, urea, uric acid, cholesterol, TG, CK, LDH, ALP, bilirubin | Chromogenic reaction; absorbance at specific λ |
| Turbidimetry / PETINIA | CRP, hs-CRP, immunoglobulins, transferrin, HbA1c (turbidimetric inhibition), RF | Immune complex light scatter |
| IMT (Ion-Selective Electrode) | Na⁺, K⁺, Cl⁻ | Indirect ISE; automated calibration |
| Enzymatic colorimetric | Fe, TIBC, Mg, phosphate, calcium, enzymatic creatinine | Direct enzymatic colour reactions |
| EMIT | TDM (cyclosporin, tacrolimus), drugs of abuse | Competitive homogeneous immunoassay |
| Sandwich (large molecules) | TSH, LH, FSH, prolactin, insulin, PTH(intact), NT-proBNP, BNP, hs-TnI, AFP, CEA, CA-125, CA19-9, PSA, ferritin, B12, folate |
|---|---|
| Competitive (small molecules) | FT4, FT3, cortisol, testosterone, estradiol, progesterone, DHEA-S, 25-OH Vit D, ACTH, aldosterone, Total T4, Total T3 |
| Acridinium ester label | All IM assays — photon emission on oxidation; photomultiplier detection |
| Interferent | Analytes Affected | Effect | Action |
|---|---|---|---|
| Haemolysis (H) | K⁺, AST, LDH, cortisol (some methods) | K⁺/AST falsely elevated | Reject if H>2+; request fresh sample |
| Lipaemia (L) | Most photometric assays | Turbidity elevates absorbance | Ultracentrifuge; blanking methods |
| Icterus (I) | ALT, AST, albumin, Jaffé creatinine | Bilirubin absorbs at reaction wavelength | Enzymatic creatinine; note if I>2+ |
| Biotin (>5mg/day) | TSH (↓), FT4 (↑), troponin, 25-OH Vit D, folate, B12, PTH, prolactin, LH, FSH, hCG | Streptavidin competition — signals disrupted | 24h washout; repeat |
| Heterophile antibodies (HAMA) | Any sandwich assay: TSH, troponin, PSA, prolactin, BNP | False positive or negative | Dilution series; blocking tubes; alternate platform |
| Macro-prolactin | Prolactin | Spuriously elevated (IgG-PRL complex) | PEG precipitation; <40% recovery = macro-PRL (benign) |
| High B12 interference | Folate (competitive binding assay) | Falsely normal folate if B12 very high | Use RBC folate for definitive stores |
| Analyte | Male | Female | Units | Critical Low | Critical High |
|---|---|---|---|---|---|
| Creatinine | 62–106 | 44–80 | µmol/L | <27 | >884 🚨 |
| eGFR (CKD-EPI) | ≥90 = normal | ≥90 = normal | mL/min/1.73m² | — | — |
| Urea | 2.5–7.1 | 2.5–7.1 | mmol/L | — | >35.7 🚨 |
| Uric acid | 202–416 | 143–339 | µmol/L | — | >595 |
| Na⁺ | 136–145 | 136–145 | mmol/L | <120 🚨 | >158 🚨 |
| K⁺ | 3.5–5.1 | 3.5–5.1 | mmol/L | <2.8 🚨 | >6.2 🚨 |
| Cl⁻ | 98–107 | 98–107 | mmol/L | <70 🚨 | >120 🚨 |
| HCO₃⁻ | 22–29 | 22–29 | mmol/L | <10 🚨 | >40 🚨 |
| Phosphate | 0.87–1.45 | 0.87–1.45 | mmol/L | <0.3 🚨 | >2.9 |
| Magnesium | 0.66–1.07 | 0.66–1.07 | mmol/L | <0.4 🚨 | >2.1 🚨 |
CKD Staging (KDIGO 2022): G1 ≥90 (normal) · G2 60–89 (mildly reduced) · G3a 45–59 (mildly-moderately reduced — nephrology review) · G3b 30–44 (moderately-severely reduced — nephrology essential) · G4 15–29 (severely reduced — RRT planning) · G5 <15 (kidney failure — dialysis/transplant)
AKI definition: Cr rise >26.5 µmol/L in 48h OR >1.5× baseline within 7 days Urea:Cr ratio (both mmol/L): >100 = pre-renal · 50–100 = indeterminate · <50 = intrinsic
| Analyte | Male | Female | Units | Critical High |
|---|---|---|---|---|
| Total Bilirubin | 3.4–17.1 | 3.4–17.1 | µmol/L | >342 🚨 |
| Direct Bilirubin | 0–5 | 0–5 | µmol/L | >170 🚨 |
| Indirect Bilirubin | 3.4–12 | 3.4–12 | µmol/L | — |
| AST | 10–40 | 10–35 | U/L | >1000 🚨 |
| ALT | 7–56 | 7–45 | U/L | >1000 🚨 |
| ALP | 44–147 | 35–104 | U/L | >1500 |
| GGT | 8–61 | 5–36 | U/L | >300 |
| Total Protein | 60–83 | 60–83 | g/L | <40 🚨 |
| Albumin | 35–52 | 35–52 | g/L | <20 🚨 |
| LDH | 135–225 | 135–214 | U/L | — |
| Ammonia | 9–33 | 9–33 | µmol/L | >55 🚨 |
Liver Injury Patterns:
| Pattern | ALT | AST | ALP | GGT | Bilirubin | Cause |
|---|---|---|---|---|---|---|
| Hepatocellular | ↑↑↑ | ↑↑↑ | N/↑ | ↑ | Variable | Viral hepatitis, NAFLD, alcohol, drugs, ischaemia |
| Cholestatic | N/↑ | N/↑ | ↑↑↑ | ↑↑↑ | ↑↑ direct | Biliary obstruction, PBC, PSC, drug-induced |
| Mixed | ↑↑ | ↑↑ | ↑↑ | ↑↑ | ↑ | Drug reaction, infiltrative, pregnancy |
| Synthetic failure | N/↓ | N | N/↑ | ↑ | ↑ direct | Cirrhosis, ALF — check INR + albumin urgently |
| Isolated ↑GGT | N | N | N | ↑↑ | N | Alcohol, enzyme induction, fatty liver |
| ↑ALP + normal GGT | N | N | ↑↑ | N | N | Bone origin — check BSALP/P1NP |
| AST:ALT >2:1 | ↑ | ↑↑ | ↑ | ↑↑↑ | Var | Alcoholic hepatitis (de Ritis); also check CK |
R-ratio: (ALT÷ALT_ULN) ÷ (ALP÷ALP_ULN) — ≥5=hepatocellular · 2–5=mixed · ≤2=cholestatic Synthetic failure markers: Albumin <28 + Bilirubin >51 + INR >1.5 = decompensated → urgent hepatology referral
| Analyte | Reference | Units | Critical |
|---|---|---|---|
| Fasting glucose | 3.9–5.6 | mmol/L | <2.2 🚨 / >27.8 🚨 |
| Random glucose | <7.8 | mmol/L | <2.2 🚨 / >27.8 🚨 |
| HbA1c | <42 normal; 42–47 prediabetes; ≥48 diabetes | mmol/mol | — |
| HbA1c (%) | <6.0% normal; 6.0–6.4% prediabetes; ≥6.5% diabetes | % | — |
| Insulin (fasting) | 17.8–173 | pmol/L | — |
| C-peptide | 0.37–1.47 | nmol/L | — |
| Total Cholesterol | <5.2 desirable | mmol/L | >13 |
| LDL-C | <3.4 desirable; <2.6 moderate CV risk; <1.8 high CV risk; <1.4 very high | mmol/L | — |
| HDL-C | M:>1.0; F:>1.2 | mmol/L | <0.75 🚨 |
| Triglycerides (fasting) | <1.7 normal; >5.6 very high; >11.3 pancreatitis | mmol/L | >11.3 🚨 |
| Apolipoprotein B (ApoB) | M:<1.0; F:<0.9 optimal | g/L | >1.4 = high atherogenic risk |
| Apolipoprotein A1 | M:1.0–1.6; F:1.0–1.9 | g/L | <0.9 = low HDL capacity |
| Lipoprotein(a) [Lp(a)] | <125 nmol/L (<50 mg/dL) | nmol/L | >125 = high independent CV risk |
HbA1c Note: Unreliable in haemolytic anaemia, haemoglobinopathies, recent transfusion, severe IDA. Use fructosamine or plasma glucose average instead. In thalassaemia/HbE: use Bio-Rad HPLC or boronate affinity method.
| Analyte | Male | Female | Units |
|---|---|---|---|
| Serum Iron | 9.0–30.4 | 7.2–25.9 | µmol/L |
| TIBC | 44.8–76.1 | 44.8–76.1 | µmol/L |
| Transferrin Saturation | 20–50% | 15–45% | % |
| Ferritin | 30–300 | 15–200 | µg/L |
| Transferrin | 2.0–3.6 | 2.0–3.6 | g/L |
| sTfR | 2.2–5.0 | 1.9–4.4 | mg/L |
Iron Pattern Table: IDA: ↓↓Ferritin + ↓↓Fe + ↑↑TIBC + ↓↓Trf Sat (<16%) | ACD: ↑/N Ferritin + ↓Fe + ↓/N TIBC + low-normal Trf Sat | Haemochromatosis: ↑↑↑Ferritin + ↑↑Fe + ↓TIBC + ↑↑Trf Sat (>45%) | Haemolysis: ↑/N Ferritin + ↑Fe + N TIBC + ↑Trf Sat
| Analyte | Reference | Units | Critical Low | Critical High |
|---|---|---|---|---|
| TSH (3rd/4th gen) | 0.27–4.20 | mIU/L | <0.03 🚨 | >100 🚨 |
| Free T4 (FT4) | 12–22 | pmol/L | <6 🚨 | >77 🚨 |
| Free T3 (FT3) | 3.1–6.8 | pmol/L | <2.0 | >20 🚨 |
| Total T4 | 66–181 | nmol/L | — | — |
| Total T3 | 1.3–3.1 | nmol/L | — | — |
| Reverse T3 (rT3) | 0.14–0.54 | nmol/L | — | — |
| Anti-TPO | <34 | IU/mL | — | >500 (significant autoimmune) |
| Anti-thyroglobulin | <115 | IU/mL | — | — |
| TSH receptor Ab (TRAb) | <1.75 | IU/L | — | >10 (active Graves') |
| Thyroglobulin | <10 (euthyroid); <1 post-thyroidectomy | µg/L | — | — |
TSH Algorithm:
| TSH | FT4 | FT3 | Interpretation | Action |
|---|---|---|---|---|
| Low | High | High | Primary hyperthyroidism — overt | TRAb; thyroid USS; refer endocrinology |
| Low | Normal | Normal-high | Subclinical hyperthyroidism OR NTI/drugs | Repeat 3m; exclude amiodarone/steroids |
| Low | Low | Low | Central hypothyroidism | MRI pituitary; assess all pituitary axes |
| High | Low | Low | Primary hypothyroidism — overt | Anti-TPO; start levothyroxine |
| High | Normal | Normal | Subclinical hypothyroidism | Anti-TPO; treat if TSH>10 or symptomatic/pregnant |
| Normal | Low | Low | Non-thyroidal illness (NTI) / sick euthyroid | Repeat when clinically recovered |
| Normal | High | High | Thyroid hormone resistance OR assay interference | Biotin check; heterophile Ab test |
Pregnancy Thyroid Ranges:
| Trimester | TSH (mIU/L) | FT4 (pmol/L) |
|---|---|---|
| 1st (0–12w) | 0.1–2.5 | 12–19 |
| 2nd (13–26w) | 0.2–3.0 | 10–16 |
| 3rd (27–40w) | 0.3–3.5 | 8–14 |
Drug Effects on TFTs: Amiodarone: ↑T4 + ↓T3 (inhibits conversion) | Steroids: ↓TSH | Heparin: falsely ↑FT4 (displaces from TBG) | Oestrogens: ↑TBG → ↑Total T4/T3, FT4 normal | Lithium: hypothyroidism risk | Phenytoin: ↓total T4 (displaces TBG) | Metformin: modest ↓TSH
| Analyte | Reference | Units | Critical |
|---|---|---|---|
| Cortisol (08:00–09:00) | 171–536 | nmol/L | <83 (adrenal crisis risk) 🚨 |
| Cortisol (16:00–18:00) | 64–327 | nmol/L | — |
| Cortisol (midnight serum) | <138 | nmol/L | >207 = loss of diurnal rhythm |
| Cortisol (midnight salivary) | <5.3 | nmol/L | >5.3 = Cushing's screen positive |
| Post-1mg DST (08:00) | <50 nmol/L = normal suppression | nmol/L | >50 = screen positive for Cushing's |
| Short Synacthen (30 min peak) | >450 nmol/L = adequate | nmol/L | <450 = adrenal insufficiency |
| ACTH (plasma 08:00–09:00) | 7.2–63.3 pg/mL (1.6–13.9 pmol/L) | pg/mL | — |
| Aldosterone (supine) | 100–500 | pmol/L | — |
| Aldosterone (upright) | 100–800 | pmol/L | — |
| Renin (active, supine) | 5.1–46.1 | mU/L | — |
| Aldosterone:Renin Ratio (ARR) | <750 (pmol/L : mU/L) | — | >750 = primary hyperaldosteronism screen positive |
| DHEA-S (F 18–50y) | 1.3–8.4 | µmol/L | — |
| DHEA-S (M 18–50y) | 2.4–11.7 | µmol/L | — |
| 24h Urine Cortisol (UFC) | <166 | nmol/24h | >3× ULN = Cushing's probable |
| 17-OH Progesterone (basal) | F follicular: <6; M:<7.5 | nmol/L | >30 = CAH screen |
Cortisol/ACTH Interpretation Matrix:
| Cortisol | ACTH | Interpretation | Confirmation |
|---|---|---|---|
| ↓ | ↑↑ | Primary adrenal insufficiency (Addison's) | SST; 21-hydroxylase Ab; adrenal CT |
| ↓ | ↓ or N | Secondary adrenal insufficiency (pituitary) | MRI pituitary; other pituitary hormone axes |
| ↑ | ↓ | ACTH-independent Cushing's (adrenal adenoma/carcinoma) | Adrenal CT/MRI |
| ↑ | ↑ | ACTH-dependent Cushing's (Cushing's disease or ectopic ACTH) | MRI pituitary; CRH test; IPSS |
| Fails to suppress on DST | Variable | Cushing's syndrome screen positive | 48h high-dose DST; UFC; further workup |
Cushing's Screening Algorithm: First-line tests (≥2 needed): (1) 1mg overnight DST — cortisol >50 nmol/L = screen positive; (2) 24h UFC >3× ULN; (3) midnight salivary cortisol >5.3 nmol/L. If screen positive → refer endocrinology for second-line testing.
| Analyte | Follicular | Ovulatory | Luteal | Post-Menopause | Units |
|---|---|---|---|---|---|
| LH | 2.4–12.6 | 14.0–95.6 | 1.0–11.4 | 7.7–58.5 | IU/L |
| FSH | 3.5–12.5 | 4.7–21.5 | 1.7–7.7 | 25.8–134.8 | IU/L |
| Estradiol (E2) | 46–607 | 315–1828 | 161–774 | <201 | pmol/L |
| Progesterone | <3.2 | Variable | 9.5–76.4 | <3.2 | nmol/L |
| Testosterone | 0.3–1.7 | — | — | 0.1–1.4 | nmol/L |
| SHBG | 32.4–128 | — | — | 17–90 | nmol/L |
| Prolactin | 102–496 | — | — | 102–496 | mIU/L |
| DHEA-S | 1.3–8.4 (18–50y) | — | — | 0.3–3.6 | µmol/L |
| AMH | 1.0–3.5 (25–35y); >1.0 good reserve; 0.5–1.0 low-normal; <0.5 poor | — cycle-independent — | ng/mL | ||
| Inhibin B | 23–257 (follicular D2–5) | — | — | <17 | pg/mL |
| Free Androgen Index (FAI) | Total testosterone (nmol/L) × 100 ÷ SHBG (nmol/L); Normal female <5 | ||||
| Beta-hCG | <5 | — | — | <5 | IU/L |
| Analyte | Reference | Units |
|---|---|---|
| LH | 1.7–8.6 | IU/L |
| FSH | 1.5–12.4 | IU/L |
| Total Testosterone (08:00 sample) | 9.9–27.8 | nmol/L |
| Free Testosterone (calculated) | 0.22–0.64 | nmol/L |
| Estradiol (E2) | <146 | pmol/L |
| SHBG | 16.5–55.9 | nmol/L |
| Prolactin | 86–324 | mIU/L |
| Inhibin B | 80–400 | pg/mL |
Reproductive Hormone Interpretation Framework:
| Pattern | Finding | Diagnosis | Action |
|---|---|---|---|
| LH ↑↑ + FSH ↑↑ + E2 ↓↓ (F <40y) | High gonadotrophins + low E2 | Premature Ovarian Insufficiency (POI) | Anti-TPO; chromosomes (fragile X); bone DEXA; HRT |
| LH ↑↑ + FSH ↑↑ (F ≥45y) | Menopausal gonadotrophin levels | Menopause | Clinical assessment; DEXA |
| LH:FSH >2:1 + ↑testosterone + FAI >5 + ↓SHBG | Hyperandrogenism + gonadotrophin imbalance | PCOS | Pelvic USS (AFC); insulin/glucose; lipids |
| FSH ↑ + AMH ↓ + Inhibin B ↓ (reproductive age) | Reduced ovarian reserve | DOR | Fertility specialist; AFC on USS |
| PRL >600 mIU/L | Hyperprolactinaemia | Prolactinoma vs drug-induced vs macro-PRL | PEG precipitation first; then MRI pituitary; medication review |
| LH ↓ + FSH ↓ + E2 ↓ (or T ↓ in male) | Hypogonadotrophic hypogonadism | Secondary hypogonadism — pituitary/hypothalamic | MRI pituitary; assess GH/ACTH/TSH; Kallmann if anosmia |
| Progesterone <30 nmol/L (D21 or D[cycle-7]) | Sub-optimal luteal | Anovulation or luteal phase defect | Prolactin; thyroid; PCOS screen; repeat timing |
| Progesterone ≥30 nmol/L (mid-luteal) | Ovulation confirmed | — | Reassure; if conception issues: semen analysis + tubotomy |
| T ↓ (male) + LH ↓ or N | Secondary hypogonadism | Pituitary pathology / haemochromatosis | MRI pituitary; ferritin; iron sat |
| T ↓ (male) + LH ↑ | Primary testicular failure | Klinefelter's or other | Karyotype; testicular USS; semen analysis |
| Estradiol ↑↑ (male) + normal or ↓ T | Oestrogen excess | Obesity (aromatase excess), liver disease, exogenous oestrogen, oestrogen-secreting tumour | LFTs; testicular USS; BMI |
Ovulation Confirmation: Mid-luteal progesterone ≥30 nmol/L confirms ovulation. Sample at day (cycle length − 7). For 28-day cycle = Day 21. Borderline 15–30 nmol/L: repeat sample; timing may be off.
OCP/HRT Effects: Oestrogen-containing OCP: suppresses LH/FSH (near zero) + raises SHBG. Should be discontinued ≥4–6 weeks before gonadal hormone assessment ideally.
| Analyte | Male | Female | Units | Critical |
|---|---|---|---|---|
| hs-Troponin I (Atellica) | <34 | <16 | ng/L | Rising pattern above 99th percentile 🚨 |
| hs-Troponin T (Cobas) | <14 (all) | <14 | ng/L | >52 with rise 🚨 |
| NT-proBNP | <75y: <125; >75y: <450 | same | pg/mL | >900 HF likely; >35,000 🚨 |
| BNP | <100 | <100 | pg/mL | >500 HF likely; >1000 🚨 |
| CK (total) | 40–320 | 25–200 | U/L | >5000 🚨 |
| CK-MB | <25 U/L or <6% of total CK | same | U/L | >25 + rising = myocardial injury |
| Myoglobin | M:28–72; F:25–58 | µg/L | >1000 🚨 (rhabdomyolysis) | |
| LDH | 135–225 | 135–214 | U/L | — |
| D-Dimer | <0.5; age-adjusted threshold: age×0.01 µg/mL if >50y | µg/mL FEU | — | |
| Fibrinogen | 2.0–4.0 | g/L | <1.0 🚨 (DIC) | |
| Homocysteine | <15 | µmol/L | >30 🚨 (very high CV risk; B12/folate deficiency) | |
| Lp(a) | <125 nmol/L (<50 mg/dL) | nmol/L | >125 = high independent CV risk | |
| ApoB | M:<1.0; F:<0.9 optimal | g/L | >1.4 = elevated atherogenic risk | |
| ApoA1 | M:1.0–1.6; F:1.0–1.9 | g/L | <0.9 = low HDL capacity |
Serial Troponin Interpretation (ESC 0h/1h Algorithm):
NT-proBNP/BNP Framework:
| NT-proBNP (pg/mL) | BNP (pg/mL) | Interpretation |
|---|---|---|
| <125 (<75y) / <450 (>75y) | <100 | HF unlikely (high NPV) |
| 125–900 | 100–500 | Grey zone → echo + clinical |
| >900 | >500 | HF probable |
| >5000 | >1000 | Severe/decompensated HF |
| >35,000 | — | Critical — notify immediately 🚨 |
BNP Confounders: ↑ by: CKD, PE, sepsis, AF, thyrotoxicosis, large pericardial effusion | ↓ by: Obesity (BMI>35 reduces BNP up to 40% — NT-proBNP less affected)
CK-MB Index: CK-MB% = (CK-MB ÷ total CK) × 100; >6% = myocardial-specific; <6% = skeletal muscle origin (even if CK-MB absolute value elevated)
| Analyte | Reference | Units | Critical | Notes |
|---|---|---|---|---|
| Calcium (total) | 2.08–2.65 | mmol/L | <1.5 🚨 / >3.5 🚨 | Correct for albumin: Ca_corr = Ca_meas + 0.02 × (40 − albumin g/L) |
| Ionised Calcium | 1.15–1.32 | mmol/L | <0.8 🚨 / >1.6 🚨 | Gold standard; unaffected by albumin |
| Phosphate | 0.87–1.45 | mmol/L | <0.3 🚨 | Fasting preferred; IV glucose causes false low |
| Magnesium | 0.66–1.07 | mmol/L | <0.4 🚨 / >2.1 🚨 | Hypomagnesaemia causes PTH resistance |
| PTH (intact 1–84) | 1.6–7.2 | pmol/L | >30 (secondary hyperPTH) | Interpret alongside Ca and Vitamin D |
| 25-OH Vitamin D | >75 sufficient; 50–75 insufficient; 25–50 mild deficiency; <25 deficiency; <12 severe 🚨 | nmol/L | CBAHI minimum >50 nmol/L | |
| 1,25-(OH)₂ Vitamin D | 43–149 | pmol/L | — | Low in CKD G3+; high in granulomatous disease |
| ALP (total) | M:44–147; F:35–104 | U/L | >1500 | GGT needed to confirm hepatic vs bone origin |
| Bone-specific ALP (BSALP) | M:<22.5; F(pre):<14; F(post):<22.6 | µg/L | — | More specific than total ALP for bone turnover |
| P1NP (N-propeptide type 1 procollagen) | M:20–76; F(pre):19–83; F(post):16–96 | µg/L | — | IOF-preferred bone formation marker |
| CTX (β-C-terminal telopeptide) | M:<0.704; F(pre):<0.573; F(post):<0.704 | µg/L | — | Bone resorption; fasting 08:00 sample essential |
| Osteocalcin | M:12–55; F(pre):11–43; F(post):15–46 | µg/L | — | Bone formation; also reflects Vitamin K status |
| DPD (urine deoxypyridinoline) | F:3.0–7.4; M:4.0–19.0 | nmol/mmol Cr | — | Fasting 2nd void specimen |
PTH + Calcium Decision Matrix:
| Ca²⁺ | PTH | Interpretation |
|---|---|---|
| ↑ | ↑ or N-high | Primary hyperparathyroidism — parathyroid adenoma (80%)/hyperplasia/carcinoma |
| ↑ | ↓ | Malignancy (PTHrP), Vitamin D toxicity, sarcoidosis, granulomatous disease |
| N | ↑↑ | Secondary hyperparathyroidism — Vitamin D deficiency, CKD, malabsorption |
| ↓ | ↑↑ secondary → autonomous | Tertiary hyperparathyroidism (CKD long-standing) |
| ↓ | ↓ or low-N | Hypoparathyroidism (post-surgical, autoimmune) |
| ↓ | ↑ but PTH effect impaired | Hypomagnesaemia → PTH resistance — check Mg first |
Vitamin D Staging Actions:
75 nmol/L: sufficient — maintain dietary intake
250 nmol/L: toxicity — discontinue all supplements; hypercalcaemia risk
CKD + Bone Disease: CKD G3+: ↓1-α hydroxylation → ↓1,25-OH-D (active form) despite possibly adequate 25-OH-D stores. Supplement 25-OH-D to >75 nmol/L; use alfacalcidol or calcitriol for active form. Monitor Ca²⁺ and PTH 3-monthly.
Bone Turnover Monitoring (Osteoporosis):
| Analyte | Reference | Units | Critical | Notes |
|---|---|---|---|---|
| Vitamin B12 (cobalamin) | 145–569 | pmol/L | <110 probable deficiency 🚨 | Serum B12 may be normal (up to 300 pmol/L) with intracellular deficiency; use MMA/HoloTC to confirm |
| Vitamin B12 (pg/mL) | 197–771 | pg/mL | <150 probable deficiency | pmol/L × 1.355 = pg/mL |
| Serum Folate | >10 | nmol/L | <7 deficiency | Sensitive to last meal — use RBC folate for body stores |
| RBC Folate (erythrocyte) | >340 | nmol/L | <340 deficiency; <230 severe | Reflects 3-month body stores — most clinically reliable |
| Homocysteine (total) | <15 | µmol/L | >30 = very high CV risk + functional deficiency 🚨 | Elevated in B12 def, folate def, CKD, hypothyroidism |
| Methylmalonic acid (MMA) | <0.28 | µmol/L | >0.28 = functional intracellular B12 deficiency | Most specific marker of B12 deficiency |
| Holotranscobalamin (HoloTC) | >35 | pmol/L | <35 = early functional B12 deficiency (active fraction) | Better early marker than total B12 |
| Intrinsic Factor Ab (IF-Ab) | Negative | — | Positive = Pernicious Anaemia (specific ~95%; sensitive ~60%) | |
| Parietal Cell Ab (PCA) | Negative | — | Positive in ~80% PA; also in autoimmune gastritis | Less specific than IF-Ab |
| Gastrin (fasting) | <100 | pg/mL | >300 = PA or Zollinger-Ellison syndrome | Elevated in achlorhydria |
B12 Deficiency Interpretation Framework:
| Serum B12 | Homocysteine | MMA | HoloTC | Interpretation |
|---|---|---|---|---|
| <110 pmol/L | ↑ | ↑ | <35 | Definite B12 deficiency — treat immediately |
| 110–300 pmol/L | ↑ | ↑ | <35 | Functional B12 deficiency — treat despite borderline serum |
| 110–300 pmol/L | Normal | Normal | >35 | B12 probably adequate — repeat in 3 months |
| >300 pmol/L | Normal | Normal | >35 | B12 sufficient |
| Very high >2000 pmol/L | — | — | — | Investigate: liver disease, MPN, solid tumour |
Causes of B12 Deficiency:
Causes of Folate Deficiency:
B12 vs Folate Deficiency — Distinguishing:
| Feature | B12 Deficiency | Folate Deficiency |
|---|---|---|
| Megaloblastic anaemia | Yes | Yes |
| Subacute combined degeneration (neurological) | Yes — unique to B12 | No |
| Serum B12 | ↓ | Normal or ↑ |
| Serum folate | Normal or ↑ | ↓ |
| RBC folate | ↓ (secondary) | ↓ (primary) |
| Homocysteine | ↑ | ↑ |
| MMA | ↑ | Normal |
⚠️ CRITICAL RULE: NEVER treat megaloblastic anaemia with folate alone until B12 deficiency is excluded. Folate corrects haematological picture but neurological damage (subacute combined degeneration) continues and may become irreversible. Always check B12 first.
Treatment Protocols:
| Analyte | Reference | Units | Critical |
|---|---|---|---|
| CRP | <5 | mg/L | >100 (severe inflammation/sepsis) 🚨 |
| hs-CRP | <1.0 low CV risk; 1.0–3.0 intermediate; >3.0 high CV risk | mg/L | — |
| ESR (male) | <15 (<50y); <20 (>50y) | mm/hr | >100 (myeloma, giant cell arteritis, sepsis) |
| ESR (female) | <20 (<50y); <30 (>50y) | mm/hr | >100 |
| Procalcitonin (PCT) | <0.1 normal; 0.1–0.25 monitor; >0.25 bacterial likely; >2 sepsis; >10 septic shock | µg/L | >10 🚨 |
| IL-6 | <7 | pg/mL | >100 (cytokine storm) 🚨 |
| Lactate | 0.5–2.2 | mmol/L | >4 (septic shock) 🚨 |
| Ferritin (inflammatory) | M:30–300; F:15–200 | µg/L | >10,000 (HLH, Still's, MAS) 🚨 |
| Marker | Reference | Primary Organ | Key Notes |
|---|---|---|---|
| PSA (total) | <4.0 (<50y: <2.5) | Prostate | Also elevated in BPH, prostatitis; PSA density + velocity essential |
| AFP | <7 µg/L | Liver (HCC), testis (NSGCT) | Normal elevation in pregnancy |
| CEA | <3.0 (non-smoker); <5.0 (smoker) | Colorectal, lung, breast | Monitoring, not diagnosis |
| CA-125 | <35 U/mL | Ovary | Elevated in endometriosis, PID, fibroids, ascites |
| CA 19-9 | <37 U/mL | Pancreas, biliary | False positive in cholestasis; absent in Lewis antigen-negative |
| CA 15-3 | <25 U/mL | Breast | Recurrence monitoring |
| Beta-hCG | <5 IU/L | Trophoblastic, testis | Serial doubling in normal pregnancy |
| Calcitonin | M:<11.5; F:<4.6 pg/mL | Medullary thyroid cancer | |
| Chromogranin A | <100 µg/L | NETs, phaeochromocytoma | Falsely elevated with PPI use |
| 5-HIAA (24h urine) | 10–47 µmol/24h | Carcinoid | Avoid tryptophan-rich foods before collection |
All require direct clinician notification within 60 minutes (ISO 15189:2022 · JCAHO NPSG.02.03.01).
| Analyte | Critical Low | Critical High |
|---|---|---|
| Sodium | <120 mmol/L | >158 mmol/L |
| Potassium | <2.8 mmol/L | >6.2 mmol/L |
| Calcium (total) | <1.5 mmol/L | >3.5 mmol/L |
| Ionised Ca | <0.8 mmol/L | >1.6 mmol/L |
| Glucose | <2.2 mmol/L | >27.8 mmol/L |
| Magnesium | <0.4 mmol/L | >2.1 mmol/L |
| Phosphate | <0.3 mmol/L | — |
| Bicarbonate | <10 mmol/L | >40 mmol/L |
| Creatinine | — | >884 µmol/L (new) |
| Bilirubin (total) | — | >342 µmol/L |
| Ammonia | — | >55 µmol/L |
| Lactate | — | >10 mmol/L (>4 = septic shock) |
| TSH | <0.03 mIU/L | >100 mIU/L |
| FT4 | <6 pmol/L | >77 pmol/L |
| FT3 | — | >20 pmol/L |
| Cortisol (morning) | <83 nmol/L | — |
| hs-Troponin | — | Rising pattern above 99th percentile 🚨 |
| NT-proBNP | — | >35,000 pg/mL |
| BNP | — | >1000 pg/mL |
| CK | — | >5000 U/L |
| Myoglobin | — | >1000 µg/L |
| Triglycerides | — | >11.3 mmol/L |
| PT/INR | — | >6.0 |
| Fibrinogen | <1.0 g/L | — |
| Vitamin D | <12 nmol/L (severe) | >375 nmol/L (toxicity) |
| Vitamin B12 | <110 pmol/L + neurological sx | >2000 pmol/L (investigate cause) |
| PTH | — | >30 pmol/L (severe secondary) |
| Prolactin | — | >5000 mIU/L (macroadenoma likely) |
| Homocysteine |
Critical Value Protocol:
Apply CKD stage → electrolyte consequences → AKI vs CKD → pre/renal/post differentiation → CKD-MBD screen (PTH, Vit D, phosphate, BSALP)
R-ratio → injury pattern → de Ritis ratio → synthetic markers (albumin, INR, bilirubin) → Child-Pugh surrogate → aetiology (viral serology, autoimmune, iron studies, Caeruloplasmin, A1AT)
Full TSH algorithm table → pregnancy trimester-specific ranges if pregnant → drug effects → NTI exclusion → autoimmune assessment (anti-TPO, TRAb)
Cortisol timing critical — state sample time; morning cortisol < 83 = 🚨; ACTH correlation matrix → Cushing's screening algorithm → ARR for hyperaldosteronism; DHEA-S for adrenal androgen excess
Must know cycle day (female) or time of draw (male testosterone). Apply phase-specific ranges. LH:FSH ratio; AMH and inhibin B for ovarian reserve; prolactin: PEG precipitation before MRI if elevated; FAI for hyperandrogenism quantification; progesterone ovulation rule.
Serial troponin mandatory: apply ESC 0h/1h algorithm. Distinguish acute AMI (rising delta) from chronic myocardial injury (stable elevation). BNP/NT-proBNP: obesity confounds BNP (not NT-proBNP); CKD elevates both. CK-MB index >6% = myocardial. Homocysteine as CV risk marker — check B12/folate. Lp(a) for residual risk assessment.
Always albumin-correct calcium. PTH + Ca matrix → diagnosis. Vitamin D staging → supplement protocol. CKD: use active Vit D form. Bone turnover markers P1NP + CTX: fasting 08:00; monitor osteoporosis treatment (P1NP should fall >25% at 3–6 months). Identify high vs low turnover pattern.
Always measure both together. MMA = most specific for B12 deficiency. HoloTC = earliest functional marker. RBC folate = best for body stores (not serum folate). NEVER treat with folate alone until B12 excluded (neurological damage risk). Metformin users: check B12 annually.
| Pattern | Syndrome |
|---|---|
| ↑Creatinine + ↑K⁺ + ↑Phosphate + ↓Ca²⁺ + ↓HCO₃⁻ + ↑PTH | CKD with secondary hyperparathyroidism |
| ↑Bilirubin (indirect) + ↑LDH + ↓B12 or ↓folate + macrocytosis | Megaloblastic haemolytic anaemia |
| ↑Homocysteine + ↓B12 + ↑MMA | B12 deficiency — treat urgently |
| ↑Homocysteine + ↓RBC folate + normal MMA | Folate deficiency (B12 excluded) |
| ↓Ca²⁺ + ↑PTH + ↓25-OH-Vit D | Vitamin D deficiency with secondary hyperPTH |
| ↑Ca²⁺ + ↓PTH + ↑ALP + clinical malignancy | Malignancy-associated hypercalcaemia |
| ↑Ca²⁺ + ↑PTH + ↓Phosphate | Primary hyperparathyroidism |
| ↑Troponin (rising delta) + ↑NT-proBNP | AMI with cardiac decompensation |
| ↑NT-proBNP stable + ↑creatinine | Cardiorenal syndrome |
| ↑TSH + ↓FT4 + ↑cholesterol + ↑CK + ↑homocysteine | Hypothyroidism |
| ↓TSH + ↑FT4 + ↑ALP + ↑Ca²⁺ + ↑P1NP/CTX | Hyperthyroidism with high bone turnover |
| LH:FSH >2:1 + ↑testosterone + FAI>5 + ↓SHBG + ↑insulin + ↑TG | PCOS with metabolic syndrome |
| LH ↑↑ + FSH ↑↑ + E2 ↓↓ (<40y) | Premature ovarian insufficiency |
| ↓Cortisol + ↑K⁺ + ↓Na⁺ + ↓glucose + ↑ACTH | Addison's disease |
| ↑Cortisol + ↑glucose + ↑Na⁺ + ↓K⁺ + ↓ACTH | Adrenal Cushing's syndrome |
| ↑Prolactin + ↓LH + ↓FSH + ↓E2/T | Hyperprolactinaemia → hypogonadism |
| ↑P1NP + ↑CTX + ↑ALP + ↑Ca²⁺ | High bone turnover — Paget's, mets, hyperPTH |
| ↑Glucose + ↑HbA1c + ↑TG + ↓HDL | Metabolic syndrome / T2DM |
| ↑ALT + ↑AST + ↑TG + ↑glucose + ↑ferritin + ↓ALP:GGT ratio <1 | NAFLD/NASH |
| ↑CRP + ↑PCT + ↑Lactate + ↓Albumin | Sepsis — apply SOFA |
| Very high ferritin (>10,000) + ↑LDH + ↑TG | Haemophagocytic lymphohistiocytosis (HLH) 🚨 |
Patient: Age ___ | Sex ___ | Sample ID: ___ Instrument: [Atellica CH/IM / Cobas / specify] | Date: ___ Fasting: [Yes/No/Unknown] | Sample time: ___ | Cycle day (F): ___ Clinical context: ___ | QC: ___
| Analyte | Result | Threshold | Required Action |
|---|---|---|---|
| [Name] | X | >X / <X | 🚨 CALL CLINICIAN WITHIN 60 MIN — document time, name, value |
State "No critical values identified" if none.
| Analyte | Result | Unit | Reference (Age/Sex) | Status | Note |
|---|---|---|---|---|---|
| [Name] | X | unit | range | ✅/⬆️/⬇️/⚠️/🚨 | Brief clinical note |
✅ Normal · ⬆️ Elevated · ⬇️ Low · ⚠️ Borderline · 🚨 Critical
3A. Renal Function: eGFR stage · electrolyte pattern · AKI vs CKD · CKD-MBD implications 3B. Liver Function: R-ratio · injury pattern · de Ritis ratio · synthetic markers · likely aetiology 3C. Metabolic/Glucose: Glycaemic status · HbA1c classification · lipid CV risk · HOMA-IR if insulin available 3D. Iron Studies: Pattern (IDA/ACD/overload/haemolysis) · CBC integration 3E. Thyroid (TSH/FT4/FT3/antibodies): Full algorithm → diagnosis · severity · drug effects considered 3F. Adrenal (Cortisol/ACTH/Aldosterone/DST): Timing noted · axis interpretation · Cushing's/Addison's assessment 3G. Reproductive & Fertility: Cycle phase noted · LH/FSH/E2/P4/T/PRL/AMH/Inhibin B → diagnosis · FAI 3H. Cardiac Function: Serial troponin delta · BNP/NT-proBNP framework · CK-MB index · D-Dimer 3I. Bone Health (PTH/Vit D/Ca/P1NP/CTX): PTH-Ca matrix → diagnosis · Vit D staging · turnover markers 3J. Vitamin B12 & Folate: B12 framework (serum + MMA + HoloTC) · folate (RBC folate preferred) · homocysteine · B12 vs folate distinction · cause · treatment protocol 3K. Inflammatory Markers: CRP/PCT/ESR/IL-6 → severity · bacterial vs viral · sepsis risk 3L. Tumour Markers: Clinical context mandatory — never diagnose malignancy on marker alone
Primary Finding: [Most clinically significant result] Secondary Findings: [Additional abnormalities and their inter-relationships] Overall Pattern: [Syndrome-level: e.g., "CKD G3b with secondary hyperparathyroidism, Vitamin D deficiency, concurrent B12 deficiency from metformin use, and borderline hypothyroidism"] Confidence: High / Moderate / Requires confirmatory testing
Excluded: [Condition] — excluded because [specific results]
| Item | Status | Note |
|---|---|---|
| Serum indices H/I/L | Reported / Normal / Flagged | Action if flagged |
| QC status | Passed / Unknown | |
| Sample timing (hormones) | Appropriate / Unknown | Cortisol: must be 08:00–09:00; testosterone: morning |
| Cycle day (female hormones) | Known / Unknown | Reference ranges cannot be applied without cycle day |
| Biotin interference | Not suspected / Suspected | 24h washout + repeat if suspected |
| Heterophile Ab / Macro-PRL | Not applicable / Check | PEG test if prolactin elevated + asymptomatic |
| Method notes | Jaffé creatinine, TBG effects on Total T4/T3, HbA1c method limitations |
🚨 IMMEDIATE (critical values — within 60 minutes):
SHORT-TERM (within 24–48 hours):
FURTHER INVESTIGATIONS:
CLINICIAN COMMUNICATION:
INSTRUMENT/QC ACTIONS:
[3–5 sentence summary: (1) most significant findings, (2) integrated syndrome pattern, (3) key diagnoses to confirm or exclude, (4) single most critical next action.]
| Issue | Trigger | Action |
|---|---|---|
| H/I/L serum index flagged | Auto-reported | Per SOP: note/reject; fresh sample |
| Jaffé creatinine elevated | Ketoacidosis, cephalosporins | Switch to enzymatic creatinine |
| ALP elevated + GGT normal | Bone pattern | Request BSALP or P1NP |
| HbA1c interference | Haemoglobinopathy present | Use boronate affinity; correlate with plasma glucose |
| IMT (electrolyte) calibration failure | Na/K/Cl flagged * | Run ISE calibrator; service call if persists |
| Westgard rule violation | Levey-Jennings plot | 1-3s: reject; hold patients; investigate |
| Biotin suspected | TSH suppressed + asymptomatic | 24h washout; repeat all affected assays |
| CTX result high | Sample not fasting or not 08:00 | Restate collection instructions; repeat |
| Issue | Trigger | Action |
|---|---|---|
| Prozone effect | Very high conc → falsely low | Auto-dilution check; manual serial dilution |
| Heterophile Ab | Discordant troponin/TSH/PSA | Blocking tubes; alternate immunoassay method |
| Macro-prolactin | High PRL + asymptomatic | PEG precipitation; <40% recovery = macro-PRL |
| Delta check failure | >50% change in stable analyte | Verify patient ID; repeat before reporting |
| Vitamin D variation | Seasonal; different lots | Use DEQAS-standardised method; note season |
| B12/folate haemolysis | H flag on sample | Reject; haemolysis falsely lowers folate (releases RBC folate into serum) |
| ACTH sample instability | Degradation if delayed >15 min on ice | Centrifuge immediately; freeze at −20°C; never leave at room temperature |
"Interpret my chemistry / hormone panel / thyroid / cortisol / ACTH / LH / FSH / fertility hormones / testosterone / prolactin / AMH / cardiac markers / troponin / BNP / bone health / PTH / Vitamin D / P1NP / CTX / vitamin B12 / folate / homocysteine / inflammatory markers / lipids / tumour markers / critical values"
| Phrase | Output |
|---|---|
| (default) | Full 8-section report |
| "quick summary" | Sections 1 + 8 only |
| "just critical values" | Section 1 only |
| "thyroid only" | Section 3E + relevant 2E rows + action |
| "adrenal only" | Section 3F + 2F rows + action |
| "fertility / reproductive" | Section 3G + 2G rows + action |
| "cardiac only" | Section 3H + 2H rows + action |
| "bone health" | Section 3I + 2I rows + action |
| "B12 folate" | Section 3J + 2J rows + treatment protocol |
| "liver only" | Section 3B + 2B rows + action |
| "kidney only" | Section 3A + 2A rows + action |
| "iron studies" | Section 3D + 2D pattern + action |
| "inflammatory markers" | Section 3K + 2K rows + action |
EEHLSS / MedLabAI-LIS | Maintained by Echukwuka | Version 2.0 — April 2026 Aligned to: IFCC · CLSI · ISO 15189:2022 · JCAHO NPSG.02.03.01 · CBAHI · SFDA · ESC 2023 · Endocrine Society · IOF · NICE · KDIGO 2022 All results require validation by a qualified Medical Laboratory Scientist or Clinical Biochemist. This skill provides clinical decision support only — not a substitute for clinical judgement or face-to-face patient assessment.
| — |
| >100 µmol/L (metabolic disorder) |
| Ferritin | — | >10,000 µg/L (HLH/Still's) |
| Aldosterone:Renin Ratio | — | >750 (Conn's screen positive) |