About the West Haven Criteria for Hepatic Encephalopathy
Grade II is the line that matters. The West Haven criteria sort hepatic encephalopathy into five levels — grade 0 with no detectable abnormality, grade I with trivial loss of awareness and a shortened attention span, grade II with lethargy, disorientation to time and obvious asterixis, grade III with somnolence and gross disorientation but a response to stimuli, and grade IV with coma. Grades 0 and I together with minimal hepatic encephalopathy make up covert disease, which needs psychometric testing to find; grade II and above is overt, which is what triggers treatment, a search for the precipitant and a change in where the patient is looked after.
Interpreting the result
Grade 0 means nothing was found on examination — it does not mean the brain is unaffected, and minimal hepatic encephalopathy is present in a substantial proportion of patients graded 0, detectable only on psychometric or neurophysiological testing and relevant because it impairs driving and quality of life. Grade I is subtle and inherently subjective: it depends on knowing the patient's baseline, and it is where inter-rater agreement is weakest. From grade II the findings become objective enough to be reliable, and grade II is the operational threshold — treat, look hard for a precipitant, and reconsider where the patient is being nursed. Grade III means somnolence with a preserved response to stimuli and should prompt an assessment of airway protection and a monitored setting. Grade IV is coma, requiring intensive care, and a patient who reaches it should be discussed for transplantation if not already.
| Score | Band | What it means | Action |
|---|---|---|---|
| Grade 0 | Unimpaired | No abnormality on clinical examination. Minimal hepatic encephalopathy may still be present and is not excluded by a normal examination | Consider psychometric or neurophysiological testing where driving, work safety or unexplained functional decline is the question |
| Grade I | Covert | Trivial lack of awareness, euphoria or anxiety, shortened attention span, impaired addition or subtraction, altered sleep rhythm | Needs knowledge of the patient's baseline to detect. Review precipitants and adherence; agreement between examiners is poorest at this grade |
| Grade II | Overt — the treatment threshold | Lethargy or apathy, disorientation to time, obvious personality change, inappropriate behaviour, dyspraxia, asterixis | Start treatment and search for a precipitant — infection, bleeding, constipation, diuretics, sedatives, renal impairment |
| Grade III | Overt — semi-stupor | Somnolence to semi-stupor but responsive to stimuli, confusion, gross disorientation, bizarre behaviour | Monitored setting; assess airway protection actively. Escalate care rather than waiting for grade IV |
| Grade IV | Coma | Coma, unresponsive to verbal or noxious stimuli | Secure the airway, manage in intensive care, and discuss transplant candidacy |
What the West Haven Criteria needs (1 inputs)
- Clinical findings on examination
- A single selection: the highest grade whose features are present. The criteria are read as a hierarchy, not a checklist, so a patient with obvious asterixis and disorientation to time is grade II even if some grade III features are absent.
What it returns
- West Haven grade (0 to IV)
- Recorded as 0, I, II, III or IV. Conventionally written in Roman numerals for grades I–IV, which is worth matching in the notes since '2' and 'II' occasionally get transcribed inconsistently between systems.
- Covert or overt classification
- Grade 0 and grade I are covert; grade II and above are overt. This binary is what most management decisions actually hinge on, and the guideline uses it explicitly.
How it is calculated
The grading is descriptive and consensus-based rather than fitted to outcome data. It originated at the West Haven Veterans Administration hospital as the assessment scheme used in a 1977 trial comparing lactulose with neomycin for chronic portosystemic encephalopathy, where a reproducible severity measure was needed as a trial endpoint — the grades were built to be scored at the bedside by the trial clinicians, which is why the anchors are ordinary examination findings rather than test results. A 2002 working party report at the World Congresses of Gastroenterology formalised the nomenclature and added minimal hepatic encephalopathy as a category below grade I, and the 2014 AASLD/EASL guideline consolidated the covert-versus-overt split that is now standard. Nothing in the system is weighted or summed; it is an ordinal scale of clinical description.
Facts & figures
| Category | West Haven grade | How it is detected |
|---|---|---|
| Minimal hepatic encephalopathy | Below grade I — examination normal | Psychometric or neurophysiological testing only |
| Covert hepatic encephalopathy | Minimal HE and grade I | Testing, or a subtle change apparent to someone who knows the patient |
| Overt hepatic encephalopathy | Grades II, III and IV | Bedside examination — disorientation and asterixis onward |
The covert/overt division is the one that changes management, and it falls between grade I and grade II. A patient described as having 'mild encephalopathy' could be on either side of it, which is why the grade rather than the adjective belongs in the notes.
| Category | Examples |
|---|---|
| Infection | Spontaneous bacterial peritonitis, urinary tract infection, pneumonia — diagnostic paracentesis is mandatory where ascites is present |
| Gastrointestinal bleeding | Variceal or non-variceal; the nitrogen load and the hypovolaemia both contribute |
| Drugs | Benzodiazepines, opioids, and any recent sedative — including those given for endoscopy |
| Renal and electrolyte | Acute kidney injury, hyponatraemia, hypokalaemia, over-diuresis |
| Constipation and dehydration | Common, easily corrected, and frequently the only precipitant found |
| Portosystemic shunt | TIPS, or a spontaneous shunt — consider imaging if episodes recur without another cause |
Encephalopathy in cirrhosis is usually precipitated rather than spontaneous, so a grade II presentation with no precipitant identified means the search is incomplete, not that none exists.
Evidence
Origin — West Haven VA lactulose versus neomycin trial
1977The grading scheme was introduced as the severity assessment used in a controlled comparison of lactulose and neomycin for chronic portal-systemic encephalopathy at the West Haven Veterans Administration hospital, where it served as the trial's clinical endpoint rather than as a separately derived instrument.
Consensus-descriptive; no sensitivity, specificity or C-statistic exists or could exist, because there is no independent reference standard for the severity of hepatic encephalopathy.
Nomenclature standardisation — Working Party, 2002
2002Final report of the Working Party at the 11th World Congresses of Gastroenterology, which defined the nomenclature, diagnosis and quantification of hepatic encephalopathy and established minimal hepatic encephalopathy as a category below grade I.
Formalised the classification by type (A, B, C), by duration and by severity, and made explicit that a normal examination does not exclude cognitive impairment.
Guideline adoption — AASLD/EASL, 2014
2014Joint practice guideline of the American Association for the Study of Liver Diseases and the European Association for the Study of the Liver on hepatic encephalopathy in chronic liver disease.
Adopted West Haven as the standard severity grading and consolidated the covert (minimal plus grade I) versus overt (grades II–IV) division used in practice and in trials.
Guideline update — EASL, 2022
2022EASL clinical practice guidelines on the management of hepatic encephalopathy, revisiting classification, diagnosis and treatment.
Retains West Haven grading while restating its known weakness — poor inter-observer reproducibility at the covert end — and emphasising that grade I requires knowledge of the patient's baseline.
How it compares
West Haven Criteria vs Glasgow Coma Scale
Not interchangeable — West Haven grades the specific syndrome of hepatic encephalopathy including its early cognitive features, while the Glasgow Coma Scale measures depth of unconsciousness and is blind to everything above it.
The Glasgow Coma Scale has no way of recording a shortened attention span, an altered sleep rhythm or asterixis, so a patient in West Haven grade I or II scores 15 on it. It becomes the more useful instrument at the severe end, where it resolves depth of coma more finely than a single grade IV category does, and intensive care teams reasonably use both. Where a patient is deeply obtunded, recording a Glasgow Coma Scale alongside grade IV adds information; at grades I to III it adds nothing.
West Haven Criteria vs Psychometric testing for minimal HE (PHES, Stroop, CFF)
They cover the range West Haven cannot see — a patient graded 0 may still have measurable cognitive impairment, and only testing will show it.
West Haven grade 0 is defined by a normal clinical examination, which sets the floor of the scale above the level at which impairment begins. Psychometric batteries such as PHES, the Stroop-based smartphone tests and critical flicker frequency detect minimal hepatic encephalopathy below that floor. This is not an academic distinction: minimal disease impairs driving, work performance and quality of life, and predicts progression to overt episodes. Use the grade for severity in an unwell patient; use testing when the question is whether a well-looking patient with cirrhosis is safe to drive.
West Haven Criteria vs CLIF-SOFA cerebral subscore
CLIF-SOFA consumes the West Haven grade rather than competing with it — the grade is the input, and grade III or above is what counts as cerebral organ failure.
Several composite scores take a West Haven grade directly: CLIF-SOFA uses it as the cerebral subscore and treats grade III or above as an organ failure, the AARC score bands it into three levels, and Child-Pugh scores it in three. This means an error in grading propagates into whichever composite score is driving the decision, which is a practical argument for grading carefully rather than approximating. It also means the grade is being asked to do a job it was not designed for — it was a trial endpoint, not a component of an organ-failure model.
Pearls & pitfalls
- Grade 0 does not mean unaffected. Minimal hepatic encephalopathy sits below the scale's floor and is only found by psychometric or neurophysiological testing — relevant for driving and work safety.
- Grade I is the least reliable grade. It requires knowing the patient's usual state, and two competent examiners frequently disagree; both guidelines acknowledge this rather than dispute it.
- Asterixis is a grade II finding, not a grade I one. Looking for it as the earliest sign delays recognition of covert disease.
- Hepatic encephalopathy is a diagnosis of exclusion. Grade the mental state, but exclude hypoglycaemia, sepsis, subdural haemorrhage, uraemia, Wernicke's and drug effects — the grade describes severity, not cause.
- Ammonia does not grade it. A normal ammonia argues against the diagnosis, but the level does not correlate well enough with grade to be used for monitoring, and treating a number rather than a patient is a recognised error.
- Take the highest grade whose features are present. Scoring the average of a mixed picture, or the most recent observation in a fluctuating one, understates severity.
- The grade is dynamic and can change within hours. A single recorded value without a time is close to useless for handover.
- Do not attribute a first presentation of grade III or IV to encephalopathy without imaging the head, particularly in a coagulopathic patient who may have fallen.
Critical actions
- Establish the baseline before grading. In an outpatient, ask a family member what has changed; grade I is invisible without that.
- At grade II or above, perform a diagnostic paracentesis if there is ascites, and culture blood and urine — infection is the most consequential precipitant and often has no localising signs.
- Review the drug chart for sedatives, opioids and benzodiazepines, including anything given for a recent procedure, and stop what can be stopped.
- Check glucose, sodium, potassium, creatinine and a septic screen before concluding the cause is hepatic; correct what is correctable.
- Image the head in a first episode of grade III or IV, in any patient with a fall or focal signs, and where the presentation does not fit.
- At grade III, assess the ability to protect the airway explicitly and move the patient to a setting where it can be managed, rather than reassessing later.
- Record the grade with a time, and re-grade after intervention — the trajectory is what tells you whether treatment is working.
- In recurrent overt episodes without a precipitant, look for a portosystemic shunt and reconsider transplant assessment.
Why this score exists
The criteria were not designed as a classification system at all. They were the bedside severity scale used in a 1977 trial that needed to show whether lactulose or neomycin worked better, and their durability is partly an accident of being good enough and arriving first. That origin explains both their strengths and their limits: the anchors are things a clinician can see without equipment, which is why the scheme survived fifty years of practice, and the grades were never calibrated against an objective measure of cognition, which is why grade I remains contentious. The 2002 working party and both guideline revisions have kept the scale while adding the categories it lacks — minimal hepatic encephalopathy below its floor, and the covert/overt division across its middle — which is a fair description of how the field has chosen to patch a useful instrument rather than replace it.
About the creator
First author of the 1977 West Haven VA trial in which the grading was used
Led the lactulose-versus-neomycin study at the West Haven Veterans Administration hospital that introduced the grading scheme and gave it its name.
First author, 2002 Working Party final report
Chaired the working party that standardised hepatic encephalopathy nomenclature and defined minimal hepatic encephalopathy.
First author, 2014 AASLD/EASL practice guideline
Led the joint guideline that adopted West Haven grading and the covert/overt framework now used in practice.
Limitations
- Consensus-descriptive with no objective reference standard, so it has no measurable accuracy — only reproducibility, which is imperfect.
- Inter-observer agreement is poor at the covert end, and both the 2014 and 2022 guidelines say so explicitly rather than treating it as a solved problem.
- Grade I cannot be scored reliably without knowledge of the patient's baseline, which is often unavailable in an emergency presentation.
- The floor of the scale sits above the onset of impairment, so minimal hepatic encephalopathy is invisible to it by construction.
- Grade IV collapses a wide range of coma depth into one category, which is why intensive care teams add a Glasgow Coma Scale.
- The grades are ordinal, not interval — the clinical distance from grade I to II is not the same as from III to IV, and averaging or trending them arithmetically is unjustified.
- It describes severity only. It says nothing about cause, and nothing about whether the encephalopathy is actually hepatic.
- Fluctuation within a day means a single grade may not represent the patient, and no convention exists for recording a range.
If you are the patient
Hepatic encephalopathy is confusion caused by liver disease: when the liver cannot clear toxins properly, they affect how the brain works. The West Haven scale is how doctors record how severe it is, from grade 0 to grade IV. Grade 0 means nothing shows up on examination. Grade I is subtle — a bit less attentive, a changed sleep pattern, and often only noticeable to someone who knows you well. Grade II is when confusion becomes clear, with loss of track of the day or date and a flapping tremor of the hands. Grade III is heavy drowsiness where you can still be roused. Grade IV is unconsciousness. From grade II onwards, doctors both treat the confusion and look for what triggered it, because there is almost always a trigger — an infection, constipation, dehydration, bleeding, or a new medication such as a sleeping tablet or strong painkiller. That is worth knowing, because most triggers are treatable and several are avoidable. Two practical points: family members often notice grade I before any doctor does, so say if something seems different; and if you have liver disease, ask about testing for the mildest form before driving, because it can affect concentration without being obvious.
Frequently asked questions
What are the West Haven criteria?#
A five-level clinical grading of hepatic encephalopathy severity. Grade 0 is no detectable abnormality; grade I is trivial lack of awareness with a shortened attention span and altered sleep; grade II is lethargy, disorientation to time and obvious asterixis; grade III is somnolence to semi-stupor with a response to stimuli and gross disorientation; grade IV is coma.
What is the difference between covert and overt hepatic encephalopathy?#
Covert encephalopathy covers minimal hepatic encephalopathy and West Haven grade I — detectable by testing or by someone who knows the patient's baseline, but not by routine examination. Overt encephalopathy is grade II and above, where disorientation and asterixis make it apparent at the bedside. The boundary between grade I and grade II is where treatment and the search for a precipitant begin.
Which West Haven grade means treatment should start?#
Grade II. That is the threshold for overt encephalopathy and the point at which the guideline expects both treatment and an active search for a precipitant — infection, gastrointestinal bleeding, constipation, sedatives, diuretics or renal impairment. Grade I warrants review of precipitants and adherence but is often managed without escalating therapy.
Is asterixis a sign of grade I encephalopathy?#
No — obvious asterixis is a grade II finding. Waiting for a flap before diagnosing encephalopathy therefore misses the whole covert range. Grade I is characterised by a shortened attention span, impaired simple arithmetic, euphoria or anxiety and an altered sleep rhythm, none of which involve a tremor.
Can you have hepatic encephalopathy with a normal West Haven grade?#
Yes. Grade 0 is defined by a normal clinical examination, and minimal hepatic encephalopathy sits below that floor — detectable only by psychometric batteries such as PHES, Stroop-based tests or critical flicker frequency. It matters because it impairs driving and daily function and predicts progression to overt episodes.
Does the ammonia level correspond to the West Haven grade?#
Not closely enough to be useful. A normal ammonia argues against the diagnosis, but the level does not track severity well and should not be used to monitor response — the grade and the clinical trajectory do that. Repeatedly measuring ammonia to titrate treatment is a common but unsupported practice.
How reliable is West Haven grading between different doctors?#
Reliable from grade II upward, where the anchors are objective findings, and poor at grade I, which depends on knowing the patient's baseline and on a subjective judgement of 'trivial' change. Both the 2014 AASLD/EASL guideline and the 2022 EASL guideline state this limitation directly and it is the main reason psychometric testing exists for the covert range.
Why do other liver scores ask for a West Haven grade?#
Because it is the standard way to quantify encephalopathy, so composite models take it as an input. Child-Pugh scores it in three bands, CLIF-SOFA uses it as the cerebral subscore and counts grade III or above as an organ failure, and the AARC score bands it into three levels. The practical implication is that a grading error carries through into whichever composite score is being used to make the decision.
References
Original / primary reference
- Conn HO, Leevy CM, Vlahcevic ZR, Rodgers JB, Maddrey WC, Seeff L, Levy LL. Comparison of lactulose and neomycin in the treatment of chronic portal-systemic encephalopathy: a double blind controlled trial. Gastroenterology. 1977;72(4):573-583 (the trial in which the West Haven grading was introduced).
- Ferenci P, Lockwood A, Mullen K, Tarter R, Weissenborn K, Blei AT. Hepatic encephalopathy — definition, nomenclature, diagnosis, and quantification: final report of the Working Party at the 11th World Congresses of Gastroenterology, Vienna, 1998. Hepatology. 2002;35(3):716-721.
Clinical practice guidelines
- Vilstrup H, Amodio P, Bajaj J, Cordoba J, Ferenci P, Mullen KD, Weissenborn K, Wong P. Hepatic encephalopathy in chronic liver disease: 2014 practice guideline by the American Association for the Study of Liver Diseases and the European Association for the Study of the Liver. Hepatology. 2014;60(2):715-735.
- European Association for the Study of the Liver. EASL Clinical Practice Guidelines on the management of hepatic encephalopathy. J Hepatol. 2022;77(3):807-824.