Lab Fishbone Diagram Maker for BMP, CBC and Other Labs
Generate lab fishbone diagrams from your results: BMP (Chem-7), CBC, coagulation, LFT, ABG and Ca/Mg/Phos skeletons with each value in its standard slot. Made for case presentations, nursing notes and clinical teaching.
Lab fishbone styles
Each style is shown on a set of its own: a liver work-up with the LFT cross beside its coags, a full electrolyte set with Ca / Mg / Phos in blue ballpoint on a ruled sheet, an empty BMP, CBC, coag and Ca / Mg / Phos template with the analyte name in every place, and a DKA case's BMP and blood gas. Choosing a card loads the prompt that drew it.
Lab fishbone diagram examples
Renders of the four starters: an admission BMP and CBC with two values marked H, a pasted CMP split into the BMP, the calcium fork and the LFT cross, a BMP trended over two days, and coags beside a CBC with two values marked low. Click one to load its prompt.
What is a lab fishbone diagram?
A lab fishbone diagram is the shorthand clinicians, nurses and medical students use to write lab results: a few lines form a skeleton for each panel, and every analyte has a fixed place in it, so a number is read as the sodium or the platelet count by where it sits, with no names and no units. The one most people mean is the BMP (Chem-7) fishbone, a horizontal line split into three compartments with sodium, chloride and BUN above, potassium, bicarbonate and creatinine below, and glucose in the fork at the end that gives the figure its fish tail. The CBC, coagulation, liver and Ca / Mg / Phos panels each have a smaller skeleton of their own, and the blood gas is written along slashes. The notation grew up in handwritten progress notes and on nurses' report sheets, which is why it is also called a lab skeleton diagram, and some electronic health records still draw it.
What this lab fishbone maker does with your results
- Each value goes to its slot in code. Sodium is always the upper left of the BMP, glucose always the tail, hemoglobin always above the CBC line: the model is told the place of every number and never chooses one.
- Values are copied, never judged. Nothing is compared with a reference range and nothing is flagged on its own. An H, L, ↑, (low) or critical you write next to a value is drawn exactly as you wrote it, and a value you mark circled gets a circle.
- Printouts work. Paste a lab report with its units and reference ranges and only the results are placed: the units are left off, as the notation does, unless you ask for them, and the range numbers are never read as results.
- The two HCO3 values are kept apart. Bicarbonate from the chemistry goes in the BMP, the one from a blood gas in the ABG line, even when both are typed in one sentence.
- Up to six skeletons in one figure, for example a BMP and a CBC on each of two days with the date above each. Results that fit no skeleton, such as lactate, troponin or a differential, are written once below them with their names.
Lab fishbone diagrams by panel, and where each value goes
Most requests are one of these eight. Each panel has its own skeleton, and its places do not move from one patient to the next.
BMP fishbone (Chem-7 fishbone)
The basic metabolic panel's seven values on one line in three compartments: Na, Cl and BUN on top, K, HCO3 and creatinine below, glucose in the fish tail at the right. Each column pairs two values read together (sodium over potassium, chloride over bicarbonate, BUN over creatinine). A lab that reports CO2 or total CO2 instead of HCO3 fills the same lower middle cell.
CBC fishbone diagram
The complete blood count without its differential: WBC in the left fork, hemoglobin above the line, hematocrit below it, platelets in the right fork. The four-slot bone has no place for the indices or the differential, so MCV, RDW or a neutrophil count you include are written beside it with their names.
CMP fishbone
A comprehensive metabolic panel does not fit one skeleton. It is drawn as three: the BMP fishbone, its calcium at the top of the Ca / Mg / Phos fork, and the liver values in the LFT cross with total protein and albumin beside it. Paste the whole CMP and it is split that way, with the magnesium and phosphorus places left empty when they were not sent.
Electrolyte fishbone
On most wards the electrolytes are the BMP fishbone plus the fork hung under it: calcium between the arms, magnesium left of the stem, phosphorus right of it. It is the set electrolyte replacement protocols usually cover, which is why many report sheets print an empty pair for every patient.
LFT fishbone (liver function tests)
Two crossed lines: total bilirubin in the top wedge with direct bilirubin under it, AST on the left, ALT on the right, alkaline phosphatase below. Total protein and albumin are written beside the cross with their names. Of all the skeletons this one varies most between hospitals and textbooks, so compare it with the version your unit uses.
ABG fishbone
The arterial blood gas is usually written along long slashes rather than drawn as a skeleton: pH / PaCO2 / PaO2 / HCO3, then SaO2 and base excess when reported. Type it the same way (7.12/22/96/8) or with names. A venous gas goes on the same line, with an empty place where it has no oxygen value.
Coag fishbone
An upside-down Y: PT to the left of the stem, PTT to the right, INR below between the two legs. An aPTT takes the PTT place. Coags are usually drawn beside a CBC, since the platelet count and the clotting times are read together before a procedure or a heparin change.
Lab fishbone template
Name the panels and ask for a template and the skeletons come out with no numbers, the analyte name in gray in each place, ready to print for a report sheet, a skills lab or flashcards. Ask for it unlabeled to get bare lines to fill in by hand at the bedside.
Where every value sits on each lab fishbone
The places this tool uses, the common convention in North American charting. Hospitals and courses vary, the liver cross most of all.
| Skeleton | Shape | Places |
|---|---|---|
| BMP (Chem-7) | A line in three compartments with a forked tail | Top: Na | Cl | BUN · bottom: K | HCO3 | Cr · tail: glucose |
| CBC | A line with a fork at each end | Left fork: WBC · above: Hgb · below: Hct · right fork: Plt |
| Ca / Mg / Phos | A Y, hung under the BMP | Between the arms: Ca · left of the stem: Mg · right: Phos |
| Coags | An upside-down Y | Left of the stem: PT · right: PTT · between the legs: INR |
| LFT | An X | Top: T bili (D bili) · left: AST · right: ALT · bottom: ALP |
| ABG | Values along slashes | pH / PaCO2 / PaO2 / HCO3, then SaO2 / BE |
Units are left off, as the notation does: the place already says which analyte it is, and the unit is your lab's. Ask for units when the reader may work in others, for example glucose in mg/dL for one class and mmol/L for another.
How to write labs in a fishbone diagram
Draw one skeleton per panel and per draw
A BMP fishbone, a CBC fishbone, and the smaller forks for Ca / Mg / Phos and coags. When you compare days, draw the set again for each draw and write the date or time above it.
Put each number in its fixed place
Copy the result without its unit: 138 in the upper left of a BMP is the sodium wherever the note is read. If a test is pending or was not sent, leave its place empty rather than moving the others along.
Mark what you want noticed
Many clinicians circle, arrow or write H and L beside the values that matter. That call is yours: this tool draws exactly the marks you add and never flags a value against a reference range.
Lab fishbone diagram vs Ishikawa fishbone diagram
A lab fishbone is a shorthand for writing one patient's lab results; an Ishikawa (cause-and-effect) fishbone is a chart for listing the possible causes of a problem. They share a name because both look a little like a fish skeleton, and nothing else.
| Lab fishbone | Ishikawa fishbone | |
|---|---|---|
| What it records | Lab results from one blood draw | Possible causes of one problem |
| Shape | Small fixed skeletons, one per panel | A spine to the problem, cause categories as ribs |
| Where each item goes | Fixed by convention (Na is always top left) | Chosen by the team |
| What is written in it | Numbers only | Words: causes and sub-causes |
| Who uses it | Nurses, residents and students on the wards | Quality and patient safety teams |
A search for a medical or nursing fishbone diagram can mean either. This page draws the lab one.
Lab fishbone questions, answered
What goes where on a BMP fishbone?
Sodium, chloride and BUN go along the top, potassium, bicarbonate (CO2) and creatinine along the bottom, and glucose sits in the fork at the right end. Read across, the top row is the main cation, the main anion and the urea; down each column the two values are read as a pair, BUN over creatinine for the kidneys. Some notes write calcium, magnesium and phosphorus to the right of the glucose; here they go in the Ca / Mg / Phos fork under the BMP.
How do you read a CBC fishbone?
The number in the left fork is the white count, the one above the line is hemoglobin, the one below is hematocrit and the one in the right fork is the platelet count. So 13.8 > 10.2 over 31.0 < 188 reads WBC 13.8, Hgb 10.2, Hct 31.0, platelets 188. The differential and the red cell indices are not part of the skeleton and are written beside it when needed.
Is the CO2 on a BMP fishbone the same as the PaCO2 of a blood gas?
No. The CO2 on a chemistry panel is total CO2, measured almost entirely as bicarbonate, and it goes in the HCO3 place of the BMP. PaCO2 is the partial pressure of carbon dioxide in arterial blood, a different number in mmHg, and it goes in the second place of the ABG line. When both are typed in one request, each is placed in its own skeleton.
Where do calcium, magnesium and phosphorus go on a lab fishbone?
In their own small fork, usually drawn under the BMP: calcium between the two arms, magnesium to the left of the stem and phosphorus to the right. This set is what people call the Chem-10 (the Chem-7 plus Ca, Mg and Phos), and the set most electrolyte replacement protocols cover.
Why does a lab fishbone have no units or labels?
Because the place is the label. Everyone who reads the chart knows the upper left of a BMP is sodium, so writing Na and mmol/L every time only adds clutter. Units are added when the reader may not share them, and analyte names are useful while learning the layout, which is what the teaching handout style does.
Does the tool flag abnormal lab values?
No, and on purpose. Reference ranges differ between laboratories, and which value to point out is a clinical decision. The tool never compares a value with a range and never colours or arrows one on its own; it draws the marks you write (H, L, ↑, ↓, critical, circled) exactly where you wrote them and nothing else.
Can I paste lab results from the EHR or a printout?
Yes: paste the results as text in any order, with or without units and reference ranges, and each value is matched to its analyte and placed. Leave out the patient's name, medical record number, date of birth and any other identifier before you paste; the figure needs only the numbers, and a date or a label such as Day 3 is enough to tell draws apart.
How do you show lab values trending over several days?
Draw the same skeleton once per draw, side by side, with the date or time above each. Type the results line by line with a heading, for example 11/03: Na 128, K 3.1 … and 11/04: Na 131, K 3.6 …, and up to six skeletons are laid out left to right in that order.
How do you write an ABG in fishbone form?
Along slashes, in a fixed order: pH / PaCO2 / PaO2 / HCO3, followed by SaO2 and base excess when they are reported. 7.12/22/96/8 reads pH 7.12, PaCO2 22, PaO2 96, HCO3 8. A missing value keeps an empty place, so the order still reads right.
Is a lab fishbone the same as the fishbone diagram used in nursing quality improvement?
No. The fishbone diagram of quality improvement is the Ishikawa cause-and-effect chart, used to sort the causes of a problem such as patient falls into categories. A lab fishbone is only a way of writing lab results. If your request describes causes rather than results, it is not a figure this page draws.
Sources
- Basic metabolic panel (the standard grid, glucose to its right) — Wikipedia
- Which lab value skeleton diagrams are used for discrete, CBC/CBC diff, chem, and coag results? — Medical Sciences Stack Exchange
- Medical Lab Diagrams (Chem 7 and CBC skeletons drawn in SVG) — Luke Murray, Observable
Keep exploring
Our other diagram tools, and the guides behind them.
Write your labs as fishbones
From a pasted panel to BMP, CBC and coag skeletons with every value in its place, in about a minute.
Make a lab fishbone