Critical Results

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 will also be phoned to the GP surgery the following morning to verify that action has been taken.

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

 

Chemical Pathology

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
(and below)

HIGHER LIMIT
(and above)

Sodium  (mmol/L)

120

150

Potassium  (mmol/L)

2.5

6.5

Glucose  (mmol/L)

2.5

25

 

Out-of-hours – Unless known diabetics

Urea  (mmol/L)

 

30 for 1st time
(>10 if <16 years)

Creatinine  (umol/L)

 

400 for 1st time
(>200 if <16 years)

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

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.