Critical results
For critical results being sent internally within the Hospital, we provide a telephone service, 24 hours a day, seven days a week.
All results will be telephoned 24 hours a day if they meet the criteria stated below.
Haematology
Inpatients
All haematology results meeting the criteria 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 over.
Analyte
Hb
Platelet count
Suspected leukaemia
Neutrophils
Glandular fever screen
Malaria screen
Emergency Sickle Screen
INR
APTT Ratio
Fibrinogen
DDimer
Critical limit(s)
<70g/l or >200g/l
<50 x 109/l or >1000 x 109/l
Blasts, high WBC, etc
<1.0 x 109/l or >30 x 109/l
Positive
Positive
Positive or negative
>5.0
>4.5
<1.5g/l or >11g/l
>20.0ug/ml
GP results
All GP results meeting the critical criteria will be telephoned during the "normal working" day. Please refer to the discipline-specific sections for detailed information.
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 over.
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
Hb
Platelet count
Suspected leukaemia
Neutrophils
Malaria screen
Emergency Sickle Screen
INR
APTT Ratio
Fibrinogen
DDimer
Critical Limit(s)
<80g/l or >200g/l
<50 x 109/l or >1000 x 109/l
Blasts, high WBC, etc
<1.0 x 109/l or >30 x 109/l
Positive
Positive or negative
>5.0
>4.5
<1.5g/l or >11g/l
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 leukaemia
- 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
Inpatients
For critical results being sent internally within the Hospital, we provide a telephone service, 24 hours a day, seven days a week.
All results 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. The table indicates whether the results are telephoned to the GP out-of-hours service, or whether they are telephoned to the GP practise 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. This is because therapeutic ranges are only guides and there is wide inter-individual variation.
List of Biochemistry Critical Phoning Limits
ANALYTE | LOWER LIMIT (and below) | HIGHER LIMIT (and above) | Source |
| Sodium (mmol/L) | 120 <130 if <16yrs | 150 | RCPath 2017 RCPath 2017 for children as particular concern of risk of death in children with hypoNa |
| Potassium (mmol/L) | 2.5 | 6.5 | RCPath 2017 |
Potassium (mmol/L) Heart Failure Nurses** | 3.9 | 5.4 | Barnsley and Rotherham local agreement |
Potassium (mmol/L) GP Patients† |
| 6.0 When AKI >1 | RCPath 2017 On new occurrences |
| Glucose (mmol/L) | 2.5 | 25 (>15 if <16 years) | 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) | RCPath 2017 |
| Creatinine (umol/L) |
| 350 (>200 if <16 years) | 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 |
| All new occurrences |
AKI† GP Patients |
| 1 When Potassium >6.0 | RCPath 2017 All new occurrences |
| Serum Bicarbonate | 10 |
| RCPath 2017 GP only |
| Calcium - Adj (mmol/L) | 1.8 | 3.0 | Barnsley and Rotherham local agreement |
| PO4 (mmol/L) | 0.3 |
| RCPath 2017 Urgent inpatient, GP urgent, if OOH within 24 hours |
| Mg (mmol/L) | 0.4 |
| RCPath 2017 |
| CK (U/L) |
| 5000 unless ?MI | RCPath 2017 |
| ALT (U/L) |
| 735 | RCPath 2017 |
| AST (U/L) |
| 510 (>500 if <16 years)* | RCPath 2017 |
| Amylase (U/L) |
| 590 | RCPath 2017 |
| Lactate |
| >4.0 | RCPath 2017 |
| Lipase (U/L) |
| 265 | RCPath 2017 |
| Bilirubin (umol/L) |
| 300 | Barnsley and Rotherham local agreement |
| Conjugated Bilirubin (umol/L) |
| 25 | Neonates only RCPath 2017 |
| Triglyceride (mmol/L) |
| 20 | RCPath 2010 |
| Ammonia (umol/L) |
| >40 | Barnsley and Rotherham local agreement |
| Bile Acids*** (umol/L) |
| 14 | Barnsley and Rotherham local agreement |
| Iron (umol/L) |
| 55 | Barnsley and Rotherham local agreement |
| Uric Acid/Urate (umol/L) |
| 340 | Ante-natal only RCPath 2017 |
| CRP (mg/L) |
| 300 | RCPath 2017 |
| Troponin I High Sensitivity (ng/L) |
| 120 | RCPath 2017, Local agreement |
| Troponin I High Sensitivity (ng/L) from GP |
| 3 | Local agreement |
| Cortisol (nmol/L) | 50 unless part of O/N Dexamethasone suppression test |
| RCPath 2017 |
| Cortisol (nmol/L) (SST 30 minutes) | 250 |
| RCPath 2017 – To be phoned by Biochemistry Consultant authorising the DFT |
| fT4 (pmol/L) | 5 | 30 | Barnsley and Rotherham local agreement In patient within 2 hours GP/ Out pt next working day |
| fT3 |
| 10 if FT4 normal with suppressed TSH | Barnsley and Rotherham local agreement In patient within 2 hours GP/ Out pt next working day |
| TSH (mIU/L) |
| 50 for 1st time | Barnsley and Rotherham local agreement In patient within 2 hours GP/ Out pt next working day |
| Paracetamol (mg/L) |
| If detected | Barnsley and Rotherham local agreement |
| Salicylate (mg/L) |
| If detected | Barnsley and Rotherham local agreement |
| Phenytoin (mg/L) |
| 25 | RCPath 2017 |
| Carbamazepine (mg/L) |
| 25 | RCPath 2010 |
| Theophylline (mg/L) |
| 25 | RCPath 2017 |
| Digoxin (ug/L) |
| 2.5 | RCPath 2017 |
| Lithium (mmol/L) |
| 1.5 | RCPath 2017 |
| Phenobarbitone (mg/L) |
| 70 | RCPath 2010 |
| Valproate (mg/L) |
| 150 for 1st time | Barnsley and Rotherham local agreement |
| PBG |
| Positive | Barnsley and Rotherham local agreement |
| Ethanol (mg/L) |
| Detected | Barnsley and Rotherham local agreement |
| Osmolality (mosm/kg) | 270 | 300 | Barnsley and Rotherham local agreement |
| Blood Gas†† | All results where paper reports given |
| Barnsley and Rotherham local agreement |
| HbA1c |
| 120mmol/mol | SY&B local Agreement for first-time HbA1c results without a glucose requested / not known diabetic |
Please note, this list is not exhaustive. Results may be phoned if professional judgement by lab staff deems any changes to be significantly different to previous results, even though results are within the stated limits
Generally, the local agreement results in more results being phoned than is advised by the RCPath.
**Heart failure patients that have been identified with a sticker on the request card are phoned at lower potassium limits.
***Bile acids need to be phoned at all times, escalate to on-call Obs & Gynae registrar if no answer from antenatal unit.
† Potassium result >6.0 with AKI should be telephoned for all GP patients on first occurrence.