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 |
| Platelet count | <50 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 | All |
| INR | >5.0 |
| INR for patients managed by anticoagulant service | >8.0 during rotine working. OOH, >5.0 or <1.5 |
| APTT Ratio | >4.5 |
| Fibrinogen | < 1.5g/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 |
| Platelet count | <50 x 109/l |
| Suspected leukaemia | Blasts,high WBC,etc. |
| Neutrophils | <1.0 x 109/l or >30 x 109/l |
| Glandular fever screen | Positive only if the clinical details indicate the patient requires hospital admission |
| Malaria screen | Positive |
| Emergency Sickle Screen | All |
| INR | >5.0 |
| APTT Ratio | >4.5 (or APTT >50) |
| Fibrinogen | < 1.5g/l |
| DDimer | Any result >0.5 |
Chemical Pathology
In the hospital, all results will be telephoned 24 hours a day if they meet the criteria stated below.
Out-of-hours, in the case of Chemical Pathology, only those highlighted in red will be telephoned urgently to either the practice if it remains open or to the GP out-of-hours service, all results not coloured red will be telephoned the following working day.
|
ANALYTE |
LOWER LIMIT |
HIGHER LIMIT |
| Sodium (mmol/L) |
120 |
150 |
| Potassium (mmol/L) |
2.5 |
6.0 |
| Glucose (mmol/L) |
2.5 |
25 |
|
Out-of-hours – Unless known diabetics |
||
| Urea (mmol/L) |
|
30 for 1st time |
| Creatinine (umol/L) |
|
400 for 1st time |
| AKI |
Level 2 and above |
|
| Serum Osmolality |
270 |
300 |
| Calcium – Adj (mmol/L) |
1.8 |
3.5 |
| PO4 (mmol/L) |
0.3 |
|
| Mg (mmol/L) |
0.4 |
|
| CK (U/L) |
>5000 unless ?MI |
|
| Albumin |
<20 |
|
| ALT and AST (U/L) |
600 or more for 1st time |
|
| Amylase (U/L) |
500 or more for 1st time |
|
| Bilirubin (umol/L) |
>300 for 1st time |
|
| Triglyceride (mmol/L) |
>20 |
|
| Ammonia (umol/L) |
All |
|
| Blood gases |
All |
|
| Bile Acids (umol/L) |
>14 for 1st time |
|
| Iron (umol/L) |
>55 for 1st time |
|
| Serum Uric Acid (umol/L) |
>800 |
|
| CRP (mg/L) |
>300 |
|
| Troponin I (ng/L) |
>40 |
|
| fT4 (pmol/L) |
>30 for 1st time |
|
| TSH (mIU/L) |
>30 for 1st time |
|
| Paracetamol (mg/L) |
If detected |
|
| Salicylate (mg/L) |
If detected |
|
| Phenytoin (mg/L) |
>25 |
|
| Carbamazepine (mg/L) |
>25 |
|
| Theophylline (mg/L) |
>25 |
|
| Digoxin (ug/L) |
>2.5 |
|
| Lithium (mmol/L) |
>1.5 |
|
| Phenobarbitone (mg/L) |
>70 |
|
| Valproate (mg/L) |
>150 for 1st time |
|
| PBG |
Positive |
|
Therapeutic drug monitoring results will be telephoned (as specified above) 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.