MAGENT

NEXUS criteria: the five C-spine findings and how they combine

The NEXUS criteria are five yes/no findings used after blunt trauma to the neck: posterior midline cervical-spine tenderness, a focal neurologic deficit, altered alertness, intoxication, and a painful distracting injury. A person meets the NEXUS low-risk criteria when all five are absent, meaning no midline tenderness, no deficit, normal alertness, no intoxication and no distracting injury. If any one of the five is present, the low-risk criteria aren't met.

Not a medical device. Not a diagnosis or dosing recommendation.

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What are the NEXUS criteria?

NEXUS stands for the National Emergency X-Radiography Utilization Study. The criteria come from a study led by Jerome R. Hoffman and William R. Mower, published in the New England Journal of Medicine in 2000. They're also called the NEXUS C-spine rule, the NEXUS low-risk criteria, the NEXUS five criteria or Hoffman NEXUS.

The study abstract calls them a decision instrument that "required patients to meet five criteria in order to be classified as having a low probability of injury."

This page explains the five findings and how they combine. It doesn't say what to do when the criteria are or aren't met, and it doesn't diagnose a neck injury.

The NEXUS logic

low-risk criteria met = NOT midline_cervical_tenderness
                    AND NOT focal_neuro_deficit
                    AND normal_alertness
                    AND NOT intoxication
                    AND NOT distracting_injury

Exact expression the calculator uses:

NEXUS low-risk iff no posterior midline cervical-spine tenderness and no focal neurologic deficit and normal alertness and no intoxication and no painful distracting injury

In words: every one of the five low-risk conditions has to hold. There are no points and no partial credit. One failed condition is enough for the low-risk criteria not to be met.

What each input means

InputPlain-English meaningLow-risk condition holds when
midline_cervical_tendernessTenderness when pressing the back of the neck along the midline of the cervical spinefalse (no tenderness)
focal_neuro_deficitA focal neurologic deficit, such as weakness or numbness in one areafalse (no deficit)
normal_alertnessThe person is fully alerttrue (alertness is normal)
intoxicationThe person is intoxicatedfalse (not intoxicated)
distracting_injuryA painful injury elsewhere that could distract from neck painfalse (no distracting injury)

Notice that one input runs the other way. For four inputs, "true" means a problem is present and the condition fails. For normal_alertness, "true" means alertness is normal and the condition holds.

How the logic works

  1. Midline tenderness. If the back of the neck is tender in the midline, stop: the low-risk criteria aren't met.
  2. Focal deficit. If there is a focal neurologic deficit, the criteria aren't met.
  3. Alertness. If alertness is altered, the criteria aren't met.
  4. Intoxication. If the person is intoxicated, the criteria aren't met.
  5. Distracting injury. If there is a painful distracting injury, the criteria aren't met.
  6. If none of steps 1–5 stopped you, the low-risk criteria are met.

The order doesn't change the answer. It's written as steps because that's how people usually go through it.

What the calculator returns

Magent's calculator takes the five true/false answers from the person examining the patient. It returns whether the low-risk criteria are met, the opposite of that as a second true/false field, and a line for each of the five findings showing whether that condition held. It doesn't take age, and it doesn't examine anyone.

Worked examples

These use Magent's own expected values for the calculator.

Example 1: all five conditions hold

  1. No midline tenderness, no focal deficit, normal alertness, no intoxication, no distracting injury.
  2. Low-risk criteria: met.

Example 2: midline tenderness alone

  1. Midline cervical tenderness: present. Everything else holds.
  2. Low-risk criteria: not met.

Example 3: focal deficit alone

  1. Focal neurologic deficit: present. Everything else holds.
  2. Low-risk criteria: not met.

Example 4: altered alertness alone

  1. normal_alertness is false. Everything else holds.
  2. Low-risk criteria: not met.

Example 5: intoxication alone

  1. Intoxication: present.
  2. Low-risk criteria: not met.

Example 6: distracting injury alone

  1. A painful distracting injury: present.
  2. Low-risk criteria: not met.

NEXUS combination table

Each row is one of Magent's expected values for the calculator.

Midline tenderFocal deficitNormal alertnessIntoxicatedDistracting injuryLow-risk criteria met?
NoNoYesNoNoYes
YesNoYesNoNoNo
NoYesYesNoNoNo
NoNoNoNoNoNo
NoNoYesYesNoNo
NoNoYesNoYesNo

History of the NEXUS criteria

The criteria come from Jerome R. Hoffman, William R. Mower, Allan B. Wolfson, Knox H. Todd, Michael I. Zucker and the National Emergency X-Radiography Utilization Study Group, Validity of a set of clinical criteria to rule out injury to the cervical spine in patients with blunt trauma, New England Journal of Medicine, 2000 (volume 343, issue 2, pages 94–99).

The abstract describes the background this way: "Because clinicians fear missing occult cervical-spine injuries, they obtain cervical radiographs for nearly all patients who present with blunt trauma." Earlier work had suggested that a set of clinical criteria could pick out patients with an extremely low probability of injury.

The study was "a prospective, observational study of such a decision instrument at 21 centers across the United States." It looked at 34,069 patients who had radiography of the cervical spine after blunt trauma.

When it's used

The NEXUS criteria apply to patients after blunt trauma, as in the 2000 study. Magent's record describes the calculator as the published rule for blunt-trauma adults, with the caller assigning each of the five findings.

Where it's used

The original study ran in 21 centers across the United States.

Who uses it

The study abstract describes the criteria as a "simple decision instrument based on clinical criteria" for physicians assessing patients after blunt trauma.

Limits of the calculation

  • It combines five yes/no findings. It doesn't examine the neck and doesn't diagnose an injury.
  • It's the NEXUS C-spine criteria. It isn't the Canadian C-spine rule, NEXUS chest or NEXUS head CT.
  • It doesn't take age. The record describes the population as blunt-trauma adults as published.
  • Each finding is assigned by the person using it. The calculator doesn't decide whether an injury is "distracting" or whether someone is intoxicated.
  • This page doesn't say what to do when the criteria are or aren't met.

Clinical decisions belong to a qualified clinician who knows the patient.

  • Canadian C-spine rule is a different rule for the same question. It uses age, a dangerous mechanism, paresthesias, five low-risk factors and the ability to rotate the neck, applied in a set order.
  • Ottawa ankle rule uses the same yes/no style for a different body part: malleolar pain, malleolus tenderness and weight bearing.

Glossary

  • Cervical spine (C-spine): the seven bones of the neck.
  • Posterior midline: the center line at the back of the neck, over the spine.
  • Focal neurologic deficit: a loss of function, such as weakness or numbness, in one specific area.
  • Distracting injury: another painful injury that might stop someone noticing or reporting neck pain.
  • Blunt trauma: injury from impact rather than a penetrating wound.

Common mistakes

  • Reading normal_alertness backwards. "True" means alertness is normal, which is the low-risk answer.
  • Adding up findings. NEXUS isn't a score. Any single failed condition means the low-risk criteria aren't met.
  • Mixing it up with NEXUS chest or NEXUS head CT. Those are separate instruments with their own criteria.
  • Mixing it up with the Canadian C-spine rule. The two rules use different findings and combine them differently.

Source

Hoffman JR, Mower WR, Wolfson AB, Todd KH, Zucker MI; National Emergency X-Radiography Utilization Study Group. Validity of a set of clinical criteria to rule out injury to the cervical spine in patients with blunt trauma. N Engl J Med. 2000;343(2):94-99. DOI: 10.1056/NEJM200007133430203

Frequently asked questions

What are the NEXUS criteria?

Five findings after blunt trauma: no posterior midline cervical tenderness, no focal neurologic deficit, normal alertness, no intoxication and no painful distracting injury. All five must hold for the low-risk criteria to be met.

What does NEXUS stand for?

National Emergency X-Radiography Utilization Study.

When do the NEXUS criteria say a C-spine x-ray is needed?

This page doesn't give disposition advice. It shows how the five findings combine; what to do next depends on the clinical context.

Is NEXUS a score?

No. There are no points. The low-risk criteria are either met (all five hold) or not met (any one fails).

Do the NEXUS criteria use age?

Magent's calculator doesn't take age. The caller assigns the five findings.

Is NEXUS the same as the Canadian C-spine rule?

No. They're separate rules built from different studies and findings.

Who developed the NEXUS criteria?

Jerome Hoffman, William Mower and the NEXUS group, in a 2000 paper in the New England Journal of Medicine.