Urgent Chemical Pathology results
The Chemical Pathology department will make every effort to inform clinicians of critical blood results which require urgent clinical intervention (These critical blood result phoning limits have been set in accordance with Royal College of Pathology guidelines and following consultation with CCG clinical lead and secondary care clinicians).
The stated limits serve as a guide only (below;) they are not exhaustive and laboratory staff should check with the Chemical Pathology Consultant, if unsure as to the suitability of communicating given data-sets by phone.
Generally, if the observed data is consistent with past (deranged) findings that have already been communicated as a matter of urgency previously, then the most recent results will not typically be phoned but will instead be released in the normal manner unless specifically requested otherwise.
Critical result limits
|
Analyte |
In-patients |
GP/ Out-patients |
Comments |
|---|---|---|---|
|
ALT (U/L) |
≥600 (15x ULN) |
As for in-patients |
|
|
Ammonia (umol/L) |
100 |
N/A |
|
|
Amylase (U/L) |
≥250 |
As for in-patients |
|
|
AST (U/L) |
≥675(15x ULN) |
As for in-patients |
|
|
|
|
|
|
|
Bilirubin – Direct/Conj (µmol/L) |
≥25 Neonates |
As for in-patients |
|
|
Calcium corrected (mmol/L) |
≤1.8 ≥3.5 |
As for in-patients |
Primary Care: If out of hours (OOHs) then communication next day to GP or GP OOHs service. Calcium levels ≥ 3.5 mmol/L may warrant more immediate communication with Primary Care as agreed by local consensus. |
|
CK (U/L) |
≥5000 |
As for in-patients |
Changed in line with RCPath guidelines, previous cut off was 2000 U/L |
|
Cortisol (nmol/L) |
≤50.0
≤250 |
As for in-patients |
Telephoning not required if post-dexamethasone suppression test As part of short synacthen test. Cut point used may need to be specific to assay being used |
|
Creatinine (µmol/L) |
≥354 (≥ 200 if < 16 yrs) |
≥354 (≥ 200 if < 16 yrs) |
Agree, by local consensus, higher thresholds for phoning results in patients with known kidney disease including those on dialysis. Specific local cut points likely to be required for babies and neonates. |
|
CRP (mg/L) |
|
≥300 |
Primary care/GP’s only |
|
CSF Xanthochromia |
Phone all results |
N/A |
Refer to LP-BIO-P716 for sample collection details |
|
Digoxin (nmol/L) |
≥3.0 |
As for in-patients |
Check that timing is > 6 hrs since last dose. Phone if >2.0 if [K+] or [Mg2+] low and/or in renal impairment |
|
Ethanol (mg/dl) |
≥400 |
N/A |
|
|
Glucose (mmol/L) |
≤2.5 ≥25.0 (≥15 mmol/L if <16 y
|
≥25.0 if no previous record, new diabetic
30mmol/L in known type 2 DM |
Exact cut points and response should be determined locally. Glucose results < 2.5 mmol/L from primary care may be less crucial to phone immediately. For GPs and OPD, upper cut point of 30 mmol/L in known type 2 DM may be more appropriate. |
|
Iron (µmol/L) –Only applicable to high risk patients e.g bariatric surgery patients on long term high doses of iron supplements, pregnant patient |
≥50 Adults |
As for in-patients – contact on-call consultant in first instance |
|
|
Lithium (mmol/L) |
≥1.5 |
As for in-patients |
|
|
Magnesium (mmol/L) |
≤0.4 |
As for in-patients |
|
|
Paracetamol (mg/L) |
≥25.0 |
As for in-patients |
Note time of ingestion if given |
|
Phenytoin (µmol/L) |
≥80 if [Alb] >40g/L ≥60 if [Alb] <35g/L |
As for in-patients |
|
|
Phosphate (mmol/L) |
≤0.3 |
As for in-patients |
|
|
Potassium (mmol/L) |
≤2.5 ≥6.5 |
As for in-patients*
|
Exclude haemolysis/old samples/EDTA contamination first. Agree, by local consensus, higher thresholds for phoning results in patients with known kidney disease including those on dialysis.(Please suggest if you agree to a higher phoning limit for this category of patients) |
|
Salicylate (mg/L) |
≥300.0 |
As for in-patients |
Note time of ingestion |
|
Sodium (mmol/L) |
≤120 ≥160 |
<120 >160 |
≤130 mmol/L or >150 if <16y |
|
Theophylline (µmol/L) |
≥130 Adults ≥65 Children |
As for in-patients |
|
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|
|
|
|
|
Troponin I (ng/L) |
N/A |
≥16 – Female ≥34 – Male |
|
|
Urate (mmol/L) |
|
≥0.34 |
Ante –natal patients only |
|
Urea (mmol/L) |
30 (≥ 10 if< 16 yrs) |
Same as inpatients |
Agree, by local consensus, higher thresholds for phoning results in patients with known kidney disease including those on dialysis. Specific local cut points likely to be required for babies and neonates |
|
For all out of hours clinical virology advice, please contact the infectious diseases registrar at BartsHealth (via Royal London switchboard. Short dialling code 6004) |
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*(<2.8 >6.5 if OOH - all out of range results (2.5-6.5) to be phoned to GP next working day regardless)