Telephoning of Critical Results
In the hospital, all results will be telephoned 24 hours a day if they meet the criteria stated below. All GP results meeting the telephone criteria will be telephoned during the normal working day. Please refer to the discipline-specific sections for detailed information.
Haematology
In-patients:
All Haematology results meeting the criteria in the table below will be phoned to the requesting clinician, except where the results are persistently abnormal. In these cases, only a change to results that may affect patient management will be phoned.
| Analyte | Critical Limit(s) |
| Hb | <70g/l or >200g/l |
| Platelet count | <50 x 109/l or >1000 x 109/l |
| Suspected leukaemia | Blasts,high WBC,etc. |
| Neutrophils | <1.0 x 109/l or >30 x 109/l |
| Glandular fever screen | Positive |
| Malaria screen | Positive |
| Emergency Sickle Screen | Positive or negative |
| INR | >5.0 |
| APTT Ratio | >4.5 |
| Fibrinogen | <1.5g/l or >11g/l |
| DDimer | >20.0ug/ml |
GP Results:
Results phoned to the out-of-hours service should also be phoned to the GP surgery the following morning to verify that action has been taken. All Haematology results meeting the criteria in the table below will be phoned to the requesting clinician, or the out-of-hours service, except where the results are persistently abnormal. In these cases, only a change to results that may affect patient management will be phoned.
In all cases, if there is concern that the patient’s condition may result in the patient being contacted by an on-call clinician, this should be made clear to the patient during their appointment.
| Analyte | Critical Limit(s) |
| Hb | <80g/l or >200g/l |
| Platelet count | <50 x 109/l or >1000 x 109/l |
| Suspected leukaemia | Blasts,high WBC,etc. |
| Neutrophils | <1.0 x 109/l or >30 x 109/l |
| Malaria screen | Positive |
| Emergency Sickle Screen | Positive or negative |
| INR | >5.0 |
| APTT Ratio | >4.5 |
| Fibrinogen | <1.5g/l or >11g/l |
| DDimer | Any result >=0.5ug/ml |
Additional considerations
In addition to contacting the requesting clinician, the following cases will be promptly referred to a Consultant Haematologist for direct clinical liaison and advice:
• Newly presented leukaemias
• Newly presented malaria infection
• Positive sickle haemoglobin screen in patients about to undergo anaesthesia
• Any low factor assay result for patients undergoing an emergency procedure.
• Persistently prolonged isolated APTT or PT result where there is an acute bleeding risk to the patient (when the patient is not on anticoagulant therapy).
Chemical Pathology
In-patients:
In the hospital, all results in the below table will be telephoned 24 hours a day if they meet the criteria stated in the table below.
GP Results:
The below table identifies the arrangements for telephoning GP results out-of-hours, indicating whether the results are telephoned to the GP out-of-hours service, or whether they are telephoned to the GP practice the following working day.
Therapeutic drug monitoring results will be telephoned (as specified below) if they are significantly outside the therapeutic range. It must be stressed, however, that the patient and not the biochemistry result should be treated as therapeutic ranges are only guides and there is wide inter-individual variation.
| ANALYTE | LOWER LIMIT (and below) | HIGHER LIMIT (and above) | GP Telephoning Out of Hours | Source |
|---|---|---|---|---|
| Sodium (mmol/L) | 120 <130 if <16yrs | 150 | GP Out of Hours Service | RCPath 2017 RCPath 2017 for children as particular concern of risk of death in children with hypoNa |
| Potassium (mmol/L) | 2.5 | 6.5 | GP Out of Hours Service | RCPath 2017 |
| Potassium (mmol/L) Heart Failure Nurses** | 3.9 | 5.4 | GP Out of Hours Service | Barnsley and Rotherham local agreement |
| Potassium (mmol/L) GP Patients† | 6.0 When AKI >1 | GP Out of Hours Service | RCPath 2017 On new occurrences |
|
| Glucose (mmol/L) | 2.5 | 25 (>15 if <16 years) | GP Out of Hours Service | RCPath 2017 State 30mmol/L for GP known DM patients Glucose results < 2.5 may be less crucial to phone immediately |
| Urea (mmol/L) | 30 (>10 if <16 years) | GP Out of Hours Service | RCPath 2017 | |
| Creatinine (umol/L) | 350 (>200 if <16 years) | GP Out of Hours Service | RCPath 2017 (actually states 354 umol/L) higher thresholds for known CKD or pt on dialysis. Need specific local points for babies. |
|
| AKI | Level of 2 or above | GP Out of Hours Service | All new occurrences | |
| AKI† GP Patients | 1 When Potassium >6.0 | GP Out of Hours Service | RCPath 2017 All new occurrences |
|
| Serum Bicarbonate | 10 | Next Working Day | RCPath 2017 GP only |
|
| Calcium - Adj (mmol/L) | 1.8 | 3 | GP Out of Hours Service | Barnsley and Rotherham local agreement |
| PO4 (mmol/L) | 0.3 | GP Out of Hours Service | RCPath 2017 Urgent inpatient, GP urgent, if OOH within 24 hours |
|
| Mg (mmol/L) | 0.4 | GP Out of Hours Service | RCPath 2017 | |
| CK (U/L) | 5000 unless ?MI | GP Out of Hours Service | RCPath 2017 | |
| ALT (U/L) | 735 | GP Out of Hours Service | RCPath 2017 | |
| AST (U/L) | 510 | GP Out of Hours Service | RCPath 2017 | |
| Amylase (U/L) | 590 | GP Out of Hours Service | RCPath 2017 | |
| Lipase (U/L) | 265 | GP Out of Hours Service | Barnsley and Rotherham local agreement | |
| Bilirubin (umol/L) | 300 | Next Working Day | Barnsley and Rotherham local agreement | |
| Conjugated Bilirubin (umol/L) | 25 | Next Working Day | Neonates only RCPath 2017 |
|
| Triglyceride (mmol/L) | 20 | Next Working Day | RCPath 2010 | |
| Ammonia (umol/L) | All | Next Working Day | Barnsley and Rotherham local agreement | |
| Bile Acids (umol/L) | 14 | Next Working Day | Barnsley and Rotherham local agreement | |
| Iron (umol/L) | 55 | Next Working Day | Barnsley and Rotherham local agreement | |
| Uric Acid/Urate (umol/L) | 340 | Next Working Day | Ante-natal only RCPath 2017 | |
| CRP (mg/L) | 300 | GP Out of Hours Service | RCPath 2017 | |
| Troponin I High Sensitivity (ng/L) | 120 | GP Out of Hours Service | RCPath 2017, Local agreement | |
| GP Troponin I High Sensitivity (ng/L) | >3 advise to call duty Biochemist for advice | GP Out of Hours Service | Barnsley and Rotherham local agreement | |
| Cortisol (nmol/L) | 50 unless part of O/N Dexamethasone suppression test | Next Working Day | RCPath 2017 | |
| Cortisol (nmol/L) (SST 30 minutes) | 250 | Next Working Day | RCPath 2017 – To be phoned by Biochemistry Consultant authorising the DFT | |
| fT4 (pmol/L) | 5 | 30 | Next Working Day | Barnsley and Rotherham local agreement In patient within 2 hours GP/ Out pt next working day |
| fT3 | 10 if FT4 normal with suppressed TSH | Next Working Day | Barnsley and Rotherham local agreement In patient within 2 hours GP/ Out pt next working day |
|
| TSH (mIU/L) | 50 for 1st time | Next Working Day | Barnsley and Rotherham local agreement In patient within 2 hours GP/ Out pt next working day |
|
| Paracetamol (mg/L) | If detected | GP Out of Hours Service | Barnsley and Rotherham local agreement | |
| Salicylate (mg/L) | If detected | GP Out of Hours Service | Barnsley and Rotherham local agreement | |
| Phenytoin (mg/L) | 25 | Next Working Day | RCPath 2017 | |
| Carbamazepine (mg/L) | 25 | Next Working Day | RCPath 2010 | |
| Theophylline (mg/L) | 25 | Next Working Day | RCPath 2017 | |
| Digoxin (ug/L) | 2.5 | GP Out of Hours Service | RCPath 2017 | |
| Lithium (mmol/L) | 1.5 | GP Out of Hours Service | RCPath 2017 | |
| Phenobarbitone (mg/L) | 70 | Next Working Day | RCPath 2010 | |
| Valproate (mg/L) | 150 for 1st time | Next Working Day | Barnsley and Rotherham local agreement | |
| PBG | Positive | Next Working Day | Barnsley and Rotherham local agreement | |
| Ethanol (mg/L) | Detected | Next Working Day | Barnsley and Rotherham local agreement | |
| Osmolality (mosm/kg) | 270 | 300 | Next Working Day | Barnsley and Rotherham local agreement |
| Hba1c (mmol/mol) | 120 | GP Out of Hours Service | SY&B local Agreement for first-time HbA1c results without a glucose requested / not known diabetic | |
| Blood Gas | All | Next Working Day | Barnsley and Rotherham local agreement |
**Rotherham Heart failure patients that have been identified with a sticker on the request card are phoned at different potassium limits.